Advances in bacterial adsorption and transport of aromatic compounds / 生物工程学报

Aromatic compounds are a class of organic compounds with benzene ring(s). Aromatic compounds are hardly decomposed due to its stable structure and can be accumulated in the food cycle, posing a great threat to the ecological environment and human health. Bacteria have a strong catabolic ability to degrade various refractory organic contaminants (e.g., polycyclic aromatic hydrocarbons, PAHs). The adsorption and transportation are prerequisites for the catabolism of aromatic compounds by bacteria. While remarkable progress has been made in understanding the metabolism of aromatic compounds in bacterial degraders, the systems responsible for the uptake and transport of aromatic compounds are poorly understood. Here we summarize the effect of cell-surface hydrophobicity, biofilm formation, and bacterial chemotaxis on the bacterial adsorption of aromatic compounds. Besides, the effects of outer membrane transport systems (such as FadL family, TonB-dependent receptors, and OmpW family), and inner membrane transport systems (such as major facilitator superfamily (MFS) transporter and ATP-binding cassette (ABC) transporter) involved in the membrane transport of these compounds are summarized. Moreover, the mechanism of transmembrane transport is also discussed. This review may serve as a reference for the prevention and remediation of aromatic pollutants.

Effect of expressing of anti-PD-1 antibody in mouse mammary gland on spleen T cells in transgenic mice / 生物工程学报

This study aims to investigate the effect of anti-PD-1 antibody expressed in mouse mammary gland on the surface antigen protein of spleen T cells, cytokine expression, spleen CD4+ T cell proliferation and proliferation related pathways of transgenic mice at the cellular level. Transgenic mice expressing anti-human PD-1 antibody at 8 weeks of age without pregnancy and 18 weeks of age with lactation were divided into two groups, with transgenic negative mice in each group as the control. Spleen lymphocytes were extracted and the changes of spleen lymphocytes were detected. Compared with transgenic negative mice, the proportion of effector T cells of spleen T cells in the immune system of transgenic mice with anti-PD-1 antibody expressed in breast increased, the proportion of Treg cells decreased, and the IFN-γ, IL-17 and IL-2 expressed in CD4+ T cells increased in varying degrees. Moreover, IL-4, IL-10 and TGF-β in CD4+ T cells did not change, nor did some cell surface protein molecules related to T cell stimulate. There was no significant difference in T cell proliferation between transgenic positive and transgenic negative mice. In transgenic positive mice, the expression of phosphorylated proteins in PI3K/Akt/mTOR and RAS/MEK/ERK pathways were partially up-regulated, but the whole pathway was not completely up-regulated. Therefore, it is feasible to use transgenic mice as host to express monoclonal antibodies related to immune system such as anti-PD-1 antibody.

Enzyme-linked immunosorbent assays for quantification of MMMAE-conjugated ADCs and total antibodies in cynomolgus monkey sera / 药物分析学报

Antibody-drug conjugates(ADCs)are commonly heterogeneous and require extensive assessment of exposure-efficacy and exposure-safety relationships in preclinical and clinical studies.In this study,we report the generation of a monoclonal antibody against monomethyl auristatin E(MMAE)and the development,validation,and application of sensitive and high-throughput enzyme-linked immunosor-bent assays(ELISA)to measure the concentrations of MMAE-conjugated ADCs and total antibodies(tAb,antibodies in ADC plus unconjugated antibodies)in cynomolgus monkey sera.These assays were suc-cessfully applied to in vitro plasma stability and pharmacokinetic(PK)studies of SMADC001,an MMAE-conjugated ADC against trophoblast cell surface antigen 2(TROP-2).The plasma stability of SMADC001 was better than that of similar ADCs coupled with PEG4-Val-Cit,Lys(m-dPEG24)-Cit,and Val-Cit linkers.The developed ELISA methods for the calibration standards of ADC and tAb revealed a correlation be-tween serum concentrations and the OD450 values,with R2 at 1.000,and the dynamic range was 0.3-35.0 ng/mL and 0.2-22.0 ng/mL,respectively;the intra-and inter-assay accuracy bias％ranged from-12.2％to-5.2％,precision ranged from-12.4％to-1.4％,and the relative standard deviation(RSD)was less than 6.6％and 8.7％,respectively.The total error was less than 20.4％.The development and validation steps of these two assays met the acceptance criteria for all addressed validation parameters,which suggested that these can be applied to quantify MMAE-conjugated ADCs,as well as in PK studies.Furthermore,these assays can be easily adopted for development of other similar immunoassays.

