Signal transducer and activator of transcription 6 mediates skeletal muscle cell injury in septic mice by regulating ferroptosis / 中华危重病急救医学

Objective:To explore the effect of signal transducer and activator of transcription 6 (STAT6) on ferroptosis in skeletal muscle cells in sepsis model and its potential mechanism.Methods:Twenty-four 8-week-old male specific pathogen free Kunming mice were divided into normal control group, sham group, sepsis model group and STAT6 inhibitor pretreatment group according to random number table method with 6 mice in each group. A mouse sepsis model was reproduced by cecal ligation and perforation (CLP). In the sham group, the skin of mice was sutured after exposing the cecum tissue. In the STAT6 inhibitor pretreatment group, 10 mg/kg AS1517499 was injected intraperitoneally 1 hour before model reproduction. The sham group and the model group were intraperitoneally injected with the same volume of normal saline. Mice in the normal control group did not receive any operation or drug intervention. The mice were sacrificed 24 hours after model reproduction, and the muscle tissue of hind limb was obtained under sterile condition. Hematoxylin-eosin (HE) staining was used to observe the histopathology with optical microscope, and mitochondrial morphological changes were observed by transmission electron microscopy after double staining with uranium acetate lead citrate. The ferroptosis marker proteins expressions of chitinase-3-like protein 1 (CHI3L1), cyclooxygenase-2 (COX-2), acyl-CoA synthetase long-chain family member 4 (ACSL4), ferritin heavy chain 1 (FTH1), and glutathione peroxidase 4 (GPx4) were detected by Western blotting.Results:Under the optical microscope, the morphology and structure of skeletal muscle tissues in the normal control and sham groups were normal. In the model group, the structure of skeletal muscle tissues was loose, the muscle fiber became smaller and atrophic, inflammatory cell infiltration and even muscle fiber loss were found. Compared with the model group, the structure of skeletal muscle tissues was tight and skeletal muscle atrophy was improved in the STAT6 inhibitor pretreatment group. The ultrastructure of skeletal muscle cell in the normal control and sham groups was normal under transmission electron microscope. The ultrastructure characteristics of skeletal muscle in the model group showed that cell membrane was broken and blister, mitochondria became smaller and membrane density increased, the mitochondrial crista decreased or disappeared, the mitochondrial outer membrane was broken, and the nucleus was normal in size but lacked chromatin condensation. Compared with the model group, the STAT6 inhibitor pretreatment group had a significant improvement in the ultrastructure of muscle cells. Compared with the normal control and sham groups, the protein expressions of CHI3L1, COX-2, ACSL4 and FTH1 in the muscle of the model group were significantly increased, while the protein expression of GPx4 was decreased significantly, indicating that the skeletal muscle cells in the mouse sepsis model showed characteristic mitochondrial injury and abnormal expression of ferroptosis markers. Compared with the model group, the protein expressions of CHI3LI, COX-2, ACSL4 and FTH1 in the STAT6 inhibitor pretreatment group were significantly decreased [CHI3L1 protein (CHI3L1/GAPDH): 0.70±0.08 vs. 0.97±0.09, COX-2 protein (COX-2/GAPDH): 0.61±0.03 vs. 0.83±0.03, ACSL4 protein (ACSL4/GAPDH): 0.75±0.04 vs. 1.02±0.16, FTH1 protein (FTH1/GAPDH): 0.49±0.06 vs. 0.76±0.13, all P < 0.05], while the protein expression of GPx4 was significantly increased (GPx4/GAPDH: 1.14±0.29 vs. 0.53±0.03, P < 0.05). Conclusions:Sepsis can induce ferroptosis in skeletal muscle cells of mice. STAT6 may mediate ferroptosis in mouse skeletal muscle cells by regulating the expressions of COX-2, ACSL4, FTH1 and GPx4, thereby inducing skeletal muscle cell injury in sepsis.

