[Histological verification of autofluorescence borders of periorbital skin tumors]. / Gistologicheskaya verifikatsiya autofluorestsentnykh granits novoobrazovanii kozhi periorbital'noi oblasti.

Tumor borders are one of the most significant characteristics of any tumor, including that of the skin. PURPOSE: To compare histological borders of periorbital skin tumors with their autofluorescence borders built from the analysis of non-induced protoporphyrin IX autofluorescence. MATERIAL AND METHODS: The study group included 8 patients with skin tumors of the eyelids, periorbital region, eyebrow and zygomatic regions aged 54-88 years. The tumors varied in size from 2 to 8 mm and all displayed signs of basal cell carcinoma (BCC). At admission, all the patients underwent non-induced autofluorescence diagnosis. The images were processed with the «CancerPlot¼ program. During radio excision, the autofluorescent border of each neoplasm was marked with a surgical incision of about 5 mm long and 2 mm deep. RESULTS: Upon pathomorphological examination, solid BCC was identified in 7 cases. The remaining case was senile keratosis. All reference incisions were located in healthy tissues not farther than 1 mm from the tumor (or keratosis locus, correspondingly). CONCLUSION: By the example of facial BCC, an evident correlation was established between histological borders of the tumor and its native (non-induced) protoporphyrin IX autofluorescence.

[Abnormal distribution of trace elements in keratoconic corneas]. / Pereraspredelenie mineral'nykh elementov v rogovitse pri keratokonuse.

UNLABELLED: Our understanding of etiology and pathogenesis of many disorders, corneal included, greatly relies on existing knowledge in human biochemistry and biophysics. This study was aimed at chemical mapping of normal and keratoconic corneas. MATERIAL AND METHODS: Modern methods of analytical chemistry, such as X-ray fluorescence and energy-dispersive X-ray spectroscopy on the basis of scanning electron microscopy, were adapted to the needs of cornea research. Normal human corneas obtained postmortem and corneal buttons obtained during penetrating keratoplasty were analyzed. RESULTS: In keratoconus, abnormal accumulation of iron, copper, and zinc was found in the periphery of the buttons, i.e. in the zone of visible pigmentation (Fleischer ring), while the center - the ectatic zone - demonstrated a total deficiency of trace elements. This data suggests that keratoconus pathogenesis is associated with impaired mineral metabolism and formation of a physicochemical barrier in corneal tissues with subsequent keratectasia. The authors discuss several possible vicious circles involved.