Coating with flexible DNA network enhanced T-cell activation and tumor killing for adoptive cell therapy

Adoptive cell therapy (ACT) is an emerging powerful cancer immunotherapy, which includes a complex process of genetic modification, stimulation and expansion. During these

Functional Cell Receptors for Human Coronavirus / 中华检验医学杂志

Viruses infect host cells by binding to receptors on thesurface of cells. Receptor is an important factor affecting host range and interspecific transmission. In December 2019, an outbreak of unexplained pneumonia occurred in Wuhan, Hubei province. The pathogen was a new coronavirus, named 2019 NovelCoronavirus (2019-nCoV) by WHO. Angiotensin-converting enzyme 2 (ACE2) was found to be the receptor of 2019-nCoV.This review provides a brief overview of human coronavirus receptors and their applications, with a view to providing references for the tracing, cross-species transmission, epidemiological analysis and antiviral and vaccine studies of 2019-nCoV.

Effect of pulsed radiofrequency on spinal ATP-P2X4-NLRP3 signaling pathway in rats with neuropathic pain / 中华麻醉学杂志

Objective To evaluate the effect of pulsed radiofrequency (PRF) on spinal adenosine triphosphate (ATP)-P2X4-NLRP3 signaling pathway in rats with neuropathic pain.Methods Forty healthy clean-grade adult male Sprague-Dawley rats,aged 2-3 months,weighing 220-260 g,were divided into 4 groups (n =10 each) using a random number table method:sham operation group (group S),neuropathic pain group (group NP),sham PRF group (group SPRF) and PRF group.Neuropathic pain was induced by chronic constriction injury to the left sciatic nerve of anesthetized rats.Rats received PRF treatment on 7th day after establishing the model in group PRF.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured before establishing the model (T0) and at 3,7,10,14,21 and 28 days after establishing the model (T1-6).The rats were then sacrificed and the spinal cord was removed for determination of P2X4 and NLRP3 expression (by Western blot) and interleukin-1beta (IL-1β),IL-2,IL-6 and tumor necrosis factor-alpha (TNF-α) contents (by enzymelinked immunosorbent assay).Results Compared with group S,the MWT and TWL were significantly decreased at T1-6,the expression of P2X4 and NLRP3 was up-regulated,and the contents of IL-1β,IL-2,IL-6 and TNF-α were increased in NP,SPRF and PRF groups (P＜0.05).Compared with group NP and group SPRF,the MWT and MWT were significantly increased at T3-6,the expression of P2X4 and NLRP3 was down-regulated,and the contents of IL-1 β,IL-2,IL-6 and TNF-α were decreased in group PRF (P＜0.05).Conclusion The mechanism by which PRF alleviates neuropathic pain is related to inhibiting ATP-P2X4-NLRP3 signaling pathway in rats.

Regulatory effect of CLEC2D-CD161 interaction on killing capacity of decidual natural killer cells / 中华围产医学杂志

Objective@#To investigate the regulatory effect of CLEC2D-CD161 interaction on killing capacity of decidual natural killer (dNK) cells during early pregnancy and its association with the incidence of recurrent spontaneous abortion (RSA).@*Methods@#Decidua tissues were collected from normal pregnancies (n=16) and RSA cases (n=6) at 6-10 gestational weeks in the Department of Obstetrics and Gynecology of Peking University Third Hospital from October 2018 to May 2019. (1) Expressions of CLEC2D and CD161 in decidua from early pregnancy were detected using immunofluorescence. (2) Primary dNK cells were isolated from decidua from early pregnancy. dNK cells pre-treated with CD161 antibody (blocking CD161, B-CD161) were co-cultured with JEG-3 cells which were knocked-down by CLEC2D small interfering RNA (siCLEC2D), followed by killing capacity assessment of dNK cells by cytotoxicity assay and determination of expressions of related molecules by quantitive real-time polymerase chain reaction. (3) Western blot and flow cytometry were used to detect the expression of CLEC2D and CD161 in decidua tissues. Cytotoxicity assay was performed to analyze the killing capacity of dNK cells. T test was used for statistical analysis between normal and RSA cases.@*Results@#(1) CLEC2D was mainly expressed in extravillous trophoblast (EVT) cells and CD161 was mainly detected in dNK cells. CD161-positive dNK cells and CLEC2D-positive EVT cells were adjacently located in decidua tissues allowing their interaction. (2) Cytotoxicity assay suggested that CD161 blocking in dNK cells or CLEC2D knockdown in JEG-3 cells could enhance the cytotoxicity of dNK cells. The target cell lysis rates at the effector-target ratios of 40∶1, 20∶1, 10∶1 and 5∶1 in B-CD161 group were (59.12±4.56)%, (25.96±5.44)%, (13.60±8.94)% and (12.53±8.94)%, and in IgG control group were (20.01±1.96)%, (8.51±1.32)%, (3.24±0.75)% and (3.82±1.92)%, respectively. There were significant differences between the two groups at the effector-target ratios of 40∶1 (t=13.922, P<0.01) and 20∶1 (t=5.403 P<0.05), but not at 10∶1 or 5∶1 (P>0.05). The target cell lysis rates at the effector-target ratios of 40∶1, 20∶1, 10∶1 and 5∶1 in si-CLEC2D group were (43.37±2.01)%, (32.99±2.08)%, (23.47±1.36)% and (11.48±0.37)%, and in the negative control (NC) group were (15.54±1.46)%, (13.84±1.68)%, (9.94±3.01) and (5.50±0.99)%, respectively. Differences between the two groups at all effector-target ratios were statistically significant (t=19.402, 12.400, 7.093 and 9.842, all P<0.01). Moreover, the expression of dNK killing-related factor granzyme B in the siCLEC2D group was higher than that in the NC group. (3) Compared with the normal pregnancy group, the RSA group showed decreased CD161 expression and increased killing capacity of dNK cells, but no significant difference in CLEC2D expression.@*Conclusions@#At early pregnancy, CLEC2D on EVT cells can interact with CD161 on dNK cells, which inhibits the cytotoxicity of dNK cells and induces immune tolerance at the fetal-maternal interface. Decreased expression of CD161 in decidua results in increased cytotoxicity of dNK cells, which may be one of the causes of immune rejection in RSA.

