Watching water droplets merge on the international space station

Peer-Reviewed Publication

AMERICAN INSTITUTE OF PHYSICS

 

VIDEO: DROPLETS (ON THE CENTIMETER SCALE) MERGE DURING AN EXPERIMENT ON THE INTERNATIONAL SPACE STATION. view more 

CREDIT: JOSH MCCRANEY

WASHINGTON, Dec. 13, 2022 – Understanding how water droplets spread and coalesce is essential for scenarios in everyday life, such as raindrops falling off cars, planes, and roofs, and for applications in energy generation, aerospace engineering, and microscale cell adhesion. However, these phenomena are difficult to model and challenging to observe experimentally.

In Physics of Fluids, by AIP Publishing, researchers from Cornell University and Clemson University designed and analyzed droplet experiments that were done on the International Space Station.

Droplets usually appear as small spherical caps of water because their surface tension exceeds gravity.

"If the drops get much larger, they begin to lose their spherical shape, and gravity squishes them into something more like puddles," said author Josh McCraney of Cornell University. "If we want to analyze drops on Earth, we need to do it at a very small scale."

But at small scales, droplets dynamics are too fast to observe. Hence, the ISS. The lower gravity in space means the team could investigate larger droplets, moving from a couple millimeters in diameter to 10 times that length.

The researchers sent four different surfaces with various roughness properties to the ISS, where they were mounted to a lab table. Cameras recorded the droplets as they spread and merged.

"NASA astronauts Kathleen Rubins and Michael Hopkins would deposit a single drop of desired size at a central location on the surface. This drop is near, but not touching, a small porthole pre-drilled into the surface," said McCraney. "The astronaut then injected water through the porthole, which collects and essentially grows an adjacent drop. Injection continues until the two drops touch, at which point they coalesce."

The experiments aimed to test the Davis-Hocking model, a simple way to simulate droplets. If a droplet of water sits on a surface, part of it touches the air and creates an interface, while the section in contact with the surface forms an edge or contact line. The Davis-Hocking model describes the equation for the contact line. The experimental results confirmed and expanded the parameter space of the Davis-Hocking model.

As the original principal investigator of the project, the late professor Paul Steen of Cornell University had written grants, traveled to collaborators worldwide, trained doctoral students, and meticulously analyzed related terrestrial studies, all with the desire to see his work successfully conducted aboard the ISS. Tragically, Steen died only months before his experiments launched.

"While it's tragic he isn't here to see the results, we hope this work makes him and his family proud," said McCraney.

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The article "Coalescence-induced droplet spreading: Experiments aboard the International Space Station" is authored by Joshua McCraney, Jonathan Michael Ludwicki, Joshua Bostwick, Susan Daniel, and Paul Steen. The article will appear in Physics of Fluids on Dec. 13, 2022 (DOI: 10.1063/5.0125279). After that date, it can be accessed at https://doi.org/10.1063/5.0125279.

ABOUT THE JOURNAL

Physics of Fluids is devoted to the publication of original theoretical, computational, and experimental contributions to the dynamics of gases, liquids, and complex fluids. See https://aip.scitation.org/journal/phf.

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JOURNAL

Physics of Fluids

DOI

10.1063/5.0125279 

ARTICLE TITLE

Coalescence-induced droplet spreading: Experiments aboard the International Space Station

ARTICLE PUBLICATION DATE

13-Dec-2022

Scientists get first-ever sound recording of dust devils (tiny tornadoes of dust, grit) on Mars

Peer-Reviewed Publication

PURDUE UNIVERSITY

WEST LAFAYETTE, Ind. – When the rover Perseverance landed on Mars, it was equipped with the first working microphone on the planet’s surface. Scientists have used it to make the first-ever audio recording of an extraterrestrial whirlwind.

The study was published in Nature Communications by planetary scientist Naomi Murdoch and a team of researchers at the National Higher French Institute of Aeronautics and Space and NASA. Roger Wiens, professor of earth, atmospheric and planetary sciences in Purdue University’s College of Science, leads the instrument team that made the discovery. He is the principal investigator of Perseverance’s SuperCam, a suite of tools that comprise the rover’s “head” that includes advanced remote-sensing instruments with a wide range of spectrometers, cameras and the microphone. 

