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Can at-home DNA tests predict how you’ll respond to your medications? Pharmacists explain the risks and benefits of pharmacogenetic testing

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Can at-home DNA tests predict how you'll respond to your medications? Pharmacists explain the risks and benefits of pharmacogenetic testing

Pharmacogenetic testing is a form of precision medicine, using your genes to personalize your care.
D3Damon/E+ via Getty Images

Kayla B. Rowe, University of Pittsburgh; Lucas Berenbrok, University of Pittsburgh, and Philip Empey, University of Pittsburgh

Have you ever wondered why certain medications don't seem to work as well for you as they do for others? This variability in drug response is what pharmacogenomic testing hopes to explain by looking at the genes within your DNA.

Pharmacogenomics, or PGx, is the study of how genes affect your response to medications. Genes are segments of DNA that serve as an instruction manual for cells to make proteins. Some of these proteins break down or transport certain medications through the body. Others are proteins that medications target to generate a desired effect.

As pharmacists who see patients who have stopped multiple medications because of side effects or ineffectiveness, we believe pharmacogenomic testing has the potential to guide professionals to more precise dosing and prescribing.

How do PGx tests work?

PGx tests look for variations within the genes of your DNA to predict drug response. For instance, the presence of one genetic variant might predict that the specific protein it codes for is unable to break down a particular medication. This could potentially lead to increased drug levels in your body and an increased risk of side effects. The presence of another genetic variant might predict the opposite: It might predict that the protein it codes for is breaking down a medication more rapidly than expected, which may decrease the drug's effectiveness.

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For example, citalopram is an antidepressant broken down by a protein called CYP2C19. with genetic variants that code for a version of this protein with a reduced ability to break down the drug may have an increased risk of side effects.

PGx is a form of personalized or precision medicine.

Currently, there are over 80 medications with prescribing recommendations based on PGx results, including treatments for depression, cancer and heart disease. There are commercially available PGx tests that patients can have sent directly to their doorstep with or without the involvement of a care professional. These direct-to-consumer PGx tests collect DNA from either a saliva sample or cheek swab that is then sent to the laboratory. Results can take anywhere from a few days to a few weeks depending on the company.

Some companies require a consultation with a health care provider, often a pharmacist or genetic counselor, who can facilitate a test order and discuss any medication changes once the results back.

Limitations of PGx testing

PGx testing will not be able to predict how you will respond to all medications for several reasons.

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First, most PGx tests do not look for every possible variant of every gene in the human genome. Instead, they look only at a limited number of genes and variants strongly linked to specific . PGx tests can predict how you will respond only to medications associated with the genes it tests for.

Some drugs are broken down in very complicated pathways entailing multiple proteins and byproducts, and the usefulness of PGx testing for them remains unclear. For example, the antidepressant bupropion has three major pathways involved in its and forms three active byproducts that can interact with other drugs or body processes. This makes predicting how you will respond to the drug much more challenging because there is more than one variable involved. In many cases, there also isn't conclusive data to confidently predict the general function of a protein and how it would affect your response to a drug.

The applicability of PGx test results is additionally limited by a lack of diversity of study participants. Typically, populations of European ancestry are overrepresented in clinical trials. An ongoing research initiative by the National Institutes of Health called the All of Us Research Program aims to address this issue by collecting genetic samples from people of diverse backgrounds.

The All of Us research program seeks to conduct research that is more representative of a diverse population.

Another limitation of direct-to-consumer PGx tests is that they can predict drug response based only on your genetics. Lifestyle and environmental factors such as your age, liver or kidney function, tobacco use, drug interactions and other diseases can heavily influence how you may respond to medication. For example, leafy greens with high amounts of vitamin K can lower the effectiveness of the blood thinner warfarin. But PGx tests don't take these factors into account.

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Finally, your PGx results may predict that you may respond to medications differently, but this does not guarantee that the medication won't have its intended effect. In other words, PGx testing is predictive rather than deterministic.

Risks of PGx testing

PGx testing carries the risk of not telling the whole story of drug response. If variations within the gene are not found, the testing company often assumes the proteins those genes code for function normally. Because of this assumption, someone carrying a rare or unknown variant may inaccurate results.

