The PLAG1-GDH1 Axis Promotes Anoikis Resistance and Tumor Metastasis through CamKK2-AMPK Signaling in LKB1-Deficient Lung Cancer.

Loss of LKB1 is associated with increased metastasis and poor prognosis in lung cancer, but the development of targeted agents is in its infancy. Here we report that a glutaminolytic enzyme, glutamate dehydrogenase 1 (GDH1), upregulated upon detachment via pleomorphic adenoma gene 1 (PLAG1), provides anti-anoikis and pro-metastatic signals in LKB1-deficient lung cancer. Mechanistically, the GDH1 product α-KG activates CamKK2 by enhancing its substrate AMPK binding, which contributes to energy production that confers anoikis resistance. The effect of GDH1 on AMPK is evident in LKB1-deficient lung cancer, where AMPK activation predominantly depends on CamKK2. Targeting GDH1 with R162 attenuated tumor metastasis in patient-derived xenograft model and correlation studies in lung cancer patients further validated the clinical relevance of our finding. Our study provides insight into the molecular mechanism by which GDH1-mediated metabolic reprogramming of glutaminolysis mediates lung cancer metastasis and offers a therapeutic strategy for patients with LKB1-deficient lung cancer.

Tetrameric Acetyl-CoA Acetyltransferase 1 Is Important for Tumor Growth.

Mitochondrial acetyl-CoA acetyltransferase 1 (ACAT1) regulates pyruvate dehydrogenase complex (PDC) by acetylating pyruvate dehydrogenase (PDH) and PDH phosphatase. How ACAT1 is "hijacked" to contribute to the Warburg effect in human cancer remains unclear. We found that active, tetrameric ACAT1 is commonly upregulated in cells stimulated by EGF and in diverse human cancer cells, where ACAT1 tetramers, but not monomers, are phosphorylated and stabilized by enhanced Y407 phosphorylation. Moreover, we identified arecoline hydrobromide (AH) as a covalent ACAT1 inhibitor that binds to and disrupts only ACAT1 tetramers. The resultant AH-bound ACAT1 monomers cannot reform tetramers. Inhibition of tetrameric ACAT1 by abolishing Y407 phosphorylation or AH treatment results in decreased ACAT1 activity, leading to increased PDC flux and oxidative phosphorylation with attenuated cancer cell proliferation and tumor growth. These findings provide a mechanistic understanding of how oncogenic events signal through distinct acetyltransferases to regulate cancer metabolism and suggest ACAT1 as an anti-cancer target.

Scutellaria baicalensis enhances 5-fluorouracil-based chemotherapy via inhibition of proliferative signaling pathways.

Fluoropyridine-based chemotherapy remains the most widely used treatment for colorectal cancer (CRC). In this study, we investigated the mechanism by which the natural product Scutellaria baicalensis (Huang Qin; HQ) and one of its main components baicalin enhanced 5-fluorouracil (5-FU) antitumor activity against CRC. Cell proliferation assays, cell cycle analysis, reverse-phase protein array (RPPA) analysis, immunoblot analysis, and qRT-PCR were performed to investigate the mechanism(s) of action of HQ and its active components on growth of CRC cells. HQ exhibited in vitro antiproliferative activity against drug resistant human CRC cells, against human and mouse CRC cells with different genetic backgrounds and normal human colon epithelial cells. In vivo animal models were used to document the antitumor activity of HQ and baicalin. The mechanism of growth inhibitory activity of HQ is due to inhibition of proliferative signaling pathways including the CDK-RB pathway. In addition, HQ enhanced the antitumor effects of 5-FU and capecitabine in vivo. Furthermore, we identified baicalin as an active component of HQ. The combination of baicalin and 5-FU demonstrated synergistic activity against 5-FU-resistant RKO-R10 cells. The combination significantly inhibited in vivo tumor growth greater than each treatment alone. RPPA results showed that the signaling pathway alterations in CRC cells were similar following HQ and baicalin treatment. Together, these results indicate that HQ and its component baicalin enhance the effect of 5-fluorouracil-based chemotherapy via inhibition of CDK-RB pathway. These findings may provide the rational basis for developing agents that can overcome the development of cellular drug resistance. Video Abstract.

External magnetic field have significant effects on diversity of magnetotactic bacteria in sediments from Yangtze River, Chagan Lake and Zhalong Wetland in China.

