136 research outputs found

    Oxidative damage from repeated tissue isolation for subculturing causes degeneration in Volvariella volvacea

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    The fungal fruiting body is the organized mycelium. Tissue isolation and mycelium succession are common methods of fungal species purification and rejuvenation in the production of edible mushrooms. However, repeated succession increases strain degeneration. In this study, we examined the effect of repeated tissue isolation from Volvariella volvacea fruitbodies on the occurrence of degeneration. The results showed that less than four times in succession improved production capacity, however, after 12 successions, the traits indicating strain degeneration were apparent. For instance, the density of aerophytic hyphae, hyphal growth rate and hyphal biomass were gradually reduced, while the hyphae branching was increased. Also, other degenerative traits such as prolonged production cycles and decreased biological efficiency became evident. In particular, after 19 successions, the strain degeneration became so severe no fruiting bodies were produces anymore. Meanwhile, with the increase in successions, the antioxidant enzyme activity decreased, reactive oxygen species (ROS) increased, the number of nuclei decreased, and the mitochondrial membrane potential decreased along with morphological changes in the mitochondria. This study showed that repeated tissue isolation increased oxidative damage in the succession strain due to the accumulation of ROS, causing cellular senescence, in turn, degeneration in V. volvacea strain

    Biomass fuel usage for cooking and frailty among older adults in China: a population-based cohort study

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    BackgroundAlthough outdoor air pollution is reported to have a negative effect on frailty, evidence involving household air pollution is sparse.MethodsA cohort study on older participants aged ≥65 years from the Chinese Longitudinal Healthy Longevity Survey was conducted between 2011/2012 and 2014. Household cooking fuel types were determined by self-reported questionaries, and were dichotomized into clean or biomass fuels. The frailty status was evaluated via a 46-item frailty index (FI) and the FRAIL scale, respectively. Frailty was identified if FI >0.21 or FRAIL score ≥3. Cox proportional hazards models were employed to examine the relationship between cooking fuels and incident frailty. And the effects of swapping cooking fuels on frailty risk were also explored.ResultsAmong 4,643 participants (mean age at baseline 80.9 ± 9.6 years, 53.7% male) totaling 11,340 person-years, 923 (19.9%) incident frailty was identified using FI. Compared to clean fuels, cooking with biomass fuels was intricately linked to a 23% rise in frailty risk (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.06–1.43). A similar association was detected between biomass cooking fuels and frailty measured by the FRAIL scale (HR 1.24, 95% CI 1.04–1.50). Sensitive analyses supported the independent relationship between biomass fuels and frailty. Stratified analyses revealed that the frailty risk was higher among town residents (HR 1.44, 95% CI 1.13–1.84) and participants not exercising regularly (HR 1.35, 95% CI 1.11–1.64). In comparison with persistent biomass fuels usage, switching to clean fuels had a trend to reduce the frailty risk, and the opposite effect was observed when swapping from clean to biomass fuels.ConclusionCooking with biomass fuels was associated with an increased frailty risk in older adults, especially amongst those living in town and those lacking regular exercise. More studies are needed to confirm our findings and to evaluate the potential benefits of reducing indoor biomass fuel usage

    High-expression of the innate-immune related gene UNC93B1 predicts inferior outcomes in acute myeloid leukemia

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    Acute myeloid leukemia (AML) is a heterogeneous hematological malignancy with dismal prognosis. Identification of better biomarkers remained a priority to improve established stratification and guide therapeutic decisions. Therefore, we extracted the RNA sequence data and clinical characteristics of AML from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression database (GTEx) to identify the key factors for prognosis. We found UNC93B1 was highly expressed in AML patients and significantly linked to poor clinical features (p < 0.05). We further validated the high expression of UNC93B1 in another independent AML cohort from GEO datasets (p < 0.001) and performed quantitative PCR of patient samples to confirm the overexpression of UNC93B1 in AML (p < 0.005). Moreover, we discovered high level of UNC93B1 was an independent prognostic factor for poorer outcome both in univariate analysis and multivariate regression (p < 0.001). Then we built a nomogram model based on UNC93B1 expression, age, FAB subtype and cytogenetic risk, the concordance index of which for predicting overall survival was 0.729 (p < 0.001). Time-dependent ROC analysis for predicting survival outcome at different time points by UNC93B1 showed the cumulative 2-year survival rate was 43.7%, and 5-year survival rate was 21.9%. The differentially expressed genes (DEGs) between two groups divided by UNC93B1 expression level were enriched in innate immune signaling and metabolic process pathway. Protein–protein interaction (PPI) network indicated four hub genes (S100A9, CCR1, MRC1 and CD1C) interacted with UNC93B1, three of which were also significantly linked to inferior outcome. Furthermore, we discovered high UNC93B1 tended to be infiltrated by innate immune cells, including Macrophages, Dendritic cells, Neutrophils, Eosinophils, and NK CD56dim cells. We also found UNC93B1 had a significantly positive correlation with CD14, CD68 and almost all Toll-like receptors. Finally, we revealed negatively correlated expression of UNC93B1 and BCL2 in AML and conjectured that high-UNC93B1 monocytic AML is more resistant to venetoclax. And we found high MCL-1 expression compensated for BCL-2 loss, thus, we proposed MCL-1 inhibitor might overcome the resistance of venetoclax in AML. Altogether, our findings demonstrated the utility of UNC93B1 as a powerful poor prognostic predictor and alternative therapeutic target