Effects of chitinase-3-like protein 1 on the expression of inflammatory damage-related molecules in mouse skeletal muscle satellite cells induced by lipopolysaccharide / 中华危重病急救医学

Objective:To explore the potential mechanism of chitinase-3-like protein 1 (CHI3L1) involved in skeletal muscle stem cell injury induced by sepsis.Methods:Six different concentrations of lipopolysaccharide (LPS) were used to stimulate mouse skeletal muscle satellite cells cultured in vitro. Enzyme linked immunosorbent assay (ELISA) and cell counting kit-8 (CCK-8) were used to determine the optimal concentration. The overexpression and interference vectors of CHI3L1 were constructed to transfect skeletal muscle satellite cells, and the transfection efficiency was verified by polymerase chain reaction (PCR) and Western blotting. The cells were randomly divided into blank control group (cells without any intervention), model group (LPS-stimulated untransfected cells), overexpressing CHI3L1 group (LPS-stimulated cells transfected with CHI3L1 plasmid), overexpressing CHI3L1 control group [LPS-stimulated cells transfected with negative control (NC) plasmid], CHI3L1 interference group [LPS-stimulated cells transfected with CHI3L1 small interfering RNA (siRNA)], CHI3L1 interference control group (LPS-stimulated cells transfected with CHI3L1-siRNA NC). The levels of extracellular caspase-1 and interleukin-1β (IL-1β) were detected by ELISA. The protein expressions of intracellular IL-1β, signal transducer and activator of transcription 3 (STAT3), protein kinase B (Akt) and phosphorylated Akt (p-Akt) were detected by Western blotting. Results:According to the results of CCK-8 and ELISA, the best concentration of 5 mg/L LPS was selected for the subsequent experiment. The transfection was validated by PCR and Western blotting. Compared with the blank control group, the levels of extracellular IL-1β, caspase-1 and the protein expressions of intracellular Akt, p-Akt, and IL-1β were significantly increased in the model group [IL-1β (ng/L): 11.22±0.55 vs. 8.63±0.63, caspase-1 (pmol/L): 9.47±0.22 vs. 8.65±0.15, Akt/GAPDH: 1.36±0.12 vs. 1.06±0.15, p-Akt/GAPDH: 0.78±0.07 vs. 0.09±0.01, IL-1β/GAPDH: 1.38±0.12 vs. 0.18±0.03, all P < 0.05]. Compared with the model group and the overexpressing CHI3L1 control group, the levels of extracellular IL-1β, caspase-1 and the protein expressions of intracellular p-Akt and IL-1β were significantly increased in the overexpressing CHI3L1 group [IL-1β(ng/L): 14.93±0.97 vs. 11.22±0.55, 9.38±0.40, caspase-1 (pmol/L): 10.35±0.03 vs. 9.47±0.22, 8.46±0.24, p-Akt/GAPDH: 1.21±0.04 vs. 0.78±0.07, 0.63±0.04, IL-1β/GAPDH: 1.87±0.08 vs. 1.38±0.12, 1.51±0.17, all P < 0.05]. Compared with the model group and the CHI3L1 interference control group, the levels of extracellular IL-1β, caspase-1 and the protein expressions of intracellular p-Akt and IL-1β were significantly decreased in the CHI3L1 interference group [IL-1β(ng/L): 8.98±0.73 vs. 11.22±0.55, 10.44±0.65, caspase-1 (pmol/L): 7.61±0.63 vs. 9.47±0.22, 8.37±0.38, p-Akt/GAPDH: 0.50±0.04 vs. 0.78±0.07, 0.94±0.06, IL-1β/GAPDH: 0.77±0.02 vs. 1.38±0.12, 1.13±0.07, all P < 0.05]. Conclusions:CHI3L1 may mediate the damage of skeletal muscle stem cells in sepsis by increasing the expression of caspase-1 and IL-1β. CHI3L1 may be involved in the regulation of Akt signaling pathway in skeletal muscle stem cells, but has no significant effect on STAT3 signaling pathway.

