[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.

[Clinical significance of CTP combined with ABIC score in predicting the short-term prognosis of patients with hepatitis B virus-related acute-on-chronic liver failure]

Objective: To investigate the risk factors affecting the short-term prognosis of patients with hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF), and establish a new scoring model to predict the short-term prognosis of patients. Methods: This study enrolled 222 patients with HBV-ACLF. According to their clinical outcomes during hospitalization and 90 days after discharge, they were divided into survival and death group. Clinical data were collected to calculate the Child-Turcotte-Pugh (CTP), model for end-stage liver disease (MELD), albumin-bilirubin (ALBI), and age-bilirubin-international normalized ratio-creatinine (ABIC) scores for prognosis. Multivariate logistic regression analysis was used to analyze the independent risk factors affecting 90-day mortality in HBV-ACLF patients. Cox regression model was used to establish a new prediction model. Area under the receiver operating characteristic curve was used to calculate short-term prognostic value of the models. K-M survival curve was used to predict the prognosis of patients. Results: CTP and ABIC scores were independent risk factors for 90-day mortality in HBV-ACLF patients, and the risk of death from liver failure had increased with increase of score. Cox regression model established a new predictive model CTP-ABIC = 0.551 × CTP + 0.297 × ABIC. Area under the receiver operating characteristic curve of all three scoring models (CTP, ABIC and CTP-ABIC) were 0.878, 0.829, 0.927, respectively. CTP-ABIC score was superior to the CTP and ABIC score (P value < 0.001). Patients with CTP-ABIC score ≥9.08 had higher mortality rate than patients with CTP-ABIC score < 9.08, and the difference was statistically significant (P < 0.001). Conclusion: All three scoring systems can predict short-term prognosis in patients with HBV-ACLF, but the accuracy of CTP-ABIC is superior.

Sugar accumulation and growth of lettuce exposed to different lighting modes of red and blue LED light

The present study evaluated the growth response and sugar accumulation of lettuce exposed to different lighting modes of red and blue LED light based on the same daily light integral (7.49 μmol·m-2). Six lighting treatments were performed, that were monochromatic red light (R), monochromatic blue light (B), simultaneous red and blue light as the control (RB, R:B = 1:1), mixed modes of R, B and RB (R/RB/B, 4 h R to 4 h RB and then 4 h B), and alternating red and blue light with alternating intervals of 4 h and 1 h respectively recorded as R/B(4 h) and R/B(1 h). The Results showed that different irradiation modes led to obvious morphological changes in lettuce. Among all the treatments, the highest fresh and dry weight of lettuce shoot were both detected with R/B(1 h), significantly higher than the other treatments. Compared with plants treated with RB, the contents of fructose, glucose, crude fiber as well as the total sweetness index (TSI) of lettuce were significantly enhanced by R treatment; meanwhile, monochromatic R significantly promoted the activities of sucrose degrading enzymes such as acid invertase (AI) and neutral invertase (NI), while obviously reduced the activity of sucrose synthesizing enzyme (SPS). Additionally. The highest contents of sucrose and starch accompanied with the strongest activity of SPS were detected in plants treated with R/B(1 h). The alternating treatments R/B(4 h) and R/B(1 h) inhibited the activity of SS, while enhanced that of SPS compared with the other treatments, indicating that different light environment might influence sugar compositions via regulating the activities of sucrose metabolism enzymes. On the whole, R/B(1 h) was the optimal lighting strategy in terms of lettuce yield, taste and energy use efficiency in the present study.

The changing gender landscape of pediatric urology fellowship: results from a survey of fellows and recent graduates

INTRODUCTION

Women are entering the subspecialty of pediatric urology at an accelerated rate. Gender differences affecting fellowship and job selection have been identified in other fields of medicine.

OBJECTIVE

The objective of this study was to understand gender differences in pediatric urology fellowship and job selection and how they may affect the workforce.

STUDY DESIGN

A 47-question electronic survey consisting of questions regarding demographics, residency training, and factors influencing fellowship and job selection was distributed to current fellows and recent graduates in pediatric urology in May 2017.

