Characterization of liver-cirrhosis nodules by analysis of gene-expression profiles and patterns of allelic loss

To disclose genetic mechanisms involved in development or progression of hepatocellular carcinoma (HCC), we used a genome-wide cDNA microarray consisting of 8,448 genes to compare gene-expression profiles among 12 liver-cirrhosis nodules (LCNs) and five specimens of HCC excised from a single patient and carefully prepared by laser-capture microdissection (LCM). The expression patterns enabled us to identify 72 genes that were frequently upregulated and 57 that were downregulated specifically in the LCN specimens as compared to the HCCs. We also documented upregulation of 31 genes and downregulation of seven others in both HCC and LCN tissues. Several types of intracellular kinase, including receptor-type kinase, were upregulated in LCNs. Expression patterns of HCCs and LCNs generally represented two genetically distinct groups when subjected to a hierarchical clustering analysis, although expression profiles of two of the LCNs resembled the HCC pattern. Analysis of allelic losses at microsatellite loci revealed that LCNs showed frequent loss of heterozygosity (LOH) (33%) in chromosomal regions 6q and 22q; over half of the LCNs had lost an allele for at least one of the 28 loci examined. The presence of early genetic changes among LCNs, with additional genetic changes occurring during formation of HCCs, suggests that hepatocellular carcinogenesis follows the multistep model established for colon cancers and that some LCNs may be precancerous lesions.     

Morphological evidence for neuronal regulation of luteinizing hormone-releasing hormone-containing neurons by neuropeptide Y in the rat septo-preoptic area

Using a preembedding double immunolabeling technique, synaptic contacts were found between luteinizing hormone-releasing hormone (LHRH)-containing neurons and neuropeptide Y-containing axonal fibers in the rat septo-preoptic area. In demonstrating LHRH neurons, we used mainly an antiserum generated against rat gonadotrophic hormone-releasing hormone-associated peptide. Although many diaminobenzidine-labeled neuropeptide Y-containing fibers were seen around silver-gold-labeled LHRH cell bodies, synapses with synaptic membrane specialization were scarce. The fiber terminals usually contained many small clear vesicles and some large cored vesicles. The synapses were characterized with the presynaptic accumulation of the small clear vesicles and symmetric thickenings of the synaptic membranes.     

LEIOMYOBLASTOMA OF THE GREATER OMENTUM

A case of leiomyoblastoma of the greater omentum, occurring in a 36-year-old man was described. Leiomyoblastoma of the omentum is extremely rare and only 6 cases have been reported in the Japanese and English literature up to date. According to the review of these cases, including the present case, 1) females were affected more frequently than males, and the age ranged from 36 to 76 years; 2) leiomyoblastoma was usually a large tumor which caused abdominal fullness and pain, and occasionally complicated with anemia and bloody ascites; 3) mitosis was rare, and there was no sign of metastasis and recurrence. Finally the morphological criteria and clinical parameters of malignancy in leiomyoblastoma were discussed. ACTA PATHOL. JPN. 37: 1691-1698, 1987.     

Involvement of a cis-acting element in the suppression of carbamoyl phosphate synthetase I gene expression in the liver of carnitine-deficient mice

The expression of carbamoyl phosphate synthetase I (CPS) gene is suppressed in the liver of carnitine-deficient juvenile visceral steatosis (JVS) mice at weaning and under starvation at adult age. To clarify the suppression mechanism, we produced CPSL transgenic JVS mice carrying a transgene composed of the chloramphenicol acetyltransferase (CAT) gene with the upstream region (-12 kb to +138) of the rat CPS gene and CPSE transgenic JVS mice carrying a transgene composed of the luciferase gene with minimal promoter (299 bp from -161 to +138) and enhancer (469 bp around -6.3 kb) fragments of the rat gene. The expression of the CAT gene as well as the endogenous CPS was suppressed in CPSL transgenic JVS mice, but luciferase gene expression was not suppressed in CPSE transgenic JVS mice. We isolated the 5'-upstream region of the mouse CPS gene and identified an activator protein-1 (AP-1) site downstream of the minimum enhancer region of both rat and mouse CPS genes. In conjunction with the 313-bp mouse promoter region, the 714-bp mouse enhancer fragment conferred a cell-type-dependent hormone responsiveness. In rat primary cultured hepatocytes, the addition of oleic acid suppressed reporter gene expression induced by dexamethasone in the construct containing the enhancer fragment of 714 bp with the AP-1 site, but not in its AP-1 site mutants or in 519 bp without the AP-1 site. These results strongly suggest that direct protein-protein interaction between AP-1 and glucocorticoid receptor is not involved in the suppression of the CPS gene in JVS mice and that the AP-1 element is the cis-element which is responsible for the suppression.     

A NEW STAINING METHOD FOR DEMONSTRATION OF PVP IN TISSUE SECTION

A new staining method for demonstration of PVP deposited in tissue with use of anthraquinone vat dyes (caledon blue XRN, caledon jade green, caledon gold orange) was described. Caledon blue XRN was the most suitable dye for staining of PVP, because of its specificity of staining and applicability of many counter-stainings. The probable mechanism of staining was briefly discussed comparing with that of Congo red method. ACTA PATH. JAP. 18: 345–350, 1968.     

Apatite-forming ability and mechanical properties of PTMO-modified CaO-SiO2 hybrids prepared by sol-gel processing: effect of CaO and PTMO contents

Transparent monolithics of triethoxysilane end-capped poly(tetramethylene oxide) (Si-PTMO)-modified CaO-SiO2 hybrids were successfully synthesized by hydrolysis and polycondensation of Si-PTMO, tetraethoxysilane (TEOS) and calcium nitrate. As for the samples with varying (Ca(NO3)2)/(TEOS) molar ratios under constant ratio of (Si-PTMO)/(TEOS) of 2/3 in weight. the apatite-forming ability in a simulated body fluid (SBF) which is indicative of bioactivity. remarkably increased with increasing CaO content, although the tensile strength and Young's modulus decreased. The hybrid with (Ca(NO3)2)/(TEOS) = 0.15 in mol formed an apatite on its surface within only 1 day. For this series of samples, the strain at failure which is a measure of capability for deformation of material, was found to be about 30% and almost independent of CaO content. As for the samples with varying (Si-PTMO)/(TEOS) weight ratios under constant ratio of (Ca(NO3)2)/(TEOS) of 0.15 in mol, the strain at failure increased with increasing Si-PTMO content, but the apatite-forming ability, tensile strength and Young's modulus decreased. Thus, the synthesis of the hybrids exhibiting both high apatite-forming ability and high extensibility can be achieved by selecting suitable CaO and Si-PTMO contents. These new kind of hybrid materials may be useful as bioactive bone-repairing materials.     

A novel case of a sporadic desmoid tumour with mutation of the beta catenin gene

A 42 year old man without familial adenomatous polyposis had recurrent desmoid tumours in the left subclavicular site. Histological examination showed a typical desmoid tumour. Molecular analysis was performed in genomic DNA from this tumour, using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and direct sequencing methods. No mutation could be detected in the entire coding sequence of the APC gene, nor in H-ras, K-ras, N-ras, or p53 genes. On seeking a mutation of the beta catenin gene (CTNNB1), an activating mutation from ACC (Thr) to GCC (Ala) at codon 41 was found. Immunohistochemical staining showed that accumulated beta catenin protein was predominantly localised in the nuclei of desmoid cells. This is the first example of a sporadic desmoid tumour in which a mutation of the beta catenin gene was revealed.