Wearing surgical masks in public could help slow COVID-19 pandemic's advance

Surgical masks may help prevent infected people from making others sick with seasonal viruses, including coronaviruses, according to new research that could help settle a fierce debate spanning clinical and cultural norms.

In laboratory experiments, the masks significantly reduced the amounts of various airborne viruses coming from infected patients, measured using the breath-capturing "Gesundheit II machine" developed by Dr. Don Milton, a professor of applied environmental health and a senior author of the study published April 3 in the journal Nature Medicine.

Milton has already conferred with federal and White House health officials on the findings, which closely follow statements this week from the head of the Centers for Disease Control and Prevention saying the agency was reconsidering oft-stated advice that surgical masks aren't a useful precaution outside of medical settings. (The debate takes place at a time when clinicians themselves face dangerously inadequate supplies of masks -- a shortfall other UMD researchers are scrambling to help solve.)

The question of masks has roiled society as well, with some retailers refusing to let employees wear them for fear of sending negative signals to customers, and cases of slurs and even physical attacks in the United States and elsewhere against Asians or Asian Americans who were wearing masks, a measure some consider a necessity during a disease outbreak.

The study, conducted prior to the current pandemic with a student of Milton's colleagues on the Faculty of Medicine at the University of Hong Kong, does not address the question of whether surgical masks protect wearers from infection. It does suggest that masks may limit how much the infected -- who in the case of the novel coronavirus often don't have symptoms -- spread diseases including influenza, rhinoviruses and coronaviruses.

Milton, who runs the Public Health Aerobiology, Virology, and Exhaled Biomarker Laboratory in the School of Public Health, demonstrated in a 2013 study that surgical masks could help limit flu transmission. However, he cautions that the effect may not be as great outside of controlled settings.

Nevertheless, he said, the chance they could help justifies taking a new look at whether all people should be encouraged to wear them when they venture out of their houses to stores or other populated locations during the current COVID-19 lockdown.

"In normal times we'd say that if it wasn't shown statistically significant or the effective in real-world studies, we don't recommend it," he said. "But in the middle of a pandemic, we're desperate. The thinking is that even if it cuts down transmission a little bit, it's worth trying."

Previous studies have shown that coronavirus and other respiratory infections are mostly spread during close contact, which has been interpreted by some infectious disease specialists to mean that the disease could spread only through contact and large droplets, such as from a cough or sneeze -- a message that has often been shared with the public.

"What they don't understand is that is merely a hypothesis," Milton said. The current study (along with earlier ones) shows, by contrast, that tiny, aerosolized droplets can indeed diffuse through the air. That means it may be possible to contract COVID-19 not only by being coughed on, but by simply inhaling the breath of someone nearby who has it, whether they have symptoms or not. Surgical masks, however, catch a lot of the aerosolized virus as it's exhaled, he said.

The study was conducted at the University of Hong Kong as part of the dissertation research of the lead author, Dr. Nancy Leung, who, under the supervision of the co-senior authors Drs. Cowling and Milton, recruited 246 people with suspected respiratory viral infections. Milton's Gesundheit machine compared how much virus they exhaled with and without a surgical mask.

"In 111 people infected by either coronavirus, influenza virus or rhinovirus, masks reduced detectable virus in respiratory droplets and aerosols for seasonal coronaviruses, and in respiratory droplets for influenza virus," Leung said. "In contrast, masks did not reduce the emission of rhinoviruses."

Although the experiment took place before the current pandemic, COVID-19 and seasonal coronaviruses are closely related and may be of similar particle size. The report's other senior author, Professor Benjamin Cowling, division head of epidemiology and biostatistics, School of Public Health, HKUMed, and co-director of the World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, said, "The ability of surgical masks to reduce seasonal coronavirus in respiratory droplets and aerosols implies that such masks can contribute to slowing the spread of (COVID-19) when worn by infected people."

Milton pointed to other measures his research has found is even more effective than masks, such as improving ventilation in public places like grocery stores, or installing UV-C lights near the ceiling that works in conjunction with ceiling fans to pull air upwards and destroy viruses and bacteria.

"Personal protective equipment like N95 masks are not our first line of defense," Milton said. "They are our last desperate thing that we do."

Hong Kong University contributed to this report.

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Story Source:

Materials provided by University of Maryland. Original written by Chris Carroll. Note: Content may be edited for style and length.

