Culture

Hospital privacy curtains may harbor dangerous germs: New study

Arlington, Va., September 27, 2018 - Without timely intervention, privacy curtains in hospitals can become breeding grounds for resistant bacteria, posing a threat to patient safety, according to new research published in the American Journal of Infection Control (AJIC), the journal of the Association for Professionals in Infection Control and Epidemiology (APIC).

The longitudinal, prospective, pilot study tracked the contamination rate of ten freshly laundered privacy curtains in the Regional Burns/Plastics Unit of the Health Services Center in Winnipeg, Canada. While the curtains had minimal contamination when they were first hung, the curtains that were hung in patient rooms became increasingly contaminated over time - and by day 14, 87.5 percent of the curtains tested positive for methicillin-resistant Staphylococcus aureus (MRSA), a pathogen associated with significant morbidity and mortality. In contrast, control curtains that were not placed in patient rooms stayed clean the entire 21 days.

None of the rooms where the curtains were placed were occupied by patients with MRSA. Four curtains were placed in a four-bed room; four were placed in two double rooms; and two controls were placed in areas without direct patient or caregiver contact. Researchers took samples from areas where people hold curtains, suggesting that the increasing contamination resulted from direct contact.

"We know that privacy curtains pose a high risk for cross-contamination because they are frequently touched but infrequently changed," said Kevin Shek, BSc, the study's lead author in the article. "The high rate of contamination that we saw by the fourteenth day may represent an opportune time to intervene, either by cleaning or replacing the curtains."

By day 21, almost all curtains exceeded 2.5 CFU/cm, the requirement for food processing equipment cleanliness in some locations, such as the United Kingdom.

"Keeping the patient's environment clean is a critical component in preventing healthcare-associated infections," said 2018 APIC President Janet Haas, PhD, RN, CIC, FSHEA, FAPIC. "Because privacy curtains could be a mode of disease transmission, maintaining a schedule of regular cleaning offers another potential way to protect patients from harm while they are in our care."

The study authors acknowledge the small sample size of this pilot study and recommend additional research to understand the clinical consequences of contaminated curtains.

Credit: 
Elsevier

Trial participation among factors influencing risk of relapse in AYA leukemia patients

Bottom Line: Adolescent and young adult (AYA) patients with acute lymphoblastic leukemia (ALL) were significantly more likely to relapse than pediatric ALL patients, and factors including lower clinical trial enrollment and shorter duration of therapy were associated with relapse.

Journal in Which the Study was Published: Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

Author: Julie A. Wolfson, MD, MSHS, assistant professor and member of the Institute for Cancer Outcomes and Survivorship at the School of Medicine, University of Alabama at Birmingham.

Background: While pediatric cancer patients have experienced dramatic improvement in survival rates, AYA patients have not seen equal improvement, Wolfson explained.

To address this disparity, the National Cancer Institute (NCI) created a special designation for the AYA population and has supported research investigating why these patients often have worse cancer outcomes.

"Patients diagnosed between the ages of 15 and 39 simply have not seen the same improvement as those in other age groups. In this study, we examined factors related to health care delivery and treatment to increase our understanding of why they experience poorer outcomes," Wolfson said.

How the Study Was Conducted: The researchers assembled a retrospective cohort of ALL patients diagnosed between ages 1 and 39 and treated at City of Hope, an NCI-designated Comprehensive Cancer Center, between 1990 and 2010. In all, 91 patients were children (age 1 to 14) and 93 were AYA (age 15 to 39).

The researchers established variables including demographics, insurance status, participation in clinical trials, duration of treatment, and whether the patients had been treated with "pediatric-inspired" or "adult-inspired" regimens. Wolfson explained that whether an AYA patient is treated more like a pediatric patient or more like an adult is often simply determined by the hospital where they receive care. Using Kaplan-Meier survival analysis, the researchers calculated the risk of relapse.

Results: As previous research had indicated, children with ALL had superior relapse-free survival compared with AYAs. Five years after diagnosis, 74 percent of children had not relapsed or died, compared with 29 percent of younger AYAs (ages 15 to 21) and 32 percent of older AYAs (ages 22-39).

Other key findings:

- Forty-eight percent of AYAs suffered a relapse while on therapy, compared with 17 percent of children. Among these patients, Wolfson said the strongest predictors of relapse were race (non-white patients were twice as likely to relapse) and enrollment in clinical trials (those who were not enrolled were 2.6 times more likely to relapse.)

- After completion of therapy, 47 percent of AYAs suffered a relapse, compared with 13 percent of children. Among these patients, Wolfson said the most significant factor was the duration of treatment, both in the consolidation and maintenance phases. For each additional month of maintenance therapy, there was a 30 percent lower risk of relapse.

Author's Comments: Wolfson said the study adds to evidence that AYA patients should be encouraged to participate in clinical trials. She explained that many trials are designed for either pediatric patients or adult patients, and the cancer center an AYA patient chooses may not have an appropriate clinical trial. Ideally, an AYA patient diagnosed with ALL should be counseled on whether any clinical trial is available, whether at the hospital where they first seek treatment or at another center.

