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Abstract Background Cord Blood (CB) has been considered a promising source of natural killer (NK) cells for cellular immunotherapy. However, it is difficult to expand the large numbers of highly pure NK cells from CB without cell sorting and feeder cells/multiple cytokines. In this study, we try to develop a simple, safe and economical method for ex vivo expansion and purification of NK cells from CB without cell sorting and feeder cells/multiple cytokines. Results The large numbers (mean: 1.59 × 1010) of highly pure (≥90%) NK cells from CB could be obtained through interleukin-2, group A streptococcus and zoledronate stimulation of mononuclear cells using the 21-day culture approach. When compared to resting NK cells, expanded NK cells were a higher expression of activating receptors CD16, NKG2D, NKp30, NKp44, NKp46 and activating markers CD62L and CD69, while the inhibitory receptors, CD158a and CD158b remained largely unchanged. In addition, these cells showed a higher concentration of IFN-γ, TNF-α and GM-CSF secretion and cytotoxicity to K562 cells and acute myeloid leukemia targets than resting NK cells. Conclusion We develop a simple, safe and economical method to obtain high yield, purity, and functionality NK cells from CB without cell sorting and feeder cells/multiple cytokines.

To observe the surgical procedure and outcome of percutaneous endoscopic lumbar discectomy for L5/S1 lumbar disc herniation (LDH) by the interlaminar and transforaminal approach. A total of 153 patients with L5/S1 LDH who were treated using percutaneous endoscopic transforaminal discectomy (PETD, n = 84) or percutaneous endoscopic interlaminar discectomy (PEID, n = 69) from January 2016 to January 2018 were enrolled in this retrospective study. The time of puncture, operation under the endoscope, total operation and number of fluoroscopy of the two groups were compared. All groups were followed up for two years by using the Oswestry disability index (ODI) and the Visual Analogue Scale (VAS). Additionally, the incidence of complications, reoperation and postoperative low back pain were compared between the two groups. There were no significant difference in general information between the two groups. Compared to the PEID group, the PETD group had a decreased operation time under the endoscope and an increased puncture time, total operation time, and the number of fluoroscopy (p < 0.05). The preoperative VAS and ODI scores of the PETD and PEID group were decreased at the last follow-up (p < 0.05). There were no difference in the preoperative or last follow-up VAS and ODI scores, as well as complications, reoperation between the two groups (p > 0.05). The incidence of postoperative low back pain in the PETD group was lower than that in the PEID group (p > 0.05). The two-year clinical outcome of PETD is equal to that of PEID for L5/S1 LDH. Compared to those with PETD, the puncture time, total operation time and radiation exposure are lower with PEID, but the incidence of postoperative low back pain is higher. [ABSTRACT FROM AUTHOR]