Toshinori Oinuma

Quantitative analysis of human tissue-specific differences in methylation

Tissue-specific differentially methylated regions (tDMRs) have been identified and implicated for their indispensable involvement in mammalian development and tissue differentiation. In this report, a quantitative DNA methylation analysis was performed for 13 human orthologous regions of recently confirmed mouse tDMRs by using Sequenom Mass Array, by which bisulfite-treated fragments are quantitatively detected using time of flight mass spectroscopy analysis. Eight regions were shown as tDMRs in various tissues from three independent individuals. Testis DNA samples from eight individuals were also analyzed for methylation. Interestingly, there is evidence that the DNA methylation level is divergent among individuals. DNA methylation levels of five testis-specific DMRs were significantly inversely correlated with the number of spermatocytes. However, a positive correlation was seen at tDMRs located near the TRIM38 and CASZ1 genes. Our results indicate that tDMRs are conserved between mouse and human and may have an important role in regulating tissue function, differentiation, and aging.

Sclerosing Encapsulating Peritonitis: Regional Changes of Peritoneum

Sclerosing encapsulating peritonitis (SEP) is characterized by the diffuse appearance of marked sclerotic thickening of the peritoneal membrane. We experienced a case with SEP accompanied by regional changes of peritoneum. A 37-year-old woman with end-stage renal failure was started on continuous ambulatory peritoneal dialysis in 1985 and was transferred to hemodialysis in 1997. She was admitted because of ileus in 1998 with SEP and died of septicemia. The diagnosis of SEP was confirmed via the autopsy. The root of the mesentery was retracted and shortened. Since the peritoneal change was marked in the regions with free margin of mesentery and was less apparent in the regions not adhered to mesentery, it is indicated that mechanical stress also contributes to the occurrence of SEP. Since calcification and ossification were only seen in a free margin of small bowel from mesentery, it is suggested that there is a close relationship between calcification and ossification. Since fibrosis invaded into the muscle layer, dysfunction of bowel movement as well as bowel obstruction contributed to the appearance of ileus. It is suggested that mechanical stress by the root of mesentery which is retracted and shortened also contributes to the appearance of SEP.

Creutzfeldt-Jakob disease with florid plaques after cadaveric dura mater graft.

A patient with dura‐associated Creutzfeldt‐Jakob disease (D‐CJD) which occurred about 15 years after a dura mater graft is reported in the present study. The prion protein gene analysis disclosed no mutation. The D‐CJD was atypical in: (i), the long interval between the onset of ataxia and the occurrence of dementia; (ii), the presence of transient myoclonus; and (iii), the presence of florid plaques in the brain. The electron‐microscopic findings showed bundles of amyloid filaments which radiated from the center of the plaques without degenerating neurites. This case of D‐CJD may belong to a new subtype of D‐CJD.

Overexpression of anti-apoptotic Mcl-1 in testicular germ cell tumours

Aims:  To determine the expression of Mcl‐1 in testicular germ cell tumours in order to clarify the role of this anti‐apoptotic factor in these tumours. Various members of the Bcl‐2 family have been implicated in the apoptotic mechanisms regulating germ cell apoptosis. Mcl‐1 is an anti‐apoptotic Bcl‐2 family member and has recently been reported to be related to the progression of malignancy; however, the involvement of Mcl‐1 in the development of germ cell tumours is still unknown.

An impending rupture of a celiac artery aneurysm in a patient with Behçet’s disease — Extra-anatomic aorto-common hepatic artery bypass: Report of a case

A celiac artery aneurysm associated with Behçet’s disease is extremely rare. We herein present the case of successful surgical treatment for an impending rupture of a large celiac artery aneurysm with a wide proximal neck in a patient associated with Behçet’s disease. To our knowledge, this is the first report of a procedure involving extra-anatomic aorto-common hepatic artery (CHA) bypass through the retroperitoneal space implanting a 6-mm expanded polytetrafluoroethylene graft. An 18-month postoperative magnetic resonance angiography scan showed a good patency of the aorto-CHA graft without an anastomotic pseudoaneurysm in a closure of aorta and anastomoses.

Expression of Peroxisome Proliferator-Activated Receptor Subtypes in Human Atherosclerosis

Abstract: To clarify the involvement of peroxisome proliferator‐activated receptors (PPARs) in atherosclerotic plaque formation, we investigated the expression patterns of mRNA and protein of PPARα and PPARγ in human aorta. Atheromatous plaque, fatty streak, and diffuse intimal thickening (DIT) were separated macroscopically, and each sample was divided into halves. Half of them were used for analysis of mRNA expression with reverse transcription‐polymerase chain reaction and the others were used for histologic analysis. Both PPARα and PPARγ mRNA were detected in all atheromatous plaques, all fatty streaks, and in some DIT. However, expressions of PPARα and PPARγ were obviously less frequently found in DIT than in atheromatous plaques, and the intensity of these expressions was stronger in the atheromatous plaques than in the DIT. Compared with PPARα, PPARγ mRNA was expressed more frequently in atheromatous plaques. In atheromatous plaques, PPARγ mRNA was expressed independently, whereas PPARα mRNA was coexpressed with PPARγ. PPARγ protein was obviously found in the nuclei of endothelial cells, macrophages, mononuclear cells, and smooth muscle cells in the aortic intima. These results suggest that expressions of PPARα and PPARγ in human aortic wall are involved in atherogenesis from the early stages.

