Predictor of respiratory disturbances during gastric endoscopic submucosal dissection under deep sedation

BACKGROUND Sedation is commonly performed for the endoscopic submucosal dissection(ESD) of early gastric cancer. Severe hypoxemia occasionally occurs due to the respiratory depression during sedation.AIM To establish predictive models for respiratory depression during sedation for ESD.METHODS Thirty-five adult patients undergoing sedation using propofol and pentazocine for gastric ESDs participated in this prospective observational study. Preoperatively, a portable sleep monitor and STOP questionnaires, which are the established screening tools for sleep apnea syndrome, were utilized. Respiration during sedation was assessed by a standard polysomnography technique including the pulse oximeter, nasal pressure sensor, nasal thermistor sensor, and chest and abdominal respiratory motion sensors. The apnea-hypopnea index(AHI) was obtained using a preoperative portable sleep monitor and polysomnography during ESD. A predictive model for the AHI during sedationwas developed using either the preoperative AHI or STOP questionnaire score.RESULTS All ESDs were completed successfully and without complications. Seventeen patients(49%) had a preoperative AHI greater than 5/h. The intraoperative AHI was significantly greater than the preoperative AHI(12.8 ± 7.6 events/h vs 9.35 ± 11.0 events/h, P = 0.049). Among the potential predictive variables, age, body mass index, STOP questionnaire score, and preoperative AHI were significantly correlated with AHI during sedation. Multiple linear regression analysis determined either STOP questionnaire score or preoperative AHI as independent predictors for intraoperative AHI ≥ 30/h(area under the curve [AUC]: 0.707 and 0.833, respectively) and AHI between 15 and 30/h(AUC: 0.761 and 0.778, respectively).CONCLUSION The cost-effective STOP questionnaire shows performance for predicting abnormal breathing during sedation for ESD that was equivalent to that of preoperative portable sleep monitoring.     

Insulin‐derived amyloidosis without a palpable mass at the insulin injection site: A report of two cases

To date, almost all case reports of insulin‐derived amyloidosis described the presence of a subcutaneous mass that was observable on physical examination. This report presents two cases of insulin‐derived amyloidosis without palpable masses at insulin injection sites. In both cases, blood glucose concentrations improved, and the insulin dose could be reduced by an average of 45% after changing the insulin injection sites. The insulin absorption at the site was reduced to at most 40% of that at a normal site in one case. Magnetic resonance imaging and ultrasonography were useful to screen and differentiate insulin‐derived amyloidosis without a palpable mass. This report showed that insulin‐derived amyloidosis without a palpable mass can be present at the insulin injection site, and has similar clinical effects to insulin‐derived amyloidosis with palpable masses.     

Wnt2 accelerates cardiac myocyte differentiation from ES-cell derived mesodermal cells via non-canonical pathway

The efficient induction of cardiomyocyte differentiation from embryonic stem (ES) cells is crucial for cardiac regenerative medicine. Although Wnts play important roles in cardiac development, complex questions remain as to when, how and what types of Wnts are involved in cardiogenesis. We found that Wnt2 was strongly up-regulated during cardiomyocyte differentiation from ES cells. Therefore, we investigated when and how Wnt2 acts in cardiogenesis during ES cell differentiation. Wnt2 was strongly expressed in the early developing murine heart. We applied this embryonic Wnt2 expression pattern to ES cell differentiation, to elucidate Wnt2 function in cardiomyocyte differentiation. Wnt2 knockdown revealed that intrinsic Wnt2 was essential for efficient cardiomyocyte differentiation from ES cells. Moreover, exogenous Wnt2 increased cardiomyocyte differentiation from ES cells. Interestingly, the effects on cardiogenesis of intrinsic Wnt2 knockdown and exogenous Wnt2 addition were temporally restricted. During cardiomyocyte differentiation from ES cells, Wnt2 didn't activate canonical Wnt pathway but utilizes JNK/AP-1 pathway which is required for cardiomyocyte differentiation from ES cells. Therefore we conclude that Wnt2 plays strong positive stage-specific role in cardiogenesis through non-canonical Wnt pathway in murine ES cells.