Thy-1 promotes EMTprocess of livercancercells by regulating Notch1 pathway / 中国肿瘤生物治疗杂志

@# Objective: To explore the role of Thy-1 cell surface antigen（Thy-1）in promoting epithelial-mesenchymal transition (EMT) in liver cancer HepG2 and MHCC-97 cells by regulating Notch1 pathway. Methods: MHCC-97 cells with high metastatic characteristics and HepG2 cells with low metastatic characteristics were selected as subjects. WB was used to detect the expression levels of Thy-1 and Notch1 in cells. MHCC-97 and HepG2 cells were transfected with lentivirus to construct cells with high and low expression of Thy-1 protein. Cells were treated with Notch1 agonist rhNF-κB (1 gsu/ml) and Notch1 inhibitor MW167 (100 μmol/L) for 24 h respectively. Transwell assay was used to detect the effect of Thy-1 expression on cell invasion; qPCR was used to detect the effect on Notch1 mRNA expression; WB was used to detect the effect on intracellular EMT-related protein expression. Results: The expression levels of Thy-1 and Notch1 in MHCC-97 cells were higher than those in HepG2 cells (P<0.05). Thy-1 overexpressing HepG2 cells and Thy-1 low expressing MHCC-97 cells were successfully constructed. Compared with HepG2 cells, the invasion ability of Thy-1 overexpressing HepG2 cells was significantly enhanced (183.23±55.34 vs 475.78±80.37, P<0.05), vimentin expression was significantly increased (P<0.05), epithelial cadherin protein expression was significantly decreased (P<0.05), and the expression level of Notch1 mRNAwas significantly increased (P<0.05). Compared with MHCC-97 cells, the invasion ability of Thy-1 silenced MHCC97 cells was significantly decreased (543.56±77.94 vs 237.44±62.18, P<0.05), the expression of vimentin was significantly decreased (P<0.05), epithelial cadherin protein expression was significantly increased (P<0.05), and Notch1 mRNA expression level was significantly decreased (P<0.05). Treatment of liver cancer cells with Notch1 activators or inhibitors can reverse the changes caused by Thy-1 silencing or overexpression. Conclusion: Thy-1 can affect the EMT process of HepG2 and MHCC-97 cells by regulating the expression of Notch1.

Regulatory effect of CLEC2D-CD161 interaction on killing capacity of decidual natural killer cells / 中华围产医学杂志