RESULTS

A total of 111 recent and current fellows were contacted, and 72% completed the survey (55% female [F] and 45% male [M]; 61% current fellows and 39% recent fellows). Respondents rated factors important in choosing pediatric urology on a scale of 1-5 (1, not important and 5, extremely important), and the top three for both genders were 1-working with children, 2-influential mentors, and 3-bread and butter cases such as inguinal orchiopexy. During residency, 93% of respondents reported having influential mentors in pediatric urology. However, mentorship was more important in fellowship choice for males than females (3.6 F, 4.1 M; P-value = 0.048), and 45% reported having only male mentors. Rating factors important in job choice on a scale of 1-5, respondents reported the top factors as 1-rapport with partners/mentorship (4.5), 2-geography/family preferences (4.3), and 3-participation in mentoring/teaching (3.8). Although most job selection criteria were rated similarly between genders, females rated call schedule higher than males (3.5 F, 2.9 M, P-value = 0.009). Although most females and males (79% of F, 78% of M, P-value = 0.868) sought primarily academic positions, a smaller proportion of females accepted academic positions (52% of F, 72% of M, P-value 0.26), and females reported lower satisfaction regarding the availability of jobs on a scale of 1-5 (1, very dissatisfied and 5, very satisfied; 3.1 F, 3.7 M; P-value = 0.034), particularly in academic positions (3.1 F, 3.7 M; P-value = 0.06). This difference was more pronounced in current fellows than recent graduates and may represent a worsening trend.

CONCLUSION

Although significant gender differences in fellowship and job selection may exist in other fields, we found that women and men choose pediatric urology fellowships and jobs using similar criteria, which include work-life balance. Gender differences exist in the influence of mentors, indicating a need for more female mentors. While men and women sought similar types of jobs, women were less satisfied with the availability of jobs, particularly academic jobs, than men, which warrants further investigation.

[Value of serum matrix metalloproteinase 3 in the assessment of early rheumatoid arthritis]

OBJECTIVE

To investigate the expression level of serum matrix metalloproteinase 3 (MMP3) in early rheumatoid arthritis (ERA) patients with normal C-reaction protein (CRP) or erythrocyte sedimentation rate (ESR), and the significance in disease assessment.

METHODS

In the study, 133 cases of early RA patients, 25 osteoarthritis (OA) patients and 60 healthy controls in Peking University People's Hospital from 2011 to 2015 were included. The RA patients were further divided into 4 groups according to levels of CRP and ESR: 88 patients with increased CRP and increased ESR, 15 patients with normal CRP and normal ESR, 17 patients with normal CRP but increased ESR, and 13 patients with increased CRP but normal ESR. All the clinical information of the patients was collected, and the serum MMP3 levels of both patients and healthy controls were detected by enzyme-linked immune sorbent assay (ELISA).

RESULTS

The serum MMP3 level of RA patients with normal CRP and/or normal ESR [(72.89±6.34) μg/L] was obviously higher than that of OA patients [(42.87±4.14) μg/L] (P=0.002) and healthy controls [(31.62±2.88) μg/L] (P<0.001). The serum MMP3 levels of the patients with normal CRP and normal ESR [(47.04±9.64) μg/L] were higher than those of the healthy controls, and there was statistical significance between the two groups (P<0.05). The serum MMP3 levels of the patients with increased CRP but normal ESR [(94.18±9.11) μg/L] and the patients with normal CRP but increased ESR [(79.42±10.60) μg/L] were both higher than those of the OA patients and healthy controls, and there was obvious statistical difference (P<0.05). In the early RA patients with normal CRP and/or normal ESR, the serum MMP3 level was positively correlated with the CRP level (r=0.336, P=0.024). The positive rate of MMP3 in the patients with normal CRP and/or normal ESR was 44.44%, higher than the positive rate of CRP (28.89%) and the positive rate of ESR (37.78%). In these early RA patients, the positive rate was 52.94% in the patients with normal CRP but increased ESR and 53.85% in the patients with increased CRP but normal ESR.

CONCLUSION

The detection of the serum MMP3 level was significant in the assessment of early RA patients within 2-year duration who had normal CRP or ESR value.

