Possibilities of Laser Spectroscopy Methods for Prediction of the Radiotherapy Results

In this paper, possibilities of laser fluorescence spectroscopy to predict the reactions of the oral cavity cancer to radiation treatment are considered. A theoretically substantiated assumption about the link between the tumor’s consumption of an exogenous photosensitizer and its radioresistance is proposed. The first experience with the use of the Radahlorin photosensitizer is described; preliminary results of the 5 patients study are presented. As a result different photosensitizer consumptions versus different treatment outcomes are discussed. Keywords: laser fluorescence spectroscopy, photosensitizer, oral cavity cancer, radiotherapy, cross-resistanc

Assessment of Gold Nanoparticles Uptake in Tissues of Female Mice and Their Offspring Using Neutron Activation Analysis

Only AbstractThe uptake of gold in different tissues of female mice and their offspring after prolonged oral administration of gold nanoparticles to the females during pregnancy and lactation was investigated. Gold content in different organs was determined using neutron activation analysis. The highest content of gold was accumulated in kidneys followed by liver, lungs, blood and brain. Accumulation of gold in brain confirms ability of nanoparticles to pass through placental and blood-brain barriers. The average specific mass content of gold which crossed the blood-brain barrier was 3.8 ng/g (for female) and 1.1 ng/g (for offspring). The results are important for research on developmental and reproductive toxicity and safety of nanomaterials

Лазерная флуоресцентная спектроскопия и оптическая тканевая оксиметрия в диагностике фиброза кожи

There are currently no effective measures to combat fibrosis in modern medical practice. One of the reasons for that is the late diagnosis associated with the lack of available clinical biomarkers and effective methods of non-invasive detection of the process. Fibrosis of the skin is characterized by fibrosis of the dermis, underlying tissues and is represented by a wide range of nosologies. Scleroderma and scars are of the greatest interest for the study. Skin changes in the development of bleomycin-induced fibrosis was studied in the experimental model using laser fluorescence spectroscopy and optical tissue oximetry. A significant increase in the rates of endogenous fluorescence of porphyrins, caused by inflammation and hypoxia, was detected at 7 and 21 days. An increased intensity of endogenous collagen fluorescence and a decreased specific oxygen uptake due to excess accumulation of the extracellular matrix were recorded on the 21st day after bleomycin treatment. Synchronous measurements of the collagen fluorescence and the specific oxygen uptake allowed to correlate the obtained data and the phases of the fibrogenic response described morphologically. The results allow to judge the severity of inflammation and hypoxia in the process of the fibrosis development. The objective and quantitative nature of the recorded parameters makes it possible to develop criteria for diagnosing the phases of fibrosis development.В современной медицинской практике нет эффективных мер борьбы с фиброзом. Одна из причин – поздняя диагностика, связанная с отсутствием доступных клинических биомаркеров и эффективных методов неинвазивного обнаружения этого процесса. Фиброзирующие заболевания кожи характеризуются фиброзом дермы, подлежащих тканей и представлены широким спектром нозологий. Наибольший интерес для изучения представляют склеродермия и рубцы кожи. На экспериментальной модели методами лазерной флуоресцентной спектроскопии и оптической тканевой оксиметрии изучены изменения кожи в рамках развития блеомицин-индуцированного фиброза. Выявлен достоверный рост показателей эндогенной флуоресценции порфиринов на 7 и на 21 сут, вызванный воспалением и гипоксией. Зафиксированы повышение интенсивности эндогенной флуоресценции коллагена и снижение показателей удельного потребления кислорода на 21 сут исследования, связанные с избыточным накоплением межклеточного матрикса. Синхронные измерения флуоресценции коллагена и удельного потребления кислорода позволили провести корреляцию с фазами фиброгенного ответа, описанного морфологически. Полученные результаты позволяют судить о выраженности воспаления и гипоксии в процессе развития фиброза. Объективный и количественный характер регистрируемых параметров дает возможность разработки критериев для диагностики фаз развития фиброза

A new look at fundamentals of the photometric light transport and scattering theory. Part 3:Bridges to multi-dimensional problems

In previous two parts of the article, one-dimensional (1D) scattering processes were taken into detailed consideration. All main typical 1D scattering problems of different complexities were discussed and solved using different approaches. It gave the opportunity to find ways to improve the theory, two-fluxes Kubelka — Munk approach, in particular. It was shown that scattering and absorption processes inside the light-scattering medium are not independent, so the formulation of first coefficients of transport differential equations as the simplest sum of scattering and absorption coefficients is wrong. Inaccuracy in this formulation leads to inaccuracies in results. In this final part of the article, as a completion, the analysis of some spatial light-scattering problems, mainly two-dimensional (2D) problems as the simplest multidimensional problems for consideration, is presented. The detailed analysis of several important 2D approximations, such as a pure backscattering approximation, single-scattering one for a pencil-like beam, and an orthogonal-scattering approach opens the way to have a new look at several nuances of formulation of the 2D or 3D initial transport equations, as well. For example, a new unknown form of the radiative transport equation of the fourth-order is proposed for the case of the orthogonal scattering approach.</p

A new look at fundamentals of the photometric light transport and scattering theory. Part 3:Bridges to multi-dimensional problems

In previous two parts of the article, one-dimensional (1D) scattering processes were taken into detailed consideration. All main typical 1D scattering problems of different complexities were discussed and solved using different approaches. It gave the opportunity to find ways to improve the theory, two-fluxes Kubelka — Munk approach, in particular. It was shown that scattering and absorption processes inside the light-scattering medium are not independent, so the formulation of first coefficients of transport differential equations as the simplest sum of scattering and absorption coefficients is wrong. Inaccuracy in this formulation leads to inaccuracies in results. In this final part of the article, as a completion, the analysis of some spatial light-scattering problems, mainly two-dimensional (2D) problems as the simplest multidimensional problems for consideration, is presented. The detailed analysis of several important 2D approximations, such as a pure backscattering approximation, single-scattering one for a pencil-like beam, and an orthogonal-scattering approach opens the way to have a new look at several nuances of formulation of the 2D or 3D initial transport equations, as well. For example, a new unknown form of the radiative transport equation of the fourth-order is proposed for the case of the orthogonal scattering approach.</p

A new look at fundamentals of the photometric light transport and scattering theory. Part 2:One-dimensional scattering with absorption

In the first part of the article, one-dimensional (1D) pure scattering processes were taken into detailed consideration. It allowed to prove that the scattering coefficient is not just a real optical property of a turbid medium, but also is a parameter of the mathematical description of the problem. It depends on the approximation, which is applied to solve the problem. Therefore, in different approaches it can vary. More real and close to realistic practical problems are scattering problems with absorption. This second part of the article describes the 1D scattering problems with absorption. It is shown, that scattering and absorption processes inside the light-scattering medium are not independent in most cases, so a formulation of the first coefficients of initial differential equations, which mathematically describe the problem, as the simplest superposition of scattering and absorption coefficients is wrong. Inaccuracy in this formulations leads to inaccuracies in final results. More correct formulation, for example, in application to the classical two-flux Kubelka - Munk (KM) approach, which is a good 1D limit for the radiative transport equation, allows one to obtain the exact analytical solution for boundary radiant fluxes (backscattered and transmitted ones), contrary to the classic KM approximation. In addition, it leads to the need for revision of definitions of a number of basic terms in the general radiative transport theory, especially of the albedo, which plays a key role in Monte-Carlo simulations.</p