Research progress on electrical impedance tomography in pulmonary perfusion / 生物医学工程学杂志

Electrical impedance tomography (EIT) is an emerging technology for real-time monitoring based on the impedance differences of different tissues and organs in the human body. It has been initially applied in clinical research as well as disease diagnosis and treatment. Lung perfusion refers to the blood flow perfusion function of lung tissue, and the occurrence and development of many diseases are closely related to lung perfusion. Therefore, real-time monitoring of lung perfusion is particularly important. The application and development of EIT further promote the monitoring of lung perfusion, and related research has made great progress. This article reviews the principles of EIT imaging, lung perfusion imaging methods, and their clinical applications in recent years, with the aim of providing assistance to clinical and scientific researchers.

The Empirical Research Path of Yin-Yang Thinking in Traditional Chinese Medicine / 中医杂志

The yin-yang theory is a thinking model used by ancient people to recognize the world， which is highly compatible with multimodal metaphors. By summarizing the current researches on traditional Chinese medicine （TCM） yin-yang theory and thinking， it is found that there are more clinical researches but few empirical studies， and more conceptual studies but few empirical researches. In view of this， we proposed to conduct researches on TCM yin-yang thinking with the methods such as behavioral experiments， event-related potentials， and functional magnetic resonance imaging techniques， based on the multimodal metaphor theory from the perspective of cognitive science. According to the characteristics of yin-yang， the process of TCM yin-yang thinking is divided into two stages which are yin-yang classification and yin-yang reasoning， and the main directions of empirical research on yin-yang thinking in TCM are outlined by combining with the paradigm of cognitive science， that is， the researches are carried out from the cognitive characteristics of TCM yin-yang thinking， as well as the differences in cognitive mechanisms between TCM yin-yang thinking and western logical thinking.

CRISPR-assisted transcription activation by phase-separation proteins

The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system has been widely used for genome engineering and transcriptional regulation in many different organisms. Current CRISPR-activation (CRISPRa) platforms often require multiple components because of inefficient transcriptional activation. Here, we fused different phase-separation proteins to dCas9-VPR (dCas9-VP64-P65-RTA) and observed robust increases in transcriptional activation efficiency. Notably, human NUP98 (nucleoporin 98) and FUS (fused in sarcoma) IDR domains were best at enhancing dCas9-VPR activity, with dCas9-VPR-FUS IDR (VPRF) outperforming the other CRISPRa systems tested in this study in both activation efficiency and system simplicity. dCas9-VPRF overcomes the target strand bias and widens gRNA designing windows without affecting the off-target effect of dCas9-VPR. These findings demonstrate the feasibility of using phase-separation proteins to assist in the regulation of gene expression and support the broad appeal of the dCas9-VPRF system in basic and clinical applications.

Preimplantation genetic testing for monogenic/single gene disorders in a family with Molybdenum co-factor deficiency / 中华医学遗传学杂志

OBJECTIVE@#To carry out preimplantation genetic testing for monogenic/single gene disorders (PGT-M) for a Chinese family affected with Molybdenum co-factor deficiency due to pathogenic variant of MOCS2 gene.@*METHODS@#A family with molybdenum co-factor deficiency who attended to the Maternal and Child Health Care Hospital of Guangxi Zhuang Autonomous Region in April 2020 was selected as the research subject. Trophoblast cells were biopsied from blastocysts fertilized by intracytoplasmic sperm injection. Embryos carrying the MOCS2 gene variant and chromosome copy number variation (CNV) of more than 4 Mb were detected by single-cell whole genome amplification, high-throughput sequencing and single nucleotide polymorphism typing. Embryos without or carrying the heterozygous variant and without abnormal chromosome CNV were transplanted. During mid-pregnancy, amniotic fluid sample was collected for prenatal diagnosis to verify the results of PGT-M.@*RESULTS@#Eleven oocytes were obtained, among which three blastocysts were formed through culturing. Results of genetic testing suggested that one embryo was heterozygous for the maternally derived MOCS2 gene variant and without chromosomal CNV. Following embryo transfer, intrauterine singleton pregnancy was attained. Prenatal diagnosis by amniocentesis at 18 weeks of gestation revealed that the MOCS2 gene variant and chromosomal analysis results were both consistent with that of PGT-M, and a healthy male infant was born at 37+5 weeks of gestation.@*CONCLUSION@#PGT-M has helped the couple carrying the MOCS2 gene variant to have a healthy offspring, and may become an important method for couples carrying other pathogenic genetic variants.