Very high external quantum efficiency and wall-plug efficiency 527 nm InGaN green LEDs by MOCVD

We demonstrate very high luminous efficacy InGaN-based green light-emitting diodes (LEDs) grown on c-plane patterned sapphire substrates (PSS) using metal organic chemical vapor deposition (MOCVD). The 527 nm green LEDs show a peak external quantum efficiency (EQE) of 53.3%, a peak wall-plug efficiency (WPE) of 54.1% and a peak luminous efficacy of 329 lm/W, respectively. A high EQE of 38.4%, a WPE of 32.1% and a very low forward voltage of 2.86 V were obtained at a typical working current density of 20 A/cm². By operating low cost green LEDs at a low current density, our devices (0.5 mm²) demonstrating an EQE and a WPE higher than 50% and an efficacy of 259 lm/W at 4 A/cm² with an output power of 24 mW. High crystal quality of the InGaN/GaN MQWs was characterized by X-ray diffraction (XRD) and the advantage of the epitaxy design was investigated by APSYS software simulation. These results provide a simple way to achieve very high efficiency InGaN green LEDs.

Oncogenic activity of poly (ADP-ribose) glycohydrolase

Poly (ADP-ribosylation), known as PARylation, is a post-translational modification catalyzed by poly (ADP-ribose) polymerases (PARP) and primarily removed by the enzyme poly (ADP-ribose) glycohydrolase (PARG). While the aberrant removal of post-translation modifications including phosphorylation and methylation has known tumorigenic effects, deregulation of PARylation has not been widely studied. Increased hydrolysis of PARylation chains facilitates cancer growth through enhancing estrogen receptor (ER)-driven proliferation, but oncogenic transformation has not been linked to increased PARG expression. In this study, we find that elevated PARG levels are associated with a poor prognosis in breast cancers, especially in HER2-positive and triple-negative subtypes. Using both in vitro and in vivo models, we demonstrate that heightened expression of catalytically active PARG facilitates cell transformation and invasion of normal mammary epithelial cells. Catalytically inactive PARG mutants did not recapitulate these phenotypes. Consistent with clinical data showing elevated PARG predicts poor outcomes in HER2+ patients, we observed that PARG acts in synergy with HER2 to promote neoplastic growth of immortalized mammary cells. In contrast, PARG depletion significantly impairs the growth and metastasis of triple-negative breast tumors. Mechanistically, we find that PARG interacts with SMAD2/3 and significantly decreases their PARylation in non-transformed cells, leading to enhanced expression of SMAD target genes. Further linking SMAD-mediated transcription to the oncogenicity of PARG, we show that PARG-mediated anchorage-independent growth and invasion are dependent, at least in part, on SMAD expression. Overall, our study underscores the oncogenic impact of aberrant protein PARylation and highlights the therapeutic potential of PARG inhibition in breast cancer.

[Bioinformatics Analysis of Hepatocellular Carcinoma Related Gene and Construction of a Protein-Protein Interaction Network]

OBJECTIVE

To identify key genes associated with hepatocellular carcinoma (HCC) through analyzing the functions of differentially expressed genes (DEGs) and the interactions of their encoded proteins.

METHODS

The microarray dataset GSE45436 was downloaded from the Gene Expression Omnibus (GEO) database. The DEGs in hepatocellular carcinoma and adjacent tissues were analyzed using the R software. Bioinformatics tools DAVIA, STRING, GEPIA, Cytoscape, cBioPortal were applied to analyze the biological functions of the DEGs and their encoded protein interactions.

RESULTS

A total of 375 DEGs were identified, consisting of 296 downregulated genes and 99 upregulated genes. The enriched functions and pathways of the DEGs included cell cycle, p53 signaling pathway, complement activation, and metabolism of xenobiotics by cytochrome P450. The PPIanalysis showed that TOP2A might be involved in the carcinogenesis of HCC.

CONCLUSIONS

Differentially expressed genes in hepatocellular carcinoma and adjacent tissues and their encoded protein interactions revealed by the bioinformatics analysis provide guidance for further research on the molecular mechanism and targeted therapy of HCC. TOP2A may play a key role in HCC.

Serum hepatitis B surface antigen correlates with fibrosis and necroinflammation: A multicentre perspective in China

