Laser-induced fluorescent visualization and photodynamic therapy in surgical treatment of glial brain tumors.

High-grade gliomas have a diffuse and infiltrative nature of the growth of tumor cells, due to which the achievement of radical resection is difficult. Surgical resection completeness of brain tumors is an important factor in prolonging the life of patients. An accurate definition of tumor boundaries and residual fluorescent regions is impossible due to imperfections of the equipment used for fluorescent imaging. 5-aminolevulinic acid (5-ALA) is a precursor of protoporphyrin IX (PpIX) in humans and is clinically used to detect and treat tumors. Currently, fluorescence-guided surgery with PpIX used a surgical microscope with an excitation wavelength in the blue spectrum range. Because of its low ability to penetrate into biological tissue, blue light is ineffective for providing high-quality fluorescent navigation. Also, when performing an operation using radiation in the blue spectrum range, the photosensitizer's surface layer (PS) often bleaches out, which leads to frequent errors. The use of red light emission makes it possible to slow down the PS bleaches out due to the absorption properties of PpIX, but this task is technically more complicated and requires highly sensitive cameras and specialized optical filters. The new two-channel video system for fluorescent navigation has a radiation source in the red range of the spectrum, the penetration depth of which is greater than the blue light, which makes it possible to increase the depth of probing into biological tissues. The study's clinical part involved 5 patients with high grade glioma and 1 patient with low grade glioma: grade III oligodendrogliomas (2), grade IV glioblastomas (3), and grade II diffusion astrocytoma (1).

[The use of the method of photodynamic therapy for the treatment of the patients presenting with primary and recurrent laryngeal cancer]. / Primenenie metoda fotodinamicheskoĭ terapii dlia lecheniia bol'nykh s pervichnym i retsidivnym rakom gortani.

The objective of the present study was to evaluate the effectiveness of the method of photodynamic therapy (PDT) for the treatment of the patients presenting with primary and recurrent laryngeal cancer. A total of 20 patients at the age from 46 to 82 (mean 61.3±7.5) years suffering from laryngeal cancer (17 men and 3 women) were available for the observation. PDT was based on the use of «Atkus¼ lasers (Russia) operated at a wavelength of 662 nm and a power up to 3 W as well as «Lagus¼ lasers(wavelength: 662 nm, power: up to 3 W). It was shown that the effective treatment of laryngeal cancer by PDT is possible under condition of the thorough selection of the patients with a definite growth type and localization of the tumour. Complete resorption (CR) was achieved in 100% of the patients with the early (I-II) stages of laryngeal cancer and in 90% of those having exophyticneoplasms less than 1 cm in size. Moreover, the beneficial effect of PDT was documented in the treatment of limited relapses of laryngeal cancer in tracheostoma following combined therapy. It is concluded that the proposed method can be recommended for the palliative care in order to reach homeostasis in the patients with extended bleeding tumours and also for the reduction of their volume andrecanalization of the trachea to improve the patients' quality of life. The authors maintain that PDT can be in many cases performed under the outpatient conditions.

[Current trends in photodynamic therapy of neoplasms and non-neoplastic diseases]. / Sovremennoe sostoianie problemy fotodinamicheskoi terapuu raka i neopukholevykh zabolevanii.

The photodynamic therapy of tumors is a modern therapeutic modality for organ-preserving treatment of oncological diseases. The method is based on selective laser irradiation of tumor tissues previously sensitized by tumorotropic dyes. During the last decades, photodynamic therapy has become worldwide known as a proper approach to the treatment of the patients with malignant tumors of various locations and a number of nontumoral diseases. The characteristics of modern photosensitizers and light sources for photodynamic therapy and their clinical applications are reviewed.

[The photodynamic inactivation of Candida guilliermondii in the presence of photodithazine]. / Fotodinamicheskaia inaktivatsiia drozhzhei Candida guilliermondii v prisutstvii fotoditazina.

Photodithazine, a glucosamine salt of chlorin e6, enhanced the inactivation of Candida guilliermondii cells by visible light. The sensitizing effect of photodithazine was found to be related to free or cell surface-bound molecules of this dye. Sodium azide (a singlet oxygen quencher) and propyl gallate (an inhibitor of lipid peroxidation) protected yeast cells from the photodithazine-enhanced photoinactivation.