Objective To investigate the regulatory effect of CLEC2D-CD161 interaction on killing capacity of decidual natural killer (dNK) cells during early pregnancy and its association with the incidence of recurrent spontaneous abortion (RSA). Methods Decidua tissues were collected from normal pregnancies (n=16) and RSA cases (n=6) at 6-10 gestational weeks in the Department of Obstetrics and Gynecology of Peking University Third Hospital from October 2018 to May 2019. (1) Expressions of CLEC2D and CD161 in decidua from early pregnancy were detected using immunofluorescence. (2) Primary dNK cells were isolated from decidua from early pregnancy. dNK cells pre-treated with CD161 antibody (blocking CD161, B-CD161) were co-cultured with JEG-3 cells which were knocked-down by CLEC2D small interfering RNA (siCLEC2D), followed by killing capacity assessment of dNK cells by cytotoxicity assay and determination of expressions of related molecules by quantitive real-time polymerase chain reaction. (3) Western blot and flow cytometry were used to detect the expression of CLEC2D and CD161 in decidua tissues. Cytotoxicity assay was performed to analyze the killing capacity of dNK cells. T test was used for statistical analysis between normal and RSA cases. Results (1) CLEC2D was mainly expressed in extravillous trophoblast (EVT) cells and CD161 was mainly detected in dNK cells. CD161-positive dNK cells and CLEC2D-positive EVT cells were adjacently located in decidua tissues allowing their interaction. (2) Cytotoxicity assay suggested that CD161 blocking in dNK cells or CLEC2D knockdown in JEG-3 cells could enhance the cytotoxicity of dNK cells. The target cell lysis rates at the effector-target ratios of 40 ∶ 1, 20 ∶ 1, 10 ∶ 1 and 5 ∶ 1 in B-CD161 group were (59.12±4.56)%, (25.96±5.44)%, (13.60±8.94)% and (12.53±8.94)%, and in IgG control group were (20.01±1.96)%, (8.51±1.32)%, (3.24±0.75)% and (3.82±1.92)%, respectively. There were significant differences between the two groups at the effector-target ratios of 40∶1 (t=13.922, P<0.01) and 20∶1 (t=5.403 P<0.05), but not at 10∶1 or 5∶1 (P>0.05). The target cell lysis rates at the effector-target ratios of 40∶1, 20∶1, 10∶1 and 5 ∶ 1 in si-CLEC2D group were (43.37±2.01)%, (32.99±2.08)%, (23.47±1.36)% and (11.48±0.37)%, and in the negative control (NC) group were (15.54±1.46)%, (13.84±1.68)%, (9.94±3.01) and (5.50±0.99)%, respectively. Differences between the two groups at all effector-target ratios were statistically significant (t=19.402, 12.400, 7.093 and 9.842, all P<0.01). Moreover, the expression of dNK killing-related factor granzyme B in the siCLEC2D group was higher than that in the NC group. (3) Compared with the normal pregnancy group, the RSA group showed decreased CD161 expression and increased killing capacity of dNK cells, but no significant difference in CLEC2D expression. Conclusions At early pregnancy, CLEC2D on EVT cells can interact with CD161 on dNK cells, which inhibits the cytotoxicity of dNK cells and induces immune tolerance at the fetal-maternal interface. Decreased expression of CD161 in decidua results in increased cytotoxicity of dNK cells, which may be one of the causes of immune rejection in RSA.

Oxidação da proteína dissulfeto isomerase pelo hidroperóxido de urato e as implicações sobre o endotélio vascular / Oxidation of protein disulfide isomerase by urate hydroperoxide and implications in vascular endothelium

Em condições inflamatórias do sistema vascular, altas concentrações de mieloperoxidase somada à presença do ácido úrico, sugerem a formação local do oxidante hidroperóxido de urato. A ação desse peróxido já foi demonstrada sobre glutationa e peroxirredoxinas, tornando plausível a possibilidade de que outras proteínas tiólicas também pudessem ser alvo de oxidação. A proteína dissulfeto isomerase é uma ditiol-dissulfeto oxidoredutase e chaperona, localizada principalmente no retículo endoplasmático, onde participa do enovelamento de proteínas nascentes. Além disso, um pool dessas enzimas foi identificado na superfície da célula e no meio extracelular (secretada) e parece ser especialmente importante em eventos vasculares como ativação e agregação de plaquetas, trombose e remodelamento vascular. Primeiramente, foi investigado se o hidroperóxido de urato era capaz de oxidar a PDI. Pelo ensaio do DTNB foi verificado que os tióis livres da proteína eram consumidos após reação com o peróxido e, em seguida, por nLC-MS/MS os resíduos de cisteínas dos sítios catalíticos foram identificados como os principais alvos de oxidação. Embora não tenham sido verificadas outras modificações além de dissulfetos, foi observado que o tratamento com hidroperóxido promoveu agregação e inativação da proteína. Os estudos subsequentes envolveram uma linhagem de células endoteliais (HUVECs). Análises preliminares de citotoxicidade (detecção da atividade da enzima lactato desidrogenase no sobrenadante e incorporação de sondas fluorescentes ao DNA) mostraram que tratamentos com concentrações de até 400 µM de hidroperóxido de urato não são letais às células em cultura. Usando alquilantes impermeáveis à membrana celular foi mostrado que o hidroperóxido de urato oxida não só a proteína dissulfeto isomerase, mas também proteínas tiólicas totais expressas na superfície das HUVECs. Experimentos de wound healing foram feitos para avaliação da capacidade de migração das células mediante o tratamento com hidroperóxido de urato, mas nenhuma diferença foi observada. Contudo, a incubação das células com os agentes oxidantes hidroperóxido de urato e diamida, inibidores de PDI e integrina e um alquilante de tiol, resultaram, pelo menos nos trinta primeiros minutos, em menor capacidade de adesão das células à fibronectina. Além disso, as células tratadas com hidroperóxido de urato se tornaram mais sensíveis ao destacamento da placa de cultura e apresentaram alteração na morfologia. O tratamento com o peróxido também afetou a homeostase redox das HUVECs, observado pela diminuição da razão GSH/GSSG. Finalmente foram apresentadas evidênciasindiretas de que o ácido úrico é substrato da peroxidasina, uma heme peroxidase abundantemente expressa no sistema vascular. Primeiro, pelo ensaio do Amplex Red foi observado que a presença de ácido úrico na mistura reacional resultou em menor taxa de oxidação do reagente. Depois, por LC-MS/MS, também em amostra na qual o ácido úrico estava presente, foi identificado o hidroxiisourato, álcool resultante da decomposição do hidroperóxido de urato. Todo o conjunto de dados deverá contribuir para o maior entendimento da participação do hidroperóxido de urato em processos oxidativos vasculares − especialmente a oxidação de proteínas − que pode ser um dos mecanismos responsáveis pela alteração da função endotelial e da homeostase vascular

