Pub Date : 2023-10-23DOI: 10.24931/2413-9432-2023-12-3-4-10
I. D. Romanishkin, T. A. Savelieva, A. Ospanov, K. G. Linkov, S. V. Shugai, S. A. Goryajnov, G. V. Pavlova, I. N. Pronin, V. B. Loschenov
The motivation for the present study was the need to develop methods of urgent intraoperative biopsy during surgery for removal of intracranial tumors. Based on the experience of previous joint work of GPI RAS and N.N. Burdenko National Medical Research Center of Neurosurgery to introduce fluorescence spectroscopy methods into clinical practice, an approach combining various optical-spectral techniques, such as autofluorescence spectroscopy, fluorescence of 5-ALA induced protoporphyrin IX, diffuse reflection of broadband light, which can be used to determine hemoglobin concentration in tissues and their optical density, Raman spectroscopy, which is a spectroscopic method that allows detection of various molecules in tissues by vibrations of individual characteristic molecular bonds. Such a variety of optical and spectral characteristics makes it difficult for the surgeon to analyze them directly during surgery, as it is usually realized in the case of fluorescence methods – tumor tissue can be distinguished from normal with a certain degree of certainty by fluorescence intensity exceeding a threshold value. In case the number of parameters exceeds a couple of dozens, it is necessary to use machine learning algorithms to build a intraoperative decision support system for the surgeon. This paper presents research in this direction. Our earlier statistical analysis of the optical-spectral features allowed identifying statistically significant spectral ranges for analysis of diagnostically important tissue components. Studies of dimensionality reduction techniques of the optical-spectral feature vector and methods of clustering of the studied samples also allowed us to approach the implementation of the automatic classification method. Importantly, the classification task can be used in two applications – to differentiate between different tumors and to differentiate between different parts of the same (center, perifocal zone, normal) tumor. This paper presents the results of our research in the first direction. We investigated the combination of several methods and showed the possibility of differentiating glial and meningeal tumors based on the proposed optical-spectral analysis method.
{"title":"Classification of intracranial tumors based on optical-spectral analysis","authors":"I. D. Romanishkin, T. A. Savelieva, A. Ospanov, K. G. Linkov, S. V. Shugai, S. A. Goryajnov, G. V. Pavlova, I. N. Pronin, V. B. Loschenov","doi":"10.24931/2413-9432-2023-12-3-4-10","DOIUrl":"https://doi.org/10.24931/2413-9432-2023-12-3-4-10","url":null,"abstract":"The motivation for the present study was the need to develop methods of urgent intraoperative biopsy during surgery for removal of intracranial tumors. Based on the experience of previous joint work of GPI RAS and N.N. Burdenko National Medical Research Center of Neurosurgery to introduce fluorescence spectroscopy methods into clinical practice, an approach combining various optical-spectral techniques, such as autofluorescence spectroscopy, fluorescence of 5-ALA induced protoporphyrin IX, diffuse reflection of broadband light, which can be used to determine hemoglobin concentration in tissues and their optical density, Raman spectroscopy, which is a spectroscopic method that allows detection of various molecules in tissues by vibrations of individual characteristic molecular bonds. Such a variety of optical and spectral characteristics makes it difficult for the surgeon to analyze them directly during surgery, as it is usually realized in the case of fluorescence methods – tumor tissue can be distinguished from normal with a certain degree of certainty by fluorescence intensity exceeding a threshold value. In case the number of parameters exceeds a couple of dozens, it is necessary to use machine learning algorithms to build a intraoperative decision support system for the surgeon. This paper presents research in this direction. Our earlier statistical analysis of the optical-spectral features allowed identifying statistically significant spectral ranges for analysis of diagnostically important tissue components. Studies of dimensionality reduction techniques of the optical-spectral feature vector and methods of clustering of the studied samples also allowed us to approach the implementation of the automatic classification method. Importantly, the classification task can be used in two applications – to differentiate between different tumors and to differentiate between different parts of the same (center, perifocal zone, normal) tumor. This paper presents the results of our research in the first direction. We investigated the combination of several methods and showed the possibility of differentiating glial and meningeal tumors based on the proposed optical-spectral analysis method.","PeriodicalId":37713,"journal":{"name":"Biomedical Photonics","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135414146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-23DOI: 10.24931/2413-9432-2023-12-3-25-35
V. E. Olyushin, K. K. Kukanov, A. S. Nechaeva, S. S. Sklyar, A. E. Vershinin, M. V. Dikonenko, A. S. Golikova, A. S. Mansurov, B. I. Safarov, A. Y. Rynda, G. V. Papayan
