Reactivity of skin microcirculation as a biomarker of cardiovascular events. Pilot study.

BACKGROUND: The role of microcirculatory disorders is progressively being accepted in the pathogenesis of cardiovascular diseases. OBJECTIVE: The purpose of current study is to assess whether we can consider skin microcirculation disorders as a biomarker of cardiovascular events. METHODS: Group 1 consisted of healthy volunteers (n = 31); group 2 (n = 42) consisted of patients with diseases that increase the risk of cardiovascular events; group 3 (n = 39) included patients with the history of cardiovascular events. Skin microcirculation measurement was performed using laser Doppler flowmetry during the heating test. RESULTS: LDF parameters reflecting the rapid response of microcirculation to heating ("Slope 120 s" and "Slope 180 s") significantly differed in three groups (p <  0.05). A decrease in the "Slope 180 s" parameter less than 0.5 PU/s is associated with cardiovascular events (sensitivity 69.2%, specificity 66.7%; the area under the ROC curve, 0.667; 95% confidence interval [CI], 0.545-0.788, p = 0.01). Multivariable logistic regression analysis revealed that "Slope 180 s≤0.5 PU/s" was significantly related to cardiovascular events (adjusted odds ratio = 3.9, p = 0.019, CI 95% 1.2-12). CONCLUSIONS: Reduced reactivity of the skin microcirculation may be useful as a biomarker of severe damage to the cardiovascular system and is promising as a risk factor for cardiovascular events.

[Chronic hypoxia state as one of the factors of increased fluorescence of endogenous porphyrins in alive biological tissues].

The hypothesis about the influence of chronic hypoxia in soft alive tissues on the intensity of He-Ne laser-induced fluorescence of endogenous porphyrins in tissues in the red region of the optical spectrum is discussed. Some theoretical prerequisites for enormous accumulation of porphyrins in soft tissues in a number of pathological cases and diseases are presented. A method for conducting clinical experimental trials to verify the hypothesis with the use of up-to-date laser noninvasive fluorescent diagnostics is proposed. Both the theoretical reasoning and new clinical experimental data show that chronic hypoxia can be one of the factors responsible for the appearance of a strong and abnormal laser-induced fluorescent signal from biotissues in the spectrum range 600-800 nm, which is associated with abnormally high accumulation of endogenous porphyrins in tissues.

[A specific feature of the procedure for determination of optical properties of turbid biological tissues and media in calculation tasks of medical noninvasive spectrophotometry].

The goal of this work is to discuss the problems of accuracy and reliability of the procedure for determination of optical per-unit-length properties of light-scattering biological tissues and media in medical noninvasive spectrophotometry. The determination procedure is based on the two-flux Kubelka-Munk approach. A simple one-dimensional model problem is formulated. The accurate solution of this problem is compared to its solution based on the Kubelka-Munk approach in various approximations. It is shown that in the general case of light-scattering and absorbing medium use of two independent transport coefficients (for scattering and absorption processes), as suggested in the conventional Kubelka-Munk approach, leads to errors of direct calculation of properties of backscattered and transmitted radiation in biological tissues. More valid and accurate expressions for transport coefficients can be obtained on the basis of a particular solution of the problem for a surface element of the model medium with known photometrical properties. This method makes it possible to determine accurately the radiation flux at the external boundary of the medium using the Kubelka-Munk approach. It is expected that solution of the inverse problem would make it possible to reconstruct accurately the optical properties of biological tissues from the experimental data.

[Value of new laser technologies in occupational diseases diagnostics].

The article deals with results of microhemodynamics assessment through new methods of noninvasive laser diagnostics--doppler flowmetry and spectrophotometry ("Spectrotest" device)--in vibration disease patients to verify origin of angiodystonic and angiospastic syndromes. The methods enable to define type of microcirculatory disorder, to evaluate quantity of revealed changes, to assess blood content of superficial tissues in fingers, blood oxygenation. Spastic type of microcirculation is indicative to include ACF inhibitors into treatment complex.

