Takeshi Yoshida

Active oxygen species generated by monocytes and polymorphonuclear cells in Crohn's disease

Chemiluminescence (CL) analysis of monocytes and polymorphonuclear cells (PMNs) was performed on 13 patients with Crohns disease (CD) and 10 healthy volunteers. The percentages of monocyte populations in mononuclear cells obtained from the patients with CD were greater than those from the healthy volunteers, but the numbers of PMNs were not different between the two groups. The peak level of phorbol myristate acetate (PMA)-induced CL activity generated by diluted whole blood from the patients with CD was more significantly elevated than that from the healthy volunteers, whereas the peak levels of opsonized zymosan-induced CL activity did not differ between the two groups. In monocytes, the peak levels of both PMA- and opsonized zymosan-induced CL activity were significantly higher in the patients with CD than in the healthy volunteers. CL in PMNs, however, showed no significant difference between CD and controls. It is suggested that monocytes of CD have a large capacity to generate active oxygen species. The present study suggests that excessive active oxygen species released by monocytes and perhaps macrophages may play an important role in formation of the intestinal lesions in CD.

Endoscopic diagnosis of early squamous neoplasia of the esophagus with iodine staining: High-grade intra-epithelial neoplasia turns pink within a few minutes

Background and Aim:  The ability to detect early squamous neoplasia of the esophagus can be enhanced considerably by iodine staining during endoscopic examination; however, there has been no study on distinguishing high‐grade intra‐epithelial squamous neoplasia from low‐grade dysplasia by endoscopic examination. We assumed that high‐grade intra‐epithelial neoplasia could be identified as iodine‐unstained areas more distinct and reddish than low‐grade dysplasia after the brown color of iodine solution has faded, because there is almost no remaining glycogen‐containing epithelium in high‐grade intra‐epithelial neoplasia.

Clinicopathological analysis of early-stage gastric cancers detected after successful eradication of Helicobacter pylori.

Background and Aims:  The results of a randomized controlled study and meta‐analysis study have recently proved that Helicobacter pylori eradication has a preventive effect against the development of metachronous and primary gastric cancer. However, gastric cancer is sometimes detected after successful eradication. There is a lack of study about gastric cancers in eradicated patients. To clarify the characteristics of gastric cancers detected after H. pylori eradication, we analyzed the clinicopathological features of these cancers.

Endoscopic resection (endoscopic mucosal resection/ endoscopic submucosal dissection) for superficial esophageal squamous cell carcinoma: current status of various techniques.

Endoscopic resection (ER) has been widely accepted as an effective and minimally invasive treatment for patients with superficial esophageal squamous cell carcinoma (SCC). Techniques of conventional endoscopic mucosal resection (EMR) were first developed for ER. There are three representative methods of conventional EMR: endoscopic esophageal mucosal resection (EEMR)‐tube method, EMR using a cap‐fitted endoscope (EMRC) method and two‐channel EMR method. In the past decade, techniques of endoscopic submucosal dissection (ESD) have become established as standard methods of ER. ESD allows en bloc resection of a lesion, irrespective of the size and shape of the lesion. Recently, results of retrospective cohort studies confirming that ESD is superior to EMR as a curative treatment for superficial esophageal SCC have been reported. Representative knives that are now frequently used in esophageal ESD include Hook knife, Triangle tip knife, IT knife nano, Flush knife‐BT, Dual knife, SB knife, and so on. Although there are various knives developed for ESD, the basic techniques for safe and effective ESD are the same.

p53 transactivation is involved in the antiproliferative activity of the putative tumor suppressor RBM5

RBM5 (RNA‐binding motif protein 5) is a nuclear RNA binding protein containing 2 RNA recognition motifs. The RBM5 gene is located at the tumor suppressor locus 3p21.3. Deletion of this locus is the most frequent genetic alteration in lung cancer, but is also found in other human cancers. RBM5 is known to induce apoptosis and cell cycle arrest but the molecular mechanisms of RBM5 function are poorly understood. Here, we show that RBM5 is important for the activity of the tumor suppressor protein p53. Overexpression of RBM5 enhanced p53‐mediated inhibition of cell growth and colony formation. Expression of RBM5 augmented p53 transcriptional activity in reporter gene assays and resulted in increased mRNA and protein levels for endogenous p53 target genes. In contrast, shRNA‐mediated knockdown of endogenous RBM5 led to decreased p53 transcriptional activity and reduced levels of mRNA and protein for endogenous p53 target genes. RBM5 affected protein, but not mRNA, levels of endogenous p53 after DNA damage suggest that RBM5 contributes to p53 activity through post‐transcriptional mechanisms. Our results show that RBM5 contributes to p53 transcriptional activity after DNA damage and that growth suppression and apoptosis mediated by RBM5 are linked to activity of the tumor suppressor protein p53.