It may be tempting for some people to see their results and want to change their dose or discontinue their medications. However, this can be dangerous. Abruptly stopping some medications may cause withdrawal effects. Never change the way you take your medications without consulting your pharmacist and physician first.

Sharing your PGx test results with all the clinicians involved in your care can help prevent medication failure and improve safety. Pharmacists are increasingly trained in pharmacogenomics and can serve as a resource to address medication-related questions or concerns.

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PGx tests that are not authorized by the Food and Drug Administration cannot be clinically interpreted and therefore cannot be used to inform prescribing. Results from these tests should not be added to your medical record.

Benefits of PGx testing

Direct-to-consumer PGx testing can empower patients to advocate for themselves and be an active participant in their health care by increasing access to and knowledge of their genetic information.

Patients' knowledge of their PGx genetic profile has the potential to improve treatment safety. For example, a 2023 study of over 6,000 patients in Europe found that those who used their PGx results to guide medication therapy were 30% less likely to experience adverse drug reactions.

Most PGx test results stay valid throughout a patient's , and retesting is not needed unless additional genes or variants need to be evaluated. As more research on gene variants is conducted, prescribing recommendations may be updated.

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Overall, genetic information from direct-to-consumer PGx tests can help you collaborate with health care professionals to select more effective medications with a lower risk of side effects.The Conversation

Kayla B. Rowe, Fellow in Clinical Pharmacogenomics, University of Pittsburgh; Lucas Berenbrok, Associate Professor of Pharmacy and , University of Pittsburgh, and Philip Empey, Associate Professor of Pharmacogenomics, University of Pittsburgh

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Excavating data from digs done decades ago and connecting with today’s communities

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theconversation.com – Emily Fletcher, Ph.D. Candidate in Archaeology, Purdue – 2024-06-18 07:39:20

Archaeologists excavate at the Gulkana Site in the 1970s.

Dr. William Workman Collection

Emily Fletcher, Purdue University

The ancestors of Alaska Native people began using local copper sources to craft intricate tools roughly 1,000 years ago. Over one-third of all copper objects archaeologists have found in this region were excavated at a single spot, named the Gulkana Site.

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This is the site I've studied for the past four years as a Ph.D. student at Purdue University. In spite of its importance, the Gulkana Site is not well known.

To my knowledge, it isn't mentioned in any museums. Locals, Alaska Native Ahtna people, who descend from the site's original inhabitants, might recognize the name, but they don't know much about what happened there. Even among archaeologists, little information is available about it – just a few reports and passing mentions in a handful of publications.

However, the Gulkana Site was first identified and excavated nearly 50 years ago. What gives?

Archaeology has a data management problem, and it is not unique to the Gulkana Site. U.S. federal regulations and disciplinary standards require archaeologists to preserve of their excavations, but many of these records have never been analyzed. Archaeologists refer to this problem as the “legacy data backlog.”

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As an example of this backlog, the Gulkana Site tells a story not only about Ahtna history and copperworking innovation, but also about the ongoing value of archaeological data to researchers and the public alike.

What happens after an excavation?

In the United States, most excavations, including those that have happened at the Gulkana Site, occur through a process called Cultural Resource Management. Since the 1960s, federal regulations in the U.S. have required archaeological excavations prior to certain development projects. Regulations also require that records of any finds be preserved for future generations.

One estimate suggests that this process has created millions of records in the legacy data backlog. Archaeological data is complex, and these records include many file formats, varying from handwritten maps to pictures and spatial data.

The problem is worst for datasets that were created before computers were in common use. Research suggests that archaeologists are biased toward digital datasets, which are easier to access and use with modern methods. Ignoring nondigital datasets means not only abandoning the product of decades of archaeological work, it also silences the human experiences those datasets are meant to preserve. Once a site is excavated, this data is the only way the people who lived there can tell their story.

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Archaeologists aren't sure how to resolve this problem. Many have been proposed, including the creation of new data repositories, making new use of existing datasets whenever possible, and increasing collaboration with other disciplines and with public stakeholders. One of the more creative solutions, the Vesuvius , recently made headlines for awarding its US$700,000 grand prize to a team that successfully used artificial intelligence to read ancient text.

