sábado, 4 de agosto de 2018
segunda-feira, 30 de julho de 2018
Gut bacteria byproduct protects against Salmonella, study finds
Date: July 26, 2018 Source: Stanford Medicine Summary: Researchers have identified a molecule that serves as natural protection against one of the most common intestinal pathogens, Salmonella.
Salmonella illustration (stock image). Salmonella bacteria cause about 1.2 million illnesses a year, but a new Stanford study identified a molecule that offers natural protection against the pathogen.
Credit: © sveta / Fotolia
Researchers at the Stanford University School of Medicine have identified a molecule that serves as natural protection against one of the most common intestinal pathogens.
Propionate, a byproduct of metabolism by a group of bacteria called the Bacteroides, inhibits the growth of Salmonella in the intestinal tract of mice, according to the researchers. The finding may help to explain why some people are better able to fight infection by Salmonella and other intestinal pathogens and lead to the development of better treatment strategies.
A paper describing the work will be published July 26 in Cell Host and Microbe.
The researchers determined that propionate doesn't trigger the immune response to thwart the pathogen. Instead, the molecule prolongs the time it takes the pathogen to start dividing by increasing its internal acidity.
Salmonella infections often cause diarrhea, fever and abdominal cramps. Most people recover within four to seven days. However, the illness may be severe enough to require hospitalization for some patients.
Salmonella causes about 1.2 million illnesses, 23,000 hospitalizations and 450 deaths nationwide each year, according to the Centers for Disease Control and Prevention. Most cases are caused by contaminated food.
Different responses to exposure
"Humans differ in their response to exposure to bacterial infections. Some people get infected and some don't, some get sick and others stay healthy, and some spread the infection while others clear it," said Denise Monack, PhD, professor of microbiology and immunology and the senior author of the paper. "It has been a real mystery to understand why we see these differences among people. Our finding may shed some light on this phenomenon."
For years, scientists have been using different strains of mice to determine how various genes might influence susceptibility to infection by intestinal pathogens. But this is the first time that researchers have looked at how the variability of gut bacteria in these mice might contribute to their different responses to pathogens.
"The gut microbiota is an incredibly complex ecosystem. Trillions of bacteria, viruses and fungi form complex interactions with the host and each other in a densely packed, heterogeneous environment," said Amanda Jacobson, the paper's lead author and a graduate student in microbiology and immunology. "Because of this, it is very difficult to identify the unique molecules from specific bacteria in the gut that are responsible for specific characteristics like resistance to pathogens."
From mice to men
The scientists started with an observation that has been recognized in the field for years: Two inbred strains of mice harbor different levels of Salmonella in their guts after being infected with the pathogen. "The biggest challenge was to determine why this was happening," Jacobson said.
First, they determined that the differences in Salmonella growth could be attributed to the natural composition of bacteria in the intestines of each mouse strain. They did this by performing fecal transplants, which involved giving mice antibiotics to kill off their usual composition of gut bacteria and then replacing the microbial community with the feces of other mice, some of whom were resistant to Salmonella infection. Then, the researchers determined which microbes were responsible for increased resistance to Salmonella infection by using machine-learning tools to identify which groups of bacteria were different between the strains.
They identified a specific group of bacteria, the Bacteroides, which was more abundant in mice transplanted with the microbiota that was protective against Salmonella. Bacteroides produce short-chain fatty acids such as formate, acetate, butyrate and propionate during metabolism, and levels of propionate were threefold higher in mice that were protected against Salmonella growth. Then, the researchers sought to figure out whether propionate protected against Salmonella by boosting the immune system like other short-chain fatty acids do.
The scientists examined their Salmonella model for the potential impact of propionate on the immune system but found that the molecule had a more direct effect on the growth of Salmonella. Propionate acts on Salmonella by dramatically decreasing its intracellular pH and thus increasing the time it takes for the bacterium to start dividing and growing, the study found.
"Collectively, our results show that when concentrations of propionate, which is produced by Bacteroides, in the gut are high, Salmonella are unable to raise their internal pH to facilitate cellular functions required for growth," Jacobson said. "Of course, we would want to know how translatable this is to humans."
Reducing the impact of Salmonella
"The next steps will include determining the basic biology of the small molecule propionate and how it works on a molecular level," Jacobson said. In addition, the researchers will work to identify additional molecules made by intestinal microbes that affect the ability of bacterial pathogens like Salmonella to infect and "bloom" in the gut. They are also trying to determine how various diets affect the ability of these bacterial pathogens to infect and grow in the gut and then shed into the environment. "These findings will have a big impact on controlling disease transmission," Monack said.
The findings could also influence treatment strategies. Treating Salmonella infections sometimes require the use of antibiotics, which may make Salmonella-induced illness or food poisoning worse since they also kill off the "good" bacteria that keep the intestine healthy, according to Monack. Using propionate to treat these infections could overcome this limitation. "Reducing the use of antibiotics is an added benefit because overuse of antibiotics leads to increased incidence of antibiotic-resistant microbes," Monack said.
Other Stanford co-authors of the paper are postdoctoral scholar Manohary Rajendram, PhD; graduate students Lilian Lam, Fiona Tamburini, Will Van Treuren, Kali Pruss, Jared Honeycutt and Kyler Lugo; Trung Pham, MD, instructor of pediatrics and infectious diseases; life science researcher Russel Stabler; Donna Bouley, DVM, PhD, professor emeritus of comparative medicine; José Vilches-Moure, PhD, assistant professor of comparative medicine; senior research scientist Mark Smith, PhD; Justin Sonnenburg, PhD, associate professor of microbiology and immunology; Ami Bhatt, MD, PhD, assistant professor of medicine and of genetics; and KC Huang, PhD, associate professor of bioengineering and of microbiology and immunology.
