Primary Retroperitoneal Mucinous Cystadenocarcinoma during Long-term Administration of Infliximab for the Treatment of Crohn's Disease.

We herein report a rare case of primary retroperitoneal mucinous cystadenocarcinoma (PRMC) in a 60-year-old man. The patient, who had been treated with infliximab for Crohn's disease of the colon for 13 years, was referred to our hospital for lower back pain. Contrast-enhanced computed tomography (CT) and magnetic resonance imaging revealed multiple cystic lesions in the right retroperitoneum, the calcification of the cyst, and bone lesions. Bone and CT-assisted biopsies of the retroperitoneal lesions revealed poorly differentiated adenocarcinoma. The patient was diagnosed with PRMC with bone metastases using immunohistochemical staining and positron emission tomography/CT.

Dexmedetomidine is safe and effective for reducing intraprocedural pain in colorectal endoscopic submucosal dissection.

Objectives: Endoscopic submucosal dissection (ESD) is effective for the resection of colorectal intramucosal lesions. This study was performed to examine the safety and effectiveness of using dexmedetomidine (DEX) in the anesthesia regimen of patients with colorectal lesions undergoing ESD. Methods: We retrospectively examined 287 consecutive patients who underwent ESD for colorectal lesions in our institution from January 2015 to December 2021. Outcomes including the frequency of intraprocedural pain and adverse events were compared between the DEX and no DEX groups. Moreover, univariate and multivariate analyses were conducted for each clinical factor of intraprocedural pain. Intraprocedural pain was defined as patient-reported abdominal pain or body movement during the procedure. Results: The incidence of intraprocedural pain was significantly lower in the DEX than in the no DEX group (7% vs. 17%, p = 0.02). The incidence of hypotension was also significantly higher in the DEX group (7% vs. 0%, p = 0.01), but no cerebrovascular or cardiac ischemic events occurred. In the univariate analyses, the diameter of the resected specimen, procedure time, no use of DEX, and total midazolam dose was associated with intraprocedural pain. The midazolam dose and DEX administration were significantly negatively correlated and the diameter of resected specimen and procedure time were significantly positively correlated. Multivariate logistic regression showed that no use of DEX was independently associated with intraprocedural pain (p = 0.02). Conclusions: Adding DEX to the anesthesia regimen in patients undergoing colorectal ESD appears to be safe and effective for reducing intraprocedural pain.

Longly-attached cap can contribute to en bloc underwater endoscopic mucosal resection of 20-30 mm colorectal intramucosal lesions.

Background and study aims Underwater endoscopic mucosal resection (UEMR) is effective for colorectal intramucosal lesions. The aim of this study was to evaluate whether a longly-attached cap in UEMR improves the en bloc resection rate for 20-30 mm lesions. Patients and methods We performed a retrospective study at a tertiary institute. Candidates for the study were systematically retrieved from an endoscopic and pathological database from October 2016 to December 2020. We assessed the procedural outcomes with UEMR for lesions ≥ 20 mm in size and the clinical factors contributing to en bloc resection. Results A total of 52 colorectal lesions that underwent UEMR were included. The median procedure time was 271 (66-1264) seconds. The en bloc resection rate and R0 resection rate were 75 % and 73 %, respectively. Intraprocedural perforation occurred in one (1.9 %) case, but no bleeding occurred. Delayed bleeding occurred in one (1.9%) case, but no delayed perforation occurred. Regarding tumor size, macroscopic type, tumor location, and the presence or absence of a history of abdominal operation, there was no significant difference between the en bloc resection and piecemeal resection groups. The visibility of the whole lesion, a longly-attached cap, and sessile serrated lesions were more frequently observed in the en bloc resection group than in the piecemeal resection group ( P  < 0.001, P  = 0.01, and P  = 0.04, respectively). Multivariate analysis showed that a longly-attached cap was the only independent factor associated with en bloc resection ( P  = 0.02). Conclusions A longly-attached cap might contribute to en bloc resection.

Primary Hepatic Neuroendocrine Carcinoma with Thrombocytopenia Due to Diffuse Bone Marrow and Splenic Infiltration: An Autopsy Case.

An 82-year-old man with fever and back pain was referred to our hospital and was thus found to be thrombocytopenic. A bone marrow biopsy revealed the diffuse infiltration of poorly differentiated neuroendocrine carcinoma (NEC). Computed tomography revealed a large hepatic mass. Considering the risk of bleeding due to thrombocytopenia, a needle biopsy was not performed. The patient rapidly deteriorated and died 10 days after presentation. An autopsy confirmed the diagnosis of primary hepatic NEC, with diffuse metastasis to the spleen, bone marrow, and systemic lymph nodes. This is an extremely rare case of NEC presenting with thrombocytopenia due to extensive bone marrow and splenic infiltration.

Reactivation from occult HBV carrier status is characterized by low genetic heterogeneity with the wild-type or G1896A variant prevalence.

BACKGROUND & AIMS: Individuals negative for hepatitis B surface antigen (HBsAg) but positive for antibodies to hepatitis B core antigen (anti-HBc) are at risk of hepatitis B virus (HBV) reactivation under immunosuppressive conditions. We investigated clinical features and viral genetics in patients with reactivation from occult HBV infection triggered by chemotherapy or immunosuppressive therapy. METHODS: Clinical courses of 14 individuals originally HBsAg-negative but anti-HBc-positive that experienced HBV reactivation were examined. Ultra-deep sequencing analysis of the entire HBV genome in serum was conducted. Prevalence of the G1896A variant in latently infected livers was determined among 44 healthy individuals that were HBsAg-negative but anti-HBc-positive. RESULTS: In 14 cases, HBV reactivation occurred during (n=7) and after (n=7) termination of immunosuppressive therapy. Ultra-deep sequencing revealed that the genetic heterogeneity of reactivated HBV was significantly lower in patients with reactivation from occult HBV carrier status compared with that in patients from HBsAg carrier status. The reactivated viruses in each case were almost exclusively the wild-type G1896 or G1896A variant. The G1896A variant was detected in 42.9% (6/14) of cases, including two cases with fatal liver failure. The G1896A variant was observed in the liver tissue of 11.4% (5/44) of individuals with occult HBV infection. CONCLUSIONS: Reactivation from occult HBV infection is characterized by low genetic heterogeneity, with the wild-type G1896 or G1896A variant prevalent.

Entrainment in a chemical oscillator chain with a pacemaker.

Entrainment by a pacemaker was investigated experimentally and numerically in a chain of chemical oscillators using coupled discrete Belousov-Zhabotinsky reaction oscillators. The spontaneous frequency of each oscillator depended on the concentration of catalyst ions. The coupling strengths among the nearest neighbor oscillators were controlled by changing the spacing distance (d) between beads. When the coupling strength was sufficiently strong, the pacemaker entrained other oscillators in the chain. Subsequently, the trigger waves propagating from a pacemaker were observed. The range of trigger wave propagation area, i.e., the number of entrained oscillators, depended on d. Numerical simulation for the system described the experimental results well. Furthermore, photic noise maximized the strength of entrainment at an optimal noise intensity.