Assessment of occupational health risk of noise in a plastic products enterprise / 中国职业医学

@#Objective To assess the occupational health risk of noise in a plastic products enterprise and determine the key risk Methods - points. The workplace of a plastic products enterprise and its 388 noise exposed workers were selected as the ， research subjects using a convenient sampling method. The noise intensity in the workplace of the enterprise was measured and - GBZ/T 229.4-2012 the individual noise exposure level and pure tone hearing test were carried out in the noise exposed workers. Classification of Occupational Hazards at Workplaces--Part 4： Occupational Exposure to Noise（ GBZ/T hereinafter referred to as 229.4-2012） - was used to evaluate the hazardous degree of noise in different posts. The risk of high frequency hearing loss （ ） - （ ） - ， ， HFHL and occupational noise induced deafness ONID in noise exposed workers in different posts at 45.0 50.0 55.0 and WS/T 754-2016 Guideline for Risk Management of Occupational Noise Hazard（ 60.0 years of age were predicted using hereinafter WS/T 754-2016）Results referred to as . The noise in the workplace of this plastic product enterprise was found to exceed the - occupational exposure limits with the rate of 46.6%. The maximum level of normalization of equivalent continuous A weighted - （ ） sound pressure level to a nominal 40 h working week of exposure to noise in workers of six posts was 84.0 93.0 dB A . - ， ， ， According to GBZ/T 229.4 2012 the noise hazards of the posts including extrusion premixing unloading and utility - ， maintenance were mild or moderate except for the film and packaging posts. According to WS/T 754 2016 the risks of HFHL in ， ， the film and packaging operators at age ≥50.0 years old were at acceptable risk and the risks of HFHL in operators of extrusion ， ， premixing unloading and utility maintenance at age ≥45.0 years old were at moderate risk or high risk. The risks of ONID for ， the film packaging and utility maintenance operators at age ≥55.0 years old were at acceptable risk or moderate risk. The risksof ONID for extrusion premixing and unloading operators at age ≥50.0 years old were at high risk. Extrusion operators with （ ） exposure to toluene below the occupational exposure limit had a higher risk of HFHL high risk than unloading operators （ ） Conclusion moderate risk at age 45.0 years with the same noise intensity. The noise exposure intensity is high in the ， workplace of the plastic product enterprise. The workers in posts of extrusion premixing and unloading are at high risk levels of HFHL and ONID.

Feasibility study on BN rats and RBL-2H3 cells as models of allergic reaction to Yin Zhihuang injection / 中国药理学通报

Aim To explore the establishment of BN rat animal model and RBL-2H3 cell model of allergic reaction to Yinzhihuang injection. Methods ASA test was performed to compare the symptoms and grades of allergic reactions in BN rats and Hartley guinea pigs, and serum IgE and histamine levels were detected. The amount of histamine released from RBL-2H3 cell supernatant was measured after Yinzhihuang injection affected, and the intracellular Ca

Effects of the ITGA2B Nonsense Mutation (c.2659C > T, p.Q887X) on Platelet Function in a Mouse Model of Glanzmann's Thrombasthenia Generated with CRISPR/Cas9 Technology / 中国实验血液学杂志

OBJECTIVE@#To construct a mouse model of Glanzmann's thrombasthenia (GT) with ITGA2B c.2659 C>T (p.Q887X) nonsense mutation by CRISPR/Cas9 technology, and then further explore the expression and function of glycoprotein αIIbβ3 on the surface of platelet membrane.@*METHODS@#The donor oligonucleotide and gRNA vector were designed and synthesized according to the ITGA2B gene sequence. The gRNA and Cas9 mRNA were injected into fertilized eggs with donor oligonucleotide and then sent back to the oviduct of surrogate mouse. Positive F0 mice were confirmed by PCR genotyping and sequence analysis after birth. The F1 generation of heterozygous GT mice were obtained by PCR and sequencing from F0 bred with WT mice, and then homozygous GT mice and WT mice were obtained by mating with each other. The phenotype of the model was then further verified by detecting tail hemorrhage time, saphenous vein bleeding time, platelet aggregation, expression and function of αIIbβ3 on the surface of platelet.@*RESULTS@#The bleeding time of GT mice was significantly longer than that of WT mice (P<0.01). Induced by collagen, thrombin, and adenosine diphosphate (ADP), platelet aggregation in GT mice was significantly inhibited (P<0.01, P<0.01, P<0.05). Flow cytometry analysis showed that the expression of αIIbβ3 on the platelet surface of GT mice decreased significantly compared with WT mice (P<0.01), and binding amounts of activated platelets to fibrinogen were significantly reduced after thrombin stimulation (P<0.01). The spreading area of platelet on fibrinogen in GT mice was significantly smaller than that in WT mice (P<0.05).@*CONCLUSION@#A GT mouse model with ITGA2B c.2659 C>T (p.Q887X) nonsense mutation has been established successfully by CRISPR/Cas9 technology. The aggregation function of platelet in this model is defective, which is consistent with GT performance.