Features of infection secondary to severe acute pancreatitis and related control strategies / 临床肝胆病杂志

Severe acute pancreatitis (SAP) is an acute abdominal disease and a critical illness commonly seen in clinical practice. Infection complications in the middle and late stages of SAP have a great impact on the prognosis of SAP and are often difficult to avoid. This article introduces the pathogenesis of secondary pancreatic and extra-pancreatic infections and summarizes the pathogen spectrum of infections secondary to SAP in the past 10 years. This article also summarizes and evaluates the current strategies for preventing secondary infections and briefly describes the advances in surgical interventions for SAP secondary infections. These analyses show that the pathogenesis, pathogenic features, and immunological features of SAP secondary infection remain unclear. There are various control strategies for such infection, but there are still no effective measures to prevent infection except early enteral nutrition. Conclusions will be achieved on the issues including the timing of percutaneous catheter drainage, and surgical interventions have developed rapidly on the basis of the STEP-UP approach. Endoscopic STEP-UP approach is slightly superior to conventional STEP-UP approach in the treatment of critically ill patients with SAP.

Negative regulation of microRNA - 9 by ecotropic viral integration site1 involved in the pathogenesis of acute myeloid leukemia / 中华实用儿科临床杂志

Objective To investigate the regulation mechanism of microRNA - 9(miR - 9)by ecotropic viral integration site1(EVI1)its impact on proliferation of AML cells and its role in the pathogenesis of myelogenous leuke-mia. Methods EVI1 was forced to express in Uocm1 cell lines by murine stem cell virus - EVI1(MSCV - EVI1) plasmid infection. EVI1 overexpressed Uocm1 cells were then treated with 0. 1 μmol/ L 5 - aza - 2′ - deoxycytidine (5 - AZA)dissolved in dimethyl sulfoxide (DMSO). The methylation level of miR - 9 promoter was tested by DNA bi-sulfite sequencing technology. The cell cycle was observed by flow cytometry (FCM). The proliferation ability of the cells was detected by the colony forming assay in semi - solid Methylcellulose medium culture. Results EVI1 level was dramatically increased after being infected by MSCV - EVI1 plasmid. Forced expression of EVI1 in Uocm1 signifi-cantly downregulated miR - 9 by inducing hypermethylation of miR - 9 promoter. Relative expression level of miR - 9 was lower in EVI1 overexpressed group(0. 004 ± 0. 000)than that of the control group(0. 006 ± 0. 001)(t = 4. 09,P <0. 05). When EVI1 was overexpressed in Uocm1,the rate of G0 / G1 cells decreased markedly(P < 0. 05),while rates of S phage and G2 phage increased significantly(all P < 0. 05). Seven days after 500 cells plated in semi - solid medium, EVI1 overexpressed Uocm1 cells gave rise to more colony (122. 3 ± 7. 8)than Uocm1 cells infected with vector (45. 7 ± 6. 1)(t = - 13. 44,P < 0. 01). 0. 1 μmol/ L 5 - AZA recovered miR - 9 expression(P < 0. 01)by decreasing EVI1 induced hypermethylation of miR - 9 promoter. G0 / G1 phase cell proportion was(48. 25 ± 2. 19)％ in control group,while (65. 90 ± 2. 90)％ in 5 - AZA group (t = - 6. 85,P < 0. 05). 5 - AZA group formed less colony (51. 00 ± 10. 01)than the control group (123. 40 ± 8. 12)(t = 9. 59,P < 0. 01),which indicated that 5 - AZA inhibi-ted cell proliferation by G0 / G1 cell cycle retardation in EVI1 overexpressed uocm1 cells. Conclusions EVI1 may en-hance proliferation ability of myeloid leukemia cells by downregulating miR - 9 through inducing hypermethylation of miR - 9 promotor,which plays a crucial role in the pathogenesis of AML. 5 - AZA may be an effective hypomethylating agent in the therapy of EVI1 high acute myeloid leukemia.