[Photoquenching of the bioluminescence of the genetically engineered Escherichia coli TG1 (pXen7) strain in the presence of photodithazine]. / Fotoindutsirovannoe podavlenie bioliuminestsentsii genno-inzhenernogo shtamma bakterii Escherichia coli TG1 (pXen7) v prisutstvii fotoditazina.

The photoquenching of the bioluminescence of the genetically engineered Escherichia coli TG1 (pXen7) strain was studied in the presence of the photosensitizer photodithazine, a glucosamine salt of chlorin e6. The photosensitized quenching of the bioluminescence was found to correlate with the colony-forming ability of the strain. The data obtained are discussed from the standpoint of using biosensor luminescent bacterial systems for the assessment of the efficiency of photosensitizers in antimicrobial photochemotherapy.

[Experimental study of photodynamic effect on bacterial wound microflora]. / Fotodinamicheskoe vozdeistvie na bakterial'nuiu mikrofloru v éksperimente.

The in vitro study of the influence of photodynamic action (with the use of photosensitizer "Photosens", laser and non-laser irradiation) on the strains of the main representatives purulent wound microflora was carried out. Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis cultures have been isolated from wound secretions and identified. The photosensitizer was shown to produce no bactericidal effect by itself. Irradiation with laser and non-laser light sources induced a sharp decrease in the number of viable cells in the cultures under study. The irradiation of the photosensitizer led to its activation, manifested in bactericidal action. The results thus obtained confirm good prospect of using photodynamic therapy for the treatment of purulent wounds.

[Photodynamic therapy of recurrent and residual oropharyngeal and laryngeal tumors]. / Fotodinamicheskaia terapiia tetsidivnykh i "ostatochnykh" opukholei orofaringolaringeal'noi oblasti.

Photodynamic therapy (PDT) was given to 61 patients with recurrent cancer of the tongue, oral mucosa, lower lip, oro- and nasopharynx, larynx. Photosensitizers photogem and photosens of Russian produce were employed. The radiation was given twice with the interval 24 and 48 hours, the exposure to light 3 to 30 min. The impact was external, through the instrumental canal of the fibroscope, by intracavitary and interstitial techniques. The response was assessed within 4-6 weeks after the PDT course. The effect was observed in 95.1% patients. Its duration ranged from 4 months to 5 years. Complete resorption of the tumor was achieved in 57.4%. The treatment failed in 4.9% patients.

[Clinical features, diagnosis and treatment for trophic, late radiation ulcers and ulcers undergone malignant transformation]. / Klinika, diagnostika i lechenie ozlokachestvlennykh, troficheskikh i pozdnikh luchevykh iazv.

Clinical and histological examinations of 1562 patients with trophic and advanced radiation ulcers were carried out during 30 years. Malignant transformation of the ulcers has been revealed in 14 of them: sarcoma--in 1, and cancer--in 13. From all the patients with advanced radiation ulcers, malignant transformation was detected in 7.07%, and in cases of ulcers of the other genesis--in 0.81% of cases. Malignant transformation of ulcers of non-radiation genesis occurs on the average after 19 years, and of radiation one--after 3.8 years. Early diagnosis of skin cancer, at the site of the ulceris rather difficult and depends thoroughly on oncological alert and timely morphological examination of various skin areas. A new, rather perspective and relatively simple method of treatment for ulcerative forms of cancer of the skin is photodynamic therapy (PhDT). This method showed to be effective even in those patients who failed conventional methods of treatment (relapses), or had contraindications. PhDT has broaden the armory of the oncologists and oncodermatologists for treatment of complicated forms of cancer of the skin.

Hematoporphyrin derivative or phthalocyanine photosensitized hemolysis of erythrocytes under laser irradiation.

The effect of laser irradiation on the photosensitized hemolysis of rabbit erythrocytes was investigated. Two photosensitizers of domestic production were used: Photohem (a hematoporphyrin derivative) and Photosense (sulfonated phthalocyanine aluminium). The hemolysis was activated by laser irradiation in the presence of Photohem or Photosense. The process depended on the irradiation dose, the concentration of the photosensitizers and on the time during which the erythrocytes were incubated with the photosensitizers. Three lasers with wavelengths 520, 632.8 and 850 nm were used. The photosensitized hemolysis of rabbit erythrocytes was found to be inhibited by antioxidants.

