A prostate cancer cell
Just say nay to a PSA
Late last week, the American Urological Association announced that it no longer thinks men under the age of 55 should be routinely screened for prostate cancer with a prostate-specific antigen test or PSA.
For men between 55 and 69, it said, testing frequency should be based on a careful weighing of risks and benefits, a discussion best done with a doctor. For men over the age of 80, no testing is recommended. (Prostate cancer tends to be a slow-moving disease. After age 80, you’re more likely to die from something else.)
The AUA’s declaration, made during its annual national meeting in San Diego, marks a notable reversal of course. Two years ago, when the advisory U.S. Preventive Services Task Force released a preliminary report suggesting healthy men not be routinely screened with a PSA test, the AUA vehemently objected, and continued to do so as late as May of last year in various official statements.
Its position at that time was simple: While nobody would argue the PSA is a perfect test – misreadings can result in painful, unnecessary biopsies which may exacerbate cancer risk – it was the best test available, and had been used effectively to detect early-stage prostate cancer in thousands of men, perhaps saving their lives.
According to the AUA, the new guidelines are based upon a review of published scientific literature, rather than the Task Force’s collective medical opinion. The urology organization determined that at least for men ages 55 to 69, the test might measurably reduce their mortality rate of prostate cancer, which currently kills an estimated 30,000 American males each year. For everybody else, its efficacy is more debatable.
“There is general agreement that early detection, including prostate-specific antigen screening, has played a part in decreasing mortality from prostate cancer,” said Dr. H. Ballentine Carter, who chaired the panel that developed the guideline. “The randomized controlled trials are more mature at this point and there is more data available today than there was in 2009. It’s time to reflect on how we screen men for prostate cancer and take a more selective approach in order to maximize benefit and minimize harms.”
Killing cancer with radioactive microbes
The war on cancer is waged on many fronts, with many weapons, from chemotherapy and nanoparticles to monoclonal antibodies and targeted ultrasound.
In a new commentary published this week in PNAS, Aladar A. Szalay, PhD, in the Department of Radiation Oncology at UC San Diego Moores Cancer Center, and colleague Jochen Stritzker discuss a new (sort of) approach: Microorganisms carrying radioactive antibodies that infiltrate and kill cancer tumors and cells.
To be completely accurate, the work, described in the May 6 online issue of PNAS by Wilber Quispe-Tintaya and colleagues at Albert Einstein College of Medicine in New York City, is not entirely new. In 2009, Robert Hoffman, PhD, in the Department of Surgery at UC San Diego School of Medicine and colleagues reported on experiments with engineered salmonella bacteria, showing that it can kill mouse cancer cells, including metastases of pancreatic cancer.
But the latest Einstein College research is encouraging. It uses a different microorganism – an attenuated or weakened version of Listeria monocytogenes, a food-borne pathogen responsible for listeriosis - to which scientists attach radiolabeled antibodies, then inject the combination into mice with cancer. The reported results have been notable.
In mice injected with just the live L. monocytogenes, primary tumors were reduced in size by 20 percent and metastatic burden – the presence of cancer cells in the body – dropped by 40 percent. Mice injected with just the antibodies experienced no therapeutic effect. In combination, however, the bacteria-and-antibodies treatment reduced primary tumor size by 60 percent and detectable metastases by more than 90 percent.
Just as important, the approach showed no harmful side effects on healthy tissues or liver function. Szalay and Stritzker say the results should stimulate further experimentation, perhaps expanding to other bacteria and viruses with a particular preference and ability to infect and replicate in cancer cells, such as Escherichia coli.
Novick, Spitzer and Knowlton elected to NAS
Peter Novick, PhD, was elected yesterday to the National Academy of Sciences, created in 1863 by President Abraham Lincoln to provide the federal government with advice on matters related to science, engineering and medicine.
Novick, who came to UC San Diego School of Medicine in 2008 as the George E. Palade Endowed Chair of Cellular and Molecular Medicine, is noted for his groundbreaking work in the field of cell biology. Specifically, Novick has combined research in genetics and cell biology in yeast to investigate the mechanisms that regulate membrane trafficking along the secretory pathway – a series of steps used to move proteins out of a cell.
Membrane traffic is required for many essential functions, and its regulation is directly relevant to a broad range of human diseases including cancer, diabetes and neural degeneration.
Prior to coming to UC San Diego, Novick was a professor in the Department of Cell Biology at the Yale University School of Medicine for more than 20 years. He is a member of the American Academy of Arts and Sciences.
Joining Novick this year as new NAS members are Nicholas Spitzer, distinguished professor and vice chair of the neurobiology section in the Division of Biological Sciences at UC San Diego, and Nancy Knowlton, adjunct professor at the Scripps Institution of Oceanography at UC San Diego.
Spitzer studies neural plasticity, the ability of the brain to adapt to environmental changes. He is co-director of the Kavli Institute for Brain and Mind at UCSD and involved in the new BRAIN Initiative.
Knowlton is founding director of the Scripps Center for Marine Biodiversity and Conservation, launched in 2001 to study maritime issues such as pollution, overfishing and climate change. Knowlton is also Sant Chair of Marine Science at the Smithsonian National Museum of Natural History.
