Extracorporeal membrane oxygenation for coronavirus disease 2019-associated acute respiratory distress syndrome: Report of two cases and review of the literature.

BACKGROUND: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2, is a worldwide pandemic. Some COVID-19 patients develop severe acute respiratory distress syndrome and progress to respiratory failure. In such cases, extracorporeal membrane oxygenation (ECMO) treatment is a necessary life-saving procedure. CASE SUMMARY: Two special COVID-19 cases-one full-term pregnant woman and one elderly (72-year-old) man-were treated by veno-venous (VV)-ECMO in the Second People's Hospital of Zhongshan, Zhongshan City, Guangdong Province, China. Both patients had developed refractory hypoxemia shortly after hospital admission, despite conventional support, and were therefore managed by VV-ECMO. Although both experienced multiple ECMO-related complications on top of the COVID-19 disease, their conditions improved gradually. Both patients were weaned successfully from the ECMO therapy. At the time of writing of this report, the woman has recovered completely and been discharged from hospital to home; the man remains on mechanical ventilation, due to respiratory muscle weakness and suspected lung fibrosis. As ECMO itself is associated with various complications, it is very important to understand and treat these complications to achieve optimal outcome. CONCLUSION: VV-ECMO can provide sufficient gas exchange for COVID-19 patients with acute respiratory distress syndrome. However, it is crucial to understand and treat ECMO-related complications.

Intracellular catalase activity instead of glutathione level dominates the resistance of cells to reactive oxygen species.

Artesunate (ARS) induced significant reactive oxygen species (ROS) generation in HepG2, HeLa, and A549 lines. However, ARS induced ROS-dependent apoptosis in HeLa and A549 cell lines but ROS-independent apoptosis in HepG2 cells. A total of 200 µM hydrogen peroxide (H2O2) significantly induced cytotoxicity in HeLa cells, while H2O2 up to 300 µM did not induce cytotoxicity in HepG2 cells, further demonstrating the strong resistance of HepG2 cells to ROS. HeLa cells had much higher basic total glutathione (T-GSH) level than HepG2 cells, while the ratio of basic reduced glutathione (GSH)/oxidized glutathione (GSSG) in HepG2 cells was nearly twice than that in HeLa and A549 cells. Inhibition of glutathione markedly enhanced H2O2- or ARS-induced cytotoxicity in HeLa and A549 cell lines but modestly enhanced the cytotoxicity of H2O2 and even did not affect the cytotoxicity of ARS in HepG2 cells. Moreover, addition of GSH remarkably prevented H2O2- or ARS-induced cytotoxicity in HeLa and A549 cell lines, further indicating the involvement of GSH in scavenging ROS in the two cell lines. HepG2 cells exhibited higher catalase activity than HeLa cells, and inhibiting catalase activity by using 3-aminotriazole (3-AT, a specific inhibition of catalase) or catalase siRNA remarkably reduced the resistance of HepG2 cells to ROS, demonstrating the key roles of catalase for the strong resistance of HepG2 cells to ROS. Collectively, catalase activity instead of glutathione level dominates the resistance of cells to ROS.

Analysis of clinical effect of unicompartmental knee arthroplasty in treating spontaneous osteonecrosis of the knee / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the short-term clinical outcome of unicompartmental knee arthroplasty for the treatment of spontaneous osteonecrosis of the knee.</p><p><b>METHODS</b>From September 2013 to April 2014,5 patients with spontaneous osteonecrosis of the knee underwent unicompartmental knee arthroplasty, included 3 males and 2 females, aged from 65 to 80 years old with an average of 74 years. The courses of disease was from 1 to 6 years with the mean of 3 years. According to the radiographic staging criteria of Koshino, 1 case was stage II, 2 cases were stage III, 2 cases were stage IV. Clinical effects were assessed by VAS score, HSS score, and knee range of motion, tibiofemoral angle before and after operation.</p><p><b>RESULTS</b>All the patients were followed up from 6 to 7 months with an average of 6.4 months. All incisions obtained primary healing, and there were no complications such as infection, thrombosis, fracture of lower limbs. All 5 patients' pain relieved and their knee function improved significantly after operation, but knee range of motion had no obviously improved. Postoperative HSS scores, VAS scores, tibiofemoral angle were significantly improved than that of preoperative.</p><p><b>CONCLUSION</b>The short-term effect of unicompartmental knee arthroplasty in treating spontaneous osteonecrosis of the knee is satisfactory.</p>