Synthesis of poly(conjugated ester)s by ring-opening polymerization of cyclic hemiacetal ester bearing acryl skeleton

Available online 20 August 2019Ring-opening polymerization (ROP) of 2,6-dimethyl-5-methylene-1,3-dioxan-4-one (DMDO), a cyclic hemiacetal ester containing an acrylate skeleton, was investigated. Although the ROPs catalyzed by tin(II) 2-ethylhexanoate [Sn(Oct)(2)] and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) did not yield polymeric products, diphenyl phosphate (DPP) functioned a catalyst for the ROP through acyl scission accompanying with the elimination of acetaldehyde at 50 degrees C and 80 degrees C. The resulting polymer was a poly(conjugated ester) that had similar structure to the polymer of alpha-methylene-beta-butyrolactone (M beta BL), an alpha-exomethylene lactone with four-membered ring. Copolymerizations of epsilon-caprolactone and delta-valerolactone were also performed to yield the corresponding polyesters. The chemoselective main chain scission of the copolymers at the conjugated ester units were achieved by conjugate substitution reaction with benzyl mercaptan. Although the ROP of DMDO left a problem in the control of molecular weight, DMDO exhibited a potential as an easier accessible monomer alternative to M beta BL for the preparation of bio- and chemo-degradable polyesters.ArticleEUROPEAN POLYMER JOURNAL.120:109185(2019)journal articl

α-exomethylene lactone possessing acetal–ester linkage: Polymerization and postpolymerization modification for water-soluble polymer

First published: 16 October 20152,6-Dimethyl-5-methylene-1,3-dioxa-4-one (DMDO), a cyclic acrylate possessing acetal–ester linkage, was obtained as a mixture of cis- and trans-isomers (95:5) from Baylis–Hillman reaction of an aryl acrylate. The radical and anionic polymerizations of DMDO yielded the corresponding vinyl polymers without any side reactions such as cleavage of the acetal–ester linkage. The polymerization behaviors were significantly different from that of the acyclic acrylate, α-(hydroxymethyl)acrylic acid, which was expected inactive against polymerization due to the steric hindrance around the vinylidene group by the α-substituent. The acetal–ester linkage of the obtained polymer (P1) was completely cleaved via acid hydrolysis to afford a water soluble polymer, P2. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 955–961ArticleJournal of Polymer Science Part A: Polymer Chemistry. 54(7):955-961 (2016)journal articl

Adenocarcinoma in bladder diverticulum, metastatic from gastric cancer

BACKGROUND: Metastasis to the urinary bladder from gastric cancer is rare. Metastasis to a diverticulum of the bladder from gastric cancer is extremely rare. We report a case of isolated bladder metastasis from gastric cancer and invasion localized to the muscularis propria of the primary site (stomach). CASE PRESENTATION: A 90-year-old female presented with nausea and vomiting that was diagnosed as gastric cancer, the patient also had intermittent hematuria. Pelvic computed tomography identified an abnormally thickened area in the bladder wall that was diagnosed as a diverticulum of the bladder. A biopsy of the bladder wall revealed well differentiated tubular adenocarcinoma metastatic from gastric carcinoma. CONCLUSION: Almost all cases of bladder metastasis from gastric cancer had peritoneal dissemination. This particular presentation of bladder metastasis from gastric cancer, to the best of our knowledge, has not been previously reported

Nature and Clinical Outcomes of Acute Hemorrhagic Rectal Ulcer

Acute hemorrhagic rectal ulcer (AHRU) is a relatively rare disease that can lead to massive hematochezia. Although AHRU is a potentially life-threatening disease, its characteristics and clinical course are not fully understood. In this study, the clinical features were compared between AHRU and lower gastrointestinal bleeding (LGIB) from other causes (non-AHRU). Then, risk factors for all-cause in-hospital mortality in patients with AHRU were identified. A total of 387 consecutive adult patients with LGIB who were managed at two tertiary academic hospitals in Akita prefecture in Japan were retrospectively enrolled. Subjects were divided into AHRU and non-AHRU groups according to the source of bleeding. Regression analyses were used to investigate significant associations, and the results were expressed as odds ratios (ORs) and 95% confidence intervals (CIs). AHRU was found as the bleeding source in 72 (18.6%) of the patients. In comparison to non-AHRU, having AHRU was significantly associated with in-hospital onset, age > 65 years, and systolic blood pressure < 90 mmHg. The AHRU group had a significantly higher in-hospital mortality rate in comparison to the non-AHRU group (18.0% vs. 8.3, p = 0.02), and hypoalbuminemia (<2.5 g/dL) was significantly associated with in-hospital mortality in the AHRU group (OR, 4.04; 95%CI, 1.11-14.9; p = 0.03). AHRU accounts for a substantial portion (18.6%) of LGIB in our area, where the aging rate is the highest in Japan. Since AHRU is a potentially life-threatening disease that requires urgent identification and management, further studies to identify robust risk factors associated with serious clinical outcomes are required

Usefulness of the CHAMPS score for risk stratification in lower gastrointestinal bleeding

