Differential expression of mucin core proteins and keratins in apocrine carcinoma, extramammary Paget's disease and apocrine nevus.

BACKGROUND: Apocrine carcinomas are rare, the immunohistochemical characterizations that are incomplete. The purpose of this study was to determine the immunohistochemical characteristics of mucin core proteins and keratins in apocrine carcinoma, extramammary Paget's disease (EMPD) and apocrine nevus. METHODS: We report four cases of apocrine carcinomas along with immunohistochemical analyses: (i) an axillary apocrine carcinoma with an apocrine nevus, (ii) an inguinal apocrine carcinoma, (iii) a vulvar apocrine carcinoma with EMPD and (iv) an axillary apocrine carcinoma with EMPD and an apocrine nevus. RESULTS: The tumor cells of apocrine carcinomas, EMPD and apocrine nevi displayed a positive reaction to MUC-1 and CK7 and a negative reaction to CK20. Apocrine carcinomas had high molecular weight (HMW) cytokeratin(+)/CK5(+)/CK14(-)/MUC5AC(-), EMPD with underlying apocrine carcinoma had HMW cytokeratin(-)/CK5(-)/CK14(-)/MUCA5AC(-) and the apocrine nevi had HMW cytokeratin(+)/CK5(+)/CK14(+)/MUCA5AC(+). CONCLUSION: The immunohistochemical findings suggest that apocrine carcinomas, apocrine nevi and EMPD with underlying apocrine carcinomas are quite different, even though they are all derived from apocrine glands.

Age-dependent changes of postischemic reperfusion in rat skin.

Ischemia-reperfusion plays a certain role in causing skin damage associated with pressure sores. In this study, changes in cutaneous hemodynamics during reperfusion were investigated in young and older rats. After cessation of 1-hour or 2-hour ischemia, the skin blood flow increased transiently (postischemic hyperemia) and quickly returned to the baseline in young and older rats. After 4-hour ischemia, however, the postischemic hyperemia was reduced in both groups, and the skin blood flow decreased below the baseline for a few hours in older rats. The skin blood flow tolerated well the repeated exposures to 1-hour ischemia in both groups. In 2-hour ischemia experiments, the postischemic hyperemia was preserved after the second ischemic period in young rats but not in older rats. These results suggest that the tolerance of skin microcirculation to ischemia-reperfusion may decrease with increasing age.

Effects of head-down tilt on cerebral blood flow and somatosensory-evoked potentials in rabbits.

Changes in cerebral blood flow (CBF) and somatosensory-evoked potentials (SEPs) were studied in rabbits exposed to head-down tilt (HDT) at 45 degrees and 75 degrees. The animals were anesthetized with alpha chloralose and the lungs were artificially ventilated. CBF was continuously measured by laser Doppler flowmetry (LDF), and SEPs were recorded as responses of the cortex to median nerve stimulation. In the 45 degrees HDT rabbits, CBF did not change significantly in the parietal cortex during 1 h of HDT. In contrast, in the 75 degrees HDT rabbits, CBF did not change significantly within 5 min after the onset of HDT, but decreased gradually to 79% of the pre-HDT baseline value at the end of 1 h of HDT. The latency and amplitude of SEPs did not change significantly throughout the experiment in any group. These results suggest that CBF and SEPs do not change significantly during 1 h of 45 degrees HDT and that 75 degrees HDT disturbs the regulation of the cerebral circulation but does not affect cortical somatosensory response, at least for 1 h.

Effects of head-down tilt on cerebral blood flow in humans and rabbits.

Changes in cerebral hemodynamics, during and after head down tilt (HDT), were examined by means of transcranial Doppler technique (TCD) and near infrared spectroscopy (NIRS) in humans, and laser Doppler flowmetry (LDF) in rabbits. Mean cerebral blood flow (CBF) velocity measured by TCD increased during the first 6 h of HDT compared with the pre-HDT value. NIRS experiments demonstrated that brain oxygenation and hemoglobin concentration increased with postural change from upright to supine. These results suggest that exposure to HDT increases CBF during the early phase of HDT in humans. In rabbits anesthetized with alpha chloralose, on the other hand, 45 degrees HDT did not change CBF significantly in the parietal cortex during 1 h after the onset of HDT. The discrepancy may be explained by the difference in species, tilt angle, or the brain region where CBF has been measured.