Asymptotic Optimality of Antidictionary Codes

An antidictionary code is a lossless compression algorithm using an antidictionary which is a set of minimal words that do not occur as substrings in an input string. The code was proposed by Crochemore et al. in 2000, and its asymptotic optimality has been proved with respect to only a specific information source, called balanced binary source that is a binary Markov source in which a state transition occurs with probability 1/2 or 1. In this paper, we prove the optimality of both static and dynamic antidictionary codes with respect to a stationary ergodic Markov source on finite alphabet such that a state transition occurs with probability $p (0 < p \leq 1)$.Comment: 5 pages, to appear in the proceedings of 2010 IEEE International Symposium on Information Theory (ISIT2010

Two-Dimensional Source Coding by Means of Subblock Enumeration

A technique of lossless compression via substring enumeration (CSE) attains compression ratios as well as popular lossless compressors for one-dimensional (1D) sources. The CSE utilizes a probabilistic model built from the circular string of an input source for encoding the source.The CSE is applicable to two-dimensional (2D) sources such as images by dealing with a line of pixels of 2D source as a symbol of an extended alphabet. At the initial step of the CSE encoding process, we need to output the number of occurrences of all symbols of the extended alphabet, so that the time complexity increase exponentially when the size of source becomes large. To reduce the time complexity, we propose a new CSE which can encode a 2D source in block-by-block instead of line-by-line. The proposed CSE utilizes the flat torus of an input 2D source as a probabilistic model for encoding the source instead of the circular string of the source. Moreover, we analyze the limit of the average codeword length of the proposed CSE for general sources.Comment: 5 pages, Submitted to ISIT201

A Universal Two-Dimensional Source Coding by Means of Subblock Enumeration

The technique of lossless compression via substring enumeration (CSE) is a kind of enumerative code and uses a probabilistic model built from the circular string of an input source for encoding a one-dimensional (1D) source. CSE is applicable to two-dimensional (2D) sources, such as images, by dealing with a line of pixels of a 2D source as a symbol of an extended alphabet. At the initial step of CSE encoding process, we need to output the number of occurrences of all symbols of the extended alphabet, so that the time complexity increases exponentially when the size of source becomes large. To reduce computational time, we can rearrange pixels of a 2D source into a 1D source string along a space-filling curve like a Hilbert curve. However, information on adjacent cells in a 2D source may be lost in the conversion. To reduce the time complexity and compress a 2D source without converting to a 1D source, we propose a new CSE which can encode a 2D source in a block-by-block fashion instead of in a line-by-line fashion. The proposed algorithm uses the flat torus of an input 2D source as a probabilistic model instead of the circular string of the source. Moreover, we prove the asymptotic optimality of the proposed algorithm for 2D general sources

Aberrant Expression of TFF1, TFF2, and PDX1 and Their Diagnostic Value in Lobular Endocervical Glandular Hyperplasia

Lobular endocervical glandular hyperplasia (LEGH) is a distinct benign glandular lesion expressing gastric gland mucous cell-type mucin (N-acetylglucosaminal -> 4galactose -> R [GlcNAc alpha 1 -> 4Gal -> R]). To investigate histogenesis and diagnostic markers of LEGH, we examined the immunohistochemical expression profile of gastric surface mucous cell (MUC5AC and TFF1), gastric gland mucous cell (MUC6, TFF2, and GlcNAc alpha 1 -> 4Gal -> R), gastric pyloric epithelial cell (PDX1), and endocervical cell (keratan sulfate) markers in normal endocervix samples and benign glandular lesions (nabothian cysts, tunnel clusters, and LEGHs). MUC5AC and MUC6 were expressed in normal endocervical mucosa and benign glandular lesions. TFF1, TFF2, GlcNAc alpha 1 -> 4Gal -> R, and PDX1 were expressed only in LEGH. Keratan sulfate was expressed in normal endocervical mucosa and benign glandular lesions. In LEGH, gastric surface mucous cell and gastric gland mucous cell differentiation were demonstrated, and transdifferentiation from endocervical mucosa into gastric pyloric mucosa was suggested. In addition to GlcNAc alpha 1 -> 4Gal -> R, TFF1, TFF2, and PDX1 are additional useful markers for LEGH.ArticleAMERICAN JOURNAL OF CLINICAL PATHOLOGY. 135(2):253-261 (2011)journal articl

Distinct Cytoplasmic Expression of KL-6 Mucin in Chromophobe Renal Cell Carcinoma: A Comparative Immunohistochemical Study with Other Renal Epithelial Cell Tumors