Clinical Efficacy of High Dose Methotrexate, Temozolomide and Rituximab in the Treatment of Patients with Primary Central Nervous System Lymphoma / 中国实验血液学杂志

OBJECTIVE@#To investigate the clinical efficacy of high dose methotrexate (HD-MTX), temozolomide (TMZ), and rituximab (R) in the treatment of patients with primary central nervous system lymphoma (PCNSL).@*METHODS@#Clinical data of patients with PCNSL diagnosed and treated in Guangdong Provincial People's Hospital from February 2010 to May 2017 were collected. First, patients were given 6-8 cycles of MTX (3.5 g/m@*RESULTS@#There were 42 patients enrolled in the study, 17 cases in HD-MTX+TMZ group and 25 cases in HD-MTX+TMZ+R group. The median PFS and OS times in HD-MTX+TMZ+R group were 56.7 months and N/A, respectively, while, 7.3 months and 34.7 months in HD-MTX+TMZ group, respectively. In addition, there was no significant difference in median survival between patients who received TMZ maintenance therapy and those who were only actively monitored. During the induction period, all the patients had grade 1-2 nausea and vomiting, while in the consolidation treatment period, no grade 3/4 toxicity was observed.@*CONCLUSION@#The combination of HD-MTX+TMZ+R in the treatment of PCNSL patients shows a definite short-term effect, which can increase the survival rate of the patients. The side effects are mild, and the patients can generally tolerate.

Obstetric Diseases Responding Specifically to Traditional Chinese Medicine / 中国实验方剂学杂志

In recent years， with the change in life style， social environment， and national childbearing policy， the proportion of high-risk pregnant women has increased significantly， triggering the spectrum of obstetric diseases to constantly change， which has brought new challenges to the diagnosis and treatment of obstetrics. Traditional Chinese medicine （TCM） has been proved effective in dealing with a variety of obstetric diseases， and various treatment methods are available， which can serve as alternative means for solving refractory obstetric diseases. However， most obstetric clinicians are currently less aware of the therapeutic effects of TCM， which has significantly hindered its participation in clinical treatment. Therefore， the China Association of Chinese Medicine （CACM） organized the outstanding young obstetricians of TCM and western medicine to discuss 15 obstetric diseases responding specifically to TCM or integrated TCM and western medicine， including hyperemesis gravidarum， threatened abortion， ectopic gestation， cough during pregnancy， pregnancy-induced hypertension syndrome， maternal-fetal ABO incompatibility， postpartum hypogalactia， residual pregnancy tissue in uterine cavity， puerperal infection， pantalgia after childbirth， hematoma/undesirable healing after caesarean section， postpartum urinary retention， ileus after cesarean section， pelvic floor dysfunction， and postnatal depression. The suggestions for their treatment with TCM or integrated TCM and western medicine were also proposed， aiming to provide patients with effective and personalized treatments in clinical practice and improve the diagnosis and treatment effects of obstetric diseases， thus benefiting the public. At the same time， more obstetrical clinicians are expected to understand the therapeutic effects and advantages of TCM and draw on the strengths of both TCM and western， thereby promoting the establishment of an obstetric diagnosis and treatment system with Chinese characteristics.

The semi-quantitative risk assessment of Listeria monocytogenes contamination in cooked meat products in bulk in Zhejiang Province / 预防医学