Literature review reflects the current status and development status of intraoperative photodynamic therapy in neurooncology and discusses the results of the most important studies on photodynamic therapy (PDT). We searched the Pubmed, EMBASE, Cochrane Library and eLibrary data-bases for publications published between January 2000 and December 2022. Found 204 publications in foreign sources and 59 publications in domestic editions, dealing with the issues of photodynamic therapy in neurooncology. An analysis of the literature has shown that intraoperative PDT in neurooncology is an important tool that contributes to increasing the radicality of the operation and local control. The basic rationale for the effectiveness of PDT lies in the study of the pathways leading to the complete devitalization of a malignant tumor, the study of the mechanisms of the local and systemic immune response. In addition, subcellular targets in PDT are determined by the properties of photosensitizers (PS). Second generation PSs have already been introduced into clinical practice. The effectiveness of PDT using photoditazine, 5-aminolevulinic acid has been demonstrated. The mechanisms of action and targets of these PS have been established. In Russia, a number of studies have repeatedly shown and proved the clinical effectiveness of PDT in groups of neurooncological patients with glial tumors and secondary metastatic tumors, but so far, the method has not been included in the clinical guidelines for the provision of high-tech neurosurgical care. There is certainly a need for further development of PTD techniques in neurooncology, especially in patients at high risk of recurrence and aggressive CNS tumors.
{"title":"Photodynamic therapy in neurooncology","authors":"V. E. Olyushin, K. K. Kukanov, A. S. Nechaeva, S. S. Sklyar, A. E. Vershinin, M. V. Dikonenko, A. S. Golikova, A. S. Mansurov, B. I. Safarov, A. Y. Rynda, G. V. Papayan","doi":"10.24931/2413-9432-2023-12-3-25-35","DOIUrl":"https://doi.org/10.24931/2413-9432-2023-12-3-25-35","url":null,"abstract":"Literature review reflects the current status and development status of intraoperative photodynamic therapy in neurooncology and discusses the results of the most important studies on photodynamic therapy (PDT). We searched the Pubmed, EMBASE, Cochrane Library and eLibrary data-bases for publications published between January 2000 and December 2022. Found 204 publications in foreign sources and 59 publications in domestic editions, dealing with the issues of photodynamic therapy in neurooncology. An analysis of the literature has shown that intraoperative PDT in neurooncology is an important tool that contributes to increasing the radicality of the operation and local control. The basic rationale for the effectiveness of PDT lies in the study of the pathways leading to the complete devitalization of a malignant tumor, the study of the mechanisms of the local and systemic immune response. In addition, subcellular targets in PDT are determined by the properties of photosensitizers (PS). Second generation PSs have already been introduced into clinical practice. The effectiveness of PDT using photoditazine, 5-aminolevulinic acid has been demonstrated. The mechanisms of action and targets of these PS have been established. In Russia, a number of studies have repeatedly shown and proved the clinical effectiveness of PDT in groups of neurooncological patients with glial tumors and secondary metastatic tumors, but so far, the method has not been included in the clinical guidelines for the provision of high-tech neurosurgical care. There is certainly a need for further development of PTD techniques in neurooncology, especially in patients at high risk of recurrence and aggressive CNS tumors.","PeriodicalId":37713,"journal":{"name":"Biomedical Photonics","volume":"50 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135414380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-23DOI: 10.24931/2413-9432-2023-12-3-16-20
A. M. Udeneev, N. A. Kalyagina, V. F. Reps, V. V. Kozlova, L. A. Pigunova, D. I. Pozdnyakov, A. S. Skobeltsin, V. B. Loschenov
The purpose of the work is to follow the dynamics of changes in fluorescent signals in the near-surface layers of tissue of injured areas of the back of laboratory animals, which will allow, by indirect evidence, to evaluate the information content of fluorescence diagnosis for subsequent possible diagnostic monitoring of photodynamic therapy of the spinal cord. The model animals were Wistar rats. Two types of contusions were modeled: pneumo-contusion and contusion by a falling load. Methylene blue and indocyanine green were used as photosensitizers. Fluorescence measurements were carried out by imaging and spectrometric methods. A stroboscopic fluorescence imager with an excitation wavelength of 630 nm was used to acquire fluorescence images. The LESA-01-BIOSPEC spectrometer with a He-Ne laser excitation allowed to obtain spectra. It was shown that both methods make it possible to estimate the fluorescence value of methylene blue and indocyanine green in the tissues under study. Moreover, the photographic method also allows to obtain the spatial distribution of fluorescence. The general trend found in the data is a more intense and uniform fluorescence of the dorsal region of rats with methylene blue and a less intense, but more contrasting distribution of indocyanine green. The presented methods are non-invasive, which makes them attractive for diagnostic use. However, due to the shallow depth of signal reception, the condition of the spine can be determined only indirectly, by the condition of the near-surface layers of tissue that accumulate the photosensitizer.
