Structure-guided identification and characterization of potent inhibitors targeting PhoP and MtrA to combat mycobacteria

Mycobacteria are causative agents of tuberculosis (TB), which is a global health concern. Drug-resistant TB strains are rapidly emerging, thereby necessitating the urgent development of new drugs. Two-component signal transduction systems (TCSs) are signaling pathways involved in the regulation of various bacterial behaviors and responses to environmental stimuli. Applying specific inhibitors of TCSs can disrupt bacterial signaling, growth, and virulence, and can help combat drug-resistant TB. We conducted a comprehensive pharmacophore-based inhibitor screening and biochemical and biophysical examinations to identify, characterize, and validate potential inhibitors targeting the response regulators PhoP and MtrA of mycobacteria. The constructed pharmacophore model Phar-PR-n4 identified effective inhibitors of formation of the PhoP-DNA complex: ST132 (IC50 = 29 ± 1.6 µM) and ST166 (IC50 = 18 ± 1.3 µM). ST166 (KD = 18.4 ± 4.3 μM) and ST132 (KD = 14.5 ± 0.1 μM) strongly targeted PhoP in a slow-on, slow-off manner. The inhibitory potency and binding affinity of ST166 and ST132 for MtrAC were comparable to those of PhoP. Structural analyses and molecular dynamics simulations revealed that ST166 and ST132 mainly interact with the α8-helix and C-terminal β-hairpin of PhoP, with functionally essential residue hotspots for structure-based inhibitor optimization. Moreover, ST166 has in vitro antibacterial activity against Macrobacterium marinum. Thus, ST166, with its characteristic 1,2,5,6-tetrathiocane and terminal sulphonic groups, has excellent potential as a candidate for the development of novel antimicrobial agents to combat pathogenic mycobacteria.

Selenite selectively kills lung fibroblasts to treat bleomycin-induced pulmonary fibrosis

BACKGROUND

Interstitial lung disease (ILD) treatment is a critical unmet need. Selenium is an essential trace element for human life and an antioxidant that activates glutathione, but the gap between its necessity and its toxicity is small and requires special attention. Whether selenium can be used in the treatment of ILD remains unclear.

METHODS

We investigated the prophylactic and therapeutic effects of selenite, a selenium derivative, in ILD using a murine model of bleomycin-induced idiopathic pulmonary fibrosis (IPF). We further elucidated the underlying mechanism using in vitro cell models and examined their relevance in human tissue specimens. The therapeutic effect of selenite in bleomycin-administered mice was assessed by respiratory function and histochemical changes. Selenite-induced apoptosis and reactive oxygen species (ROS) production in murine lung fibroblasts were measured.

RESULTS

Selenite, administered 1 day (inflammation phase) or 8 days (fibrotic phase) after bleomycin, prevented and treated deterioration of lung function and pulmonary fibrosis in mice. Mechanistically, selenite inhibited the proliferation and induced apoptosis of murine lung fibroblasts after bleomycin treatment both in vitro and in vivo. In addition, selenite upregulated glutathione reductase (GR) and thioredoxin reductase (TrxR) in murine lung fibroblasts, but not in lung epithelial cells, upon bleomycin treatment. GR and TrxR inhibition eliminates the therapeutic effects of selenite. Furthermore, we found that GR and TrxR were upregulated in the human lung fibroblasts of IPF patient samples.

CONCLUSIONS

Selenite induces ROS production and apoptosis in murine lung fibroblasts through GR and TrxR upregulation, thereby providing a therapeutic effect in bleomycin-induced IPF.

Structure-Guided Discovery of PD-1/PD-L1 Interaction Inhibitors: Peptide Design, Screening, and Optimization via Computation-Aided Phage Display Engineering

Cancer immunotherapy harnesses the immune system to combat tumors and has emerged as a major cancer treatment modality. The PD-1/PD-L1 immune checkpoint modulates interactions between tumor cells and T cells and has been extensively targeted in cancer immunotherapy. However, the monoclonal antibodies known to target this immune checkpoint have considerable side effects, and novel PD-1/PD-L1 inhibitors are therefore required. Herein, a peptide inhibitor to disrupt PD-1/PD-L1 interactions was designed through structure-driven phage display engineering coupled to computational modification and optimization. BetaPb, a novel peptide library constructed by using the known structure of PD-1/PD-L, was used to develop inhibitors against the immune checkpoint, and specific peptides with high affinity toward PD-1 were screened through enzyme-linked immunosorbent assays, homogeneous time-resolved fluorescence, and biolayer interferometry. A potential inhibitor, B8, was preliminarily screened through biopanning. The binding affinity of B8 toward PD-1 was confirmed through computation-aided optimization. Assessment of B8 variants (B8.1, B8.2, B8.3, B8.4, and B8.5) demonstrated their attenuation of PD-1/PD-L1 interactions. B8.4 exhibited the strongest attenuation efficiency at a half-maximal effective concentration of 0.1 μM and the strongest binding affinity to PD-1 (equilibrium dissociation constant = 0.1 μM). B8.4 outperformed the known PD-1/PD-L1 interaction inhibitor PL120131 in disrupting PD-1/PD-L1 interactions, revealing that B8.4 has remarkable potential for modification to yield an antitumor agent. This study provides valuable information for the future development of peptide-based drugs, therapeutics, and immunotherapies for cancer.

[Difference of urinary protein components and the correlation between urinary protein quantification and glomerular filtration rate in pregnant women with pre-eclampsia]

Objective: To investigate the difference of urinary protein components in pregnant women with pre-eclampsia (PE) with different degrees of proteinuria and the correlation between 24-hour urinary protein quantification and estimated glomerular filtration rate (eGFR). Methods: Clinical data of 101 PE pregnant women who were delivered in Renji Hospital, Shanghai Jiao Tong University School of Medicine from July 2018 to June 2022 were retrospectively analyzed. According to 24-hour urinary protein quantification, they were divided into 3 groups, including 40 cases of mild proteinuria group (24-hour urinary protein quantification ≤2.0 g), 21 cases of moderate proteinuria group (2.0 g<24-hour urinary protein quantification ≤5.0 g), 40 cases of severe proteinuria group (24-hour urinary protein quantification >5.0 g). The general clinical data, urinary protein index and renal function index of PE pregnant women in 3 groups were compared. The eGFR was calculated based on age, serum creatinine (sCr), blood urea nitrogen (BUN) and serum albumin (sAlb). Correlation analysis was conducted between 24-hour urinary protein quantification and each index of eGFR. Results: (1) General clinical data: the median PE onset week (31 weeks) and delivery gestational week [(36.4±3.6) weeks] of PE pregnant women in the mild proteinuria group were later than those in the moderate proteinuria group [median PE onset: 22 weeks, delivery: (32.2±4.2) weeks] and severe proteinuria group [median PE onset: 25 weeks, delivery: (29.6±3.4) weeks]; systolic blood pressure, diastolic blood pressure, alanine aminotransferase, aspartate aminotransferase levels and the incidence of fetal growth restriction were lower than those in the moderate and severe proteinuria groups; median newborn birth weight (3 150 g) was higher than those in the moderate proteinuria group (1 305 g) and the severe proteinuria group (1 042 g), respectively. The differences were statistically significant (all P<0.05). (2) Urinary protein index: the 24-hour urinary protein quantification, urinary microalbumin (mAlb) and urinary transferrin (TRF) levels of PE pregnant women in the mild proteinuria group, moderate proteinuria group and severe proteinuria group were increased successively, and the differences were statistically significant (all P<0.05). The median urinary α1-microglobulin (α1-MG) level of PE pregnant women in the severe proteinuria group (50 mg/L) was significantly higher than those in the mild proteinuria group (17 mg/L) and moderate proteinuria group (22 mg/L; all P<0.05), but there was no significant difference between the mild proteinuria group and the moderate proteinuria group (P>0.05). There was no significant difference in the median urinary β2-microglobulin (β2-MG) level among the 3 groups (P=0.632). (3) Renal function index: sAlb and eGFR of PE pregnant women in the mild proteinuria group, moderate proteinuria group and severe proteinuria group were successively decreased, and BUN was successively increased, respectively, and the differences were statistically significant (all P<0.05). The sCr level of PE pregnant women in the severe proteinuria group was significantly higher than those in the mild proteinuria group and the moderate proteinuria group (all P<0.05), but there was no significant difference between the mild proteinuria group and the moderate proteinuria group (P>0.05). (4) Correlation analysis: the 24-hour urinary protein quantification of PE pregnant women was significantly negatively correlated with eGFR (r=-0.645, P<0.001), and was correlated with the variables sAlb (r=-0.549, P<0.001), sCr (r=0.582, P<0.001) and BUN (r=-0.657, P<0.001) in the eGFR calculation formula. The 24-hour urinary protein quantification were significantly negatively correlated with the gestational weeks of PE onset, gestational weeks of termination of pregnancy and newborn birth weight (all P<0.05). Conclusions: The protein composition in the urine of PE pregnant women with different degrees of proteinuria is not different, but the protein level is significantly different. There is a significant negative correlation between the increase of 24-hour urinary protein quantification and the decrease of eGFR.

