Publications by authors named "Shintaro Okumura"

Article Synopsis
  • The study focuses on remnant gastric cancer (RGC) which is rare, examining clinical findings, postoperative data, and challenges in its management among 313 patients from 17 Japanese institutions.
  • Results show that a significant portion of patients had early-stage RGC, but disease recurrence rates were notable, especially within the first few years post-surgery, with peritoneal recurrence being the most common.
  • Adjuvant chemotherapy (AC) appeared to improve recurrence-free survival significantly, suggesting that AC might offer similar benefits as in primary gastric cancer despite some limitations in the study design.
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Low-grade appendiceal mucinous neoplasm (LAMN) is principally characterized by low-grade cytology without evidence of invasion to other organs. We report a LAMN surgical case whose appendiceal tumor penetrated the sigmoid colon wall. An 87-year-old man was referred for endoscopic resection (ER) of a colon polyp.

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Article Synopsis
  • - The narrative review examines how social media (SoMe) is used for research communication in surgery, highlighting its role in sharing articles and enhancing citation metrics through strategies like visual abstracts.
  • - SoMe is beneficial for surgical education, allowing for the wide sharing of online training videos, though it raises concerns about varying content quality.
  • - Additionally, SoMe enables focused discussions and is increasingly used by general surgery residency programs in the U.S. for recruitment, emphasizing the importance for surgeons to understand its effective use.
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A novel diazabenzacenaphthenium photocatalyst, , with high photoredox abilities and visible-light absorption was designed and prepared in one step. Under visible-light irradiation, promoted the four-electron reduction of esters in the presence of ammonium oxalate as a "traceless reductant" to generate carbinol anion intermediates that underwent protonation with water to give the corresponding alcohols. The resulting carbinol anions also exhibited nucleophilic reactivity under the photocatalytic conditions to undergo a 1,2-addition to a second carbonyl compound, affording unsymmetric 1,2-diols.

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Background: Esophageal diverticulum is commonly associated with esophageal motility disorders, which can be diagnosed using high-resolution manometry (HRM) according to the Chicago classification. Although midesophageal diverticulum (M-ED) is associated with inflammatory processes, esophageal motility disorders have been recently identified as an etiology of M-ED.

Case Presentation: We present the case of a patient with M-ED and elevated intrabolus pressure (IBP), which did not meet the criteria for esophageal motility disorders according to the Chicago classification.

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Background: Even in cancer of unknown primary (CUP), which is rare clinical condition, solitary anterosuperior lymph node (LN) along the common hepatic artery (No.8a LN) enlargement diagnosed as metastatic adenocarcinoma has never been reported.

Case Presentation: A 68-year-old Japanese male, with a history of early gastric cancer that had been completely treated by endoscopic submucosal dissection 26 years ago, was detected a single enlarged nodule along the common hepatic artery, No.

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Background: Liver injury associated with oxaliplatin (L-OHP)-based chemotherapy can significantly impact the treatment outcomes of patients with colorectal cancer liver metastases, especially when combined with surgery. To date, no definitive biomarker that can predict the risk of liver injury has been identified. This study aimed to investigate whether organoids can be used as tools to predict the risk of liver injury.

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Background: The treatment strategy for locally advanced rectal cancer (LARC) has recently expanded from total mesorectal excision to additional neoadjuvant chemoradiotherapy (nCRT) and/or systemic chemotherapy (NAC). Data on disease recurrence after each treatment strategy are limited.

Methods: Clinical stage II to III rectal cancer patients who underwent curative surgery between July 2005 and February 2021 were analyzed.

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An umpoled electrophilic 1,4-addition to enones was achieved under photocatalytic conditions. Various enones reacted with CO in the presence of an iridium photocatalyst and a benzimidazoline reductant under blue-light irradiation to give the corresponding γ-keto carboxylic acids. Aldehydes also coupled with enones under similar photocatalytic conditions to afford γ-keto alcohols (homoaldols) that were transformed into dihydrofurans and tetrahydrofurans through azeotropic posttreatments.

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Cross-pinacol coupling of two different carbonyl compounds was achieved through successive one-electron transfer processes under photocatalytic conditions. In the reaction, an umpoled anionic carbinol synthon was generated in situ to react nucleophilically with a second electrophilic carbonyl compound. It was revealed that a CO additive promoted the photocatalytic generation of the carbinol synthon to suppress undesired radical dimerization.

