Clinical associations and risk factors for bleeding from colonic angiectasia: a case-controlled study.

AIM: A case-controlled study was performed to investigate the association of colonic angiectasia with other conditions and to identify risk factors for bleeding. METHOD: Information was collected from all patients who underwent colonoscopy at our hospital between January 2008 and December 2010. Data on 90 individuals with angiectasia [58 men; median age 69 (26-92) years] were compared with those of 180 individuals without angiectasia, matched for gender and age. RESULTS: Multivariate analysis showed that occult gastrointestinal bleeding [odds ratio (OR) 2.523; 95% confidence interval (CI) 1.238-5.142], liver cirrhosis (OR 13.195; 95% CI 3.502-49.711), chronic renal failure (OR 6.796; 95% CI 1.598-28.904) and valvular heart disease (OR 6.425; 95% CI 1.028-40.165) were identified as significant predictors of the presence of colonic angiectasia. Eight patients were diagnosed with bleeding from angiectasia. Cardiovascular disease (OR 22.047; 95% CI 1.063-457.345) and multiple angiectasias (P-value 0.0019) were identified as significant risk factors for active bleeding. Medication and a large size were not associated with an increased risk of bleeding. CONCLUSION: The presence of colonic angiectasia was associated with valvular heart disease, liver cirrhosis and chronic renal failure. Valvular heart disease and multiple lesions increased the risk of bleeding.

Gastric variceal rupture successfully treated with repeated EIS and EVL.

A 68-year-old female with liver cirrhosis presented at the Emergency Room of our hospital with copious tarry stools. Upper gastrointestinal endoscopy showed an isolated gastric variceal rupture, and we performed endoscopic injection sclerotherapy using cyanoacrylate, on four occasions, resulting in successful hemostasis. Injection of CA is a useful emergency treatment option for gastric variceal bleeding without gastro-renal shunt.

Portal vein thrombosis treated using danaparoid sodium and antithrombin III.

A 45-year-old man under treatment for liver cirrhosis (LC) due to chronic hepatitis C and hemophilia A was seen in our emergency room because of a 10-kg weight gain in the previous week due to ascites. Portal vein thrombosis (PVT) was detected with computer tomography (CT) and ultrasonographic (US). Danaparoid sodium (DS) and antithrombin III (AT III) were administrated and doppler US images showed improvement of portal venous blood flow. DS or AT III may be safe and alternative therapies for PVT.

Involvement of JNK pathway in the promotion of the early stage of colorectal carcinogenesis under high-fat dietary conditions.

BACKGROUND AND AIMS: The molecular mechanisms underlying the promotion of colorectal carcinogenesis by a high-fat diet (HFD) remain unclear. We investigated the role of the insulin-signal pathway and the c-Jun N-terminal kinase (JNK) pathway, which reportedly play crucial roles in insulin resistance, during colorectal carcinogenesis in the presence of hyperinsulinaemia induced by a HFD. METHODS: Azoxymethane-induced aberrant crypt foci formation and cell proliferation in the colonic epithelium were compared between mice fed a normal diet (ND) and mice fed a HFD. A western blot analysis was performed to elucidate the mechanism affecting colorectal carcinogenesis by a HFD. RESULTS: The number of aberrant crypt foci and the colonic epithelial cell proliferative activity were significantly higher in the HFD group than in the ND group. While the plasma insulin level was significantly higher in the HFD group than in the ND group, a western blot analysis revealed the inactivation of Akt, which is located downstream of the insulin receptor, in the colonic epithelia of the HFD group. On the other hand, JNK activity was significantly higher in the HFD group than in the ND group. A JNK specific inhibitor significantly suppressed the increase in epithelial cell proliferation only under a HFD, but not under a ND. CONCLUSIONS: Colonic cell proliferation was promoted via the JNK pathway in the presence of a HFD but not in the presence of a ND. This novel mechanism may explain the involvement of the JNK pathway in the effect of dietary fat intake on colon carcinogenesis.

Aperitif effects on gastric emptying: a crossover study using continuous real-time 13C breath test (BreathID System).

The aim of this study was to determine whether there is a correlation between aperitif and gastric emptying. Ten healthy male volunteers participated in this randomized, two-way crossover study. Under two conditions (after drinking an aperitif versus not), the (13)C breath test was performed for 4 h with a liquid meal (200 kcal/200 ml) containing 100 mg (13)C acetate. We used 50 ml of umeshu as the aperitif. This is a traditional Japanese plum liqueur, and contains 7 ml alcohol (14%). In the aperitif group, T(1/2), T(lag), and T(peak) were significantly delayed [T(1/2) (132: 113-174) versus (112: 92-134) (P = 0.0069); T(lag) (80: 63-94) versus (55: 47-85) (P = 0.0069); and T(peak) (81: 62-96) versus (54: 34-84) (P = 0.0069), (median: range, aperitif versus control, min)]. Gastric emptying was significantly delayed in the aperitif group as compared with the control group. This study revealed that even a small amount of alcohol such as an aperitif may contribute to delayed gastric emptying.