Digital archaeology excavates old data

Of course, such a complicated problem has no single miracle cure. In my work with the Gulkana Site, I'm employing many of these suggestions through a newer form of archaeology that some researchers are calling digital public archaeology. It combines digital archaeology, which uses computers in archaeological research, with public archaeology, which honors the public's interest in the past.

For me, archaeology looks different than what people might expect. Instead of spending my days excavating in some fabulous location, my work involves being parked at a computer for hours on end. I dig through old information instead of digging up new information.

As a digital archaeologist, I apply modern methods like AI to bring new life to decades-old data about the Gulkana Site. I write software that converts 50-year-old handwritten excavation notes into a digital map that I can analyze with a computer.

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Although it is less glamorous, this work is arguably more important than excavation. Excavation is merely a data collection technique; on its own, it can't reveal much about a site. This is why there is still much to learn about the Gulkana Site, even though it was excavated decades ago.

Analysis is the way archaeologists learn about the past, and computers make more methods available to us than ever before. In my work, I use computational mapping techniques to study the copper artifacts recovered from the Gulkana Site. Studying where these objects were found will us understand if they were used by all people at the Gulkana Site or reserved for a select few.

Connecting archaeology to communities today

I am also a public archaeologist; I believe that the past is made meaningful through the people connected to it. This means that my study of the Gulkana Site would be insufficient were it conducted solely by me, alone at my computer 3,000 miles away from Alaska. Instead, I have designed my research in collaboration with descendants of the people who lived at the Gulkana Site to ensure my research value to them, not just to archaeologists.

In my research, this means embedding opportunities for youth involvement throughout my project. Each year, I travel to Alaska to host a course about archaeology, Ahtna history, and technology in collaboration with Ahtna leadership and the local school district.

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In the course, we take field trips to archaeological sites and the Ahtna Cultural Center. Kids learn about the artifacts found at the Gulkana Site and have an to make their own. Ahtna share cultural knowledge with students. At the end of the course, students integrate what they've learned into a video game about the Gulkana Site.

The goal of my research is to bring new life to the Gulkana Site through digital methods and outreach. My experiences demonstrate that even a site excavated 50 years ago can reveal more to help us better understand the past. Perhaps more importantly, it can also help the next generation gain experience with technological skills and connect with their heritage. Old archaeological data is still meaningful in the digital age – we just have to pay attention to it.The Conversation

Emily Fletcher, Ph.D. Candidate in Archaeology, Purdue University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Keeping astronauts healthy in space isn’t easy − new training programs will prepare students to perform medicine while thousands of miles away from Earth

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theconversation.com – Arian Anderson, Emergency Medicine Physician, of Colorado Anschutz Medical Campus – 2024-06-18 07:39:04

medicine professionals in consult with each other during a simulation exercise.

Katya Arquilla

Arian Anderson, University of Colorado Anschutz Medical Campus

In the coming decade, more people will go to space than ever before as human spaceflight enters a new era. NASA, the European Space Agency and other governmental agencies are partnering to develop crewed missions beyond the Moon. At the same time, these agencies are collaborating with private companies using new technologies to drive down the price of space exploration.

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Companies such as SpaceX, Blue Origin and Sierra Space have developed vehicles with reusable boosters, automated flight systems and lightweight materials to support these deep space missions. Some even have ambitions of their own to build private space stations, Moon bases or mining operations in the coming decades.

But as these technologies and partnerships rapidly make spaceflight more accessible, new challenges emerge. For one, maintaining the health and performance of an astronaut crew. My team of researchers and educators at the University of Colorado and others around the world are looking to address this issue.

A group of people in orange jumpsuits stand around a table, with a person laying on it.

With spaceflight set to expand, astronauts will need access to medical care over longer voyages and on commercial flights.

Katya Arquilla

Emerging medical challenges in space

NASA astronauts are some of the most accomplished people on the planet, and they're some of the healthiest. Astronauts undergo extensive medical and psychological testing that in one study disqualified 26% of final-round applicants. This rigorous screening and testing effectively limits the chance of a medical occurring during a mission.

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But as spaceflight becomes more accessible, astronaut crews on commercial missions will likely make up the majority of space travelers in the coming years. Private missions will be short and stay in a close orbit around Earth in the near term, but private crews will likely have less training and more chronic medical conditions than the professional astronauts currently living and working in space.