During vascular inflammatory conditions, high amounts of myeloperoxidase added to the presence of uric acid, suggest the local formation of urate hydroperoxide. Its oxidative action has already been demonstrated on glutathione and peroxiredoxins, making plausible the possibility that other thiol proteins could also be a target for oxidation. The protein disulfide isomerase is a dithiol-disulfide oxidoreductase and chaperone, located mainly in the endoplasmic reticulum, where it is involved in the correct folding of nascent proteins. Also, a pool of these enzymes has been identified in cell surface and the extracellular (secreted) milieu and appears to be important in vascular events, such as platelet activation and aggregation, thrombosis and vascular remodeling. First, it was investigated whether urate hydroperoxide was capable of oxidizing PDI. By the DTNB assay, it was found that the free thiols of the protein were consumed after reaction with the peroxide and then, by nLC-MS / MS, the active redox cysteine residues were identified as the main oxidation targets. Although no modifications other than disulfides have been found, hydroperoxide treatment has been shown to promote protein aggregation and inactivation. Subsequent studies involved an endothelial cell line (HUVECs). Preliminary cytotoxicity analyzes (detection of lactate dehydrogenase enzyme activity in the supernatant and incorporation of fluorescent probes into DNA) have shown that treatments with concentrations up to 400 µM are not lethal to cells in culture. Then, using alkylating agents impermeable to the cell membrane, urate hydroperoxide was shown to oxidize not only PDI but also total thiol proteins expressed on HUVECs surface. Wound healing experiments were performed to evaluate cell migration after treatment with urate hydroperoxide, but no difference was observed. However, incubation of the cells with the oxidizing agents urate hydroperoxide and diamide, inhibitors of both PDI and integrin and a thiol alkylator, resulted, at least for the first thirty minutes, in reduced cell adhesion to fibronectin. In addition, cells treated with urate hydroperoxide became more sensitive to detachment from the culture dish and exhibited alterations in morphology. Treatment with the peroxide also affected the redox homeostasis of the HUVECs, observed by a decrease in the GSH / GSSG ratio. Finally, indirect evidence was presented that uric acid is a substrate of peroxidasin, a heme peroxidase abundantly expressed in the vascular system. First, with the Amplex Red assay it was observed that the presence of uric acid in the reaction mixture resulted in lower oxidation rates of the reagent. Then, by LC-MS / MS, hydroxyisourate, which is the alcohol derived from urate hydroperoxide decomposition, was also identified in samples containing uric acid. Taken together, the data presented should contribute to a better understanding of the involvement of urate hydroperoxide in vascular oxidative processes − especially protein oxidation − that may be one mechanism associated to disturbances in endothelial function and vascular homeostasis