Characterization of dental pulp stem cells of human tooth germs.

In previous studies, human dental pulp stem cells (hDPSCs) were mainly isolated from adults. In this present study, we characterized hDPSCs isolated from an earlier developmental stage to evaluate the potential usage of these cells for tissue-regenerative therapy. hDPSCs isolated at the crown-completed stage showed a higher proliferation rate than those isolated at a later stage. When the cells from either group were cultured in medium promoting differentiation toward cells of the osteo/odontoblastic lineage, both became alkaline-phosphatase-positive, produced calcified matrix, and were also capable of forming dentin-like matrix on scaffolds in vivo. However, during long-term passage, these cells underwent a change in morphology and lost their differentiation ability. The results of a DNA array experiment showed that the expression of several genes, such as WNT16, was markedly changed with an increasing number of passages, which might have caused the loss of their characteristics as hDPSCs.

Three urocortins in medaka: identification and spatial expression in the central nervous system.

The urocortin (UCN) group of neuropeptides includes urocortin 1/sauvagine/urotensin 1 (UTS1), urocortin 2 (UCN2) and urocortin 3 (UCN3). In recent years, evidence has accumulated showing that UCNs play pivotal roles in mediating stress response and anxiety in mammals. Evidence has also emerged regarding the evolutionary conservation of UCNs in vertebrates, but very little information is available about UCNs in non-mammalian vertebrates. Indeed, at present, there are no reports of the empirical identification of ucn2 in non-mammalian vertebrates or of the distribution of ucn2 and ucn3 expression in the adult central nervous system (CNS) of these animals. To gain insight into the evolutionary nature of UCNs in vertebrates, we cloned uts1, ucn2 and ucn3 in a teleost fish, medaka and examined the spatial expression of these genes in the adult brain and spinal cord. Although all known UCN2 genes except those in rodents have been reported to likely lack the necessary structural features to produce a functional pre-pro-protein, all three UCN genes in medaka, including ucn2, displayed all of these features, suggesting their functionality. The three UCN genes exhibited distinct spatial expression patterns in the medaka brain: uts1 was primarily expressed in broad regions of the dorsal telencephalon, ucn2 was expressed in restricted regions of the thalamus and brainstem and ucn3 was expressed in discrete nuclei throughout many regions of the brain. We also found that these genes were all expressed throughout the medaka spinal cord, each with a distinct spatial pattern. Given that many of these regions have been implicated in stress responses and anxiety, the three UCNs may serve distinct physiological roles in the medaka CNS, including those involved in stress and anxiety, as shown in the mammalian CNS.

Somatic mutations of LKB1 and beta-catenin genes in gastrointestinal polyps from patients with Peutz-Jeghers syndrome.

Peutz-Jeghers syndrome (PJS) is characterized by multiple gastrointestinal hamartomatous polyps, mucocutaneous melanin deposition, and increased risk of cancer, mainly in the gastrointestinal tract. We examined mutations of the LKB1, beta-catenin, APC, K-ras, and p53 genes in 27 gastrointestinal hamartomatous polyps from 10 patients in nine PJS families. Of these hamartomatous polyps, one intestinal polyp had an adenomatous lesion, and one gastric polyp contained adenomatous and carcinomatous lesions. Germ-line mutations of the LKB1 gene were detected in six PJS families. Somatic mutations of the LKB1 gene were found in 5 polyps, whereas loss of heterozygosity (LOH) at the LKB1 locus at 19p was seen in 14 other polyps. In adenomatous lesions microdissected from hamartomatous polyps, both beta-catenin mutation and 19p LOH were detected. Furthermore, a carcinomatous lesion in a gastric hamartomatous polyp was found to contain a mutation of the p53 gene and LOH at the p53 locus in addition to LOH at the LKB1 locus and a beta-catenin mutation. K-ras mutations were detected in a few polyps, whereas no APC mutation or 5q LOH was detected in hamartomatous polyps. These results suggest that gastrointestinal hamartomatous polyps in PJS patients develop through inactivation of the LKB1 gene by germ-line mutation plus somatic mutation or LOH of the unaffected LKB1 allele, and that additional mutations of the beta-catenin gene and p53 gene convert hamartomatous polyps into adenomatous and carcinomatous lesions.

Purification and some properties of a novel racemase, which racemizes 2-oxothiazolidine-4-carboxylic acid and 5-oxoproline, from Flectobacillus sp. strain B-1.

