Identification of layers in optical coherence tomography of skin: comparative analysis of experimental and Monte Carlo simulated images.

BACKGROUND/PURPOSE: The goal of the study is comparative analysis of the layers in OCT images and the morphological structure of skin with thick and thin epidermis. METHODS: We analyzed the difference between skin with thin and thick epidermis in two ways. The first approach consisted in determination of the thicknesses of layers of skin with thin and thick epidermis of different localizations from experimental OCT images. The second approach was to develop numerical models fitting experimental OCT images based on Monte Carlo simulations revealing structure and optical parameters of layers of skin with thick and thin epidermis. RESULTS: The correspondence between the OCT images of skin with thin and thick epidermis and the morphological structure was confirmed. OCT images of healthy skin comprise three layers in case of skin with thin epidermis and four layers in skin with thick epidermis. The OCT image of the zone of the transition from skin with thick to skin with thin epidermis features five layers. CONCLUSION: The revealed differences in the structure of horny and cellular layers of epidermis, as well as of papillary and reticular dermis in skin with thin and thick epidermis specify different optical properties of these layers in OCT images.

Morphological changes in skin of different phototypes under the action of topical corticosteroid therapy and tacrolimus.

BACKGROUND/PURPOSE: The present study aimed to investigate the influence of topical corticosteroid therapy and tacrolimus on morphological indices of different skin phototypes and to optimize topical therapy using the OCT technique. METHODS: Twenty healthy volunteers aging from 20 to 30 (14 men and 6 women) took part in the study: 10 persons with skin phototype I, II and 10 persons with skin phototype V, VI. Morphological state of the skin was assessed before and during application of topical steroids of different strength and calciumneurin inhibitors for 49 days. Morphological state was studied in vivo using the optical coherence tomograph. RESULTS: Morphological manifestations of skin atrophy with the use of clobetasol propionate appear earlier than with the use of hydrocortisone 17-butyrate; this process was faster in representatives of groups V, VI. Epidermal thinning in the zone of tacrolimus application was not recorded in any phototype. CONCLUSION: Recording of early preclinical signs of epidermis thinning in the course of OCT follow-up may be an indication for changing the corticosteroid therapy by calciumneurin inhibitors, which will permit to individualize the therapy, to increase its efficacy, and to minimize the possibility of complications in each particular case.

Complex assessment of age-specific morphofunctional features of skin of different anatomic localizations.

OBJECTIVE: The goal of the described study was complex assessment of age-specific morphofunctional features of skin of different anatomic localization using optical coherence tomography (OCT). METHODS: Forty-three healthy volunteers aging from 4 to 74 years were enrolled in the study. Optical and functional skin parameters were studied in 18 areas of the human body. All the studied areas were classified as open and closed, depending on external impact. Structural parameters of skin were determined by means of the OCT device equipped with a removable, flexible probe with microscanner (registration certificate no. 022a2035/2213-05) designed and fabricated at the IAP RAS (Nizhny Novgorod, Russia) with longitudinal and transverse resolution of about 20 µm. RESULTS: Age-specific morphofunctional features of skin most evident in areas exposed to external action were found. Statistically significant difference in elasticity (-0.57, P = 0.00012) in areas closed to external action (further referred to as closed areas) and in useful signal depth, hydration and elasticity in areas exposed to external action (further referred to as open areas) was assessed for different age groups. Analysis of the dependence of parameters on age showed statistically significant correlations between age and thickness of cellular layers of the epidermis (-0.33, P = 0.035), pigmentation level (-0.22, P = 0.044) and elasticity in closed areas and highly significant correlations between age and hydration and elasticity in open areas. CONCLUSION: The current work is concerned with investigation of age-specific morpho-functional parameters of skin of different localizations.

[The electrocardiographic changes in patients with malignant neoplasms of the maxillofacial area during radio- and chemotherapy]. / Elektrokardiograficheskie izmeneniia u bol'nykh zlokachestvennymi novoobrazovaniiami cheliustno-litsevoi oblasti pri luchevoi i khimioterapii.

Electrocardiographic signs of changes in the myocardium were detected in 93.2 percent of 74 patients with malignant maxillofacial tumors; this was due to the presence of coronary disease, myocardial dystrophy, essential hypertension, respiratory abnormalities. The development and progress of these shifts much depended on radiotherapy and chemoradiotherapy of the tumors. The most frequent findings were deviations in the end section of the ventricular complex, reflecting the metabolic and ischemic changes in the myocardium, associated with a rise in radiation and polychemotherapy dosage. Extracoronarogenic myocardial lesions and coronary disease progression were clinically characterized by augmentation of cardiac insufficiency and various arrhythmias with mild pain syndrome. These specific clinical and electrocardiographic features of myocardial involvement should be borne in mind when choosing and carrying out radio- and polychemoradiotherapy of patients with maxillofacial tumors.

[Changes in the ECG in the surgical treatment of patients with tumors of the maxillofacial area]. / Izmeneniia EKG pri khirurgicheskom lechenii bol'nykh s opukholiami cheliustno-litsevoi oblasti.

The examination has involved 47 patients operated on for maxillofacial tumors. The patients' ages varied from 16 to 74 yrs. They were divided into 2 groups: Group 1 (n = 24) patients were only surgically treated; Group 2 (n = 23) ones were operated on after a course of radiotherapy; ECGs were recorded routinely. ECG changes, not observed before, were detected in the first days after surgery; these were the changes mainly in the repolarization phase. The most manifest were myocardial injury, ischemia, augmentation of electrolytic and hypoxic disorders, myocardial dystrophy. Arrhythmias and blockages of various types developed. These disorders persisted for up to 1-2 weeks and their time course was positive. In the patients operated on after radiotherapy the ECG changes were augmented by the shifts resultant from radiotherapy effects on the myocardium. These data necessitate ECG monitoring of this patient population after surgery, which helps timely detect and treat acute injuries of the myocardium.