Magnetotactic bacteria (MTB) can rapidly relocate to optimal habitats by magnetotaxis, and play an important role in iron biogeochemical cycling. This study aimed to evaluate the contribution of the external magnetostatic field to the diversity of MTB in freshwater sediments from Yangtze River (Changjiang River, CJ), Chagan Lake (CGH) and Zhalong Wetland (ZL). The magnetic field intensity was tightly associated with the community richness of MTB in CJ, whereas it was closely related to the diversity of MTB in CGH and ZL (p < 0.05), elucidating a significant variation in the community composition of MTB. Magnetic exposure time appeared more significant correlation with community richness than diversity for MTB in CJ and CGH (p < 0.05), while an opposite relationship existed in ZL (p < 0.01). Herbaspirillum (93.81-96.48 %) dominated in the sediments of these surfacewatesr regardless of waterbody types, while it shifted to Magnetospirillum in ZL under 100 Gs magnetic field. The network connectivity and stability of MTB deteriorate with the increase of magnetic field intensity. Functional analysis showed that the Two-component system and ABC transporter system of MTB obviously responded to magnetic field intensity and exposure time. Our findings will pave the way to understanding the response mechanism of MTB community in freshwater sediments to the external magnetostatic field.

Potential and whole-genome sequence-based mechanism of elongated-prismatic magnetite magnetosome formation in Acidithiobacillus ferrooxidans BYM.

A magnetosome-producing bacterium Acidithiobacillus ferrooxidans BYM (At. ferrooxidans BYM) was isolated and magnetically screened. The magnetosome yield from 0.5896 to 13.1291 mg/g was achieved under different aeration rates, ferrous sulfate, ammonium sulfate, and gluconic acid concentrations at 30 â„ƒ. TEM observed 6-9 magnetosomes in size of 20-80 nm irregularly dispersed in a cell. STEM-EDXS and HRTEM-FFT implied that the elongated-prismatic magnetite magnetosomes with {110} crystal faces grown along the [111] direction. Whole-genome sequencing and annotation of BYM showed that 3.2 Mb chromosome and 47.11 kb plasmid coexisted, and 322 genes associated with iron metabolism were discovered. Ten genes shared high similarity with magnetosome genes were predicted, providing sufficient evidence for the magnetosome-producing potential of BYM. Accordingly, we first proposed a hypothetic model of magnetosome formation including vesicle formation, iron uptake and mineralization, and magnetite crystal maturation in At. ferrooxidans. These indicated that At. ferrooxidans BYM would be used as a commercial magnetosome-producing microorganism.

Visible light regulates anthocyanin synthesis via malate dehydrogenases and the ethylene signaling pathway in plum (Prunus salicina L.).

Light regulates anthocyanins synthesis in plants. Upon exposure to visible light, the inhibition of photosynthetic electron transfer significantly lowered the contents of anthocyanins and the expression levels of key genes involved in anthocyanins synthesis in plum fruit peel. Meanwhile, the expression levels of PsmMDH2 (encoding the malate dehydrogenase in mitochondria) and PschMDH (encoding the malate dehydrogenase in chloroplasts) decreased significantly. The contents of anthocyanins and the levels of the key genes involved in anthocyanin synthesis decreased significantly with the treatment of 1-MCP (an inhibitor of ethylene perception) but were enhanced by the exogenous application of ethylene. The ethylene treatment could also recover the anthocyanin synthesis capacity lowered by the photosynthetic electron transfer inhibition. Silencing PsmMDH2 and PschMDH significantly lowered the contents of anthocyanins in plum fruit. At low temperature, visible light irradiation induced anthocyanin accumulation in Arabidopsis leaves. However, the mmdh, chmdh, and etr1-1 mutants had significantly lower anthocyanins content and expressions of the key genes involved in anthocyanins synthesis compared to wild type. Overall, the present study demonstrates that both photosynthesis and respiration were involved in the regulation of anthocyanin synthesis in visible light. The visible light regulates anthocyanin synthesis by controlling the malate metabolism via MDHs and the ethylene signaling pathway.

MEK or ERK inhibition effectively abrogates emergence of acquired osimertinib resistance in the treatment of epidermal growth factor receptor-mutant lung cancers.