Wolfson added that clinical trial participation confers multiple benefits. "It is possible that patients sometimes benefit from being enrolled on a clinical trial not only because the therapy itself is providing a benefit, but also because it is a protocolized, regulated approach that requires patients to stay on course and not take breaks," she said.

Wolfson said a broad range of factors may affect the duration of treatment. For example, the AYA population is more likely to be uninsured or underinsured, which can make them more likely to stop treatment or miss appointments.

Wolfson said research is ongoing to identify ways to get more AYA patients into clinical trials. She said the NCI has been working on changing age limits in studies, for example, lowering age ranges of adult studies and raising age limits on pediatric studies so that AYAs would be more likely to match study criteria.

Credit: 
American Association for Cancer Research

Large stretches of coral reefs can be rehabilitated

image: Coral reef grow over restoration structures in Indonesia.

Image: 
Christine Sur/UC Davis

Even after being severely damaged by blast fishing and coral mining, coral reefs can be rehabilitated over large scales using a relatively inexpensive technique, according to a study led by the University of California, Davis, in partnership with Mars Symbioscience.

For the study, published this week in the journal Restoration Ecology, researchers installed 11,000 small, hexagonal structures called "spiders" across 5 acres of reef in the center of Indonesia's Coral Triangle. Coral diversity is the highest on Earth in that region but is threatened by human activity, including overfishing, pollution and climate change.

Between 2013 and 2015, researchers attached coral fragments to the structures, which also stabilized rubble and allowed for water to flow through freely.

A CORAL SUCCESS STORY

Live coral cover on the structures increased from less than 10 percent to more than 60 percent. This was more than what was reported for reefs in many other areas of the Coral Triangle, at a cost of about $25 per square meter.

"Coral reef rehabilitation and restoration efforts are rapidly increasing around the world, but there are few large-scale examples of successful projects," said corresponding author Christine Sur, who was a UC Davis graduate student at the time of the study. "Our study demonstrates a cost-effective, scalable method that can inform other coral reef restoration efforts aimed at reducing the global decline of these valuable and unique ecosystems."

Of particular surprise, while massive coral bleaching decimated other parts of the world between 2014 and 2016, bleaching in the rehabilitation area was less than 5 percent, despite warm water conditions known to stress corals.

A SCIENTIST'S LEGACY

The study is one of the last publications led by Susan Williams, a professor and marine biologist with the UC Davis Bodega Marine Laboratory and Department of Evolution and Ecology who passed away in April 2018.

"Collaboration played a key role in the study's outcome," said corresponding author Jordan Hollarsmith, a doctoral candidate in the UC Davis Graduate Group in Ecology at Bodega Marine Laboratory. "Dr. Williams' dedication to building true partnerships between industry, local scientists and the people who live by the reefs she worked to rebuild was critical to this project's success."

Mars Symbioscience, a business segment of Mars, Incorporated, initiated the project in 2013 in collaboration with local residents on the islands.

"This research is an important step in demonstrating how coral can be restored to a higher degree of cover quite quickly and at a relatively low cost," said Frank Mars, vice president of Mars Sustainable Solutions. "Healthy coral reef ecosystems provide natural coastal protection and are the foundation for many local fisheries, as well as jobs for tourism. They also play a critical role in the Mars supply chain as they provide food security and work for the families and communities we rely on to grow the raw materials we use in our brands around the world. For Mars, helping restore coral reefs is not only a business issue, it's also the right thing to do to ensure the planet, people, and communities that rely on them are healthy and thriving."

BUYING TIME TO REVERSE THE DECLINE

Coral reefs are declining worldwide. Reversing their decline will require fully addressing climate change and other human impacts, the study said. For instance, illegal fishing, lack of island sanitation systems, threatened seagrass communities and marine debris such as plastic pollution are common issues in Indonesia and many tropical environments. People living in small island communities in this region also have few alternatives to fishing livelihoods and often lack access to education about the ocean environment.

In the meantime, the "spider" technique and restoration projects offer a way to rehabilitate large swaths of coral reefs and the communities that depend on them, giving the reefs a chance to adapt or acclimate to worsening ocean conditions.

Credit: 
University of California - Davis

Decades in the making -- A breakthrough in the hunt for a vaccine against foal pneumonia

A vaccine against deadly foal pneumonia might finally be within reach, thanks to Morris Animal Foundation-funded research conducted at two major universities. The breakthrough could potentially save the lives of thousands of foals every year.

"After many decades of efforts, our research, funded by Morris Animal Foundation, has led to the first effective vaccine protecting foals against infection with R. equi., considered the most common and important form of pneumonia in foals older than a few weeks of age," said Dr. Noah Cohen, one of the senior authors of the PLOS Pathogens paper describing the vaccine trail, and the Patsy Link Chair in Equine Research at Texas A&M University. Researchers at Harvard Medical School also were part of the research team.

