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Cyclins, cyclin-dependent kinases, as well as proteins cooperating with them are responsible for cell cycle regulation which is crucial for normal development, injury repair, and tumorigenesis. D-type cyclins regulate G1 cell cycle progression by enhancing the activities of cyclin-dependent kinases, and their expression is frequently altered in tumors. Disturbances in cyclin expression were also reported in melanocytic skin lesions. The objective of the study was to evaluate the expression of cyclins D1 and D3 in common, dysplastic, and malignant melanocytic skin lesions. Forty-eight melanocytic skin lesions including common nevi (10), dysplastic nevi (24), and melanomas (14) were diagnosed by dermoscopy and excised. Expression of cyclin D1 and D3 was detected by immunohistochemistry and quantified as percentage of immunostained cell nuclei in each sample. In normal skin, expression of cyclins D1 and D3 was not detected. The mean percentage of cyclin D1-positive nuclei was 7.75% for melanoma samples, 5% for dysplastic nevi samples, and 0.34% for common nevi samples. For cyclin D3, the respective values were 17.8, 6.4, and 1.8%. Statistically significant differences in cyclin D1 expression were observed between melanomas and common nevi as well as between dysplastic and common nevi (p = 0.0001), but not between melanomas and dysplastic nevi. Cyclin D3 expression revealed significant differences between all investigated lesion types (p = 0.0000). The mean cyclin D1 and D3 scores of melanomas with Breslow thickness 1 mm were not significantly different. G1/S abnormalities are crucial for the progression of malignant melanoma, and enhanced cyclin D1 and D3 expression leading to increased melanocyte proliferation is observed in both melanoma and dysplastic nevi. In histopathologically ambiguous cases, lower cyclin D3 expression in dysplastic nevi can be a diagnostic marker for that lesion type.

Background: Current data suggest an influence of the hypothalamic-pituitary-adrenal axis on suicidal behavior. The frequency of pituitary adenomas in suicide victims has not yet been investigated. Objectives: The aim of this study was to assess whether the incidence of pituitary adenomas is correlated with suicide. Methods: Serial sections of 151 human pituitary glands obtained upon autopsy were examined microscopically. The glands were collected from 70 suicide victims and 81 subjects whose deaths were classified as unexpected or accidental (nonsuicidal group). The sections were stained with hematoxylin-eosin and the presence of adenoma was confirmed by immunostaining for collagen III. Results: In the suicidal group, pituitary microadenomas were found in 32 cases (47.7%), while in the nonsuicidal group microadenomas were detected in 15 cases (18.3%). The observed difference was statistically significant (p = 0.0003). The relative risk ratio of suicide in persons with pituitary adenomas was estimated at 1.9. Logistic regression analysis in a model controlled for age and sex showed that microadenomas constituted a unique risk factor in this model. The immunohistochemical phenotyping revealed a higher percentage of immunopositive (secreting) microadenomas in the nonsuicidal group as compared to the suicidal group (80.0 vs. 59.38%) and a predominance of growth hormone-secreting microadenomas in both groups. However, these differences as well as differences in the hormonal profiles of microadenomas between the groups were not significant. Conclusions: These results suggest that pituitary adenomas belong to suicide risk factors.

LN-5 monoclonal antibody against human macrophages was found to selectively stain human sebaceous glands in formalin-fixed, paraffin-embedded skin samples. Undifferentiated sebocyte progenitors were negative, and only sebocytes from the onset of their differentiation revealed positive cytoplasmic immunofluorescence. Since there are very few selective and easy-to-use markers of sebaceous glands, LN-5 antibody can offer a simple and relatively specific way to detect human sebocytes from the onset of their differentiation in routinely processed material, both freshly prepared and archival.

Two foci of mature lamellar bone with features of remodeling and with an adjacent hematopoietic compartment were revealed for the first time in an aortic valve homograft by hematoxylin and eosin staining and polarized light microscopy. The valve had been obtained originally from a 52-year-old non-beating-heart donor and implanted as 'fresh antibiotic-preserved' into the left ventricular outflow tract of a 21-year-old man, but was explanted after six years due to valvular insufficiency. The areas close to bone showed the presence of cells resembling osteoblasts, osteoclasts and degenerating chondrocytes. Von Kossa staining disclosed a small area of dystrophic calcification in the vicinity of one bone fragment, whereas the second fragment was accompanied by only weak, diffuse calcification. These findings shows that the formation of ectopic mature bone with secondary development of the hematopoietic compartment can occur in a relatively short time, and suggest that initiators of the process may be present in the grafted valve.