BACKGROUND:For the replacement treatment of long-segment tracheal defects,although tissue engineering research has made some progress in recent years,it is still not perfect,and one of the biggest difficulties is that the hemodynamic reconstruction of the tracheal replacement cannot be achieved rapidly. OBJECTIVE:To preliminarily explore the potential of polycaprolactone scaffolds modified with exosome-loaded hydrogels to construct a rapidly vascularized tracheal substitute. METHODS:Exosomes were extracted from bone marrow mesenchymal stem cells of SD rats.After preparation of hyaluronic acid methacrylate solution,the exosome solution was mixed with hyaluronic acid methacrylate solution at a volume ratio of 1:1.Hyaluronic acid methacrylate hydrogels loaded with exosomes were prepared under ultraviolet irradiation for 5 minutes.The degradation of exosome-unloaded hydrogels and the controlled release of exosome-loaded hydrogels were detected.Polycaprolactone scaffolds were prepared by 3D printing.The pure hyaluronic acid methacrylate solution and the exosome-loaded hyaluronic acid methacrylate solution were respectively added to the surface of the scaffold.Hydrogel-modified scaffolds and exosome-modified scaffolds were obtained after ultraviolet irradiation.Thirty SD rats were randomly divided into three groups with 10 rats in each group and subcutaneously implanted with simple scaffolds,hydrogel-modified scaffolds and exosome-modified scaffolds,respectively.At 30 days after surgery,the scaffolds and surrounding tissues of each group were removed.Neovascularization was observed by hematoxylin-eosin staining and Masson staining and the expression of CD31 was detected by immunofluorescence. RESULTS AND CONCLUSION:(1)As time went by,the hydrogel degraded gradually,and the exosomes enclosed in the hydrogel were gradually released,which could be sustained for more than 30 days.The exosome release rate was faster than the degradation rate of the hydrogel itself,and nearly 20%of the exosomes were still not released after 30 days of soaking.(2)Under a scanning electron microscope,the surface of the simple polycaprolactone scaffold was rough.After hydrogel modification,a layer of gel was covered between the pores of the scaffold,and the scaffold surface became smooth and dense.(3)After 30 days of subcutaneous embedding,hematoxylin-eosin staining and Masson staining showed that more neovascularization was observed inside the scaffolds of the exosome-modified scaffold group compared with the hydrogel-modified scaffold group.The hydrogels on the scaffolds of the two groups were not completely degraded.Immunofluorescence staining showed that CD31 expression in the exosome-modified scaffold group was higher than that in the hydrogel-modified scaffold group(P<0.000 1).(4)These results indicate that hyaluronic acid methacrylate hydrogels can be used as controlled-release carriers for exosomes.The 3D-printed polycaprolactone scaffold modified by hyaluronic acid methacrylate hydrogel loaded with exosomes has good biocompatibility and has the potential to promote the formation of neovascularization.

ObjectiveAt present, the matching reagents of commercially available rapid DNA instruments based on microfluidics chip technology are autosome short tandem repeat (STR) individual identification reagents. The non-recombining part of the human Y chromosome is widely used in forensic DNA analysis, particularly in cases where standard autosomal DNA profile is uninformative. Y-STR loci are useful markers to identify males and male lineages in forensic practice. In order to achieve rapid and fully integrated detection ofY-STR loci, this study constructed the RTyper Y27 microfluidic chip rapid detection system and validated the performance of this system. MethodsThe system was verified and evaluated by sensitivity, success rate, typing accuracy, peak height balance, sizing precision and accuracy, mock case sample tests, mixture detection ability, and inhibition tolerance. ResultsComplete Y-STR profiles can be obtained when the template amount of DNA standard 9948 was ≥8 ng, the number of blood cards was ≥3 pieces, and the number of oral swab scrapings was≥7 times. The success rate of fully integrated detection was 91.52%, and the concordance rates was 99.74% for 165 testing samples. The success rate of 115 blood spots in these samples was 90.43%, with a typing accuracy of 99.65%, the success rate of 50 buccal swabs was 94%, with a typing accuracy of 99.92%. There was no significant difference in typing accuracy between blood spots and buccal swab samples. The peak height ratio between different fluorescence channels was 89.81%. The standard deviation of allelic ladder for 10 runs was within 0.5 bp. The size differences between allele and corresponding allele in allelic ladder was within 0.5 bp. The maximum precision CV values within and between batches were 0.48% and 0.68%, respectively, which were lower than 15%. These data indicate that the system has good accuracy and precision. The system was capable of accurately typing oral swabs, blood cards, saliva cards, cigarette butts, blood swabs and seminal stains. Complete Y-STR profiles can be obtained and distinguish at the 1∶3 ratio of minor and major contributors in artificial male DNA mixtures. Complete Y-STR genotyping can be obtained under the interference of inhibitors, such as different concentrations of humic acid (50-400 mg/L), indigotin (20-100 nmol/L) and hemoglobin (100-500 μmol/L). ConclusionIn this study, the RTyper Y27 microfluidic chip rapid amplification system is combined with the Quick TargSeq 1.0 integrated system, and the Y-STR profile can be obtained in approximately 2 h. Through a series of verification experiments, the results show that the system has good repeatability, accuracy and stability, can meet the on-site Y-STR detection requirements, and can be used in forensic practice.

