[Soft tissue reconstruction strategy for sacral tumor resection].

Objective: To investigate the clinical strategy and effect of soft tissue reconstruction after sacral tumor resection in different planes. Methods: The data of 27 consecutive patients who underwent primary or secondary sacral tumor resection and soft tissue reconstruction from June 2012 to June 2021 at Dongnan Hospital of Xiamen University (the 909th Hospital) were retrospectively analyzed. There were 11 males and 16 females, aged (M(IQR)) (46.2±23.6) years (range: 16 to 72 years). Sacrospinous muscle, gluteus maximus and vertical rectus abdominis muscle flap were selected for soft tissue reconstruction according to the tumor site and the size of tissue defect. the postoperative follow-up was performed. The operative methods, intraoperative conditions, complications and disease outcomes were summarized. Results: Among the 27 patients with sacral tumor, the tumor plane was located in S1 in 8 cases, S2 in 5 cases and S3 or below in 14 cases. There were 12 patients with tumor volume≤400 cm3 and 15 patients with tumor volume>400 cm3. Operation time was 100(90) minutes (range: 70 to 610 minutes), intraoperative blood loss was 800(1 600) ml (range: 400 to 6 500 ml). Soft tissue reconstruction was performed by transabdominal rectus abdominis transfer repair in 2 cases, extraperitoneal rectus abdominis transfer repair in 1 case, gluteus maximus transfer repair in 5 cases, gluteus maximus advancement repair in 13 cases, and sacrospinous muscle transfer repair in 6 cases. Postoperative complications occurred in 6 cases, including 1 case of incision infection, 4 cases of skin border necrosis, and 1 case of delayed infection due to fracture of internal fixator 3 years after operation, all of them were cured. The follow-up time was (35±21) months. Among the patients, 6 patients had recurrence, 2 patients with Ewing sarcoma died of lung metastasis 1 year after operation, 4 patients with metastatic cancer died of primary disease, and the remaining patients survived without disease. Conclusion: Choosing different soft tissue reconstruction strategies according to sacral tumor location and tissue defect size can effectively fill the dead space after sacral tumor resection, reduce postoperative complications and improve the prognosis of patients.

[Research on the effect of PD-L1 overexpression on CLL-1 CAR-T anti-acute myeloid leukemia].

Objective: To investigate the effects of programmed death receptor ligand 1(PD-L1)on CLL-1 CAR-T against acute myeloid leukemia(AML). Methods: In this experiment, the PD-L1 expression vector was constructed, and then the lentivirus vector was packaged by three-plasmid packaging system. THP-1 monoclonal cell lines stably expressing PD-L1 were set up. The CLL-1 CAR-T was developed by our team, as the effector cell for co-culture with the THP-1 or THP1-PDL1 cell lines, respectively. Then, the LDH was tested using the kit, the supernatant cytokine was detected by CBA, and the CLL-1 CAR-T cell proliferation was demonstrated by flow cytometry(FCM)with CSFE labeled. Results: ①The PD-L1 lentivirus vector was successfully constructed, and monoclonal cell lines of THP-1 with stable PD-L1 was set up and verified by FCM and PCR. ②The overexpression of PD-L1 inhibited CLL-1 CAR-T's ability to lyse THP-1 cells(E∶F ratio 10∶1); the killing efficiency of CLL-1 CAR-T on THP1-PDL1 cells was lower than that of THP-1 cells[(15.70±9.90)% vs(51.95 ± 2.52)%, P<0.05]. ③The overexpression of PD-L1 decrease the release of cytokine[THP1-PDL1 group vs THP-1 group: IFN-γ(115.66±3.13)pg/ml vs(1708.16 ± 26.76)pg/ml, P<0.05; IL-6(17.37±0.72)pg/ml vs(124.92±4.26)pg/ml, P<0.05; IL-10(5.69±0.13)pg/ml vs(124.12±3.02)pg/ml, P<0.05]. Additionally, the proliferation of CLL-1 CAR-T was also inhibited. Conclusion: Monoclonal cell lines of THP-1 with stable PD-L1 expression were successfully constructed, and the adverse effect of PD-L1 overexpression on CLL-1 CAR-T anti-AML was confirmed, which provided a theoretical basis for the regulation of CLL-1CAR-T through the PD-1/PD-L1 pathway.

[Allogeneic CAR-T for treatment of relapsed and/or refractory multiple myeloma: four cases report and literatures review].

