Objective To identify the function and mechanism of MR1 in proliferation of BEL-7402 cells.Methods siRNA targeting MR1 and negative control siRNA were synthesized and transfected into BEL-7402 cells using Lipofectamine 2000.The silencing effect of MR1 siRNA was determined by semi-RT-PCR.SRB assay,colony formation assay and growth curve assay were used to investigate whether MR1 siRNA regulated cellular proliferation.Cell cycles were assessed by flow cytometry.G2 arrest reagent nocodazole was used to show the potential effect of MR1 siRNA on G1 arrest.The expression of Cyclin D1 was determined by Western blotting.Results(1)MR1 mRNA significantly decreased in BEL-7402 cells 24 h after MR1 siRNA transfection.(2)MR1 siRNA induced the down-regulation of cell growth.The expression of Cyclin D1 in MR1 siRNA tranfected BEL-7402 cells decreased significantly.(3)Flow cytometry results showed that MR1 siRNA markedly decreased G2 phase population with nocodazole treatment,and distinctly increased G1 phase population.Conclusion The gene MR1 is involved in the proliferation of BEL-7402 cells.MR1 siRNA causes inhibition of the proliferation of BEL-7402 cells.One of the mechanisms ofMR1 siRNA on the proliferation of BEL-7402 cells is the induction of G1 arrest.

BACKGROUND:The differentiation of mesenchymal stem cells(MSCs)is strictly regulated by both genetic and epigenetic Factors .Emerging evidences have demonstrated that microRNA also plays an important role in this process.OBJECTIVE:To explore the differential expression of microRNA-125b during neuronal dliferentiation of Flk1~+ adipose-derived MSCs(AD-MSCs).MATERIALS:The fat samples were provided bv healthy female volunteers aged 15-35 years and recruited from the Plastic Surgery Hospital affiliated to the Chinese Academy of Medical Sciences.METHODS:Adult adipose tissues were obtained from healthy voluntears with age of 15-35 years .Using adherence method,Flk1~+ MSCs were obtained and the 3~(rd) passage cells were taken in the experiment.Cultured in neuronalinduction medium.these MSC were induced to differentiate towards neuronal lineage.The expression of microRNA-125b was examined at days 0,4,8 and 12.To explore its role in neuronal differentiation,we need to change its expression.RT-PCR and Taqman real-time PCR were carried out to explore the difierentially expression of microRNA-125b during neuronal differentiation of AD-MSCs.The effect of inhibitor on the expression of microRNA-125b was detected.RESULTS AND CONCLUTION:①The Flk-1~+MSCs were successfully induced into neuronal differentiation and displayed typical morphological changes 12 days after induction:Most cells retracted their cytoplasm ,fomling spherical cell body and emitted cellular protrusions.RT-PCR and immunocytochemistry studies confirmed their phenotype with expression of known neuronal cell markers including neurofilament,glial fibrillary acidic protein.②The expression of microRNA-125b was significant up-regulated during neuronal differentiation .Results of RT-PCR and Taqman real-time PCR were concordarlce with that of microRNA chip technology.③Inhibitor could down-regulate microRNA-125b.The results implied that microRNA-125b may play an important role in neuronal differentiation.

Objective To identify the species of cultured cells and to detect inter-species cross contamination by polymerase chain reaction (PCR).Methods From references and NCBI database,we outsourced 32 pairs of species-specific primers targeted to genomic DNA of ten common species of cultured cells.Then we screened for optional primers with high specificity and high sensitivity.PCR amplification with these primers,the genomic DNAs isolated from the tested cell line and agarose gel electrophoresis of the PCR products were done.Mixed DNA of 10 species was used as positive-control template,and water as negative-control template.Results Ten pairs of species-specific and highly sensitive primers were selected.By PCR amplification with these primers and agarose gel electrophoresis,we may easily identify the origin of cell lines and find whether the tested cell lines are contaminated by cells of other species.Conclusion This PCR assay provides a simple,rapid,sensitive,and cost-effective method to identify cell species and detect interspecies cross-contamination.

