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151.
A critical taxonomic revision of the genus Teucrium (Lamiaceae) in Egypt is presented. It reveals the presence of five species, including two subspecies and four varieties. Two new nomenclatural combinations are proposed: Teucrium jordanicum and T. jordanicum var. sinaicum. The latter in addition to T. polium subsp. capitatum are added for the first time to the flora of the country. A key, annotated enumeration of species and notes on the distribution of the species are also provided. 相似文献
152.
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154.
B220+ double-negative T cells suppress polyclonal T cell activation by a Fas-independent mechanism that involves inhibition of IL-2 production 总被引:4,自引:0,他引:4
Hamad AR Mohamood AS Trujillo CJ Huang CT Yuan E Schneck JP 《Journal of immunology (Baltimore, Md. : 1950)》2003,171(5):2421-2426
Fas-mediated apoptosis is a key mechanism for elimination of autoreactive T cells, yet loss of function mutations in the Fas signaling pathway does not result in overt T cell-mediated autoimmunity. Furthermore, mice and humans with homozygous Fas(lpr) or Fas ligand(gld) mutations develop significant numbers of B220+ CD4- CD8- double-negative (DN) alphabeta T cells (hereafter referred to as B220+ DN T cells) of poorly understood function. In this study, we show that B220+ DN T cells, whether generated in vitro or isolated from mutant mice, can suppress the ability of activated T cells to proliferate or produce IL-2, IL-10, and IFN-gamma. B220+ DN T cells that were isolated from either lpr or gld mice were able to suppress proliferation of autologous and syngeneic CD4 T cells, showing that suppression is Fas independent. Furthermore, restoration of Fas/Fas ligand interaction did not enhance suppression. The mechanism of suppression involves inhibition of IL-2 production and its high affinity IL-2R alpha-chain (CD25). Suppression also requires cell/cell contact and TCR activation of B220+ DN T cells, but not soluble cytokines. These findings suggest that B220+ DN T cells may be involved in controlling autoreactive T cells in the absence of Fas-mediated peripheral tolerance. 相似文献
155.
Labiba Temmim Fred Sinowatz Wiam I Hussein Osama Al-Sanea Hady El-Khodary 《Diagnostic pathology》2008,3(1):1-6
Aims
To analyse the histo-morphology of cases of medullomyoblastoma and identifying its divergent differentiation.Methods
A retrospective review of all cases reported as medulloblastoma between the period of Jan 2000 to Dec 2006 was carried out on Hematoxylin and eosin (H & E) stained slides. The cases were screened on light microscopy for primitive neuroectodermal component of a medulloblastoma accompanied by areas of "myoid" differentiation, identified on the basis of presence of strap cells (indicating a clear skeletal muscle differentiation) and/or large anaplastic cells with vescicular nuclei and moderate to abundant amount of eosinophilic cytoplasm. All these cases were subjected to a panel of immunohistochemical stains, including Desmin, GFAP, NFP, HMB45, SMA, S100, CK and EMA. Ultrastructral analysis was done on tissue obtained from paraffin blocks in 2 cases.Results
Male predominance (M:F = 5:1) was noted with an incidence of five percent of all cases of medulloblastoma (6 out of 120 cases) over a period of 6 years. Primitive neuroectodermal areas were accompanied with areas of "myoid" differentiation, 5 cases showing strap cells. Two cases with epithelial and cartilaginous differentiation were seen. Three cases showed focal melanocytic differentiation, identified only on HMB45 immunostaining. Four cases showed glial differentiation. Neuronal differentiation again was very focally seen in two cases, of which one was identified only by NFP immunostain. Seventh case is included in the study, however it is not considered to calculate incidence as it occurred beyond the period of 6 years of records search.Conclusion
Medullomyoblastoma is a rare childhood tumor of cerebellum. Majority of cases reveal divergent differentiation, which are identified with the help of panel of immunostains indicating multi-potential nature of primitive neuroectodermal cells. 相似文献156.