Objective: To investigate the safety and efficacy of allogeneic CAR-T cells in the treatment of relapsed/refractory multiple myeloma (RRMM) . Methods: CAR-T cells were prepared from peripheral blood lymphocytes of HLA mismatch healthy donors. Median age was 55 (48-60) . Allogeneic cells were derived from 3 HLA haploidentical donors and 1 HLA completely mismatch unrelated donor. Four patients with RRMM were conditioned with FC regimen followed by CAR-T cell transfusion. They were infused into CART-19 (1×10(7)/kg on day 0) and (4.0-6.8) ×10(7)/kg CART-BCMA cells as split-dose infusions (40% on day 1 and 60% on day 2) . The adverse reactions and clinical efficacy were observed during follow-up after infusion, and the amplification and duration of CAR-T cells in vivo were monitored by PCR technique. Results: CAR-T cells were successfully infused in 3 of the 4 RRMM patients according to the study plan, and the infusion in one patient was delayed by 1 day due to high fever and elevated creatinine levels on day 3. The side effects included hematological and non-hematological toxicity, grade 3 hematological toxicity in 2 patients, grade 3 CRS in 1 one, grade 1 CRES in 1 one, prolonged APTT in 3 ones, tumor lysis syndrome in 1 one, mixed chimerism detected STR and clinical GVHD manifestation in 1 one. According to the efficacy criterias of IMWG, 2 patients acquired PR, 1 MR, and 1 SD respectively. Progression-free survival was 4 (3-5) weeks and overall survival was 63 (3-81) weeks. CAR T cells were amplified 2.2 (2-14) times in the patients with a median survival time of 10 (8-36) days. Conclusions: Small sample studies suggested that GVHD may be present in the treatment of RRMM with allogeneic CAR-T cells. There were early clinical transient events after transfusion. Low amplification and short duration of CAR-T cells in vivo may be the main factors affecting the efficacy.

Study of development in an experimental animal model of a pediatric physeal slide-traction plate.

BACKGROUND: To develop a physeal slide-traction plate for children can provide rigid internal fixation of a bone fracture without inhibiting epiphyseal growth. METHODS: The slide-traction plates and standard plates were designed to configure to the femoral condyle. Twelve of thirty goats were used as normal controls and the rest were implanted with plates (right femurs were fixed with standard plates, and left femurs were fixed with slide-traction plates). All goats underwent X-ray examination at 1 month, 3 months and 6 months after surgery, and femoral length were measured. Histological staining and electron microscopy were performed to evaluate the development of the epiphyseal plate at 3 and 6 months after surgery. RESULTS: Compared to the standard plate, the slide-traction plate group exhibited more normal physeal growth, histologic features, safranin O staining, and electron microscopy structural features. There were significant differences in length in the femurs of goats fixed with slide-traction plates and standard plates at 1 month, 3 months, and 6 months after surgery, respectively. There was no difference between femurs of the normal control group and the femurs fixed with the slide-traction plates. Thicker epiphyseal plates were found in the left vs. the right femurs of the group fixed with plates at 3 and 6 months after surgery. In the group fixed with plates, Safranin O staining showed that the epiphyseal plates of the left femurs had more fuscous staining than the right femurs at 3 and 6 months after surgery. Electron microscopy also showed that cells in the epiphyseal plates of the left femurs were healthier in appearance than cells from the right femurs in the group fixed with plates. CONCLUSION: The physeal slide-traction plate can slide with the growth of the physis and is suitable for fixation of fractures in this region.

A minimally invasive anterior approach to reduction and screw fixation of coronoid fractures.

We investigated a minimally invasive anterior approach to reduce and fix coronoid fractures with a screw in eight consecutive patients and evaluated seven patients at a minimum of 1 year (mean, 78 weeks; range, 61-89 weeks). It was only possible to repair seven of eight coronoid fractures. The average time to radiographic healing was 12 weeks and all healed without the screw loosening, migration or breakage. Endoscopy permitted an excellent view of coronoid fractures, allowing anatomic fixation, and as it avoided extensive soft tissue dissection, this method preserved soft tissue attachments of small coronoid fragments. This method was safe and minimally invasive.

[Local plantar rotatory flap for repairing of soft tissue defect of heel].

OBJECTIVE: Soft tissue defect of heel is not uncommon. Transplantation of free cutaneous flap and transfer of axial cutaneous flap have been used in treating such defect successfully, but both of them are somewhat complicated. Local plantar rotatory flap might show great importance in this field. METHODS: Since March 1993 to March 1998, 9 cases with soft tissue defect of heel were repaired by local plantar rotation flaps. The size of defect ranged from 2 cm x 4 cm to 6 cm x 8 cm, and it was designed superficial to plantar fascia. The flap was medially based, and nutrilized by proximal plantar subcutaneous plexus of blood supply as well as lateral and medial plantar nerve. RESULTS: Followed up 4 months to 2 years, all the flaps were survived. Sensation of the flap was preserved in 7 patients, who had normal sensation of the donated area preoperatively. The transferred flap was endurable to body bearing. CONCLUSIONS: The flap is easily prepared with reliable blood supply and sensation of the flap preserved. The method is worthy to be recommended for widely use because of its advantages over other methods.