[Regional analysis of high risk factors of hypertensive disorders in pregnancy with organ or system impairment]

Objective: To explore the influencing factors of pregnancy-induced hypertensive disorders in pregnancy (HDP) with organ or system impairment in pregnant women, and to analyze and compare the differences of HDP subtypes in different regions of China. Methods: A total of 27 680 pregnant women with HDP with complete data from 161 hospitals in 24 provinces, autonomous regions and municipalities were retrospectively collected from January 1, 2018 to December 31, 2018. According to their clinical manifestations, they were divided into hypertension group [a total of 10 308 cases, including 8 250 cases of gestational hypertension (GH), 2 058 cases of chronic hypertension during pregnancy] and hypertension with organ or system impairment group [17 372 cases, including 14 590 cases of pre-eclampsia (PE), 137 cases of eclampsia, 2 645 cases of chronic hypertension with PE]. The subtype distribution of HDP in East China (6 136 cases), North China (4 821 cases), Central China (3 502 cases), South China (8 371 cases), Northeast China (1 456 cases), Southwest China (2 158 cases) and Northwest China (1 236 cases) were analyzed. By comparing the differences of HDP subtypes and related risk factors in different regions, regional analysis of the risk factors of HDP pregnant women with organ or system impairment was conducted. Results: (1) The proportions of HDP pregnant women with organ or system impairment in Northeast China (79.05%, 1 151/1 456), Central China (68.42%, 2 396/3 502) and Northwest China (69.34%, 857/1 236) were higher than the national average (62.76%, 17 372/27 680); the proportions in North China (59.18%, 2 853/4 821), East China (60.85%, 3 734/6 136) and South China (59.56%, 4 986/8 371) were lower than the national average, and the differences were statistically significant (all P<0.05). (2) Univariate analysis showed that the proportions of primiparas, non-Han, non-urban household registration, irregular prenatal examination and PE history in the hypertension with organ or system impairment group were higher than those in the hypertension group, and the differences were statistically significant (all P<0.05). Multivariate logistic regression analysis showed that primiparas, non-Han, non-urban household registration, irregular prenatal examination and PE history were independent risk factors for HDP pregnant women with organ or system impairment (all P<0.05). (3) Primipara: the rates of primipara in Northeast China, North China and Southwest China were higher than the national average level, while those in South China, Central China and Northwest China were lower than the national average level. Non-Han nationality: the rates of non-Han nationality in Northeast China, North China and Northwest China were higher than the national average, while those in East China, South China and Central China were lower than the national average. Non-urban household registration: the rates of non-urban household registration in Northeast China, North China, and Southwest China were lower than the national average, while those in East China, Central China were higher than the national average. Irregular prenatal examination: the rates of irregular prenatal examination in North China, South China and Southwest regions were lower than the national average level, while those in Northeast China, Central China and Northwest China were higher than the national average level. History of PE: the incidence rates of PE in Northeast China, North China, South China and Southwest China were lower than the national average level, while those in Central China and Northwest China were higher than the national average level. Conclusions: Primiparas, non-Han, non-urban household registration, irregular prenatal examination, and PE history are risk factors for HDP pregnant women with organ or system impairment. Patients in Northeast, Central and Northwest China have more risk factors, and are more likely to be accompanied by organ or system function damage. It is important to strengthen the management of pregnant women and reduce the occurrence of HDP.

[EBF1 Promotes the Sensitivity of Cervical Cancer Cells to Cisplatin via Activating FBN1 Transcription]

Cisplatin (DDP) is widely used in the chemotherapy of cervical cancer (CC), the fourth most common female malignancy worldwide. However, some patients progress to chemotherapy resistance, which leads to chemotherapy failure, tumor recurrence, and poor prognosis. Therefore, strategies to identify the regulatory mechanisms underlying CC development and increase tumor sensitivity to DDP will help improve patient survival. This research was designed to ascertain the mechanism of EBF1-dependent regulation of FBN1 which promotes chemosensitivity of CC cells. The expression of EBF1 and FBN1 was measured in CC tissues resistant or sensitive to chemotherapy and in DDP-sensitive or -resistant cells (SiHa and SiHa-DDP cells). SiHa-DDP cells were transduced with lentiviruses encoding EBF1 or FBN1 to evaluate the influence of these two proteins on cell viability, expression of MDR1 and MRP1, and cell aggressiveness. Moreover, the interaction between EBF1 and FBN1 was predicted and demonstrated. Finally, to further verify the EBF1/FB1-dependent mechanism of DDP sensitivity regulation in CC cells a xenograft mouse model of CC was established using SiHa-DDP cells transduced with lentiviruses carrying EBF1 gene and shRNA directed to FBN1 EBF1 and FBN1 showed decreased expression in CC tissues and cells, particularly in those resistant to chemotherapy. Transduction of SiHa-DDP cells with lentiviruses encoding EBF1 or FBN1 lead to decreased viability, IC50, proliferation capacity, colony formation ability, aggressiveness, and increased cell apoptosis. We have shown that EBF1 activates FBN1 transcription by binding to FBN1 promoter region. Additionally, it was revealed that FBN1 silencing reversed the promoting effect of EBF1 overexpression on chemosensitivity of CC cells in vivo. EBF1 facilitated chemosensitivity in CC cells by activating FBN1 transcription.

Rupture of a non sinus of Valsalva aneurysm during pregnancy: Case report and review of literatures

Ruptured Sinus of Valsalva aneurysms during pregnancy is rare and presents a threat both to the mother and the fetus. We report a case of ruptured nonsinus of Valsalva aneurysms in a 26-year-old woman diagnosed at 32⁺⁴ weeks of gestation. A successful elective lower-segment cesarean section was conducted under general anesthesia. A successful surgical correction of the ruptured aneurysm under cardiopulmonary bypass (CPB) was performed with patch repair after 13 days. A multidisciplinary approach with respect to the pregnant patient's diagnosis, indications, and timing of surgery is necessary in ensuring the best possible outcomes for both the mother and the child.

[A multicenter cross-sectional study of quality of life and nonsurgical treatment in patients with knee osteoarthritis]

Objective: To explore the influencing factors of health-related quality of life (HRQoL) in patients with knee osteoarthritis, and to analyze the non-surgical treatment of knee osteoarthritis. Methods: Demographic variables, treatment modalities, imaging data, and 12-item short form health survey (SF-12) scores of patients with knee osteoarthritis in orthopedic outpatient departments of five hospitals in Beijing from December 2017 to November 2018 were collected to analyze influencing factors of HRQoL and non-surgical treatment. Results: A total of 2 034 patients were included. There were 530 males (26.1%) and 1 504 females (73.9%), with a mean age of (59.17±10.22) years. In terms of physical quality of life, female patients with knee osteoarthritis had lower physical components summary (PCS) compared with male patients (β=-0.521, P=0.036); patients aged ≥64 years had lower PCS than those aged<55 years (β=-0.636, P=0.026). Patients with an education of more than 12 years had higher PCS than those with less than 10 years (β=1.063, P<0.001). Compared to patients with mild clinical symptoms, the PCS of patients with moderate clinical symptoms was lower (β=-0.860, P=0.002), while the PCS of those with severe clinical symptoms was much lower (β=-1.126, P<0.001). Patients treated with combination therapy had higher PCS than untreated patients (β=0.731, P=0.005). In terms of mental quality of life, compared to patients engaged in sedentary work, the mental components summary (MCS) of patients engaged in mild manual labor jobs was lower (β=-0.712, P=0.015); Compared to patients with a Charson comorbidity index of 0, patients with a Charlson comorbidity index ≥ 2 had lower MCS (β=-1.183, P=0.007). In the past 12 months, 648 (31.9%), 143 (7.0%), 406 (20.0%), 680 (33.4%), 343 (16.9%), 681 (33.5%), 170 (8.4%) patients had used non-steroid anti-inflammatory drugs (NSAIDs), acetaminophen, glucosamine/chondroitin formulations, physical therapy, articular cavity puncture injection, traditional Chinese medicine treatment and exercise therapy, respectively. Total of 451 patients (22.2%) received monotherapy and 889 patients (43.7%) received combination therapy. Conclusions: The major non-surgical treatment methods for patients with knee osteoarthritis in Beijing are NSAIDs, physiotherapy and traditional Chinese medicine. Combination therapy is used more frequently than monotherapy. Physical quality of life is related to gender, age, education, severity of symptoms and treatment, while mental quality of life is related to occupational labor and comorbidities.

[Bioinformatics analysis of differently expressed genes in osteoblastic sarcoma and screening of key genes]

Objective: To screen the different expressed genes between osteosarcoma and normal osteoblasts, and find the key genes for the occurrence and development of osteosarcoma. Methods: The gene expression dataset GSE33382 of normal osteoblasts and osteosarcoma was obtained from Gene Expression Omnibus (GEO) database. The different expressed genes between normal osteoblasts and osteosarcoma were screened by limma package of R language, and the different expressed genes were analyzed by Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis. The protein interaction network was constructed by the String database, and the network modules in the interaction network were screened by the molecular complex detection (MCODE) plug-in of Cytoscape software. The different expressed genes contained in the first three main modules screened by MCODE were analyzed by gene ontology (GO) using the BiNGO module of Cytoscape software. The MCC algorithm was used to screen the top 10 key genes in the protein interaction network. The gene expression and survival dataset GSE39055 of osteosarcoma was obtained from GEO database, and the survival analysis was performed by Kaplan-Meier method. The data of 48 patients with osteosarcoma treated in the First Affiliated Hospital of Fujian Medical University from January 2005 to December 2015 were selected for verification. The expression of STC2 protein in osteosarcoma was detected by immunohistochemical method, and the survival analysis was carried out combined with the clinical data of the patients. Results: A total of 874 different expressed genes were identified from GSE33382 dataset, including 402 down-regulated genes and 472 up-regulated genes. KEGG enrichment analysis showed that different expressed genes were mainly related to p53 signal pathway, glutathione metabolism, extracellular matrix receptor interaction, cell adhesion molecules, folate tolerance, and cell senescence. The top 10 key genes in the interaction network were GAS6, IL6, RCN1, MXRA8, STC2, EVA1A, PNPLA2, CYR61, SPARCL1 and FSTL3. STC2 was related to the survival rate of patients with osteosarcoma (P<0.05). The results showed that the expression of STC2 protein was related to tumor size and Enneking stage in 48 cases of osteosarcoma. The median survival time of 25 cases with STC2 high expression was 21.4 months, and that of 23 cases with STC2 low expression was 65.4 months. The survival rate of patients with high expression of STC2 was lower than that of patients with low expression of STC2 (P<0.05). Conclusions: Bioinformatics analysis can effectively screen the different expressed genes between osteosarcoma and normal osteoblasts. STC2 is one of the important predictors for the prognosis of osteosarcoma.