BACKGROUND: The majority of patients with non-small cell lung cancer (NSCLC) harboring activating epidermal growth factor receptor (EGFR) mutations respond well to osimertinib (AZD9291), a third-generation, mutation-selective EGFR inhibitor. The current study focuses on determining whether targeting MEK/ERK signaling prevents or delays the development of acquired resistance to osimertinib. METHODS: Drug effects on cell survival were determined by measuring cell number alterations. Apoptosis was assessed with flow cytometry for the detection of annexin V-positive cells and with Western blotting for protein cleavage. Alterations of proteins in cells were detected with Western blotting. Drug effects on delaying the emergence of osimertinib resistance were evaluated with colony formation in vitro and xenografts in nude mice in vivo. RESULTS: Osimertinib combined with an MEK or ERK inhibitor synergistically decreased cell survival with enhanced induction of apoptosis in EGFR-mutant NSCLC cells but not in EGFR wild-type NSCLC cells. These combinations were also very effective in killing cell clones with primary intrinsic resistance to osimertinib. Continuous and intermittent pharmacologic inhibition of MEK/ERK signaling delayed the emergence of osimertinib resistance both in vitro and in vivo. CONCLUSIONS: These results provide strong preclinical evidence in support of targeting MEK/ERK signaling as a strategy for delaying or preventing acquired resistance to osimertinib in the clinic to improve the long-term therapeutic efficacy of osimertinib. From a clinical standpoint, the data support the evaluation of an intermittent treatment schedule of osimertinib in combination with an MEK or ERK inhibitor in patients with EGFR-mutated NSCLC.

Differential Regulation of Anthocyanin Synthesis in Apple Peel under Different Sunlight Intensities.

Sunlight radiation is a main environmental factor which affects anthocyanin synthesis. To clarify the regulatory mechanism of sunlight on the synthesis of anthocyanin in apple peel, bagged apples were exposed to diverse intensities of sunlight through different shading treatments. Under an increased solar ultraviolet-B (UV-B) light intensity, the concentration of anthocyanin in apple peels was consistent with the Michaelis-Menten equation. Under lower sunlight intensities, diphenyleneiodonium chloride (DPI, an inhibitor of plasma membrane NAD(P)H oxidase) treatment increased both the concentration of cyanidin-3-glycoside and the activity of dihydroflavonol 4-reductase (DFR). However, under higher sunlight intensities, DPI treatment decreased the concentrations of cyanidin-3-glycoside and quercetin-3-glycoside, as well as the activities of DFR and UDP-glycose: flavonoid 3-O-glycosyltransferase (UFGT). These results indicate that, under low sunlight intensity, anthocyanin synthesis in apple peel was limited by the supply of the substrate cyanidin, which was regulated by the DFR activity. Nevertheless, after exposure to high sunlight intensity, the anthocyanin produced in the apple peel was dependent on UFGT activity.

Patient-derived xenografts faithfully replicated clinical outcome in a phase II co-clinical trial of arsenic trioxide in relapsed small cell lung cancer.

BACKGROUND: SCLC has limited treatment options and inadequate preclinical models. Promising activity of arsenic trioxide (ASO) recorded in conventional preclinical models of SCLC supported the clinical evaluation of ASO in patients. We assessed the efficacy of ASO in relapsed SCLC patients and in corresponding patient-derived xenografts (PDX). METHODS: Single arm, Simon 2-stage, phase II trial to enroll patients with relapsed SCLC who have failed at least one line of therapy. ASO was administered as an intravenous infusion over 1-2 h daily for 4 days in week 1 and for 2 days in weeks 2-6 of an 8-week cycle. Treatment continued until disease progression. Pretreatment tumor biopsy was employed for PDX generation through direct implantation into subcutaneous pockets of SCID mice without in vitro manipulation and serially propagated for five generations. Ex vivo efficacy of cisplatin (3 mg/kg i.p. weekly) and ASO (3.75 mg/kg i.p. every other day) was tested in PDX representative of platinum sensitive and platinum refractory SCLC. RESULTS: The best response in 17 evaluable patients was stable disease in 2 (12 %), progressive disease in 15 (88 %) patients and median time-to-progression of seven (range 1-7) weeks. PDX was successfully grown in 5 of 9 (56 %) transplanted biopsy samples. Serially-propagated PDXs preserved characteristic small cell histology and genomic stability confirmed by immunohistochemistry, short tandem repeat (STR) profiling and targeted sequencing. ASO showed in vitro cytotoxicity but lacked in vivo efficacy against SCLC PDX tumor growth. CONCLUSIONS: Cisplatin inhibited growth of PDX derived from platinum-sensitive SCLC but was ineffective against PDX from platinum-refractory SCLC. Strong concordance between clinical and ex vivo effects of ASO and cisplatin in SCLC supports the use of PDX models to prescreen promising anticancer agents prior to clinical testing in SCLC patients. Trial Registration The study was registered at http://www.clinicaltrials.gov (NCT01470248).