“We can learn a lot more using sound than we can with some of the other tools,” Wiens said. “They take readings at regular intervals. The microphone lets us sample, not quite at the speed of sound, but nearly 100,000 times a second. It helps us get a stronger sense of what Mars is like.”

The microphone is not on continuously; it records for about three minutes every couple of days. Getting the whirlwind recording, Wiens said, was lucky, though not necessarily unexpected. In the Jezero Crater, where Perseverance landed, the team has observed evidence of nearly 100 dust devils – tiny tornadoes of dust and grit – since the rover’s landing. This is the first time the microphone was on when one passed over the rover.

The sound recording of the dust devil, taken together with air pressure readings and time-lapse photography, help scientists understand the Martian atmosphere and weather.

“We could watch the pressure drop, listen to the wind, then have a little bit of silence that is the eye of the tiny storm, and then hear the wind again and watch the pressure rise,” Wiens said. It all happened in a few seconds. “The wind is fast — about 25 miles per hour, but about what you would see in a dust devil on Earth. The difference is that the air pressure on Mars is so much lower that the winds, while just as fast, push with about 1% of the pressure the same speed of wind would have back on Earth. It's not a powerful wind, but clearly enough to loft particles of grit into the air to make a dust devil.”

The information indicates that future astronauts will not have to worry about gale-force winds blowing down antennas or habitats — so future Mark Watneys won’t be left behind — but the wind may have some benefits. The breezes blowing grit off the solar panels of other rovers — especially Opportunity and Spirit — may be what helped them last so much longer.

“Those rover teams would see a slow decline in power over a number of days to weeks, then a jump. That was when wind cleared off the solar panels,” Wiens said.

The lack of such wind and dust devils in the Elysium Planitia where the InSIght mission landed may help explain why that mission is winding down.

“Just like Earth, there is different weather in different areas on Mars,” Wiens said. “Using all of our instruments and tools, especially the microphone, helps us get a concrete sense of what it would be like to be on Mars.” 

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JOURNAL

Nature Communications

DOI

10.1038/s41467-022-35100-z 

ARTICLE TITLE

The sound of a Martian dust devil

ARTICLE PUBLICATION DATE

13-Dec-2022

SOLIDARITY MUTUAL AID

Strong connection to neighbors may improve health outcomes

Rutgers researchers examine whether the perception of trust and connection within a neighborhood reduced the impact on risk of death

Peer-Reviewed Publication

RUTGERS UNIVERSITY

Strong neighborhood connections reduced the negative impact of living alone on the death rates of older Chinese Americans, according to Rutgers researchers.

 

The study, published in Social Science and Medicine, examined if neighborhood cohesion in Chinese Americans living in the greater Chicago area would reduce the impact of living alone on early death.

 

“Older Chinese Americans who lived by themselves in neighborhoods with low cohesion were much more likely to die earlier than those who lived by themselves in neighborhoods with strong cohesion,” said Yanping Jiang, author of the study and faculty member at the Center for Population Behavioral Health at Rutgers Institute for Health, Health Care Policy and Aging Research.

 

In the United States, about 27 percent of people ages 60 and older live alone, according to Pew Research Center. Living alone has been found to be associated with various poor health outcomes, such as depression, cardiovascular disease, dementia, poor biological health and premature death. Therefore, researchers found it important to identify which factors may help mitigate the negative effects of living alone.

 

Using data from the Population Study of Chinese Elderly in Chicago (PINE), the researchers examined whether the perception of trust and connection among neighbors had an impact on the risk of death in this population. They found participants who lived alone and reported low interaction or connection with their neighbors had a 48.5 percent increased risk of death than their peers living with others, whereas participants who lived alone and reported strong cohesion with their neighborhood had a similar risk of death compared to those living with others.

 

With a clearer understanding of how different types of neighborhoods can affect the health of individuals, social policies and public health initiatives can be improved to create better neighborhood environments for promoting health of older adults, researchers said.

 

“Our findings show the particular challenges faced by older adults who live alone in communities with little interaction or connection,” said Jiang, who is an instructor at the Rutgers Department of Family Medicine and Community Health. “Enhancing neighborhood cohesion may be a promising way to reduce early death for older adults who live alone.”