A novel racemase active toward 2-oxothiazolidine-4-carboxylic acid was purified 310-fold with 5% recovery to near homogeneity from a crude extract of Flectobacillus sp. B-1, which had been isolated as a bacterium being able to assimilate (S)-2-oxothiazolidine-4-carboxylic acid. The molecular weight was estimated to be 92,000 by gel filtration. The purified preparation migrated as a single band of molecular weight 49,000 upon SDS-polyacrylamide gel electrophoresis. The enzyme exhibited maximum activity at pH 8.0 and 45 degrees C. The enzyme also racemized 5-oxoproline but did not act on proline and 4-hydroxyproline. The enzyme apparently had no coenzyme requirement. The enzyme activity was inhibited to 62-100% by SH-blocking reagents such as HgCl2, AgNO3, PCMB, iodoacetamide, N-ethylmaleimide and N-bromosuccinimide.

Properties of base-pairing in the stem region of hairpin antisense oligonucleotides containing 2'-methoxynucleosides.

We have designed a new type of antisense oligodeoxyribonucleotide. These oligonucleotides are able to form hairpin loop structures at the 3'-ends. The stability to nuclease degradation was observed by incubation of these hairpin oligonucleotides with snake venom phosphodiesterase, DNA polymerase, and fetal bovine serum. Of particular interest is the hairpin antisense oligonucleotide containing 2'-methoxynucleosides with base-pairing in the stem region at the 3'-end, which has increased nuclease resistance.

The stem hairpin loop structure of p2Sp1 RNA is required for RNA-cleaving activity.

We studied the hairpin-loop structure of an RNA fragment (GUUUCGUACAAAC) (R13) with the sequence corresponding to the self-cleavage domain in the precursor of an RNA molecule from bacteriophage T4-infected Escherichia coli cells (p2Sp1 RNA). In order to determine the influence of the hairpin-loop structure on these sequence-specific cleavage reactions, we have synthesized oligoribonucleotides containing hairpin-loop, double-helical stem-loop, and single-stranded RNA structures. The cleavage was affected by the hairpin-loop structure. Furthermore, the helix-stem, which retains the thermodynamically extrastable stem hairpin-loop structures, is also important for the cleavage activity. However, the thermodynamically extrastable helix-stem structure reduced the cleavage activity of the adjacent UA and CA sequences at the helix-stem site. For the cleavage reactions of the RNA cleavage products, the R6 (ACAAAC), R7 (GUUUCGU), and R9 (GUUUCGUAC) mers from the parent RNA, R13 (GUUUCGUACAAAC), a very slight amount of cleavage product (2%) from the RNA 9 was observed, but no reaction occurred for the R6 and R7. We also describe the influences of the sequences (UA and CA) on the cleavage activity.

Cleavage effect of oligoribonucleotides substituted at the cleavage sites with modified pyrimidine- and purine-nucleosides.

The precursor of an RNA molecule from T4-infected E. coli cells (p2Spl RNA) has the capacity to cleave itself at specific positions [UpA (139-140) and CpA (170-171)], within a putative loop and stem structure. This sequence-specific cleavage requires at least a monovalent cation and non-ionic detergents. In order to determine the influence of the pyrimidine and purine bases on these sequence-specific cleavage reactions, we studied the cleavage reactions of hairpin loop RNAs substituted at the cleavage sites with modified pyrimidine- and purine-nucleosides. The cleavage was affected by the 2'-hydroxyl groups and the bases of the pyrimidines, and the 6-amino group of the purine.

Site-specific cleavage of tRNA by imidazole and/or primary amine groups bound at the 5'-end of oligodeoxyribonucleotides.

Sequence specific RNA cleaving molecules were synthesized by attaching novel polyamine derivatives bearing imidazole and/or primary amine groups to the 5'-end of DNA oligonucleotides as the sequence-recognizing moieties. The actions of the molecules on a half-tRNA(Asp) were investigated. The oligonucleotides directed the nuclease activity (the imidazole and the primary amine are the catalytic groups) of the enzyme to the nucleotides directly adjacent to the complementary target sequence on the substrate RNA. The cleavage reaction shows a bell-shaped pH dependence with a maximum at pH 7.0, indicating the participation of protonated and non-protonated imidazoles residues in the process. The specificity of these hybrid enzymes can be easily altered, and they should prove to be useful tools for probing RNA structures in solution and as potential reactive groups in antisense oligonucleotide derivatives. We also describe the site-specific cleavage of tRNA(Asp) by the cleaving reagents bearing imidazole and/or primary amine groups at the 5'-end of oligodeoxyribonucleotides.

A single uridine modification at the wobble position of an artificial tRNA enhances wobbling in an Escherichia coli cell-free translation system.

5-Methoxyuridine was introduced into the first position of the anticodon of the unmodified form of tRNA(1Ser) from Escherichia coli. The codon reading efficiencies of this tRNA (tRNA(5-methoxyuridine UGA)) relative to those of the unmodified counterpart (tRNA(UGA)) were measured in a cell-free translation system. tRNA(5-methoxyuridine UGA) was more efficient than tRNA(UGA) in the reading of the UCU and UCG codons and was less efficient in the reading of the UCA codon. Thus, the single modification of U to 5-methoxyuridine can enhance the wobble readings.