Objective To evaluate the bioequivalence of metronidazole tablet and reference formulation in Chinese healthy subjects.Methods A single-dose,two-cycle,randomized,open,self-crossover trial was designed with 48 healthy subjects randomly assigned to fasting or postprandial group.For each group,a single oral dose of metronidazole tablet(200 mg)or a reference preparation(200 mg)per cycle were enrolled.The concentration of metronidazole in plasma was measured by high performance liquid chromatography tandem mass spectrometry(HPLC-MS/MS).The non-compartmental model was applied to calculate the pharmacokinetic parameters for bioequivalence analysis via SAS 9.3 software.Results The main pharmacokinetic parameters of test and reference metronidazole tablets in the fasting group were as follows,the Cmax were(4 855.00±1 383.97)and(4 799.13±1 195.32)ng·h·mL-1;the AUC0-t were(54 834.68±12 697.88)and(55 931.35±11 935.28)ng·h·mL-1;the AUC0-∞ were(56 778.09±13 937.76)and(57 922.83±13 260.54)ng·h·mL-1;the Tmax were respectively 1.17 and 1.00 h;t1/2 were(8.99±1.76)and(9.11±1.73)h,respectively.The ratio of the geometric mean and its 90％confidence intervals(CI)of Cmax,AUC0-t and AUC0-∞ were all within the equivalent interval of 80.00％-125.00％.As for postprandial conditions,the main pharmacokinetic parameters of test and reference metronidazole tablets were as follows,the Cmax were(4 057.08±655.08)and(4 044.17±773.98)ng·h·mL-1;the AUC0-t were(55 956.42±12 228.12)and(55 121.04±11 784.55)ng·h·mL-1;the AUC0-∞ were(58 212.83±13 820.00)and(57 350.38±13 229.46)ng·h·mL-1;the Tmax were 2.50 and 2.25 h;the t1/2 were(9.37±1.68)and(9.37±1.79)h,respectively.The ratio of the geometric mean and 90％CI of Cmax,AUC0-t and AUC0-∞ were all within the equivalent interval of 80.00％-125.00％.Conclusion The two preparations were bioequivalent to Chinese healthy adult volunteers under both fasting and fed conditions.

Objective To design a wearable cardiopulmonary monitoring system and validate its performance through preliminary human trials.Methods The wearable cardiopulmonary monitoring system was composed of a data collector,a wearing vest and an information management platform.The data collector used an EFM32GG330 SCM as the main microcon-troller unit(MCU),which included a respiratory modulation module,an ECG modulation module,a body position modulation module,a wireless communication module(involving in a Bluetooth module and a Wi-Fi module),a storage module and a power management module.The wearable vest had a cardigan-type structure,and was equipped with ECG sensors and respiratory motion sensors at its inner side.The information management platform was developed with Client/Server(C/S)architecture and Java/JavaScript.The system developed was compared with Mindray's IPM10 Patient Monitor routinely used in hospitals through preliminary human trials to verify its effectiveness in monitoring human heart rate and respiratory rate.Results The system developed could continuously monitor the human heart rate and respiratory rate for a long time,and the monitoring results had high consistency with those of Mindray's IPM10 Patient Monitor.Conclusion The system can be used for medical monitoring of cardiopulmonary indicators during training or exercise,providing accurate physiological information for health management.[Chinese Medical Equipment Journal,2024,45(4):51-55]

