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11.
C. Wyss 《Experimental cell research》1982,139(2)
A new culture medium, ZW, and the preparation of an extract of adult Drosophila, FX, are described, which for the first time allow the in vitro proliferation of normal Drosophila cells in the absence of undefined heterologous components. Cells from 6-hour-old Drosophila embryos can extensively differentiate and/or proliferate in ZW supplemented with FX and insulin. Cells isolated from wing discs of 90–120-hour-old larvae require ecdysterone for proliferation in ZW, in addition to FX and insulin. Explanted ovaries, testes, genital discs and intact or halved wing discs of 100-hour-old larvae grow in the same medium, at least in part due to cell proliferation. High concentrations of ecdysterone prevent differentiation and/or proliferation of cells from embryos and from wing discs and cause the lysis of most isolated imaginal disc cells grown in vitro, while cuticular differentiations are induced in wing discs and disc fragments grown in vitro. 相似文献
12.
Summary The development ofHeterodera schachtii inside roots of a cruciferous host plant grown under monoxenic conditions in an agar medium was observed with video-enhanced contrast light microscopy. One to 6 days after inoculation, roots were excised and processed for electron microscopic observations. Exudates were present on the cuticle surfaces of J 2 and early J 3 juveniles located at feeding sites. Fibrillar exudations were correlated with similar fibrillar patterns in the epicuticle, exocuticle, intermediate zone, and the striated endocuticle. Secretion vesicles assembled at many Golgi sites in the hypodermis, appeared to coalesce and form large electron translucent vesicles in the cytoplasm. We propose that secretion vesicles migrate toward the cuticle, contact the plasmalemma and transfer their contents by exocytosis or a similar mechanism to a secretion accumulation site. These contents are associated with cuticle structure and emerge as surface exudations. 相似文献
13.
M Wyss J Schlegel P James H M Eppenberger T Wallimann 《The Journal of biological chemistry》1990,265(26):15900-15908
In a recent study it has been shown that mitochondrial creatine kinase from chicken brain (Mia-CK) and heart (Mib-CK) are two distinct isoenzymes differing in ten out of the thirty N-terminal amino acids (Hossle, J.P., Schlegel, J., Wegmann, G., Wyss, M., B?hlen, P., Eppenberger, H.M., Wallimann, T., and Perriard J.C. (1988) Biochem. Biophys. Res. Commun. 151, 408-416). The present article describes the purification and biophysical characterization of the mitochondrial creatine kinase isoenzyme from chicken brain (Mia-CK). Gel permeation chromatography, direct mass measurements of individual molecules by scanning transmission electron microscopy, and analytical ultracentrifugation confirmed the existence of two different oligomeric forms, dimeric and octameric Mia-CK, with molecular masses of 85 kDa and 306-352 kDa and with sedimentation constants of 4.9-5.3 and 11.6-12.0 S, respectively. In addition, it was tested if Mia- and Mib-CK can form heterodimeric and heterooctameric molecules with subunits of other CK isoenzymes. By denaturation in urea or guanidine hydrochloride and subsequent renaturation, MiaMib-CK and surprisingly also MiaM-CK heterodimers could be generated. In contrast, no heterodimers were obtained between Mib- and M- or B-CK. Furthermore, reoctamerization of a mixture of Mia- and Mib-CK homodimers led to the formation of MiaMib-CK heterooctamers. In these heterooctamers, the Mia- and Mib-CK homodimers remained the fundamental building blocks. No subunit exchange between adjacent dimers within the heterooctamer could be observed even after storage for 3 months at 4 degrees C. The relevance of these data on the structural organization of the Mi-CK octamer and on the physiological aspects of tissue-specific isoenzyme expression are discussed. 相似文献
14.
15.
Courtney M. Tate Wayne Blosser Lisa Wyss Glenn Evans Qi Xue Yong Pan Louis Stancato 《The Journal of biological chemistry》2013,288(9):6743-6753
LY2228820 dimesylate is a highly selective small molecule inhibitor of p38α and p38β mitogen-activated protein kinases (MAPKs) that is currently under clinical investigation for human malignancies. p38 MAPK is implicated in a wide range of biological processes, in particular those that support tumorigenesis. One such process, angiogenesis, is required for tumor growth and metastasis, and many new cancer therapies are therefore directed against the tumor vasculature. Using an in vitro co-culture endothelial cord formation assay, a surrogate of angiogenesis, we investigated the role of p38 MAPK in growth factor- and tumor-driven angiogenesis using LY2228820 dimesylate treatment and by shRNA gene knockdown. p38 MAPK was activated in endothelial cells upon growth factor stimulation, with inhibition by LY2228820 dimesylate treatment causing a significant decrease in VEGF-, bFGF-, EGF-, and IL-6-induced endothelial cord formation and an even more dramatic decrease in tumor-driven cord formation. In addition to involvement in downstream cytokine signaling, p38 MAPK was important for VEGF, bFGF, EGF, IL-6, and other proangiogenic cytokine secretion in stromal and tumor cells. LY2228820 dimesylate results were substantiated using p38α MAPK-specific shRNA and shRNA against the downstream p38 MAPK effectors MAPKAPK-2 and HSP27. Using in vivo models of functional neoangiogenesis, LY2228820 dimesylate treatment reduced hemoglobin content in a plug assay and decreased VEGF-A-stimulated vascularization in a mouse ear model. Thus, p38α MAPK is implicated in tumor angiogenesis through direct tumoral effects and through reduction of proangiogenic cytokine secretion via the microenvironment. 相似文献
16.