CELL SURFACE PROTEINS OF CRYPTOCOCCUS NEOFORMANS MEDIATE ADHERENCE AND INTERNALISATION INTO MAMMALIAN CELLS

@#Cryptococcus neoformans is an encapsulated fungal pathogen that causes severe disease primarily in immunocompromised patients. Adherence and internalisation of microbial pathogens into host cells often begin with engagement of microbes to the surface receptors of host. However, the mechanisms involved remain poorly understood. In this study, we investigated the association of cell surface determinants of C. neoformans with mammalian cells. Our results showed that treatment with trypsin, but not paraformaldehyde or heat killing, could reduce host-cryptococci interaction, suggesting the involvement of cell surface proteins (CSPs) of C. neoformans in the interaction. We extended our investigations to determine the roles of CSPs during cryptococci-host cells interaction by extracting and conjugating CSPs of C. neoformans to latex beads. Conjugation of CSPs with both encapsulated and acapsular C. neoformans increased the association of latex beads with mammalian alveolar epithelial cells, alveolar macrophages and monocyte-derived macrophages. Further examination on the actin organisation of the host cells implied the involvement of actin-dependent phagocytosis in the internalisation of C. neoformans in CSP-conjugated latex beads. We hypothesised that CSPs present on the cell wall of C. neoformans mediate the adherence and actin-dependent phagocytosis of cryptococci by mammalian cells. Our results warrant further studies on the exact role of CSPs in the pathogenesis of cryptococcosis

Constitutive display of Candida antarctica lipase B on the cell surface of Aspergillus niger and regulation of its fermentation / 生物工程学报

Displaying Candida antarctica lipase B (CALB) on the cell surface of Aspergillus niger is effectively applied for the industries of food, cosmetics, pharmaceutical and so on. Displaying CALB using induced promoter of glucoamylase on the cell surface of A. niger SH-1 has some problems such as inhibiting its expression under high concentration of glucose, mycelium cleavage and decreasing enzyme activity in the later period of fermentation process. Displaying CALB manipulated by constitutive promoter from glyceraldehyde-3-phosphate dehydrogenase instead of glucoamylase on the cell surface of A. niger SH-1, called AN-GpdA, could solve the above problems effectively. Furthermore, it can not only use glucose, but also xylose as a sole carbon source. Enzyme activity of AN-GpdA using xylose for fermentation reached 1 100.28 U/g of dry cell. We also used lignocellulose such as the hydrolysate of bagasse for fermentation with good performance. The result would provide a novel strategy for the utilization of bagasse.

Scedosporium apiospermum, Scedosporium aurantiacum, Scedosporium minutisporum and Lomentospora prolificans: a comparative study of surface molecules produced by conidial and germinated conidial cells

BACKGROUND Scedosporium/Lomentospora species are opportunistic mould pathogens, presenting notable antifungal resistance. OBJECTIVES/METHODS We analysed the conidia and germinated conidia of S. apiospermum (Sap), S. aurantiacum (Sau), S. minutisporum (Smi) and L. prolificans (Lpr) by scanning electron microscopy and exposition of surface molecules by fluorescence microscopy. FINDINGS Conidia of Sap, Smi and Sau had oval, ellipsoidal and cylindrical shape, respectively, with several irregularities surrounding all surface areas, whereas Lpr conidia were rounded with a smooth surface. The germination of Sap occurred at the conidial bottom, while Smi and Sau germination primarily occurred at the centre of the conidial cell, and Lpr germination initiated at any part of the conidial surface. The staining of N-acetylglucosamine-containing molecules by fluorescein-labelled WGA primarily occurred during the germination of all studied fungi and in the conidial scars, which is the primary location of germination. Calcofluor white, which recognises the polysaccharide chitin, strongly stained the conidial cells and, to a lesser extent, the germination. Both mannose-rich glycoconjugates (evidenced by fluoresceinated-ConA) and cell wall externally located polypeptides presented distinct surface locations and expression according to both morphotypes and fungal species. In contrast, sialic acid and galactose-containing structures were not detected at fungal surfaces. MAIN CONCLUSIONS The present study demonstrated the differential production/exposition of surface molecules on distinct morphotypes of Scedosporium/Lomentospora species.

Influence of Cell Surface Hydrophobicity on Adhesion and Biofilm Formation in Candida albicans and Several Bacterial Species

The purpose of this study is to investigate the correlation of cell surface hydrophobicity (CSH) and biofilm formation or adhesion in Candida albicans (C. albicans) and several pathogenic bacteria. All of C. albicans (n=82) and 7 bacterial species (Escherichia coli, n=25; Klebsiella pneumoniae, n=33; Morganella morganii, n=21; Proteus mirabilis, n=33; Proteus vulgaris, n=12; Pseudomonas aeruginosa, n=31; Staphylococcus aureus, n=31) were isolated clinically. CSH was quantified with microbial adhesion to hydrocarbons. Biofilm formation was determined by tetrazolium salt reduction assay. Adhesion assay was performed by counting colonies after culture the microbes adhered to HeLa cells. Although high CSH-expressing bacterial species showed greater adherence to HeLa cells and larger amounts of biofilm formation on polystyrene, the significant relationships within same species were not shown. In C. albicans, however, strong positive correlations were observed between CSH and biofilm formation (r =0.708; p < 0.05) or cell adhesion (r =0.509; p < 0.05). These results suggest that hydrophobic force of bacteria may play a minor role in adhesion and biofilm formation, but CSH of C. albicans may be an important factor for adherence on surface and biofilm forming process.