Bhatt, Huang, Monack, Sonnenburg and Vilches-Moure are members of Stanford Bio-X. Bhatt, Huang, Monack and Sonnenburg are faculty fellows at Stanford ChEM-H. Bhatt, Bouley and Vilches-Moure are members of the Stanford Cancer Institute. Bhatt and Monack are members of the Stanford Child Health Research Institute. Vilches-Moure is a member of the Stanford Cardiovascular Institute. Bouley is an affiliate of the Stanford Woods Institute for the Environment. Sonnenburg and Huang are Chan Zuckerberg Biohub Investigators.
The study was funded by the National Institutes of Health (grants R01DK085025, T32GM007276, R01AI116059 and F32AI133917), the Paul Allen Stanford Discovery Center on Systems Modeling of Infection and the National Science Foundation.
Stanford's Department of Microbiology and Immunology also supported the work.
Story Source:
Materials provided by Stanford Medicine. Original written by Kimber Price. Note: Content may be edited for style and length.
Journal Reference:
Amanda Jacobson, Lilian Lam, Manohary Rajendram, Fiona Tamburini, Jared Honeycutt, Trung Pham, Will Van Treuren, Kali Pruss, Stephen Russell Stabler, Kyler Lugo, Donna M. Bouley, Jose G. Vilches-Moure, Mark Smith, Justin L. Sonnenburg, Ami S. Bhatt, Kerwyn Casey Huang, Denise Monack. A Gut Commensal-Produced Metabolite Mediates Colonization Resistance to Salmonella Infection. Cell Host & Microbe, 2018; DOI: 10.1016/j.chom.2018.07.002
Cite This Page:
Stanford Medicine. "Gut bacteria byproduct protects against Salmonella, study finds." ScienceDaily. ScienceDaily, 26 July 2018. <www.sciencedaily.com/releases/2018/07/180726162800.htm>.
Adherence to healthy diets associated with lower cancer risk
An analysis of four nutritional scores showed biggest benefit from diet that discourages alcohol
Date: July 26, 2018
Source: American Association for Cancer Research
Summary:
A diet that encourages both healthy eating and physical activity and discourages alcohol consumption was associated with a reduced overall cancer risk, as well as lower breast, prostate, and colorectal cancer risks.
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Omega-3s help keep kids out of trouble
How diet, biology can prevent bad, even criminal behavior
Date: July 24, 2018 Source: University of Massachusetts Lowell Summary: Something as simple as a dietary supplement could reduce disruptive, even abusive behavior, according to newly released research.
Something as simple as a dietary supplement could reduce disruptive, even abusive behavior, according to newly released research by a team led by a UMass Lowell criminal justice professor.
Giving children omega-3 fatty acid supplements reduces disruptive behavior, which in turn had a positive effect on their parents, making them less likely to argue with each other and engage in other verbal abuse, according to Jill Portnoy, an assistant professor in UMass Lowell's School of Criminology and Justice Studies.
"This is a promising line of research because omega-3 fatty acids are thought to improve brain health in children and adults. There is more to be learned about the benefits, but if we can improve people's brain health and behavior in the process, that's a really big plus," said Portnoy, noting that a recent research review found that omega-3 supplements do not affect cardiovascular health.
The new research, published in the scholarly journal Aggressive Behavior, is just one example of how Portnoy is studying biological and social factors that can help explain and predict impulsive and risky behavior. The goal is to help determine effective ways to intervene before anti-social behavior escalates into crime.
That work takes Portnoy into the heart of the "nature versus nurture" debate -- whether people who commit crimes have something in their physiological makeup that predisposes them to doing so or if social factors like abusive family situations lead them to it.
"Of course, it's both," she said, but exactly how is still to be determined. "Biology and social environment interact in complex ways that we're just beginning to figure out. Before we can design effective interventions, we need to do research to understand what's happening."
Portnoy is exploring such a connection through another research project that is looking at how a low resting heart rate may lead to anti-social behavior.
"My theory is that a low resting heart rate might be an acquired, adaptive trait: If you are subjected to chronic or frequent stress as a child, you adapt by lowering your heart rate. The lower heart rate protects you by blunting your reaction to stressful events, but it can also lead to stimulation-seeking behavior. In other words, a stressful environment may cause physiological changes that lead to an increase in aggressive and impulsive behavior, in addition to causing the behavior directly," she said.
Working with a counterpart at the University of Pennsylvania, where she earned her Ph.D. and taught before coming to UMass Lowell, Portnoy studied hundreds of youths in Pittsburgh, where she grew up. The researchers found that the youths with lower resting heart rates were more likely to act out as a form of sensation-seeking, including anti-social behavior, which can be especially problematic for individuals living where there are few options for positive forms of stimulation.
Portnoy, who now lives in Portsmouth, N.H., will continue her research on this topic this fall with the help of a dozen UMass Lowell undergrads who will intern with her on the Health, Stress and Behavior Study, researching the connection between stress, heart rate and behavior.
Through this study, Portnoy and her team will examine what she describes as a continuum of criminal behavior with the goal of finding new ways to prevent it.
"Many people break the law in small ways; for example, by driving a few miles over the speed limit. I'm interested in people who are behaving aggressively but not yet reaching the level of criminal behavior or maybe they're committing more serious crimes like theft or assault, but haven't been caught. They're still exacting a toll on society. And if we want to design more general social interventions, like teaching people healthier ways to adapt to stress, then we shouldn't just study those who get caught," said Portnoy.