[Paradigm of radiation-laser medical equipment and technology]. / Paradigma radiatsionno-lazernoi meditsinskoi tekhniki i tekhnologii.

Based on quantum chemistry and chemical kinetics, the paper formulates basically new concepts of the possibility of controlling biochemical reactions in biological tissues by simultaneously making abnormal human visceral foci, in cancer diseases in particular, exposed to two rays via radiation and optic laser radiations. The paper also presents experimental findings of the channeling of X-ray and fluxes of charged particles along the fiber wave guides. It considers the circuit engineering of a medical endoscopic device that concurrently transmits optic laser radiation and fluxes of penetrating radiation into the viscera.

[Photodynamic therapy and fluorescent diagnosis of malignant tumors using preparation photogem]. / Fotodinamicheskaia terapiia i fliuorestsentnaia diagnostika zlokachestvennykh opukholei preparatom fotogem.

From February, 1992 to May, 1993 photodynamic therapy (PDT) was applied at the State Scientific Center of Laser Medicine and the Moscow Scientific-Research Oncological Institute for the treatment of 60 patients with primary and metastatic malignant tumors of the breast, skin, respiratory and digestive organs, female reproductive organs, and urinary bladder. Forty-eight patients underwent one course of PDT, 11 patients received 2 courses, and one patient was given 3 courses. Russian-produced Photogem was used as the photosensitizer. It was infused intravenously 24, 48, or 72 hours before exposure to laser beam. The dose of Photogem ranged from 2.5 to 6.0 mg/kg. The density of laser radiation power during PDT sessions ranged from 100 to 1,600 mVt/cm2, energy exposure from 80 to 600 J/cm2, duration of irradiation from 3 to 45 minutes. After treatment the patients were studied in follow-up periods of 4 weeks to 17 months. Complete regression of the tumor verified morphologically was found in 62%, partial regression in 34%, and limited response or absence of an effect in 4% of cases. Fluorescent-diagnostic examination of patients was conducted at the Moscow Scientific-Research Oncological Institute. It demonstrated the reliability of this diagnostic method with the use of the preparation Photogem as the photosensitizer.

[Active screening for cancer patients]. / Ob aktivnom vyiavlenii onkologischeskikh bol'nykh.

Basic conventional methods of secondary cancer prevention are clinically reviewed. The authors hold that further extensive development of present-day organisational patterns (wider screening coverage of population, growing number of objective diagnostic techniques) shows no promise in inducing positive trends of cancer outcome statistics. Scientifically validated diminution of precancer definition is stated. Selection of population at risk for cancer and proper examination of these risk groups seem most perspective in improvement of cancer statistics.

[Lung cancer in women in Moscow (epidemiology, etiology and surgical treatment)]. / Rak legkogo u zhenshchin v Moskve (nekotorye voprosy épidemiologii, étiologii i khirurgicheskogo lecheniia).

In the studied period (1973-1987) the lung carcinoma morbidity rate among females of Moscow, in general intensive indices (per 100,000 females), showed a tendency to reduce (18.4 in 1973 and 15.1 in 1987). A reverse tendency is mostly encountered in other countries. More than half of patients with lung carcinoma were over 70 years of age. The ratio of males with lung carcinoma to that of females grew from 3.0:1.0 in 1973-1977 to 3.6:1.0 in 1983-1987. In the period from 1979 to 1988, 380 females suffering from carcinoma of the lung were hospitalized to the thoracic department of the clinic. Operations were performed on 215 of them, 174 of the operations were radical. The ratio of operated on males to females was 7.4:1.0. The frequency of central carcinoma among females was 28.8%, which was half that among males (56%). The number of operations according to volume was as follows: pulmonectomy 37, lob- and bilobectomy 119, wedge resection 18. More than half of the female patients had the glandular form of lung carcinoma and its incidence was 3-5 times that among males who were operated on (10-15%). According to the authors, the principal etiological factors are smoking, a history of another malignant tumor, and the exogenous effect of the consequences of urbanization.