176 research outputs found

    Optimization of expression, purification and handling anti bacteria feature protein of bovine neutrophil B-defensing BNBD2

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    زمینه و هدف: دیفنسین‎ها یکی از بزرگ‎ترین خانواده‎ی پپتید‎های ضد میکروب می‎باشند که به واسطه‎ی فعالیت بر علیه باکتری‎ها، قارچ‎ها و بسیاری از ویروس‎ها به عنوان آنتی‎بیوتیک‎های نسل جدید منفعت بسیاری دارند. هدف از این مطالعه بهینه سازی بیان، تخلیص و بررسی خاصیت ضد میکروبی پروتئین بتا دیفنسین 2 نوتروفیل‎های گاو (BNBD2) بوده است. روش بررسی: در این مطالعه‎ی تجربی-آزمایشگاهی باکتری اشرشیاکلی B‏L21(DE3) حامل وکتور pET-32a(+) که ژن BNBD2 در آن همسانه سازی شده بود جهت مطالعات مورد استفاده قرار گرفت. بیان پروتئین BNBD2 با تغییر در پارامترهای دانسیته‎ی سلولی، دمای رشد، مدت زمان القاء با استفاده از سیستم الکتروفورز عمودی (SDS-PAGE) و تست برادفورد به صورت کمی و کیفی بررسی گردید. مراحل تخلیص پروتئین نوترکیب با کمک روش شیمیایی شکافت در جایگاه فرمیک اسید و عبور از سانتریکون و اثر ضد باکتری پروتئین تخلیص شده بر چند نمونه‎ی باکتریایی گرم مثبت و گرم منفی مورد بررسی قرار گرفت. یافته ها: با استفاده از محیط کشت Luria–Bertani، شروع القاء در جذب نوری 8/0 در طول موج 600 نانومتر، غلظت یک میلی مولار ماده‎ی القاء کننده‎ی IPTG، دمای رشد 30 درجه و مدت زمان 4 ساعت پس از القاء بیشترین میزان بیان پروتئین به دست آمد. پروتئین نوترکیب با استفاده از شکافت در جایگاه فرمیک اسید و عبور از سانتریکون تخلیص گردید. نتایج آزمایش وسترن بلاتینگ نیز نشان داد که پروتئین نوترکیب به طور اختصاصی به آنتی‎بادی mouse anti-(His)6 peroxidase متصل می‎گردد. تشکیل هاله‎ی عدم رشد در محیط‎های کشت مولر هینتون آگار حاوی کشت سطحی باکتری های مورد آزمایش خاصیت ضد باکتری این پروتئین را نشان داد. نتیجه گیری: با توجه به خاصیت ضد میکروبی پروتئین BNBD2و امکان بیان پروتئین در باکتری E. coli می توان به تولید انبوه این پروتئین نوترکیب اقدام نمود

    The evolution of business relationships between technology-intensive new ventures and incumbents during the new product development process

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    This study investigates how technology-intensive new ventures shape and manage their relationships with incumbents to successfully develop new products. We undertake the dynamic views of business relationship to reveal under what conditions new ventures should emphasize more on transactional contract or alliance approach to develop their relationships with incumbents. Using longitudinal multiple case analysis, we show that transactional contract is less effective during discovery and development stages to facilitate knowledge share and collaborative learning between new ventures and incumbents. However, adopting transactional contract is essential during commercialization to strengthen the relationship, minimize the drawbacks of social bonds, and motivate both parties to engage in new projects. The results show that tensions between exchange partners are likely to increase when the incumbent is flexible to re-negotiate and share the fair benefits during the commercialization stage. Our findings provide new insights about the evolution of new ventures’ relationships with incumbents across NPD stages

    The effects of expression of different microRNAs on insulin secretion and diabetic nephropathy progression