 

Researchers encourage future studies to examine other factors involved in neighborhoods and how they influence the health of older adults. Additionally, the public also can play a role in improving community health by reaching out and being kind to neighbors, particularly those who live alone.

 

Coauthors of the study include Mengting Li of Renmin University of China and Tammy Chung of Rutgers Institute for Health, Health Care Policy and Aging Research. Research was supported by the Rutgers-NYU Center for Asian Health Promotion and Equity and the National Institute on Aging.

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JOURNAL

Social Science & Medicine

DOI

10.1016/j.socscimed.2022.115568 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Living alone and all-cause mortality in community-dwelling older adults: The moderating role of perceived neighborhood cohesion

 

Feeding apple waste to chickens may boost their health

Peer-Reviewed Publication

CORNELL UNIVERSITY

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ITHACA, N.Y. -- An apple a day may keep the livestock veterinarian away. Juice, pulp and other waste from Empire apples, when injected into chicken eggs before hatching, show signs of boosting the animal’s intestinal health, according to Cornell research.

“Apples are one of the top fruits produced in the United States and we have long been aware of their health benefits,” said lead author Cydney Jackson, a doctoral student in the field of food science.

“In our study, we were able to see how an apple – specifically, the Empire apple developed at Cornell in the 1940s – improved the intestinal health of production broilers, and we observed signs for the overall good health of the bird,” Jackson said.

The researchers injected juice, pomace and pulp – in vivo – into the amniotic fluid of the developing embryo inside a chicken egg. After the eggs were hatched, relevant samples were collected for analyses.

The researchers found that introducing apple juice and pomace into the egg can increase the young chicken’s transport system for amino acids, improve the bioavailability of iron, boost the microbial populations in the animal’s large intestine and support the growth of potentially beneficial gut bacteria.

“Apples are comprised of bioactive constituents such as phytochemicals and prebiotics that could help intestinal health and the gut microbiome,” said senior author Elad Tako, associate professor of food science in the College of Agriculture and Life Sciences (CALS) and a co-author of the paper.

Each year, the U.S. sees nearly $20 billion in apple sales, with an estimated 5 million tons of the fruit produced annually in the U.S. within the last decade, according to the paper.

For juice and apple production, about 33.4 million bushels of apples were used in 2021-22, according to the U.S. Apple Association. Nearly 175,350 metric tons of apple pomace – the fibrous waste – is produced annually and typically tossed away in landfills, according to the paper. This damages the environment, as it disrupts the carbon-nitrogen ratio of soil due to the pomace’s sugar content.

“Pomace is treated like industrial waste now. If we can potentially use the pomace, which is rich in nutrients, we can add it to the diet of broilers,” Tako said. “We can improve the nutrition in their feed and achieve productivity in a more natural way – and potentially reduce the use of added dietary chemicals.”

The researchers said this was an initial study to demonstrate the potential effect for adding apple waste to chicken feed and they indicated a need for long-term studies.

Said Tako: “Potentially, we’ll be upscaling industrial waste that is currently being discarded. That’s sustainable.”

In addition to Jackson and Tako, the co-authors of “Empire Apple (Malus domestica) Juice, Pomace, and Pulp Modulate Intestinal Functionality, Morphology, and Bacterial Populations In Vivo (Gallus gallus)” are Cornell doctoral students Viral Shukla, Nikolai Kolba and Nikita Agarwal; and Olga I. Padilla-Zakour, professor of food science.

Funding for the research was provided by the National Institute of Food and Agriculture, U.S. Department of Agriculture.

-30-

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JOURNAL

Nutrients

DOI

10.3390/nu14234955 

Morgue data reveal Africa’s high COVID-19 death toll

A new study led by Boston University School of Public Health found that nearly 90 percent of deceased individuals at a Zambian morgue were infected with COVID-19, but only 10 percent tested positive while alive.

Peer-Reviewed Publication

BOSTON UNIVERSITY SCHOOL OF PUBLIC HEALTH

A new study led by Boston University School of Public Health found that nearly 90 percent of deceased individuals at a Zambian morgue were infected with COVID-19, but only 10 percent tested positive while alive.