Value of combined detection of serum IL-8 ,TNF-α,KL-6 and SP-D in assisted diagnosis of idiopathic pulmonary fibrosis / 国际检验医学杂志

Objective To study the clinical value of combined detection of serum interleukin(IL)-8 ,tumor necrosis factor(TNF)-α,alvedar cell surface antigen Ⅱ(KL-6) and surface protein D(SP-D) in the diagnosis of idiopathic pulmonary fibrosis(IPF) .Meth-ods Seventy three patients with IPF were selected as the research subjects ,other 73 patients with bacterial pneumonia were taken as the bacterial pneumonia group .The levels of serum IL-8 ,TNF-α,KL-6 and SP-D were detected by enzyme-linked immunosorbent assay (ELISA) .The serum levels of IL-8 ,TNF-α,KL-6 and SP-D were compared between the IPF group and bacterial pneumonia group .The sensitivity and specificity of IPF detection were compared between the 4-index combined detection and single item de-tection .Results The levels of IL-8 ,TNF-α,KL-6 and SP-D in the IPF group were significantly higher than those in the bacterial pneumonia group (P<0 .05) .The positive rate of single detection of four indexes in the IPF group was significantly higher than that in the bacterial pneumonia group (P<0 .05) .The sensitivity and specificity of the 4-index combined detection for diagnosing IPF were 90 .4% and 93 .2% respectively ,which were significantly higher than the those of single index detection (P<0 .05) .Con-clusion The combined detection of IL-8 ,TNF-α,KL-6 and SP-D has better sensitivity and specificity in IPF diagnosis compared with single detection of IL-8 ,TNF-α,KL-6 and SP-D .

Effect of regulating peroxisome proliferator-activated receptor γ on soluble endoglin expression in first-trimester trophoblasts / 中华围产医学杂志

Objective To investigate the effect of regulating peroxisome proliferator-activated receptor γγ (PPAR γ) on soluble endoglin (sEng) expression in first-trimester trophoblasts via an in vitro study.Methods Chorionic villus were collected from 20 samples of first-trimester artificial abortion in Peking University First Hospital from July 1 st to 31 st,2016.Primary culture of trophoblast cells was performed.Trophoblast cells from each sample were divided into three groups,which were PPAR γ antagonist group,PPAR γ antagonist and PPAR γ agonist group,and control group.Supematant sEng level was detected in each group by enzyme linked immunosorbent assay (ELISA).Paired-sample t test was used for statistical analysis.Results Compared with the control group,trophoblast cells in the PPAR γ antagonist group grew slower and were reduced in number.No significant difference in growth or morphology of trophoblast cells was observed between the PPAR γγ antagonist and PPAR γγ agonist group and the control group.Supernatant sEng level was elevated in the PPAR γ antagonist group,but was not significantly changed in the PPAR γ antagonist and PPAR γ agonist group as compared with that in the control group [(124.1 23.8) vs (94.0± 12.7) pg/ml,t=-4.31,P＜0.05;(87.1 ± 10.6) vs (94.0± 12.7) pg/ml,t=1.62,P=0.12).Conclusions Suppression of PPAR γ promotes sEng expression in trophoblast cells and that can be reversed by PPAR γ agonist.

Cell surface proteins play an important role in probiotic activities of Lactobacillus reuteri

BACKGROUND: Eight Lactobacillus reuteri strains, previously isolated from breast-fed human infant feces, were selected to assess the potential contribution of their surface proteins in probiotic activity. These strains were treated with 5 M LiCl to remove their surface proteins, and their tolerance to simulated stomach-duodenum passage, cell surface characteristics, auto aggregation, adhesion, and inhibition of pathogen adhesion to Caco-2 cells were compared with untreated strains. RESULTS: The survival rates, auto aggregation, and adhesion abilities of the LiCl-treated L. Reuteri strains decreased significantly (p< 0.05) compared to that of the untreated cells. The inhibition ability of selected L. reuteri strains, untreated or LiCl treated, against adherence of Escherichia coli 25922 and Salmonella typh iNCDC113 to Caco-2 was evaluated in vitro with L. reuteri ATCC55730 strain as a positive control. Among the selected eight strains of L.reuteri, LR6 showed maximum inhibition against the E. Coli ATCC25922 and S. typhiNCDC113. After treatment with 5 M LiCl to remove surface protein, the inhibition activities of the lactobacilli against pathogens decreased significantly (p< 0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis indicated thatLR6 strains had several bands with molecular weight ranging from 10 to 100 KDa, and their characterization and functions need to be confirmed. CONCLUSIONS: The results revealed that the cell surface proteins of L. reuteri play an important role in their survivability, adhesion, and competitive exclusion of pathogen to epithelial cells.

