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41.
Averhoff Beate Kirchner Lennart Pfefferle Katharina Yaman Deniz 《Extremophiles : life under extreme conditions》2021,25(5-6):425-436
Extremophiles - Extremophilic prokaryotes live under harsh environmental conditions which require far-reaching cellular adaptations. The acquisition of novel genetic information via natural... 相似文献
42.
David S. Garbe 《Critical reviews in biochemistry and molecular biology》2013,48(5-6):319-341
How axons in the developing nervous system successfully navigate to their correct targets is a fundamental problem in neurobiology. Understanding the mechanisms that mediate axon guidance will give important insight into how the nervous system is correctly wired during development and may have implications for therapeutic approaches to developmental brain disorders and nerve regeneration. Achieving this understanding will require unraveling the molecular logic that ensures the proper expression and localization of axon guidance cues and receptors, and elucidating the signaling events that regulate the growth cone cytoskeleton in response to guidance receptor activation. Studies of axon guidance at the midline of many experimental systems, from the ventral midline of Drosophila to the vertebrate spinal cord, have led to important mechanistic insights into the complex problem of wiring the nervous system. Here we review recent advances in understanding the regulation of midline axon guidance, with a particular emphasis on the contributions made from molecular genetic studies of invertebrate model systems. 相似文献
43.
Eleonora Paparelli Sandro Parlanti Silvia Gonzali Giacomo Novi Lorenzo Mariotti Nello Ceccarelli Joost T. van Dongen Katharina K?lling Samuel C. Zeeman Pierdomenico Perata 《The Plant cell》2013,25(10):3760-3769
A plant’s eventual size depends on the integration of its genetic program with environmental cues, which vary on a daily basis. Both efficient carbon metabolism and the plant hormone gibberellin are required to guarantee optimal plant growth. Yet, little is known about the interplay between carbon metabolism and gibberellins that modulates plant growth. Here, we show that sugar starvation in Arabidopsis thaliana arising from inefficient starch metabolism at night strongly reduces the expression of ent-kaurene synthase, a key regulatory enzyme for gibberellin synthesis, the following day. Our results demonstrate that plants integrate the efficiency of photosynthesis over a period of days, which is transduced into a daily rate of gibberellin biosynthesis. This enables a plant to grow to a size that is compatible with its environment. 相似文献
44.
45.
Galliano Zanello Ashleigh Goethel Katharina Forster Kaoru Geddes Dana J. Philpott Kenneth Croitoru 《PloS one》2013,8(12)
Although the etiology of Crohn''s disease (CD) remains elusive this disease is characterized by T cell activation that leads to chronic inflammation and mucosal damage. A potential role for maladaptation between the intestinal microbiota and the mucosal immune response is suggested by the fact that mutations in the pattern recognition receptor Nod2 are associated with higher risks for developing CD. Although Nod2 deletion in CD4+ T cells has been shown to impair the induction of colitis in the murine T cell transfer model, the analysis of T cell intrinsic Nod2 function in T cell differentiation and T cell-mediated immunity is inconsistent between several studies. In addition, the role of T cell intrinsic Nod2 in regulatory T cell (Treg) development and function during colitis remain to be analyzed. In this study, we show that Nod2 expression is higher in activated/memory CD4+ T cells and its expression was inducible after T cell receptor (TCR) ligation. Nod2 stimulation with muramyl dipeptide (MDP) led to a nuclear accumulation of c-Rel NF-kB subunit. Although functionally active in CD4+ T cells, the deletion of Nod2 did not impair the induction and the prevention of colitis in the T cell transfer model. Moreover, Nod2 deletion did not affect the development of Foxp3+ Treg cells in the spleen of recipient mice and Nod2 deficient CD4 T cells expressing the OVA specific transgenic TCR were able to differentiate in Foxp3+ Treg cells after OVA feeding. In vitro, CD25+ Nod2 deficient T cells suppressed T cell proliferation as well as wild type counter parts and T cell stimulation with MDP did not affect the proliferation and the cytokine secretion of T cells. In conclusion, our data indicate that Nod2 is functional in murine CD4+ T cells but its expression is dispensable for the T cell regulation of colitis. 相似文献
46.
47.
