In Vivo Time-Resolved Fluorescence Detection of Liver Cancer Supported by Machine Learning.

Objectives: One of the widely used optical biopsy methods for monitoring cellular and tissue metabolism is time-resolved fluorescence. The use of this method in optical liver biopsy has a high potential for studying the shift in energy-type production from oxidative phosphorylation to glycolysis and changes in the antioxidant defense of malignant cells. On the other hand, machine learning methods have proven to be an excellent solution to classification problems in medical practice, including biomedical optics.

Detection of NADH and NADPH levels in vivo identifies shift of glucose metabolism in cancer to energy production.

Profound changes in the metabolism of cancer cells have been known for almost 100 years, and many aspects of these changes have continued to be actively studied and discussed. Differences in the results of various studies can be explained by the diversity of tumours, which have differing processes of energy metabolism, and by limitations in the methods used. Here, using fluorescence lifetime needle optical biopsy in a hepatocellular carcinoma (HCC) mouse model and patients with HCC, we measured reduced nicotinamide adenine dinucleotide (NADH) and reduced nicotinamide adenine dinucleotide phosphate (NADPH) in control liver, and in HCC tumours and their adjacent regions.

Sampling volume assessment for wearable multimodal optical diagnostic device.

The process and results of numerical Monte Carlo simulation of optical radiation propagation in laser Doppler flowmetry (LDF) and fluorescence spectroscopy (FS) channels of a wearable diagnostic multimodal device are described in this paper. To achieve the goal, a multilayer skin model with different parameters of blood and melanin content and different distances between sources and radiation receivers was designed. The changes in the sampling (diagnostic) volume depending on the anatomical features of the biological tissues, as well as on the technical parameters of the device were shown.

Digital diaphanoscopy of maxillary sinus pathologies supported by machine learning.

Maxillary sinus pathologies remain among the most common ENT diseases requiring timely diagnosis for successful treatment. Standard ENT inspection approaches indicate low sensitivity in detecting maxillary sinus pathologies. In this paper, we report on capabilities of digital diaphanoscopy combined with machine learning tools in the detection of such pathologies.

Laser-induced singlet oxygen selectively triggers oscillatory mitochondrial permeability transition and apoptosis in melanoma cell lines.

Singlet oxygen (O) is an electronically excited state of triplet oxygen which is less stable than molecular oxygen in the electronic ground state and produced by photochemical, thermal, chemical, or enzymatic activation of O. Although the role of singlet oxygen in biology and medicine was intensively studied with photosensitisers, using of these compounds is limited due to toxicity and lack of selectivity. We generated singlet oxygen in the skin fibroblasts and melanoma cell lines by 1267 nm laser irradiation.

Fluorescence lifetime needle optical biopsy discriminates hepatocellular carcinoma.

This work presents results of in vivo and in situ measurements of hepatocellular carcinoma by a developed optical biopsy system. Here, we describe the technical details of the implementation of fluorescence lifetime and diffuse reflectance measurements by the system, equipped with an original needle optical probe, compatible with the 17.5G biopsy needle standard.

Interaction of Mitochondrial Calcium and ROS in Neurodegeneration.

Neurodegenerative disorders are currently incurable devastating diseases which are characterized by the slow and progressive loss of neurons in specific brain regions. Progress in the investigation of the mechanisms of these disorders helped to identify a number of genes associated with familial forms of these diseases and a number of toxins and risk factors which trigger sporadic and toxic forms of these diseases. Recently, some similarities in the mechanisms of neurodegenerative diseases were identified, including the involvement of mitochondria, oxidative stress, and the abnormality of Ca signaling in neurons and astrocytes.

Assessment of Mitochondrial Membrane Potential and NADH Redox State in Acute Brain Slices.

Brain is one of the most energy-demanding organs. Energy in the form of ATP is produced in brain cells predominantly in oxidative phosphorylation coupled to mitochondrial respiration. Any alteration of the mitochondrial metabolism or prolonged ischemic or anoxic conditions can lead to serious neurological conditions, including neurodegenerative disorders.

Optical Diagnostics of the Maxillary Sinuses by Digital Diaphanoscopy Technology.

The work is devoted to the development of a scientific and technical basis for instrument implementation of a digital diaphanoscopy technology for the diagnosis of maxillary sinus inflammatory diseases taking into account the anatomical features of patients (differences in skin structure, skull bone thickness, and sinus size), the optical properties of exercised tissues, and the age and gender characteristics of patients. The technology is based on visualization and analysis of scattering patterns of low-intensity radiation as it passes through the maxillary sinuses. The article presents the experimental data obtained using the digital diaphanoscopy method and the results of numerical simulation of the optical radiation passage through the study area.

Interaction of Oxidative Stress and Misfolded Proteins in the Mechanism of Neurodegeneration.

Aggregation of the misfolded proteins β-amyloid, tau, huntingtin, and α-synuclein is one of the most important steps in the pathology underlying a wide spectrum of neurodegenerative disorders, including the two most common ones-Alzheimer's and Parkinson's disease. Activity and toxicity of these proteins depends on the stage and form of aggregates. Excessive production of free radicals, including reactive oxygen species which lead to oxidative stress, is proven to be involved in the mechanism of pathology in most of neurodegenerative disorders.

Multimodal Optical Diagnostics of the Microhaemodynamics in Upper and Lower Limbs.

The introduction of optical non-invasive diagnostic methods into clinical practice can substantially advance in the detection of early microcirculatory disorders in patients with different diseases. This paper is devoted to the development and application of the optical non-invasive diagnostic approach for the detection and evaluation of the severity of microcirculatory and metabolic disorders in rheumatic diseases and diabetes mellitus. The proposed methods include the joint use of laser Doppler flowmetry, absorption spectroscopy and fluorescence spectroscopy in combination with functional tests.

Optical probe pressure effects on cutaneous blood flow.

The variation of blood flow characteristics caused by the probe pressure during noninvasive studies is of particular interest within the context of fundamental and applied research. It has been shown previously that the weak local pressure induces vasodilation, whereas the increased pressure is able to stop the blood flow in the compressed area, as well as to significantly change optical signals.The blood flow oscillations measured by laser Doppler flowmetry (LDF) characterize the functional state of the microvascular system and can be used for noninvasive diagnostics of its abnormality.

Multimodal optical measurement for study of lower limb tissue viability in patients with diabetes mellitus.

According to the International Diabetes Federation, the challenge of early stage diagnosis and treatment effectiveness monitoring in diabetes is currently one of the highest priorities in modern healthcare. The potential of combined measurements of skin fluorescence and blood perfusion by the laser Doppler flowmetry method in diagnostics of low limb diabetes complications was evaluated. Using Monte Carlo probabilistic modeling, the diagnostic volume and depth of the diagnosis were evaluated.