Paracoccus gahaiensis sp. nov. isolated from sediment of Gahai Lake, Qinghai-Tibetan Plateau, China.

An aerobic, orange-pigmented, Gram-negative, coccoid bacterium, named CUG 00006(T), was isolated from the sediment of Gahai Lake, Qinghai Province, China. This organism was alkaline and grew optimally at pH 9 and 20 °C in the presence of 4 % (w/v) NaCl. Strain CUG 00006(T) contained Q-10 as the major isoprenoid quinone and C18:1ω7c as the main fatty acids. The DNA G + C content was 67.8 mol%. The analysis of 16S rRNA gene sequences indicated that strain CUG 00006(T) was phylogenetically related to members of the genus Paracoccus, with the similarities ranging from 93.5 to 97.9 %. In particular, strain CUG 00006(T) was closely related to P. marcusii DSM 11574(T) (97.7 %), P. haeundaensis KCCM 10460(T) (97.8 %), and P. carotinifaciens IFO 16121(T) (97.7 %). On the basis of phylogenetic, physiological, and biochemical characterization, strain CUG 00006(T) is described as a new species of the genus Paracoccus, for which the name Paracoccus gahaiensis sp. nov. is proposed. The type strain is strain CUG 00006(T) (=CCTCC M 2014217(T) = KCTC 42687(T)).

Halomonas xiaochaidanensis sp. nov., isolated from a salt lake sediment.

A short-rod-shaped moderately halophilic bacterium, designated CUG 00002(T), was isolated from the sediment of Xiaochaidan salt lake in Qinghai Province, China by using R2A medium. The cells were Gram-staining negative, aerobic, forming creamy and circular colonies with diameters of 2-3 mm on R2A agar when incubated at 30 °C for 3 days. 16S rRNA gene-based phylogenetic analysis indicated that strain CUG 00002(T) belonged to the genus Halomonas in the class Gammaproteobacteria, showing highest sequence similarity of 97.1 and 96.7 % to Halomonas mongoliensis Z-7009(T) (=DSM 17332=VKM B2353) and Halomonas shengliensis SL014B-85(T) (=CGMCC 1.6444(T)=LMG 23897(T)), respectively. The predominant isoprenoid quinone was ubiquinone-9 (Q9), and the major fatty acids were C16:0, summed feature 3 (comprising C16:1 ω7c and/or C16:1 ω6c) and summed feature 8 (comprising C18:1 ω7c or C18:1 ω6c). The genomic DNA G+C content of strain CUG 00002(T) was 61.8 mol%. The above characteristics were consistent with the placement of the organism in the genus Halomonas. The level of DNA-DNA relatedness between CUG 00002(T) and its most closely related strain H. mongoliensis Z-7009(T) was 41.0 ± 1.6 %. Based on the results of phenotypic, phylogenetic and biochemical analyses, strain CUG 00002(T) represents a novel species of the genus Halomonas, for which the name Halomonas xiaochaidanensis sp. nov. is proposed. The type strain is CUG 00002(T) (=CCTCC AB 2014152(T)=KCTC 42685(T)).

Flavobacterium terriphilum sp. nov., isolated from soil.