In addition to causing severe, insidiously progressive pneumonia, infection with Rhodococcus equi can affect other organs in the body, such as bones (including the spine), abdominal lymph nodes, eyes, joints and brain. Fatality rates range from 20 percent to 40 percent of infected foals. There currently are no licensed vaccines to protect against foal pneumonia, creating a critical need for development of an effective vaccine.

For the vaccine trial, Dr. Cohen's team first investigated if vaccinating pregnant mares at three weeks and six weeks prior to birth of their foals protected their newborns against foal pneumonia. The team found antibodies that ward off pneumonia were transferred to the foals via the mares' colostrum, which was critical to establish as horses lack the ability to transfer antibodies through the placenta. Most importantly, those antibodies were able to protect almost all the foals born to vaccinated mares from contracting pneumonia.

Next, the team conducted a small, randomized, controlled study of nine foals with R. equi. Five foals were given serum with high levels of antibodies against R. equi and four were not. All five foals receiving the hyperimmune serum were protected against R. equi pneumonia whereas the foals that received standard plasma all developed pneumonia. Further safety testing is ongoing, but these early results appear to support the safe and effective use of this novel foal vaccine strategy against pneumonia. Moreover, it suggests that immunizing donor horses with this vaccine could be used to produce plasma with which foals could be transfused to prevent R. equi pneumonia.

Pneumonia caused by R. equi, which often clusters by farms, is found on all continents except Antarctica. Some farms experience problems recurrently and other farms sporadically or not at all. Despite effective antibiotic therapies, the incidence of this disease remains high, and many affected foals die. At farms that have problems with this disease, an average of 15 percent to 20 percent of foals develop pneumonia in a given year.

In addition to protecting foals against pneumonia caused by R. equi, Dr. Cohen said the new vaccine has the potential to protect against other diseases, including sepsis, the leading cause of death for foals in the first few weeks of life. Other potential disease targets for the vaccine include bacterial infections such as Streptococcus equi subspecies equi, the cause of the ancient and prevalent disease known as strangles.

"Developing a vaccine to protect foals against pneumonia has long been a priority at Morris Animal Foundation and of the equine researchers we support," said Dr. Kelly Diehl, Interim Vice President of Scientific Programs at Morris Animal Foundation. "We have invested more than $2 million to help fight this disease. Dr. Cohen's team's findings are groundbreaking and have the potential to change how we manage this disease going forward, saving the lives of young horses around the world."

Credit: 
Morris Animal Foundation

Predictable, preventable and deadly: Carbon monoxide poisonings after storms

image: Fred Henretig, MD, is an emergency medicine physician and toxicologist at the Poison Control Center at Children's Hospital of Philadelphia.

Image: 
Children's Hospital of Philadelphia

Severe weather events, such as summer hurricanes, tornadoes, and winter snow storms often result in widespread and prolonged power outages, interrupting essential household functions, including home heating. Power losses may also compromise food storage and home cooling devices. In such a scenario, people may turn to dangerous remedies to compensate for lost electrical power.

An editorial article in the October issue of the American Journal of Public Health addresses the threat of carbon monoxide (CO) poisoning.

"Unfortunately, poison control centers continue to see surges in generator-associated carbon monoxide poisonings during and after major storms, despite mandated warning labels and public health advisories," said the article's author, Fred Henretig, MD, emergency medicine physician and toxicologist at the Poison Control Center at Children's Hospital of Philadelphia. "In many instances of CO poisoning, tragedies result - whole families are poisoned, some fatally."

CO is often called the "silent killer" because it is an odorless, tasteless, colorless toxic gas. CO is made when any appliance that burns wood or fuel (oil, gas, propane, kerosene, coal) is malfunctioning or poorly vented. Early symptoms of CO poisoning are often mistaken for those of the flu and include headache, nausea, sleepiness, dizziness, and confusion. In severe cases CO can cause coma, heart attack, and death. Be suspicious that symptoms may be from CO if they occur shortly after using a furnace or generator, if multiple family members become sick at the same time, or if symptoms improve when outside of a home or building. Babies, children and older adults are particularly susceptible to CO poisoning.

"At toxic levels, CO is a frequent cause of poisoning morbidity and death in the U.S., resulting in more that 50,000 emergency room visits each year," added Henretig.

There are ways to make sure that CO does not cause problems in the home:

a) Make sure that all furnaces, chimneys, wood stoves, and heaters are checked regularly and are in good condition.

b) Never use barbecue grills or gasoline-powered equipment indoors or in a garage.

c) During power outages, gasoline-powered generators should only be used outdoors, away from vents or windows, and at least 25 feet from the house.

d) Don't use gas ovens to heat the home.

e) Be careful to avoid sitting in a car with the engine running if deep snow or mud is blocking the exhaust pipe.

f) Install CO monitors in your home and make sure all monitors have fresh, working batteries.

Credit: 
Children's Hospital of Philadelphia

Limiting children's recreational screen time to less than 2 hours a day linked to better cognition

Only one in 20 US children in the study met the full recommended guidelines on recreational screen time, physical activity and sleep.

Limiting recreational screen time to less than two hours a day, and having sufficient sleep and physical activity is associated with improved cognition, compared with not meeting any recommendations, according to an observational study of more than 4,500 US children aged 8-11 years old published in The Lancet Child & Adolescent Health journal.

