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1.
Giorgio Trinchieri Marek Kubin Graziella Bellone Marco A. Cassatella 《Journal of cellular biochemistry》1993,53(4):301-308
Cytokines represent one of the most important elements in the communication among different cell types. They play an increasingly better understood role in the communication among hematopoietic cells and in particular in the reciprocal regulation of effector cell types of innate or natural resistance (phagocytic cells and Natural Killer (NK) cells) and those of adaptive immunity (T and B lymphocytes). Lymphocytes produce several cytokines with either stimulatory (e.g., colony stimulatory factor) or suppressive (e.g., tumor necrosis factors and interferons) effects on proliferation of early hematopoietic cells. Many of these cytokines, alone or acting in synergistic combinations, also have a differentiation-inducing ability on immature myeloid cells and act as powerful potentiators of the cellular functions of terminally differentiated phagocytic cells. The communication between lymphocytes and phagocytic cells is not unidirectional, as phagocytic cells produce factors that regulate lymphocyte activation. In addition to their role as antigen presenting cells expressing costimulatory accessory molecules and secreting cytokines (e.g., IL-1, IL-6, TNF), phagocytic cells have been recently shown to produce Natural Killer cell Stimulatory Factor (NKSF/IL-12). IL-12 is a heterodimeric cytokine with important modulatory functions on cytotoxicity of NK and T cells, lymphocyte proliferation, lymphokine production, and development of T helper cell subsets. These communications between phagocytic cells and lymphocytes are further regulated by negative and positive feedback mechanisms that contribute to maintain the homeostasis of the system in physiologic conditions and to govern the changes in this equilibrium needed for the response to infectious or other foreign agents. 相似文献
2.
Extracellular recordings were made from inspiratory beta- (I beta) neurons in the nucleus of the tractus solitarius in decerebrate cats. A reversible direct current block of myelinated fibers in the ipsilateral vagus nerve was used to evaluate the input from pulmonary stretch receptor afferents (PSR) of the contralateral vagus to individual I beta-neurons. This block served to remove all ipsilateral (which includes all monosynaptic) inputs from PSR to I beta-cells. The effect of withholding inflation on the firing rate and the time of onset of firing of I beta-neurons was determined before, during and after application of the direct current block. There was considerable variation in the strengths of the inputs from the ipsilateral and contralateral nerves; some cells received PSR inputs from only the ipsilateral vagus, but the majority were excited with varying magnitude from both vagi. Several neurons had powerful excitatory inputs from PSR of the contralateral vagus, with the ipsilateral (monosynaptic) contribution being of minor importance. 相似文献
3.
Biologia Plantarum - The author has studied the relation of the catalase activity in thermal blue-green algae to temperature. Experimental data were taken from the first phase of the reaction, so... 相似文献
4.
Sandra Youngman Mansoor Sarfarazi Maja Bucan Marcy MacDonald Barbara Smith Michael Zimmer Conrad Gilliam Anna-Maria Frischauf John J. Wasmuth James F. Gusella Hans Lehrach Peter S. Harper Duncan J. Shaw 《Genomics》1989,5(4)
Genetic linkage studies have mapped Huntington's disease (HD) to the distal portion of the short arm of chromosome 4 (4p16.3), 4 cM distal to D4S10 (G8). To date, no definite flanking marker has been identified. A new DNA marker, D4S90 (D5), which maps to the distal region of 4p16.3, is described. The marker was used in a genetic linkage study in the CEPH reference families with seven other markers at 4p16. The study, together with knowledge of the physical map of the region, places D4S90 as the most distal marker, 6 cM from D4S10. A provisional linkage study with HD gave a maximum lod score of 2.14 at a θ of 0.00 and no evidence of linkage disequilibrium. As D4S90 appears to be located terminally, it should play an important role in the accurate mapping and cloning of the HD gene. 相似文献
5.
Anna-Maria M. Schmid 《Plant Systematics and Evolution》1989,164(1-4):239-252
The ultrastructure of the diatomSynedra cf.ulna was examined paying special attention to the Plattenband (platelet band). This structure was first described byGeitler in 1948 on the basis of LM observations and denotes a linear array of dictyosomes along the apical axis of the cell. The present investigation confirmsGeitler's observations in all essential details and demonstrates that the dictyosomes are arranged along polarized nuclear extensions running towards the cell poles. Laterally the extensions are accompanied by a number of microtubules. In large cells the total length of the nucleus thus may reach 400 µm and more. Since only the central part of the nucleus is DNA-positive with DAPI and acridine orange, the nuclear nature of the backbone of the Plattenband cannot be recognized by LM techniques. TEM investigation of serial apical and transapical sections, however, prove unambiguously the identity with extended parts of the nucleus.Dedicated to Prof. DrLothar Geitler on the occasion of his 90th birthday. 相似文献
6.
Anna-Maria M. Schmid 《Protoplasma》1994,181(1-4):43-60
Summary Aspects of morphogenesis and morphology of diatom cell walls are reviewed to highlight functional correlations between wall structures and three-dimensional cytoplasmic activities during the cell cycle. Morphogenesis of the siliceous valve within the silica deposition vesicle is discussed in the light of the dependency on a precisely orchestrated moulding machinery, involving the cytoskeleton, mitochondria, endoplasmic reticulum, spacer vesicles produced by the Golgi apparatus, and the plasmalemma, in combination with adhesion of the cells to parts of the parental wall and localized plasmolyses. Sensitivity of morphogenetic events to fluctuations of external factors has implications for taxonomy.Abbreviations CF
cleavage furrows
- cPL
cleavage plasmalemma
- GB
girdle bands
- LP
labiate process
- LPA
labiate process apparatus
- MC
microtubule center
- mLP
macro labiate process
- MT
microtubule
- MTOC
microtubules organizing center
- PL
plasmalemma
- SDV
silica deposition vesicle
- SL SDV
membrane
- SpV
spacer vesicles
Dedicated to Professor Peter Sitte on the occasion of his 65th birthday 相似文献
7.
8.
R Kalich G Bennert T Fiedler M Kubin M MezenskyLTurzova H Ulber 《Journal of hygiene, epidemiology, microbiology, and immunology》1979,23(3):307-317
In cooperation of 6 laboratories in Czechoslovakia and in the GDR, the efficiency of auramine-rhodamine B (AR) and acridine orange (AO) (short-time method) for staining of acid-fast bacilli was compared. Whereas a former comparison of AR and AO (original method) pointed out the superiority of AR, the investigation of both methods used as short-time procedures showed significantly more acid-fast rods after using AO. The number of "false positive" results was somewhat higher on AR staining. However the results depend not only on the method used but also on the procedure of staining and the optical equipment, and they are essentially influenced by the experience and proficiency of the microscopist. Taking into account the results of both studies both auramine-rhodamine B and acridine orange can be proposed for the staining of slides for microscopical detection of acid-fast rods. In case of AO, the short-time method is superior to the original long-time procedure. 相似文献
9.
10.
Jurgen Vercauteren Gertjan Beheydt Mattia Prosperi Pieter Libin Stijn Imbrechts Ricardo Camacho Bonaventura Clotet Andrea De Luca Zehava Grossman Rolf Kaiser Anders S?nnerborg Carlo Torti Eric Van Wijngaerden Jean-Claude Schmit Maurizio Zazzi Anna-Maria Geretti Anne-Mieke Vandamme Kristel Van Laethem 《PloS one》2013,8(4)