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Journal Reference:

1. Nancy H. L. Leung, Daniel K. W. Chu, Eunice Y. C. Shiu, Kwok-Hung Chan, James J. McDevitt, Benien J. P. Hau, Hui-Ling Yen, Yuguo Li, Dennis K. M. Ip, J. S. Malik Peiris, Wing-Hong Seto, Gabriel M. Leung, Donald K. Milton, Benjamin J. Cowling. Respiratory virus shedding in exhaled breath and efficacy of face masks. Nature Medicine, 2020; DOI: 10.1038/s41591-020-0843-2

Biofeedback could help treat a number of conditions Headaches among

Biofeedback could help treat a number of conditions Headaches among

A literature review by a team at the VA Portland Health Care System and Oregon Health & Science University found evidence that biofeedback can be a helpful treatment for several conditions. Studies show that biofeedback can reduce headache pain, improve both urinary and fecal incontinence, and aid in stroke recovery.

Dr. Karli Kondo of the VA Evidence Synthesis Program and OHSU, first author on the study, explained how the research could advance the use of biofeedback: "We are encouraged by the positive findings and the additional findings of potential benefits for a wide range of conditions. Biofeedback is a low-risk, cost-effective intervention. We hope that this report will help to make biofeedback more widely available to veterans across the U.S., and that it will serve as a roadmap for future research in the field."

The results appeared online Aug. 14, 2019, in the Journal of General Internal Medicine.

Biofeedback refers to using instruments to measure and provide real-time feedback on patients' physiological responses. It can help patients learn to control and change those responses. Since biofeedback does not involve medication and is relatively noninvasive compared to other treatments, it could benefit patients with a low risk of any adverse effects, say the researchers.

Biofeedback measures include muscle activity, heart rate, blood pressure, and brainwaves. It is often paired with treatments to change behavior, thoughts, or emotions. For example, using electromyography (EMG) to measure how muscles tighten in response to a medical condition may help patients consciously control those muscles.

Biofeedback increasingly is being used as a complementary or alternative treatment for a wide range of conditions. In 2017, about 70 VA facilities reported offering some form of biofeedback.

However, the evidence on how biofeedback is used and its effectiveness is scattered across studies on the individual conditions. Because of this, the practice is not well-integrated with usual care.

Kondo and colleagues created an "evidence map" to get a high-level overview of the research available on biofeedback. They searched for previously conducted systematic reviews and studies on biofeedback to summarize what has been found so far. In total, the researchers used 16 systematic reviews on the topic.

The review showed clear evidence that biofeedback is effective at reducing headache pain. A variety of biofeedback measures have been used for headache, including EMG, skin temperature, and blood pressure monitoring. These techniques appear to help decrease the frequency, duration, and intensity of both migraine and tension headaches. The largest improvements were in decreasing frequency of headaches. Moderate-confidence evidence shows that biofeedback can also improve secondary outcomes of headache, such as medication use, muscle tension, anxiety, and depression.

Strong evidence also exists showing that biofeedback can help with urinary incontinence for men who have had their prostate removed. In this case, EMG is used to assist with pelvic floor muscle training. Adding biofeedback provides both immediate and long-term improvements beyond those seen with muscle training alone.

The evidence map shows consistent evidence that biofeedback helps with several other conditions, although with fewer trials than were found for headaches or incontinence. EMG biofeedback can help with fecal incontinence in both older people of both sexes and in young women who recently gave birth. Adding biofeedback to therapy for lower-limb activity after stroke also appears to help patients. Stroke therapy can include several different types of biofeedback, such as platforms that measure weight distribution to help with balance, sensors to measure the angle of the joints during walking, and EMG to record muscle activity.

The researchers found studies on biofeedback use for several other conditions, but no compelling evidence that it was effective in those cases. Reviews showed no benefits from biofeedback for urinary incontinence in women or for high blood pressure management. However, the studies covering these conditions were limited. Likewise, the review turned up insufficient evidence for the use of biofeedback for other conditions, such as bruxism (grinding or clenching the teeth, often while sleeping), labor pain, and Reynaud's disease (a condition involving reduced blood flow to the extremities).

The researchers point out that their evidence map, in addition to showing several conditions for which biofeedback has been proven useful, also shows areas of uncertainty where more research is needed. They identified several targets for further research: balance and gait training, fibromyalgia, and intradialytic hypotension (a decrease in blood pressure that can cause a number of symptoms, including nausea, dizziness, and anxiety).

Overall, the evidence map gives a "lay of the land" that shows what evidence exists for using biofeedback to treat medical conditions or symptoms and what research is still needed.

The study was funded by the VA Office of Research and Development Quality Enhancement Research Initiative.