Taken individually, limited screen time and improved sleep were associated with the strongest links to improved cognition, while physical activity may be more important for physical health.

However, only one in 20 US children aged between 8-11 years meet the three recommendations advised by the Canadian 24-hour Movement Guidelines to ensure good cognitive development - 9-11 hours of sleep, less than two hours of recreational screen time, and at least an hour of physical activity every day.

The study found that US children spend an average of 3.6 hours a day engaged in recreational screen time.

The authors say that their findings indicate that adhering to the guidelines during childhood and adolescence, particularly for screen time, is important for cognitive development.

"Behaviours and day-to-day activities contribute to brain and cognitive development in children, and physical activity, sedentary behaviour, and sleep might independently and collectively affect cognition," says Dr Jeremy Walsh, CHEO Research Institute, Ottawa, Canada. "Evidence suggests that good sleep and physical activity are associated with improved academic performance, while physical activity is also linked to better reaction time, attention, memory, and inhibition. The link between sedentary behaviours, like recreational screen time, is unclear as this research is in the early stages and it appears to vary depending on the types of screen-based activity." [1]

In the study, data was analysed from 4,520 children from 20 sites across the USA. Children and parents completed questionnaires and measures at the outset of the trial to estimate the child's physical activity, sleep and screen time. Children also completed a cognition test, which assessed language abilities, episodic memory, executive function, attention, working memory and processing speed. The study controlled for household income, parental and child education, ethnicity, pubertal development, body mass index and whether the child had had a traumatic brain injury.

Almost one in three children (29% - 1,330/4,520) met none of the guidelines, 41% (1,845/4,520) met only one, 25% (1,129/4,520) met two, and 5% (216/4,520) met all three recommendations.

Half of the children met the sleep recommendation (51%, 2,303/4,520), 37% (1,655/4,520 children) met the screen time recommendation, and 18% (793/4,520 children) met the physical activity recommendation.

The more individual recommendations the child met, the better their cognition. In addition, meeting only the screen time recommendation or both the screen time and sleep recommendations had the strongest associations with cognitive development.

Although there is substantial evidence for the association between physical activity and cognitive development, in this study meeting the physical activity recommendation alone showed no association with cognition. The authors note this was a surprising finding and may suggest that the measure used may not have been specific enough. They note that physical activity remains the most important behaviour for physical health outcomes, and there is no indication that it negatively affects cognition.

Dr Walsh concludes: "We found that more than two hours of recreational screen time in children was associated with poorer cognitive development. More research into the links between screen time and cognition is now needed, including studying the effect of different types of screen time, whether content is educational or entertainment, and whether it requires focus or involves multitasking. Based on our findings, paediatricians, parents, educators, and policymakers should promote limiting recreational screen time and prioritising healthy sleep routines throughout childhood and adolescence." [1]

The authors note some limitations, including that their study is observational so cannot establish the underlying causes or the direction of the association. The data is also self-reported and could be subject to bias. The questionnaires were only used at the outset of the study, and so do not track how behaviours changed over time so future cycles of the study will need to be analysed to understand trends over time.

Writing in a linked Comment, Dr Eduardo Esteban Bustamante, University of Illinois, USA, says: "Through a stress-adaptation lens, the strong associations between global cognition and meeting the recreational screen time recommendation found by Walsh and colleagues potentially reflect the interruption of the stress-recovery cycle necessary for growth in children who do not meet the recommendation. Each minute spent on screens necessarily displaces a minute from sleep or cognitively challenging activities. In the case of evening screen use, this displacement may also be compounded by impairment of sleep quality. It is tempting to take solace in findings that cognitively challenging screen activities can benefit cognition, but, if given a choice, most children already consistently and predictably choose more stimulating screen activities over less stimulating ones."

Credit: 
The Lancet

Taking out the (life-threatening) garbage: Bacteria eject trash to survive

video: How smart are bacteria? They know to take out their garbage. New research by UC San Diego's Rang et al shows that bacteria make minicells to dispose of damaged proteins caused by the killer antiobiotic streptomycin. The elimination of the bad proteins allows these bacteria to resist higher levels of streptomycin than other bacteria that do not make minicells. See the publication at msphere.asm.org/content/3/5/e00428-18

Image: 
Chao Lab, UC San Diego

Scientists have known for decades that certain bacteria produce small spherical versions of themselves. Although they lack basic materials to reproduce or function like normal cells, recent interest in such "minicells" has spiked due to their proficiency as nano-sized delivery tools for drugs and vaccines to targeted cells and tissues.

Yet the natural role of minicells, which protrude like budding balloons off the ends of bacteria, has remained a mystery. Now, researchers at the University of California San Diego have demonstrated for the first time that minicells play a key function in the self-preservation of bacteria.

Publishing their results in the journal mSphere, the researchers discovered that E. coli bacteria discharge damaged proteins bundled inside minicells--a process not unlike a pod being launched from a spaceship--as a survival mechanism.