Esophageal Cancer Stem-like Cells Resist Ferroptosis-Induced Cell Death by Active Hsp27-GPX4 Pathway

Cancer stem cells (CSCs), a subpopulation of cancer cells responsible for tumor initiation and treatment failure, are more susceptible to ferroptosis-inducing agents than bulk cancer cells. However, regulatory pathways controlling ferroptosis, which can selectively induce CSC death, are not fully understood. Here, we demonstrate that the CSCs of esophageal squamous carcinoma cells enriched by spheroid culture have increased intracellular iron levels and lipid peroxidation, thereby increasing exposure to several products of lipid peroxidation, such as MDA and 4-HNE. However, CSCs do not reduce cell viability until glutathione is depleted by erastin treatment. Mechanistic studies revealed that damage from elevated lipid peroxidation is avoided through the activation of Hsp27, which upregulates GPX4 and thereby rescues CSCs from ferroptosis-induced cell death. Our results also revealed a correlation between phospho-Hsp27 and GPX4 expression levels and poor prognosis in patients with esophageal cancer. Together, these data indicate that targeting Hsp27 or GPX4 to block this intrinsic protective mechanism against ferroptosis is a potential treatment strategy for eradicating CSC in esophageal squamous cell carcinoma.

[Comparative analysis of high risk factors between early-onset pre-eclampsia and late-onset pre-eclampsia]

Objective: To explore the difference of high-risk factors between early-onset and late-onset pre-eclampsia, and to further understand high-risk factors of pre-eclampsia. Methods: Clinical data of pre-eclampsia pregnant women in 160 medical institutions in China in 2018 were retrospectively analyzed, including 8 031 cases of early-onset pre-eclampsia and 12 969 cases of late-onset pre-eclampsia. The proportion of high-risk factors, different body mass index (BMI) and age stratification between early-onset group and late-onset group were compared. Results: (1) Univariate analysis of high-risk factors: the proportions of high-risk factors in early-onset group and late-onset group were compared, and the differences were statistically significant (all P<0.05). Among them, the proportions of primipara and multiple pregnancy in early-onset group were lower than those in late-onset group, while the proportions of pregnant women with advanced age, irregular antenatal examination, obesity, family history of hypertension, pre-eclampsia, diabetes, kidney diseases, immune system diseases and assisted reproductive technology were higher than those in late-onset group. (2) Hierarchical analysis of BMI: the proportion of pregnant women with BMI≥24 kg/m² in early-onset group [48.2% (2 828/5 872) vs 45.5% (4 177/9 181), respectively; P=0.001] and the proportion of pregnant women with BMI ≥28 kg/m² in early-onset group [19.5% (1 143/5 872) vs 18.0% (1 656/9 181), respectively; P=0.028] were significantly higher than those in late-onset group. (3) Age stratification analysis: the proportion of pregnant women aged 35-39 years in the early-onset group [21.8% (1 748/8 023) vs 17.5% (2 110/12 068), respectively; P<0.01], the proportion of pregnant women 40-44 years old [6.8% (544/8 023) vs 5.4% (648/12 068), respectively; P<0.01], and the proportion of pregnant women ≥45 years old [0.7% (58/8 023) vs 0.5% (57/12 068), respectively; P=0.021] were significantly higher than those in the late-onset group. (4) Multivariate analysis: advanced age (≥35 years old), multiple pregnancy, irregular antenatal examination or transfer from other hospitals, family history of hypertension (including paternal, maternal and parental lines), previous history of pre-eclampsia, kidney diseases, immune system diseases (systemic lupus erythematosus, antiphospholipid antibody syndrome) and assisted reproductive technology pregnancy were the risk factors affecting the severity of pre-eclampsia (all P<0.05). Conclusion: Pregnant women with high risk factors such as age ≥35 years old, BMI ≥24 kg/m² before pregnancy, family history of hypertension, history of pre-eclampsia, chronic kidney diseases, immune diseases (mainly including systemic lupus erythematosus and antiphospholipid syndrome) and assisted reproductive technology are more likely to have early-onset pre-eclampsia.

Risk Factors for Maternal and Perinatal Complications during Pregnancy among Women with Tetralogy of Fallot

Background

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease during pregnancy. Studies of risk factors are of great significance to maternal and fetal outcomes in patients with TOF.

Aims

To identify predictive risk factors for maternal and perinatal complications in women with TOF.

Subjects and Methods

78 patients with TOF who delivered at Shanghai Obstetrical Cardiology Intensive Care Center between January 1993 and December 2017 were retrospective reviewed. A logistic regression model was used to identify risk factors for maternal and perinatal complications.

Results

There was no maternal death, five patients developed cardiac failure, sustained arrhythmias requiring treatments were recorded among 2 patients. Factors identified for maternal complications included previous cardiac events and oxygen saturation <90%. Oxygen saturation <90% was found to be independent predictor of maternal cardiac complications (RR = 21.455, 95%CI 2.186-210.572, P = 0.009). The perinatal survival rate was 87.18%, there were 52 term deliveries (66.67%). Perinatal poor outcomes include 9 therapeutic abortions (11.54%), 1 neonatal death (1.28%), 16 premature births (20.51%), 18 small for gestational age children (23.08%), 3 neonatal asphyxia (3.85%), and 3 neonatal cardiac malformations (3.85%). Factors identified for perinatal complications included without cardiac surgery, higher hemoglobin values, higher hematocrit values, oxygen saturation <90%, right ventricular hypertrophy, pulmonary stenosis, ventricular septal defect, and pulmonary hypertension. Oxygen saturation <90% was found to be independent predictor of perinatal complications (RR = 8.270, 95%CI 1.374-49.790, P = 0.021).

Conclusions

Oxygen saturation <90% is associated with maternal and perinatal risks. Women with TOF whose oxygen saturation <90% are not recommended for pregnancy because of high maternal and perinatal complications.

[Energy metabolism characteristic with risk of secondary bacterial infection in patients with hepatitis B virus-related chronic liver disease]

Objective: To investigate and analyze the energy metabolism characteristics and the correlation between energy metabolism and the risk of secondary bacterial infection in patients with hepatitis B virus-related chronic liver disease (HBV-CLD). Methods: Data of 183 cases admitted to the Mengchao Hepatobiliary Hospital of Fujian Medical University from November 2017 to November 2020 were retrospectively analyzed. 79 cases of chronic hepatitis B, 51 cases of hepatitis B-related liver cirrhosis, and 53 cases of hepatitis B-related liver failure were collected. Among them patients with liver failure and decompensated liver cirrhosis were defined as severe liver disease group. The Quark RMR indirect calorimetry (COSMED Corporation, Italy) was used to exam the patients' energy metabolism condition, and the incidences of secondary bacterial infection of the patients during hospitalization were recorded. Shapiro-Wilk test and normal QQ plot were used to analyze the normal distribution of continuous variable data, which was consistent with the normal distribution and was described by mean ± standard deviation. In addition, if it did not conform to the normal distribution, the median and interquartile distance were used to describe it. Levene's test was used to test the homogeneity of variance of the data, which was consistent with the normal distribution. The t-test was used to compare the means of the two groups of samples. One-way analysis of variance was used to compare the mean values of the three groups of samples, and then the Tukey's test was used to compare the two groups. If the variance was uneven or did not conform to the normal distribution, the Wilcoxon rank sum test was used to compare the differences between the two groups. Kruskal-Wallis test (H test) was used to compare the differences between the three groups of samples, and then the Dunnett's test (Z test) was used for comparison between the two groups. Categorical variable data were analyzed using chi-square test. Logistic regression analysis was used to screen independent risk factors, and the criteria for variable inclusion (P < 0.05). Results: The respiratory entropy (RQ) and non-protein respiratory entropy (npRQ) of the three groups had statistically significant difference (P < 0.05). Among them, the RQ and npRQ of the chronic hepatitis B group were higher than hepatitis B-related liver cirrhosis group and hepatitis B-related liver failure group. There were statistically significant differences in fat oxidation rate (FAT%) and carbohydrate oxidation rate (CHO%) between the three groups (P < 0.05). Compared with hepatitis B-related liver cirrhosis group and hepatitis B-related liver failure group, chronic hepatitis B group (P < 0.05) had lower FAT% and higher CHO%. There were no statistically significant differences in the measured and predicted resting energy expenditure and protein oxidation rate (PRO%) between the three groups. The incidence of secondary bacterial infection in patients with severe liver disease was 48.39% (45/93). Compared with the non-infected group, the RQ and npRQ values ​​of the infected group were significantly decreased (P < 0.05), while FAT% was significantly increased (P < 0.05). Logistic regression analysis showed that glutamyltransferase, cholesterol, and npRQ were independent risk factors for secondary bacterial infections in patients with severe liver disease. Glutamyltransferase elevation, and cholesterol and npRQ depletion had suggested an increased risk of secondary bacterial infection. Subgroup analysis of patients with hepatitis B-related liver failure also showed that compared with non-infected group, RQ value and npRQ value of secondary bacterial infection group were significantly decreased (P < 0.05), while FAT% was significantly increased (P < 0.05). Conclusion: Patients with hepatitis B virus-related chronic liver disease generally have abnormal energy metabolism. Low RQ, npRQ, CHO% and high FAT% are related to the severity of the disease; while npRQ reduction is related to the risk of secondary bacterial infection in patients with severe liver disease, and thus can be used as a clinical prognostic indicator.