A novel aerobic, yellow-pigmented, Gram-stain-negative, rod-shaped bacterial strain, CUG00004T, was isolated from a soil sample. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CUG00004T was a member of the genus Flavobacterium and showed high sequence similarity with Flavobacterium soli DSM 19725T (96.9 %) and Flavobacterium glaciei CGMCC 0499T (95.6 %). The level of DNA-DNA relatedness between strain CUG00004T and F. soli DSM 19725T and F. glaciei CGMCC 1.5380T was 42.5 and 43.4 %, respectively. Strain CUG00004T was moderately alkaliphilic and grew optimally at pH 8.0, at 28 °C and in the presence of 0-1 % (w/v) NaCl. This organism contained menaquinone-6 (MK-6) as the only isoprenoid quinone and iso-C15 : 0, iso-C17 : 0 3-OH, anteiso-C15 : 0 and summed feature 9 (comprising iso-C17 : 1ω9c and/or C16 : 0 10-methyl) as the major fatty acids. The DNA G+C content of strain CUG00004T was 36.3 mol%. On the basis of phylogenetic, physiological and chemotaxonomic analyses, strain CUG00004T represents a novel species, for which the name Flavobacterium terriphilum sp. nov. is proposed. The type strain is CUG00004T (=CCTCC AB 2014151T=KCTC 42876T).

[Clinical controlled trial of first-line treatment for advanced kidney cancer].

OBJECTIVE: To estimate the efficacies of different first-line treatments for advanced stage kidney cancer. METHODS: For this observation controlled trial, a total of 82 cases with advanced stage kidney cancer from 2006 to 2011 were recruited. They were divided into 3 groups and accepted gemcitabine plus interleukin-2 (IL-2) (Group A), oxaliplatin plus capecitabine (Group B) or sorafenib alone (Group C). RESULTS: Among them, 76 patients had complete data. The overall response rates of A-C groups were 39.3% (11/28), 37.0% (10/27) and 38.1% (8/21) respectively. And there was no significant difference (χ(2) = 0.029, P = 0.986). And their progression-free survival (PFS) rates were 9.1 (95%CI: 7.9 - 10.3), 7.5(95%CI: 5.5 - 9.5) and 10.9 (95%CI: 10.5 - 11.3) months respectively. And there were significant differences (P = 0.013). Average daily treatment costs were 490, 498 and 501 Chinese yuan respectively. And there was no significant difference (P = 1.240). Because of toxicity, 2 and 3 cases withdrew in Groups A and B respectively. CONCLUSION: Gemcitabine plus IL-2 and oxaliplatin plus capecitabine have similar early efficacies and tolerance profiles for the patients who can not accept sorafenib as first-line treatment.

Preparation, characterization, and in vitro release kinetics of doxorubicin-loaded magnetosomes.

The doxorubicin (DOX) was successfully coupled to the magnetosomes from Acidithiobacillus ferrooxidans (At. ferrooxidans) by genipin bridging. The parameters (magnetosome concentration, DOX concentration, genipin concentration-, and cross-link time) expected for temperature significantly influenced the coupling rate. Bacterial magnetosome-doxorubicin complexes (BMDCs) were characterized by transmission electron microscope (TEM), particle size analyzer and Fourier transform infrared spectroscopy. Results indicated that BMDCs exhibited a mean particle size of 83.98 mm and displayed a negative charge. The chemical reaction occurring between CO and NH group and the physical adsorption predominated by electrostatic interaction were found to involve in coupling. BMDCs can release 40% of DOX in simulated gastrointestinal conditions within 38 h. Kinetic models including Higuchi, Korsmeyer-Peppas, Zero order, First order, Hixon-Crowell, Baker-Lonsdale, and Weibull and Gompertz were utilized to explore the release mechanism of DOX from BMDCs. All models were found to fit well (r2 ≥ 0.8144) with the release data and the Gompertz was the best fit model (r2 = 0.9742), implying that the complex mechanisms involving Fickian and Gompertz diffusion contributed to the release. These findings suggested that magnetosomes from At. ferrooxidans have great potential applications in biomedical and clinical fields as the carrier of target drug delivery systems in the future.

Biomineralization and biotechnological applications of bacterial magnetosomes.

Magnetosomes intracellularly biomineralized by Magnetotactic bacteria (MTB) are membrane-enveloped nanoparticles of the magnetic minerals magnetite (Fe3O4) or greigite (Fe3S4). MTB thrive in oxic-anoxic interface and exhibit magnetotaxis due to the presence of magnetosomes. Because of the unique characteristic and bionavigation inspiration of magnetosomes, MTB has been a subject of study focused on by biologists, medical pharmacologists, geologists, and physicists since the discovery. We herein first briefly review the features of MTB and magnetosomes. The recent insights into the process and mechanism for magnetosome biomineralization including iron uptake, magnetosome membrane invagination, iron mineralization and magnetosome chain assembly are summarized in detail. Additionally, the current research progress in biotechnological applications of magnetosomes is also elucidated, such as drug delivery, MRI image contrast, magnetic hyperthermia, wastewater treatment, and cell separation. This review would expand our understanding of biomineralization and biotechnological applications of bacterial magnetosomes.