Clinical analysis of 122 acute brucellosis patients' blood culture / 中华地方病学杂志

Objective By studying the acute brucellosis patients' blood culture and the bacteria strains,we tried to confirm the bacteria strains,and to further explore the symptoms and the results of the treatment.Methods Totally 122 acute brucellosis patients were selected,who were in hospital in Heilongjiang Provincial Nongken General Hospital from 2012 to 2013.The patients aged 6-73 years old,whose average age was 36.5(including 83 males and 39 females).All of the subjects were detected in the aspects of blood culture and brucellosis serology,all of whom were treated with aminoglycoside,4-quinolones and cephalosporins.Results All the subjects were Brucella melitensis biovar,of which 104 were Brucella melitensis biovar 3,18 were Brucella melitensis biovar 1.All of them had positive results in rose bengal plate agglutination test (RBPT).In serum tube agglutination test (SAT),the valence of Brucella melitensis biovar 1 and 3 were uniformly distributed,Brucella melitensis biovar 1 was distributed mainly in 1∶800 valence zone,Brucella melitensis biovar 3 was distributed mainly in 1∶400 valence zone.The distribution trends in Coombs test and complement fixation test (CFT) were similar.In Coombs they were distributed mainly in 1∶800 valence zone,and in CFT were distributed mainly in 1∶40 zone.All of the subjects had typical symptoms of brucellosis,and had various kinds of complications (spondylitis,toxipathic hepatitis,et al).Totally 112 of them were recovered,and 10 were improved.Conclusion The human brucellosis in Heilongjiang Province is caused by Brucella melitensis biovar 1 and 3,with severe symptoms and various kinds of complications,earlier diagnose and treatment will have a better effect.

The practice and thinking on the standardized training of pediatric residents / 中华医学教育探索杂志

The standardized training for pediatric residents is a necessary route to promote their clinical ability and make them grow up.With the aim to improve the residents' basic theory,clinical skills and medical quality,we set up training plans according to the requirement of standardized training in shanghai,earnestly implement the related training in the process of training content,method,time node and stage appraisal system,formulating personalized training plan and implementing one to one teaching.Besides,we attach importance to the cultivation of scientific research and teaching ability of residents and set up a perfect evaluation system.Residents are required to obtain a certificate of training through the unified comprehensive examination before graduation.Here,the problems existing in the process of pediatric resident standardization training and preliminary countermeasures are also discussed.

Establishment of bone marrow failure mouse model and detection of FGF2 expression / 临床儿科杂志

Objective Previous study found that ifbroblast growth factor-2(FGF2) expression was at a low level in bone marrow of children with aplastic anemia. In this study, we established a bone marrow failure animal model to investigate whether FGF2 is involved in bone marrow failure. Methods BALB/c mice were irradiated by 5.0 Gy ray, and then infused with 1×106 lymphocytes from allogeneic mice lymph node. Peripheral blood cells and bone marrow mononuclear cells counting and bone marrow pathology were done. FGF2 protein in bone marrow mononuclear cells was measured by ELISA. Results Compared with the control group, the counting of hemoglobin, white blood cell, platelet and bone marrow mononuclear cell in aplastic anemia mouse model were signiifcantly deceased (P<0.05). Moreover, FGF2 expression in aplastic anemia mouse model were signiifcantly reduced (P<0.05). Conclusions 5.0 Gy ray irradiation and then 1×106 lymphocyte infusion in mice can induce bone marrow failure similar to the features of aplastic anemia. The low expression of FGF2 in bone marrow of aplastic anemia patients may play an important role in the pathogenesis of aplastic anemia.

Mental health status of relative donors versus unrelated donors before and after hematopoietic stem cell collection / 中国组织工程研究

BACKGROUND:Currently, hematopoietic stem celltransplantation mainly depends on unrelated donors. Mental state of the unrelated donors is very important to ensure the successful celltransplantation. OBJECTIVE:To compare mental and physical health status of relative and unrelated donors during the hematopoietic stem cellcol ection. METHODS:We compared the mental (Symptom Checklist-90) and physical (temperature, breath, pulse, and blood pressure) health status of relative and unrelated donors at admission, 1 day before cellcol ection, and 1-2 days after cellcol ection.RESULTS AND CONCLUSION:At admission, there was no difference in the mental health status of relative and unrelated donors (P>0.05), while the scores on Symptom Checklist-90 were significantly higher in the unrelated donors than the relative donors, including total score, forced, depression, anxiety, hostility, and fear (P<0.05). The physical signs were steady in the unrelated and relative donors, but the difference in breath and systolic blood pressure was of great significance before and after cellcol ection in the two groups. These findings indicate that during cellcol ection, the unrelated donors exhibit heavier mental load than the relative donors, and psychological counseling and health guidance are necessary.