    Integrative Analyses of Long Non-coding RNA and mRNA Involved in Piglet Ileum Immune Response to Clostridium perfringens Type C Infection

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    Long non-coding RNAs (lncRNAs) have been shown to play important roles in regulating host immune and inflammatory responses to bacterial infection. Infection with Clostridium perfringens (C. perfringens), a food-borne zoonotic pathogen, can lead to a series of inflammatory diseases in human and piglet, greatly challenging the healthy development of global pig industry. However, the roles of lncRNAs involved in piglet immune response against C. perfringens type C infection remain unknown. In this study, the regulatory functions of ileum lncRNAs and mRNAs were investigated in piglet immune response to C. perfringens type C infection among resistance (IR), susceptibility (IS) and sham-inoculation (control, IC) groups. A total of 480 lncRNAs and 3,669 mRNAs were significantly differentially expressed, the differentially expressed lncRNAs and mRNAs in the IR and IS groups were enriched in various pathways of ABC transporters, olfactory transduction, PPAR signaling pathway, chemokine signaling pathway and Toll-like receptor signaling pathway, involving in regulating piglet immune responses and resistance during infection. There were 212 lncRNAs and 505 target mRNAs found to have important association with C. perfringens infectious diseases, furthermore, 25 dysregulated lncRNAs corresponding to 13 immune-related target mRNAs were identified to play potential roles in defense against bacterial infection. In conclusion, the results improve our understanding on the characteristics of lncRNAs and mRNAs on regulating host immune response against C. perfringens type C infection, which will provide a reference for future research into exploring C. perfringens-related diseases in human

    Detoxification Center-Based Sampling Missed a Subgroup of Higher Risk Drug Users, a Case from Guangdong, China

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    BACKGROUND: Injection drug use remains among the most important HIV transmission risk in China. Representativeness of drug users sampled from detoxification centers is questionable. A respondent driven sampling survey was conducted to compare the results with those from the detoxification center in the same city. METHODS: In 2008, two independent surveys were conducted in Dongguan, China, one for community-based drug users using respondent driven sampling and the other for drug users in a compulsory detoxification center as routine sentinel surveillance. Demographic and behavioral information were collected using the same structured questionnaire. Intravenous blood samples were collected to measure antibodies to HIV-1, and syphilis. RESULTS: Compared to those 400 drug users recruited from the detoxification center, the 303 community-based drug users had higher HIV prevalence (14.7% versus 4.0%, P = 0.04), lower syphilis prevalence (4.7% versus 10.8%, P = 0.07), higher proportion of injection drug use (83.9% versus 60.2%, P = 0.01) and syringe sharing (47.8% versus 36.3%, P = 0.10), more likely to be separated (12.4% versus 3.8%, P = 0.01) and being migrants from Guangxi province (31.4% versus 18.0%, P = 0.09), more engaging in commercial sex (64.4% versus 52.5%, P = 0.04). HIV prevalence and rate of syringe sharing were consistently higher among drug users from Guangxi. CONCLUSIONS: Detoxification center-based sampling missed a subgroup with higher HIV prevalence and higher rate of injection drug use. While detoxification center-based sampled can be used to monitor the trend of HIV prevalence and risk behaviors over time, periodic community-based sampling is still necessary to avoid possible systematic error in detoxification center-based samples

    Anti-HIV-1 Activity of a New Scorpion Venom Peptide Derivative Kn2-7

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    For over 30 years, HIV/AIDS has wreaked havoc in the world. In the absence of an effective vaccine for HIV, development of new anti-HIV agents is urgently needed. We previously identified the antiviral activities of the scorpion-venom-peptide-derived mucroporin-M1 for three RNA viruses (measles viruses, SARS-CoV, and H5N1). In this investigation, a panel of scorpion venom peptides and their derivatives were designed and chosen for assessment of their anti-HIV activities. A new scorpion venom peptide derivative Kn2-7 was identified as the most potent anti-HIV-1 peptide by screening assays with an EC50 value of 2.76 µg/ml (1.65 µM) and showed low cytotoxicity to host cells with a selective index (SI) of 13.93. Kn2-7 could inhibit all members of a standard reference panel of HIV-1 subtype B pseudotyped virus (PV) with CCR5-tropic and CXCR4-tropic NL4-3 PV strain. Furthermore, it also inhibited a CXCR4-tropic replication-competent strain of HIV-1 subtype B virus. Binding assay of Kn2-7 to HIV-1 PV by Octet Red system suggested the anti-HIV-1 activity was correlated with a direct interaction between Kn2-7 and HIV-1 envelope. These results demonstrated that peptide Kn2-7 could inhibit HIV-1 by direct interaction with viral particle and may become a promising candidate compound for further development of microbicide against HIV-1