Overcoming acquired resistance to third-generation EGFR inhibitors by targeting activation of intrinsic apoptotic pathway through Mcl-1 inhibition, Bax activation, or both.

Treatment of EGFR-mutant non-small cell lung cancer (NSCLC) with mutation-selective third-generation EGFR-tyrosine kinase inhibitors (EGFR-TKIs) such as osimertinib has achieved remarkable success in the clinic. However, the immediate challenge is the emergence of acquired resistance, limiting the long-term remission of patients. This study suggests a novel strategy to overcome acquired resistance to osimertinib and other third-generation EGFR-TKIs through directly targeting the intrinsic apoptotic pathway. We found that osimertinib, when combined with Mcl-1 inhibition or Bax activation, synergistically decreased the survival of different osimertinib-resistant cell lines, enhanced the induction of intrinsic apoptosis, and inhibited the growth of osimertinib-resistant tumor in vivo. Interestingly, the triple-combination of osimertinib with Mcl-1 inhibition and Bax activation exhibited the most potent activity in decreasing the survival and inducing apoptosis of osimertinib-resistant cells and in suppressing the growth of osimertinib-resistant tumors. These effects were associated with increased activation of the intrinsic apoptotic pathway evidenced by augmented mitochondrial cytochrome C and Smac release. Hence, this study convincingly demonstrates a novel strategy for overcoming acquired resistance to osimertinib and other 3rd generation EGFR-TKIs by targeting activation of the intrinsic apoptotic pathway through Mcl-1 inhibition, Bax activation or both, warranting further clinical validation of this strategy.

Inflammatory Indicators and Hematological Indices in Contrast-Induced Nephropathy Among Patients Receiving Coronary Intervention: A Systematic Review and Meta-Analysis.

Strong inflammatory indicators such as C-reactive protein (CRP), high-sensitivity CRP (hsCRP), and hematological indices, including platelet to lymphocyte ratio (PLR), neutrophil to lymphocyte ratio (NLR), hematocrit (HCT), and red blood cell distribution width (RDW), may be related with contrast-induced nephropathy (CIN). Our meta-analysis aimed at exploring the relationship between these indicators and CIN incidence among patients undergoing coronary intervention. Clinical studies were retrieved from the electronic databases of PubMed, EMBASE, Google Scholar, Clinical Trials, and Science Direct from their inception to June 3, 2020. Meta-analysis was performed on pooled eligible studies. Finally, 26 studies involving 29 454 patients were included. Pooled analysis revealed that patients with higher CRP (odds ratio [OR] = 1.06, 95% CI: 1.01-1.12, P = .02), hsCRP (OR = 1.03, 95% CI: 1.01-1.06, P = .004), NLR (OR = 1.11, 95% CI: 1.01-1.20, P = .02), RDW (OR = 1.35, 95% CI: 1.19-1.53, P < .001), and lower HCT (OR = 0.94, 95% CI: 0.92-0.97, P = .003) all exhibited significantly higher CIN rates, but there was no significant association between PLR and CIN risk (OR = 1.12, 95% CI: 0.99-1.26, P = .07). Pre-angiography CRP/hsCRP and some hematological indices are associated with CIN.

Plasma S100ß and neuron-specific enolase, but not neuroglobin, are associated with early cognitive dysfunction after total arch replacement surgery: A pilot study.

