123 research outputs found

    Studies on the Effects of Bioprocess Parameters and Kinetics of Rhamnolipid Production by P. aeruginosa NITT 6L

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    Biosurfactants are gaining popularity in recent times due to lower toxicity, biodegradability, environmental compatibility and activity in extreme conditions. An air isolate was isolated previously for biosurfactant production in our laboratory, and characterized and named as P. aeruginosa NITT 6L. The biosurfactant thus produced was characterized to be surface-active rhamnolipid. This paper presents the study of the influence of various bioprocess parameters such as agitation, aeration and inoculum volume on rhamnolipid production by the isolate. Kinetics of rhamnolipid production in optimized media and process conditions were investigated. The rhamnolipid production was found to be increased after nitrogen depletion during stationary phase. The maximum rhamnolipid concentration of about 7.65 g L–1 was achieved after 96 h. Logistic model was found to be satisfactory in fitting the microbial growth. Emulsification activity of the crude rhamnolipid extract with different hydrocarbons was studied. The crude extract of rhamnolipid reduced the surface tension of water from 71.4 to 27.5 mN m–1, and CMC was about 11 mg L–1. Also, the usefulness of the extracted rhamnolipid produced under optimal conditions was investigated for remediation of crude oil contaminated soil. Soil washing with 0.3 % rhamnolipid removed about 71 % of crude oil present in sand samples within 24 h

    Mcl-1 is a key regulator of the ovarian reserve

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    A majority of ovarian follicles are lost to natural death, but the disruption of factors involved in maintenance of the oocyte pool results in a further untimely follicular depletion known as premature ovarian failure. The anti-apoptotic B-cell lymphoma 2 (Bcl-2) family member myeloid cell leukemia-1 (MCL-1) has a pro-survival role in various cell types; however, its contribution to oocyte survival is unconfirmed. We present a phenotypic characterization of oocytes deficient in Mcl-1, and establish its role in maintenance of the primordial follicle (PMF) pool, growing oocyte survival and oocyte quality. Mcl-1 depletion resulted in the premature exhaustion of the ovarian reserve, characterized by early PMF loss because of activation of apoptosis. The increasingly diminished surviving cohort of growing oocytes displayed elevated markers of autophagy and mitochondrial dysfunction. Mcl-1-deficient ovulated oocytes demonstrated an increased susceptibility to cellular fragmentation with activation of the apoptotic cascade. Concomitant deletion of the pro-apoptotic Bcl-2 member Bcl-2-associated X protein (Bax) rescued the PMF phenotype and ovulated oocyte death, but did not prevent the mitochondrial dysfunction associated with Mcl-1 deficiency and could not rescue long-term breeding performance. We thus recognize MCL-1 as the essential survival factor required for conservation of the postnatal PMF pool, growing follicle survival and effective oocyte mitochondrial function

    Immunological axis of berberine in managing inflammation underlying chronic respiratory inflammatory diseases

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    © 2020 Inflammatory responses play a remarkable role in the mechanisms of acute and chronic respiratory diseases such as chronic obstructive pulmonary disease (COPD), asthma, pulmonary fibrosis and lung cancer. Currently, there is a resurgence in the use of drugs from natural sources for various ailments as potent therapeutics. Berberine, an alkaloid prominent in the Chinese traditional system of medicine has been reported to exert therapeutic properties in various diseases. Nevertheless, the number of studies focusing on the curative potential of berberine in inflammatory diseases involving the respiratory system is limited. In this review, we have attempted to discuss the reported anti-inflammatory properties of berberine that function through several pathways such as, the NF-κB, ERK1/2 and p38 MAPK pathways which affect several pro-inflammatory cytokines in the pathophysiological processes involved in chronic respiratory diseases. This review would serve to provide valuable information to researchers who work in this field and a new direction in the field of drug discovery with respect to respiratory diseases

    Constitutive Notch2 signaling in neural stem cells promotes tumorigenic features and astroglial lineage entry

