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Hannelore Hemstedt 《Zoomorphology》1969,66(1):51-72
An electron microscopic examination of the KOSHEWNIKOW gland of the honeybee showed that the origin of the draining ductule extended into the gland cell through an invagination without actual cytoplasmic connection being made. The structure of the wall of the dendritic apical ramifications of the duct cell is very loose where it is in juxtaposition to the microvilli of the wall of the gland cell. In contrast, the rest of the duct wall is very dense.
Gekürzte Dissertation der Fakultät für Chemie, Biologic, Geologic und Mineralogio der Technischen Hochschule Darmstadt; D I7. Danken möchte ich meinem verstorbenen Lehrer, Herrn Prof. Dr. W. Luther, Herrn Prof. Dr. D. B. E. Magnus and ganz besonders Herrn Prof. Dr. K. E. Wohlfarth-Bottermann für seine hilfsbereite Beratung in Fragen der Elektronenmikroskopie. 相似文献
Gekürzte Dissertation der Fakultät für Chemie, Biologic, Geologic und Mineralogio der Technischen Hochschule Darmstadt; D I7. Danken möchte ich meinem verstorbenen Lehrer, Herrn Prof. Dr. W. Luther, Herrn Prof. Dr. D. B. E. Magnus and ganz besonders Herrn Prof. Dr. K. E. Wohlfarth-Bottermann für seine hilfsbereite Beratung in Fragen der Elektronenmikroskopie. 相似文献
3.
In order to understand better the physiological adaption of creosotebush (Larrea divaricata Cav.) to drought conditions, its carbohydrate and nitrogen metabolism after a 7-day desiccation period under controlled conditions were studied. Although fructose was not significantly altered in the leaves of desiccated plants, as compared to those maintained under normal moisture conditions, both glucose and sucrose were significantly reduced. Total amino acids more than doubled under moisture stress, the increase being predominantly due to proline, phenylalanine, and glutamic acid. Significant increases also occurred in alanine, arginine, histidine, isoleucine, and valine. Increases or decreases in other amino acids were not significant. These stress-induced changes in certain amino acids are considered in relationship to protein hydrolysis, to accumulation of nitrogen degradation products translocated from the roots, and to the possible function of specific amino acids (e.g., proline) in NH3+ storage. 相似文献
4.
Thorsten Wöhl Hannelore Klier Hubert Ammer Friedrich Lottspeich Viktor Magdolen 《Molecular & general genetics : MGG》1993,241(3-4):305-311
In Saccharomyces cerevisiae, hypusine-containing proteins are encoded by two closely related genes, HYP1 and HYP2, which are regulated reciprocally by oxygen and heme. We have purified the aerobically expressed hypusine-containing proteins from yeast. The three proteins detected (two isoforms, which differ in their pI values, and a degradation product thereof, lacking the N-terminal 10 amino acid residues) are all encoded by HYP2. The N-terminus of both isoforms is formed by acetylation of a serine residue after cleavage of the first methionine. Cells mutant for hyp2 are unable to grow aerobically. However, under anaerobic conditions these mutants display no obvious phenotype, presumably because the strictly anaerobically expressed HYPI gene product (Hyp1p) is present. This implies that Hyp1p and Hyp2p fulfill very similar functions. In fact, Hyp1p can substitute for Hyp2p under aerobic conditions, when expressed under the control of the GAL1 promoter in hyp2 mutant cells.Abbreviations
HYP1 and HYP2
S. cerevisiae genes encoding hypusine-containing protein Hyplp and Hyp2p, respectively 相似文献
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Nils Offen Johannes Flemming Hares Kamawal Ruhel Ahmad Wanja Wolber Christian Geis Holm Zaehres Hans R Sch?ler Hannelore Ehrenreich Albrecht M Müller Anna-Leena Sirén 《Molecular medicine (Cambridge, Mass.)》2013,19(1):399-408
Induced cell fate changes by reprogramming of somatic cells offers an efficient strategy to generate autologous pluripotent stem (iPS) cells from any adult cell type. The potential of iPS cells to differentiate into various cell types is well established, however the efficiency to produce functional neurons from iPS cells remains modest. Here, we generated panneural progenitor cells (pNPCs) from mouse iPS cells and investigated the effect of the neurotrophic growth factor erythropoietin (EPO) on their survival, proliferation and neurodifferentiation. Under neural differentiation conditions, iPS-derived pNPCs gave rise to microtubule-associated protein-2 positive neuronlike cells (34% to 43%) and platelet-derived growth factor receptor positive oligodendrocytelike cells (21% to 25%) while less than 1% of the cells expressed the astrocytic marker glial fibrillary acidic protein. Neuronlike cells generated action potentials and developed active presynaptic terminals. The pNPCs expressed EPO receptor (EPOR) mRNA and displayed functional EPOR signaling. In proliferating cultures, EPO (0.1–3 U/mL) slightly improved pNPC survival but reduced cell proliferation and neurosphere formation in a concentration-dependent manner. In differentiating cultures EPO facilitated neurodifferentiation as assessed by the increased number of β-III-tubulin positive neurons. Our results show that EPO inhibits iPS pNPC self-renewal and promotes neurogenesis. 相似文献
8.
