Masahiko Shibata

Circulating IgA and IgE autoantibodies in antilaminin-332 mucous membrane pemphigoid

Background  Antilaminin‐332 mucous membrane pemphigoid (MMP) is a chronic autoimmune bullous disease that is often associated with internal malignancy. IgG autoantibodies against laminin‐332 in patients with MMP are well documented; however, IgA and IgE autoantibodies against laminin‐332 have not yet been described.

TISSUE-SPECIFIC HIGH-LEVEL EXPRESSION OF HUMAN ENDOGENOUS RETROVIRUS-R IN THE HUMAN ADRENAL CORTEX

In an attempt to clarify the biological nature of a human endogenous retrovirus (HERV), HERV-R, which is a single-copy type of HERVs and is conserved as a full-length viral sequence, the expression of HERV-R mRNA in normal autopsied systemic organs was examined by Northern blot analysis. The expression showed different levels among individuals, with the adrenal glands expressing the highest level of HERV-R among all organs tested, except for the placenta. In various adrenal tumors, HERV-R was expressed at high levels in all cortical adenomas but less so in pheochromocytomas. In situ hybridization revealed the expression of HERV-R to be localized in all layers of the adrenal cortex, but not in the medulla. This high-level expression of HERV-R in the adrenal cortex may possibly relate to differentiation and/or steroid production by adrenocortical cells.

Analyses of Matrix Metalloproteinases and Their Inhibitors in Cyst Fluid of Serous Ovarian Tumors

Objectives: Expression of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) in serous tumors of the ovary was investigated to determine whether and how these proteolytic enzymes are associated with the progression of these tumors. Methods: Cyst fluid of 24 serous ovarian tumors (8 adenocarcinomas, 2 borderline tumors and 14 adenomas) was analyzed using gelatin/casein zymography and enzyme-linked immunosorbent assay. Results: Concentrations of MMP-9 and MMP-2 were statistically higher in serous adenocarcinomas than in serous adenomas (p < 0.01, p < 0.05, respectively), while the concentrations of TIMP-1 and TIMP-2 showed no significant difference between adenocarcinomas and adenomas. The molar ratio of TIMP-2/MMP-2 was lower in adenocarcinomas than in adenomas (p < 0.05). With gelatin zymography, the MMP-9 band was detected in all serous adenocarcinomas, but only in 8 of 14 serous adenomas (p = 0.05). Using casein zymography, MMP-7 was more frequently detected in serous adenocarcinomas (7/8) than in serous adenomas (4/14; p < 0.05). Conclusions: These observations indicate that matriolytic enzymes such as MMP-2, MMP-7 and MMP-9 are secreted into cyst fluid from serous adenocarcinoma tissues. In part, the aggressive invasion of serous carcinoma cells may be explained by the expression of matriolytic enzymes.

The Role of the Thymus in Development of Necrotizing Arteritis in Transgenic Rats Carrying the env-pX Gene of Human T-Cell Leukemia Virus Type-I

Necrotizing arteritis mimicking polyarteritis nodosa occurred in transgenic rats carrying the env-pX gene of human T-cell leukemia virus type I. To investigate the pathogenesis of necrotizing arteritis in these rats (env-pX rats), adoptive transfers of spleen cells and bone marrow cells were done from env-pX rats before they developed arteritis to nontransgenic rats. Necrotizing arteritis occurred in lethally irradiated nontransgenic rats reconstituted by env-pX spleen cells, thus indicating that the env-pX transgene in affected vessels may not be essential for the development of arteritis. In contrast, arteritis was not induced in nontransgenic recipients by adoptive transfers of env-pX bone marrow cells, which suggested that T cells derived from the env-pX thymus may play a role in the development of arteritis. To clarify if the process of differentiation of T cells in the env-pX thymus is crucial to develop necrotizing arteritis, reciprocal exchange of thymus frameworks was done between env-pX and nontransgenic rats. Necrotizing arteritis occurred in nontransgenic rats with an env-pX thymus framework, whereas development of arteritis was suppressed in env-pX rats in which the thymus framework was replaced with a nontransgenic one. This collective evidence shows that the thymus is directly associated with the development of necrotizing arteritis in env-pX rats.

Combined hepatocellular carcinoma and cholangiocarcinoma growing into the common bile duct

We report a patient with combined hepatocellular carcinoma and cholangiocarcinoma (HCC-CC) growing into the common bile duct (CBD) and showing obstructive jaundice within 2 years of the onset of the disease. The patient was a 59-year-old Japanese man in whom, at the age of 57 years. a hepatic tumor was discovered by diagnostic imaging during follow-up of hepatitis B surface antigen (HBsAg)-positive liver cirrhosis. The tumor was diagnosed as HCC. Epirubicin was injected twice, intraarterially. The patient then received oral etoposide therapy for the next 14 months. The treatment was initially effective, but approximately 2 years after the hepatic tumor was discovered, local recurrence of the tumor and a tumor thrombus in the CBD were discovered. Although he was treated with percutaneous transhepatic biliary drainage (PTBD), to reduce obstructive jaundice, the jaundice was irreversible and he died of severe hepatic failure. The autopsy findings confirmed that the hepatic tumor was HCC-CC, in which the HCC and CC components expressed alpha-fetoprotein (AFP) and carbohydrate antigen 19-9 (CA19-9), respectively, which accurately reflected the disease process. The underlying mechanism of the growth of HCC-CC into the CBD may differ from the underlying mechanism of the development of icteric-type HCC.

Endocrine cell micronests in an ovarian mucinous cystadenofibroma : A mimic of microinvasion

An ovarian mucinous cystadenofibroma with peculiar neuroendocrine cell micronests is described in a 59-year-old Japanese woman. Aggregates of epithelial cells resembling microinvasive carcinoma cells were scattered throughout the adenofibromatous area. These micronests were composed of small uniform cells with argentaffin and argyrophil granules. Numerous small cells with neuroendocrine granules were also seen within mucinous glands. This is the first report of neuroendocrine micronests in an ovarian neoplasm, a finding that should be distinguished from microinvasion.

Spontaneous Remission of Solitary-Type Infantile Myofibromatosis

Infantile myofibromatosis is a rare fibrous tumor of infancy. The cutaneous solitary type has typically an excellent prognosis. However, histologically, it is important to rule out leiomyosarcoma, which has a poor prognosis. The low frequency of mitosis was definitive for a diagnosis of infantile myofibromatosis. We present a cutaneous solitary-type case of infantile myofibromatosis. Following incisional biopsy, the tumor remitted spontaneously.