Story Source:
Materials provided by University of Massachusetts Lowell. Note: Content may be edited for style and length.
Journal Reference:
Jill Portnoy, Adrian Raine, Jianghong Liu, Joseph R. Hibbeln. Reductions of intimate partner violence resulting from supplementing children with omega-3 fatty acids: A randomized, double-blind, placebo-controlled, stratified, parallel-group trial. Aggressive Behavior, 2018; DOI: 10.1002/ab.21769
Cite This Page:
University of Massachusetts Lowell. "Omega-3s help keep kids out of trouble: How diet, biology can prevent bad, even criminal behavior." ScienceDaily. ScienceDaily, 24 July 2018. <www.sciencedaily.com/releases/2018/07/180724174322.htm>.
Turmeric-derived eye drops could treat glaucoma: study
Date: July 24, 2018 Source: University College London Summary: A derivative of turmeric could be used in eye drops to treat the early stages of glaucoma, a new study finds.
A derivative of turmeric could be used in eye drops to treat the early stages of glaucoma, finds a new study led by UCL and Imperial College London researchers.
In the new Scientific Reports paper, the researchers report a new method to deliver curcumin, extracted from the yellow spice turmeric, directly to the back of the eye using eye drops, overcoming the challenge of curcumin's poor solubility.
The research team found the eye drops can reduce the loss of retinal cells in rats, which is known to be an early sign of glaucoma.
They are also investigating how the eye drops could be used as a diagnostic tool for a range of conditions.
"Curcumin is an exciting compound that has shown promise at detecting and treating the neurodegeneration implicated in numerous eye and brain conditions from glaucoma to Alzheimer's disease, so being able to administer it easily in eye drops may end up helping millions of people," said the study's lead author, Professor Francesca Cordeiro (UCL Institute of Ophthalmology, Western Eye Hospital and Imperial College London).
Glaucoma is a group of eye conditions affecting over 60 million people worldwide that leads to irreversible blindness in 1 in 10 cases. The condition mainly involves the loss of retinal ganglion cells, a type of neuron located near the surface of the retina. Stopping the loss of these cells early on has not yet been achieved, so it is a key focus of glaucoma research.
Curcumin has previously been shown to protect retinal ganglion cells when administered orally. For the current study, the researchers were seeking to find a more reliable method to deliver curcumin. Oral administration is difficult because curcumin has poor solubility, so it does not easily dissolve and get absorbed into the bloodstream, and would require people to take large amounts of tablets (up to 24 a day) that may cause gastrointestinal side effects.
The team developed a novel nanocarrier, wherein the curcumin is contained within a surfactant combined with a stabiliser, both of which are known to be safe for human use and are already in existing eye products. The nanocarrier can be used in eye drops to deliver much higher loads of curcumin than other products in development, increasing the drug's solubility by a factor of almost 400,000, and localises the curcumin in the eyes instead of throughout the body.
The researchers initially tested the product on cells that are used to model glaucoma, before conducting trials in rats with eye conditions involving the loss of retinal ganglion cells.
After twice-daily use of eye drops in the rats for three weeks, retinal ganglion cell loss was significantly reduced compared to matched controls, and the treatment was found to be well-tolerated with no signs of eye irritation or inflammation.
Having found an effective way to deliver curcumin, the researchers are hopeful that it could also be used to diagnose Alzheimer's disease, as curcumin is known to bind to the amyloid beta protein deposits implicated in Alzheimer's, and can be detected in the retina with fluorescence to highlight the malignant proteins.
"We are now researching diagnostic uses for these eye drops alongside other ways to visualise the retina, as eye tests can be an opportunity to detect signs of neurodegeneration with a simple, non-invasive test," said co-lead author Dr Ben Davis (UCL Institute of Ophthalmology and Imperial College London).
Professor Cordeiro added: "As we live longer, diseases such as glaucoma and Alzheimer's are steadily increasing. We believe our findings could make a major contribution at helping the lives of people affected by these devastating diseases."
The researchers received funding from the Medical Research Council and Dr. Werner Jackstädt-Stiftung.
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Materials provided by University College London. Note: Content may be edited for style and length.
Journal Reference:
Benjamin M. Davis, Milena Pahlitzsch, Li Guo, Shiama Balendra, Parth Shah, Nivedita Ravindran, Giulia Malaguarnera, Claudia Sisa, Ehtesham Shamsher, Hisham Hamze, Abdinasir Noor, Acom Sornsute, Satyanarayana Somavarapu, M. Francesca Cordeiro. Topical Curcumin Nanocarriers are Neuroprotective in Eye Disease. Scientific Reports, 2018; 8 (1) DOI: 10.1038/s41598-018-29393-8
Cite This Page:
University College London. "Turmeric-derived eye drops could treat glaucoma: study." ScienceDaily. ScienceDaily, 24 July 2018. <www.sciencedaily.com/releases/2018/07/180724110233.htm>.
How cannabis and cannabis-based drugs harm your brain
Date: July 23, 2018 Source: Lancaster University Summary: Long-term use of either cannabis or cannabis-based drugs impairs memory, say researchers. Their study has implications for both recreational users and people who use the drug to combat epilepsy, multiple sclerosis and chronic pain.
Cannabis (stock image).
Credit: © Iarygin Andrii / Fotolia
Long-term use of either cannabis or cannabis-based drugs impairs memory say researchers.
The study has implications for both recreational users and people who use the drug to combat epilepsy, multiple sclerosis and chronic pain.