Since the start of the pandemic, Africa has reported more than 12 million COVID-19 cases and nearly 260,000 deaths—totals that seem vast, but pale in comparison to reported cases and deaths among countries in North America, Europe, and Asia. By contrast, the United States has amassed almost 100 million cases and nearly 1.08 million recorded COVID-19 deaths to date, including as many as 5,000 deaths in a single day during the winter 2021 surge.

Africa’s low death count has baffled health experts and government officials, but growing data contrasts previous, widespread assertions over the last three years that COVID-19 spared the continent.

A new study led by Boston University School of Public Health (BUSPH) researchers suggests that the reported COVID-19 death toll in Africa is substantially higher than official records indicate.

Published in the journal BMJ Open, the study found that nearly 90 percent of deceased individuals at a crowded morgue in Lusaka, Zambia were infected with COVID-19 during peak transmission periods between July 2020-June 2021—and only 10 percent of these individuals tested positive for COVID while alive.

Study lead authors Dr. Christopher Gill, professor of global health at BUSPH, and Dr. Lawrence Mwananyanda, adjunct research assistant professor of global health at BUSPH, are confident that the majority of these deceased people died from COVID-19, rather than from other causes.

“It is always challenging to know whether someone died with COVID or died from COVID,” says Dr. Gill, who has studied a wide range of infectious diseases, particularly pediatric illnesses, and vaccines in the US and abroad. “What we can say is that a majority of the deceased presented with some constellation of respiratory symptoms on top of the positive PCR test.”

Furthermore, he says, the research team performed lung biopsies on a subset of the decedents, and found evidence of lung pathology consistent with COVID disease. “This does not completely eliminate the possibility that some of the deaths could have been misclassified as COVID deaths when, in fact, the virus was a coincidental finding—but overall, the evidence supports COVID as the cause of death in most cases.”

The findings build upon the researchers’ previous postmortem surveillance of COVID-19 at the same morgue in Lusaka—but among a much smaller group of people and within a shorter time period—published in The BMJ in February 2021. The study found that 15-19 percent of 70 decedents tested positive for the virus between June-October 2020, with the majority of deaths occurring outside of hospitals and in communities where COVID-19 testing was sparse, if not nonexistent.

The new results represent 1,118 decedents among three waves of the pandemic, stemming from the more contagious Beta and Delta variants and peaking in July 2020, January 2021, and June 2021. Similar to the previous findings, Dr. Gill and Dr. Mwananyanda found that the majority of deaths occurred outside of medical facilities, and in impoverished communities. Across the study time period, 32 percent of the deceased individuals tested positive for COVID-19, but that percentage rose to 89.3 percent during the peak times, and 4 out of 5 COVID-19 deaths occurred in the community instead of at a hospital. 

“This is an example of what it means to be a resource-poor country,” Dr. Gill says. “We tend to think of this just in terms of poor health and a high incidence of infectious diseases, but it also reflects the ability of poorer countries to map the impact of such diseases on its populations. Rather than an ‘African paradox,’ the far simpler explanation is that COVID-19 has affected African countries just as the virus has everywhere else, but has gone undocumented.”

Earlier in the pandemic, “there was often an assumption that COVID-19 deaths would be obvious and easy to find,” Dr. Gill says. But that assumption has been disproven over the past two years, he says, pointing to excess mortality statistics in New York City, as one example, in which excess COVID-19 deaths have far surpassed reported case that were diagnosed while people were living.

“That ‘excess mortality’ tells us that it is not so easy to link a viral infection to a death, even in the midst of a pandemic, and even when the suspicion of COVID-19 should be high,” he says. “It is simply a reflection that our capacity for postmortem surveillance is rarely complete. If we take that lesson from NYC to Lusaka—a city that is extremely poor and has very few resources for surveillance—it is easy to see how COVID-19 deaths could be undercounted. This is one example of what it means to be a resource-poor country.”

The reasons for these higher death counts are still unclear. Many surmise that Africa’s younger population or greater exposure to COVID-19 or other diseases, such as malaria, may produce greater immunity to severe cases and deaths—with some officials stating that a high number of deaths would not go unnoticed in local communities.

Dr. Gill hopes that this study increases awareness among health experts, government officials, and the general public, of the true toll of the pandemic in Lusaka, and likely throughout Africa. Wider access to rapid tests and vaccines remains essential, he says.