{"title":"Photo and spectral fluorescence analysis of the spinal cord injury area in animal models","authors":"A. M. Udeneev, N. A. Kalyagina, V. F. Reps, V. V. Kozlova, L. A. Pigunova, D. I. Pozdnyakov, A. S. Skobeltsin, V. B. Loschenov","doi":"10.24931/2413-9432-2023-12-3-16-20","DOIUrl":"https://doi.org/10.24931/2413-9432-2023-12-3-16-20","url":null,"abstract":"The purpose of the work is to follow the dynamics of changes in fluorescent signals in the near-surface layers of tissue of injured areas of the back of laboratory animals, which will allow, by indirect evidence, to evaluate the information content of fluorescence diagnosis for subsequent possible diagnostic monitoring of photodynamic therapy of the spinal cord. The model animals were Wistar rats. Two types of contusions were modeled: pneumo-contusion and contusion by a falling load. Methylene blue and indocyanine green were used as photosensitizers. Fluorescence measurements were carried out by imaging and spectrometric methods. A stroboscopic fluorescence imager with an excitation wavelength of 630 nm was used to acquire fluorescence images. The LESA-01-BIOSPEC spectrometer with a He-Ne laser excitation allowed to obtain spectra. It was shown that both methods make it possible to estimate the fluorescence value of methylene blue and indocyanine green in the tissues under study. Moreover, the photographic method also allows to obtain the spatial distribution of fluorescence. The general trend found in the data is a more intense and uniform fluorescence of the dorsal region of rats with methylene blue and a less intense, but more contrasting distribution of indocyanine green. The presented methods are non-invasive, which makes them attractive for diagnostic use. However, due to the shallow depth of signal reception, the condition of the spine can be determined only indirectly, by the condition of the near-surface layers of tissue that accumulate the photosensitizer.","PeriodicalId":37713,"journal":{"name":"Biomedical Photonics","volume":"44 7","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135414381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-23DOI: 10.24931/2413-9432-2023-12-3-11-14
S. B. Smailova, N. A. Shanazarov, T. G. Grishacheva, S. Zh. Salmagambetova, G. S. Aldabergen
Colposcopy allows the examiner to localize potential lesions, assess the severity of the lesion, and obtain a colposcopic guided biopsy. This method has limited sensitivity and specificity, raising serious concerns about the possibility of missing cervical dysplasia. Fluorescent methods for diagnosing precancerous diseases of the cervix and early forms of cancer have an extremely high sensitivity, reaching 90%. The presented results of the study allow us to fully declare the high information content of fluorescent colposcopy in identifying dysplastic lesions on the cervix.