[Effects of neuromuscular exercise therapy on the joint stability of patients with knee osteoarthritis]

Objective: To evaluate the effects of neuromuscular exercise therapy on joint stability of knee osteoarthritis (OA) patients. Methods: One hundred and ten patients with knee OA were enrolled in this ongoing prospective cohort study at Arthritis Clinic and Research Center, Peking University People's Hospital from September 2017 to October 2018. The treatment consisted of six-week neuromuscular exercise therapy. The participants were followed up at 6 weeks and 3 months after the therapy. The stability of the joint was evaluated by the index of knee joint stability (IKJS), which was extracted by a novel knee-aiming task combined with the multiscale entropy (MSE) analysis of the complexity of the light spot trajectories. The secondary outcomes were pain on the visual analogue scale (VAS, 0-100), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), quality of life on the Euro-quality of life-5 Dimensional (EQ-5D) VAS form, 30-second chair stand test and 40-meter walk test. One-way repeated measures ANOVA analysis was applied to compare the outcomes at baseline and 6 weeks and 3 months. Pearson partial analysis was used to investigate the correlation between the IKJS and the Kellgren-Lawrence (K/L) rate, pain and knee function. Results: Ninety-six participants ((65±8) years, 21 males, 75 females) completed 3-month follow-up. There was a significant improvement in IKJS at the 6-week visit compared with that at baseline (0.369, 95% confidence interval (CI) 0.241-0.496, P<0.001). The IKJS dropped at 3-month visit compared with 6-week visit, but was still better than that at baseline (0.178, 95%CI: 0.042-0.314, P=0.008). The correlation between IKJS and K/L rate, severity of pain, WOMAC or knee function was not significant (r=-0.131, -0.059, -0.231, 0.124, all P>0.05). There was improvement in pain VAS, WOMAC, EQ-5D-VAS, 30-second chair stand test and 40-meter walk test at 6 weeks and 3 months (all P<0.05). Conclusion: The neuromuscular exercise therapy is effective in improving the joint stability of the knee OA patients. However, the effect gradually diminished over time. In addition, neuromuscular exercise can help relieve pain, improve the function and quality of life in patients with knee OA.

Upregulation of ACE2 and TMPRSS2 by particulate matter and idiopathic pulmonary fibrosis: a potential role in severe COVID-19

BACKGROUND

Air pollution exposure and idiopathic pulmonary fibrosis (IPF) cause a poor prognosis after SARS-CoV-2 infection, but the underlying mechanisms are not well explored. Angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) are the keys to the entry of SARS-CoV-2. We therefore hypothesized that air pollution exposure and IPF may increase the expression of ACE2 and TMPRSS2 in the lung alveolar region. We measured their expression levels in lung tissues of control non-IPF and IPF patients, and used murine animal models to study the deterioration of IPF caused by particulate matter (PM) and the molecular pathways involved in the expression of ACE2 and TMPRSS2.

RESULTS

In non-IPF patients, cells expressing ACE2 and TMPRSS2 were limited to human alveolar cells. ACE2 and TMPRSS2 were largely upregulated in IPF patients, and were co-expressed by fibroblast specific protein 1 (FSP-1) + lung fibroblasts in human pulmonary fibrotic tissue. In animal models, PM exposure increased the severity of bleomycin-induced pulmonary fibrosis. ACE2 and TMPRSS2 were also expressed in FSP-1+ lung fibroblasts in bleomycin-induced pulmonary fibrosis, and when combined with PM exposure, they were further upregulated. The severity of pulmonary fibrosis and the expression of ACE2 and TMPRSS2 caused by PM exposure were blocked by deletion of KC, a murine homologue of IL-8, or treatment with reparixin, an inhibitor of IL-8 receptors CXCR1/2.

CONCLUSIONS

These data suggested that risk of SARS-CoV-2 infection and COVID-19 disease severity increased by air pollution exposure and underlying IPF. It can be mediated through upregulating ACE2 and TMPRSS2 in pulmonary fibroblasts, and prevented by blocking the IL-8/CXCR1/2 pathway.

[Survey of related factors of maternal venous thromboembolism in nine hospitals of China]

Objective: To investigate and analyze disease status and risk factors of venous thromboembolism (VTE) during pregnancy and puerperium in our country. Methods: Clinical datas were collected from 575 patients diagnosed with VTE during pregnancy and puerperium and hospitalized in nine medical institutions in our country from January 1, 2015 to November 30, 2019, and retrospectively analyzed it's disease status and risk factors. Results: (1) The proportion of VTE in pregnancy and puerperium was 50.6% (291/575) and 49.4% (284/575), respectively. Four patients died, the mortality rate was 0.7% (4/575). The cause of death was pulmonary embolism. (2) The location of VTE during pregnancy and puerperium was mainly in the lower limb vascular (76.2%, 438/575), followed by pulmonary vessels (7.1%, 41/575). (3) In the risk factors of VTE, cesarean section accounted for 32.3% (186/575), maternal advance age accounted for 27.7% (159/575), braking or hospitalization during pregnancy accounted for 13.6% (78/575), other risk factors accounted for more than 5% were previous VTE, obesity, preterm birth, assistant reproductive technology conception and so on, pre-eclampsia and multiple pregnancy accounted for 4.9% (28/575) respectively. In addition, some patients with VTE did not have any of the above risk factors, and the incidence rate was as high as 23.1% (133/575). Conclusions: The occurrence of VTE during pregnancy and puerperium is related to multiple risk factors, and could lead to matemal death, It is very necessary to screen VTE risk factors for all pregnant women, to make corresponding prevention and control measures.

Involvement of collagen XVII in pluripotency gene expression and metabolic reprogramming of lung cancer stem cells

BACKGROUND

Recent advancements in cancer biology field suggest that glucose metabolism is a potential target for cancer treatment. However, little if anything is known about the metabolic profile of cancer stem cells (CSCs) and the related underlying mechanisms.

METHODS

The metabolic phenotype in lung CSC was first investigated. The role of collagen XVII, a putative stem cell or CSC candidate marker, in regulating metabolic reprogramming in lung CSC was subsequently studied. Through screening the genes involved in glycolysis, we identified the downstream targets of collagen XVII that were involved in metabolic reprogramming of lung CSCs. Collagen XVII and its downstream targets were then used to predict the prognosis of lung cancer patients.

RESULTS

We showed that an aberrant upregulation of glycolysis and oxidative phosphorylation in lung CSCs is associated with the maintenance of CSC-like features, since blocking glycolysis and oxidative phosphorylation reduces sphere formation, chemoresistance, and tumorigenicity. We also showed that the Oct4-hexokinase 2 (HK2) pathway activated by collagen XVII-laminin-332 through FAK-PI3K/AKT-GSB3β/β-catenin activation induced the upregulation of glycolysis and maintenance of CSC-like features. Finally, we showed that collagen XVII, Oct4, and HK2 could be valuable markers to predict the prognosis of lung cancer patients.

CONCULSIONS

These data suggest the Oct4-HK2 pathway regulated by collagen XVII plays an important role in metabolic reprogramming and maintenance of CSC-like features in lung CSCs, which may aid in the development of new strategies in cancer treatment.

[Analysis of maternal deaths with cardiovascular diseases in Shanghai obstetric heart disease intensive care unit within twenty-six years]

Objective: To analyze risk factors, cardiovascular complications, time of death, gestational age of delivery and offspring outcomes in the maternal deaths with cardiovascular diseases (CVD). Methods: Totally 4 112 cases of pregnant women with CVD in Shanghai obstetric heart disease intensive care unit within 26 years (from January 1993 to December 2018) were collected, and 20 maternal deaths within these cases were analyzed retrospectively. Results: (1) Among the 20 deaths, structural heart diseases accounted for 90% (18/20), pregnancy induced heart diseases was 10% (2/20) while there was no dysfunctional heart disease. The mortality of pregnant women with CVD was 0.486% (20/4 112). (2) The following risk factors were common in these women, getting pregnant without counselling (95%, 19/20) , New York Heart Association classⅢ or Ⅳcardiac function (70%, 14/20), complicated with pulmonary hypertension (75%, 15/20) and prior heart events (60%, 12/20). And 85% (17/20) deaths occurred in puerperium, 15% (3/20) occurred before labor,while no death occurred during labor. And 65% (13/20) deaths died due to heart failure, 20% (4/20) deaths were due to pulmonary hypertension crisis, 5% (1/20) died on sudden cardiac arrest, rupture of aortic dissection and sudden death, respectively. Conclusions: Women with CVD should get pregnant after strict evaluation. Pulmonary hypertension is one of the most severe contraindications to pregnancy, especially in patients with moderate to severe pulmonary hypertension. The puerperium period is a critical period that threatens the safety of these patients. Since heart failure is the most common cause of death, it is necessary to prevent and treat heart failure and to monitor heart function dynamically, especially in those with structural abnormal heart diseases. Moreover, it is also of importance to standardize antenatal care and to identify the severity of heart diseases in time.

S doped NiCo2O4 nanosheet arrays by Ar plasma: An efficient and bifunctional electrode for overall water splitting

Transition metal oxides show great potential as electrocatalysts, owing to the low cost and rich chemical states. However, the limited surface areas, low intrinsic activity and poor hydrogen evolution reaction (HER) activity greatly restrict the application for overall water splitting. Herein, we have constructed S doped NiCo₂O₄ nanosheet arrays by Ar plasma (Ar-NiCo₂O₄|S) to enhance active sites and boost catalytic kinetics. Consequently, the Ar-NiCo₂O₄|S shows the improved performances for HER and oxygen evolution reaction (OER). Further, as bifunctional electrocatalysts, Ar-NiCo₂O₄|S exhibit a voltage of 1.63 V at 10 mA cm^-2, as well as good stability.