“I would love to believe that we have seen the worst of COVID-19 at this point, but this disease has surprised us in the past,” Dr. Gill says. “It is better to be prudent and take this opportunity to vaccinate as much of the population as we can, particularly now, when the healthcare systems are not under as much acute stress as they were in the worst days of 2021.”

**

About Boston University School of Public Health
Founded in 1976, Boston University School of Public Health is one of the top five ranked private schools of public health in the world. It offers master's- and doctoral-level education in public health. The faculty in six departments conduct policy-changing public health research around the world, with the mission of improving the health of populations—especially the disadvantaged, underserved, and vulnerable—locally and globally.

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DOI

10.1136/bmjopen-2022-066763 

METHOD OF RESEARCH

Systematic review

SUBJECT OF RESEARCH

People

ARTICLE TITLE

What is the prevalence of COVID-19 detection by PCR among deceased individuals in Lusaka, Zambia? A postmortem surveillance study

New look at an ancient disease: Study finds novel treatment targets for gout

UC San Diego scientists identify a new model of the arthritic disease, centered on the joint lubricating protein lubricin

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - SAN DIEGO

 

IMAGE: JAMES GILLRAY’S 1799 PAINTING ILLUSTRATES THE PAINFUL SYMPTOMS OF GOUT. view more 

CREDIT: WELLCOME LIBRARY, LONDON / HTTPS://CREATIVECOMMONS.ORG/LICENSES/BY/4.0/

Many Americans think of gout as a disease from a bygone era, akin to rickets or scurvy. The condition commonly afflicted the rich and royal, including American historical figures such as Benjamin Franklin and Thomas Jefferson.

Gout is indeed one of the earliest known diseases, first identified by the ancient Egyptians around 2640 BC. But the disease is more prevalent now than ever, affecting more than 10 million people in the United States or approximately 5 percent of the adult population. 

Gout is the most common form of inflammatory arthritis, in which urate (a byproduct of purine-rich foods like meat and alcohol) builds up in the body and forms needle-shaped crystals in and around the joints, usually starting in the foot. The crystal deposits lead to flares of severe pain, joint swelling and tenderness, and can progress to chronic joint damage that limits patients’ movement and quality of life.

Excess urate circulating in the blood (known as hyperuricemia) has long been considered the major cause of gout, but counterintuitively, most people with high urate levels do not actually develop the disease. In fact, asymptomatic hyperuricemia is approximately four times more prevalent than gout. Gout patients also show mysteriously higher levels of urate in their joint fluid compared to their blood. Thus hyperuricemia must not be the only thing stimulating urate crystal deposition in the joints. So what else could be causing the disease?

In a new study published online on December 1, 2022 in Arthritis & Rheumatology, an international research team led by University of California San Diego School of Medicine identified a novel molecular pathway that causes gout and its progression to joint tissue erosion. The findings position lubricin, a protein found in joint fluid, as a novel therapeutic target for both the prevention and treatment of the disease.

The scientists were interested in exploring the genetic factors that lead not to high levels of circulating urate, but specifically to urate production and crystal deposition within joints. To do this, they studied a rare case of gout in which the patient had developed urate crystal deposits and erosion in her joints but did not show high levels of urate in her blood. 

“This naturally occurring and extremely unusual disorder provided a unique opportunity to look at gouty arthritis through a different lens, and understand what molecular processes contribute to the disease independent of hyperuricemia,” said senior author Robert Terkeltaub, MD, professor at UC San Diego School of Medicine and section chief of Rheumatology at the Veterans Affairs San Diego Healthcare System.

Using whole genome sequencing, RNA-sequencing and quantitative proteomic methods, the researchers were able to identify a major molecular pathway that was disrupted in the patient, centering on a significant reduction in lubricin. The mucinous protein provides essential lubrication and protection to joint tissues, and regulates the function of a specific type of white blood cell that promotes inflammation in the joint.

Additional experiments confirmed that under healthy conditions, lubricin suppresses the secretion of urate and xanthine oxidase (an enzyme that produces urate) by activated white blood cells, and also blocks urate from crystallizing in the joint. The researchers then assessed several patients with the common form of gout and confirmed that they too had markedly decreased levels of lubricin.