Scharenberg A Arrigo Y Gutzwiller A Wyss U Hess HD Kreuzer M Dohme F 《Archives of animal nutrition》2007,61(5):390-405
The effects of tanniferous sainfoin on digestion and metabolism have been investigated in 12 lambs in an incomplete cross-over design (n = 6). Effects of condensed tannins (CT) were evaluated by comparing dehydrated and ensiled sainfoin treated with and without polyethylene glycol (PEG). Dehydrated and ensiled grass-clover mixtures served as controls. The lambs were fed the treatment diets, including a mineral supplement, for 21 d. During the last 7 d excreta, rumen fluid and blood were sampled. The CT of sainfoin decreased rumen fluid ammonia concentration (p < 0.001) and increased the plasma concentration mainly of essential amino acids (p < 0.001). Body retention of phosphorus, calcium and magnesium was lower with sainfoin compared to PEG-treated sainfoin (p < 0.05). Sainfoin without PEG resulted in lower digestibilities of organic matter and neutral detergent fibre than sainfoin with PEG and the grass-clover mixture (p < 0.001). Ensiling of sainfoin led to the lowest N-retention. In conclusion, the reduction in ruminal ammonia and urine-N losses by sainfoin CT did not improve N-retention. 相似文献
17.
Perini Fernando A. Macrini Thomas E. Flynn John J. Bamba Kanvaly Ni Xijun Croft Darin A. Wyss André R. 《Journal of Mammalian Evolution》2022,29(2):369-394
Journal of Mammalian Evolution - Cranial endocasts are one of the most direct tools available to obtain information about the endocranial cavity of fossil mammals, but few anatomical comparisons... 相似文献
18.
The upcoming UN Biodiversity Conference should address shortfalls of Access and Benefit Sharing systems inspired by the Nagoya Protocol to help improve sustainable use of biodiversity and equitable benefit sharing. Subject Categories: Economics, Law & Politics, Evolution & Ecology, Pharmacology & Drug DiscoveryThe 15th UN Biodiversity Conference (COP‐15) in Kunming, China, presents an opportunity for transformative change to address the biodiversity crisis. However, a lack of consensus on two key issues—mobilization of the necessary resources; and the scope and functioning of regulatory regimes that govern access to genetic resources and the sharing of benefits resulting from their use—threaten progress under the next 10‐year strategic plan of the Convention on Biological Diversity. We highlight systemic misconceptions concerning the financing of biodiversity and the burden this places on the Access and Benefit Sharing (ABS) system. We caution that unworkable ABS regulatory frameworks and conflating ABS with resource mobilization could disrupt science policies built on open access, with potentially severe ramifications for research and innovation. To resolve these tensions, we call for a recalibration of ABS to maximize the value delivered by biodiversity for all of society, including indigenous peoples and local communities. 相似文献
19.
Formation of etretinate, ethyl ester of acitretin, can be confirmed in vitro and in vivo using acitretin as the substrate. Etretinate was identified by LC/MS. The in vitro incubation was performed using rat and human liver 12,000 g supernatant, and the in vivo experiment was conducted in rats after oral dosing of acitretin. The ethyl ester formation was greatly enhanced by addition of or dosing with ethanol. 相似文献
20.
McCoy MA Senior MM Gesell JJ Ramanathan L Wyss DF 《Journal of molecular biology》2001,305(5):1099-1110
The backbone assignments, secondary structure, topology, and dynamics of the single-chain hepatitis C virus NS3 protease NS4A cofactor complex have been determined by NMR spectroscopy. Residues I34 to S181 of NS3 and the central three residues of the NS4A cofactor were assigned and the secondary structure was verified for these residues. In several X-ray structures of NS4A-bound NS3 protease, residues 1 to 28 are stabilized by crystal packing, which allows for the formation of the A0 strand and alpha0 helix. In solution, these N-terminal residues are largely unassigned and no evidence of a well-structured A0 strand or alpha0 helix was detected. NOEs between residues in the E1-F1 loop (containing D81) and the alpha1 helix (containing H57) together with the detection of a D81-H57 hydrogen bond indicate that in solution the catalytic triad (D81, H57, S139) of the protease is better ordered in the presence of the NS4A cofactor. This is consistent with the earlier crystallographic results and may explain the observed increase in catalytic activity of the enzyme due to NS4A binding. A model-free analysis of our relaxation data indicates substantial exchange rates for residues V51-D81, which comprise the upper part of the N-terminal beta-barrel. A comparison of chemical-shift differences between NS3 protease and the NS3 protease-NS4A complex shows extensive chemical-shift changes for residues V51-D81 indicating that non-local structural changes occur upon NS4A binding to the NS3 protease that are propagated well beyond the protease-cofactor interaction site. This is consistent with crystallographic data that reveal large structural rearrangements of the strand and loop regions formed by residues V51-D81 as a result of NS4A binding. The coincidence of large exchange rates for the NS3 protease-NS4A complex with chemical-shift differences due to NS4A binding suggests that residues V51-D81 of the NS3 protease NS4A complex are in slow exchange with a NS4A-free conformation of NS3 protease. 相似文献