264The long noncoding RNA H19 modulates cardiac remodeling after infarction

Noncoding RNAs account for 80% of human transcripts, but functional studies on noncoding RNAs are relatively few and limited. Long noncoding RNAs (lncRNAs) are known to have an important role in cardiac development, and lately, high-throughput RNA sequencing has been extensively utilized to profile and explore the transcriptome landscape of lncRNAs in failing hearts. These studies have revealed that lncRNAs are mostly dysregulated in failing hearts and their expression signature can discriminate failing hearts of different etiologies.

H19 is abundantly expressed in failing human hearts and its polymorphism was shown to possess a significant correlation with the risk of coronary artery diseases. In our study using murine hearts, we discovered that H19 was significantly up regulated in the heart after ischemic injury, with predominant expression in cardiac fibroblasts. This finding piqued our interest to further investigate the function of H19 in the heart.

We demonstrated that ectopic overexpression of H19 using the AAV approach led to severe cardiac fibrosis in mouse hearts following myocardial infarction. In light of this finding, we generated H19 knockout mice to further investigate the functionality of H19 and we found that cardiac fibrosis was attenuated in these mice. Altogether, these findings suggested that H19 is a fibrosis regulator during cardiac remodeling process after infarction. Due to the multiple regulatory roles of lncRNAs, we then took advantage of chromatin isolation by RNA purification (ChIRP) to identify the H19-interacting protein, YB-1. Surprisingly, mice with YB-1 knockdown displayed severe cardiac fibrosis even without injury. Furthermore, we demonstrated that YB-1 is a transcriptional suppressor of collagen 1A1. Knockout of H19 in YB-1 knockdown partially suppressed Col1a1 expression, which suggests a negative regulatory role of H19 on YB-1 towards the expression of Col1a1.

Taking into account all of these findings, we concluded that H19 mediates collagen expression in fibroblasts through the inhibition of YB-1 activity during cardiac remodeling.

[Microbiology analysis of periprothetic joint infection post total hip and knee arthroplasty of 9 centers in Beijing between 2014 and 2016]

Objective: To investigate the microbiological test, antibiotic sensitivity and surgical treatment of periprosthetic joint infection(PJI) cases in post total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients. Methods: A retrospective cross-sectional survey was conducted on 318 patients who underwent THA or TKA in 9 clinical centers in Beijing from January 2014 to December 2016.The data of microbiology, antibiotic sensitivity and surgical treatment were collected.The average age of patients was (62.3±13.1) years old (range: 21-86 years old), including 145 males and 173 females.The body mass index was (25.6±3.8) kg/m (2) (range: 15.6-38.1 kg/m(2)). Results: In total, 318 patients had microorganisms detected by periprosthetic tissue culture or synovial fluid culture, 209 cases (65.7%) had Gram-positive bacteria, 29 cases (9.1%) had Gram-negative bacteria, 10 cases (3.1%) had fungi, 3 cases (0.9%) had non-tuberculous mycobacteria, 72 cases (22.6%) were negative, 69 cases (21.7%) had methicillin-resistant bacteria. The antibiotic sensitivity results showed that the overall resistance rate of penicillin, cefuroxime, amoxicillin+clavulanic acid was 79.9%, 69.9%, and 68.1%, respectively; meropenem, vancomycin, and linezolid resistance rate was 0. For the treatment methods of hip and knee PJI, two-stage revision surgery acounted for 72.9% (108/148) and 64.1% (109/170), respectively. One-stage revision surgery accounted for 21.6% (32/148) and 7.6% (13/170), and open debridement surgery accounted for 4.7%(7/148) and 26.4% (45/170). Conclusions: Gram-positive bacteria was still the main pathogen of PJI.The methicillin-resistant bacteria and rare bacteria should be payed attention to. The Majority of hip and knee PJI cases were treated by two-stage revision surgery.

High metabolic rate and stem cell characteristics of esophageal cancer stem-like cells depend on the Hsp27-AKT-HK2 pathway

Tumor progression with chemoresistance and local recurrence is commonly happened during treatment of esophageal squamous cell carcinoma (ESCC). Cancer stem cells (CSC) may respond for tumor progression. However, there are few reports regarding metabolism of esophageal CSCs with clinical correlation. In this work, we demonstrated that ESCC cell lines in spheroid culture display CSC phenotypes, including increased ALDH activity, chemoresistance and tumor initiation, which are dependent on Hsp27 activation. Esophageal CSCs also exhibit reprogrammed metabolic features particularly higher glycolysis and oxidative phosphorylation, which are regulated via the Hsp27-AKT-HK2 pathway. Moreover, HK2 is required for maintenance of CSC phenotypes. Inhibition of CSC metabolism reduces cell growth and tumor formation. Clinically, patients who underwent surgical resection for esophageal cancer, and displayed overexpression of both Hsp27 and HK2, had the worst prognosis of all expression types. In conclusion, stem cells features and aberrant metabolic reprogramming of esophageal CSCs depend on the Hsp27-AKT-HK2 pathway. Targeting Hsp27 and HK2 could be novel therapeutic strategy for treating esophageal cancer and warrants further investigation.

[Exploration on developing the diagnosis and treatment guidelines for osteoarthritis in primary care of China]

At present, several clinical practice guidelines for osteoarthritis have been developed. Although contradictions about some recommendations are still in dispute, large number of clinical practice guidelines recommended core treatments, namely education, weight loss and exercise therapy. Thus, the diagnosis and treatment of primary osteoarthritis should focus on the above three treatments. However, we have to develop the clinical practice guidelines for osteoarthritis in primary hospital, based on the characteristics of osteoarthritis in China, the burden of disease, the health literacy of patients and the clinical decision-making of diagnosis and treatment of primary osteoarthritis in primary medical care.We suggest to formulate guidelines for the diagnosis and treatment of osteoarthritis in primary medical care to regulate primary interventions.

Case of twin pregnancy complicated by idiopathic thrombocytopenic purpura treated with intravenous immunoglobulin: Review of the literature

Idiopathic thrombocytopenic purpura (ITP) is an acquired thrombocytopenia without other clear cause of thrombocytopenia. It is not common in a singleton pregnancy and less common in twin pregnancy. We report a 33-year-old ITP pluripara whose first pregnancy was uneventful. She carried twin pregnancy, complicated by recurrent very low platelets, and gave birth to preterm twins. This patient received multiple courses of intravenous immunoglobulin (IVIG) and showed a significant platelet count improvement with IVIG therapy.

[Analysis of the difference of serum immunoglobulins, β2-microglobulin and transferrin in pre-eclampsia and pregnancies complicated with chronic kidney disease]

Objective: To observe and analyze the difference of serum immunoglobulin IgA, IgG, IgM, β2-microglobulin and transferrin in pre-eclampsia (PE) and pregnancies complicated with chronic kidney disease. Methods: Totally 46(40.0%) pregnancies with PE (PE group), 36(31.3%) pregnancies with chronic kidney disease (chronic kidney disease group) and 33(28.7%) normal pregnancies with normal blood pressure and proteinuria without any complication (control group) delivered in Renji Hospital were recruicted in this study from February 2017 to July 2017. Serum IgA, IgG, IgM, β2-microglobulin and transferrin levels were detected. Correlation tests were conducted between these indicators and blood pressure, 24 hours proteinuria value and delivery weeks. Results: (1) Comparison of general situation of pregnancies in the 3 groups: there were no significant difference in the age and child bearing history between the 3 groups (all P>0.05), while there was a significant difference in the blood pressure and deliver week (all P<0.01). There was no significant difference in 24 hours proteinuria values between PE group and chronic kidney disease group (Z=-0.187, P=0.852). (2) Comparison of serum immunoglobulin, β2-microglobulin and transferrin levels in pregnant women with three groups: serum IgA level in chronic kidney disease group was significantly higher than those in PE and control groups [(2.4±0.9) vs (1.8±0.9) vs (1.6±0.6) g/L; F=9.959, P<0.01]. The serum IgG and IgM values had no significant difference between the 3 groups (all P>0.05). Serum β2-microglobulin in chronic kidney disease group was significantly higher than those in PE and control groups [(4.0±2.6) vs (2.7±0.7) vs (2.0±0.5) mg/L; F=15.892, P<0.01]. Serum transferrin in chronic kidney disease group was significantly lower than those in PE and control groups [(3.0±0.8) vs (3.7±1.1) vs (3.6±0.6) g/L; F=6.284, P<0.01]. (3) The correlation between serum immunoglobulin, β2-microglobulin, transferrin and blood pressure, proteinuria value and delivery weeks in PE group: the blood pressure level was not correlated with serum IgA, β2-microglobulin and transferrin values in PE group (all P> 0.05). So, 24 hours proteinuria value was positively correlated with β2-microglobulin (r=0.557, P<0.01), which was negatively correlated with transferrin (r=-0.442, P<0.01) and was not correlated with IgA(r=0.089, P=0.556). There was a negative correlation between delivery weeks and β2-microglobulin (r=-0.328, P=0.026), and positive correlation with transferrin (r=0.315, P=0.035) and no correlation with IgA (r=-0.169, P=0.260). (4) The correlation between serum immunoglobulin, β2-microglobulin, transferrin and blood pressure, proteinuria value and delivery weeks in chronic kidney disease group: the blood pressure level was positively correlated with β2- microglobulin (systolic pressure: r=0.598, P<0.01; diastolic pressure:r=0.557, P<0.01), which was not correlated with IgA and transferrin in chronic kidney disease group (all P>0.05). So, 24 hours proteinuria value was positively correlated with β2-microglobulin and IgA (r=0.568, r=0.330, both P<0.05), and not correlated with transferrin (r=0.255, P=0.133). Delivery weeks had a negative correlation with β2-microglobulin (r=-0.574, P<0.01), while it had a positive correlation with transferrin (r=0.369, P=0.027). No correlation was found between delivery weeks and IgA values (r=-0.257, P=0.131). Conclusion: The serum levels of IgA, β2-microglobulin and transferrin in PE and pregnancies with chronic kidney disease are significantly different, which may provide clinical value for the diagnosis of PE and pregnancies with chronic kidney disease in future.