The authors suggest that whether or not a hyperacemia patient goes on to develop gout may thus be influenced by which gene variants they have for lubricin and other molecules that control its production or degradation in the joint. 

“Our findings show that lubricin may be a new biomarker for tracing patients’ risk of developing gout, and that new drugs to maintain and increase lubricin could limit the incidence and progression of gouty arthritis,” said Terkeltaub.

Co-authors include: Leigh-Ana Rossitto, Ru LiuBryan, Majid Ghassemian, Anaamika Campeau and David J. Gonzalez at UC San Diego; Marin Miner at Veterans Affairs San Diego Healthcare System; Khaled Elsaid and Sandy Elsayed at Chapman University; Amanda Phipps-Green, Tony R. Merriman and Murray Cadzow at University of Otago; Jacob Karsh at University of Ottawa; Gregory D. Jay at Rhode Island Hospital; Marwa Qadri at Jazan University; Talia J. Dambruoso at Brown University; Tannin Schmidt at University of Connecticut Health Center; Nicola Dalbet and Ashika Chhana at University of Auckland; Jennifer Höglund at University of Gothenburg; Nancy Maltez at Ottawa Riverside Hospital; and Niclas G. Karlsson at Oslo Metropolitan University. 

A radiograph of the patient’s foot revealed punched-out joint erosions in the big toe, features characteristic of tophaceous, erosive gout.

CREDIT

UC San Diego Health Sciences

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JOURNAL

Arthritis & Rheumatology

DOI

10.1002/art.42413 

COI STATEMENT

Robert Terkeltaub has served as a consultant for Dyve Biosciences, Fortress Bio, Allena and Acquist; Nicola Dalbet has served as a consultant for AstraZeneca, Dyve Biosciences, Horizon, Amgen, Selecta, Arthrosi, JW Pharmaceutical Corporation, PK Med, PTC Therapeutics and Protalix; Khaled Elsaid holds a patent on the use of rhPRG4 for treatment of acute gout; Tannin Schmidt has authored patents on rhPRG4 and is a paid consultant and holds equity in Lubris LLC; Gregory D. Jay has authored patents on lubricin and holds equity in Lubris LLC; Niclas G. Karlsson has authored a patent on lubricin as a biomarker and holds equity in Lynxon AB.

Reducing opioids prescribed after total knee and hip arthroplasty can be beneficial for patients and doctors

Peer-Reviewed Publication

MICHIGAN MEDICINE - UNIVERSITY OF MICHIGAN

Opioids are commonly prescribed to patients that are discharged after a total knee and hip arthroplasty. Patients are typically given larger prescriptions of opioids that can result in an excess of the medication in their home after recovery is over.  

In the research study “Association Between Initial Prescription Size and Likelihood of Opioid Refill After Total Knee and Hip Arthroplasty” published in The Journal of Arthroplasty, Elizabeth Dailey, M.D., Clinical Assistant Professor of Orthopaedic Surgery at the University of Michigan Health System and colleagues looked at the effect of providing smaller initial opioid prescriptions on the risk of refill in the first 30 days after surgery.

Opioid addiction is an epidemic in the United States, but the medication is still commonly prescribed to treat pain after surgery inside and outside of the hospital setting. In recent years, doctors have given their post-surgery patients larger doses of opioids to avoid patients frequently calling their doctors for refills.

“The goal was to come up with a quality improvement program that would decrease the dosage of opioids given to patients leaving the hospital,” said Dailey.

Dailey and colleagues utilized private and Medicare insurance data to create a large, nationally representative cohort of hip and knee arthroplasty patients. The initial opioid prescription size was then correlated with risk of refill, and results showed that patients who were prescribed less opioids did not require more refills.

“Prescribing patients less opioids creates less of a chance of them having an excess of opioids in their home after recovery,” Dailey said. “It also creates an opportunity for doctors and patients to have a conversation about the risks continuing opioids if the patient calls for a refill.”

According to the Center for Disease Control, opioids are currently the main driver of drug overdose deaths in the United States.