The kinetics of serum hepatitis B surface antigen (HBsAg) during the natural history of hepatitis B virus (HBV) infection has been studied, but the factors affecting them remain unclear. We aimed to investigate the factors affecting HBsAg titres, using data from multicentre, large-sized clinical trials in China. The baseline data of 1795 patients in 3 multicentre trials were studied, and the patients were classified into 3 groups: hepatitis B early antigen (HBeAg)-positive chronic HBV infection (n = 588), HBeAg-positive chronic hepatitis B (n = 596), and HBeAg-negative chronic hepatitis B (n = 611). HBsAg titres in the different phases were compared, and multiple linear progression analyses were performed to investigate the implicated factors. HBsAg titres varied significantly in different phases (P = .000), with the highest (4.60 log10 IU/mL [10%-90% confidence interval: 3.52 log10 IU/mL-4.99 log10 IU/mL]) in patients with HBeAg-positive chronic HBV infection. In all phases, age and HBV DNA were correlated with serum HBsAg level. In HBeAg-positive chronic hepatitis B patients, a negative correlation between HBsAg titres and fibrosis stage was observed. Alanine amonitransferase or necroinflammatory activity was also correlated with HBsAg titres in HBeAg-negative chronic hepatitis B patients. In conclusion, decreased HBsAg titres may be associated with advancing fibrosis in HBeAg-positive chronic hepatitis B patients or increased necroinflammation in those with HBeAg-negative chronic hepatitis B. Our findings may help clinicians better understand the kinetics of HBsAg and provide useful insights into the management of this disease.

Lactic acid bacteria-fermented product of green tea and Houttuynia cordata leaves exerts anti-adipogenic and anti-obesity effects

Obesity is associated with higher risks of developing diabetes and cardiovascular disease. Green tea, rich in polyphenolic compounds such as epigallocatechin gallate (EGCG) and epigallocatechin (EGC), has been shown to display anti-obesity effects. Houttuynia cordata leaves have also been shown to exhibit anti-obesity effects due to their chlorogenic acid content. Lactic acid bacteria are able to increase the production of polyphenolic compounds. This study aims to develop a novel anti-obesity fermentation product by combining H. cordata leaf tea with green tea, using Lactobacillus paracasei subsp. paracasei NTU 101 (NTU 101) for fermentation due to the advantages of bioconverting the poly-phenolic compounds. The regulation of adipogenesis factors and the anti-obesity effect of the NTU 101-fermented tea were evaluated in an in vitro 3T3-L1 pre-adipocyte model and an in vivo obese rat model, respectively. The results show that the NTU 101-fermented tea, which contained higher EGCG, EGC, and chlorogenic acid levels than unfermented tea, was able to inhibit the lipogenesis of mature 3T3-L1 adipocytes by the stimulation of lipolysis. Furthermore, the body weight gain, body fat pad, and feeding efficiency of obese rats, induced with a high fat diet, were decreased by the oral administration of NTU 101-fermented tea. The significant anti-obesity effect was probably due to lipolysis. However, NTU 101 bacteria cells and EGCG may also act as functional ingredients to contribute to the anti-obesity effects of NTU 101-fermented products.

[Precision of three-dimensional printed brackets]

OBJECTIVE

This study was based on digital orthodontic diagnosis work flow for indirect bonding transfer tray model design and three-dimensional (3D) printing, and the aim of this paper was to inspect the dimensional accuracyof 3D printed brackets, which is the foundation of the follow up work and hoped that will illuminate the clinical application of the digital orthodontics work flow.

METHODS

The samples which consisted of 14 cases of patients with malocclusion from Department of Orthodontics Peking University were selected, including 8 cases with tooth extraction and 6 cases without tooth extraction. All the 14 patients were taken intra-oral scan (Trios 3Shape, Denmark) and cone-beam computed tomography (CBCT, NewTom 3G volumetric scanner, Aperio Service,Italy)shooting after periodontal treatment. STL data and DICOM data were obtained from intraoral scans and CBCT images.Data segmentation, registration, fusion, automatic tooth arrangement, virtual positioning of orthodontic appliance and conversion the coordinates of malocclusion model were all done with self-programming software. The data of 3D printing model with brackets on it were output finally and printed out with EDEN260V (Objet Geometries, Israel) to make indirect bonding transfer tray. Digital vernier caliper was used to measure the length and width of upper and lower left brackets and buccal tubes on those 3D models after removal of surrounding supporting material by ultrasonic vibration and water-spray. Intra-examiner reliability was assessed by using intra-class correlation coefficients (ICC), and one-sample T test was used to compare the measurements with the standard dimensional data of the brackets.

RESULTS

There were significant differences which range in 0.04-0.17 mm between the 13 items out of the 19 measurement items. Except for the length of the lower left premolars'brackets, mean values of the other items were greater than the test value.

CONCLUSION

Although the measurement results in the width of brackets and the width and length of the buccal tubes obtained experimentally were slightly larger than the test value,this may not reduce the accuracy of indirect bonding procedure in clinic necessarily. Whether the differences which range in 0.04-0.17 mm would actually affect the retention and positioning of brackets needs to be confirmed by further studies.