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    MicroRNAs (miRNAs) have recently become well-known efficacious biomarkers for the diagnosis of diabetic nephropathy (DN). MiRNAs, short noncoding RNAs, are posttranscriptional regulators of gene expression, which regulate several biological cell functions, including insulin production and secretion, as well as insulin resistance in tissues. Today, the focus of the medical world is centered on the role of miRNAs as mediators for different diseases, such as DN and end-stage renal diseases (ESRD). MiRNAs are stable and detectable in human biological fluids, so their detection for early diagnosis of different diseases is highly sensitive and specific. Previous reports have shown that the alteration of miRNA profiles significantly correlates with specific stages of DN, kidney fibrosis, and renal dysfunction. This review was aimed at assessing the pathway of different miRNA expressions responsible for insulin secretion disorder and DN progression. © 2018 Wiley Periodicals, Inc

    Possible involvement of PI3K/AKT/mTOR signaling pathway in the protective effect of selegiline (deprenyl) against memory impairment following ischemia reperfusion in rat

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    Short-term cerebral ischemia led to memory dysfunction. There is a pressing need to introduce effective agents to reduce complications of the ischemia. Involvement of PI3K/AKT/mTOR signaling pathway has been determined in the neuroprotective effect of various agents. Selegiline (deprenyl) possessed neuroprotective properties. In this study global ischemia/reperfusion was established in rats. Selegiline (5 mg/kg for 7 consecutive days) administrated via intraperitoneal route. Possible involvement of PI3K/AKT/mTOR signaling pathway was evaluated using qRT-PCR, immunohistochemistry and histophatologic evaluations in the hippocampus. Spatial memory was evaluated by morris water maze (MWM). Results showed that ischemia impaired the memory and ischemic rats spent more time to find hidden platform in the MWM. Ischemia significantly decreased levels of PI3K, AKT and mTOR in the hippocampus. Histopathologic assessment revealed that the percent of dark neurons significantly increased in the CA1 area of the hippocampus of ischemic rats. Selegiline improved the memory as ischemic rats spent fewer time to find hidden platform in the MWM. Findings showed that selegiline increased the level and expression of PI3K, AKT and mTOR as well as decreased the proportion of dark neurons in the CA1 area of the pyramidal layer of the hippocampus. We concluded that selegiline, partially at least, through increases the expression of PI3K, AKT and mTOR as well as decreases the percent of dark neurons in the hippocampus could improve the memory impairment following the ischemia in rat

    Serotonin Differentially Regulates Short- and Long-Term Prediction of Rewards in the Ventral and Dorsal Striatum

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    BACKGROUND: The ability to select an action by considering both delays and amount of reward outcome is critical for maximizing long-term benefits. Although previous animal experiments on impulsivity have suggested a role of serotonin in behaviors requiring prediction of delayed rewards, the underlying neural mechanism is unclear. METHODOLOGY/PRINCIPAL FINDINGS: To elucidate the role of serotonin in the evaluation of delayed rewards, we performed a functional brain imaging experiment in which subjects chose small-immediate or large-delayed liquid rewards under dietary regulation of tryptophan, a precursor of serotonin. A model-based analysis revealed that the activity of the ventral part of the striatum was correlated with reward prediction at shorter time scales, and this correlated activity was stronger at low serotonin levels. By contrast, the activity of the dorsal part of the striatum was correlated with reward prediction at longer time scales, and this correlated activity was stronger at high serotonin levels. CONCLUSIONS/SIGNIFICANCE: Our results suggest that serotonin controls the time scale of reward prediction by differentially regulating activities within the striatum

    Reduced Incidence of Slowly Progressive Heymann Nephritis in Rats Immunized With a Modified Vaccination Technique