Objective:To artificially design and express a recombinant protein named as ScFv-pLLO by fusing ScFv gene of Rituximab(C2B8)and dominant antigen epitopes from listeriolysin O(LLO),and studying its anti-tumor activity.Methods:VH and VL gene sequences of C2B8 against CD20 were acquired by searching United States Patent database,and ScFv sequence was constructed by linking VL and VH with a short peptide linker.Two CD4+T cell epitopes from LLO were selected and designed to splice ScFv sequence.The recombinant gene of ScFv-pLLO was cloned into prokaryotic expression vector and purified after induction.The capacity of ScFv-pLLO target-binding to B-cell lymphomas was evaluated by flow cytometry ( FCM ) and co-immunoprecipitation ( Co-IP ) .The effects of ScFv-pLLO on B-cell lymphomas proliferation and apoptosis were detected respectively.The immunogenicity of ScFv-pLLO was assessed by lymphocyte proliferation assay.Results: ScFv-pLLO was successfully expressed.It could bind to different B-cell lymphomas cell lines and obviously inhibit the growth of Raji cells as well as inducing apoptosis.Moreover,ScFv-pLLO was able to stimulate proliferation of spleen lymphocytes of immunized mice.Conclusion: The recombinant protein ScFv-pLLO can target-bind to B-cell lymphomas,and perform inhibitory effect and induce apoptosis on Raji cells that indicate ScFv-pLLO retain the capacity of ScFv derived from monoclonal antibody against CD20.Besides, ScFv-pLLO can induce immune response.This study provides a basis for further research about the role of ScFv-pLLO on simulating tumor cell antigens as well as being tumor vaccine adjuvant.

BACKGROUND:The immunomodulatory ability of bone marrow mesenchymal stem cells(BMSCs)gives it a promising future in treating graft-versus-host disease(GVHD),especially with previous success in treating patients with acute GVHD.However,there are fewer reports concerning BMSCs in treating chronic GVHD,particularly for sclerodermatous chronic graft-versus-host disease(ScGVHD).OBJECTIVE:To evaluate the efficacy and safety of treatment of BMSCs for ScGVHD,and to primarily explore the immunological mechanism of clinical efficacy.METHODS:Four ScGVHD patients at the Affiliated Hospital of Academy of Military Medicine Science,between September 2006 and August 2008,were enrolled for this trial.The median patient age was 41 years,1 female and 3 male.The patients received BMSCs infusion at a dose of(1.0～2.0)×10~7 cells every time by intrabone marrow injection from the anterosuperior iliac spine and BMSCs from the same donor for the same patient were infused more than once.Concomitant medications for ScGVHD were individualized for each patient,but all were current standard medicines and the doses were significantly tapered.RESULTS AND CONCLUTION:After BMSCs infusion,the ratio of Th1 to Th2 was dramatically overturned,with an increase of Th1 and a decrease of Th2 reaching at a new balance.Correspondingly,symptoms of all the four patients gradually improved.During the course of BMSCs treatment,the life signs and laboratory results from the recipients remained normal.By the time of this report,there has been no recurrence of leukemia in the four patients.Although this study alone cannot guarantee the application of BMSCs in ScGVHD,the results are strongly in favor of the idea that the BMSCs treatment for ScGVHD patients is therapeutically practical without any detectable side effects,which may provide a new insight into the matter of treating ScGVHD clinically,thus will greatly increase the survival rate of leukemia after allogeneic bone marrow transplantation.