ABSTRACT: To investigate whether plasma concentrations of S100ß protein, neuron-specific enolase (NSE), and neuroglobin (NGB) correlate with early postoperative cognitive dysfunction (POCD) in patients undergoing total arch replacement.This prospective study analyzed 40 patients who underwent total arch replacement combined with stented elephant trunk implantation at our hospital between March 2017 and January 2019. Cognitive function was assessed using the Mini-mental State Examination (MMSE) preoperatively, on the day after extubation and on day 7 after surgery. Plasma levels of S100ß, NSE, and NGB POCD were assayed preoperatively and at 1, 6, and 24 hours after cardiopulmonary bypass. POCD was defined as a decrease of at least 1 unit in the MMSE score from before surgery until day 7, and patients were stratified into those who experienced POCD or not. The 2 groups were compared in clinicodemographic characteristics and plasma levels of the 3 proteins.Plasma levels of all 3 biomarkers increased significantly during and after cardiopulmonary bypass. Levels of S100ß and NSE, but not NGB, were significantly higher in the 15 patients who showed POCD than in the remainder who did not. For prediction of early POCD, S100ß showed an area under the receiver operating characteristic curve (AUC) of 0.71 (95% confidence interval [CI] 0.55-0.87), sensitivity of 48%, and specificity of 87%. The corresponding values for NSE were 0.77 (95%CI 0.60-0.94), 92%, and 67%. Together, S100ß and NSE showed an AUC of 0.81 (95%CI 0.66-0.96), sensitivity of 73%, and specificity of 80%. NGB did not significantly predict early POCD (AUC 0.62, 95%CI 0.43-0.80).Plasma S100ß protein and NSE, but not NGB, may help predict early POCD after total arch replacement.

[In vivo study on the effects of intercellular adhesion operon of Staphylococcus epidermidis on the inflammation associated with bacteria-fungal mixed biofilm].

OBJECTIVE: To study the effect of intercellular adhesion (ica) operon of Staphylococcus epidermidis on the inflammation associated with mixed biofilm of Staphylococcus epidermidis and Candida albicans on endotracheal tube material in rabbits. METHODS: The standard strains of Staphylococcus epidermidis RP62A (ica operon positive, positive group) and ATCC12228 (ica operon negative, negative group) were taken to prepare a bacterial solution with a concentration of 1×10 6 CFU/mL, respectively. Then, the two bacterial solutions were mixed with the standard strain of Candida albicans ATCC10231 of the same concentration to prepare a mixed culture solution at a ratio of 1∶1, respectively. The mixed culture solution was incubated with endotracheal tube material for 24 hours. The formation of mixed biofilm on the surface of the material was observed by scanning electron microscope. Thirty New Zealand rabbits, aged 4-6 months, were divided into two groups ( n=15), and the endotracheal tube materials of the positive group and the negative group that were incubated for 24 hours were implanted beside the trachea. The body mass of rabbits in the two groups was measured before operation and at 1, 3, and 7 days after operation. At 1, 3, and 7 days after operation, the levels of interleukin 1ß (IL-1ß), IL-6, tumor necrosis factor α (TNF-α), and monocytechemotactic protein 1 (MCP-1) were detected by using an ELISA test kit. At 7 days after operation, the formation of mixed biofilm on the surface of the endotracheal tube materials was observed by scanning electron microscope, the inflammation and infiltration of tissues around the materials were observed by HE staining, and the bacterial infections in heart, lung, liver, and kidney were observed by plate colony counting method. RESULTS: Scanning electron microscope observation showed that the mixed biofilm structure was obvious in the positive group after 24 hours in vitro incubation, but no mixed biofilm formation was observed in the negative group. In vivo studies showed that there was no significant difference in body mass between the two groups before operation and at 1, 3, and 7 days after operation ( P>0.05). Compared with the negative group, the levels of MCP-1 and IL-1ß at 1 day, and the levels of IL-1ß, MCP-1, IL-6, and TNF-α at 3 and 7 days in the positive group all increased, with significant differences ( P<0.05). Scanning electron microscope observation showed that a large amount of Staphylococcus epidermis and mixed biofilm structure were observed in the positive group, and a very small amount of bacteria was observed in the negative group with no mixed biofilm structure. HE staining of surrounding tissue showed inflammatory cell infiltration in both groups, and neutrophils and lymphocytes were more in the positive group than in the negative group. There was no significant difference in the number of bacterial infections in heart and liver between the two groups ( P>0.05). The number of bacterial infections in lung and kidney in the positive group was higher than that in negative group ( P<0.05). CONCLUSION: In the mixed infection of Staphylococcus epidermidis and Candida albicans, the ica operon may strengthen the structure of the biofilm and the spread of the biofilm in vivo, leading to increased inflammatory factors, and the bacteria are difficult to remove and persist.