Elena Helk Hannah Bernin Thomas Ernst Harald Ittrich Thomas Jacobs Joerg Heeren Frank Tacke Egbert Tannich Hannelore Lotter 《PLoS pathogens》2013,9(1)
Amebic liver abscess (ALA) is a focal destruction of liver tissue due to infection by the protozoan parasite Entamoeba histolytica (E. histolytica). Host tissue damage is attributed mainly to parasite pathogenicity factors, but massive early accumulation of mononuclear cells, including neutrophils, inflammatory monocytes and macrophages, at the site of infection raises the question of whether these cells also contribute to tissue damage. Using highly selective depletion strategies and cell-specific knockout mice, the relative contribution of innate immune cell populations to liver destruction during amebic infection was investigated. Neutrophils were not required for amebic infection nor did they appear to be substantially involved in tissue damage. In contrast, Kupffer cells and inflammatory monocytes contributed substantially to liver destruction during ALA, and tissue damage was mediated primarily by TNFα. These data indicate that besides direct antiparasitic drugs, modulating innate immune responses may potentially be beneficial in limiting ALA pathogenesis. 相似文献
9.
Cyril F. M. Marsaux Carlos Celis-Morales Jettie Hoonhout Arjan Claassen Annelies Goris Hannah Forster Rosalind Fallaize Anna L. Macready Santiago Navas-Carretero Silvia Kolossa Marianne C. Walsh Christina-Paulina Lambrinou Yannis Manios Magdalena Godlewska Iwona Traczyk Julie A. Lovegrove J. Alfredo Martinez Hannelore Daniel Mike Gibney John C. Mathers Wim H. M. Saris 《PloS one》2016,11(3)
Background
Comparisons of objectively measured physical activity (PA) between residents of European countries measured concurrently with the same protocol are lacking. We aimed to compare PA between the seven European countries involved in the Food4Me Study, using accelerometer data collected remotely via the Internet.Methods
Of the 1607 participants recruited, 1287 (539 men and 748 women) provided at least 3 weekdays and 2 weekend days of valid accelerometer data (TracmorD) at baseline and were included in the present analyses.Results
Men were significantly more active than women (physical activity level = 1.74 vs. 1.70, p < 0.001). Time spent in light PA and moderate PA differed significantly between countries but only for women. Adherence to the World Health Organization recommendation to accumulate at least 150 min of moderate-equivalent PA weekly was similar between countries for men (range: 54–65%) but differed significantly between countries for women (range: 26–49%). Prevalence estimates decreased substantially for men and women in all seven countries when PA guidelines were defined as achieving 30 min of moderate and vigorous PA per day.Conclusions
We were able to obtain valid accelerometer data in real time via the Internet from 80% of participants. Although our estimates are higher compared with data from Sweden, Norway, Portugal and the US, there is room for improvement in PA for all countries involved in the Food4Me Study. 相似文献10.
Weitz D Harder D Casagrande F Fotiadis D Obrdlik P Kelety B Daniel H 《The Journal of biological chemistry》2007,282(5):2832-2839
The ydgR gene of Escherichia coli encodes a protein of the proton-dependent oligopeptide transporter (POT) family. We cloned YdgR and overexpressed the His-tagged fusion protein in E. coli BL21 cells. Bacterial growth inhibition in the presence of the toxic phosphonopeptide alafosfalin established YgdR functionality. Transport was abolished in the presence of the proton ionophore carbonyl cyanide p-chlorophenylhydrazone, suggesting a proton-coupled transport mechanism. YdgR transports selectively only di- and tripeptides and structurally related peptidomimetics (such as aminocephalosporins) with a substrate recognition pattern almost identical to the mammalian peptide transporter PEPT1. The YdgR protein was purified to homogeneity from E. coli membranes. Blue native-polyacrylamide gel electrophoresis and transmission electron microscopy of detergent-solubilized YdgR suggest that it exists in monomeric form. Transmission electron microscopy revealed a crown-like structure with a diameter of approximately 8 nm and a central density. These are the first structural data obtained from a proton-dependent peptide transporter, and the YgdR protein seems an excellent model for studies on substrate and inhibitor interactions as well as on the molecular architecture of cell membrane peptide transporters. 相似文献