Factors associated with failure of high-flow nasal cannula oxygen therapy in patients with severe COVID-19: a retrospective case series.

OBJECTIVE: To identify factors associated with high-flow nasal cannula (HFNC) therapy failure in patients with severe COVID-19. METHODS: We retrospectively examined clinical and laboratory data upon admission, treatments, and outcomes of patients with severe COVID-19. Sequential Organ Failure Assessment (SOFA) scores were also calculated. RESULTS: Of 54 patients with severe COVID-19, HFNC therapy was successful in 28 (51.9%) and unsuccessful in 26 (48.1%). HFNC therapy failure was more common in patients aged ≥60 years and in men. Compared with patients with successful HFNC therapy, patients with HFNC therapy failure had higher percentages of fatigue, anorexia, and cardiovascular disease; a longer time from symptom onset to diagnosis; higher SOFA scores; a higher body temperature, respiratory rate, and heart rate; more complications, including acute respiratory distress syndrome, septic shock, myocardial damage, and acute kidney injury; a higher C-reactive protein concentration, neutrophil count, and prothrombin time; and a lower arterial partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2). However, male sex, a low PaO2/FiO2, and a high SOFA score were the only independent factors significantly associated with HFNC therapy failure. CONCLUSIONS: Male sex, a low PaO2/FiO2, and a high SOFA score were independently associated with HFNC therapy failure in patients with severe COVID-19.

[Effect of Human Umbilical Cord-derived Mesenchymal Stem Cells on Proliferation and Differentiation of Leukemia Cells].

OBJECTIVE: To investigate the effect of human umbilical cord-derived mesenchymal stem cells(HUC-MSC) on the proliferation and differentiation of NB4 treated with all-trans retinoid acid (ATRA) and its underlining mechanisms . METHODS: Human umbilical cord mesenchymal stem cells were isolated from umbilical cord of newborns. Co-culture system was established by HUC-MSC and NB4 in vitro. The experiment was divided into 4 groups: NB4 group (NB4 cells alone) , NM group (NB4 cells co-cultured with HUC-MSC) , NA group (NB4 cells treated with ATRA) , NMA group (NB4 cells co-cultured with HUC-MSC and treated with ATRA) . NB4 cells were counted by a microscopy, NB4 proliferation was monitored by CCK-8 assay, NB4 differentiation was assessed by Wright ' s staining and nitroblue tetrazolium reduction test. IL-6 levels in the culture supernatant of different groups were tested by ELISA kit. Quantitative PCR was used to detect the transcription level of CDKN1A, CCND1 and Survivin. RESULTS: NB4 and HUC-MSC in the co-culturing systems were in good condition with a slight repression of NB4 proliferation by HUC-MSC. HUC-MSC could collaborate with ATRA to induce significant NB4 differentiation. Consistent with this finding, IL-6 expression levels of co-cultured groups were remarkably higher than that in any other groups or the group of HUC-MSC alone. The quantitative PCR analysis showed that the levels of CDKN1A and CCND1 mRNA expression were increased or decreased respectively in the co-cultured groups. CONCLUSION: HUC-MSC co-culture can reduce proliferation but promote the differentiation of NB4 cells, suggesting that this effect may be closely related with the secretion of IL-6 which can affect the expression of some factors in vitro.

[Effect of BD Regimen Combined with Cyclophosphamide and Pirarubicin in Treatment of Relapse/Refractory Multiple Myeloma].

OBJECTIVE: To compare the efficacy and safety of BD regimen combined with cyclophosphamide(CTX) and pirarubicin chemotherapy(P-CAD) for patients with relapse/refractory multiple myeloma(MM). METHODS: Twenty-eight cases of relapse/refractory MM were enrolled in a group of P-CAD regimen, 36 cases of relapse/retractory MM treated with BD were used as controls. The therapeutic efficacy and adverse reactions of 2 regimens for patients with relapse/retractory MM were compared and analyzed. RESULTS: The overall response rate (CR+NCR+PR+MR) of the 28 cases treated with P-CAD regimen was 85.7%, and the response rate (CR+PR) was 75.0%. The median progression-free survival time were 16.1 months, and the average survival time were 30.6 months, while the overall response rate of the 36 patients treated with BD regimen was 63.9%, and the response rate was 55.6%. The median progression-free survival time were 13.7 months, and the average survival time were 26.7 months. The adverse reactions of 2 groups included gastrointestinal reactions, peripheral neuropathy, fatigue, skin rashes, leucopenia and thrombocytopenia, and they were all well tolerated. CONCLUSION: BD regimen combined with cyclophosphamide and pirarubicin chemotherapy can improve the response rate of patients with relapse/refractory multiple myeloma, and shows the trend of prolonging PFS and survival times. Patients were well tolerated, and this regimen is a new choice in treatment of relapse/refractory MM.