{"title":"Possibilities of fluorescence diagnostics in detecting multicentric focies of cervical dysplasia","authors":"S. B. Smailova, N. A. Shanazarov, T. G. Grishacheva, S. Zh. Salmagambetova, G. S. Aldabergen","doi":"10.24931/2413-9432-2023-12-3-11-14","DOIUrl":"https://doi.org/10.24931/2413-9432-2023-12-3-11-14","url":null,"abstract":"Colposcopy allows the examiner to localize potential lesions, assess the severity of the lesion, and obtain a colposcopic guided biopsy. This method has limited sensitivity and specificity, raising serious concerns about the possibility of missing cervical dysplasia. Fluorescent methods for diagnosing precancerous diseases of the cervix and early forms of cancer have an extremely high sensitivity, reaching 90%. The presented results of the study allow us to fully declare the high information content of fluorescent colposcopy in identifying dysplastic lesions on the cervix.","PeriodicalId":37713,"journal":{"name":"Biomedical Photonics","volume":"23 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135461292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-21DOI: 10.24931/2413-9432-2023-12-2-48-56
E. Filonenko, V. Ivanova-Radkevich
Acne is one of the most common skin conditions in the world. A number of studies have shown that photodynamic therapy (PDT) is safe and effective for both inflammatory and non-inflammatory acne and can significantly improve skin conditions in this disease. The effectiveness of PDT against acne is mainly due to a decrease in the amount of sebum produced by the sebaceous glands due to a decrease in their activity as a result of direct photodynamic damage to the sebaceous glands, eradication of Cutibacterium acnes, and a decrease in the level of hyperkeratosis. Compared with systemic drug therapy, PDT treatment of severe acne has the following advantages: fast results, high efficiency, high selectivity, no systemic adverse reactions and drug resistance, and low recurrence rate. Most often for PDT in patients with acne, drugs based on 5-aminolevulinic acid (5-ALA) and its methyl ester (ME-ALA) are used. At the moment, there are no unified recommendations on PDT regimens for the treatment of this skin pathology. Various studies demonstrate the high efficiency of PDT with a wide range of doses of 5-ALA (3-20%) and ME-ALA (4-16%), light doses (15-120 J/cm2 ), and exposure time (30-90 min). The general trend in studies by different authors is that gentle low-intensity PDT regimens for acne demonstrate the same high efficiency with a significant reduction in pain during irradiation and local skin reactions (erythrema, edema, and hyperpigmentation).
{"title":"Photodynamic therapy of acne","authors":"E. Filonenko, V. Ivanova-Radkevich","doi":"10.24931/2413-9432-2023-12-2-48-56","DOIUrl":"https://doi.org/10.24931/2413-9432-2023-12-2-48-56","url":null,"abstract":"Acne is one of the most common skin conditions in the world. A number of studies have shown that photodynamic therapy (PDT) is safe and effective for both inflammatory and non-inflammatory acne and can significantly improve skin conditions in this disease. The effectiveness of PDT against acne is mainly due to a decrease in the amount of sebum produced by the sebaceous glands due to a decrease in their activity as a result of direct photodynamic damage to the sebaceous glands, eradication of Cutibacterium acnes, and a decrease in the level of hyperkeratosis. Compared with systemic drug therapy, PDT treatment of severe acne has the following advantages: fast results, high efficiency, high selectivity, no systemic adverse reactions and drug resistance, and low recurrence rate. Most often for PDT in patients with acne, drugs based on 5-aminolevulinic acid (5-ALA) and its methyl ester (ME-ALA) are used. At the moment, there are no unified recommendations on PDT regimens for the treatment of this skin pathology. Various studies demonstrate the high efficiency of PDT with a wide range of doses of 5-ALA (3-20%) and ME-ALA (4-16%), light doses (15-120 J/cm2 ), and exposure time (30-90 min). The general trend in studies by different authors is that gentle low-intensity PDT regimens for acne demonstrate the same high efficiency with a significant reduction in pain during irradiation and local skin reactions (erythrema, edema, and hyperpigmentation).","PeriodicalId":37713,"journal":{"name":"Biomedical Photonics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47596858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-21DOI: 10.24931/2413-9432-2023-12-2-16-23
A. Guryleva, A. Machikhin, T. Grishacheva, N. Petrishchev
The proposed approach to microcirculation assessment is non-invasive, informative, and can be implemented during photoactivation, and thus is perspective both for research tasks and clinical practice. The functional principles of the vasculature response to photodynamic exposure, identified using this technique, also foster the efficiency and safety of photodynamic therapy. The developed setup allows simultaneous photodynamic exposure and studying the microcirculation parameters by videocapillaroscopy and photoplethysmography techniques. Photodynamic action is carried out by 662 nm laser radiation with a power density of 15 mW/cm2 in continuous and pulsed modes. The imaging system of the setup consists of a large working distance microscope, an optical filter, and a monochrome camera. The illumination system is based on LED with a central wavelength of 532 nm. The acquired images were processed in order to obtain morphometric and hemodynamic microcirculation data in the inspected skin area. To compare the proposed approach with existing methods, we measured blood flow parameters by a laser Doppler flowmeter. We tested the developed setup on rats injected with a photosensitizer and obtained active vessel maps, photoplethysmograms, and skin vessel density values before, during, and after photoactivation in both generation modes. The proposed approach allows to reveal differences in the microcirculation response to photodynamic effects of low power densities in different modes, in particular, the discrepancy between the time from the start of exposure to the cessation of blood flow and the start of the recovery period.
