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Biomedical Photonics

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Vol 7, No 3 (2018)
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https://doi.org/10.24931/2413-9432-2018-7-3

ORIGINAL ARTICLES

4-20 1309
Abstract

Early diagnosis of caries and tooth enamel microcracks is of great importance for preventing the destruction of healthy tooth enamel. In

order to detect microcracks in the enamel and pathogenic microflora foci that can cause caries, nanoform of aluminum phthalocyanine (AlPc) can be used as a marker. In a colloidal solution, the nanoparticles do not fluoresce, unlike their molecular form. To convert the particle into its molecular form, it is necessary to have a solvent or specific environment (bacteria, macrophages, etc.). That is why the hydrophobic nanoparticles of aluminum phthalocyanine (nAlPc) can act as markers for detecting hidden pathogenic microflora during fluorescent diagnostics. Further reduction of the diagnosis time and increase the efficiency can be achieved by using biologically compatible surfactants as additional activators of nAlPc.

In order to carry out local fluorescence spectroscopy of enamel microcracks and pathogenic microflora foci on the enamel surface, a model compound containing surfactants, auxiliary components and nAlPc colloid at a concentration of 10 mg/l was prepared.

Studies on the interaction of the model compound with nAlPc and Protelan MST-35 with tooth enamel ex vivo have shown this surfactant to be a promising auxiliary activator of the nanoparticles, allowing conducting local fluorescence spectroscopy of the tooth enamel surface 3 min after application. In addition, statistical processing of the results showed the effectiveness of using the model compound for local fluorescence spectroscopy of the enamel surface in order to detect the enamel microcracks and the pathogenic microflora accumulation foci that can lead to the development of a cariogenic process.

21-28 1099
Abstract

This work presents the results of performing intraoperative photodynamic therapy (IOPDT) on 22 patients with recurrent pelvic tumors

(cervical cancer – in 18 patients, cancer of the corpus uteri – in 3 patients, cancer of the anal canal – in 1 patient). Prior to the PDT procedure, the patients were injected with photolon photosensitizer (PS) at a dose of 1.0–1.1 mg/kg. After the injection of PS, local fluorescence spectroscopy of tumor lesions was performed to determine the accumulation of drug in various areas of tumors and healthy tissue. Intraoperative laser irradiation was carried out 3–5 hours after the photolon injection with light at 662 nm wavelength using "Latus-2" laser device with a power density of 140 mW/cm2 and the density of light energy of 40–60 J/cm2, the number of irradiation fields was 3–5 depending on the anatomical features.

The follow-up period after surgical treatment combined with PDT was from 6 to 24 months. Analyzing the immediate results of the treatment, there were no undesirable events or increase in the number of postoperative complications compared to patients treated without IOPDT. Were registered: transient increase in ALT and AST levels – in 5 patients (13.6%), reduction of oxygenation during anesthesia – in 20 (90.9%), transient fevers in the postoperative period – in 7 (31.8%).

It was noted that IOPDT with photolon drug, while slightly extending the time of the operation, is well tolerated by patients and does not lead to an increase in the number of early postoperative complications or the length of hospitalization.

29-35 972
Abstract

Currently, reconstructive-plastic surgery is becoming the standard for surgical and combined treatment of breast cancer (BC) patients.

With a one-stage reconstruction of the breast, the use of biological implants that can replace muscle autografts and, consequently, reduce trauma, blood loss and operation time, and also to avoid defects in the donor zones is becoming topical. From 2014 to 2017, 151 reconstructive operations on 121 patients with BC (average age 41.5 years) using synthetic and biological materials were carried out in P.Herzen Moscow Oncology Research Institute. 0 stage of BC TisN0M0 was diagnosed in 11 (9.1%) patients, I stage – in 52 (42.9%), IIA – in 41 (33.9%), IIB – in 9 (7.4%), IIIA – in 4 (3.3%), IIIB – in 2 (1.7%), IIIC – in 2 (1.7%). To strengthen the lower slope, a biological implant – Permacol acellular dermal matrix, was used in 34 cases. Cosmetic result was rated as excellent in 20 (58.9%) cases, good in 11 (32.3%), unsatisfactory in 3 (8,8%). Biological materials are an important addition to various options for breast reconstruction. The criterion for selecting the material for strengthening the lower slope of the breast with subcutaneous or cutaneous mastectomy for cancer with a one-stage reconstruction using a silicone endoprosthesis is the pinch-test value.

36-42 1017
Abstract

Malaria causes a serious health problem in the tropical and subtropical regions of the globe. In many cases, the consequences of this disease are fatal. Therefore, a simple, fast, accurate and affordable diagnostic system for the early detection of this disease is necessary for the timely administration of antimalarial drugs.

The malarial parasite, during its intra-erythrocyte development, processes a significant amount of hemoglobin, which in this case turns into a hem form called hemozoin. Hemozoin and hemoglobin have different molar extinction coefficients at certain optical wavelengths, hence, light absorption and an optoacoustic signal (OAS) from the infected cell will be different from that of a healthy cell. The paper describes the developed theoretical model intended for studying the influence of intra-erythrocyte malarial parasite development on optoacoustic signals. The OAS were calculated based on the models of healthy and infected blood modeled on the basis of a 3D model.

The simulated OAS were analyzed in the temporal and frequency domains to obtain signs of infection at various stages. The calculated OAS spectra have different amplitude levels, which indicates that the optoacoustic method can be useful for differentiating various intraerythrocyte stages of the malarial parasite. The carried out modeling and the results obtained allow us to continue working on the creation of an optoacoustic flow cytometer.

43-46 1308
Abstract

A comparative experimental study of the specific activity of drugs based on 5-aminolevulinic acid (5-ALA) and its hexyl ester (5-ALA HE) was carried out. Their ability to induce the synthesis of photoactive protoporphyrin IX in the healthy tissues of the rabbit bladder when instilling the drug solutions at various concentrations has been estimated. It was shown that 5-ALA HE results in the induction and accumulation of PPIX in the rabbit bladder epithelium at much lower concentrations than 5-ALA. Thus, a significant increase in the fluorescence intensity in comparison with the control was achieved by instillation of 5-ALA HE solution in the rabbit’ bladder at a concentration of only 0.0001% (fluorescence intensity 2.20±0.60 a.u.), and for 5-ALA – only when using a solution at a concentration of 0.3% (fluorescence intensity 2.60±1.02 a.u.).

LITERATURE REVIEWS

47-56 2400
Abstract

Selective laser trabeculoplasty (SLT) is the “golden standard” of laser glaucoma surgery. Its efficacy can be compared to pharmacological therapy, while in some cases its advantages may even lead to a more stable hypotensive effect. SLT may be used as a primary treatment for primary open-angle glaucoma patients and patients with ocular hypertension, while also considered safe and effective in cases when a repeat procedure is required. SLT may potentially decrease the demand for antiglaucoma drugs, improve patient’s response to treatment, make the treatment more comfortable and overall increase the patient’s quality of life. New modifications of standard laser treatment procedures have been emerging lately. This article summarizes scientific data on the efficacy and safety of the new generation of laser trabeculoplasty. It specifies the charateristics of micropulse laser trabeculoplasty (MLT), pattern-scanning trabeculoplasty (PLT) and titaniumsapphire laser trabeculoplasty (TSLT) and recounts the latest research dedicated to them.



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ISSN 2413-9432 (Print)