Effect of prolactin-induced protein on human skin: new insight into the digestive action of this aspartic peptidase on the stratum corneum and its induction of keratinocyte proliferation.

Human prolactin-induced protein (PIP) is a major protein found in exocrine fluids such as saliva and sweat. Intriguingly, PIP possesses residues (human PIP (hPIP): PIP (29-63)) that display similarity to the aspartic peptidase candidapepsin. Here, we aimed to determine the effect of PIP as a protease on normal skin structure. Using an adhesive tape-stripping technique, we applied hPIP peptide on the corneocytes of normal-appearing facial skin from infants with eczema and healthy infants and then analyzed the morphological structure of corneocytes with Nile Red fluorescence. We also repeatedly applied the hPIP peptide onto the surface of a three-dimensional (3-D) human skin model and then analyzed any changes to the stratum corneum and epidermis using light microscopy and scanning electron microscopy. In both infant groups, a decrease in hydrophobic lipids from the cornified envelope was observed after treatment with hPIP. The peptide hPIP appeared to digest the fine structure of the stratum corneum and induce a proliferation of epidermal keratinocytes within the 3-D human skin model. Our results suggest that aspartic peptidase of PIP found in sweat or saliva deteriorates the skin barrier in a de novo manner, which potentially leads directly to the proliferation of epidermal keratinocytes without any external antigenic factors.

Ascitic fluid due to type II herpes simplex virus infection: report of a case with immunocytochemical confirmation.

Herpes simplex virus (HSV) infection is usually observed in the oral cavity and external genitals, and HSV peritonitis is extremely rare. Herein, we report a case of type II HSV peritonitis successfully diagnosed by ascitic cytology. A 66-year-old Japanese man, who had been treated with steroid inhalation for 5 years due to chronic obstructive pulmonary disease, was suspected to have acute cholecystitis. Laparoscopic cholecystectomy and intraoperative cytological examination of ascitic fluid were performed. Cytological study of ascitic fluid revealed that abundant granular cell debris, degenerative cells and apoptotic bodies were present, as well as some single or multinucleated cells with ground glass nuclei. However, vivid mesothelial cells were rarely seen. Immunocytochemical staining for type II HSV was positive in single or multinucleated cells with ground glass nuclei. Therefore, a diagnosis of type II HSV peritonitis was made. This is the first reported case of type II HSV peritonitis successfully diagnosed by ascitic cytology. This report highlights that the presence of abundant cell debris, degenerative cells and apoptotic bodies, and the absence of vivid mesothelial cells are the key cytological findings to suspect HSV peritonitis, and the diagnosis can be confirmed by careful surveillance for characteristic nuclear findings of single or multinucleated cells. The frequency of opportunistic infection is increased because of the increased numbers of iatrogenic immunocompromised patients as seen in this case, therefore, cytological examination is a useful method for early detection of the causative agent of peritonitis including HSV.

Cytological features of myxoid adrenocortical adenoma with a pseudoglandular component: a case report with differential diagnostic considerations.

Myxoid adrenocortical tumors are extremely rare neoplasms with only nine adenomas and eleven carcinomas reported in the literature. They occasionally have a pseudoglandular component resembling metastatic mucinous adenocarcinoma in the adrenal gland. However the cytological features of this unusual tumor have not been previously described. We report here the first cytopathological study of a myxoid adrenocortical adenoma with a pseudoglandular component, contributing especially to the differential diagnosis from metastatic mucinous adenocarcinoma. Two major cytopathological features distinguishing myxoid adrenocortical adenoma from metastatic mucinous adenocarcinoma in the adrenal gland are: (1) the myxoid material is found only in the extracellular space, and not in the cytoplasm; and (2) nuclei are usually located in the central portion of the cytoplasm, and not compressed to the periphery. Careful observation of these cytological features and positive immunoreactivity to Melan A, alpha-inhibin and synaptophysin can lead to the correct diagnosis.