While experiments aboard the International Space Station have extensively studied the normal physiological changes occurring to the human system in weightlessness, there is limited to no data about how common chronic diseases such as diabetes or high blood pressure behave in the space environment.

Mars, shown from space.

During Mars missions, astronauts will be away from Earth for long periods of time, with limited access to medical resources.

CU/LASP EMM/EXI ITF/Kevin M. Gill, CC BY

This industry boom is also creating opportunities for long-duration missions to the Moon and Mars. Because of the length of missions and the distance from Earth, professional astronauts on these missions will experience prolonged weightlessness, leading to bone and muscle loss, communication delays of a few seconds up to 40 minutes, and extreme isolation for months to years at a time.

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Crews must function autonomously, while being exposed to new hazards such as lunar or Martian dust. Because of the fuel required for these missions, resources will be limited to the lowest mass and volume possible.

As a result, mission planners will need to make difficult decisions to determine what supplies are truly necessary in advance, with limited or unavailable resupply opportunities for food, and medicine. In space, for example, radiation and humidity inside a spacecraft can cause medications to deteriorate more quickly and become unavailable or even toxic to crew members.

Crews on the space station have access to a flight surgeon at Mission Control to help manage medical care in the same way telehealth is used on Earth. Crews on distant planets, however, will need to perform medical care or procedures autonomously.

In the event of a medical emergency, crews may not be able to evacuate to Earth. Unlike the space station, where medical evacuations to Earth can occur in less than 24 hours, lunar evacuations may take weeks. Evacuations from Mars may not be possible for months or even years.

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Put simply, the current approaches to medical care in spaceflight will not meet the needs of future commercial and professional astronauts. Researchers will need to develop new technologies and novel training approaches to prepare future providers to treat medical conditions in space.

The current in space medicine are either experts in aerospace engineering or in medicine, but rarely do experts have formal training or a complete understanding of both fields. And these disciplines often can't speak each other's language both literally and figuratively.

Training the next generation

To meet the evolving demands of human spaceflight, educators and universities are looking to develop a way to train specialists who understand both the limitations of the human body and the constraints of engineering design.

Some schools and hospitals, such as the University of Texas Medical Branch, have residency training programs for medical school graduates in aerospace medicine. Others, such as UCLA and Massachusetts General Hospital, have specialty training programs in space medicine, but these currently target fully trained emergency medicine physicians.

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My team at the University of Colorado has created a program that integrates human physiology and engineering principles to train medical to think like engineers.

Two domed tents connected by long tubes, in the desert.

The University of Colorado brings students to the desert to simulate a lunar base. Students work together to solve simulated medical issues that might occur during a space mission.

Katya Arquilla

This program aims to help students understand human health and performance in the spaceflight environment. It approaches these topics from an engineering design and constraints perspective to find to the challenges astronauts will face.

One of our most popular classes is called Mars in Simulated Surface Environments. This class puts students through engineering and medical scenarios in a simulated Mars environment in the Utah desert. Students deal with the challenges of working and providing care while wearing a spacesuit and on a desolate Mars-like landscape.

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The stress of the simulations can feel real to the students, and they learn to apply their combined skill sets to care for their fellow crew members.

Educational programs like these and others aim to create cross-trained specialists who understand both patient care and the procedural nature of engineering design and can merge the two, whether for space tourists in orbit or as a pioneer to the surface of another planet.

A new period of spaceflight is here, and these programs are already training experts to make space accessible and safe.The Conversation

Arian Anderson, Emergency Medicine Physician, University of Colorado Anschutz Medical Campus

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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The Hubble telescope has shifted into one-gyro mode after months of technical issues − an aerospace engineering expert explains

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theconversation.com – Panagiotis Tsiotras, Professor of Aerospace Engineering, Georgia Institute of Technology – 2024-06-17 07:13:24

The Hubble Telescope is nearing its 35th birthday.

NASA via AP

Panagiotis Tsiotras, Georgia Institute of Technology

Imagine keeping a laser beam trained on a dime that's 200 miles away. Now imagine doing that continuously for 24 hours, while riding a merry-go-round. Seem difficult? Well, that's basically what the Hubble Space Telescope does.