Semi-Nested Real-Time Reverse Transcription Polymerase Chain Reaction Methods for the Successful Quantitation of Cytokeratin mRNA Expression Levels for the Subtyping of Non-Small-Cell Lung Carcinoma Using Paraffin-Embedded and Microdissected Lung Biopsy Specimens

In patients with inoperable advanced non-small cell lung carcinomas (NSCLCs), histological subtyping using small-mount biopsy specimens was often required to decide the indications for drug treatment. The aim of this study was to assess the utility of highly sensitive mRNA quantitation for the subtyping of advanced NSCLC using small formalin fixing and paraffin embedding (FFPE) biopsy samples. Cytokeratin (CK) 6, CK7, CK14, CK18, and thyroid transcription factor (TTF)-1 mRNA expression levels were measured using semi-nested real-time quantitative (snq) reverse-transcribed polymerase chain reaction (RT-PCR) in microdissected tumor cells collected from 52 lung biopsies. Our results using the present snqRT-PCR method showed an improvement in mRNA quantitation from small FFPE samples, and the mRNA expression level using snqRT-PCR was correlated with the immunohistochemical protein expression level. CK7, CK18, and TTF-1 mRNA were expressed at significantly higher levels (P<0.05) in adenocarcinoma (AD) than in squamous cell carcinoma (SQ), while CK6 and CK14 mRNA expression was significantly higher (P<0.05) in SQ than in AD. Each histology-specific CK, particularly CK18 in AD and CK6 in SQ, were shown to be correlated with a poor prognosis (P=0.02, 0.02, respectively). Our results demonstrated that a quantitative CK subtype mRNA analysis from lung biopsy samples can be useful for predicting the histology subtype and prognosis of advanced NSCLC.

Coexpression of an unusual form of the EWS–WT1 fusion transcript and interleukin 2/15 receptor βmRNA in a desmoplastic small round cell tumour

Background: The β chain of the interleukin 2/15 receptor (IL-2/15Rβ) is induced by the expression of the EWS–WT1. A case of desmoplastic small round cell tumour (DSRCT) expressing only an unusual EWS-WT1 treated by us is reported here. Aim: To characterise an unusual form of EWS–WT1. Methods: Frozen tissue sections of the axillary tumour were examined using a laser-assisted microdissection technique and reverse transcriptase polymerase chain reaction. Results: The novel fusion of exon 8 of EWS and the defective exon 10 of WT1 (−KTS) was detected. Although it was an unusual form, the coexpression of the present EWS–WT1, IL-2/15Rβ and Janus kinase (JAK1) mRNA was detected in the tumour cells. IL-2 and signal transducers and activators of transcription (STAT5) mRNA were detected in both tumour and stromal cells. Conclusion: The induction of the IL-2/15 receptor signalling pathway may contribute to tumorigenesis in DSRCT through a paracrine or an autocrine system, even though the EWS–WT1 was an unusual form.

Two Cases of Primary Malignant Fibrous Histiocytoma of the Liver: Immunohistochemical Expression of Ezrin and Its Relationship with Prognosis

Malignant fibrous histiocytoma (MFH) as soft tissue sarcoma would not be especially noteworthy, but primary hepatic MFH reports are extremely rare. Herein, we report ezrin expression in tumor tissues from two primary hepatic MFH cases with different prognoses. Cases 1 and 2 were both women, ages 45 and 70 years, respectively. Case 1 had an 11×10 cm liver tumor in segment (S) 3, and case 2 had two liver tumors, 12×8 cm in S5 and 10×7 cm in S8. Neither had any other systemic tumors. Cases 1 and 2 survived for two year and ten months and for eight and a half months, respectively, after the initial tumor resection. Microscopically, the tumors of these two cases were similar and showed proliferation of atypical cells, including spindle, pleomorphic and multi-nucleated giant cells arranged in storiform, sheet and/or fascicle patterns, with scattered foci of inflammatory cells, indicating MFH. Ezrin expression in tumor tissue from case 1 was sparse, whereas that of case 2 showed strong ezrin expression in many tumor cells. The present results indicate ezrin immunoreactivity in primary hepatic MFH to correlate possible with prognosis, which is consistent with reports on some other types of malignancies.

Correlation of two argyrophilic nucleolar organizer region counting methods with the Ki-67 labeling index in uterine smooth muscle cell tumors

The argyrophilic nucleolar organizer regions (AgNOR) are silver stained granules that are thought to correlate with cell proliferation activity. Two AgNOR counting methods: the mean AgNOR count (mAgNOR, the mean number of AgNOR granules in 100 cells) and the AgNOR proliferatlve Index (pAgNOR, the percentage of cells exhibiting five or more AgNOR granules per nuclei) have been proposed. In this study, the two counting methods were applied to 58 cases of normal uterine corpus and uterine corpus tumors and were compared with the Ki‐67 labeling Index (Ki‐67 Ll) using MIB‐1 monoclonal antibody and other hlstopathologlcal criteria. Notable differences In the number of AgNOR and the Ki‐67 Ll were observed between benign and malignant smooth muscie tissue. Hlstopathologic features are well correlated to the proliferatlve activity of tumors. Although the most reliable method of predicting malignant potential cannot be determined, the methods outlined by this study are thought to be highly useful In assessing proliferatlve activities.