[Influence of different inner dressings in negative-pressure wound therapy on escharectomy wound of full-thickness burn rabbits]

Objective: To explore the influence of different inner dressings in negative-pressure wound therapy (NPWT) on escharectomy wound of full-thickness burn rabbits. Methods: Eighteen Japanese white rabbits were inflicted with full-thickness burn on unilateral back. They were divided into polymer dressing group (PD), biological dressing group (BD), and silver biological dressing group (SBD), according to the random number table, with 6 rabbits in each group. On 3 days post burn, the wounds were performed with escharectomy, and then wounds of rabbits in group PD were covered with polyurethane foam. Wounds of rabbits in group BD were covered with porcine acellular dermal matrix (ADM) and wounds of rabbits in group SBD were covered with silver porcine ADM. Then continuous NPWT was performed on rabbits of the three groups for 7 days. Immediately after surgery and on post surgery day (PSD) 7, general observation of wound was conducted and tissue around the wound was harvested for determination of dry to wet weight ratio. The content of bacteria was counted and the content of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and IL-6 in wound was determined by enzyme-linked immunosorbent assay. Fibroblasts in wound were counted after Masson staining and number of microvessels was counted after CD31 antibody immunohistochemical staining. Data were processed with analysis of variance for repeated measurement, LSD-t test, paired samples t test, and Bonferroni correction. Results: (1) Immediately after surgery, there was no granulation tissue in basal wound of rabbits in the three groups, with rich blood supply and obvious edema. On PSD 7, much granulation tissue was found in basal wound of rabbits in the three groups, with no or mild edema and no obvious redness and swelling in wound edge. (2) There were no significant differences in dry to wet weight ratios of tissue around the wound among and within the three groups immediately after surgery and on PSD 7 (with F values respectively 0.70 and 0.09, t values from 0.17 to 0.52, P values above 0.05). (3) Immediately after surgery, the content of bacteria in wounds of rabbits in groups PD, BD, and SBD was respectively (603.0±146.0) ×10(4,) (573.0±63.0) ×10(4,) and (590.0±100.0)×10(4) colony-forming unit (CFU)/g, with no significant difference among them (F=0.13, P>0.05). On PSD 7, the content of bacteria in wounds of rabbits in groups PD, BD, and SBD were respectively (5.4±0.8) ×10(4,) (4.6±0.9) ×10(4,) and (3.5±0.9)×10(4) CFU/g. Among them, the content of bacteria in wounds of rabbits in group SBD was lower than that in groups PD and BD, respectively (with t values respectively 3.78 and 2.29, P<0.05 or P<0.01). The content of bacteria in wounds of rabbits in the three groups on PSD 7 was decreased compared with that immediately after surgery (with t values from 10.05 to 21.81, P values below 0.01). (4) There was no significant difference in content of TNF-α, IL-1β, and IL-6 in wounds of rabbits in the three groups immediately after surgery and on PSD 7 (with F values from 0.10 to 1.89, P values above 0.05). The content of TNF-α in wounds of rabbits in the three groups on PSD 7 was significantly higher than that immediately after surgery (with t values from 2.93 to 5.01, P<0.05 or P<0.01). (5) There was no significant difference in amount of fibroblasts in wounds of rabbits in the three groups immediately after surgery and on PSD 7 (with F values respectively 0.01 and 0.81, P values above 0.05). The amount of fibroblasts in wounds of rabbits in the three groups on PSD 7 was larger than that immediately after surgery (with t values from 4.78 to 11.58, P values below 0.01). (6) There was no significant difference in number of microvessels in wounds of rabbits in the three groups immediately after surgery and on PSD 7 (with F values respectively 2.42 and 2.49, P values above 0.05). The number of microvessels in wounds of rabbits in the three groups on PSD 7 was larger than that immediately after surgery (with t values from 7.17 to 11.14, P values below 0.01). Conclusions: SBD is better at inhibiting the growth of bacteria. PD, BD, and SBD have almost the same effects on reducing tissue edema and inflammatory reaction, and on promoting the accumulation of collagen fibers and tissue vascularization.

[Efficacy and safety of oseltamivir in children with suspected influenza: a multicenter randomized open-label trial]

Objective: To evaluate the efficacy and safety of oseltamivir in the treatment of suspected influenza in children. Method: A multicenter, randomized and open-label trial was conducted among 229 individuals with suspected influenza which were collected from the clinic of 5 hospitals in Guangdong province (Guangzhou Women and Children's Medical Center, Shenzhen Baoan District Maternity and Child Care Service Center, the Second Affiliated Hospital of Shantou University Medical College, Dongguan Maternity and Child Care Service Centre, Yuexiu District Children's Hospital of Guangzhou) from April to July 2015. They were randomized either to oseltamivir group (oseltamivir 30-75 mg, twice daily for 5 days) or control group who were given symptom relief medicines for 5 days. Result: No significant difference was found between two groups in influenza symptoms of the patients before the treatment(P>0.05). Altogether 229 individuals (114 in oseltamivir group, 115 in control group) were analyzed for efficacy, in which 73 individuals (42 oseltamivir, 31 control), 31.9%, were identified as influenza-infected through laboratory test. No significant difference was found between the two groups in the duration of fever although shortened. In the 229 individuals , the cumulative alleviation proportion between oseltamivir and control group was not significantly different (P>0.05): the median duration of illness was 69.9 hours (95% CI 65.3-91.5) in oseltamivir group and 75.4 hours (95%CI 63.9-91. 7) in control group; the median duration of fever was 40.4 hours (95%CI 31.5-53.4) in oseltamivir group and 44.0 hours (95%CI 33.2-50.0) in control group. In the 73 individuals, the cumulative alleviation proportion between oseltamivir and control group was significantly different (P<0.05). The median duration of illness was 61.2 hours (95%CI 48.0-121. 0) in oseltamivir group, being significantly shorter than that of 116.0 hours (95%CI 91.5-175.0) in control group. But it was not significantly different that the median duration of fever was 32.8 hours (95%CI 24.0-47.0 ) in oseltamivir group and 55.8 hours (95%CI 43.6-78.3 ) in control group (P>0.05). And the median duration of fever in 60 individuals (38 oseltamivir, 22 control) was significantly different between two groups(P<0.05), who had finished a course of taking oseltamivir in the 73 individuals, 34.8 hours (95%CI 24.0-48.5 ) in oseltamivir group being significantly shorter than that of 53.3 hours (95%CI 43.6-104.0 ) in control group. There was certain difference in side effects rate between the two groups (oseltamivir 10%, control 2%, P<0.05). The main side-effects were gastrointestinal symptoms (stomachache, diarrhea, poor appetite, vomiting). Conclusion: The duration of illness and fever in suspected influenza patients treated with oseltamivir was shorter than those in the patients treated with no oseltamivir, the difference was not statistically significant, when 31.9% was confirmed with positive result of virus test in suspected influenza in children. But in these patients with positive result of virus test, the duration of illness was significantly shortened with treatment with oseltamivir as compared with no treatment with oseltamivir, and it would be better if full oseltamivir course was completed for reducing the duration of fever. Oseltamivir treatment was safe with mild side effects.

[Progress in methodological characteristics of clinical practice guideline for osteoarthritis]

At present, several clinical practice guidelines for the treatment of osteoarthritis have been developed by institutes or societies. The ultimate purpose of developing clinical practice guidelines is to formulate the process in the treatment of osteoarthritis effectively. However, the methodologies used in developing clinical practice guidelines may place an influence on the transformation and application of that in treating osteoarthritis. The present study summarized the methodological features of individual clinical practice guideline and presented the tools for quality evaluation of clinical practice guideline. The limitations of current osteoarthritis guidelines of China are also indicated. The review article might help relevant institutions improve the quality in developing guide and clinical transformation.

Medium-term results of ceramic-on-polyethylene Zweymüller-Plus total hip arthroplasty

INTRODUCTION

The need for better durability and longevity in total hip arthroplasty for patients with various hip joint diseases remains a challenge. This study aimed to obtain medium-term results at a follow-up of >10 years for Zweymüller-Plus total hip arthroplasty with ceramic-on-polyethylene bearing.

METHODS

A retrospective study was conducted to review the results after a minimum of 12.4 years of 207 consecutive total hip arthroplasties in 185 patients in Peking University People's Hospital in China using the Zweymüller SL-Plus stem in combination with the Bicon-Plus threaded cup and ceramic-on-polyethylene bearing between October 1994 and April 2000.

RESULTS

During the study period, two patients (2 hips) died and 25 patients (28 hips) were lost to follow-up. Two hips were revised for aseptic loosening of the Bicon-Plus cup. The mean clinical and radiological follow-up was 14.1 years (range, 12.4-16.5 years) for the remaining 156 patients (175 hips). The mean (standard deviation) Harris Hip score for the 175 hips increased significantly from 39.3 (3.8) preoperatively to 94.1 (2.5) postoperatively at a mean follow-up of 14.1 years (P<0.05). Focal osteolysis was observed in seven (4.0%) of 175 stems and three (1.7%) of 175 cups. The Kaplan-Meier survival with revision for any reason as the end-point was 99.03% (95% confidence interval, 95%-100%).

CONCLUSIONS

The high survival rate of the cementless Zweymüller-Plus system with ceramic-on-polyethylene bearing at mid-term follow-up makes this total hip arthroplasty system reliable for patients with various hip joint diseases.