They found that mice exposed to the drug long-term had "significant ... memory impairments" and could not even discriminate between a familiar and novel object.
There is little understanding of the potential negative side effects of long-term cannabinoid exposure, though it is already known that heavy, regular cannabis use increases the risk of developing mental health problems including psychosis and schizophrenia.
More and more people are using the drug long-term due to its legalisation in several countries, while more potent varieties are available for recreational users.
Researchers from Lancaster and Lisbon Universities studied the effects of the cannabinoid drug WIN 55,212-2 in mice and found that:
- Long-term exposure impairs learning and memory in the animals
- Brain imaging studies showed that the drug impairs function in key brain regions involved in learning and memory
- Long-term exposure to the drug impairs the ability of brain regions involved in learning and memory to communicate with each other, suggesting that this underlies the negative effects of the drug on memory
Dr Neil Dawson, the lead researcher from Lancaster University said "This work offers valuable new insight into the way in which long-term cannabinoid exposure negatively impacts on the brain. Understanding these mechanisms is central to understanding how long-term cannabinoid exposure increases the risk of developing mental health issues and memory problems."
He also highlighted the relevance of the work to those using cannabinoid-based therapies to treat medical conditions.
"Cannabis-based therapies can be very effective at treating the symptoms of chronic diseases such as epilepsy and multiple sclerosis, and dramatically increase the quality of life for people living with these conditions. We need to understand the side effects that these people may experience so that we can develop new interventions to minimise these side effects."
Professor Ana Sebastiao, lead researcher at the University of Lisbon, said: "Importantly, our work clearly shows that prolonged cannabinoid intake, when not used for medical reasons, does have a negative impact in brain function and memory. It is important to understand that the same medicine may re-establish an equilibrium under certain diseased conditions, such as in epilepsy or MS, but could cause marked imbalances in healthy individuals. "As for all medicines, cannabinoid based therapies have not only beneficial disease-related actions, but also negative side effects. It is for the medical doctor to weight the advantages of the therapy, taking into consideration quality of life and diseases progression, against the potential side effects."
The research was published in the Journal of Neurochemistry and was conducted as part of the European Commission Horizon 2020 funded SynaNET project.
Story Source:
Materials provided by Lancaster University. Note: Content may be edited for style and length.
Journal Reference:
Francisco M Mouro, Joaquim A Ribeiro, Ana M Sebastião, Neil Dawson. Chronic, intermittent treatment with a cannabinoid receptor agonist impairs recognition memory and brain network functional connectivity. Journal of Neurochemistry, 2018; DOI: 10.1111/jnc.14549
Cite This Page:
Lancaster University. "How cannabis and cannabis-based drugs harm your brain." ScienceDaily. ScienceDaily, 23 July 2018. <www.sciencedaily.com/releases/2018/07/180723132251.htm>.
Houseplants could one day monitor home health
Incorporating plant 'canaries' into our homes is on the horizon
Date: July 20, 2018 Source: University of Tennessee Institute of Agriculture Summary: A student from two unrelated disciplines -- plant sciences and architectural design -- explore the future of houseplants as aesthetically pleasing and functional sirens of home health. Their idea is to genetically engineer house plants to serve as subtle alarms that something is amiss in our home and office environments.
These are perspective images of a conceptual phytosensor (plant) wall. Shown left is the lighted room, and shown right is the darkened room under sense-and-report photonic conditions. The glass partition (inset on left) concentrates HVAC return air across fungal VOC-sensing houseplants. The inset image on the right shows an engineered Nicotiana plant for constitutive expression of GFP yielding green fluorescence under built-in blue or UV lights next to a wild type red fluorescent plant under the same conditions.
Credit: Photo (inset, right) by Francisco Palacios. Design renderings by Susan G. Stewart and Rana Abudayyeh.
In a perspective published in the July 20 issue of Science, Neal Stewart and his University of Tennessee coauthors explore the future of houseplants as aesthetically pleasing and functional sirens of home health.
The idea is to genetically engineer house plants to serve as subtle alarms that something is amiss in our home and office environments. Stewart, a professor of plant sciences in the UT Herbert College of Agriculture -- who also holds the endowed Racheff Chair of Excellence in Plant Molecular Genetics -- came up with the idea during conversations with his wife, Susan, and Rana Abudayyeh, an assistant professor in the UT College of Architecture and Design's School of Interior Architecture. Both Susan Stewart and Abudayyeh are coauthors of the article. Susan Stewart recently graduated from the school as a non-traditional, re-entry student, and Abudayyeh was among her professors.
This is not the first time that plants have been proposed as biosensors. The authors point out that to date several environmentally relevant phytosensors have been designed by using biotechnology. In fact, what was once known as genetic engineering has grown into a whole field of study called synthetic biology, which is the design and construction of new biological entities or systems.
Synthetic biology is a valuable tool for agricultural production, allowing farmers to grow plants designed to resist drought or certain pests, and Neal Stewart has authored or coauthored several studies involving the engineering of plants to react to certain conditions, like the presence of too much or too little nitrogen. Such plants "glow" when viewed with specifically designed filters. Once this technology is commercialized, it may allow farmers of the future to adjust their management plans accordingly.
What is new, and which the authors discuss in the Science article, is the concept of applying synthetic biology to houseplants beyond aesthetic reasons, like larger blooms or variegated foliage. "Houseplants are ubiquitous in our home environments," says Neal Stewart. "Through the tools of synthetic biology it's possible for us to engineer houseplants that can serve as architectural design elements that are both pleasing to our senses and that function as early sensors of environmental agents that could harm our health, like mold, radon gas or high concentrations of volatile organic compounds." Stewart explains that plant biosensors could be designed to react to harmful agents in any number of ways, such as gradually changing the color of their foliage or through the use of fluorescence. "They can do a lot more than just sit there and look pretty," he says. "They could alert us to the presence of hazards in our environment."