{"title":"Videocapillaroscopic monitoring of microcirculation in rats during photodynamic therapy","authors":"A. Guryleva, A. Machikhin, T. Grishacheva, N. Petrishchev","doi":"10.24931/2413-9432-2023-12-2-16-23","DOIUrl":"https://doi.org/10.24931/2413-9432-2023-12-2-16-23","url":null,"abstract":"The proposed approach to microcirculation assessment is non-invasive, informative, and can be implemented during photoactivation, and thus is perspective both for research tasks and clinical practice. The functional principles of the vasculature response to photodynamic exposure, identified using this technique, also foster the efficiency and safety of photodynamic therapy. The developed setup allows simultaneous photodynamic exposure and studying the microcirculation parameters by videocapillaroscopy and photoplethysmography techniques. Photodynamic action is carried out by 662 nm laser radiation with a power density of 15 mW/cm2 in continuous and pulsed modes. The imaging system of the setup consists of a large working distance microscope, an optical filter, and a monochrome camera. The illumination system is based on LED with a central wavelength of 532 nm. The acquired images were processed in order to obtain morphometric and hemodynamic microcirculation data in the inspected skin area. To compare the proposed approach with existing methods, we measured blood flow parameters by a laser Doppler flowmeter. We tested the developed setup on rats injected with a photosensitizer and obtained active vessel maps, photoplethysmograms, and skin vessel density values before, during, and after photoactivation in both generation modes. The proposed approach allows to reveal differences in the microcirculation response to photodynamic effects of low power densities in different modes, in particular, the discrepancy between the time from the start of exposure to the cessation of blood flow and the start of the recovery period.","PeriodicalId":37713,"journal":{"name":"Biomedical Photonics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45275682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-21DOI: 10.24931/2413-9432-2023-12-2-11-15
M. Ryabova, L. Mitrofanova, M. Ulupov, V. Stepanova, K. A. Sterkhova
The study presents the results of an experimental study devoted to the choice of the most optimal mode of pulsed contact laser exposure of semiconductor laser with a wavelength of 445 nm in phonosurgery, which implies maximum preservation of anatomically and functionally significant structures of the larynx combined with a radical approach to the pathological process. From the standpoint of the mucoundular theory of voice formation, wave-like oscillations of the vocal folds are possible due to the mobility of the cover layer of the vocal fold (epithelium, superficial layer of the lamina propria) relative to its body (deep layer of the lamina propria, vocal muscle). Thus, any injury at the level of the integumentary layer is associated with the risk of excessive scarring and loss of the ability to wave-like sliding. Pig vocal folds, according to a number of authors, have a structure similar to human ones in terms of both histological structure and acoustic parameters, which justifies the rationality of their use as an experimental model. In a series of experiments using a 445 nm laser, contact pulsed impacts on a biological model were carried out with pulse durations of 10, 20, 50, and 100 ms, followed by evaluation of the following parameters based on the data of histological sections: the depth and width of the ablation crater, the width of the zone of lateral thermal damage. Thus, the most optimal for phonosurgical interventions modes of pulsed laser exposures with a wavelength of 445 nm are described.