Additional authors: Viktor C. Tollemar, M.D., Andrew G. Urquhart, M.D., Brian R. Hallstrom, M.D., from the Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, Michigan. Hsou-Mei Hu PhD, MBA, MHS and Jennifer F. Waljee, MD, MPH, MS from the Department of Surgery, University of Michigan, Ann Arbor, Michigan and Opioid Prescribing Engagement Network, Institute for Health care Policy and Innovation, University of Michigan Ann Arbor, Michigan. Mark C. Bicket, MD, PhD and Chad M. Brummett, MD from the Opioid Prescribing Engagement Network, Institute for Health care Policy and Innovation, University of Michigan Ann Arbor, Michigan and the Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan.

Funding: JW, MB, and CB receive funding from the Michigan Department of Health and Human Services and the National Institute of Drug Abuse (RO1DA042859). Additional funding from the University of Michigan Precision Health Initiative.

Paper cited: “Association Between Initial Prescription Size and Likelihood of Opioid Refill After Total Knee and Hip Arthroplasty,” The Journal of Arthroplasty. DOI: 10.1016/j.arth.2022.10.038

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JOURNAL

The Journal of Arthroplasty

DOI

10.1016/j.arth.2022.10.038 

METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Association Between Initial Prescription Size and Likelihood of Opioid Refill After Total Knee and Hip Arthroplasty

New study sheds light on boric acid transport and excretion in marine fish

Peer-Reviewed Publication

TOKYO INSTITUTE OF TECHNOLOGY

 

IMAGE: - view more 

CREDIT: TOKYO TECH

Marine fishes live in highly saline environments with ionic concentrations that are vastly different from their blood plasma. Seawater contains a variety of toxic ion species that can build up in the body if the fish does not excrete them. One example of this is boric acid, which—in small amounts—is a vital micronutrient for animals but can prove toxic in excess. Hence, marine fish must develop physiologic means to excrete boric acid. However, how they do this is, as yet, unknown. Now, an international team led by researchers from Tokyo Institute of Technology (Tokyo Tech) has unveiled and demonstrated the molecular mechanisms underlying boric acid secretion in marine pufferfish.

Associate Professor Akira Kato of Tokyo Tech is the principal author of the study, which was published in the Journal of Biological Chemistry. He tells us more about it. “We compared euryhaline pufferfish (which are pufferfish that can survive in varying levels of salinity) accustomed to saltwater, brackish water, and freshwater. On comparing fish from these three habitats, we found that the urine of a seawater pufferfish (Takifugu pufferfish) contained 300 times more boric acid than pufferfish blood, and 60 times more boric acid than seawater.” The urine of freshwater fish contained almost 1000 times less boric acid than that of seawater pufferfish. These findings established that Takifugu pufferfish living in seawater excrete boric acid in their urine. Just like in humans, the process of excretion via urine in pufferfish is mediated by the kidneys.

How did this boric acid enter the kidney tubules, though?

The team found that Takifugu pufferfish expressed an uncharacterized gene, Slc4a11A, in their kidney tubules. This gene encodes a protein homologous to BOR1, which is a boric acid transporter found in plants.

A detailed electrophysiological analyses of the pufferfish Slc4a11A function revealed that Slc4a11A functions as an active or electrogenic boric acid transporter,” further discusses Dr. Kato.

This basically means Slc4a11A can transport boric acid against a concentration gradient, and its function is independent of other ions like sodium. This is particularly important as it is the first report of active boric acid transport mechanism in an animal species.

Mammals have the Slc4a11 gene as well, leading to questions whether they could also be able to function like this. While we know that mammalian Slc4a11 does not transport boric acid, human mutations in the Slc4a11 gene cause visual impairments like congenital hereditary endothelial corneal dystrophy and Fuchs’ endothelial corneal dystrophy. Further research into the activities of Slc4a11 in different vertebrate species will reveal whether mammalian Slc4a11 lost its boric acid transport activity with evolution, or seawater fish Slc4a11A acquired it as they evolved.

In any case, this resounding work opens new pathways towards understanding boric acid transport in animals and unlocking the mysteries that genetics has in store.

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JOURNAL

Journal of Biological Chemistry

DOI

10.1016/J.JBC.2022.102740 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Seawater fish use an electrogenic boric acid transporter, Slc4a11A, for boric acid excretion by the kidney