The authors postulate that dense populations of biosensors would be needed, so architectural design elements like "plant walls" might best serve as environmental monitors while also serving our innate need to connect with nature even while indoors.
"Biophlic design builds on our innate affiliation with nature, so integrating biophlic elements within the interior volume carries rich implications spatially and experientially," says Abudayyeh. "Building responsive capabilities into interior plants is revolutionary. It allows biophlic elements within space to assume a more integral role in the space, actively contributing to the well-being of the occupant holistically."
While the Science article presents the concept, Neal Stewart and Abudayyeh have plans to bring their ideas from the lab to future blueprints and ultimately to our homes, schools, hospitals and offices. Neal Stewart and Abudayyeh have already collaborated on a grant proposal, and they plan to pursue additional projects in the future.
"Our work should result in an interior environment that is more responsive to overall health and well-being of its occupants while continuing to provide the benefits plants bring to people every day," says Abudayyeh. "I'm thrilled that my students will be part of this breakthrough research as they integrate this kind of innovation into designing interior spaces. "This long-term project is a unique and intriguing partnership between two seemingly unrelated disciplines, interior architecture and plant sciences," Abudayyeh continues.
As the authors indicate in the Science article, the potential benefits to society of such collaborative research are enormous.
Story Source:
Materials provided by University of Tennessee Institute of Agriculture. Original written by Patricia McDaniels. Note: Content may be edited for style and length.
Journal Reference:
C. Neal Stewart, Rana K. Abudayyeh, Susan G. Stewart. Houseplants as home health monitors. Science, 2018; 361 (6399): 229 DOI: 10.1126/science.aau2560
Cite This Page:
University of Tennessee Institute of Agriculture. "Houseplants could one day monitor home health: Incorporating plant 'canaries' into our homes is on the horizon." ScienceDaily. ScienceDaily, 20 July 2018. <www.sciencedaily.com/releases/2018/07/180720112829.htm>.
Complementary medicine for cancer can decrease survival
Date: July 19, 2018 Source: Yale University Summary: People who received complementary therapy for curable cancers were more likely to refuse at least one component of their conventional cancer treatment, and were more likely to die as a result, according to researchers.
People who received complementary therapy for curable cancers were more likely to refuse at least one component of their conventional cancer treatment, and were more likely to die as a result, according to researchers from Yale Cancer Center and the Cancer Outcomes, Public Policy and Effectiveness Research Center (COPPER) at Yale School of Medicine. The findings were reported today online in JAMA Oncology.
Use of complementary medicine -- medical therapies that fall beyond the scope of scientific medicine -- is growing in the United States and often used by patients with cancer. Although many patients believe that a combination of complementary medicine and conventional cancer treatment will provide the greatest chance at a cure, there is limited research evaluating the effectiveness of complementary medicines. It is also unknown whether patients who use complementary medicines use them to improve their response to conventional medical therapies, or use them in lieu of recommended conventional therapies.
"Past research into why patients use non-medical complementary treatments has shown the majority of cancer patients who use complementary medicines believe their use will result in improved survival," said the study's senior author, James Yu, M.D., associate professor of therapeutic radiology at Yale Cancer Center. "We became interested in this topic after we reviewed the literature, and found that there was scant evidence to support this belief."
To investigate complementary medicine use and its impact on survival and treatment adherence, the researchers studied 1,290 patients with breast, prostate, lung, or colorectal cancer in the National Cancer Database (NCDB) -- a joint project of the Commission on Cancer of the American College of Surgeons and the American Cancer Society. The NCDB represents approximately 70% of newly diagnosed cancers nationwide. Researchers compared 258 patients who used complementary medicine to 1,032 who did not.
The researchers studied de-identified patients diagnosed over a 10-year period, from 2004 to 2013. By collecting the outcomes of patients who received complementary medicine in addition to conventional cancer treatments, they found a greater risk of death. Interestingly, they noted, despite having received some conventional cancer therapy, these patients were more likely to refuse other aspects of recommended care like chemotherapy, surgery, radiation and/or hormone therapy. The researchers concluded patients who chose to use complementary medicines as cancer treatment, were more likely to refuse other conventional cancer treatments and as a result, had a higher risk of death than those who used no complementary medicine.
"The fact that complementary medicine use is associated with higher refusal of proven cancer treatments as well as increased risk of death should give providers and patients pause," said lead author Skyler Johnson, M.D., chief resident in radiation oncology at Yale School of Medicine. "Unfortunately, there is a great deal of confusion about the role of complementary therapies. Although they may be used to support patients experiencing symptoms from cancer treatment, it looks as though they are either being marketed or understood to be effective cancer treatments."
Cary Gross, M.D., co-author of the study, called for further research, "The sources of misinformation need to be better understood, so that patients aren't being sold a false bill of goods."
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Materials provided by Yale University. Note: Content may be edited for style and length.
Journal Reference:
Skyler B. Johnson, Henry S. Park, Cary P. Gross, James B. Yu. Complementary Medicine, Refusal of Conventional Cancer Therapy, and Survival Among Patients With Curable Cancers. JAMA Oncology, 2018; DOI: 10.1001/jamaoncol.2018.2487
Cite This Page:
Yale University. "Complementary medicine for cancer can decrease survival." ScienceDaily. ScienceDaily, 19 July 2018. <www.sciencedaily.com/releases/2018/07/180719142001.htm>.