Aspergillus awamori-fermented mung bean seed coats enhance the antioxidant and immune responses of weaned pigs

The potential benefits of Aspergillus-fermented mung bean seed coats (FMSC) for weaned pigs remain unexplored. Both in vitro and in vivo experiments were employed to evaluate the potential of FMSC supplement on the growth, antioxidant and immune responses of weaned pigs. The total polyphenols and DPPH scavenging capability of ethanol extract of FMSC exhibited a greater (p < 0.01) increase than those of pre-fermentation. With the addition of the polyphenol of FMSC extract, an increase in phagocytosis by neutrophils and proliferation of peripheral blood mononuclear cells (PBMC) were found. However, these observations were significantly inhibited (p < 0.05) in those activated cells. Next, 96 weaned pigs were allotted with a randomized complete block design into four dietary treatments, including 0 (control), 600, 1200 or 1800 mg/kg FMSC in a corn-soya bean meal basal diet for a 35-day trial. The pigs were injected with swine enzootic pneumonia (SEP) vaccines at day 3 and day 21 respectively. The results showed that dietary treatment failed to affect growth performance or serum SEP titre. The diet supplemented with 600-1800 mg/kg FMSC decreased faecal lactoferrin on day 21 and increased plasma trolox equivalent antioxidant capacity (TEAC) and erythrocytes catalase activity, as well as decreased (p < 0.01) plasma malondialdehyde (MDA) concentration on day 35. Diet supplementation of 1800 mg/kg FMSC increased phagocytosis by neutrophils and PBMC proliferation induced by pokeweed mitogen (PWM). However, the polymorphonuclear leucocytes (PMN)-positive respiratory burst cells were decreased in the supplementation of 1200 or 1800 mg/kg FMSC respectively. In addition, the serum haptoglobin concentration was decreased in the supplementation with 1200 mg/kg FMSC. Taken together, FMSC enriches polyphenols with antioxidative and immune modulated properties. After feeding FMSC, an improvement in antioxidative capability and immunocompetence was found, implying that FMSC could provide as a feed additive at optimal level 1200 mg/kg for weaned pigs.

[The fees of patients with knee osteoarthritis]

Objective: To assess the cost of illness, the current medication treatment status and health service utilization of patients with knee osteoarthritis (OA). Methods: From January 2014 to May 2015, 250 patients in Arthritis Clinic and Research Center, Peking University People's Hospital were recruited and followed up for 12 months. There were four visits during the follow-up, i. e. baseline, 1, 6 and 12 month. Data on sociodemographic variables, direct cost of illness, medication utilization and health service utilization were obtained by the questionnaire for the analyses. Results: Two hundred and twelve participants had accomplished the 12-month follow-up. The direct cost of knee OA was (8 858±5 120) yuan per year , median number was 7 020 yuan. Medical-related cost was (7 184±4 890) yuan per year , median number was 5 420 yuan; comprising 81.1% of the direct cost, whereas the non-medical related cost was( 1 674±924) yuan(RMB) per year , median number (1 239) yuan, comprising 18.9% of the direct cost. The medication cost was (5 484±3 510) yuan , median number was 4 046 yuan, accounting for the largest proportion (76.3%) of the medical-related cost. As for the medication utilization, glucosamine was most commonly prescribed (64.8%), followed by the Chinese herbals (61.2%) and NSAIDs (48.8%). The average amount of the hospital-visit per year was (11.8±4.1). Most knee OA patients (68.8%) took the tertiary care hospital as their first choice when they consulted orthopedists or physicians for OA. Conclusion: The direct cost of OA patients is considerable. OA patients may take medicine blindly and not follow the current guidelines. The prevention and treatment of OA needs to be further standardized in the future.

Collagen XVII/laminin-5 activates epithelial-to-mesenchymal transition and is associated with poor prognosis in lung cancer

Epithelial-to-mesenchymal transition (EMT) is associated with tumor metastasis and tumorigenesis in lung cancer stem-like cells (CSCs). However, the exact mechanism underlying this is not clear. We used microarray analysis to identify candidate genes responsible for EMT in spheroid and monolayer cultures of lung cancer cells. We found increased expression of a variety of adhesion molecules in CSCs. One of these molecules, Collagen XVII (Col XVII), was demonstrated to be required for maintenance of EMT phenotypes and metastasis ability in lung CSCs. We showed that Col XVII stabilized laminin-5 to activate the FAK/AKT/GSK3β pathway, thereby suppressing Snail ubiquitination-degradation. The function of Col XVII was mainly dependent on shedding by ADAM9 and ADAM10. Patients who underwent surgical resection for lung cancer, and displayed overexpression of both Col XVII and laminin-5, had the worst prognosis of all expression types. Moreover, blockage of the Col XVII/laminin-5 pathway reduced the EMT phenotypes of lung CSCs in vitro and decreased the potential of lung metastasis in vivo. Our findings suggested that targeting Col XVII and laminin-5 could be novel therapeutic strategies for treating lung cancer patients, and warrant further investigation.

[Effects on wound bed of deep burn following eschar excision with different wound management in rabbits]

OBJECTIVE

To compare the effects on wound bed of deep burn following eschar excision with different wound management in rabbits.

METHODS

Eighteen full-thickness burns models of Japanese white rabbits were established. They were randomly divided into 3 groups of traditional dressing, biological dressing and negative pressure wound therapy (NPWT) (n=6 each), according to the random number table. Eschar excision was performed three days later. The wound bed was observed and wound tissue was harvested for counting the quantity of bacteria, tissue dry wet ratio, measuring the level of tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β and IL-6, the amount of collagen fibers and the microvessel density instantly and again seven days later. Statistical analyses were performed.

RESULTS

The NPWT group was better than other groups by observing the wound bed. The quantity of bacteria of traditional dressing group, biological dressing group and NPWT group at the time point of seven days after escharectomy turned out to be (9.4±1.5)×10(4,) (8.1±2.7)×10(4,) (3.9±0.7)×10(4) cfu/g, the NPWT group was significantly lower than traditional dressing group and biological dressing group (both P<0.05), and all lower than that at the time point of the day when escharectomy was performed (576.9±169.5)×10(4,) (589.9±99.6)×10(4,) (583.0±160.4)×10(4) cfu/g ( all P<0.05). There were no statistically significant differences among three groups at two time points in tissue dry wet ratio (all P>0.05). The IL-6 of biological dressing group was higher than that of traditional dressing group at the time point of seven days after the eschar excision was performed[(94±10) vs (76±8) ng/L, P<0.05]. The amount of collagen fibers of three group at the time point of seven days after escharectomy turned out to be (60±9), (55±12), (77±17). The NPWT group was significantly higher than traditional dressing group and biological dressing group (P<0.05), and all higher than that at the time point of the day when escharectomy was performed[(39±6), (39±11), (38±6)](all P<0.05). The microvessel density of three groups at the time point of seven days after escharectomy turned out to be (42±6), (53±4), (82±10). The NPWT group was higher than that of the other two groups, and biological dressing group was higher than that of traditional dressing group (all P<0.05). The biological dressing group and NPWT group were both higher than that of the day when the eschar excision was performed (36±5) and (36±5) (P<0.05).

CONCLUSIONS

NPWT is the optimal selection for wound to inhibit the growth of bacteria, promote the accumulation of collagen and tissue vascularization. But these managements have similar effects on reducing tissue edema and inflammatory reaction.

[Evaluation of physical function for the end-stage osteoarthritis patient waiting for the total knee replacement]

OBJECTIVE

To collect comprehensive data of the physical function of the end-stage osteoarthritis (OA) patients, and compare it with patients with mild OA. To evaluate the correlations among pain, self-reported questionnaire, performance based physical function and actual daily life activity level.

METHODS

In this prospective study, the comprehensive physical function parameters of 87 end stage OA patients waiting for total knee replacement, and that of 60 patients with mild OA [Kellgren-Lawrence (K-L) grade 0-2] were collected. The comprehensive physical function parameters including: age, height, body weight, 30 s chair stand test (30-CST), 40 m fast-paced walk test (40-FPWT), 12 steps stair climb test (12-SCT), timed up & go test (TUG), 6 minutes walk test (6-MWT), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), knee society score (KSS), visual analogue scale (VAS) pain scale, and everyday steps counts for continuous 7 days. The data were analyzed with the soft ware SPSS 22.0. The descriptive report of all the parameters was made. Because the Kolmogorv-Smirnov test results for all the parameters were negative for normal distribution, nonparative Mann-Whitney test was used to analysis the differences between the two groups, as well as the Spearman test for the correlations.

RESULTS

All the parameters of the mild OA group were better than those of the end stage group, and the differences were significant (P<0.05). In the mild OA group, there were no correlations or weak correlations between all the physical function test and questionnaire, however, in the end stage group, the correlations were weak, moderate, or strong.

CONCLUSION

The usage of lots of different physical parameters from Chinese OA patients were reported in this study. The results showed that there are no good correlations among performance based physical function test, actual daily activity level, self reported questionnaires, and the pain scales. More comprehensive evaluation for the OA patients needs to be made, in order to make better decision for arthroplasty.