Objective To observe the clinical efficacy of ultra-micro acupotomology combined with high and low frequency repetitive transcranial magnetic stimulation(rTMS)in the treatment of upper limb spasm after stroke.Methods A total of 106 patients with upper limb spasm after stroke were randomly divided into observation group and control group,53 cases in each group.Both groups were treated with conventional drugs and exercise therapy.The control group was treated with high and low frequency rTMS.The observation group was treated with ultra-micro needle knife on the basis of the control group.Both groups were treated for four weeks.After two weeks and four weeks of treatment,the clinical efficacy of the two groups was evaluated respectively.The changes of modified Ashworth scale(MAS)score and upper limb Fugl-Meyer scale score were observed before and after treatment in the two groups.The changes of Berg Balance Scale(BBS)score and modified Barthel Index(BI)score were compared before and after treatment between the two groups.The safety and adverse reactions of the two groups were evaluated.Results(1)After two weeks of treatment,the total effective rate was 81.13％(43/53)in the observation group and 62.26％(33/53)in the control group.The curative effect of the observation group was superior to that of the control group,and the difference was statistically significant(P＜0.05).(2)After four weeks of treatment,the total effective rate was 90.57％(48/53)in the observation group and 73.58％(39/53)in the control group.The curative effect of the observation group was superior to that of the control group,and the difference was statistically significant(P＜0.05).(3)After two and four weeks of treatment,the MAS score and upper limb Fugl-Meyer score of the observation group were significantly improved(P＜0.05),and the observation group was significantly superior to the control group in improving the MAS score and upper limb Fugl-Meyer score,the differences were statistically significant(P＜0.05).(4)After two and four weeks of treatment,the BBS score and modified BI Score of the observation group were significantly improved(P＜0.05),and the improvement of BBS score and modified BI score in the observation group was significantly superior to that in the control group,the differences were statistically significant(P＜0.05).(5)There was no significant difference in the incidence of adverse reactions between the observation group and the control group(P＞0.05).Conclusion Ultra-micro acupotomology combined with high and low frequency rTMS in the treatment of upper limb spasm after stroke can significantly improve the clinical symptoms of patients,improve the muscle strength of the upper limbs of patients,the movement and balance ability of the upper limbs,and improve the daily living ability of patients,there being remarkable curative effect.

Objective:To summarize the clinical characteristics,therapeutic effect and prognostic factors of patients with Hodgkin's lymphoma(HL).Methods:A total of 129 patients with HL diagnosed in Peking University Third Hospital from January 2010 to March 2021 who were given at least one efficacy assessment after treatment were enrolled,and their clinical data,including sex,age,pathological type,Ann Arbor stage,ECOG score,blood test,β2-microglobulin,lactate dehydrogenase level,albumin level were collected.The clinical characteristics,therapeutic effect and long-term prognosis of the patients were summarized and analyzed.Results:In classical HL,nodular sclerosis HL accounted for the highest proportion of 51.6％,followed by mixed cellularity HL(36.5％),lymphocyte-rich classical HL(3.2％),and lymphocyte depletion HL(0.7％),while nodular lymphocyte predominant HL accounted for 4.8％.The 3-year overall survival(OS)rate of HL patients was 89.8％,and 5-year OS was 85.0％.The 3-year progression-free survival(PFS)rate was 73.4％,and 5-year PFS was 63.1％.Multivariate regression analysis indicated that IPI score was an independent negative factor,while hemoglobin(Hb)level was an independent positive factor for OS in HL patients.When the mediastinal mass size was 9.2 cm,it was most significant to judge the survival status of HL patients.5-year OS and 5-year PFS were 97.4％and 76.0％in early-stage HL patients without large mass,respectively,while in patients with advanced-stage HL was 83.4％and 55.9％(both P＜0.05).After 2-4 courses of treatment,the overall response rate(ORR)of patients who received chemotherapy combined with radiotherapy was 95.0％,while that was 89.6％in those with chemotherapy alone.Conclusions:The overall prognosis of patients with HL is satisfactory,especially those in early-stage without large mass.IPI score and Hb level are independent risk factors for the prognosis of HL patients.A 9.2 cm mediastinal mass can be used as the cut-off value for the prognosis of Chinese HL patients.

Aim To explore anti-inflammatory mecha-nism of urolithin A(Uro A)based on the miRNA155-5p-regulated MAPK/NF-κB pathway in a lipopolysac-charide(LPS)-stimulated RAW264.7 inflammatory cell model.Methods The mRNA expression of miR-15-5p,p38 MAPK,JNK and ERK was detected by transfection of overexpression of miR-155-5p-mimics and miR-NC into LPS-induced RAW264.7 cells,and the miR-15-5p,p38 MAPK,JNK,and ERK mRNA expressions in the cells were detected by RT-qPCR.The effect of Uro A on cell viability was detected by MTT assay.The NO content in cell supernatant was detected by Griess assay.The cell supernatant PGE2,IL-6,IL-1 β and TNF-α expression levels were detec-ted by ELISA.The iNOS,COX-2,TLR4,and the MAPK/NF-κB pathway-related protein expression lev-els were detected by Western blot.Results The p38 MAPK,JNK and ERK mRNA expression levels were significantly higher in the miRNA155-5p overexpres-sion group than those in the miR-NC group(P＜0.01).Compared with the model group,Uro A signif-icantly inhibited miRNA155-5p,NO,PGE2,TNF-α,IL-1β,and IL-6 levels(P＜0.01)as well as de-creased the expression levels of iNOS and COX-2 pro-teins(P＜0.01)in a concentration-dependent man-ner.Moreover,Uro A could significantly inhibit the expression levels of TLR4 protein and the expression levels of phosphorylation levels of p38 MAPK,JNK,NF-κB p65,and IκBα proteins in LPS irritated RAW264.7 cells(P＜0.05).However,Uro A did not show a significant inhibitory effect on ERK1/2 pro-tein phosphorylation.Conclusion Uro A could signif-icantly inhibit LPS-induced inflammatory response,and its mechanism may be related to miRNA155-5p-mediated TLR4/MAPK/NF-κB signaling pathway.