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Materials provided by Veterans Affairs Research Communications. Original written by Tristan Horrom, VA Research Communications. Note: Content may be edited for style and length.

Lower back pain? Self-administered acupressure could help

Pain affected regions

A recent study finds that acupressure, a traditional Chinese medicine technique, can improve chronic pain symptoms in the lower back.

"Acupressure is similar to acupuncture, but instead of needles, pressure is applied with a finger, thumb or device to specific points on the body," says Susan Murphy, ScD, OTR, an associate professor of physical medicine and rehabilitation at Michigan Medicine and lead author of the study.

Murphy says that while acupressure has been previously studied -- and found to be beneficial -- in people with cancer-related or osteoarthritis pain, there are few studies that have examined acupressure in people with back pain.

In the study, published in Pain Medicine, the research team randomly assigned 67 participants with chronic low back pain into three groups: relaxing acupressure, stimulating acupressure or usual care.

"Relaxing acupressure is thought to be effective in reducing insomnia, while stimulating acupressure is thought to be effective in fatigue reduction," Murphy says.

Participants in the acupressure groups were trained to administer acupressure on certain points of the body, and spent between 27 and 30 minutes daily, over the course of six weeks, performing the technique.

Participants in the usual care group were asked to continue whatever treatments they were currently receiving from their care providers to manage their back pain and fatigue.

"Compared to the usual care group, we found that people who performed stimulating acupressure experienced pain and fatigue improvement and those that performed relaxing acupressure felt their pain had improved after six weeks," Murphy says.

"We found no differences among the groups in terms of sleep quality or disability after the six weeks."

Potential treatment option

Murphy notes that chronic pain is difficult to manage and people with the condition tend to have additional symptoms such as fatigue, sleep disturbance and depression.

"Better treatments are needed for chronic pain," Murphy says. "Most treatments offered are medications, which have side effects, and in some cases, may increase the risk of abuse and addiction."

She says this study highlights the benefits of a non-pharmacological treatment option that patients could perform easily on their own and see positive results.

"Although larger studies are needed, acupressure may be a useful pain management strategy given that it is low risk, low cost and easy to administer," Murphy says.

"We also recommend additional studies into the different types of acupressure and how they could more specifically be targeted to patients based on their symptoms."

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Materials provided by Michigan Medicine - University of Michigan. Note: Content may be edited for style and length.

Experts unlock key to photosynthesis, a find that could help us meet food security demands

Green leaf in sunlight

Scientists have solved the structure of one of the key components of photosynthesis, a discovery that could lead to photosynthesis being 'redesigned' to achieve higher yields and meet urgent food security needs.

The study, led by the University of Sheffield and published today in the journal Nature, reveals the structure of cytochrome b6f -- the protein complex that significantly influences plant growth via photosynthesis.

Photosynthesis is the foundation of life on Earth providing the food, oxygen and energy that sustains the biosphere and human civilisation.

Using a high-resolution structural model, the team found that the protein complex provides the electrical connection between the two light-powered chlorophyll-proteins (Photosystems I and II) found in the plant cell chloroplast that convert sunlight into chemical energy.

Lorna Malone, the first author of the study and a PhD student in the University of Sheffield's Department of Molecular Biology and Biotechnology, said: "Our study provides important new insights into how cytochrome b6f utilises the electrical current passing through it to power up a 'proton battery'. This stored energy can then be then used to make ATP, the energy currency of living cells. Ultimately this reaction provides the energy that plants need to turn carbon dioxide into the carbohydrates and biomass that sustain the global food chain."

The high-resolution structural model, determined using single-particle cryo-electron microscopy, reveals new details of the additional role of cytochrome b6f as a sensor to tune photosynthetic efficiency in response to ever-changing environmental conditions. This response mechanism protects the plant from damage during exposure to harsh conditions such as drought or excess light.

Dr Matt Johnson, reader in Biochemistry at the University of Sheffield and one of the supervisors of the study added: "Cytochrome b6f is the beating heart of photosynthesis which plays a crucial role in regulating photosynthetic efficiency.

"Previous studies have shown that by manipulating the levels of this complex we can grow bigger and better plants. With the new insights we have obtained from our structure we can hope to rationally redesign photosynthesis in crop plants to achieve the higher yields we urgently need to sustain a projected global population of 9-10 billion by 2050."

The research was conducted in collaboration with the Astbury Centre for Structural Molecular Biology at the University of Leeds.

Researchers now aim to establish how cytochrome b6f is controlled by a myriad of regulatory proteins and how these regulators affect the function of this complex.