Anthophyllite asbestos - U.S. Geological Survey Denver Microbeam Laboratory
Writing in an editorial in the May issue of Environmental Health Perspectives, Wael K. Al-Delaimy, MD, PhD, a professor of epidemiology and chief of the Division of Global Health in the Department of Family and Preventive Medicine at UC San Diego School of Medicine, voices support for what he calls a long-overdue appeal by epidemiologists to ban asbestos worldwide.
Calling asbestos use a case of “global environmental injustice on a massive scale,” Al-Delaimy underscores the statement by the Joint Policy Committee (JPC) of the Societies of Epidemiology (SE) calling for the global ban of its use. The JPC-SE position is endorsed by its 10 member organizations, along with numerous major epidemiologic and public health associations.
For decades, asbestos has been known to cause lung cancer and other respiratory and cancerous conditions. According to Al-Delaimy, asbestos exposure was the number one occupational health problem until its use was banned in most of the developed world. However, an estimated 107,000 people still die each year from occupational exposure to asbestos and 125 million people are exposed to it – risking long-term disease.
Although asbestos use has been banned in most high-income countries because of its harmfulness, its use is increasing in middle- and low-income countries. According to the Al-Delaimy, this is because of the effective lobbying of the asbestos industry to prevent policies banning the substance, along with a “profound absence of education and awareness about asbestos’ harm in the countries using it the most.”
Likening it to the public health problem of tobacco use, Al-Delaimy said the asbestos industry hires consultants to promote scientific arguments in its favor, manufacture doubt about its risk and attack those advocates and scientists who speak out against the hazards of asbestos.
“In addition, the asbestos industry has established markets in countries that have inadequate legislation and weak public health programs and environmental organizations, enabling the sale of asbestos products,” Al-Delaimy writes in the editorial, adding that even countries that discourage use of asbestos-containing products often fail to ban exportation of the deadly products, “as if citizens from the less-developed countries are second-class global citizens.”
The personal costs to millions of people who become ill or die from exposure to asbestos products can harm emerging economies, impacting the global economy. More importantly, the practice of higher-income countries and their industries marketing asbestos to poorer, less education countries is unethical, Al-Delaimy said. To remain silent is “unacceptable,” and advocacy by environmental epidemiologists, scientists and public health professionals to ban asbestos is critical to bring legitimacy and accuracy to this important public health issue.
Al-Delaimy’s editorial is published in Volume 121 – Number 5, May 2013 issue of the journal Environmental Health Perspectives.
Human lungs are composed of roughly 700 million of tiny, elastic air sacs called alveoli that pass oxygen into the body and remove carbon dioxide from it. Photo courtesy of David Gregory and Debbie Marshall, Wellcome Images
The “cinnamon challenge” doesn’t sound ominous: You’re supposed to attempt to swallow a tablespoon of ground cinnamon within 60 seconds without drinking any fluids. How bad can that be?
In a recent paper in Pediatrics, researchers at the University of Miami describe what happens next: the ingested spice triggers a severe gag reflex, with immediate coughing, the sensation of burning in the mouth and likely vomiting.
All of which are apparently quite amusing to watch, judging from the popularity of Internet videos depicting kids (no surprise) attempting the challenge. In their paper, the University of Miami scientists reported at least 51,100 YouTube clips depicting people taking the challenge.
“One video was viewed more than 19 million times, predominantly by 13- to 24-year-olds, ages similar to people taking the Cinnamon Challenge and associated with the greatest need for conformity,” the researchers wrote.
If gagging and looking foolish were the sole results of swallowing a spoonful of cinnamon that would be one thing, but doctors say the health risks are much more serious: Inadvertently inhaling the ground cinnamon can result in choking, aspiration and pulmonary damage. Scores of challenge-takers have found themselves calling poison control centers, visiting emergency rooms - some have been hospitalized for collapsed lungs.
Cinnamon should be eaten, not inhaled. It’s a caustic power composed of cellulose fibers that do not dissolve or degrade in the lungs. The Miami scientists found no studies of cinnamon inhalation in humans, but did find one with rats. Inhaling the spice inflamed the rats’ lungs, predisposing delicate air sacs called alveoli and lung passages to lesions, thickening, loss of elasticity and scarring.
Scientists say that in people, the effects of inhaled cinnamon appear to be temporary and probably do not increase the risk of long-term damage, but in some they may trigger serious allergic reactions, including asthma, or worsen other existing lung conditions.
Big picture biology, version 3
Even as scientists probe ever more deeply into the fundamental constituents of life, it has become increasingly important to also step back and ponder how these parts comprise the whole. As this Technology Review story presciently noted in 2003, some of biology’s bigger secrets may only be revealed in the bigger picture.
One of the tools that has made it possible to intelligently and coherently grapple with massive amounts of biological data being produced is a free, open source software platform called Cytoscape, which enables researchers to visualize enormously complex networks of interacting molecules, their biological pathways and annotate them with revelatory data like gene expression profiles.
The first version of Cytoscape debuted in the early 2000s. In the years since, roughly 1,600 scientific papers citing the software have been published. Each year an estimated 300-400 new ones appear.
They’ve just released Cytoscape v3, which you can read more about here. Though originally intended for biological research, Cytoscape is increasingly used by scientists doing complex network analyses, including those of social networks.