"It's amazing that even bacteria take out their garbage," said Camilla Rang, a research specialist in Division of Biological Sciences Professor Lin Chao's laboratory and first author of the paper. "We have shown that minicells can be beneficial for the bacteria and help them escape death by kicking out the damaged proteins."

To examine the link between minicells and the health of bacterial cells, the researchers tagged and tracked proteins with fluorescent markers. While under attack from antibiotics such as streptomycin, the researchers used microscopy techniques to follow damaged proteins in E. coli bacteria to the pole (end point) areas, then packaged inside the minicell and finally dispatched out of the bacteria.

"The advantage that minicells provide in the presence of streptomycin suggests that they could also play a role in helping bacterial cells resist, survive or persist when challenged with antibiotics," the researchers note in the paper.

The new findings help provide mechanistic insights for researchers who have recently used minicells as molecular drug delivery systems for diseases such as cancer. In such treatments, minicells are loaded through diffusion with therapeutic drugs, tagged with antibodies for a target cancer and injected into the blood system. The new results help describe how natural routes within minicells could instead be used for packing drug payloads.

The paper is dedicated to the memory of Distinguished Professor Emeritus William Loomis, a 50-year UC San Diego faculty member, who provided critical input to the direction of the research project. He passed away in 2016. Coauthors of the paper include UC San Diego's Audrey Proenca, Christen Buetz, Chao Shi and Lin Chao.

Credit: 
University of California - San Diego

Fecal microbiota transplantation helps restore beneficial bacteria in cancer patients

image: The Human Microbiome Project, launched by NIH in 2007, provided a glimpse of the microbial diversity of healthy humans and is exploring the possible relationship between human diseases and the microbiome.

Image: 
Jonathan Bailey, NHGRI

Researchers at Memorial Sloan Kettering Cancer Center have shown that autologous fecal microbiota transplantation (auto-FMT) is a safe and effective way to help replenish beneficial gut bacteria in cancer patients who require intense antibiotics during allogenic hematopoietic stem cell transplantation. In their study, patients who underwent the procedure were randomly assigned into two groups: one group received standard care and the other received auto-FMT. The researchers found that auto-FMT resulted in the recovery of beneficial gut bacteria to near baseline levels within days, thus restoring patients' digestive, immune and other essential functions. With standard care, beneficial bacteria typically take many weeks to recover from antibiotic treatment, leaving patients at risk of other infectious diseases, including Clostridium difficile.

The National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, provided funding for part of the project. The study report appears in Science Translational Medicine.

"This important study suggests that clinical intervention using auto-FMT can safely reverse the disruptive effects of broad-spectrum antibiotic treatment," says NIAID Director Anthony S. Fauci, M.D. "If validated in larger studies, this approach may prove to be a relatively simple way to quickly restore a person's healthy microbiome following intensive antimicrobial therapy."

Allogenic hematopoietic cell transplantation involves a donor--often but not exclusively a family member--who gives the recipient stem cells that re-establish bone marrow production of blood cells and immune function to combat cancer. Antibiotics are essential to prevent bacterial infections in stem cell recipients. However, antibiotics also destroy beneficial bacteria that enhance immune function and resistance to infection. The loss of beneficial bacteria increases the risk of certain life-threatening infectious diseases and graft-versus-host disease (GVHD).

The study involved cancer patients who provided their own fecal sample, which was frozen and stored prior to their cell transplantation procedure. Weeks later, when physicians confirmed that the transplanted cells were growing, they assessed the status of the patients' beneficial gut bacteria. The first 25 patients who lacked known beneficial bacteria were enrolled into the study and randomly assigned to the different treatment groups: 14 received auto-FMT by enema and 11 received standard-of-care.

The patients who received auto-FMT consistently regained bacterial diversity, composition and function; recovery of beneficial bacteria in the 11 control patients was delayed.

The researchers are continuing to monitor the study patients to determine if auto-FMT improves patient outcomes, such as the incidence and severity of bacterial, viral and fungal infections and the incidence and severity of GVHD. Whether FMT from a healthy donor would be as beneficial as the patient's own fecal sample at restoring beneficial bacteria remains to be studied.

Credit: 
NIH/National Institute of Allergy and Infectious Diseases

Alcohol use in patients with chronic liver disease

A review article published in the New England Journal of Medicine discusses the effects of alcohol use on various forms of liver disease, as well as the assessment and treatment of alcohol use in patients with chronic liver disease.

Liver-related mortality is increasing worldwide, due in large part to the increase in alcohol consumption. This review is very timely, as recent epidemiological studies have shown that alcohol consumption that does not reach the risky range is associated with increased morbidity and mortality.

Below is a summary of the review article:

Alcohol use is common among patients with liver disease and is associated with poor outcomes. In addition, advanced liver disease can complicate the pharmacologic treatment of alcohol use disorder and alcohol withdrawal syndrome. In fact, medications approved for alcohol use disorder are prescribed to a minority of patients, yet they could be used by patients with chronic liver disease.