Objective@#To investigate the contamination status and assess the potential consumption risk of Listeria monocytogenes ( L. monocytogenes ) in cooked meat products in bulk in Zhejiang Province, so as to provide strategy for food safety supervision and management.@*Methods@#A total of 2 320 cooked meat products were sampled from eleven cities in Zhejiang Province during 2018-2020. The detection of L. monocytogenes was carried out in accordance with the national standard GB/T 4789.30-2016. Risk Ranger software was used for the semi-quantitative risk assessment on the whole population and pregnant women.@*Results@#The total detection rate of L. monocytogenes in cooked meat products in bulk in Zhejiang Province was 2.97% ( 69/2 320 ). The detection rates in stewed, smoked/roasted, fried, dried products and others were 3.85%, 1.81%, 0.59%, 0% and 0.94%, which were significantly different ( P<0.05 ). There were 28 positive samples in 1 069 samples collected in 2020, with the concentration ranging from 5 to 590 CFU/g and averaging 6.8 CFU/g. The estimated number of listeriosis cases each year caused by consumption of cooked meat products in bulk was 131 in the whole population with a risk score of 42, and 1.44 in pregnant women with a risk score of 54. The risk coefficient could reduce to approximate zero after sufficient heating before intake.@*Conclusion@#The prevalence of L. monocytogenes in cooked meat products in bulk in Zhejiang Province during 2018-2020 poses a potential risk in food safety. Pregnant women should avoid eating.

Value of Head and Neck CT Angiography in the Clinical Evaluation of Intraoperative Bleeding Volume of Carotid Body Tumours / 中国医学科学院学报

To investigate the value of head and neck CT angiography(CTA)in the evaluation of intraoperative hemorrhage of carotid body tumours. Head and neck CTA images of 36 patients with carotid body tumours confirmed by pathology were retrospectively analyzed.Patients were divided into two groups based on the intraoperative bleeding volume:<500 ml and≥500 ml groups.The patient's age,sex,Shamblin classification,size of the lesion,number of blood supply arteries,course of the disease,plain scan,and enhanced CT value between two groups were compared and analyzed.Logistics regression equation was established based on the CTA parameters with significant differences between the two intraoperative bleeding volume groups,and combined parameter was acquired.The receiver operating characteristic curve was established based on CTA single and combined parameters. The bleeding volume during the operation of carotid body tumors was significantly correlated with the age of patients(=0.019),the maximum diameter of tumours on axial images(=0.003),the maximum upper and lower diameters(=0.004),Shamblin classification(=0.012),and number of blood supply arteries(<0.001).The area under the receiver operating characteristic curve of the number of feeding arteries,the maximum diameter of axial images,maximum upper and lower diameters,Shamblin classification,and combined parameters were 0.865,0.781,0.806,0.766,and 0.927,respectively.When the optimal critical value was 0.408,the Youden index was 0.794,and the corresponding accuracy,sensitivity,and specificity were 0.919,0.909,and 0.923,respectively. Preoperative head and neck CTA can be used to evaluate the intraoperative blood loss.Combined parameters has the best diagnostic performance compared with single parameters.

Diagnostic value of 18F-FDG PET/CT and tumor markers (CEA, CA19-9, CA24-2) in recurrence and metastasis of postoperative colorectal moderately differentiated adenocarcinoma / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the diagnostic value of 18F-FDG PET/CT and tumor markers (CEA,CA19-9,CA24-2) in detection for recurrence and metastasis of postoperative colorectal moderately differentiated adenocarcinoma.@*METHODS@#Fifty-five patients were enrolled in this study. All of the patients were tested with serum CEA within 2 weeks when they underwent 18F-FDG PET/CT scan, and some patients were tested with serum CA19-9 and CA24-2 simultaneously. According to the pathology and clinical results of their follow-up, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 18F-FDG PET/CT and tumor markers were calculated based on different divided groups, respectively.@*RESULTS@#According to the pathology and the results of their clinical follow-up, the sensitivity of 18F-FDG PET/CT, CEA, CA19-9, CA24-2 and the combination of those three tumor markers were 95.74%, 68.09%, 28.57%, 40.00% and 74.47%, respectively. The specificity of 18F-FDG PET/CT, CEA, CA19-9, CA24-2 and the combination of those three tumor markers were 75.00%, 50.00%, 66.67%, 71.43% and 50.00%, respectively. The positive predictive valueof 18F-FDG PET/CT, CEA, CA19-9, CA24-2 and the combination of those three tumor markers were 95.74%, 88.89%, 85.71%, 88.89% and 89.74%, respectively. The negative predictive value of 18F-FDG PET/CT, CEA, CA19-9, CA24-2 and the combination of those three tumor markers were 75.00%, 26.67%, 11.42%, 17.24%, 25.00%, respectively. The accuracy of 18F-FDG PET/CT, CEA, CA19-9, CA24-2 and the combination of those three tumor markers were 92.73%, 65.47%, 32.65%, 44.68% and 70.91%, respectively. There were 2 cases of false positive and 2 cases of false negative in 18F-FDG PET/CT.@*CONCLUSION@#18F-FDG PET/CT has high value in detecting recurrence and metastasis of postoperative colorectal carcinoma. Tumor markers have the positive value to imply the recurrence and metastasis of postoperative colorectal carcinoma and are useful to indicate when to perform the 18F-FDG PET/CT. The combination of tumor markers could improve the diagnostic efficiency to some extent.