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    Recent studies identified a highly tumorigenic subpopulation of glioma stem cells (GSCs) within malignant gliomas. GSCs are proposed to originate from transformed neural stem cells (NSCs). Several pathways active in NSCs, including the Notch pathway, were shown to promote proliferation and tumorigenesis in GSCs. Notch2 is highly expressed in glioblastoma multiforme (GBM), a highly malignant astrocytoma. It is therefore conceivable that increased Notch2 signaling in NSCs contributes to the formation of GBM. Here, we demonstrate that mice constitutively expressing the activated intracellular domain of Notch2 in NSCs display a hyperplasia of the neurogenic niche and reduced neuronal lineage entry. Neurospheres derived from these mice show increased proliferation, survival and resistance to apoptosis. Moreover, they preferentially differentiate into astrocytes, which are the characteristic cellular population of astrocytoma. Likewise, we show that Notch2 signaling increases proliferation and resistance to apoptosis in human GBM cell lines. Gene expression profiling of GBM patient tumor samples reveals a positive correlation of Notch2 transcripts with gene transcripts controlling anti-apoptotic processes, stemness and astrocyte fate, and a negative correlation with gene transcripts controlling proapoptotic processes and oligodendrocyte fate. Our data show that Notch2 signaling in NSCs produces features of GSCs and induces astrocytic lineage entry, consistent with a possible role in astrocytoma formation

    Liquidation of Corporation

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    Import 22/07/2015Diplomová práce se zabývá procesem likvidace obchodních společností v České republice. Cílem této práce je popsat postup likvidace obchodních společností a upozornit na některé problémy, které proces likvidace s sebou přináší, poukázat na řešení základních organizačních a ekonomických otázek související s likvidací a propojit právní a daňový pohled na likvidaci. Práce je rozdělena do čtyř kapitol. V první kapitole jsou definovány jednotlivé právní formy obchodních společností a možné způsoby jejich zrušení. Druhá kapitola se zabývá popisem likvidačního procesu, kdy jsou popsány jednotlivé kroky likvidátora v průběhu likvidace. Třetí kapitola je věnována osobě likvidátora, podmínky nutné k výkonu likvidátora, povolání likvidátora do funkce. Čtvrtá kapitola je věnována praktickým problémům spojenými s procesem likvidace.Thesis deals with the process of liquidation of corporations in the Czech Republic. The aim of this thesis is to describe the procedure of liquidation and to point out some possible problems that could occur during liquidation. The legal and tax point view of the topic will also be included. Thesis is divided into 4 main chapters. Different legal forms of the corporations and the ways of dissolution of companies are defined in the first chapter. The second chapter pursues the process of liquidation. One part of this chapter is devoted to activities of the liquidator. The person of the liquidator, including his competences and required skills, is described in the third chapter. The last chapter is focused on practical problems concerning the process of liquidation.119 - Katedra právavelmi dobř

    GSI-I (Z-LLNle-CHO) inhibits γ-secretase and the proteosome to trigger cell death in precursor-B acute lymphoblastic leukemia

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    Gamma secretase inhibitors (GSIs) comprise a growing class of compounds that interfere with the membrane-bound Notch signaling protein and its downstream intra-nuclear transcriptional targets. As GSI-I (Z-LLNle-CHO) is also a derivative of a widely used proteosome inhibitor MG-132, we hypothesized that this compound might be active in precursor-B acute lymphoblastic leukemia (ALL) cell lines and patient samples. We found that GSI-I treatment of precursor-B ALL blasts induced apoptotic cell death within 18–24 h. With confirmation using RNA and protein analyses, GSI-I blocked nuclear accumulation of cleaved Notch1 and Notch2, and inhibited Notch targets Hey2 and Myc. Microarray analyses of 207 children with high-risk precursor-B ALL demonstrate that Notch pathway expression is a common feature of these neoplasms. However, microarray studies also implicated additional transcriptional targets in GSI-I-dependent cell death, including genes in the unfolded protein response, nuclear factor-κB and p53 pathways. Z-LLNle-CHO blocks both γ-secretase and proteosome activity, inducing more robust cell death in precursor-B ALL cells than either proteosome-selective or γ-secretase-selective inhibitors alone. Using Z-LLNle-CHO in a nonobese diabetes/severe combined immunodeficiency (NOD/SCID) precursor-B ALL xenograft model, we found that GSI-I alone delayed or prevented engraftment of B-lymphoblasts in 50% of the animals comprising the experimental group, suggesting that this compound is worthy of additional testing

    The global burden of cancer attributable to risk factors, 2010-19: a systematic analysis for the Global Burden of Disease Study 2019

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    Global, regional, and national burden of colorectal cancer and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Funding: F Carvalho and E Fernandes acknowledge support from Fundação para a Ciência e a Tecnologia, I.P. (FCT), in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy i4HB; FCT/MCTES through the project UIDB/50006/2020. J Conde acknowledges the European Research Council Starting Grant (ERC-StG-2019-848325). V M Costa acknowledges the grant SFRH/BHD/110001/2015, received by Portuguese national funds through Fundação para a Ciência e Tecnologia (FCT), IP, under the Norma Transitória DL57/2016/CP1334/CT0006.proofepub_ahead_of_prin
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