We have recently developed a simple prediction score, the CHAMPS score, to predict in-hospital mortality in patients with upper gastrointestinal bleeding. In this study, the primary outcome of this study was the usefulness of the CHAMPS score for predicting in-hospital mortality with lower gastrointestinal bleeding (LGIB). Consecutive adult patients who were hospitalized with LGIB at two tertiary academic medical centers from 2015 to 2020 were retrospectively enrolled. The performance for predicting outcomes with CHAMPS score was assessed by a receiver operating characteristic curve analysis, and compared with four existing scores. In 387 patients enrolled in this study, 39 (10.1%) of whom died during the hospitalization. The CHAMPS score showed good performance in predicting in-hospital mortality in LGIB patients with an AUC (95% confidence interval) of 0.80 (0.73-0.87), which was significantly higher in comparison to the existing scores. The risk of in-hospital mortality as predicted by the CHAMPS score was shown: low risk (score = 4), 37.1%. The CHAMPS score is useful for predicting in-hospital mortality in patients with LGIB

Red-cell aplasia due to persistent human parvovirus B19 infection three years after umbilical cord blood transplantation-a case study

　造血幹細胞移植後に生じる貧血は，骨髄の造血能低下やウイルス感染症等の様々な背景が原因となることがあり，診断が困難であることが多い．ヒトパルボウイルス B19（human parvovirus B19：PVB19）は伝染性紅斑の原因ウイルスであり，遺伝性球状赤血球症等の赤血球寿命が短縮している溶血性貧血患者では，急性赤芽球癆を呈することが知られている．PVB19は移植患者を含む免疫不全状態の患者で慢性貧血を引き起こすことがあり，腎移植患者などでの報告例は多く存在するが，臍帯血移植後における PVB19感染による後天性赤芽球癆の症例の報告はほとんどない．今回我々は，臍帯血移植が成功したのち３年を経て発症した PVB19が４か月以上持続感染している症例を経験したので報告する．　Onset of anemia after hematopoietic stem cell transplantation can be caused by various background factors such as reduced hematopoiesis of the bone marrow and viral infection. Therefore, diagnosis is often difficult. Human parvovirus B19 (PVB19) due to acquired pure red-cell aplasia is the causative virus of erythema infectiosum, and it is well known that patients with hemolytic anemia with a short erythrocyte life span such as in the case of hereditary spherocytosis present with acute red-cell aplasia. PVB19 can cause chronic anemia in immunocompromised patients, including transplantation patients, and while there are many reported cases in kidney transplant patients, etc., there are few reported cases of cord blood transplantation. Here, we report a case of onset of PVB19 that occurred three years after successful umbilical cord blood transplantation and caused persistent infection for over a period of four months

Prospective controlled study on the effects of polyethylene glycol in capsule endoscopy

AIM: To prospectively confirm whether a small amount of polyethylene glycol (PEG) ingested after swallowing endoscopy capsule improves image quality and completion rate

Esophageal Endoscopic Submucosal Dissection Assisted by an Overtube with a Traction Forceps: An Animal Study

Esophageal endoscopic submucosal dissection (ESD) is technically difficult. To make it safer, we developed a novel method using overtube with a traction forceps (OTF) for countertraction during submucosal dissection. We conducted an ex vivo animal study and compared the clinical outcomes between OTF-ESD and conventional method (C-ESD). A total of 32 esophageal ESD procedures were performed by four beginner and expert endoscopists. After circumferential mucosal incision for the target lesion, structured as the isolated pig esophagus 3 cm long, either C-ESD or OTF-ESD was randomly selected for submucosal dissection. All the ESD procedures were completed as en bloc resections, while perforation only occurred in a beginner’s C-ESD procedure. The dissection time for OTF-ESD was significantly shorter than that for C-ESD for both the beginner and expert endoscopists (22.8±8.3 min versus 7.8±4.5 min, P<0.001, and 11.3±4.4 min versus 5.9±2.5 min, P=0.01, resp.). The frequency and volume of the submucosal injections were significantly smaller for OTF-ESD than for C-ESD (1.3±0.6 times versus 2.9±1.5 times, P<0.001, and 5.3±2.8 mL versus 15.6±7.3 mL, P<0.001, resp.). Histologically, muscular injury was more common among the C-ESD procedures (80% versus 13%, P=0.009). Our results indicated that the OTF-ESD technique is useful for the safe and easy completion of esophageal ESD

Jingmen tick virus : a tick-borne virus with unique features.

非分節化ゲノムのフラビウイルスに分類されながら、分節化したウイルスゲノムを持つingmenvirusは、昆虫及び脊椎動物に感染するアルボウイルスという性質のみならず、ゲノム構造の進化と粒子の多成分性による感染という、ウイルス学上重要な問題に対しても新しい視点を与えてくれるユニークな特徴を持っている。本稿ではJingmenvirusの中でも、このウイルス発見の端緒となったJingmen tick virusを中心にウイルス学的な特徴について解説した。The discovery of Jingmenvirus, which encodes closely related flavivirus-like enzymes but possesses segmented +ssRNA genomes, sparked significant debate regarding the evolutionary pathways leading to the creation of such viruses. This review outlines the distinctive features of Jingmenviruses, with a particular focus on the Jingmen tick virus—an arbovirus transmitted by ticks, posing potential risks as a human infectious agent.departmental bulletin pape