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Article Synopsis
  • A 47-year-old man had surgery for rectal cancer and was monitored for 5 years without any signs of metastasis.
  • After 24 years, he developed a benign-appearing implantation cyst at the surgery site, which later transformed into mucinous adenocarcinoma.
  • The patient underwent a complex surgical procedure after receiving chemoradiotherapy, highlighting the need for medical professionals to be vigilant about potential malignant changes in implantation cysts.
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Accumulating evidence indicates that alterations of gut microbiota are associated with colorectal cancer (CRC). Therefore, the use of gut microbiota for the diagnosis of CRC has received attention. Recently, several studies have been conducted to detect the differences in the gut microbiota between healthy individuals and CRC patients using machine learning-based gut bacterial DNA meta-sequencing analysis, and to use this information for the development of CRC diagnostic model.

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Article Synopsis
  • Post-acute COVID-19 syndrome is characterized by persistent inflammation even after the SARS-CoV-2 virus is no longer detectable, though the specific mechanisms driving this condition are still not fully understood.
  • Research indicates that cells infected with SARS-CoV-2 can induce a senescence-like state in neighboring uninfected cells, leading to the production of inflammatory factors called senescence-associated secretory phenotypes (SASPs) that persist over time.
  • Experiments in human cells and mice show that these senescent cells remain active long after infection, which may contribute to ongoing inflammation in individuals with severe post-acute COVID-19 syndrome, and treatment with senolytic drugs can help reduce these effects.
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Emerging evidence is revealing that alterations in gut microbiota are associated with colorectal cancer (CRC). However, very little is currently known about whether and how gut microbiota alterations are causally associated with CRC development. Here we show that 12 faecal bacterial taxa are enriched in CRC patients in two independent cohort studies.

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We have developed a new photocatalytic umpolung reaction of carbonyl compounds to generate anionic carbinol synthons. Aromatic aldehydes or ketones reacted with carbon dioxide in the presence of an iridium photocatalyst and 1,3-dimethyl-2-phenyl-2,3-dihydro-1-benzimidazole (DMBI) as a reductant under visible-light irradiation to furnish the corresponding α-hydroxycarboxylic acids through nucleophilic addition of the resulting carbinol anions to electrophilic carbon dioxide.

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Introduction: Appropriate dissection of the infrapyloric lymph nodes (no. 6 LNs) is important in gastric cancer surgery. In laparoscopic surgery, dissection of the no.

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A convenient method for the synthesis of 1,3-dienes from readily available compounds is reported. 2-Aryoxy-1,3-dienes are produced stereoselectively by a nickel-catalyzed reaction of propargyl carbonates with phenols. Functional group tolerance is broad to allow iodo, formyl, and boryl groups.

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An electronically neutral 2-arylsilacyclobutane generates a nucleophilic carbanion at room temperature through cleavage of the benzylic C-Si bond when simply dissolved in polar aprotic solvents such as N,N-dimethylformamide (DMF). The nucleophilic species is capable of capturing carbon dioxide to furnish a silalactone. The carboxylation reaction is unique in that no additional activating agents are required.

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Purpose: We evaluate surgical outcomes of intracorporeal esophagojejunostomy in laparoscopic total gastrectomy using 2 linear stapler methods.

Materials And Methods: The functional end-to-end anastomosis (FEEA) method was chosen as a first choice. The overlap method was chosen in cases with esophageal invasion.

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A palladium-isocyanide complex opens the two four-membered rings of benzocyclobutenone and silacyclobutane to merge them into an eight-membered ring skeleton. The present reaction provides a unique example of an intermolecular cross metathesis-type reaction between covalent σ-bonds of low polarity.

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Background: Wedge resection is the most commonly used method in laparoscopic partial gastrectomy for gastric gastrointestinal stromal tumor (GIST). However, this method can involve inadvertent resection of additional gastric tissue and cause gastric deformation. To minimize the volume of resected gastric tissue, we have developed a laparoscopic partial gastrectomy with seromyotomy which we call the 'lift-and-cut method' for gastric GIST.

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The use of a quenching gas, isobutene, with a low vapor pressure was investigated to enhance the utility of hyperpolarized (129) Xe (HP Xe) MRI. Xenon mixed with isobutene was hyperpolarized using a home-built apparatus for continuously producing HP Xe. The isobutene was then readily liquefied and separated almost totally by continuous condensation at about 173 K, because the vapor pressure of isobutene (0.

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The feasibility of ventilation imaging with hyperpolarized (HP) (129) Xe MRI has been investigated for quantitative and regional assessment of ventilation in spontaneously breathing mice. The multiple breath ventilation imaging technique was modified to the protocol of spontaneous inhalation of HP (129) Xe delivered continuously from a (129) Xe polarizer. A series of (129) Xe ventilation images was obtained by varying the number of breaths before the (129) Xe lung imaging.

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