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    A slowly progressive Heymann nephritis (SPHN) was induced in three groups of rats by weekly injections of a chemically modified renal tubular antigen in an aqueous medium. A control group of rats received the chemically unmodified version of the antigen in an aqueous solution. One group of SPHN rats were pre- and post-treated with weekly injections of IC made up of rKF3 and rarKF3 IgM antibody at antigen excess (MIC) (immune complexes [ICs] containing sonicated ultracentrifuged [u/c] rat kidney fraction 3 [rKF3] antigen and IgM antibodies specific against the antigen, at slight antigen excess). One group of SPHN rats were post-treated with MIC 3 weeks after the induction of the disease and one group of SPHN animals received no treatment. The control group of rats received pre- and post-treatment with sonicated u/c rKF3

    Correction to: "Comparative repair capacity of knee osteochondral defects using regenerated silk fiber scaffolds and fibrin glue with/without autologous chondrocyes during 36 weeks in rabbit model (Cell and Tissue Research, (2016), 364, 3, (559-572), 10.1007/s00441-015-2355-9)

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    In this paper, figure 1 and its associated text were erroneously identical to that of another article from our group (Mobini et al., 2016, Journal of Biomaterial Application, SAGE publications). Unfortunately, copyright permission to re-use figure 1 and its related data were not requested. The authors would like to apologize for any confusion caused in this regard. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature

    A module-based analytical strategy to identify novel disease-associated genes shows an inhibitory role for interleukin 7 Receptor in allergic inflammation

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    <p>Abstract</p> <p>Background</p> <p>The identification of novel genes by high-throughput studies of complex diseases is complicated by the large number of potential genes. However, since disease-associated genes tend to interact, one solution is to arrange them in modules based on co-expression data and known gene interactions. The hypothesis of this study was that such a module could be a) found and validated in allergic disease and b) used to find and validate one ore more novel disease-associated genes.</p> <p>Results</p> <p>To test these hypotheses integrated analysis of a large number of gene expression microarray experiments from different forms of allergy was performed. This led to the identification of an experimentally validated reference gene that was used to construct a module of co-expressed and interacting genes. This module was validated in an independent material, by replicating the expression changes in allergen-challenged CD4<sup>+ </sup>cells. Moreover, the changes were reversed following treatment with corticosteroids. The module contained several novel disease-associated genes, of which the one with the highest number of interactions with known disease genes, <it>IL7R</it>, was selected for further validation. The expression levels of <it>IL7R </it>in allergen challenged CD4<sup>+ </sup>cells decreased following challenge but increased after treatment. This suggested an inhibitory role, which was confirmed by functional studies.</p> <p>Conclusion</p> <p>We propose that a module-based analytical strategy is generally applicable to find novel genes in complex diseases.</p

    Sterol Intermediates of Cholesterol Biosynthesis Inhibit Hair Growth and Trigger an Innate Immune Response in Cicatricial Alopecia

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    Primary cicatricial alopecia (PCA) is a group of inflammatory hair disorders that cause scarring and permanent hair loss. Previous studies have implicated PPARγ, a transcription factor that integrates lipogenic and inflammatory signals, in the pathogenesis of PCA. However, it is unknown what triggers the inflammatory response in these disorders, whether the inflammation is a primary or secondary event in disease pathogenesis, and whether the inflammatory reaction reflects an autoimmune process. In this paper, we show that the cholesterol biosynthetic pathway is impaired in the skin and hair follicles of PCA patients. Treatment of hair follicle cells with BM15766, a cholesterol biosynthesis inhibitor, or 7-dehydrocholesterol (7-DHC), a sterol precursor, stimulates the expression of pro-inflammatory chemokine genes. Painting of mouse skin with 7-DHC or BM15766 inhibits hair growth, causes follicular plugging and induces the infiltration of inflammatory cells into the interfollicular dermis. Our results demonstrate that cholesterologenic changes within hair follicle cells trigger an innate immune response that is associated with the induction of toll-like receptor (TLR) and interferon (IFN) gene expression, and the recruitment of macrophages that surround the hair follicles and initiate their destruction. These findings reveal a previously unsuspected role for cholesterol precursors in PCA pathogenesis and identify a novel link between sterols and inflammation that may prove transformative in the diagnosis and treatment of these disorders
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