High fruit and vegetable consumption may reduce risk of breast cancer
Date:July 19, 2018 Source: Harvard T.H. Chan School of Public Health Summary: Women who eat a high amount of fruits and vegetables each day may have a lower risk of breast cancer, especially of aggressive tumors, than those who eat fewer fruits and vegetables, according to a new study.
Women who eat a high amount of fruits and vegetables each day may have a lower risk of breast cancer, especially of aggressive tumors, than those who eat fewer fruits and vegetables, according to a new study led by researchers from Harvard T.H. Chan School of Public Health. In their findings, cruciferous vegetables such as broccoli, and yellow and orange vegetables, had a particularly significant association with lower breast cancer risk.
"Although prior studies have suggested an association, they have been limited in power, particularly for specific fruits and vegetables and aggressive subtypes of breast cancer," said first author Maryam Farvid, research scientist in the Department of Nutrition. "This research provides the most complete picture of the importance of consuming high amounts of fruit and vegetables for breast cancer prevention."
The study was published online July 6, 2018 in the International Journal of Cancer.
The researchers analyzed diet questionnaires submitted every four years by participants in the Nurses' Health Study (88,301 women, starting in 1980) and the Nurses' Health Study II (93,844 women, starting in 1991). Data on other potential breast cancer risk factors such as age, weight, smoking status, and family cancer history were taken from biennial questionnaires.
They found that women who ate more than 5.5 servings of fruits and vegetables each day had an 11% lower risk of breast cancer than those who ate 2.5 or fewer servings. (A serving is defined as one cup of raw leafy vegetables, half a cup of raw or cooked vegetables, or half a cup of chopped or cooked fruits.)
To find out whether the benefits of fruit and vegetable consumption differed among various types of breast cancers, the researchers conducted an analysis by tumor hormone receptor status and molecular subtype. They found that higher consumption of fruits and vegetables was particularly associated with lower risk of more aggressive tumors including ER-negative, HER2-enriched, and basal-like tumors.
Previous work by this research group linked reduced breast cancer risk with higher fiber intake, but the benefits of fruits and vegetables found in this study appear to be independent of their fiber content, according to the researchers. This suggests that other constituents of these foods, such as antioxidants and other micronutrients, may also be important in reducing breast cancer risk.
"While a diet with lots of fruits and vegetables is associated with many other health benefits, our results may provide further impetus for women to increase their intake of fruits and vegetables," said senior author Heather Eliassen, associate professor at Harvard Medical School and Harvard Chan School and associate epidemiologist at Brigham and Women's Hospital.
Other Harvard Chan authors included Bernard Rosner, Rulla Tamimi and Walter Willett.
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Materials provided by Harvard T.H. Chan School of Public Health. Note: Content may be edited for style and length.
Journal Reference:
Maryam S. Farvid, Wendy Y. Chen, Bernard A. Rosner, Rulla M. Tamimi, Walter C. Willett, A. Heather Eliassen. Fruit and vegetable consumption and breast cancer incidence: Repeated measures over 30 years of follow-up. International Journal of Cancer, 2018; DOI: 10.1002/ijc.31653
Cite This Page:
Harvard T.H. Chan School of Public Health. "High fruit and vegetable consumption may reduce risk of breast cancer." ScienceDaily. ScienceDaily, 19 July 2018. <www.sciencedaily.com/releases/2018/07/180719101250.htm>.
Does biodiversity loss leads to an increased disease risk?
Date: July 18, 2018 Source: The University of Montana Summary: Biodiversity is disappearing at an alarming rate as infectious diseases increasingly spill over from wildlife to humans. Disease ecologists fervently debate whether biodiversity loss leads to an increased disease risk. Now, a new study offers some answers.
UM population and disease ecology Assistant Professor Andrea Luis reads the eartag of a deer mouse as part of a hantavirus study.
Credit: Angela Luis
Biodiversity is disappearing at an alarming rate as infectious diseases increasingly spill over from wildlife to humans. Disease ecologists fervently debate whether biodiversity loss leads to an increased disease risk. Now, a University of Montana researcher has published a new study with some answers.
UM Assistant Professor Angela Luis shows for the first time that species diversity can have both positive and negative influences on disease transmission in the same host-pathogen system at the same time in her article published in the Proceedings of the National Academy of Sciences.
For a number of species, a more diverse community decreases infection risk, termed "the dilution effect," because biodiversity dilutes infection. If this is a widespread phenomenon, then preserving biodiversity is a win-win for both animal conservation and human health.
However, a debate rages about how general this phenomenon is since, for some systems, a more diverse community increases disease risk, termed the "amplification" effect. For other systems, biodiversity has no consistent effect, leaving its relationship to disease unidentified.
In the latest issue of PNAS, Luis, a disease ecologist, shows that the Sin Nombre hantavirus among rodents displays a significant dilution effect. Areas with a more diverse rodent community have lower hantavirus prevalence among deer mice, which are the main reservoir for the disease. When the virus spills over into humans, it causes hantavirus pulmonary syndrome, which has infected more than 700 people and killed about 1 in 3 since its discovery in 1993.
Luis' study shows deer mouse density causes the dilution effect. In more diverse communities -- with more rodent species present in the same area -- there tend to be fewer mice due to competition, and disease spread slows down.
However, for a given mouse density, as rodent species diversity increases, infection spreads faster in a "component amplification effect" as mice become stressed and their immunity decreases. Therefore both dilution and amplification occur in the same system at the same time.