{"title":"Pulsed exposure mode of the 445 nm semiconductor laser in phonosurgery: an experimental study","authors":"M. Ryabova, L. Mitrofanova, M. Ulupov, V. Stepanova, K. A. Sterkhova","doi":"10.24931/2413-9432-2023-12-2-11-15","DOIUrl":"https://doi.org/10.24931/2413-9432-2023-12-2-11-15","url":null,"abstract":"The study presents the results of an experimental study devoted to the choice of the most optimal mode of pulsed contact laser exposure of semiconductor laser with a wavelength of 445 nm in phonosurgery, which implies maximum preservation of anatomically and functionally significant structures of the larynx combined with a radical approach to the pathological process. From the standpoint of the mucoundular theory of voice formation, wave-like oscillations of the vocal folds are possible due to the mobility of the cover layer of the vocal fold (epithelium, superficial layer of the lamina propria) relative to its body (deep layer of the lamina propria, vocal muscle). Thus, any injury at the level of the integumentary layer is associated with the risk of excessive scarring and loss of the ability to wave-like sliding. Pig vocal folds, according to a number of authors, have a structure similar to human ones in terms of both histological structure and acoustic parameters, which justifies the rationality of their use as an experimental model. In a series of experiments using a 445 nm laser, contact pulsed impacts on a biological model were carried out with pulse durations of 10, 20, 50, and 100 ms, followed by evaluation of the following parameters based on the data of histological sections: the depth and width of the ablation crater, the width of the zone of lateral thermal damage. Thus, the most optimal for phonosurgical interventions modes of pulsed laser exposures with a wavelength of 445 nm are described.","PeriodicalId":37713,"journal":{"name":"Biomedical Photonics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47211898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-21DOI: 10.24931/2413-9432-2023-12-2-34-47
Д. В. Поминова, Анна Владимировна Рябова, И.Д. Романишкин, И.В. Маркова, Е. В. Ахлюстина, А.С. Скобельцин, Skobeltsin A.S Pominova
A spectroscopic study of the photophysical properties of methylene blue (MB) in aqueous solutions was carried out. Absorption and fluorescence spectra as well as fluorescence lifetime were recorded. The concentration dependence of the intensity and shape of the spectra allowed establishing the ranges of MB concentrations for in vitro and in vivo studies at which aggregation is not observed (up to 0.01 mM, which corresponds to 3.2 mg/kg). Studies of photodegradation in biological media showed that photobleaching of more than 80% in plasma and culture media is observed already at a dose of 5 J/cm2 , while in water at this concentration and dose photobleaching is not yet observed, and at a dose of 50 J/cm2 photobleaching of MB is about 30%. It was found that in media containing proteins and having an alkaline pH, photobleaching occurs significantly faster than in neutral aqueous media. The ionic strength of the solution has no effect on the photobleaching rate. Such photobleaching is caused by the photodegradation of MB rather than the transition to the leucoform.The efficiency of singlet oxygen generation and photodynamic activity were evaluated in vitro. In the investigated range of MB concentrations, the efficiency of singlet oxygen generation is rather low, because positively charged MB binds to negatively charged cell membranes, which leads to a change in the type of photodynamic reaction. The emergence of other reactive oxygen species (ROS), different from singlet oxygen, in cells has been demonstrated. The generation of ROS and the low quantum yield of singlet oxygen generation indicate the tendency of MB to provide the type I photosensitization mechanism (electron transfer with the formation of semi-reduced and semi-oxidized MB+ radicals) rather than to the type II mechanism (energy transfer to oxygen with the formation of singlet oxygen) in biological media and in vivo.
{"title":"Spectroscopic study of methylene blue photophysical properties in biological media","authors":"Д. В. Поминова, Анна Владимировна Рябова, И.Д. Романишкин, И.В. Маркова, Е. В. Ахлюстина, А.