[Biospectroscopy-based endoscopy with low-intensive laser radiation for differential diagnostics and treatment of peptic ulcer].

The article covers results of application of biospectrometry-based endoscopy with low-intensive He-Ne laser radiation in complex therapy of torpid esophageal, gastric, and duodenal ulcers. The authors are the first to offer a method based upon individual biophotometric control (autofluorescence, oxigination), which allows verification of the ulcerous process character, individual optimization of treatment and objective control of ulcer regression.

[Increasing the effectiveness of skin cancer T(2-3) N0M0 radiotherapy by use of radiosencibilizers].

The paper presents an attempt to increase the effectiveness of radiotherapy of locally advanced skin cancer by use of radiomodifiers. With this aim the researchers used metronidozol (MZ) and low-intensive laser emission (LILE), whoes radiosensibilizing activity is based on overcoming radioresistance of tumor hypoxic cell fraction. In order to increase MZ concentration in the tumor and eleminate its toxic effect the authors developed a new radiosensibilization technique, implying local use of a drug applicator. The technique is based on use of textile materials with specifed medical qualities (the method of their production was developed by the Scientific and Practical Association "Textileprogress"). The second direction of the research consisted in use of low-intensive laser emission as a radiosensibilizer, which was considered to be possible due to theoretical and experimental data suggesting the LILE capability of activating microcirculation in tumor and surrounding tissues. According to the authors of the article, the improvement of tumor microsirculation must increase tumor cell oxygenation, thus increasing their radiosensitivity. Applying radiosensibilization of hypoxic cells with MZ and LILE in radiotherapy of T2 basal cell and squamous cell carcinomas with the tumor size 4-5 cm and T3 tumors using original dose fractioning regimens (TFD 72 to 73 Gy) allows significant improvement of immediate treatment results without increase in local radioreactions and without substantial influence of the recurrence rate.

[Significance of laser dopplerometry in diagnostics of upper extremity occupational angiopathy].

The paper demonstrates the results of the application of laser dopplerometry supplemented with respiratory, thermal and occlusive functional tests, as a new non-invasive method of microcirculation evaluation. Initially the majority of patients have spastic or hyperemic microcirculation disturbances in the skin of the fingers. Functional tests allow specification of the mechanisms of these disturbances, such as microhemodynamic inertness and the suppression of slow circulatory rhythms, which demonstrate the presence of myogenic tonus disorder and prove that vibration has direct influence on vascular wall cells. The manifestation of neurogenic component is the dominance of sympatic vasomotor reflex. The paper also demonstrates the dominance of vasoconstrictor effect over vasodilatatory one.

[Low contrast non-color vision in patients with multiple sclerosis]. / Nizkokontrastnoe cherno-beloe zrenie u bol'nykh rasseiannym sklerozom.

OBJECTIVE: Vision impairment is one of the most typical characteristics of multiple sclerosis (MS). This pathology develops due to the lesions of optic nerves and optic tracts in the brain or eye movement dysfunction. Low contrast vision impairment is very frequent and early detected. We assessed low contrast non-color vision in patients with MS. MATERIAL AND METHODS: We examined 56 MS patients and 33 healthy controls. Computed optometric testing was used (grey-colored digits of the standard size were shown against the background of the different shade of grey on the computer monitor). RESULTS AND CONCLUSION: The results demonstrated low-contrast vision dysfunction while high-contrast vision remained intact. The level of low-contrast vision in MS patients differed significantly from that in the controls. The higher severity of visual disturbances was identified during high illumination. The direct correlation between the degree of low-contrast vision dysfunction and the level of disability on EDSS was found.

Laser clinical diagnostics as a promising trend of biomedical radio electronics.

This article outlines the up-to-date achievements of laser noninvasive clinical diagnostics. The outlook for its development and its close connection with the problems of physics, mathematics, and the electronic instrument-making industry are shown. The combined application of these disciplines in biology and medicine creates a novel integrated trend--medical physics.