    Molecular mechanisms of shikonin and its derivatives in cancer therapy

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    The identification of molecular processes involved in cancer development and prognosis opened avenues for targeted therapies, which made treatment more tumor-specific and less toxic than conventional therapies. One important example is the epidermal growth factor receptor (EGFR) and EGFR-specific inhibitors (i.e. erlotinib). However, challenges such as drug resistance still remain in targeted therapies. Therefore, novel candidate compounds and new strategies are needed for improvement of therapy efficacy. Shikonin and its derivatives are cytotoxic constituents in traditional Chinese herbal medicine Zicao (Lithospermum erythrorhizin). In this study, we investigated the molecular mechanisms underlying the anti-cancer effects of shikonin and its derivatives in glioblastoma cells and leukemia cells. Most of shikonin derivatives showed strong cytotoxicity towards erlotinib-resistant glioblastoma cells, especially U87MG.ΔEGFR cells which overexpressed a deletion-activated EGFR (ΔEGFR). Moreover, shikonin and some derivatives worked synergistically with erlotinib in killing EGFR-overexpressing cells. Combination treatment with shikonin and erlotinib overcame the drug resistance of these cells to erlotinib. Western blotting analysis revealed that shikonin inhibited ΔEGFR phosphorylation and led to corresponding decreases in phosphorylation of EGFR downstream molecules. By means of Loewe additivity and Bliss independence drug interaction models, we found erlotinb and shikonin or its derivatives corporately suppressed ΔEGFR phosphorylation. We believed this to be a main mechanism responsible for their synergism in U87MG.ΔEGFR cells. In leukemia cells, which did not express EGFR, shikonin and its derivatives exhibited even greater cytotoxicity, suggesting the existence of other mechanisms. Microarray-based gene expression analysis uncovered the transcription factor c-MYC as the commonly deregulated molecule by shikonin and its derivatives. As validated by Western blotting analysis, DNA-binding assays and molecular docking, shikonin and its derivatives bound and inhibited c-MYC. Furthermore, the deregulation of ERK, JNK MAPK and AKT activity was closely associated with the reduction of c-MYC, indicating the involvement of these signaling molecules in shikonin-triggered c-MYC inactivation. In conclusion, the inhibition of EGFR signaling, synergism with erlotinib and targeting of c-MYC illustrate the multi-targeted feature of natural naphthoquinones such as shikonin and derivatives. This may open attractive possibilities for their use in a molecular targeted cancer therapy.Die Identifizierung molekularer Prozesse der Krebsentstehung und -prognose eröffnet zahlrahlreiche Möglichkeiten für zielgerichtete Therapien, welche Tumor-spezifischer und weniger toxisch sind als konventionelle Methoden. Ein wichtiges Beispiel ist der epidermale Wachstumsfaktor-Rezeptor (EGFR) und EGFR-spezifische Hemmstoffe (z.B. Erlotinib). Jedoch bleibt das Problem der Medikamentenresistenz auch bei zielgerichteten Therapien bestehen. Deshalb weden neue Kandidatensubstanzen und neue Strategien zur Verbesserung der Therapieeffizienz benötigt. Shikonin und seine Derivate sind zytotoxische Inhaltsstoffe der traditional chinesischen Heilpflanze Zicao (Lithospermum erythrorhizon). In dieser Dissertation untersuchten wir die zugrundeliegenden molekularen Mechanismen der antitumoralen Wirkung von Shikonin und seinen Derivaten in Glioblastom- und Leukämiezellen. Die meisten Shikoninderivate zeigten eine starke Zytotoxizität gegenüber Erlotinib-resistenten Glioblastomzellen-besonders gegenüber U87.MGΔEGFR Zellen, welche einen deletions-aktivierten EGFR (ΔEGFR) exprimierten. Darüber hinaus wirkten Shikonin und einige Derivate zusammen mit Erlotinib synergistisch bei der Abtötung von U87.MGΔEGFR Zellen. Die Kombinationsbehandlung mit Shikonin und Erlotinib überwand die Resistenz dieser Zellen zu Erlotinib. Western-Blot Analysen zeigten, dass Shikonin die ΔEGFR-Phosphorylierung hemmte und dass die Phosphorylierung EGFR-nachgeschalteter Moleküle ebenfalls sank. Mittels Loewe Additivitäts- und Bliss unabhängige Medikamenten-Interaktions-Modellen fanden wir, dass Erlotinib und Shikonin (bzw. seine Derivate) gemeinsam die ΔEGFR-Phosphorylierung hemmten. Wir glauben, dass das der Hauptmechanismus ist, welcher für den Synergismus in U87.MGΔEGFR Zellen verantwortlich ist. In Leukämiezellen, welche kein EGFR exprimieren, wiesen Shikonin und seine Derivate sogar noch höhere Zytotoxizitäten auf, was auf die Existenz anderer Mechanimen hindeutet. Microarray-basierte Genexpressionsanalysen deckten den Transkriptionsfaktor c-MYC als gemeisam dereguliertes Molekül durch Shikonin und seine Detivate auf. Wie durch Western-Blot Analysen, DNA-Bindungs-Assays und molekulares Docking bestätigt wurde, banden und hemmten Shikonin und Derivate c-MYC. Weiterhin war eine Deregulation der ERK, JNK, MAPK und AKT Aktivität eng assoziiert mit einer c-MYC Reduktion. Dies weist auf eine Einbindung dieser Signalmoleküle in die Shikonin-gesteuerte c-MYC Inaktivierung hin. Zusammenfassend veranschaulicht die Hemmung von EGFR-Signalwegen, der Synergismus mit Erlotinib sowie die zielgerichtete Bindung an c-MYC die multi-Target Eigenschaften natürlich vorkommender Naphthochinone wie Shikonin und seine Derivate. Dies eröffnet attraktive Möglichkeiten für deren Gebrauch in der molekularen, zielgerichteten Krebstherapie

