Oral administration of TRPV4 inhibitor improves atrial calcium handling abnormalities in sterile pericarditis rats / 生理学报

Atrial Ca2+ handling abnormalities, mainly involving the dysfunction of ryanodine receptor (RyR) and sarcoplasmic reticulum Ca2+-ATPase (SERCA), play a role in the pathogenesis of atrial fibrillation (AF). Previously, we found that the expression and function of transient receptor potential vanilloid subtype 4 (TRPV4) are upregulated in a sterile pericarditis (SP) rat model of AF, and oral administration of TRPV4 inhibitor GSK2193874 alleviates AF in this animal model. The aim of this study was to investigate whether oral administration of GSK2193874 could alleviate atrial Ca2+ handling abnormalities in SP rats. A SP rat model of AF was established by daubing sterile talcum powder on both atria of Sprague-Dawley (SD) rats after a pericardiotomy, to simulate the pathogenesis of postoperative atrial fibrillation (POAF). On the 3rd postoperative day, Ca2+ signals of atria were collected in isolated perfused hearts by optical mapping. Ca2+ transient duration (CaD), alternan, and the recovery properties of Ca2+ transient (CaT) were quantified and analyzed. GSK2193874 treatment reversed the abnormal prolongation of time to peak (determined mainly by RyR activity) and CaD (determined mainly by SERCA activity), as well as the regional heterogeneity of CaD in SP rats. Furthermore, GSK2193874 treatment relieved alternan in SP rats, and reduced its incidence of discordant alternan (DIS-ALT). More importantly, GSK2193874 treatment prevented the reduction of the S2/S1 CaT ratio (determined mainly by RyR refractoriness) in SP rats, and decreased its regional heterogeneity. Taken together, oral administration of TRPV4 inhibitor alleviates Ca2+ handling abnormalities in SP rats primarily by blocking the TRPV4-Ca2+-RyR pathway, and thus exerts therapeutic effect on POAF.

Limited external fixation of plastic cardboard for the treatment of senile comminuted humeral fracture / 中国骨伤

OBJECTIVE@#To explore clinical efficacy of limited external fixation with plastic paperboard in treating senile proximal comminuted humeral fracture.@*METHODS@#From June 2015 to December 2017, 32 senile patients with proximal comminuted fracture of humerus were treated with plasticized cardboard after manual external fixation. Among them, including 13 males and 19 females aged from 55 to 85 years old with an average of(68.22±8.36) years old; 18 patients on the left side and 14 patients on the right side; all patients were regularly review shoulder X-rays and performed appropriate functional exercises. Constant-Murley shoulder joint scoring was used to evaluate clinical effects.@*RESULTS@#Thirty-two patients were followed up for 3 to 12 months with an average of (4.97±2.39) months. All patients were underwent functional exercise under guidance of physicians. Nine patients were treated with topical Chinese herbal moist heat compresses to promote shoulder function recovery. Thirty-one patients were obtained fracture healing, the time ranged from 5 to 12 weeks with an average of(7.44±1.72)weeks. One patient was not healed due to comminuted fracture of fracture end and the separation was large, the blood supply to humeral head was insufficient for necrosis absorption. Postoperative Constant-Murley shoulder score at 3 months was 87.56±6.93; 15 patients got excellent results, 14 good, 2 fair and 1 poor.@*CONCLUSIONS@#Limited external fixation with plastic paperboard for the treatment of senile proximal comminuted humeral fracture could ensure biomechanical stability of fracture, promote early recovery of shoulder joint function and shorten recovery time.