Relationship between brucellosis arthritis of the hip and femoral head necrosis / 中华地方病学杂志

Objective To investigate the relationship between brucellosis arthritis of the hip and femoral head necrosis.Methods In August 2007 to August 2013,16 diagnosed and hospitalized patients with brucellosis complicated with femoral head necrosis in Heilongjiang Land Reclamation Bureau General Hospital were chosen as the objects of observation,and the patients' hospitalization information was analyzed retrospectively.Patients' medical records were investigated and analyzed.Observations included general condition of the patient,clinical symptoms and signs,imaging,pathology,treatment and curative effect.Results All the 16 patients had definite clinical manifestations of hip arthritis and femoral head necrosis including hip pain,limited mobility,positive 4 test,limp or bedridden,and sick limb muscle atrophy.Imaging examination:X-ray computer tomography (CT) showed cystic change and deformation collapse of femoral head.Magnetic resonance imaging(MRI) showed low signal on weighted T1 images,high signal on weighted T2 and soft tissue granulation hyperplasia could be seen in the hip joint.Pathological examination:most femoral bone tissue necrosis,dissolved,bone cells disappeared,a few bone cells present,and some fibrous tissue hyperplasia.Patients were treated with antibiotics according to the treatment principles of brucellosis,and the effect was obvious.Conclusions There is a causal relationship between brucellosis arthritis of the hip and femoral head necrosis.Therefore,positive and effective treatment of brucellosis arthritis of the hip in the early stages is crucial to prevent the occurrence of femoral head necrosis.

Application of PBL combined with medical simulation training in pediatrics practice teaching for long-schooling program / 中华医学教育探索杂志

Objective To explore the application value of PBL combined with medical simulation training in pediatric clinical practice for long-schooling program medical students.Methods Totally 41 long-schooling program medical students in pediatric department were taken as study group while 40 medical students as control group.PBL combined with medical simulation training was used in study group while traditional method was used in control group.Teaching effect was evaluated using score analysis,PBL learning performance rating scale and student questionnaire.Results Scores of theory test and clinical skill exam after course completion in study group were significantly higher than those of control group (P ＜ 0.01).PBL learning performance rating scale and student questionnaire showed that the student's comprehensive ability has significantly improved.Conclusions Application of PBL and medical simulation training in the pediatric clinical practice for long-schooling program medical students can enhance students' problem analyzing and summarizing abilities,problem-solving ability and practical operation ability.It can effectively cultivate team collaboration and doctor-patient communication skills as well as improve the quality of teaching.

Application value of CHN bone age in judicial identification / 中国法医学杂志

Objective Probe application value of CHN(the standards of skeletal maturity of hand and wrist for Chinese-CHN method)bone age in judicial identification,and analyze factors and related problems which influence its accuracy.Methods 522 patients participated in judicial identification of living age estimation.Two posteroanterior radiographs for the left wrist were shot with respective exposure value for all patients.And two oblique radiographs were added.Bone ages were estimated according to CHN method.Result Among 522 cases were 489 males and 33 females.Bone ages of 129 males reached to tiptop of CHN-18.4 and average bone age of other male patients is 16.5.Bone ages of 14 females reached to tiptop of CHN-17.3 and average bone age of other female patients is 15.7.Among 522 cases there were 388 patients with their CHN bone ages above 16.0,about 74.3%.The group of data indicates that multiple factors can influence accuracy of bone age estimation.Among them change of radiograph position and angle influenced estimation accuracy most.Conclusion If radiographs of high quality can be acquired,CHN method can be proficiently used,and radiologists can pay attention to the effect on estimation accuracy of epiphysis classification by change of radiograph position and angle,then CHN bone age can mostly meet requirements of living age estimation.