Determination of plasma antiglycan autoantibodies in patients with IgA nephropathy and the correlation with clinical characteristics / 中华肾脏病杂志

Objective To establish the measurement of IgA1 O-glycan-specific antiglycan autoantibodies in patients with IgA nephropathy (IgAN),and evaluate their role in the development and progression of IgAN.Methods In the IgAN regular follow-up cohort of Peking University Institute of Nephrology from January 2006 to December 2015,170 patients drawn by stratified randomization were enrolled in this study.Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of plasma galactose-deficient IgA1 (Gd-IgA1) and antiglycan autoantibody (IgG and IgA1).The correlation between antiglycan autoantibodies and clinicopathological parameters was analyzed by linear correlation and multiple linear regression analysis.The receiver operating characteristic curve (ROC) was used to evaluate the value of plasma anti glycide antibodies in the diagnosis of IgAN.Results IgG and IgA1 antiglycan antoantibodies that specifically recognized Fab-hinge region (Fab-HR) antigens could be detected in both IgAN and healthy control group.Agglutinin inhibition test showed that the specific antigen epitope was N-acetylgalactosamine (GalNAc) residue exposed to galactose deficiency in IgA1 hinged region.There was no significant difference in the absolute levels of plasma IgG antiglycan autoantibodies between IgAN and healthy controls (P=0.963).After adjustment of the plasma level of IgG,the normalized antiglycan autoantibody (ln[IgG antiglycan antibody/IgG]) in patients with IgANwas significantly higher than that in healthy controls (0.58±0.31 vs 0.37±0.11,P ＜ 0.01).The normalized level of IgG antiglycan autoantibody in IgAN patients was positively correlated with 24 h urine protein level during renal biopsy (Spearman r=0.183,P ＜ 0.05),and was also significantly correlated with 24 h urinary protein level after adjusting for baseline clinical and pathological factors (β=0.713,95％CI 0.323-1.102,P ＜ 0.01).The area under ROC curve (AUC) of normalized IgG antiglycan autoantibody in the diagnosis of IgAN was 0.764 (95％ CI 0.682-0.845,P ＜ 0.05).Using the cut-off value of 0.396,the sensitivity and specificity of normalized IgG antiglycan autoantibody for IgAN were 0.729 and 0.700 respectively.There was no significant difference in the absolute or normalized levels of IgA1 antiglycan autoantibodies between IgAN patients and healthy controls.Conclusions Gd-IgA1-specific antiglycan autoantibodies can be detected both in IgAN patients and healthy controls.They are elevated in some patients with IgAN and possibly involved in the development of IgAN.

Evaluation of activity of botulinum neurotoxin A based on primary cerebellar granu-losa cells / 军事医学

Objective To isolate and culture the primary cerebellar granulosa cells(CGNs)of SD rats and evaluate the activity of botulinum neurotoxin A(BoNT/A)based on CGNs.Methods CGNs of 6-to 8-days-old SD rats were isolated and cultured.After 5-7 d,the cells were treated with BoNT/A.The activity of the toxin was evaluated with immunofluo-rescence,and the relationships between the activity and dose of the toxin were analyzed with Western blotting.Results and Conclusion CGNs Of SD rats were successfully cultured,a method for evaluating the activity of BoNT/A was established at the level of primary nerve cells,and the relationships between the activity and dose of toxin were analyzed.This study provides a tool for further detailing the biochemical mechanism of BoNT /A.

Lipoxin A4 Ameliorates Lipopolysaccharide-Induced A549 Cell Injury through Upregulation of N-myc Downstream-Regulated Gene-1 / 中华医学杂志(英文版)