Optically pumped lasing with a Q-factor exceeding 6000 from wet-etched GaN micro-pyramids

We report the observation of room-temperature optically pumped lasing modes from a single GaN pyramid microcavity on a metallic mirror. The mode at 367.2 nm exhibits a low threshold (0.4-0.5  MW/cm²) and a narrow linewidth (0.054 nm), by which the quality factor can be estimated to be >6000. These lasing behaviors can be attributed to the specific wet-etching approach by selectively etching away defects and pyramid geometry with bottom Ag reflectors for better light confinement. Optical resonances in these pyramids are further investigated in combination with three-dimensional finite-difference time-domain simulations.

Hierarchical Image Segmentation Based on Iterative Contraction and Merging

In this paper, we propose a new framework for hierarchical image segmentation based on iterative contraction and merging. In the proposed framework, we treat the hierarchical image segmentation problem as a sequel of optimization problems, with each optimization process being realized by a contraction-and-merging process to identify and merge the most similar data pairs at the current resolution. At the beginning, we perform pixel-based contraction and merging to quickly combine image pixels into initial region-elements with visually indistinguishable intra-region color difference. After that, we iteratively perform region-based contraction and merging to group adjacent regions into larger ones to progressively form a segmentation dendrogram for hierarchical segmentation. Comparing with the state-of-the-art techniques, the proposed algorithm can not only produce high-quality segmentation results in a more efficient way, but also keep a lot of boundary details in the segmentation results.

A novel function of TBK1 as a target of Cdon in oligodendrocyte differentiation and myelination

During central nervous system development, oligodendrocyte progenitors elaborate multiple branched processes to contact axons and initiate myelination. Using cultured primary rat oligodendrocytes (OLGs), we have recently demonstrated that a cell surface protein belonging to the immunoglobulin superfamily, cell adhesion molecule-related, down-regulated by oncogenes (Cdon), is important in initiating OLG differentiation and axon myelination by promoting the formation of branched cellular processes; however, the molecular mechanism by which Cdon regulates OLG differentiation is not known. Here, using Cdon immunoprecipitation (IP) and liquid chromatography-tandem mass spectrometry analysis, we identified serine/threonine kinase TANK-binding kinase 1 (TBK1) as a candidate novel target of Cdon. We confirmed this interaction using co-IP and immunofluorescence with TBK1 antibodies, showing that TBK1 partly co-localizes with Cdon along cellular processes in puncta-like structures. We show that TBK1 is expressed throughout OLG differentiation, and surprisingly, that levels of phosphorylated TBK1 (ser172) increase during OLG maturation, while total levels of TBK1 protein decrease. To investigate function, TBK1 expression was knocked down using siRNA in OLG primary cultures, reducing protein levels by 69%. Two myelin-specific proteins, myelin basic protein and myelin-associated glycoprotein, were similarly reduced when examined at day 2 and day 4 of OLG differentiation. Reduced Cdon or TBK1 expression also decreased Akt phosphorylation at Threonine 308 in OLG. Our findings provide evidence that a Cdon-TBK1 complex is associated with Akt phosphorylation and early OLG differentiation.

Role of Sonic Hedgehog Signaling in Oligodendrocyte Differentiation

During development, the secreted molecule Sonic Hedgehog (Shh) is required for lineage specification and proliferation of oligodendrocyte progenitors (OLPs), which are the glia cells responsible for the myelination of axons in the central nervous system (CNS). Shh signaling has been implicated in controlling both the generation of oligodendrocytes (OLGs) during embryonic development and their production in adulthood. Although, some evidence points to a role of Shh signaling in OLG development, its involvement in OLG differentiation remains to be fully determined. The objective of this study was to assess whether Shh signaling is involved in OLG differentiation after neural stem cell commitment to the OLG lineage. To address these questions, we manipulated Shh signaling using cyclopamine, a potent inhibitor of Shh signaling activator Smoothened (Smo), alone or combined with the agonist SAG in OLG primary cultures and assessed expression of myelin-specific markers. We found that inactivation of Shh signaling caused a dose-dependent decrease in myelin basic protein (MBP) and myelin associated glycoprotein (MAG) in differentiating OLGs. Co-treatment of the cells with SAG reversed the inhibitory effect of cyclopamine on both myelin-specific protein levels and morphological changes associated with it. Further experiments are required to elucidate the molecular mechanism by which Shh signaling regulates OLG differentiation.