The effects of lemon essential oil,limonene and tea polyphenols on cell surface hydrophobicity and adher-ence of Streptococcus mutans / 实用口腔医学杂志

Objective:To explore the effects of the natural plant ingredients lemon essential oil(LEO),limonene(LIM)and tea poly-phenols(TP)on the cell surface hydrophobicity and adherence of Streptococcus mutans(S.mutans).Methods:S.mutans were treated by sub-minimal inhibitory concentration(MIC)levels of LEO,LIMand TP respectively.Adsorption to hexadecane was used to measure the hydrophobic interaction of S.mutans.A classical 96-cell microtitre plate production assay using crystal violet staining was employed to visualize the adherence of S.mutans to hard tissue surface.Results:LEO,LIMand TP at sub-MIC levels could inhibit the cell sur-face hydrophobicity and adherence of S.mutans in a dose-dependent manner(P <0.05).At 1 /2 MIC and 1 /20 MIC,the inhibitary effect of LEO was stronger than that of LIMand TP(P <0.05).Conclusion:LEO may possess anticariogenic potential.

Analysis of immunophenotype results in 5 patients with acute megakaryoblastic leukemia / 国际检验医学杂志

Objective To analyze the role of various blood cell surface differentiation antigens (CD) in the diagnosis and differen‐tial diagnosis of acute megakaryoblastic leukemia by detecting the immunophenotype in 5 patients with acute megakaryoblastic leu‐kemia .Methods The flow cytometry produced by the BD company and its matching reagents kits were used to detect CD in 5 pa‐tients with acute megakaryoblastic leukemia .Results All patients expressed CD41 and CD42 with the positive rate of 100% ;the lymphoid antigens ware negative in all cases ;CD13 was positive in 4 cases with the positive rate of 80% ;CD33 was positive in 3 ca‐ses with the positive rate of 60% ;CD14 and CD15 were expressed in each 1 case ,the positive rate was 20% .Conclusion The test results show that the CD41 and CD42 have an important value in the diagnosis and differential diagnosis of acute megakaryoblastic leukemia .At the same time ,the characteristic of series non‐specificityin the blood cells of the patients with acute megakaryoblas‐tic leukemia is verified again .

Expression and significance of EPCR in plasma and placenta of patients with early onset severe preeclampsia / 中华妇产科杂志

Objective To investigate the expression of endothelial protein C receptor (EPCR) and its roles in plasma and placenta of patients with early onset severe preeclampsia. Methods Sixty cases of severe preeclampsia women who delivered in Xuzhou Maternity and Child Health Care Hospital from March 2014 to February 2016, were recruited, which included 30 cases with early onset severe preeclampsia (early onset group, gestational week <34 weeks ) and 30 patients with late onset severe preeclampsia (late onset group, gestational week ≥34 weeks). Thirty cases of healthy late pregnant women at the same period (gestational week≥34 weeks) were selected as control group. Immunohistochemistry SP method was applied to detect the expression of in EPCR placenta. Reverse transcription (RT)-PCR was used to detect the expression of EPCR mRNA in placenta. ELISA method was used to detect the levels of soluble EPCR (sEPCR)level in plasma of the pregnant women of the three groups. Results The expression of EPCR in placenta mainly distributed in the membrane and cytoplasm of placental syncytiotrophoblasts and vascular endothelial cells, a few in the cell nucleus. The expression of EPCR in early onset group(57%, 17/30)was significantly lower than that in late onset group (93%, 28/30; χ2=25.165,P=0.001). The expression of EPCR in late onset group had no significant difference from that in control group (97%, 29/30;χ2=0.540,P=0.910). The expression of EPCR mRNA in placenta of early onset group(0.40±0.07)was significantly lower than that in late onset group(0.91±0.06;t=-30.044,P=0.001), while there was no statistical difference of the expression of EPCR mRNA between the late onset group and the control group (0.92±0.07;t=-0.631, P=0.538). Plasma sEPCR level in early onset group, late onset group and control group were (231 ± 11), (124±6)and(121±4)μg/L respectively, which is higher in early onset group than that in late onset group (t=48.080,P=0.001). There was no statistical difference of plasma sEPCR level between the late onset group and the control group(t=2.534,P=0.100). Conclusions The pathogenesis of early onset and late onset severe preeclampsia may be different. Decreased expression of EPCR in placenta may be associated with the pathogenesis of early onset severe preeclampsia.