Spectral clustering algorithm for the allometric extension model

The spectral clustering algorithm is often used as a binary clustering method for unclassified data by applying the principal component analysis. To study theoretical properties of the algorithm, the assumption of conditional homoscedasticity is often supposed in existing studies. However, this assumption is restrictive and often unrealistic in practice. Therefore, in this paper, we consider the allometric extension model, that is, the directions of the first eigenvectors of two covariance matrices and the direction of the difference of two mean vectors coincide, and we provide a non-asymptotic bound of the error probability of the spectral clustering algorithm for the allometric extension model. As a byproduct of the result, we obtain the consistency of the clustering method in high-dimensional settings.Comment: 20 page

A Clinicopathological Study of Primary Small Intestinal Cancer with Emphasis on Cellular Characteristics

We examined the clinicopathological profiles and cellular characteristics of 10 cases of surgically resected primary small intestinal cancers (excluding duodenal cancers). Histological examination revealed nine adenocarcinomas and one sarcomatoid carcinoma. Invasion depth was subserosal in five cases, serosal in four cases and to the adjacent transverse colon in the remaining case. Metastasis was present in lymph node in seven cases, in distant organs in six, and in the peritoneum in seven cases. Of the 10 cases, 7 underwent postoperative chemotherapy, and 6 of the eight traceable patients died from the disease (mean period of survival: 386 days). Histomorphologically, eight of nine adenocarcinomas showed an intestinal phenotype (unclassifiable in the other) in the upper layer, while in the lower layer, there showed an intestinal phenotype and five a non-intestinal phenotyp. Immunohistochemistry revealed a mean positive rate in the upper/lower layers as follows: 93%/86% and 38%/29% by intestinal markers CDX2 and MUC2; 19%/28% and 13%/32% by pancreatobiliary markers CK7 and MUC1; and 4%/19% and 2%/9% by gastric markers MUC5AC and MUC6, respectively. Thus, the intestinal phenotype predominated in almost all small intestinal cancer in this study, although some showed a transformation to non-intestinal or hybrid phenotypes with tumor progression. Flexible management for the diversity and transformation of cellular characteristics is therefore recommended treating and diagnosing small intestinal cancers

Clinicopathological Significance of FOXP3 Expression in Esophageal Squamous Cell Carcinoma

The expression of transcription factor forkhead box protein 3 (FOXP3), a master control gene for regulatory T cells, has been reported to influence patient survival. However, there have been few reports of the relationship between FOXP3 positive cells and esophageal squamous cell carcinoma (ESCC). The aim of this study was to clarify the prognostic value of FOXP3 expression in ESCC. Ninety-five patients who were diagnosed with primary ESCC and underwent subtotal esophagectomy during 2009 and 2010 were retrospectively analyzed. Deepest sections from each tumor were selected for immunohistochemistry and the number of FOXP3 positive cells was counted. The median number was used as a cutoff to divide into FOXP3 positive and FOXP3 negative subgroups. Relationships between FOXP3 expression and clinicopathological features, disease-free survival (DFS) and overall survival (OS) were determined. Statistical values of p < 0.05 were considered significant. FOXP3 positive cells were found in all 95 cases and the number of FOXP3 positive cells was significantly higher in the peri-tumor compartment than in the intra-tumor compartment (p = 0.0006). For this reason, the peri-tumor compartment numbers were used for all of the association studies. Results showed that the FOXP3 positive group had a significantly larger mean tumor size (43.8 ± 4.1mm vs 29.1 ± 4.0mm, p = 0.0055), and the FOXP3 negative group had a significantly higher percentage of deep invasion (T2, T3, T4)(p = 0.0399). There was no significant association for DFS, however, for OS the FOXP3 positive group demonstrated a significantly better prognosis (p = 0.0024). Multivariate analysis showed that peri-tumor FOXP3 expression is an independent prognostic factor for OS (p = 0.0035). Peri-tumoral FOXP3 expression is an independent and favorable prognostic factor for ESCC

Ganglioside GM3 Has an Essential Role in the Pathogenesis and Progression of Rheumatoid Arthritis

Rheumatoid arthritis (RA), a chronic systemic inflammatory disorder that principally attacks synovial joints, afflicts over 2 million people in the United States. Interleukin (IL)-17 is considered to be a master cytokine in chronic, destructive arthritis. Levels of the ganglioside GM3, one of the most primitive glycosphingolipids containing a sialic acid in the structure, are remarkably decreased in the synovium of patients with RA. Based on the increased cytokine secretions observed in in vitro experiments, GM3 might have an immunologic role. Here, to clarify the association between RA and GM3, we established a collagen-induced arthritis mouse model using the null mutation of the ganglioside GM3 synthase gene. GM3 deficiency exacerbated inflammatory arthritis in the mouse model of RA. In addition, disrupting GM3 induced T cell activation in vivo and promoted overproduction of the cytokines involved in RA. In contrast, the amount of the GM3 synthase gene transcript in the synovium was higher in patients with RA than in those with osteoarthritis. These findings indicate a crucial role for GM3 in the pathogenesis and progression of RA. Control of glycosphingolipids such as GM3 might therefore provide a novel therapeutic strategy for RA