Heck reaction with a silica-supported Pd-TPPTS liquid phase catalyst: effects of reaction conditions and various amines on the reaction rate

Abstract Supported liquid phase catalysts (SLPC) were prepared using a porous silica, ethylene glycol (EG), and triphenylphosphine trisulfonate sodium salt (TPPTS) and used for the Heck reaction of iodobenzene (PhI) and butyl acrylate (BA) in the presence of amine. The reaction rate depends on the concentration of Pd-TPPTS complex in the supported EG phase, not on the total quantity of Pd-TPPTS. The rate increases linearly with the PhI concentration. The reaction rate also increases linearly with the concentrations of BA and triethylamine (Et 3 N) when these are low. However, a plateau and a maximum of the rate are seen with further increasing the concentrations of BA and Et 3 N, respectively. As a result of the complex of these modes of the dependence, the reaction rate increases with the total concentration of PhI, BA and Et 3 N in an order of two. The dependence of the reaction rate on those concentrations with a palladium-triphenylphosphine (Pd-TPP) homogeneous catalyst is quite similar to that with SLPC. The reaction rate depends also on the type of the amine used. Tributylamine (Bu 3 N) gives faster reaction rates than Et 3 N with both SLPC and Pd-TPP. However, such an effect of trihexylamine (Hex 3 N) is seen only with Pd-TPP. In the SLPC system, Hex 3 N gives almost the same rate as that with Et 3 N. Promotive effect of recycle use of the SLPC sample is also affected by the type of the amine.

Palladium-based supported liquid phase catalysts: influence of preparation variables on the activity and enhancement of the activity on recycling in the Heck reaction

Abstract Supported liquid phase catalysts (SLPC) were prepared using a porous silica, ethylene glycol, palladium acetate, and triphenylphosphine trisulfonate sodium salt (TPPTS). The SLPC samples prepared were used for Heck reaction of iodobenzene and butyl acrylate with triethylamine base in toluene and the influence of catalyst preparation conditions was examined. The rate of reaction depends on the concentration of palladium–TPPTS complexes in the dispersed phase of ethylene glycol but not on the quantity of the dispersed liquid used. The SLPC sample can be easily separated by simple filtration and it is recyclable; interestingly, the rate of reaction is promoted on the repeated runs, due to the formation and accumulation of Et 3 NHI adduct in the dispersed phase.

Preliminary Trial of Rebamipide for Prevention of Low-Dose Aspirin-Induced Gastric Injury in Healthy Subjects: A Randomized, Double-Blind, Placebo-Controlled, Cross-Over Study

Although low-dose aspirin is widely used, since it is a cheap and effective means of prevention of cardiovascular events, it can cause hemorrhagic gastrointestinal complications. The aim of this study was to evaluate the efficacy of rebamipide in preventing low-dose aspirin-induced gastric injury. A randomized, double-blind, placebo-controlled, crossover trial was performed in twenty healthy volunteers. Aspirin 81 mg was administered with placebo or rebamipide 300 mg three times daily for 7 consecutive days. The rebamipide group exhibited significant prevention of erythema in the antrum compared with the placebo group (p = 0.0393, respectively). Results for the body and fornix did not differ significantly between the placebo and rebamipide groups. In conclusion, short-term administration of low-dose aspirin induced slight gastric mucosal injury in the antrum, but not in the body or fornix. Rebamipide may be useful for preventing low-dose aspirin-induced gastric mucosal injury, especially which confined to the antrum.

Simultaneous application of two or more supported liquid-phase organometallic catalysts: heterogeneous multifunctional reaction systems

Abstract Using the form of supported liquid-phase catalysts, two or more homogeneous catalysts can simultaneously be used with retaining their own activities and taking the advantage of catalyst–product separation and catalyst recycling.

Clinical response is associated with elevated plasma interleukin-1 receptor antagonist during selective granulocyte and monocyte apheresis in patients with ulcerative colitis

Depletion of granulocytes and monocytes (GM) by selective apheresis (GMA) with an Adacolumn exerts an anti-inflammatory effect in patients with ulcerative colitis (UC) or rheumatoid arthritis. However, the mechanism of the anti-inflammatory effect of GMA is not fully understood yet. We investigated the effect of GMA on the plasma concentration of interleukin-1 receptor antagonist (IL-1ra), a potent anti-inflammatory cytokine. Twenty-six patients with active UC received GMA at one session per week for 5 consecutive weeks. Clinical response was defined as Δclinical activity index (ΔCAI=CAI at entry – CAI at post)≥4, while clinical remission was defined as CAI≤4. Twenty-one of twenty-six patients (80.8%) responded to GMA. In the first session, plasma from responder patients showed a significant (P < 0.01) increase in IL-1ra in the Adacolumn outflow. In contrast, there was no change in IL-1ra in nonresponders. In conclusion, release of IL-1ra during GMA might be one mechanism of clinical efficacy associated with this therapy.