Given that there is no safe threshold for alcohol consumption and, if it exists, it is likely very low, abstinence should be encouraged in patients with chronic liver disease. In addition, liver transplantation could be considered for patients who abstain from alcohol and present with progressive liver failure.

The authors conclude that alcohol use disorder treatment should be expanded in everyday clinical practice to include patients with advanced liver disease.

Credit: 
Boston Medical Center

Plant genetic resources ensure ag's future

image: Project gardener Charles Fernandez demonstrates pollination techniques used to propagate seed of wild potatoes maintained at the U.S. Potato Genebank in Sturgeon Bay, WI.

Image: 
Scott Bauer, USDA-ARS.

Imagine a gardener, plant explorer, geneticist, and computer specialist all rolled into one job. You might call that person a steward of plant genetic resources.

Plant genetic resources are any plant materials, such as seeds, fruits, cuttings, pollen, and other organs and tissues from which plants can be grown. The stewards are the breeders, researchers, farmers, genebank staff, and many others who keep them safe and utilize them.

Peter Bretting, a National Program Leader for the USDA's Agricultural Research Service, says these plant genetic materials and those who care for them are important for human survival.

"These are the materials for crop breeding which play a role in food security and plant research," he says. "Crops make up the thin green line standing between humanity and calamity. To feed the growing world population, breeders must develop new crop types that yield more on less land with less materials such as water and fertilizer."

To do this, crops must have new genetic materials that enable them to produce more food. The materials for this are conserved and provided to stewards who keep safe the future of agriculture and humanity's survival, Bretting adds.

An important part of these plant genetic resources is crop wild relatives. These are closely related to crop species but have not been domesticated by humans. They are often related to crops eaten today in some way and provide useful material for breeding, study, and preservation, says Bretting.

For example, breeders might find they want a trait like drought tolerance in a specific crop. It may be a rare quality only found in an ancestor. Luckily, breeders might be able to find what they need thanks to the stewards who are conserving the wild ancestors.

"Historically, plant genetic resource stewardship had focused on taking care of domesticated crop species," Bretting says. "Because of this, there have been fewer crop wild relatives in genebank collections than there should be, and not well-protected in nature. Thus, new plant genetic resource stewards must specifically try to safeguard crop wild relatives."

Plant genetic resources are carefully collected and stored. They are collected from the field in the form of seeds, fruits, bulbs, tubers, pollen, young plants, or cuttings. They are often selected to fill in gaps and make sure a collection covers as many plant types as possible.

Storing the plant genetic resources can take many forms. After drying, most are stored in cold or dry conditions. Depending on what they need, storage temperatures may vary between 41°F and -138°F (5°C and -150°C).

However, some cannot be kept in this way. Those must be constantly maintained as plants in field orchards or greenhouse plantings.

"Plant genetic resources are often distributed from genebanks as materials for breeding programs and as subjects of research," he says. "Requests for plant genetic resources can include seeds, fruits, bulbs, tubers, vegetative cuttings, or young plants. They are then used in crop breeding, research, and, in the end, agricultural production."

Bretting says the future of plant genetic resources and their stewards is bright and filled with new technologies. Areas like artificial intelligence could continue to improve how they collect, store, and conserve this important resource. He adds that the people behind this work are the key to its success and should be celebrated.

"Their devotion, often for decades, to conserving and providing plant genetic resources is wonderful," he says. "They often develop state-of-the-art solutions to seemingly impossible challenges. They and plant breeders serve as the 'first responders' to new crop diseases, pests, environmental extremes, and human-caused disruptions which could harm food security."

Credit: 
American Society of Agronomy

Neuroscientists see clues to brain maturation in adolescent rats

image: Neuroscientist Heather Richardson and colleagues at UMass Amherst believe their recent study of young and adolescent rat brains is the first to combine measurement of conduction velocity of axons with those of myelination during development in the medial prefrontal cortex.

Image: 
UMass Amherst

AMHERST, Mass. - One of the outstanding questions in neurodevelopment research has been identifying how connections in the brain change to improve neural function during childhood and adolescence. Now, results from a study in rats just reported by neuroscientists Heather Richardson, Geng-Lin Li and colleagues at the University of Massachusetts Amherst suggest that as animals transition into adolescence, specific physical changes to axons speed up neural transmission, which may lead to higher cognitive abilities.

Their co-author, doctoral candidate Andrea Silva-Gotay, says, "One advantage of increased conduction speed is faster processing of information; brain areas communicate faster and decisions can be made faster." Two factors that can increase conduction speed are myelination and larger axon diameter, she adds. "A thin axon will be slower, a thick one faster. Myelin can also make axons faster."

"To our knowledge, this is the first study that combines measurement of conduction velocity of axons with measurements of myelination during development in this part of the brain," Silva-Gotay points out.

Writing in the journal eNeuro, the researchers report that they have identified specific developmental changes that may be key factors underlying enhanced neural processing in the medial prefrontal cortex (mPFC) of the maturing rat brain. This is a region that integrates information from many sources to process and modulate complex functions such as stress responses, behavior control, attention, and working memory, Richardson says.