<p><b>Background</b>Lipoxin A4 (LXA4) can alleviate lipopolysaccharide (LPS)-induced acute lung injury (ALI) and acute respiratory distress syndrome through promoting epithelial sodium channel (ENaC) expression in lung epithelial cells. However, how LXA4 promote ENaC expression is still largely elusive. The present study aimed to explore genes and signaling pathway involved in regulating ENaC expression induced by LXA4.</p><p><b>Methods</b>A549 cells were incubated with LPS and LXA4, or in combination, and analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) of ENaC-α/γ. Candidate genes affected by LXA4 were explored by transcriptome sequencing of A549 cells. The critical candidate gene was validated by qRT-PCR and Western blot analysis of A549 cells treated with LPS and LXA4 at different concentrations and time intervals. LXA4 receptor (ALX) inhibitor BOC-2 was used to test induction of candidate gene by LXA4. Candidate gene siRNA was adopted to analyze its influence on A549 viability and ENaC-α expression. Phosphoinositide 3-kinase (PI3K) inhibitor LY294002 was utilized to probe whether the PI3K signaling pathway was involved in LXA4 induction of candidate gene expression.</p><p><b>Results</b>The A549 cell models of ALI were constructed and subjected to transcriptome sequencing. Among candidate genes, N-myc downstream-regulated gene-1 (NDRG1) was validated by real-time-PCR and Western blot. NDRG1 mRNA was elevated in a dose-dependent manner of LXA4, whereas BOC-2 antagonized NDRG1 expression induced by LXA4. NDRG1 siRNA suppressed viability of LPS-treated A549 cells (treatment vs. control, 0.605 ± 0.063 vs. 0.878 ± 0.083, P = 0.040) and ENaC-α expression (treatment vs. control, 0.458 ± 0.038 vs. 0.711 ± 0.035, P = 0.008). LY294002 inhibited NDRG1 (treatment vs. control, 0.459 ± 0.023 vs. 0.726 ± 0.020, P = 0.001) and ENaC-α (treatment vs. control, 0.236 ± 0.021 vs. 0.814 ± 0.025, P < 0.001) expressions and serum- and glucocorticoid-inducible kinase 1 phosphorylation (treatment vs. control, 0.442 ± 0.024 vs. 1.046 ± 0.082, P = 0.002), indicating the PI3K signaling pathway was involved in regulating NDRG1 expression induced by LXA4.</p><p><b>Conclusion</b>Our research uncovered a critical role of NDRG1 in LXA4 alleviation of LPS-induced A549 cell injury through mediating PI3K signaling to restore ENaC expression.</p>

Dexmedetomidine preconditioning protects against lipopolysaccharides-induced injury in the human alveolar epithelial cells / Pré-condicionamento com dexmedetomidina protege contra lesões induzidas por lipopolissacarídeos em células epiteliais alveolares humanas

Abstract Background and objectives Dexmedetomidine (DEX) has demonstrated the preconditioning effect and shown protective effects against organize injury. In this study, using A549 (human alveolar epithelial cell) cell lines, we investigated whether DEX preconditioning protected against acute lung injury (ALI) in vitro. Methods A549 were randomly divided into four groups (n = 5): control group, DEX group, lipopolysaccharides (LPS) group, and D-LPS (DEX + LPS) group. Phosphate buffer saline (PBS) or DEX were administered. After 2 h preconditioning, the medium was refreshed and the cells were challenged with LPS for 24 h on the LPS and D-LPS group. Then the malondialdehyde (MDA), superoxide dismutase (SOD), Bcl-2, Bax, caspase-3 and the cytochrome c in the A549 were tested. The apoptosis was also evaluated in the cells. Results Compare with LPS group, DEX preconditioning reduced the apoptosis (26.43% ± 1.05% vs. 33.58% ± 1.16%, p < 0.05) in the A549, which is correlated with decreased MDA (12.84 ± 1.05 vs. 19.16 ± 1.89 nmoL.mg-1 protein, p < 0.05) and increased SOD activity (30.28 ± 2.38 vs. 20.86 ± 2.19 U.mg-1 protein, p < 0.05). DEX preconditioning also increased the Bcl-2 level (0.53 ± 0.03 vs. 0.32 ± 0.04, p < 0.05) and decreased the level of Bax (0.49 ± 0.04 vs. 0.65 ± 0.04, p < 0.05), caspase-3 (0.54 ± 0.04 vs. 0.76 ± 0.04, p < 0.05) and cytochrome c. Conclusion DEX preconditioning has a protective effect against ALI in vitro. The potential mechanisms involved are the inhibition of cell death and improvement of antioxidation.