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After months of technical issues, NASA announced June 4 that Hubble would shift into one-gyroscope mode. This essentially means that the telescope will have to rely on just one of the several gyroscopes – devices that measure an object's orientation in space – it normally uses to track and follow objects in space.

Named after astronomer Edwin Hubble, the Hubble telescope launched in 1990 into low Earth orbit. Here, it's above Earth's atmosphere, which interferes with the observations from Earth-based telescopes. During its three decades of operation, it has provided us with stunning pictures of distant galaxies and scientists to look closer to the beginning of the universe.

Hubble takes clear, high-resolution pictures of billions of light years away. To collect enough photons – light “particles” – for a high-quality picture, it essentially acts as a very low-speed camera. It keeps its aperture – that is, the opening in the lens that lets light pass through – open for up to 24 hours to take a single picture.

Anyone who has taken a at a low shutter speed knows how difficult it is to avoid ending up with a blurry image. Hubble takes this to an extreme. It needs to stay pointed at the same distant point in space with an accuracy within a few milliarcseconds – where one milliarcsecond equals one 3,600,000th of a degree – for up to 24 hours. And it needs to keep this accuracy while orbiting the Earth at 17,000 miles per hour (27,000 kilometers per hour) through extreme heat and cold.

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To keep track of its target and generate clear pictures, Hubble uses what aerospace engineers like me call attitude control . All spacecraft and aircraft have an attitude control system to them point in the right direction.

What's a gyro, anyway?

An attitude control system consists of a suite of sensors measuring the orientation of the spacecraft, a set of actuators – thrusters, reaction wheels or control moment gyroscopes – that move the spacecraft around, and a flight computer. The flight computer takes the measurements from the sensors and generates the commands for the actuators.

A diagram of the Hubble, showing three boxes labeled gyros, three labeled fine guidance sensors and two labeled reaction wheels in its interior.

The gyros work in tandem with fine guidance sensors and reaction wheels to control the telescope's orientation in space.

NASA/STSci

A gyroscope is a device that measures an object's attitude, or orientation in space. In other words, it measures how much the object has rotated from some fixed point. For Hubble to know where it's pointing to take a picture, it has to know where it is in space. It needs at least three gyros – one per axis.

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Hubble initially had six gyros: three main ones and three more as extras. But after more than 30 years in orbit, four of the gyros have failed from complications related to aging.

From the two remaining gyros, NASA has reserved one as a backup, so Hubble is now operating with a single gyro. But if you need at least three gyros – one per axis – to know where you are, how can Hubble figure out where it is with only one gyro?

One of Hubble's gyroscopes.

The clever answer that NASA engineers came up with is actually very simple. You can use other sensors on the telescope, such as magnetometers and star sensors, to make up for the lack of gyros.

Gyro stand-ins

Magnetometers measure Earth's local magnetic field, which scientists understand pretty accurately. You can use the magnetometers to get a rough idea of the attitude with respect to the known magnetic field direction, pretty much the same way you use a compass. A three-axis magnetometer can take measurements of the strength and direction of the Earth's magnetic field as the satellite moves along its orbit to find its orientation in space.

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Or you can use star trackers or sun sensors, which are much more accurate than magnetometers. These sensors use a map of the sky and align what they see with what's on the map to figure out where they are pointing.

By combining the star trackers, sun sensors, magnetometers and a single gyro, Hubble can maintain a pointing accuracy that is very close to the three-gyro configuration – although the one-gyro configuration will limit how fast Hubble can track objects in space.

Hubble has one of the most accurate pointing attitude control systems ever built, and it has provided people with stunning pictures of the early universe. But losing all but two gyros is just another reminder that Hubble's days are numbered.

Hubble's successor, the James Webb Space Telescope, launched on Dec. 25, 2021. It is stationed 1,000,000 miles (1,609,344 km) away from Earth at what is called the second Lagrange point (L2).

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At this point, the telescope, the Earth and the Sun are always aligned, and the telescope's protective sun shield blocks the Sun's rays. This feature allows its infrared camera to operate at chilly temperatures to much better-quality pictures.

While the long-enduring Hubble's discoveries opened the universe to astronomers, Webb will allow us to look deeper into the cosmos than ever before.The Conversation

Panagiotis Tsiotras, Professor of Aerospace Engineering, Georgia Institute of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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