IL-6 enriched lung cancer stem-like cell population by inhibition of cell cycle regulators via DNMT1 upregulation

Tumors are influenced by a microenvironment rich in inflammatory cytokines, growth factors and chemokines, which may promote tumor growth. Interleukin-6 (IL-6) is a multifunctional cytokine and known as a regulator of immune and inflammation responses. IL-6 has also been reported to be associated with tumor progression and chemoresistance in different types of cancers. In our study, we demonstrated that IL-6 enriches the properties of lung cancer stem-like cells in A549 lung cancer cells cultured in spheroid medium. IL-6 also promotes sphere formation and stem-like properties of A549 cells by enhancing cell proliferation. Methylation-specific polymerase chain reaction (PCR) was performed and revealed that IL-6 increased methylation of p53 and p21 in A549 cancer cells. Western blot analysis and quantitative real-time PCR demonstrated that IL-6 increased the expression of DNA methyltransferase 1 (DNMT1) in A549 cells cultured in spheroid medium, but not the expression of DNMT3a or DNMT3b. Knockdown of DNMT1 eliminated IL-6-mediated hypermethylation of cell cycle regulators and enrichment of lung cancer stem-like properties. In conclusion, our study, for the first time, shows that the IL-6/JAK2/STAT3 pathway upregulates DNMT1 and enhances cancer initiation and lung cancer stem cell (CSC) proliferation by downregulation of p53 and p21 resulting from DNA hypermethylation. Upon blockage of the IL-6/JAK2/STAT3 pathway and inhibition of DNMT1, the proliferation of lung CSCs was reduced and their formation of spheres and ability to initiate tumor growth were decreased. These data suggest that targeting of the IL-6/JAK2/STAT3 signaling pathway and DNMT1 may become important strategies for treating lung cancer.

Rapid diagnosis of Naja atra snakebites

BACKGROUND

The clinical diagnosis of snakebites is critical and necessary in many parts of the world, especially in Southeastern Asia, where venomous snakebites are a burden on public health. It is difficult to define or recognize the species of venomous snake because of the overlapping clinical manifestations of envenomations. A quick and reliable method for identifying the snake species is necessary. We designed and tested a strip of lateral flow system for the diagnosis of cobra snake bites in Taiwan.

METHODS

We developed a kit based on an immunochromatographic method for rapid detection of cobra (Naja atra) venom in human serum. The test and control lines composed of 1 mg/ml polyclonal duck antivenom and 0.5 mg/ml goat anti-rabbit immunoglobulin antibody solutions, respectively, were coated on nitrocellulose strips. Colloidal gold was conjugated with rabbit polyclonal anti-cobra venom antibodies. From July 2007 to December 2012, we used the kit to test serum from snakebite patients and to examine the agreement between our rapid test and the currently used sandwich enzyme-linked immunosorbent assay (ELISA).

RESULTS

Our kit was able to detect cobra venom in serum samples in 20 minutes with a detection limit of 5 ng/ml. An absence of cross-reactivity with other non-cobra venoms from Taiwan was noted in vitro. A total of 88 snakebite patients (34 cobra and 54 other non-cobra) were tested. The sensitivity of the strips based on the ELISA results was 83.3% and the specificity was 100%. There was a strong agreement between the results of the ELISA and immunochromatographic strips (κ = 0.868).

DISCUSSION AND CONCLUSIONS

This data indicates that an immunochromatographic strip might be suitable for cobra venom detection and could be used as a quick diagnostic tool in cases of N. atra snakebite.

p53 and Sp1 cooperate to regulate the expression of Epstein-Barr viral Zta protein

Epstein-Barr virus (EBV) belongs to the gammaherpesvirus family. To produce infectious progeny, EBV reactivates from latency into the lytic cycle by expressing the determinative lytic transactivator, Zta. In the presence of histone deacetylase inhibitor (HDACi), p53 is a prerequisite for the initiation of the EBV lytic cycle by facilitating the expression of Zta. In this study, a serial mutational analysis of Zta promoter (Zp) indicated an important role for the ZID element in responding to HDACi induction and p53 binds to this ZID element together with Sp1, a universal transcription factor. Abolition of the DNA-binding ability of Sp1 reduces the inducibility of ZID by HDACi and also reduces the amount of p53 binding to ZID. Finally, it was shown that EBV in p53-positive-lymphoblastoid cell lines (LCLs) can enter into the lytic cycle spontaneously; however, knockdown of p53 in LCLs leads to retardation of EBV reactivation.

Identification of tristetraprolin as a factor that modulates the stability of the TAFI transcript through binding to the 3'-untranslated region

BACKGROUND

Thrombin-activatable fibrinolysis inhibitor (TAFI) is a basic carboxypeptidase zymogen encoded by the human gene CPB2. TAFI constitutes a molecular link between coagulation and fibrinolysis, and between coagulation and inflammation. The 3'-untranslated region (UTR) of the human CPB2 mRNA plays a key role in regulating CPB2 mRNA abundance, but the exact mechanisms that mediate this regulation are largely unexplored.

OBJECTIVES

To pinpoint cis-acting elements in the CPB2 3'-UTR that act as stability determinants and to identify protein factors binding to these sites.

METHODS

We constructed a series of plasmids encoding mRNAs containing rabbit β-globin sequences (as a reporter) fused to sequences of the CPB2 3'-UTR (encompassing 5' and internal deletions). These plasmids were transfected into HepG2 (human hepatoma) cells and the stability of the fusion transcripts measured. We performed a series of gel mobility shift analyses using RNA probes encompassing putative (in)stability elements.

RESULTS

We identified one element conferring stability and three elements conferring instability. Supershift assays identified the protein bound to the site between the second and third polyadenylation sites as tristetraprolin (TTP). Mutation of the TTP site abolished TTP binding in gel mobility shift assays and also stabilized β-globin/CPB2 fusion transcripts. TTP knockdown stabilized the fusion transcript containing the TTP site, but not a fusion transcript in which this site was mutated.

CONCLUSIONS

Our findings are indicative of a role for TTP in constitutive, and perhaps regulated, control of CPB2 mRNA stability and hence abundance.

Interleukin-10 promoter polymorphisms associated with susceptibility to lumbar disc degeneration in a Chinese cohort

We investigated a possible association between interleukin (IL)-10 single nucleotide polymorphisms (SNPs) and susceptibility to and severity of lumbar disc degeneration (LDD) in a Chinese cohort of 320 patients with LDD and 269 gender- and age-matched controls. The degree of disc degeneration was determined by magnetic resonance imaging using Schneiderman's classification. Genetic analysis of IL-10 promoter polymorphisms (at -1082 A/G, -819 T/C, and -592 A/C) was carried out by PCR-RFLP. A total of 134 herniated lumbar intervertebral discs were collected during surgery for IL-10 mRNA detection. For SNPs at -592, the A allele and AA genotype frequencies were significantly higher in LDD patients than in controls. Similarly, the AA genotype and A allele frequencies at -1082 were significantly higher in cases than in controls. Among the LDD subjects, carriers of AA at -592 and GG at -1082 had significantly lower mean IL-10 mRNA expression than the other two genotypes. The SNPs at each locus were not significantly associated with severity grade in the LDD patients. Logistic regression analyses showed that the AA at -1082, AA at -592, and IL-10 mRNA expression level were independent risk factors for LDD. We conclude that the IL-10 SNPs at -1082 A/G and -592 A/C as well as IL-10 mRNA in the herniated lumbar intervertebral discs are associated with susceptibility to LDD in this Chinese cohort, but not with disease severity.

Mesenchymal stem cells enhance lung cancer initiation through activation of IL-6/JAK2/STAT3 pathway

BACKGROUND

The role of mesenchymal stem cells (MSCs) and IL-6 in lung cancer has not been well-addressed. We aimed to determine if MSCs can enhance the ability of tumor initiation of lung cancer cells, and link MSCs with activation of the IL-6/JAK2/STAT3 signaling pathway.

MATERIALS AND METHODS

Lung cancer cell lines A549 and CL1-5 were directly or indirectly cocultured with MSCs. Spheres were defined as cell colonies with >50% area showing 3-dimensional structure and blurred cell margins. Cells without and with MSCs were injected into NOD/SCID mice. The percentage of tumor formation was determined. The influence of the IL-6/JAK2/STAT3 signaling pathway in cancer cell sphere formation and tumor growth were investigated.

RESULTS

A very small number of lung cancer cells, when mixed with otherwise non-tumorigenic MSCs, obtained de novo tumorigenicity when injected subcutaneously and allowed to form a tumor xenograft. Secretion of IL-6 from MSCs increased activation of the JAK2/STAT3 pathway in cancer cells, and enhanced sphere formation and tumor initiation. A reduced capacity of tumor formation of A549 and CL1-5 lung cancer cells when IL-6 was inhibited in MSCs or STAT3 was silenced in A549 and CL1-5 admixed with MSCs.

CONCLUSIONS

Culture of A549 or CL1-5 lung cancer cells with MSCs increased sphere formation, drug resistance, and overexpression of pluripotency markers through activation of the IL-6/JAK2/STAT3 pathway. MSCs enhanced the capability of A549 and CL1-5 lung cancer cells to form tumors in immunodeficient mice. Blockade of the IL-6/JAK2/STAT3 pathway attenuated the capability of A549 and CL1-5 cells to form tumors.

Bias-dependent conductive characteristics of individual GeSi quantum dots studied by conductive atomic force microscopy

The bias-dependent electrical characteristics of individual self-assembled GeSi quantum dots (QDs) are investigated by conductive atomic force microscopy. The results reveal that the conductive characteristics of QDs are strongly influenced by the applied bias. At low (-0.5 to - 2.0 V) and high (-2.5 to - 4.0 V) biases, the current distributions of individual GeSi QDs exhibit ring-like and disc-like characteristics respectively. The current of the QD's central part increases more quickly than that of the other parts as the bias magnitude increases. Histograms of the magnitude of the current on a number of QDs exhibit the same single-peak feature at low biases, and double- or three-peak features at high biases, where additional peaks appear at large-current locations. On the other hand, histograms of the magnitude of the current on the wetting layers exhibit the same single-peak feature for all biases. This indicates the conductive mechanism is significantly different for QDs and wetting layers. While the small-current peak of QDs can be attributed to the Fowler-Nordheim tunneling model at low biases and the Schottky emission model at high biases respectively, the large-current peak(s) may be attributed to the discrete energy levels of QDs. The results suggest the conductive mechanisms of GeSi QDs can be regulated by the applied bias.