Objective:To analyze the clinical characteristics of patients with Vibrio vulnificus infection, share diagnosis and treatment experience, and establish a rapid diagnosis procedure for this disease. Methods:This study was a retrospective case series study. From January 2009 to November 2022, 11 patients with Vibrio vulnificus infection who met the inclusion criteria were admitted to the Department of Burns and Wound Repair of Guangdong Provincial People's Hospital Affiliated to Southern Medical University. The gender, age, time of onset of illness, time of admission, time of diagnosis, route of infection, underlying diseases, affected limbs, clinical manifestations and signs on admission, white blood cell count, hemoglobin, platelet count, C-reactive protein (CRP), alanine transaminase (ALT), aspartate transaminase (AST), creatinine, procalcitonin, albumin, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and blood sodium levels on admission, culture results and metagenomic next-generation sequencing (mNGS) results of pathogenic bacteria and the Vibrio vulnificus drug susceptibility test results during hospitalization, treatment methods, length of hospital stay, and outcomes of all patients were recorded. Comparative analysis was conducted on the admission time and diagnosis time of patients with and without a history of exposure to seawater/marine products, as well as the fatality ratio and amputation of limbs/digits ratio of patients with and without early adequate antibiotic treatment. For the survived patients with hand involvement, the hand function was assessed using Brunnstrom staging at the last follow-up. Based on patients' clinical characteristics and treatment conditions, a rapid diagnosis procedure for Vibrio vulnificus infection was established. Results:There were 7 males and 4 females among the patients, aged (56±17) years. Most of the patients developed symptoms in summer and autumn. The admission time was 3.00 (1.00, 4.00) d after the onset of illness, and the diagnosis time was 4.00 (2.00, 8.00) d after the onset of illness. There were 7 and 4 patients with and without a history of contact with seawater/marine products, respectively, and the admission time of these two types of patients was similar ( P>0.05). The diagnosis time of patients with a history of contact with seawater/marine products was 2.00 (2.00, 5.00) d after the onset of illness, which was significantly shorter than 9.00 (4.25, 13.00) d after the onset of illness for patients without a history of contact with seawater/marine products ( Z=-2.01, P<0.05). Totally 10 patients had underlying diseases. The affected limbs were right-hand in 8 cases, left-hand in 1 case, and lower limb in 2 cases. On admission, a total of 9 patients had fever; 11 patients had pain at the infected site, and redness and swelling of the affected limb, and 9 patients each had ecchymosis/necrosis and blisters/blood blisters; 6 patients suffered from shock, and 2 patients developed multiple organ dysfunction syndrome. On admission, there were 8 patients with abnormal white blood cell count, hemoglobin, and albumin levels, 10 patients with abnormal CRP, procalcitonin, and NT-proBNP levels, 5 patients with abnormal creatinine and blood sodium levels, and fewer patients with abnormal platelet count, ALT, and AST levels. During hospitalization, 4 of the 11 wound tissue/exudation samples had positive pathogenic bacterial culture results, and the result reporting time was 5.00 (5.00, 5.00) d; 4 of the 9 blood specimens had positive pathogenic bacterial culture results, and the result reporting time was 3.50 (1.25, 5.00) d; the mNGS results of 7 wound tissue/exudation or blood samples were all positive, and the result reporting time was 1.00 (1.00, 2.00) d. The three strains of Vibrio vulnificus detected were sensitive to 10 commonly used clinical antibiotics, including ciprofloxacin, levofloxacin, and amikacin, etc. A total of 10 patients received surgical treatment, 4 of whom had amputation of limbs/digits; all patients received anti-infection treatment. The length of hospital stay of 11 patients was (26±11) d, of whom 9 patients were cured and 2 patients died. Compared with that of the 6 patients who did not receive early adequate antibiotic treatment, the 5 patients who received early adequate antibiotic treatment had no significant changes in the fatality ratio or amputation of limbs/digits ratio ( P>0.05). In 3 months to 2 years after surgery, the hand function of 8 patients was assessed, with results showing 4 cases of disabled hands, 2 cases of incompletely disabled hands, and 2 cases of recovered hands. When a patient had clinical symptoms of limb redness and swelling and a history of contact with seawater/marine products or a pre-examination triage RiCH score of Vibrio vulnificus sepsis ≥1, the etiological testing should be initiated immediately to quickly diagnose Vibrio vulnificus infection. Conclusions:Vibrio vulnificus infection occurs most frequently in summer and autumn, with clinical manifestations and laboratory test results showing obvious infection characteristics, and may be accompanied by damage to multiple organ functions. Both the fatality and disability ratios are high and have a great impact on the function of the affected limbs. Early diagnosis is difficult and treatment is easily delayed, but mNGS could facilitate rapid detection. For patients with red and swollen limbs accompanied by a history of contact with seawater/marine products or with a pre-examination triage RiCH score of Vibrio vulnificus sepsis ≥1, the etiological testing should be initiated immediately to quickly diagnose Vibrio vulnificus infection.