Evaluation of an in vitro muscle contraction model in mouse primary cultured myotubes.

To construct an in vitro contraction model with the primary cultured myotubes, we isolated satellite cells from the mouse extensor digitorum longus. Differentiated myotubes possessed a greater number of sarcomere assemblies and higher expression levels of myosin heavy chain, cytochrome c oxidase IV, and myoglobin than in C2C12 myotubes. In agreement with these results regarding the sarcomere assemblies and protein expressions, the primary myotubes showed higher contractile activity stimulated by the electric pulses than that in the C2C12 myotubes. These data suggest that mouse primary myotubes will be a valuable research tool as an in vitro muscle contraction model.

Pheochromocytoma Multisystem Crisis Complicated by Severe Acute Pancreatitis.

A 43-year-old man developed headache, dizziness, abdominal pain, and vomiting. His blood pressure was 203/121 mmHg, heart rate 122 beats/min, body temperature 39.1°C, and respiratory rate 24/min. He had elevated levels of creatinine at 2.95 mg/dL and lipase at 1,364 U/L as well as an extremely low calcium level at 5.2 mg/dL. Hypertriglyceridemia and hyperglycemia were seen. Chest and abdominal computed tomography showed interstitial pneumonia, severe pancreatitis, and a right adrenal tumor. The patient also developed vertebral artery dissection and medullary infarction. After right adrenalectomy, the patient was diagnosed with pheochromocytoma multisystem crisis (PMC). Acute pancreatitis might augment numerous life-threatening manifestations of PMC.

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.

Visualization of dynamic change in contraction-induced lipid composition in mouse skeletal muscle by matrix-assisted laser desorption/ionization imaging mass spectrometry.

Lipids in skeletal muscle play a fundamental role both in normal muscle metabolism and in disease states. Skeletal muscle lipid accumulation is associated with several chronic metabolic disorders, including obesity, insulin resistance, and type 2 diabetes. However, it is poorly understood whether the lipid composition of skeletal muscle changes by contraction, due to the complexity of lipid molecular species. In this study, we used matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) to investigate changes in skeletal muscle lipid composition induced by contraction. We successfully observed the reduction of diacylglycerol and triacylglycerol, which are generally associated with muscle contraction. Interestingly, we found the accumulation of some saturated and mono-unsaturated fatty acids and poly-unsaturated fatty acids containing phosphatidylcholine in contracted muscles. Moreover, the distributions of several types of lipid were changed by contraction. Our results show that changes in the lipid amount, lipid composition, and energy metabolic activity can be evaluated in each local spot of cells and tissues at the same time using MALDI-IMS. In conclusion, MALDI-IMS is a powerful tool for studying lipid changes associated with contractions.

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.

Ozonesonde Quality Assurance: The JOSIE-SHADOZ (2017) Experience.

The ozonesonde is a small balloon-borne instrument that is attached to a standard radiosonde to measure profiles of ozone from the surface to 35 km with ~100-m vertical resolution. Ozonesonde data constitute a mainstay of satellite calibration and are used for climatologies and analysis of trends, especially in the lower stratosphere where satellites are most uncertain. The electrochemical-concentration cell (ECC) ozonesonde has been deployed at ~100 stations worldwide since the 1960s, with changes over time in manufacture and procedures, including details of the cell chemical solution and data processing. As a consequence, there are biases among different stations and discontinuities in profile time-series from individual site records. For 22 years the Jülich [Germany] Ozone Sonde Intercomparison Experiment (JOSIE) has periodically tested ozonesondes in a simulation chamber designated the World Calibration Centre for Ozonesondes (WCCOS) by WMO. In October-November 2017 a JOSIE campaign evaluated the sondes and procedures used in SHADOZ (Southern Hemisphere Additional Ozonesondes), a 14-station sonde network operating in the tropics and subtropics. A distinctive feature of the 2017 JOSIE was that the tests were conducted by operators from eight SHADOZ stations. Experimental protocols for the SHADOZ sonde configurations, which represent most of those in use today, are described, along with preliminary results. SHADOZ stations that follow WMO-recommended protocols record total ozone within 3% of the JOSIE reference instrument. These results and prior JOSIEs demonstrate that regular testing is essential to maintain best practices in ozonesonde operations and to ensure high-quality data for the satellite and ozone assessment communities.

Tropospheric ozone change from 1980 to 2010 dominated by equatorward redistribution of emissions.

Since 1980, anthropogenic emissions of ozone precursors have decreased in developed regions, but increased in developing regions, particularly East and South Asia, redistributing emissions equatorwards1-4. Modeling studies have shown that the tropospheric ozone burden (B O3) is much more sensitive to emission changes in the tropics and Southern Hemisphere (SH) than other regions5-9. However, the effect of the spatial redistribution of emissions has not been isolated. Here we use a global chemical transport model to consider changes in anthropogenic short-lived emissions from 1980 to 2010, and separate the influence of changes in the spatial distribution of emissions from the total emission increase, on B O3 and surface ozone. We estimate that the spatial distribution change increased B O3 by slightly more than the combined influences of changes in the global emission magnitude itself and in global methane. These results are explained by the strong convection, fast reaction rates, and strong NOx sensitivity in the tropics and subtropics. Emissions increases in Southeast, East, and South Asia may be most important for the B O3 change. The spatial distribution of emissions has a dominant effect on global tropospheric ozone, suggesting that the future ozone burden will be determined mainly by emissions from the tropics and subtropics.

Lipidomics analysis revealed the phospholipid compositional changes in muscle by chronic exercise and high-fat diet.

Although it is clear that lipids are responsible for insulin resistance, it is poorly understood what types of lipids are involved. In this study, we verified the characteristic lipid species in skeletal muscle of a chronic exercise training model and a high-fat induced-obesity model. Three different lipidomics analyses revealed phospholipid qualitative changes. As a result, linoleic acid-containing phosphatidylcholine and sphingomyelin and docosahexanoic acid-containing phosphatidylcholine were characterized as chronic exercise training-induced lipids. On the contrary, arachidonic acid-containing phosphatidylcholines, phosphatidylethanolamines, and phosphatidylinositol were characterized as high-fat diet-induced lipids. In addition, minor sphingomyelin, which has long-chain fatty acids, was identified as a high-fat diet-specific lipid. This is the first report to reveal compositional changes in phospholipid molecular species in chronic exercise and high-fat-diet-induced insulin-resistant models. Due to their influence on cell permeability and receptor stability at the cell membrane, these molecules may contribute to the mechanisms underlying insulin sensitivity and several metabolic disorders.