A new diagnostic device created by a collaborative team of UA engineers and scientists may significantly reduce the amount of time necessary to diagnose tissue infections
When a patient arrives at a hospital with a serious infection, doctors have precious few minutes to make an accurate diagnosis and prescribe treatment accordingly. Doctors’ ability to act quickly and correctly not only makes a difference to the patient’s outcome, it determines whether the infection spreads to other patients in the clinic, and can even contribute to the development of drug-resistant bacteria.
Luckily for patients and doctors alike, a new diagnostic device created by collaborative team of UA engineers and scientists may significantly reduce the amount of time necessary to diagnose tissue infections. The device’s novel approach to molecular diagnostics, called DOTS qPCR, is faster, more efficient and less expensive than alternatives currently being used in clinics. The work is described online in the journal Science Advances.
“We have developed a completely different type of system than what exists out on the market,” said Dustin Harshman, a former graduate student in the Biomedical Engineering Graduate Interdisciplinary Program, currently a scientist at Ventana Medical Systems. “We want to see physicians get diagnostic information more rapidly and prescribe better initial therapies.”
Pathogens and infectious diseases are typically detected using a technique called polymerase chain reaction, or PCR. The method involves rapidly heating and cooling DNA molecules from a biological sample in a process called thermal cycling. This results in the amplification of the target DNA into millions, and even billions of copies. Scientists and physicians can then use the copies to identify the type of pathogen causing the infection. The problem is that most PCR tests can take up to an hour or more, and a physician’s decision-making window is typically less than ten minutes.
“With DOTS qPCR we are able to detect amplification and identify the infection after as few as 4 thermal cycles, while other methods are working with between 18 and 30,” said Jeong-Yeol Yoon, a professor in the Department of Agricultural and Biosystems Engineering and a joint appointment in the Department of Biomedical Engineering. “We can get from sample to answer in as little as 3 minutes and 30 seconds.”
DOTS qPCR, invented by Yoon and his research group, stands for droplet-on-thermocouple silhouette real-time PCR. The technology relies on the measurement of subtle surface tension changes at the interface of a water droplet suspended in an oil medium. The water droplet, which contains the target DNA to be amplified, is moved along a heat gradient in the oil to begin the chain reaction. As more copies of the target DNA are produced, they move towards the oil-water interface, resulting in measurable changes in surface tension. Remarkably, the size of the droplet can be measured using a smartphone camera, providing a method to observe the course of the reaction in real time.
“What’s interesting about the way we approached this is that we’ve developed a deep understanding of what’s happening at a molecular level in our system,” said Harshman, who initially struggled to determine how to monitor the course of the reaction. “That kind of understanding gave us the ability to figure out why it was failing, and then leverage that failure as an advantage to create a completely new method.”
In addition to much faster diagnosis times, the system does not require samples to be completely free of other contaminants. This can save valuable time otherwise spent preparing samples for testing.
“The system still works with relatively dirty samples,” said Yoon. “We can use very minimal processing and still make the detection in a short time.”
Yoon emphasized that DOTS qPCR is inexpensive compared to its counterparts, which employ costly and time-intensive testing methods involving fluorescence detection, lasers and dark chambers.
“It’s easy to use, smartphone-integrated and saves money and labor using expensive equipment,” explained Yoon. “This technology has a lot of commercial potential, and we’d be happy to work with industry to bring it to market.”
People who have had an infection that made them so sick they had to be hospitalized may have IQs that are slightly lower than average, a new study suggests.
Researchers from the University of Copenhagen and Aarhus University in Denmark examined the hospital records of 190,000 Danish men born between 1974 and 1994. All the men took IQ tests at age 19, as part of the process of signing up for Denmark’s mandatory draft. The tests were designed to assess their logical, verbal, numerical and spatial reasoning.
After adjusting for factors known to track with people’s IQ scores, such as social conditions and the education levels of their parents, the researchers found that the average IQ score of the men who had been hospitalized for an infection before they took the IQ test — about 35 percent of the study cohort — were 1.76 points below the average of the men in the study who had not been hospitalized for an infection.
“Infections in the brain affected the cognitive ability the most, but many other types of infections severe enough to require hospitalization can also impair a patient’s cognitive ability,” study author Dr. Michael Eriksen Benrós, a researcher at the National Centre for Register-Based Research, said in a statement.
A crucial ‘on switch’ that boosts the body’s defences against infections has been successfully identified in new scientific research.
The breakthrough made by researchers at the University of Aberdeen and the University of Dundee could lead to the development of new drugs to enhance the body’s immune responses to attack, which could benefit people suffering from cancer and other serious conditions.
Their findings have been published in the Journal of Molecular and Cell Biology.
“We have shown that the cells which turn on our immune responses to defend against, for example, infectious diseases, require a particular protein to activate them in order to function properly,” explains Dr Martin-Granados formerly of the University of Aberdeen and now at Cambridge.
“This protein, or enzyme, (PTP1B) effectively acts as a kind of ‘on switch’ and if it is missing or dysfunctional in our body, we cannot mount effective immune responses to tumours or infections.”