С. Скобельцин, Skobeltsin A.S Pominova","doi":"10.24931/2413-9432-2023-12-2-34-47","DOIUrl":"https://doi.org/10.24931/2413-9432-2023-12-2-34-47","url":null,"abstract":"A spectroscopic study of the photophysical properties of methylene blue (MB) in aqueous solutions was carried out. Absorption and fluorescence spectra as well as fluorescence lifetime were recorded. The concentration dependence of the intensity and shape of the spectra allowed establishing the ranges of MB concentrations for in vitro and in vivo studies at which aggregation is not observed (up to 0.01 mM, which corresponds to 3.2 mg/kg). Studies of photodegradation in biological media showed that photobleaching of more than 80% in plasma and culture media is observed already at a dose of 5 J/cm2 , while in water at this concentration and dose photobleaching is not yet observed, and at a dose of 50 J/cm2 photobleaching of MB is about 30%. It was found that in media containing proteins and having an alkaline pH, photobleaching occurs significantly faster than in neutral aqueous media. The ionic strength of the solution has no effect on the photobleaching rate. Such photobleaching is caused by the photodegradation of MB rather than the transition to the leucoform.The efficiency of singlet oxygen generation and photodynamic activity were evaluated in vitro. In the investigated range of MB concentrations, the efficiency of singlet oxygen generation is rather low, because positively charged MB binds to negatively charged cell membranes, which leads to a change in the type of photodynamic reaction. The emergence of other reactive oxygen species (ROS), different from singlet oxygen, in cells has been demonstrated. The generation of ROS and the low quantum yield of singlet oxygen generation indicate the tendency of MB to provide the type I photosensitization mechanism (electron transfer with the formation of semi-reduced and semi-oxidized MB+ radicals) rather than to the type II mechanism (energy transfer to oxygen with the formation of singlet oxygen) in biological media and in vivo.","PeriodicalId":37713,"journal":{"name":"Biomedical Photonics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48991934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-21DOI: 10.24931/2413-9432-2023-12-2-4-10
A. Tseimakh, A. N. Mitshenko, V. Kurtukov, Ia. N. Shoykhet
The article presents the results of a study of survival, markers of hemostasis, proteolysis, and tumor invasion after complex palliative treatment of patients with histologically verified malignant tumors of the bile ducts complicated by obstructive jaundice in two comparable groups of patients. The aim of the study was to evaluate the effectiveness of palliative surgical treatment using photodynamic therapy in patients with malignant tumors of the biliary system complicated by obstructive jaundice. In 10 patients of the main group, palliative surgical treatment was performed using photodynamic therapy; in 20 patients of the comparison group, palliative surgical treatment was performed without photodynamic therapy. In patients of the main group, a statistically significant increase in life expectancy by 104 days (p=0.033) was observed compared to the comparison group. At the same time, a statistically significant effect of tumor necrosis factor α, a marker of tumor invasion, on survival (p = 0.012) and a decrease in its level after photodynamic therapy by 15 pg/ml (p=0.041) was revealed. Thus, palliative treatment using photodynamic therapy of malignant tumors of the bile ducts, complicated by obstructive jaundice, can increase the survival rate of patients by reducing tumor invasion.
{"title":"Palliative surgical treatment using photodynamic therapy for biliary cancer complicated by obstructive jaundice","authors":"A. Tseimakh, A. N. Mitshenko, V. Kurtukov, Ia. N. Shoykhet","doi":"10.24931/2413-9432-2023-12-2-4-10","DOIUrl":"https://doi.org/10.24931/2413-9432-2023-12-2-4-10","url":null,"abstract":"The article presents the results of a study of survival, markers of hemostasis, proteolysis, and tumor invasion after complex palliative treatment of patients with histologically verified malignant tumors of the bile ducts complicated by obstructive jaundice in two comparable groups of patients. The aim of the study was to evaluate the effectiveness of palliative surgical treatment using photodynamic therapy in patients with malignant tumors of the biliary system complicated by obstructive jaundice. In 10 patients of the main group, palliative surgical treatment was performed using photodynamic therapy; in 20 patients of the comparison group, palliative surgical treatment was performed without photodynamic therapy. In patients of the main group, a statistically significant increase in life expectancy by 104 days (p=0.033) was observed compared to the comparison group. At the same time, a statistically significant effect of tumor necrosis factor α, a marker of tumor invasion, on survival (p = 0.012) and a decrease in its level after photodynamic therapy by 15 pg/ml (p=0.041) was revealed. Thus, palliative treatment using photodynamic therapy of malignant tumors of the bile ducts, complicated by obstructive jaundice, can increase the survival rate of patients by reducing tumor invasion.","PeriodicalId":37713,"journal":{"name":"Biomedical Photonics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41560953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-21DOI: 10.24931/2413-9432-2023-12-2-24-33
N. N. Alexandrov, Республика Беларусь, Витебск, аг. Лесной
