OBJECTIVE　To detect the trace glutaraldehyde in the fluid from venous circuit tube of hemodialysis,a HPLC assay was developed.METHODS　20 mL fluid taken from the venous circuit tube were derived with DNPH for 3 h,then filtered and injected. Chromatography was conducted on C18 column at 29℃.The mobile phase was consisted of 60% CH3N and 40% H3PO4 with the flow rate at 1 mL*min-1, and the detetion wavelength was at 365 nm.RESULTS　The concentrations of glutaraldehyde in the fluid ranged from 14.99 to 37.40 μg.mL-1.CONCLUSION　This HPLC method is simple and accurate to detect the trace glutaraldehyde remained in the fluid from venous circuit tube.

Objective:To explore the diagnostic value and problems of artificial intelligence (AI) bone marrow cell recognition technology in the detection of minimal residual disease (MRD) of leukemia.Methods:A total of 65 cases with minimal residual disease of leukemia confirmed by flow cytometry from the Hematology Medical Center of Xinqiao Hospital affiliated to the Army Medical University (AMMU) from November 1 to December 31, 2020 were collected. The bone marrow Wright′s staining smears were obtained, and all bone marrow smears were scanned and classified automatically without artificial intervention by the analysis system based on Artificial Intelligence platform (morphogo). AI-MRD was defined to positive when the proportion of primary cells was more than 3%. According to the number of AI automatic recognition cells, the cases were divided into 18 cases of less than 500 (L500), 35 cases of 500 to 1900 (between 500 and 1900, B1900), and 12 cases of more than 1900 (M1900), no overlap or omission between groups. Kappa consistency test was performed on the results of artificial intelligence test and the results of flow cytometry for minimal residual disease of leukemia (MFC-MRD) in each group. The receiver operating characteristic curve (ROC) of the artificial intelligence test results of each group of patients was drawn based on the MFC-MRD results, and the sensitivity, specificity and accuracy of the area under the curve (AUC) value and AI results were calculated.Results:After grouping according to the number of cells automatically recognized by AI, the detection results of L500 group were MFC-MRD+/AI-MRD+7 cases, MFC-MRD+/AI-MFC-2 cases, MFC-MRD-/AI-MRD+6 cases, MFC-MRD-/AI-MRD-3 cases; In B1900 group, MFC-MRD+/AI-MRD+13 cases, MFC-MRD+/AI-MFC-6 cases, MFC-MRD-/AI-MRD+6 cases, MFC-MRD-/AI-MRD-10 cases; The results of M1900 group were MFC-MRD+/AI-MRD+5 cases, MFC-MRD+/AI-MFC-0 cases, MFC-MRD-/AI-MRD+1 case, MFC-MRD-/AI-MRD-6 cases. Taking MFC-MRD as the determination standard, the sensitivity of AI-MRD detection in L500 group, B1900 group and M1900 group was 53.8%, 68.4% and 83.3%, the specificity was 60%, 62.5% and 100%, the accuracy was 55.6%, 65.7% and 91.7%, and the AUC value were 0.568 P=0.654, 0.678 P=0.069,1.000 P=0.000. Conclusions:This study preliminarily explored the diagnostic value and problems of AI bone marrow cell recognition in the detection of minimal residual disease of leukemia. It was confirmed that when 3% of the proportion of blasts in AI cell classification is set>3% as the positive threshold of AI-MRD, the consistency between AI and MFC-MRD detection increases with the increase of the number of cells recognized by AI.

Objective:To evaluate a new type of draw-bar skin stretcher in repair of full-thickness skin defects.Methods:From May 2015 to January 2019, 52 patients with full-thickness skin defects were repaired with a new type of draw-bar skin stretcher at Daping Hospital, Army Medical University. They were 40 males and 12 females, aged from 4 to 61 years (average, 37.1 years). Their skin was stretched for primary wound closure. When primary wound closure failed, skin stretching was performed again to close the wound depending on the wound condition. When the Pinch test was negative after skin stretching, the wound was sutured directly. In cases of positive Pinch test, a skin graft or flap was used to repair the remaining wound. At 12 months after surgery, scar contracture and size of skin graft or flap were observed and wound healing after skin stretching was evaluated in comparison with the original wound.Results:After skin stretching, one-stage wound closure was achieved in 36 cases and multi-stage wound closure in 8 cases; of the remaining 8 cases, 2 were repaired by skin graft and 6 by skin flap after their wounds were reduced by skin stretching. In one-stage closed wounds, infection occurred in 3 cases and marginal necrosis in 5 cases; in the wounds repaired by skin graft or flap, no infection or necrosis was observed. The 12-month follow-up for all the patients showed fine healing of all the wounds after one-stage or multi-stage closure, linear scar, absence of scar contracture, and smaller wound sizes than the original ones after skin graft or flap repair.Conclusions:Skin stretching using our new type of draw-bar skin stretcher is an effective treatment for skin wounds. It can replace traditional skin grafting and flap surgery in some cases, but its indications should be strictly followed to avoid related complications.