She and colleagues studied changes in axons - the long conducting threads of a nerve cell along which signals move from one cell to another - and the wrapping of these axons by myelin - the electrically insulating sheath that forms around nerve fibers at this time - in brains from groups of juvenile, pre-adolescent rats at 15 days old and mid-adolescent rats at 43 days old.

Results suggest that in animals two-to-six weeks old, axons in the mPFC undergo microstructural and electrophysiological changes that speed up neural transmission. Silva-Gotay explains, "Between those two ages we found a significant increase in how fast the electrical signals travel in the brain during pre-adolescence compared to adolescence. There is a dramatic increase. Moreover, we found this in the mPFC, which was not known before."

The authors report that signal conduction velocity in axons nearly doubled by mid-adolescence, and this corresponded with a 90-fold increase in the number of axons that were myelinated in this region. "Because axonal diameter did not change with age, we reason that myelination of these axons accounts for the significant increase in speed," senior author Richardson says. "These axonal changes could contribute to some of the developmental improvements in how well the prefrontal cortex works."

She and Silva-Gotay add that this may tell us something about other brain areas that are being myelinated around this same time in development. Electrical signals could be traveling along axons at a faster pace in these regions as well. "It is also important to consider factors that could interfere with this myelination process. We and others have found that alcohol can reduce myelin in this part of the brain. It is possible that the speed of transmission in these axons was negatively affected as well," Richardson says. "That's something we can test in a future study," adds Silva-Gotay.

Credit: 
University of Massachusetts Amherst

ZSL names world's largest ever bird -- Vorombe titan

image: An artist's illustration of the giant elephant bird.

Image: 
(c) Jaime Chirinos

After decades of conflicting evidence and numerous publications, scientists at international conservation charity ZSL's (Zoological Society of London) Institute of Zoology, have finally put the 'world's largest bird' debate to rest. Published today (26 September 2018) in Royal Society Open Science - Vorombe titan (meaning 'big bird' in Malagasy and Greek), has taken the title reaching weights of up to 800 kg and three metres tall, with the research also discovering unexpected diversity in these Madagascan creatures.

Until now, it was previously suggested that up to 15 different species of elephant birds had been identified under two genera, however research by ZSL scientists boasts new rigorous and quantitative evidence - that shows, in fact, this is not the case. Armed with a tape measure and a pair of callipers, Dr Hansford analysed hundreds of elephant bird bones from museums across the globe to uncover the world's largest bird, while also revealing their taxonomy is in fact spread across three genera and at least four distinct species; thus, constituting the first taxonomic reassessment of the family in over 80 years.

Elephant birds (belonging to the family Aepyornithidae) are an extinct group of colossal flightless birds that roamed Madagascar during the Late Quaternary, with two genera (Aepyornis and Mullerornis) previously recognised by scientists. The first species to be described, Aepyornis maximus, has often been considered to be the world's largest bird. In 1894, British scientist C.W. Andrews described an even larger species, Aepyornis titan, this has usually been dismissed as an unusually large specimen of A. maximus. However, ZSL's research reveals Andrew's 'titan' bird was indeed a distinct species. The shape and size of its bones are so different from all other elephant birds that it has now been given the new genus name Vorombe by ZSL.

Lead Author at ZSL's Institute of Zoology, Dr James Hansford said: "Elephant birds were the biggest of Madagascar's megafauna and arguably one of the most important in the islands evolutionary history - even more so than lemurs. This is because large-bodied animals have an enormous impact on the wider ecosystem they live in via controlling vegetation through eating plants, spreading biomass and dispersing seeds through defecation. Madagascar is still suffering the effects of the extinction of these birds today."

Co-Author Professor Samuel Turvey from ZSL's Institute of Zoology said: "Without an accurate understanding of past species diversity, we can't properly understand evolution or ecology in unique island systems such as Madagascar or reconstruct exactly what's been lost since human arrival on these islands. Knowing the history of biodiversity loss is essential to determine how to conserve today's threatened species."

Analysing this data in a novel combination of machine learning combined with Bayesian clustering, Dr Hansford applied modern techniques to solve a 150-year-old taxonomic knot, that will form the modern understanding of these enigmatic avian megafauna. The revelation that the biggest of these birds was forgotten by history is just one part of their remarkable story.

Credit: 
Zoological Society of London

Robots may need lizard-like tails for 'off-road' travel

image: An example of an Australian lizard, in this case the Gippsland Water Dragon, running on two legs.

Image: 
David Paul

Robots may one day tackle obstacles and traverse uneven terrains thanks to collaborative research analysing the motion of lizards.

The study, which featured a University of Queensland researcher, used a slow motion camera to capture the nuanced movement of eight species of Australian agamid lizards that run on two legs - an action known as 'bipedal' movement.

UQ School of Biological Sciences researcher Nicholas Wu said the study's findings challenged existing mathematical models based on the animals' movement.

"There was an existing understanding that the backwards shift in these lizards' centre of mass, combined with quick bursts of acceleration, caused them to start running on two legs at a certain point," he said.

"It's just like a motorcycle driver doing a 'wheelie'.

