Amid the ongoing COVID-19 health crisis caused by the SARS-CoV-2 virus and its multiple variants, tests to determine whether a person is infected or not have gained widespread recognition. One of the main assessment tools that health authorities in most countries rely on to detect the presence of COVID-19 virus is the Polymerase Chain Reaction test, better known by its abbreviation as PCR test.
Ever since it was approved for use in February 2020, the PCR has been the gold-standard test for diagnosing COVID-19 infection. The test involves taking a sample from the upper area in the nose and examining the specimen in the laboratory where it is tested for genetic material from the SARS-CoV-2 virus. Besides being accurate and reliable, the ability to conduct these tests easily by most countries has led to it gaining popularity around the world.
However, a major drawback to the PCR test is that it is relatively expensive, and results from the test could take time if the specimen needs to be sent to a distant laboratory for analysis. A more rapid test available to determine the presence of the virus is the antigen test or rapid antigen test that detects certain proteins in the virus. An antigen test, which is also available through at-home test kits, can produce results in minutes but tends to be less accurate than a PCR test.
Now, researchers at the University of Washington in the United States, have developed a new test for COVID-19 that they labeled tHarmony, which combines the speed of over-the-counter antigen tests with the accuracy of PCR tests that are processed in medical labs and hospitals.
The Harmony COVID-19 test is a diagnostic test that, like PCR tests for COVID-19, detects genetic material from the SARS-CoV-2 virus. But whereas conventional PCR tests can take several hours, the Harmony kit can provide results in less than 20 minutes for some samples and with similar accuracy.
The test was designed to be low-cost using ready-to-use reagents and simple enough to conduct so that it could be used anywhere, which would make this high-quality testing more accessible around the world.
The test uses a ‘PCR-like’ method to detect the presence of SARS-CoV-2 genetic material obtained through a nasal swab sample with the aid of a small, low-cost detector, which was also designed by the university researchers. A smartphone is then used to operate the detector and read the results. The detector can handle up to four samples at a time and would fit into a standard shoebox.
The recent rise in infections from new variants of the virus and the shortage in COVID-19 diagnostic tests in many places have highlighted the need for accurate and more rapid tests. Many at-home antigen kits for COVID-19, which detect pieces of the proteins the virus creates instead of its genetic material, are 80-85 percent accurate, though accuracy may drop with the Omicron variant, which harbors a relatively high number of mutations not found in other strains. PCR tests are generally 95 percent accurate or better, but require expensive equipment and often a long wait for results.
Initial results reported by the researchers show that the Harmony kit is 97 percent accurate for nasal swabs. The Harmony kit detects three different regions of the virus’ genome. If a new variant has many mutations in one region, the new test can still detect the other two. For example, it can detect the Omicron variant, which has dozens of mutations in the region of the genome that encodes the so-called spike protein.
Though tests based on PCR are highly accurate, a key limitation is that PCR tests require dozens of cycles of heating and cooling to detect genetic material in a sample. In contrast, the Harmony test sidesteps this issue by relying on a PCR-like method known as RT-LAMP (Reverse Transcription – Loop-Mediated Isothermal Amplification), which does not have the same stringent temperature-cycling requirements. Since the test operates at a constant temperature, it eliminates the time needed to heat and cool and usually gives results in about 30 minutes.
The researchers hope that initially the kits could be made available for use in clinics, as well as other settings with medical oversight, such as workplaces and schools, but later they aim to adapt the test for home use.
Exercise time determines health benefits
It has long been established that exercise improves overall health, but newer research has shown that the benefits of exercise to the body can vary depending on the time of the day that it is conducted.
However, scientists and doctors did not understand why exercising at different times of the day produced varying results. To gain a better understanding of this issue, a team of international researchers from the University of Copenhagen in Denmark, the Karolinska Institutet in Sweden, Helmholtz Munich in Germany, and from Texas A&M University and the University of California-Irvine in the United States, recently carried out a comprehensive collaborative study on this subject.
Results from the study show that based on the time of the day, different health-promoting signaling molecules are produced in the body in an organ-specific manner. These signals have a broad impact on health, influencing sleep, memory, and exercise performance, as well as on metabolic homeostasis, which is the self-regulating state of steady internal, physical, and chemical conditions maintained by living systems.
Scientists behind the study point out that a better understanding of how exercise affects the body at different times of day could help us to maximize the benefits of exercise for people, especially for those at risk of diseases, such as obesity and type 2 diabetes.
Nearly all cells in the body that come together to form tissues and organs in the body regulate their biological processes over 24 hours in what is often referred to as a circadian rhythm. This means that the sensitivity of different tissues to the effects of exercise changes depending on the time of day. Earlier research has confirmed that exercise timing according to our circadian rhythm can optimize the health-promoting effects of exercise.
To obtain a more detailed understanding of this effect, the team of international scientists conducted a range of experiments on mice that exercised either in the early morning or in the late evening. Blood samples and different tissues, including brain, heart, muscle, liver, and fat were collected and analyzed by mass spectrometry. This allowed the scientists to detect hundreds of different metabolites and hormone-signaling molecules in each tissue, and to monitor how they were changed by exercising at different times of the day.
Following their study, the international team came up with an ‘Atlas of Exercise Metabolism’ — a comprehensive map of signaling molecules induced by exercise that are present in different tissues following exercise at different times of the day.
Other insights from the study include a deeper understanding of how tissues communicate with each other, and how exercise can help to ‘realign’ faulty circadian rhythms in specific tissues. Faulty circadian clocks have been linked to increased risks of obesity and type 2 diabetes. The study also identified new exercise-induced signaling molecules in multiple tissues, which need further investigation to understand how they can individually or collectively influence health.
In a report on their study, the scientists said that the study not only showed how different tissues respond to exercise conducted at different times of the day but also proposed that these time-based exercise responses were interconnected to induce an orchestrated adaptation that controls systemic energy homeostasis in the body.
However, the scientists admitted that their study had several limitations, including that it was conducted on mice. Although mice share many common genetic, physiological, and behavioral characteristics with humans, they also have important differences. For example, mice are nocturnal, and the type of exercise was also limited to treadmill running, which can produce different results compared to high-intensity exercise. Finally, the impact of sex, age, and disease was not considered in the analysis.
The researchers behind the study hope that further research into the subject could help us gain a better understanding of how exercise if timed correctly, can help to improve various aspects of human health.