Resumo Justificativa e objetivos Dexmedetomidina (DEX) demonstrou ter efeito pré-condicionante e também efeitos protetores contra lesão organizada. Neste estudo, com células A549 (células epiteliais alveolares humanas), investigamos se o pré-condicionamento com DEX proporcionaria proteção contra lesão pulmonar aguda (LPA) in vitro. Métodos Células A549 foram aleatoriamente distribuídas em quatro grupos (n = 5): controle, DEX, lipopolissacarídeos (LPS) e D-LPS (DEX + LPS). Administramos solução de PBS (tampão fosfato-alcalino) ou DEX. Após 2 h de pré-condicionamento, o meio foi renovado e as células desafiadas com LPS por 24 h nos grupos LPS e D-LPS. Em seguida, malondialdeído (MDA), superóxido dismutase (SOD), Bcl-2, Bax, caspase-3 e em A549 foram testados. Apoptose também foi avaliada nas células. Resultados Em comparação com o grupo LPS, o pré-condicionamento com DEX reduziu a apoptose (26,43% ± 1,05% vs. 33,58% ± 1,16%, p < 0,05) em células A549, o que está correlacionado com a diminuição de MDA (12,84 ± 1,05 vs. 19,16 ± 1,89 nmol.mg-1 de proteína, p < 0,05) e aumento da atividade de SOD (30,28 ± 2,38 vs. 20,86 ± 2,19 U.mg-1 de proteína, p < 0,05). O pré-condicionamento com DEX também aumentou o nível de Bcl-2 (0,53 ± 0,03 vs. 0,32 ± 0,04, p < 0,05) e diminuiu o nível de Bax (0,49 ± 0,04 vs. 0,65 ± 0,04, p < 0,05), caspase-3 (0,54 ± 0,04 vs. 0,76 ± 0,04, p < 0,05) e citocromo c. Conclusão O pré-condicionamento com DEX tem efeito protetor contra LPA in vitro. Os potenciais mecanismos envolvidos são inibição da morte celular e melhoria da antioxidação.

Preincubation with low dose of hydrogen peroxide enhances anti-oxidative stress potential of mouse BMSCs / 基础医学与临床

Objective To investigate the effects of preconditioning with low-concentration hydrogen peroxide ( H2O2 ) on oxidative stress-induced bone marrow mesenchymal stem cells ( BMSCs ) apoptosis and its mecha-nism.Methods Mouse bone marrow mesenchymal stem cells ( BMSCs) were isolated and purified by differential centrifugation, and were treated with 0,200,250,300, 500 μmol/L H2O2 after preincubation with 50 μmol/L H2O2 or control medium.Apoptosis of these cells was measured by flow cytometry, and the expression of phos-phorylated PI3K, Akt and mTOR was analyzed by Western blot; BMSCs were also primed with PI3K inhibitor LY294002 for 30 min, then preincubated with 50 μmol/L H2O2 or control medium for 12 h before treatment with 300 μmol/L H2O2.Expression of apoptosis proteins Bcl-2, Bax, caspaase-3, cleaved-caspase-3 and the key pro-teins of the PI3K/Akt/mTOR pathway were detected by Western blot .Results H2O2 induced BMSCs apoptosis in a dose-dependent manner ,and pretreatment of BMSCs with low concentration of H2O2 significantly decreased H2O2-induced apoptosis of the BMSCs .Western blot results revealed that preconditioning with low-concentration H2O2 re-markably reversed the decrease in Bcl-2, total and phosphorylated PI3K, Akt and mTOR levels, and increased in Bax, cleaved-caspase-3 expression after high-dose H2O2 treatment.Such effects were antagonized by PI3K inhibitor LY294002 .Conclusions Preincubation with low-concentration H2O2 may indnce resistance of BMSC to oxidative stress, and such effect may be mediated by inhibition of pro-apoptotic proteins and activation of the PI 3K/Akt/mTOR pathway .

Role of enterohemorrhagic E.coli toxin gene z5150 in cell adhesion / 军事医学

Objective To construct EHEC△z5150 using Red recombination and explore its pathogenicity.Methods Overexpression of the z5150 gene was used to test its toxicity.The kanamycin resistant gene flanked by homologues of target genes was amplified by PCR before being transferred into EHEC containing pKD 46 plasmid,and the target fragments were recombined into genome by Arabia sugar.The kanamycin resistance gene was removed by pFLP 2 plasmid mediated FLP site-specific recombination.Cell adhesion ability and virulence of the mutant were detected by infecting HT 29 cells and BALB/c female mice,respectively.Results and Conclusion The mutant strain EHEC △z5150 was successfully constructed.The absence of z5150 did not affect the normal growth of bacteria,but after excessive expression,it inhibited the growth.Deletion of z5150 showed significant difference in intestinal epithelial cell adhesion and pathogenicity compared with wild strain.This study provides a gene knockout technique for the study of EHEC gene function and of the relationships between RelEz5150 and EHEC pathogenicity.

