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Biomedical subjects

M Ikezu

Publications and source records attributed to M Ikezu.

3 recordsLinked to original sources

Splenic hemangiosarcoma with sinus endothelial differentiation.

A case of primary splenic hemangiosarcoma where the tumors entirely replaced the spleen is reported. Histologically, the splenic tumors consisted of two major components: (i) solid and nodular areas, in which spindle cells (SC) were arranged in interlacing fascicles; and (ii) vasoformative areas, in which vascular lining cells (VC) closely resembled normal splenic sinus endothelial cells (SSEC) in shape. Both SC and VC were immunoreactive with the markers of vascular endothelial cells (EC) including SSEC, JC70, von Willebrand factor, OKM5, vimentin MAb and Ulex europaeus-1 lectin. The tumor cells were positive for OKM5 MAb as well as normal SSEC and sheathed arterial EC, but other vascular EC in normal spleen were negative. Enzyme-histochemically, the tumor cells and normal SSEC revealed naphthol AS-D acetate esterase activity but no reaction for ALPase, whereas normal vascular EC other than SSEC in the spleen were positive for the latter but negative for the former. These studies revealed that the tumor cells expressed the same phenotype as normal SSEC. To the present author's knowledge this is the first report demonstrating sinus endothelial differentiation of splenic hemangiosarcoma, enzyme- and immuno-histochemically.

Aged↗

Cardiac rhabdomyoma. A case report with reference to atrial natriuretic peptide.

An autopsy case of cardiac rhabdomyoma in a male infant is reported. Many nodules of rhabdomyoma were present in all four cardiac chambers and were microscopically composed of ovoid, glycogen-laden cells and typical "spider cells". Atrial natriuretic peptide (ANP) was immunohistochemically demonstrated in both normal myocytes and rhabdomyoma cells of both atria, but not in normal myocytes and rhabdomyoma cells of both ventricles. Ultrastructurally, atrial specific granules were present in atrial rhabdomyoma cells and normal atrial cardiocytes, and these showed ANP immunoreactivity with protein A-gold technique. It could be said that the localization and intracellular distribution of ANP in this cardiac rhabdomyoma were closely similar to those of normal human heart. With regard to the presence of ANP, cardiac rhabdomyoma cells arising in atria seemed to differ from those in ventricles, although many tumor nodules occurred in both atria and ventricles. Furthermore, it seemed that cardiac rhabdomyomas could also be divided into two parts: 1) an atrial part with ANP, and 2) a ventricular part without ANP. Therefore, this study confirms the hypothesis that cardiac rhabdomyoma is a hamartoma rather than a true neoplasm.

Atrial Natriuretic Factor↗

Immunohistochemical demonstration of peptide YY in gastrointestinal endocrine tumors.

Fourteen cases of gastrointestinal endocrine tumors were examined immunohistochemically for peptide YY, pancreatic polypeptide, glucagon, and somatostatin. Peptide YY cells were present in seven tumors, pancreatic polypeptide cells in eight tumors, glucagon cells in six tumors, and somatostatin cells in nine tumors. All 7 rectal endocrine tumors examined were found to contain peptide YY, while in the tumors of the other sites peptide YY cells were not detected. Peptide YY cell population in the rectal tumors was small to moderate in comparison with pancreatic polypeptide and glucagon cell population. This study suggests that peptide YY cells may be a common constituent of rectal endocrine tumors together with pancreatic polypeptide and glucagon cells, and that the peptide YY spectrum of gastrointestinal endocrine tumors may be closely related to the location of the tumors. Moreover, it can also be said that peptide YY may be used as one of the markers of rectal endocrine tumors.

Adolescent↗