Neuropsychiatric manifestations in pediatric systemic lupus erythematosus: a 20-year study

The objective of this study was to investigate the manifestations, treatment and outcome of neuropsychiatric (NP) involvement in pediatric systemic lupus erythematosus (SLE) patients. The charts of 185 pediatric patients with SLE diagnosed between 1985 and 2005 in a tertiary referral hospital were retrospectively reviewed. NPSLE were defined using the American College of Rheumatology NPSLE case definitions. NPSLE developed in 34.6% (64/185) of the patients. The mean onset age was 15.2 years. Fourteen patients (21.9%) had NP manifestations on initial diagnosis of SLE. The median duration from the onset of SLE to NP manifestation was 11 months. The most frequent NP manifestations were seizure disorder (84.4%), ischemic stroke (28.1%) and psychosis (21.9%). However, the prevalence of manifestations of NPSLE might be underestimated by the retrospective design of our study. Higher mean C3/C4 levels, less percentage of anti-dsDNA antibodies elevation and higher percentage of elevated anticardiolipin antibodies were observed in NPSLE events than in non-NPSLE events ( P 0.05). The mortality rate of NPSLE patients decreased from 52.2% in 1985–1994 cohort to 27.8% in 1995–2005 cohort. In the past 10 years, the leading cause of death in NPSLE patients was NPSLE itself. NPSLE is common in pediatric SLE patients. It has diverse manifestations and a high mortality.

[Inhibitory effect of imrecoxib combined with lobaplatin on tumor growth and lymph node metastasis of human lung cancer xenografts in nude mice]

OBJECTIVE

To evaluate the inhibitory effect of imrecoxib combined with lobaplatin on tumor growth and lymph node metastasis of human lung adenocarcinoma xenografts in nude mice, and to explore its possible mechanisms.

METHODS

Human lung cancer A549 cells were injected into Bal B/c nude mice subcutaneously. Twenty-eight healthy male nude mice were randomly divided into 4 groups: the control group, imrecoxib group, lobaplatin group and imrecoxib combined with lobaplatin group. Each group was treated with appropriate drugs and the tumor size was measured every five days. The expression of ezrin and E-cadherin protein was detected by immunohistochemistry and flow cytometry. Ezrin and E-cadherin mRNA were detected by real-time PCR.

RESULTS

The tumor inhibition rates of imrecoxib group, lobaplatin group and combination group were 36.7%, 54.6% and 69.2%, respectively. The tumor volumes of imrecoxib group [(905.33±113.31) mm(3)] and combination group [(507.74±77.50) mm(3)] were significantly lower than that of the control group (1355.33±189.04) mm(3) (P<0.05), and the tumor weights were significantly reduced [(1.13±0.14) g, (0.63±0.10) g respectively] vs. (1.69±0.24) g (P<0.05). The expressions of ezrin protein and mRNA in the imrecoxib group and combined treatment group were significantly lower than that of the control group (136.53±35.52, 74.72±19.48 vs. 175.62±21.16 for protein expression level; 0.54±0.03, 0.36±0.03 vs. 1.02±0.02 for mRNA expression level, respectively, P<0.05 for both), while the expression of E-cadherin protein and mRNA in the imrecoxib group and combined treatment group was significantly higher than that of the control group (253.78±38.87, 308.94±24.67 vs. 213.66±30.31 for protein expression level; 2.19±0.02, 3.02±0.02 vs. 1.05±0.03 for mRNA expression level, respectively, P<0.05 for both). There was a significant negative correlation between ezrin protein and E-cadherin protein (r=-0.737, P<0.01), as well as between ezrin mRNA and E-cadherin mRNA (r=-0.977, P<0.01).

CONCLUSIONS

Administration of imrecoxib combined with lobaphatin has inhibitory effects on the growth of non-small cell lung cancer xenografts and lymph node metastasis via down-regulated ezrin and upregulated E-cadherin. Imrecoxib and lobaplatin have a synergistic antitumor effect.