The authors studied the antitumor efficacy of photodynamic therapy (PDT) in combination with radiodynamic therapy (RDT) in an in vivo experiment. The study was approved by the Ethics Committee of the N.N. Alexandrov National Cancer Center of Belarus (protocol dated February 25, 2022, № 180). The work was performed on 26 white non-linear rats weighing 200 ± 50 g. Pliss lymphosarcoma (PLS) was used as a tumor model, which was transplanted subcutaneously. Photosensitizer (PS) «Photolon» (RUE «Belmedpreparaty», Belarus) was administered intravenously at a dose of 2.5 mg/kg of body weight. The RDT session was performed by the contact method (CRT) once 2.5–3 times after the end of the infusion of the PS on the «microSelectron-HDR V3 Digital apparatus» (Elekta, Sweden) using γ-radiation (192Ir) in a single focal dose 6 Gy. A PDT session was performed once immediately after exposure to ionizing radiation using a «PDT diode laser» (LTD Imaf Axicon, Belarus, λ=660±5 nm) at an exposure dose of 100 J/cm2 with a power density of 0.2 W/cm2 and a power of 0.353 watts. All rats were divided into 4 groups of 6–7 animals each: intact control (IC), PS + PDT, PS + CRT, PS + CRT + PDT. The criteria for evaluating antitumor efficacy were: the average volume of tumors (Vav, cm3 ), the coefficient of absolute growth of tumors (K, in RU), the coefficient of tumor growth inhibition (TGI, %), the frequency of complete tumor regressions (CR, %), the proportion of cured rats (%), an increase in the average duration of dead rats (%). Differences were considered statistically significant at p<0.05. On the 18th day of the experiment, Vav. in groups was 63.25±2.76 cm³; 29.03±6.06 cm³ (p=0.0002); 22.18±5.94 cm³ (р<0.0001); 11.76±3.29 cm³ (p=0.0000), respectively. Coefficients K – 4516.86 RU; 2638.09 RU; 2024.45 RU; 979.00 RU. TGI coefficients – 54.10% (PS + PDT); 64.93% (PS + CRT); 81.41% (PS + CRT + PDT). An increase in the average duration of dead rats indicator – 48.57% (PS + PDT); 60.00% (PS + CRT); 97.71% (PS + CRT + PDT). On the 60th and 90th days of the experiment, the frequency of PR and the proportion of cured rats were the same and amounted to 0%; 16.7%; 14.3%, and 28.6%, respectively. The results obtained indicate the prospects and relevance of further research in this scientific direction.
{"title":"Experimental in vivo studies of the antitumor efficacy of photodynamic and radiodynamic therapy and their combinations","authors":"N. N. Alexandrov, Республика Беларусь, Витебск, аг. Лесной","doi":"10.24931/2413-9432-2023-12-2-24-33","DOIUrl":"https://doi.org/10.24931/2413-9432-2023-12-2-24-33","url":null,"abstract":"The authors studied the antitumor efficacy of photodynamic therapy (PDT) in combination with radiodynamic therapy (RDT) in an in vivo experiment. The study was approved by the Ethics Committee of the N.N. Alexandrov National Cancer Center of Belarus (protocol dated February 25, 2022, № 180). The work was performed on 26 white non-linear rats weighing 200 ± 50 g. Pliss lymphosarcoma (PLS) was used as a tumor model, which was transplanted subcutaneously. Photosensitizer (PS) «Photolon» (RUE «Belmedpreparaty», Belarus) was administered intravenously at a dose of 2.5 mg/kg of body weight. The RDT session was performed by the contact method (CRT) once 2.5–3 times after the end of the infusion of the PS on the «microSelectron-HDR V3 Digital apparatus» (Elekta, Sweden) using γ-radiation (192Ir) in a single focal dose 6 Gy. A PDT session was performed once immediately after exposure to ionizing radiation using a «PDT diode laser» (LTD Imaf Axicon, Belarus, λ=660±5 nm) at an exposure dose of 100 J/cm2 with a power density of 0.2 W/cm2 and a power of 0.353 watts. All rats were divided into 4 groups of 6–7 animals each: intact control (IC), PS + PDT, PS + CRT, PS + CRT + PDT. The criteria for evaluating antitumor efficacy were: the average volume of tumors (Vav, cm3 ), the coefficient of absolute growth of tumors (K, in RU), the coefficient of tumor growth inhibition (TGI, %), the frequency of complete tumor regressions (CR, %), the proportion of cured rats (%), an increase in the average duration of dead rats (%). Differences were considered statistically significant at p<0.05. On the 18th day of the experiment, Vav. in groups was 63.25±2.76 cm³; 29.03±6.06 cm³ (p=0.0002); 22.18±5.94 cm³ (р<0.0001); 11.76±3.29 cm³ (p=0.0000), respectively. Coefficients K – 4516.86 RU; 2638.09 RU; 2024.45 RU; 979.00 RU. TGI coefficients – 54.10% (PS + PDT); 64.93% (PS + CRT); 81.41% (PS + CRT + PDT). An increase in the average duration of dead rats indicator – 48.57% (PS + PDT); 60.00% (PS + CRT); 97.71% (PS + CRT + PDT). On the 60th and 90th days of the experiment, the frequency of PR and the proportion of cured rats were the same and amounted to 0%; 16.7%; 14.3%, and 28.6%, respectively. The results obtained indicate the prospects and relevance of further research in this scientific direction.","PeriodicalId":37713,"journal":{"name":"Biomedical Photonics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42484345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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