It's not as simple as more biodiversity means less disease.
"It's been wild to see the debate among disease ecologists in the literature and at conferences. It has been heated at times," Luis said. "Although this study doesn't resolve the debate, it provides an interesting perspective -- the inconsistent findings of whether diversity increases or decreases disease risk may be resolved by delving into the different mechanisms determining disease transmission."
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Materials provided by The University of Montana. Note: Content may be edited for style and length.
Journal Reference:
Angela D. Luis, Amy J. Kuenzi, James N. Mills. Species diversity concurrently dilutes and amplifies transmission in a zoonotic host–pathogen system through competing mechanisms. Proceedings of the National Academy of Sciences, 2018; 201807106 DOI: 10.1073/pnas.1807106115
Cite This Page:
The University of Montana. "Does biodiversity loss leads to an increased disease risk?." ScienceDaily. ScienceDaily, 18 July 2018. <www.sciencedaily.com/releases/2018/07/180718152240.htm>.
How cannabis affects appetite: Brain changes
Date: July 17, 2018 Source: Society for the Study of Ingestive Behavior Summary: New research on how cannabis use alters eating behavior could lead to treatments for appetite loss in chronic illness, according to experts. Using a new procedure to dose lab rats with cannabis vapor, the researchers found how the drug triggers hunger hormones. They also identified specific brain regions that shift to 'hungry' mode while under the influence.
New research on how cannabis use alters eating behavior could lead to treatments for appetite loss in chronic illness, according to experts at Washington State University. Using a new procedure to dose lab rats with cannabis vapor, the researchers found how the drug triggers hunger hormones. They also identified specific brain regions that shift to 'hungry' mode while under the influence, according to a report they shared this week at the Society for the Study of Ingestive Behavior, an international meeting of scientific experts on eating.
"We all know cannabis use affects appetite, but until recently we've actually understood very little about how or why," explained Jon Davis, Ph.D., researcher in the Department of Integrative Physiology and Neurosciences at Washington State. "By studying exposure to cannabis plant matter, the most widely consumed form, we're finding genetic and physiological events in the body that allow cannabis to turn eating behavior on or off."
A recent wave of cannabis legalization for both medical and recreational purposes has stimulated research on its therapeutic potential. A family of compounds called cannabinoids, particularly delta-9 tetrahydrocannabinol (THC), are responsible for its psychological effects. The ability of THC to stimulate appetite is valuable since many illnesses cause extreme appetite loss which reduces quality of life and slows recovery.
For these new studies the scientists designed a vapor exposure system to mimic how people often consume cannabis. This allowed precise control of dosage while rats' meals were closely monitored throughout the day. Brief exposure to cannabis vapor stimulated a meal even when rats had recently eaten, suggesting that inhaling cannabis tricks appetite circuits in the brain into hunger mode.
"We found that cannabis exposure caused more frequent, small meals," stated Davis. "But there's a delay before it takes effect." That delay provided a clue to how the drug may act. Ordinarily, when the stomach is empty it releases a hormone called ghrelin, a message to the brain that it's time to look for food. The researchers found that the cannabis dose triggered a ghrelin surge. When they gave a second drug which prevented the ghrelin surge, cannabis no longer triggered eating. They also found changes in how the brain responds to the message. In small region of the hypothalamus responsible for sensing ghrelin, cannabis changed the genetic activity of brain cells that respond to the hormone.
The researchers are optimistic that deciphering that ways cannabis acts in the body to alter appetite can lead to new treatments for illness-induced anorexia. Severe appetite loss is a common symptom of many chronic illnesses, and is especially problematic in cancer, HIV/AIDS, heart disease, and some metabolic disorders. A targeted treatment that offers the beneficial effects on appetite without the broader effects on the mind and body could increase quality of life and speed recovery.
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Materials provided by Society for the Study of Ingestive Behavior. Note: Content may be edited for style and length.
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Society for the Study of Ingestive Behavior. "How cannabis affects appetite: Brain changes." ScienceDaily. ScienceDaily, 17 July 2018. <www.sciencedaily.com/releases/2018/07/180717094747.htm>.
Anti-obesity drug derived from chili peppers shows promise in animal trials
Date: July 17, 2018 Source: Society for the Study of Ingestive Behavior Summary: A novel drug based on capsaicin, the compound that gives chili peppers their spicy burn, caused long term weight loss and improved metabolic health in mice eating a high fat diet. The drug, Metabocin, was designed to slowly release capsaicin throughout the day so it can exert its anti-obesity effect without producing inflammation or adverse side effects.
A novel drug based on capsaicin, the compound that gives chili peppers their spicy burn, caused long term weight loss and improved metabolic health in mice eating a high fat diet, in new studies from the University of Wyoming School of Pharmacy. The drug, Metabocin, was designed to slowly release capsaicin throughout the day so it can exert its anti-obesity effect without producing inflammation or adverse side effects.
"We observed marked improvements in blood sugar and cholesterol levels, insulin response, and symptoms of fatty liver disease," reported Dr. Baskaran Thyagarajan, lead investigator, describing how Metabocin reversed many damaging effects of the high fat diet. He presented the results this week at the annual meeting of the Society for the Study of Ingestive Behavior, the leading international conference of experts on food and fluid intake.
The research team developed Metabocin, which can be taken orally, to target receptors called TRPV1 (transient receptor potential vanilloid subfamily 1) that are found in high numbers in fat cells. Stimulating the TRPV1 receptors causes white fat cells to start burning energy instead of storing it, which, in theory, should cause weight loss. An important question for the researchers was whether the drug remains effective when used long term, and whether adverse effects would outweigh its benefits. The mice in this experiment remained on the drug for 8 months, maintaining the weight loss with no evidence of safety problems. Additional ongoing experiments will see how long that can be maintained.