Myeloid-derived suppressor cells promoted autologous B cell proliferation in rheumatoid arthritis / 北京大学学报(医学版)

Objective:To investigate the effect of myeloid-derived suppressor cells (MDSC) on pro liferation of B lymphocytes in rheumatoid arthritis (RA) patients.Methods:The peripheral blood specimens were collected from 15 healthy adults and 38 RA patients who were divided into high disease activity group,medium activity group and low activity group according to their 28-joint disease activity score (DAS28).And the frequencies of MDSC were determined by flow cytometry.Then,B cells and MDSC were isolated by flow cytometry,respectively.B cells were labeled with carboxyfluorescein diacetate suecinimidyl ester (CFSE) and then were co-cultured with MDSC in the presence of 3 mg/L anti-CD40 antibody and 10 mg/L CpG,for 3 days.Flow cytometry was performed to investigate the proliferation of B cells.Results:MDSC expanded markedly in high disease activity patients (7.13％ ±2.17％) compared with medium (5.35％ ±-1.36％) and low disease activity patients (4.72％ ± 1.08％) or healthy controls (4.79％ ± 1.02％) (P ＜ 0.05),and there were no statistical differences between healthy controls,medium and low disease activity RA (P ＞ 0.05).Moreover,the frequencies of MDSC were positively correlated with the DAS28 (P ＜ 0.05).After co-culture,MDSC significantly promoted B cell proliferation (P ＜0.01).Conclusion:Our studies showed that MDSC expanded obviously in high disease activity RA patients,and their frequencies were positively correlated with the disease activities.Furthermore,MDSC could promote autologous B cell proliferation remarkably in vitro.These findings suggest that MDSC might be involved in RA pathogenesis through regulating B cell functions.

Changes of serum Krebs von den Lungen-6 levels in interstitial lung disease associated with dermatomyositis and secondary Sj(o)gren's syndrome: a case report / 北京大学学报(医学版)

Interstitial lung diseases (ILDs) are a diverse group of pulmonary disorders characterized by various patterns of inflammation and fibrosis in the interstitium of the lung.The underlying pathogene sis of ILDs is complex and associated with multiple rheumatologic conditions,such as systemic sclerosis,rheumatoid arthritis,pollymyositis and dermatomyositis,Sjt(o)gren's syndrome,and systemic lupus erythematosus.As the disease progresses,excessive pulmonary fibrosis impairs alveolar gas exchange and damages pulmonary function.The common methods to diagnose ILDs,such as clinical manifestations,pulmonary function test,and radiological examinations are not specific for ILDs and not able to diagnose ILDs at the early stage due to their low sensitivity.So,the easy way is important to diagnose ILDs.One important biomarker for ILDs is the high-molecular-weight glycoprotein,Krebs von den Lungen-6 (KL-6).KL-6 encoded by the MUC1 gene is a mucin-like glycoprotein with high molecular weight and expressed predominantly on the cell surface of type Ⅱ alveolar epithelial cells,and is detectable in the serum of patients with ILDs.We here report a case of ILDs associated with dermatomyositis and secondary Sj(o)gren's syndrome.A 60-year-old woman was admitted to our hospital with the chief complaints of debilitation,dry mouth,dyspnea and astasia.ILDs associated with dermatomyositis and secondary Sj(o)gren's syndrome was diagnosed clinically when the following criteria were satisfied:(1) development of dyspnea within 2 months of presentation,(2) pulmonary dispersion dysfunction,(3) bilateral infiltrative shadows on chest high resolution computed tomography (HRCT).She was treated with prednisone 50 mg/d prior to admission,but the result of therapy was not good.In our hospital she was treated with intravenous methylprednisolone and cyclophosphamide and oral hydroxychloroquine sulfate.Subsequently,her serum KL-6 levels gradually decreased after treatment,pulmonary diffuse function improved,and the improvement in the clinical manifestation and HRCT findings were observed.Nevertheless,the combination treatment of glucocorticoid and cyclophosphamide had contributed to the favourable outcomes.In conclusion,detection of serum KL-6 levels in ILDs associated with connective tissue diseases may be beneficial to making a definitive diagnosis,predicting the prognosis and monitoring the disease activity,which would be of great help in clinical practice.However,a well-designed clinical study with more patients and a longer follow-up period are required to arrive at a more conclusive judgment on the role of serum KL-6 in patients with ILDs.