"What we found though is that some lizards run bipedally sooner than expected, by moving their body back and winging their tail up.

"This means that they could run bipedally for longer, perhaps to overcome obstacles in their path."

Lead author Christofer Clemente from the University of the Sunshine Coast said these results may have important implications for the design of bio-inspired robotic devices.

"We're still teasing out why these species have evolved to run like this in the first place, but as we learn more, it's clear that these lessons from nature may be able to be integrated into robotics," Dr. Clemente said.

"It's been suggested that this movement might have something to do with increasing vision in moments of urgency, by elevating the head at the same time and helping to navigate over obstacles.

"Indeed, bipedalism would be advantageous for robots in specific habitats, for example, on open grasslands where, in nature, many bipedal running agamids are found.

"If obstacle negotiation is indeed improved with bipedal locomotion, then we have shown how the tail and body can be moved to enable it sooner and for longer.

"Maybe adding a tail to robots can help them go 'off-road' sooner."

The research is not only looking to the future, but to the past, by helping explain the evolution of bipedalism in dinosaurs and how they could have transitioned from walking on four legs to two legs.

Credit: 
University of Queensland

Sensitive babies become altruistic toddlers

image: Infant in the fNIRS (neuroimaging) lab

Image: 
Kathleen Krol, <a href="kmk5eg@virginia.edu">kmk5eg@virginia.edu</a>

Our responsiveness to seeing others in distress accounts for variability in helping behavior from early in development, according to a study published September 25 in the open-access journal PLOS Biology by Tobias Grossmann of the University of Virginia, and colleagues.

Altruistic behavior such as helping an unfamiliar person in need is considered a key feature of cooperation in human societies. Yet our propensity to engage in altruistic acts varies considerably among individuals, ranging from extraordinarily altruistic kidney donors to highly antisocial psychopaths. Past studies have suggested that greater sensitivity to fearful faces is linked to heightened levels of prosocial behavior, which can already be seen in preschool children. Examining responsiveness to fearful faces and its variability early in human development represents a unique opportunity to shed light on the precursors of altruistic behavior.

To address this question, Grossmann and colleagues tracked eye movements to examine whether attentional responses to fear in others at seven months of age predict altruistic behavior at 14 months of age. The analysis revealed that altruistic behavior in toddlerhood was predicted by infants' attention to fearful faces but not happy or angry faces. Moreover, infants' attentional bias to fearful faces and their altruistic behavior was predicted by brain responses in the dorsolateral prefrontal cortex measured through functional near-infrared spectroscopy.

According to the authors, the findings suggests that, from early in development, variability in altruistic helping behavior is linked to our responsiveness to seeing others in distress and brain processes implicated in attentional control. These findings critically advance our understanding of the emergence of altruism in humans by identifying responsiveness to fear in others as an early precursor contributing to variability in prosocial behavior.

"Our results are in line with the notion that a caring continuum exists, along which individuals differ in their tendency to display sensitive responses to others' distress that motivate prosocial action," said Grossmann. "This study provides new insights into the nature of human altruism by uncovering its developmental and brain origins."

Credit: 
PLOS

The soothing effects of strangers

Is pain treatment more helpful if it is provided by a person from our own social group, or is the help of a stranger more efficient? A study conducted by researchers from the Universities of Wuerzburg, Amsterdam and Zurich investigated this question and found that people experience a stronger pain relief if they are treated by a person that belongs to a different social group.

The study has been published in the latest issue of the Royal Society of London B: Biological Sciences. It was led by Grit Hein, a psychologist, neuroscientist and professor of Translational Social Neuroscience at the Center of Mental Health of the Würzburg University Hospital who teamed up with Jan B. Engelmann (Amsterdam) and Philippe N. Tobler (Zurich).

"Participants received pain on the back of their hand. In one group of participants, this pain was relieved by a person from their own social group, another group of participants received pain relief from a person from a different group. We measured how the pain relief treatment changed neural pain responses and subjective pain judgments." Grit Hein describes the scientists' approach.

Treatment by a stranger was more efficient

The result: "Before the treatment, both groups showed similarly strong responses to pain," Grit Hein explains. "In contrast, after being treated by what they considered a "stranger", the participants from this group rated their pain less intense than the other group. The effect was not limited to the subjective pain experience: "We also saw a reduction of the pain-related activation in the corresponding brain regions," the scientist says.

While being surprising to the lay person, the finding is in line with a core principle of learning theory according to which people learn particularly well when the results differ significantly from what they had expected. This is called "prediction error learning" in psychological language where the surprise contributes to "rooting" the new experience more effectively in the brain.

Analgesic effect of surprise

Related to the pain experiment, this means the following: "The participants who received pain relief from an outgroup member had not expected to actually get effective help from this person," the neuroscientist explains. And the less the participants had anticipated positive experiences, the bigger their surprise when the pain actually subsided and the more pronounced the reduction of their pain responses. "Of course this finding still needs to be verified outside the laboratory", says Grit Hein, " but it could be relevant for the clinical context where treatment by nurses and doctors from different cultures is common today."

Credit: 
University of Würzburg