信州大学博士（医学）・学位論文・平成25年1月30日授与（乙第1152号）・福島 万奈The presence of cytoplasmic sialyl glycoproteins is a conspicuous feature in chromophobe renal cell carcinoma (RCC). We compared the immunohistochemical expression of sialyl glycoproteins in chromophobe RCC with that in other types of renal tumors. Formalin-fixed, paraffin-embedded tissues of surgically resected renal tumors (chromophobe RCC, 14 cases [10 cases of classic type and 4 cases of eosinophilic variant]; oncocytoma, 7 cases; and clear cell RCC, 9 cases) and kidneys from immature infants (4 cases) were immunostained with antibodies against sialyl glycoproteins (anti-KL-6 and anti-sialyl MUC1 antibodies). Cytoplasmic expression of KL-6 and sialyl MUC1 was distinctive in the chromophobe RCC and renal oncocytoma cells, and in the intercalated cells in collecting duct epithelia. Apical-surface staining of these sialyl glycoproteins was predominantly observed in clear RCC, in the epithelia of the distal tubule and collecting duct, and in the neonatal renal proximal tubule, but not in those of the adult renal proximal tubule. The above-mentioned observations provide additional evidence for similar phenotypic profiles of chromophobe RCC and renal oncocytoma, and the intercalated cells in collecting ducts and the oncofetal expression of sialyl glycoproteins in clear cell RCC. KL-6 is a potential tumor marker for renal tumors.ArticleACTA HISTOCHEMICA ET CYTOCHEMICA. 45(5) 301-308 (2012)journal articl

Compression by Substring Enumeration Using Sorted Contingency Tables

This paper proposes two variants of improved Compression by Substring Enumeration (CSE) with a finite alphabet. In previous studies on CSE, an encoder utilizes inequalities which evaluate the number of occurrences of a substring or a minimal forbidden word (MFW) to be encoded. The inequalities are derived from a contingency table including the number of occurrences of a substring or an MFW. Moreover, codeword length of a substring and an MFW grows with the difference between the upper and lower bounds deduced from the inequalities, however the lower bound is not tight. Therefore, we derive a new tight lower bound based on the contingency table and consequently propose a new CSE algorithm using the new inequality. We also propose a new encoding order of substrings and MFWs based on a sorted contingency table such that both its row and column marginal total are sorted in descending order instead of a lexicographical order used in previous studies. We then propose a new CSE algorithm which is the first proposed CSE algorithm using the new encoding order. Experimental results show that compression ratios of all files of the Calgary corpus in the proposed algorithms are better than those of a previous study on CSE with a finite alphabet. Moreover, compression ratios under the second proposed CSE get better than or equal to that under a well-known compressor for 11 files amongst 14 files in the corpus

Gastric Composite Tumor of Alpha Fetoprotein-Producing Carcinoma/Hepatoid Adenocarcinoma and Endocrine Carcinoma with Reference to Cellular Phenotypes

Alpha-fetoprotein-producing carcinoma (AFPC)/hepatoid adenocarcinoma (HAC) and neuroendocrine carcinoma (NEC) are uncommon in the stomach. Composite tumors consisting of these carcinomas and their histologic phenotypes are not well known. Between 2002 and 2007, to estimate the prevalence of composite tumors consisting of tubular adenocarcinoma, AFPC/HAC and NEC, we reviewed specimens obtained from 294 consecutive patients treated surgically for gastric cancer. We examined histological phenotype of tumors of AFPC or NEC containing the composite tumor by evaluating immunohistochemical expressions of MUC2, MUC5AC, MUC6, CDX2, and SOX2. Immunohistochemically, AFPC/HAC dominantly showed the intestinal or mixed phenotype, and NEC frequently showed the gastric phenotype. In the composite tumor, the tubular and hepatoid components showed the gastric phenotype, and the neuroendocrine component showed the mixed type. The unique composite tumor predominantly showed the gastric phenotype, and the hepatoid and neuroendocrine components were considered to be differentiated from the tubular component

A Case of Primary Signet-Ring Cell/Histiocytoid Carcinoma of the Eyelid: Immunohistochemical Comparison With the Normal Sweat Gland and Review of the Literature

Primary signet-ring cell/histiocytoid carcinomas of the eyelid are extremely rare tumors considered to originate from sweat glands. Here, we report the case of a 72-year-old man diagnosed with primary signet-ring cell/histiocytoid carcinoma of the eyelid and present immunohistochemical analyses of the eyelid apocrine gland (Moll gland) and apocrine and eccrine sweat glands of perineum and axilla. Widespread infiltration of tumor cells with signet-ring cell or histiocytoid appearance was observed in his left eyelid, orbit, and periocular lesion. Tumor cells expressed mucins and showed immunoreactivity that was similar to that of the Moll gland: MUC6 (+), GlcNAc alpha 1 -> 4Gal -> R(-), MUC2(-), MUC5AC(-), GCDFP15(+), CD15(+), S100(-), CK7(+), CK20(-), ER(+), PgR (+), HER2(-), E-cadherin(+), p63(-), PSA(-), and TTF-1(-). The tumor cells differed from those of perineal and axillary apocrine and eccrine sweat glands, which were MUC6(-). The Moll gland was ER(-) and PgR(-), whereas perineal and axillar apocrine sweat glands were ER(+) and PgR(+), and perineal and axillary eccrine sweat glands were ER(+) and PgR(-). The tumor showed characteristics similar to that of the eyelid Moll gland, which is demonstrated to be an apocrine gland with a protein expression distinct from that of other apocrine glands. MUC6 and GCDFP15 expression are useful in identifying the Moll gland immunophenotype and GCDFP15, ER and PgR expression are useful in distinguishing primary eyelid signet-ring/histocytoid carcinoma from gastrointestinal malignancies.ArticleAMERICAN JOURNAL OF DERMATOPATHOLOGY. 34(8):E139-E145 (2012)journal articl