Cdon, a cell surface protein, mediates oligodendrocyte differentiation and myelination

During central nervous system development, oligodendrocyte progenitors (OLPs) establish multiple branched processes and axonal contacts to initiate myelination. A complete understanding of the molecular signals implicated in cell surface interaction to initiate myelination/remyelination is currently lacking. The objective of our study was to assess whether Cdon, a cell surface protein that was shown to participate in muscle and neuron cell development, is involved in oligodendrocyte (OLG) differentiation and myelination. Here, we demonstrate that endogenous Cdon protein is expressed in OLPs, increasing in the early differentiation stages and decreasing in mature OLGs. Immunocytochemistry of endogenous Cdon showed localization on both OLG cell membranes and cellular processes exhibiting puncta- or varicosity-like structures. Cdon knockdown with siRNA decreased protein levels by 62% as well as two myelin-specific proteins, MBP and MAG. Conversely, overexpression of full-length rat Cdon increased myelin proteins in OLGs. The complexity of OLGs branching and contact point numbers with axons were also increased in Cdon overexpressing cells growing alone or in coculture with dorsal root ganglion neurons (DRGNs). Furthermore, myelination of DRGNs was decreased when OLPs were transfected with Cdon siRNA. Altogether, our results suggest that Cdon participates in OLG differentiation and myelination, most likely in the initial stages of development.

Cloning and expression analysis of cysteine protease gene (MwCP) in Agropyron mongolicum Keng

In this study, a cysteine protease gene (MwCP) from Agropyron mongolicum Keng was isolated using RACE. Sequence analysis indicated that MwCP was 1473 bp, and it contained a 1134-bp open reading frame, which encoded 377 amino acids with a 24-amino acid N-terminal signal peptide. The results indicated that the MwCP protein was a new member of the papain C1A family, and it was predicted to be an extracellular, secretory stable hydrophilic protein. The secondary structure of MwCP was mainly composed of α-helices and random coils, and the space structure primarily contained α-helices, β-sheets, and β-turns. Homology analyses showed the 98% homology between MwCP amino acids and a cysteine protease found in Triticum aestivum (GenBank accession No. AAW21813.1). Analysis of mRNA using semi-quantitative RT-PCR indicated that during a 48-h drought stress period, MwCP was expressed during the 4th hour, and the expression level peaked during the 6th hour before declining to the original level. The results revealed that MwCP was involved in drought-resistant physiological processes of A. mongolicum. Moreover, the MwCP expression levels were highest in leaves, intermediate in roots, and lowest in stems.

Efficacious and safe orotracheal intubation for laboratory mice using slim torqueable guidewire-based technique: comparisons between a modified and a conventional method

BACKGROUND

Tracheal intubation of laboratory mice remains essential yet challenging for most researchers. The aim of this study was to investigate whether this procedure can be more efficiently and safely accomplished by a novel method using slim and torqueable guidewires to guide access to the trachea.

METHODS

This study was carried out in an animal laboratory affiliated to a tertiary medical center. Mice weighing 22 to 28 g were subjected to various open-chest experiments after being anesthetized with intraperitoneal ketamine (100 mg/kg) and lidocaine hydrochloride (10 mg/kg). The oropharyngeal cavity was opened with angled tissue forceps, and the trachea was transilluminated using an external light. The vocal cords were then crossed using either the Conventional method with a 38-mm-long, end-blunted stiff needle as a guide for insertion of a 22-gauge, 25-mm-long intravenous catheter into the trachea, or the Modified method utilizing using a 0.014-inch-thin torqueable wire as the guide to introduce an identical tube over it into the trachea. The epithelial integrity of the trachea was later examined histologically when the animals were sacrificed either immediately after the surgery or at 28 days post-surgery, depending on the corresponding research protocols.

RESULTS

Orotracheal intubation was successfully completed in all mice using either the Conventional (N = 42) or the Modified method (N = 50). With the Modified method, intubation took less time (1.73 vs. 2.17 min, Modified vs. Conventional, p < 0.001) and fewer attempts (1.0 vs. 1.33, p < 0.001), and there were fewer procedural difficulties (0% vs. 16.7%, p = 0.009) and complications (0% vs. 11.9%, p = 0.041) compared with the Conventional method. Histological analysis revealed a significantly lower incidence of immediate (0% vs. 39%, p < 0.001) and late (0% vs. 58%, p < 0.001) injuries to the tracheal epithelial lining with the Modified method compared to the Conventional method.

CONCLUSIONS

Tracheal intubation for laboratory mice can be completed efficiently, safely and atraumatically using the proposed Modified method employing readily available inexpensive instruments.