"It proved safe and was well tolerated by the mice," Thyagarajan concluded. "Developing Metabocin as a potent anti-obesity treatment shows promise as part of a robust strategy for helping people struggling with obesity."
Although these results may give some people the idea to eat more spicy food to lose weight, that would not work as intended. Most of the capsaicin in spicy food is not well absorbed into the body so it would not produce these effects. The researchers specifically modified the capsaicin in Metabocin for proper absorption and sustained release.
Obesity is a growing public health concern, resulting in metabolic diseases including type 2 diabetes, hypertension, atherosclerosis and heart diseases. Currently one in three individuals world-wide is either overweight or obese. Exercise and diet are the standard recommendation, but those are difficult for most people to maintain in the long term, and rebound weight gain usually occurs. The Wyoming researchers advocated for continuing to pursue medical options that stay effective in the long term to counter obesity and its metabolic impacts, to assist people seeking to maintain a healthier weight.
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Materials provided by Society for the Study of Ingestive Behavior. Note: Content may be edited for style and length.
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Society for the Study of Ingestive Behavior. "Anti-obesity drug derived from chili peppers shows promise in animal trials." ScienceDaily. ScienceDaily, 17 July 2018. <www.sciencedaily.com/releases/2018/07/180717094735.htm>.
Vitamin D no defense against dementia
Date: July 10, 2018
Source: University of Adelaide
Summary:
New research has shown that vitamin D (also commonly known as the sunshine vitamin) is unlikely to protect individuals from multiple sclerosis, Parkinson's disease, Alzheimer's disease or other brain-related disorders.
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Certain antibodies against a sugar are associated with malaria protection
New technique used to analyse levels and type of antibodies to a carbohydrate expressed by most living beings
Date:July 9, 2018 Source: Barcelona Institute for Global Health (ISGlobal) Summary: Certain type of antibodies against alpha-Gal- a carbohydrate expressed by many organisms including the malaria parasite- could protect against malaria, according to a new study. The resultsindicate that a-Gal is an interesting candidate to include in future vaccines against malaria and other infectious diseases.
These are alpha-Gal antibody levels at various ages.
Credit: Adapted from Aguilar R et al. 2018
Certain type of antibodies against α-Gal- a carbohydrate expressed by many organisms including the malaria parasite- could protect against malaria, according to a new study led by ISGlobal, an institution supported by "la Caixa" Foundation. The results, published in Scientific Reports, indicate that a-Gal is an interesting candidate to include in future vaccines against malaria and other infectious diseases.
The magnitude and type of immune response against the malaria parasite is key in controlling the disease. To date, most studies have focused on the antibody response to parasite proteins. However, sugars (or glycans) expressed on the surface of the parasite could also trigger an immune response.
Alpha-gal is a particularly interesting glycan: it is expressed by practically all organisms on the evolutionary scale, from bacteria in out gut, to pathogenic bacteria such as Salmonella, protozoan parasites such as P. falciparum (that causes malaria) or mammals such as cows. Only humans, apes and old-world monkeys lack the enzyme to synthesize it and generate a strong immune response against it. Recent studies suggest that antibodies to α-Gal could protect against malaria.
In this study, the teams led by Luis Izquierdo and Carlota Dobaño, ISGlobal researchers, joined forces to assess the magnitude and type of antibody responses against α-Gal in infants and children from Mozambique (a low malaria transmission region) and Ghana (a high transmission region). They used a technique recently developed by Dobaño's group that allowed measuring for the first time different subclasses of antibodies against this and other parasite antigens in a single reaction and from one drop of blood.
"The relevance of this study is that it provides new information on a response (anti α-Gal) that plays a potential protective role against a variety of infectious diseases, not only malaria," explains Dobaño.
The results show that the levels of different α-Gal antibodies vary according to age and are higher in low malaria transmission zones. A significant increase in IgM ?-Gal antibodies was observed in the initial months of life, while IgG antibodies increased later in life. Importantly, an IgM response was associated with protection against clinical malaria, especially in the first months of life, while total IgG were associated with malaria risk.
"It would be really interesting to identify the specific α-Gal glycan expressed by the malaria parasite, and to confirm the potential association between certain IgG subclasses and protection," says Izquierdo. "In any case, these results confirm that α-Gal could be a promising molecule to include in future malaria vaccines," he adds.
Story Source:
Materials provided by Barcelona Institute for Global Health (ISGlobal). Note: Content may be edited for style and length.
Journal Reference:
Ruth Aguilar, Itziar Ubillos, Marta Vidal, Núria Balanza, Núria Crespo, Alfons Jiménez, Augusto Nhabomba, Chenjerai Jairoce, David Dosoo, Ben Gyan, Aintzane Ayestaran, Hèctor Sanz, Joseph J. Campo, Gloria P. Gómez-Pérez, Luis Izquierdo, Carlota Dobaño. Antibody responses to α-Gal in African children vary with age and site and are associated with malaria protection. Scientific Reports, 2018; 8 (1) DOI: 10.1038/s41598-018-28325-w
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Barcelona Institute for Global Health (ISGlobal). "Certain antibodies against a sugar are associated with malaria protection: New technique used to analyse levels and type of antibodies to a carbohydrate expressed by most living beings." ScienceDaily. ScienceDaily, 9 July 2018. <www.sciencedaily.com/releases/2018/07/180709120130.htm>.
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