MOSCOW, October 4, Vladislav Strekopytov. Scientists from Tomsk State University (TSU) have developed a painless express diagnosis of health using a drop of blood or exhaled air. In just a few minutes, markers of dangerous diseases, including incipient cancer, can be identified.
Human Molecular Profile
Doctors say that correct and timely diagnosis is the key to successful treatment. It is especially important to quickly and accurately make a diagnosis in such critical conditions as a heart attack or stroke, when minutes literally count. And in the case of oncology, the main task is not to miss the disease at an early stage.
The idea that the composition of blood, urine and saliva reflects the state of human health has existed since ancient times. However, only technological progress in recent decades has made it possible to quantitatively measure metabolic products contained in biological fluids — metabolites. A separate scientific field has emerged — metabolomics, within which scientists study the molecular signs of various processes in the body, including pathological ones.
Based on mathematical modeling, scientists from the TSU Laboratory of Laser Molecular Imaging and Machine Learning calculated multicomponent molecular profiles characteristic of certain diseases. Then we produced mixtures of marker molecules in a certain concentration for each profile from known compounds, trained a neural network on their example, and tested the results obtained on real samples of biological fluids and tissues taken from patients.
«Our diagnostic method is based on component analysis of tissues , biological fluids or exhaled air on biomarker molecules,» says project participant, laboratory employee Denis Vrazhnov. “For this we use modern instruments — a Raman microscope, a terahertz spectrometer, gas analyzers.»
Diagnostics using molecular profiles is much more accurate than using individual marker molecules, and the use of artificial intelligence in data interpretation reduces the risk of errors to a minimum. In the future, the entire analysis procedure can be performed completely automatically, according to the authors of the new method.
How it works, journalists were shown during an excursion to the laboratory, organized as part of the Popular Science Tourism initiative of the Decade of Science and technologies, which includes visiting the sites of the national project «Science and Universities».
Find cancer with a drop of blood
Directly monitoring metabolic changes in the human body is very difficult. Some — for example, the breakdown of hormones — occur very quickly, others are realized at the intracellular level and are not available for direct observation. Therefore, most functional diagnostic methods are based on indirect data.
Thus, during ultrasound examinations (ultrasound), the doctor analyzes the picture created by sound waves as they pass through tissues and organs. A radiograph is a projection of x-rays that shows the internal anatomical structure. The spectral characteristics of light can be used to judge the molecular composition of tissues or liquids.
“Looking at the spectral profile, we can tell what reactions occur in the body, how it reacts to external stimuli, viruses, bacteria,” explains the scientist.
In experiments conducted on one of the most sensitive instruments, a confocal Raman spectrometer, researchers found that the profile shape can be used to track, and at a very early stage, the development of cancer: skin cancer (melanoma) and glioma — one of the most aggressive forms of cancer brain The results obtained were confirmed using another device — a terahertz spectrometer.
Glioma is most often discovered in advanced stages, when the patient develops symptoms such as severe headaches and nausea. The diagnosis is confirmed using an MRI of the head. Now the disease can be detected by a drop of blood. The proposed method has passed the stage of pilot testing on animals, and now experts are moving on to research on human biomaterials.
“We studied how the molecular composition of brain tissue changes in mice that were injected with cancer cells, as a result of which they developed glioma,” says Vrazhnov. “It turned out that a healthy brain has one profile, while a patient’s brain has a completely different one. Moreover, we found that it is different for tumor and inflammation.»
This solves another diagnostic problem. It is known that tumor development is often, but not always, preceded by inflammation. Analysis of molecular profiles makes it possible to highly reliably identify metabolites of pre-cancer inflammation in a blood serum sample and notice the onset of brain tumor development much earlier than is currently being done.
The authors are confident that it will be possible to detect not only glioma, but also other types of tumors. All data on blood changes in various oncological diseases are now entered into an electronic database, which will be accessed by artificial intelligence during the analysis process.
Diagnosis by breathing
Researchers from TSU have learned to obtain a molecular profile not only from blood, but also from the composition of the air exhaled by a person. To do this, they improved, using machine learning methods, the method of chemical analysis on another device — a gas analyzer.
“Changes in metabolism are reflected in the composition of the blood that washes the lungs,” explains the scientist. “Due to gas exchange, markers molecules that accompany some pathological process enter the exhaled air, and we capture them using a gas analyzer.»
At the same time, what is important for diagnostics is not so much the set of analyzed compounds itself (as a rule, it is standard: nitrogen oxides, carbon dioxide, carbon monoxide, ammonia and some other volatile hydrocarbons), but rather the ratio of their concentrations. For example, elevated ammonia levels are a good marker of diabetes. Using molecular profiles, you can recognize Covid, tuberculosis, and heart disease.
“All these diseases change the composition of exhaled air,” notes the researcher. “Our device operates in a very wide range and can “catch” a large number of marker molecules.”< br />
The method has already been tested in clinical settings on patients with tuberculosis. Tests in groups of volunteers with primary myocardial infarction also showed good results.
Molecular psychosomatics
Recently, laboratory scientists tried to diagnose mental illness using a gas analyzer. To do this, we collected samples of exhaled air from patients with depression, schizophrenia, and bipolar disorder, compared the results with the control group and identified chemical features characteristic of each diagnosis.
“When we conducted the research, we were asked to check whether markers of depression were preserved in the exhaled air of those who had already undergone treatment,” says Vrazhnov. “Usually, the profile of those who were cured returned to normal. But in some patients in the group that was already being prepared for discharge, the spectral characteristics have not changed. This suggests that the treatment was insufficient and the disease can quickly return.»
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The proposed method, its authors believe, can become the first objective tool for monitoring the effectiveness of treatment in psychiatry, where traditionally they are accustomed to relying only on the subjective opinion of the observing doctor.
The laboratory staff conducted the most unusual experiment in one of the city's cinemas. Assuming that the set of chemicals produced by the body depends, among other things, on the general psychological state of a person, they collected air samples in the cinema during the screening of an action-packed film, analyzed them and obtained a profile of “collective stress”, which, as the plot progressed and tension increased, became more and more pronounced.
Researchers hope that rapid diagnostics using molecular profiles will be widely used in practice. In addition to medicine, it can be used in forensics, inspection and control systems, as well as in other areas.