    Parameter identifiability of ductile fracture criterion for DP steels using bi-level reduced surrogate model

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    Generally, a large number of fracture tests are required to characterize the material parameters of the modified Mohr-Coulomb (MMC) fracture criterion. It takes enormous amount of time and expenses to prepare specimens and analyze experimental measurements. However, manufacturing industries are keen to seek fast and cost effective approaches. Therefore, a bi-level reduced surrogate model has been proposed as an alternative method for the parameter identification. Using this approach, the identification process becomes feasible and it requires only a limited number of experimental tests. The surrogate model is used in the current framework to empirically capture the non-linear evolution of material parameters for the fracture onset under the uniaxial loading condition. It assembles local critical elements associated with the global 3D finite element (FE) models. The surrogate model of fracture strain is constructed using Diffuse Approximation and the local elements to identify the unknown parameters. Then, global fracture simulations which consider the identified parameters, are preformed to update the target fracture strain and to compute the corresponding failure onset displacement. Satisfactory results are obtained by adopting the concept of successive Design of Experiments (DOE). The identification protocol is validated, and it is capable of calibrating ductile fracture parameters for different DP steels. Finally, a parametric study is performed to analyze the sensitivity of each free parameter and the influence of the used polynomial basis within the identification approach

    Profile of Pancreatic and Ileal Microbiota in Experimental Acute Pancreatitis

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    Acute pancreatitis (AP) is accompanied by gut microbiota dysbiosis. However, the composition of the pancreatic and ileal microbiota associated with AP is still unknown. This study aims to examine the alterations in the microbial composition of the pancreas and ileum in the context of experimental acute pancreatitis, as well as explore the potential interplay between these two regions. Methods: Caerulein (CAE), caerulein+lipopolysaccharide (CAE+LPS), and L-arginine (ARG) were used to induce AP in mice. The pancreas and ileum were collected for histological study and bacterial 16S rRNA gene sequencing. The results showed microbial structural segregation between the AP and control groups and between ARG and the two CAE groups (CAE, CAE+LPS) in the pancreas and ileum. Taxonomic analysis at the genus level and linear discriminant analysis effect size (LEfSe) at the operational taxonomic units (OTUs) level illustrated that AP mice exhibited a marked increase in the relative abundance of Muribaculaceae and a decrease in that of Dietzia both in the pancreas and ileum, and a reduction in Bifidobacterium only in the ileum; in addition, Roseburia was enriched in the two CAE groups in the pancreas and/or ileum, while Escherichia–Shigella expanded in the pancreas of the ARG group. Spearman correlation analysis between pancreatic and ileal microbiota revealed that the abundance of Muribaculaceae and Dietzia in the pancreas was related to that in the ileum. These findings demonstrated that caerulein and L-arginine differentially disturbed the pancreatic and ileal microbiota when inducing AP. Furthermore, these findings provide preliminary support for an association between the microbiota of the pancreas and ileum, which could be caused by AP-induced microbial translocation
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