Darshini Govindasamy Katharina Kranzer Nienke van Schaik Farzad Noubary Robin Wood Rochelle P. Walensky Kenneth A. Freedberg Ingrid V. Bassett Linda-Gail Bekker 《PloS one》2013,8(11)
Background
HIV counseling and testing may serve as an entry point for non-communicable disease screening.Objectives
To determine the yield of newly-diagnosed HIV, tuberculosis (TB) symptoms, diabetes and hypertension, and to assess CD4 count testing, linkage to care as well as correlates of linkage and barriers to care from a mobile testing unit.Methods
A mobile unit provided screening for HIV, TB symptoms, diabetes and hypertension in Cape Town, South Africa between March 2010 and September 2011. The yield of newly-diagnosed cases of these conditions was measured and clients were followed-up between January and November 2011 to assess linkage. Linkage to care was defined as accessing care within one, three or six months post-HIV diagnosis (dependent on CD4 count) and one month post-diagnosis for other conditions. Clinical and socio-demographic correlates of linkage to care were evaluated using Poisson regression and barriers to care were determined.Results
Of 9,806 clients screened, the yield of new diagnoses was: HIV (5.5%), TB suspects (10.1%), diabetes (0.8%) and hypertension (58.1%). Linkage to care for HIV-infected clients, TB suspects, diabetics and hypertensives was: 51.3%, 56.7%, 74.1% and 50.0%. Only disclosure of HIV-positive status to family members or partners (RR=2.6, 95% CI: 1.04-6.3, p=0.04) was independently associated with linkage to HIV care. The main barrier to care reported by all groups was lack of time to access a clinic.Conclusion
Screening for HIV, TB symptoms and hypertension at mobile units in South Africa has a high yield but inadequate linkage. After-hours and weekend clinics may overcome a major barrier to accessing care. 相似文献48.
The design and generation of DNA constructs is among the necessary but generally tedious tasks for molecular biologists and, typically, the cloning strategy is restricted by available restriction sites. However, increasingly sophisticated experiments require increasingly complex DNA constructs, with an intricacy that exceeds what is achievable using standard cloning procedures. Many transgenes such as inducible gene cassettes or recombination elements consist of multiple components that often require precise in-frame fusions. Here, we present an efficient protocol that facilitates the generation of these complex constructs. The golden GATEway cloning approach presented here combines two established cloning methods, namely golden Gate cloning and Multisite GatewayTM cloning. This allows efficient and seamless assembly as well as reuse of predefined DNA elements. The golden Gate cloning procedure follows clear and simple design rules and allows the assembly of multiple fragments with different sizes into one open reading frame. The final product can be directly integrated into the widely used Multisite GatewayTM cloning system, granting more flexibility when using a transgene in the context of multiple species. This adaptable and streamlined cloning procedure overcomes restrictions of “classical construct generation” and allows focusing on construct design. 相似文献
49.
Katrin Bomans Antje Lang Veronika Roedl Lisa Adolf Kyrillos Kyriosoglou Katharina Diepold Gabriele Eberl Michael M?lh?j Ulrike Strauss Christian Schmalz Rudolf Vogel Dietmar Reusch Harald Wegele Michael Wiedmann Patrick Bulau 《PloS one》2013,8(11)
Biotherapeutics are often produced in non-human host cells like Escherichia coli, yeast, and various mammalian cell lines. A major focus of any therapeutic protein purification process is to reduce host cell proteins to an acceptable low level. In this study, various E. coli host cell proteins were identified at different purifications steps by HPLC fractionation, SDS-PAGE analysis, and tryptic peptide mapping combined with online liquid chromatography mass spectrometry (LC-MS). However, no host cell proteins could be verified by direct LC-MS analysis of final drug substance material. In contrast, the application of affinity enrichment chromatography prior to comprehensive LC-MS was adequate to identify several low abundant host cell proteins at the final drug substance level. Bacterial alkaline phosphatase (BAP) was identified as being the most abundant host cell protein at several purification steps. Thus, we firstly established two different assays for enzymatic and immunological BAP monitoring using the cobas® technology. By using this strategy we were able to demonstrate an almost complete removal of BAP enzymatic activity by the established therapeutic protein purification process. In summary, the impact of fermentation, purification, and formulation conditions on host cell protein removal and biological activity can be conducted by monitoring process-specific host cell proteins in a GMP-compatible and high-throughput (> 1000 samples/day) manner. 相似文献
50.
S?s Neergaard-Petersen Ramzi Ajjan Anne-Mette Hvas Katharina Hess Sanne B?jet Larsen Steen Dalby Kristensen Erik Lerkevang Grove 《PloS one》2013,8(8)