30 May 2018
WEDNESDAY, May 30, 2018 (HealthDay News) — Exposure to triclosan — a chemical in some shampoos and toothpastes — might raise the risk for colon inflammation and colon cancer, at least in mice, researchers say. New study results “suggest that triclosan could have adverse effects on gut health,” said study leader Guodong Zhang, a food scientist at the University of Massachusetts Amherst. Triclosan is a common antibacterial agent. It’s often used in hygiene and cosmetic products. Triclosan is also found in some clothing and kitchenware, according to the U.S. Food and Drug Administration. The FDA no longer allows triclosan in hand soaps, but it’s still present in other household products, such as dish soap. Working with laboratory mice, Zhang and his colleagues concluded that triclosan could alter gut microbiota, or the types of bacteria living in the intestines. These changes could lead to inflammation, more severe colitis symptoms and colitis-associated colon cancer cell growth in mice, the study authors said in a university news release. Colitis refers to colon inflammation. The team warned that triclosan should be monitored more closely. Study co-first author, Haixia Yang, a postdoctoral fellow at UMass Amherst, said, “Because this compound is so widely used, our study suggests that there is an urgent need to further evaluate the impact of triclosan exposure on gut health.” It’s important to note, however, that the results of animal studies aren’t always applicable to humans. In several mouse models, the researchers found that triclosan triggered inflammation and tumor formation in the colon. Triclosan also increased development of inflammatory bowel disease (IBD) in the mice, suggesting that IBD patients may need to reduce exposure to this compound, the researchers said. Triclosan had no effect, however, in models involving germ-free mice or mice that were genetically engineered to lack a specific receptor that is critical for gut bacteria communications, the investigators found. According to Zhang, “This is strong evidence that gut microbiota is required for the biological effects of triclosan.” Just how common is triclosan? It’s in more than 2,000 consumer products. And the chemical was detected in roughly 75 percent of urine samples tested in a U.S. National Health and Nutrition Examination Survey, the study authors noted. It’s also one of the leading pollutants in rivers in the United States. The study was published May 30 in the journal Science Translational Medicine. More information The U.S. Food and Drug Administration has more on triclosan.
19 April 2018
THURSDAY, April 19, 2018 (HealthDay News) — Tattoos serve many purposes, perhaps expressing artistry, loyalty or love. Now, scientists working with mice say they’ve engineered a medical “tattoo” that can screen for early signs of major disease. The biomedical tattoo is made up of cells embedded with sensors that measure levels of blood calcium. It’s initially invisible when implanted under the skin. But the sensors become apparent if blood calcium levels rise. This indicates a condition called hypercalcemia, which is a marker for several cancers and other major diseases. “Forty percent of all cancers — including colon cancer, lung cancer, breast cancer and prostate cancer — disrupt calcium balance (homeostasis),” said study lead author Martin Fussenegger. “The biomedical tattoo is designed to catch mild hypercalcemia,” which produces no symptoms, he said. Appearance of the tattoo may signal that some of those cancers may start to develop, said Fussenegger, of ETH Zurich’s department of biosystems science and engineering in Basel, Switzerland. When elevated blood calcium persists, the implant releases melanin, producing a telltale dark patch on the skin, he said. (Melanin is a dark pigment responsible for tanning.) But whether this is just a fun gimmick or a reliable diagnostic tool remains to be seen. Dr. Janice Dutcher is a medical oncologist with the Cancer Research Foundation in New York City. She described the innovation as a “neat gimmick.” “I guess in the context of looking for new and inventive ways to screen for disease, it’s a reasonable idea,” she said. “It’s always nice to try and conceive of a new, simple and accurate way to screen for disease.” But Dutcher cautioned that screening for high calcium levels is not always an effective way to detect cancer early. Some cancers — kidney cancer, for example — only prompt high calcium after the disease has progressed, she said. Dr. Norman Edelman, senior medical advisor for the American Lung Association, seconded that point. In his experience, “the bulk” of tumor-related hypercalcemia occurs at a late stage, when cancer has spread. “It is also a late finding in kidney failure,” he added. “So this is really fun science. But I would not spend a lot to license the patent,” Edelman said. To test their design, the researchers implanted the engineered cells under the skin of mice with either cancerous tumors that cause hypercalcemia or tumors that do not alter calcium blood levels. The tattoos only surfaced on the skin of mice with elevated blood calcium levels, according to the report. In theory, said Fussenegger, a tattoo diagnosis would happen at such an early stage of disease “that over 95 percent of the above-mentioned cancer types will be cured.” He and his colleagues were “impressed by the precision and sensitivity of the tattoo,” he said. A skin patch arose only when high calcium levels persisted, he explained, adding this would reduce the likelihood of false diagnoses. Still, “animal experiments do not always translate to people,” Fussenegger acknowledged. Human trials are set to begin within five years, he said. The goal is a human tattoo “universal system” that could detect multiple health issues at once. If all goes according to plan, Fussenegger predicted it could be available within 10 to 15 years. Besides cancer, Fussenegger said the approach could be linked to other slow-developing diseases. These might include neurodegenerative disorders like Parkinson’s and Alzheimer’s, he said. The findings were published April 18 in the journal Science Translational Medicine. More information There’s more on screening for cancer at the U.S. Centers for Disease Control and Prevention.