[Registration of surface fluorescence of endogenous porphyrins during low-level laser therapy of gastric and duodenal ulcers]. / Izmerenie poverkhnostei fluorestsentsii éndogennykh porfirinov v protsesse lazeroterapii iazv zheludka i dvenadtsetiperstnoi kishki.

With the use of the developed opto-fiber spectroscope and gastroscope, the intensity of fluorescence from the ulcer surface into the gastrointestinal tract was measured in the range of 670-690 nm under the He-Ne laser (= 632.8 nm) illumination. Surface fluorescence data were collected with the use of a special diagnostic fiber with a total diameter of about 2 mm, which combines some illuminating and receiving fibers. To do the measurements, the diagnostic fiber was brought into a slight contact with the mucosa surface. The quantitative results were calculated with the use of the special fluorescent contrast coefficient (Kf), which takes into account the backscattered light as well. After the fluorescent diagnostic procedure, the low-level laser therapy was applied to all patients. It was found that: first of all, during the laser medical cure the registered fluorescence for the patients with a good dynamics of treatment had an evident tendency to a decrease, and the coefficient Kf for observed ulcers tended to approach the value obtained from normal mucosa (Kf), which indicates the normalization of the porphyrin content in the tissue. Second, the retrospective analysis of the efficacy of laser therapy versus initial values of Kf showed that, for the patients with the initial values Kf = 0.2, the efficiency of the laser treatment was the highest: the relation between the patients with good treatment results and bad ones was 4:1 (more than 80%). For the initial Kf = 0.2-0.3, this relation was 3:1 but for Kf = 0.4-0.5 it was 2:3. The differences in the efficiency of the low-level laser therapy, except the cases of the cancer in the ulcers, may be due to different content of porphyrin in the tissue: at high concentrations of the photosensitizer in the ulcer, the effect of the overdosing could be realized. In this case, another technology of laser illumination is needed. The results are discussed in terms of the free-radical conception of the stimulating effect of laser radiation.

[Basic principles of system software maintenance for multi-functional non-invasive spectrophotometric diagnostic devices and complexes]. / Bazovye printsipy organizatsii sistemnogo programmnogo obespecheniia mnogofunktsional'nykh neinvazivnykh spektrofotometricheskikh diagnosticheskikh priborov i kompleksov.

Due to the promotion of methods and devices of non-invasive spectrophotometric diagnostics in the sphere of medicine, software support for such diagnostic systems has been growing to be a topical issue. The general ideology of designing the system software support for multi-function spectrophotometric diagnostic tools is under discussion in the paper. The need in a multi-stratum structure of presenting, analyzing and processing the diagnostic findings, i.e. beginning from physical result interpretation to its common medical interpretation, is substantiated.

[Prospects for promoting noninvasive spectrophotometry diagnosis in medicine]. / Perspektivy razvitiia neinvazivnoi spektrofotometricheskoi diagnostiki v meditsine.

Different aspects of optic invasion-free diagnostics in medicine are under discussion. The diagnostic possibilities of the method as well as the principles of its equipment-related and methodological realization are briefly analyzed. A conclusion is made on a unified optic invasion-free diagnostic technology in medicine and on its similarity to the general methods of laboratory spectrophotometry. Therefore, the designing of universal diagnostic complexes combining various diagnostic techniques on the bases of common diagnostic equipments is the most promising trend in developing the appropriate outfit for the diagnostic sphere.

[Clinical morphological aspects of chronic gastroduodenitis in patients with vibration disease]. / Kliniko-morfologicheskaia kharakteristika khronicheskogo gastroduodenita u bol'nykh vibratsionnoi bolezn'iu.

The article covers data of endoscopy, histologic and bacteriologic study of gastric lavage in 55 vibration disease patients (random select). Duodenal peptic ulcer was found in 1 patient, gastric polyp--in 1 patient, erosive gastroduodenitis in 14 (25.45%) patients, chronic gastroduodenitis without destruction of mucosa--in 39 (70.91%) patients. Contamination with Helicobacter pylori appeared in 97% of cases, being significant and subject to therapy only in 35.29% of patients.