Objective To investigate the activated phenotype and the expression of the receptor of advanced glycation endproducts(RAGE)of astrocytes after hypoxic-ischemic brain damage(HIBD)in neonatal rats and the effects of gastrodin(GAS)intervention on them.Methods Totally 48 neonatal 3 days SD rats were used to construct HIBD model and randomly divided into sham group,HIBD group and HIBD+GAS group(100 mg/kg),and the expressions of Al type astrocyte marker C3,A2 type astrocyte marker S100A10,RAGE,tumor necrosis factor-α(TNF-α),brain-derived neurotrophic factor(BDNF),and insulin-like growth factor(IGF-1)in the corpus callosum of the ischemic side were detected by Western blotting and immunohistochemical staining on day 1 and day 3 after HIBD.TNC-1 cells were divided into control group,oxygen glucose deprivation(OGD)group,OGD+GAS(0.34 mmol/L)group and GAS group,and then the protein expressions of RAGE,TNF-α,BDNF and IGF-1 were detected by Western blotting and immunofluorescence.Results In vivo,Western blotting showed that compared with the sham group,the protein expression levels of C3,S100A10,RAGE,TNF-α and IGF-1 in the 1 day and 3 days groups after HIBD group in 1 day group were significantly higher than those in the sham group(P＜0.05),but the protein expression level of BDNF decreased in 1 day group and increased in 3 days group(P＜0.05).Compared with the HIBD group,the C3,RAGE and TNF-α protein expression levels were significantly attenuated in the HIBD+GAS group(P＜0.05),and the protein expression levels of BDNF and IGF-1 further increased(P＜0.05).The protein expression of S100A10 in the 3 days group was higher than that in the HIBD group after GAS treatment(P＜0.05).The immunohistochemical staining results of C3,S100A10,and RAGE in the 1 day and 3 days groups after HIBD were consistent with Western blotting results.Furthermore,the protein expressions of RAGE and TNF-α were significantly enhanced in OGD-stimulated astrocytes(P＜0.05).After GAS intervention,while the expressions of both RAGE and TNF-α decreased significantly(P＜0.05),the expressions of BDNF and IGF-1 increased significantly(P＜0.05).Conclusion With inhibiting the up-regulation of RAGE signal in astrocyte after HIBD and expressions of A1 astrocyte and neuroinflammatory factors,gastrodin can promot the expressions of A2 astrocyte and nutritional factors,which play an important role in neuro-protective effect.

With continuous developments of regenerative medicine, mesenchymal stem cell-derived exosome (MSC-Exo) has attracted a growing attention of researchers with their inherent advantages of promoting tissue regeneration, an excellent biocompatibility and a great ease of penetration into tissues. Its specific mechanism has become a research hotspot. In cardiothoracic surgery, the role of MSC-Exo has been gradually examined. Currently the relevant studies have been conducted in the fields of cardiology, ung disease, lung transplant, tracheal transplantation and esophageal repair. The latest researches on MSC-Exo in the field of cardiothoracic surgery as well as its mechanism and outcomes were systematically summarized to provide references for more related researches in the future.

Currently three dimensional bio-printing technology has become one of the hot topics for tissue engineering tracheal grafting.Different biomaterials have their own performance advantages in the preparation and regeneration of tracheal scaffolds.It is particularly imperative to seek natural or polymeric materials with excellent profiles of printability, structural stability and biocompatibility to enable neo-cartilage formation, neo-epithelialization and neo-vascularization of tissue engineering trachea grafting.This review summarized the shortcomings and challenges of classifying and applying materials for three dimensional bio-printing tissue engineering trachea, aiming to provide new rationales for researches and applications of tissue engineering tracheal grafting.