Badria B El Sayed Colin A Malcolm Ahmed Babiker Elfatih M Malik Mohammed AH El Tayeb Nageeb S Saeed Abdel Hameed D Nugud Bart GJ Knols 《Malaria journal》2009,8(Z2):S3
The global malaria situation, especially in Africa, and the problems frequently encountered in chemical control of vectors such as insecticide resistance, emphasize the urgency of research, development and implementation of new vector control technologies that are applicable at regional and local levels. The successful application of the sterile insect technique (SIT) for the control of the New World screwworm Cochliomyia hominivorax and several species of fruit flies has given impetus to the use of this method for suppression or elimination of malaria vectors in some areas of Africa including Northern State of Sudan. The research and development phase of the Northern State feasibility study has been started. Sudanese stakeholders are working side-by-side with the International Atomic Energy Agency in the activities of this important phase. Several ethical, legal and social issues associated with this approach arose during this phase of the project. They need to be seriously considered and handled with care. In this paper, these issues are described, and the current and proposed activities to overcome potential hurdles to ensure success of the project are listed. 相似文献
157.
158.
This study aimed to isolate quercetin (for the first time) from Anabaena aequalis Borge, which inhabits soil surface of Wadi El‐Alaqui Protectorate located in Aswan city, Egypt. The isolated compound showed significant antibacterial activity against the gram‐positive bacteria Sarcina maxima and Micrococcus kristinae, the gram‐negative bacterium Klebsiella pneumoniae, as well as against the filamentous fungus Aspergillus flavus. The isolated compound was identified as quercetin using the structure elucidation based on UV, electrospray ionization mass spectrometry (ESIMS), 1H and 13C NMR, proton–proton correlation spectroscopy (1H‐1H COSY), distortionless enhancement by polarization transfer (DEPT), heteronuclear single quantum coherence (HSQC), and heteronuclear multiple bond correlations spectrum (HMBC). Medium lethal dose (LD50) of the isolated compound and its side effects against hyperlipidemia induced by ethanol intake in albino rats were carried out. No deaths were reported in rats within 72 h, which suggests that the isolated compound plays a beneficial role as an antihyperlipidemic agent in the treatment of alcohol‐induced hepatic tissue damage, which can be described as one of the therapeutic values. 相似文献
159.
Synthesis and characterization of ion‐imprinted resin for selective removal of UO2(II) ions from aqueous medium 下载免费PDF全文
M. Monier Raedah A. S. Alatawi D. A. Abdel‐Latif 《Journal of molecular recognition : JMR》2015,28(5):306-315
In this work, uranyl ion‐imprinted resin based on 2‐(((4‐hydroxyphenyl)amino)methyl)phenol was synthesized by condensation polymerization of its uranyl complex in presence of resorcinol and formaldehyde cross‐linkers. Numerous instrumental techniques including elemental analysis, Fourier transform infrared spectroscopy, ultraviolet, 1H along with 13C nuclear magnetic resonance spectroscopy have been employed for complete characterization of the synthesized ligand and its uranyl complex. Additionally, the obtained ion‐imprinted and non‐imprinted resins were investigated using scanning electron microscope and Fourier transform infrared spectroscopy. The effects of various essential parameters such as pH, temperature and contact time on removal of uranyl ions have been examined, and the results indicated that the obtained resin exhibited the optimum activity at pH 5. Furthermore, the adsorption process was spontaneous at all studied temperatures and followed the second‐order kinetics model. Also, Langmuir adsorption isotherm exhibited the best fit with the experimental results with maximum adsorption capacity 139.3 mg/g. Moreover, the selectivity studies revealed that the ion‐imprinted resin exhibited an obvious affinity toward the uranyl ions in presence of other metal ions compared with the non‐imprinted resin. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
160.
Abdel‐Rahman S. Sultan Yasuhiro Oish Hitoshi Ueda 《Development, growth & differentiation》2014,56(3):245-253
The nuclear receptor βFTZ‐F1 is expressed in most cells in a temporally specific manner, and its expression is induced immediately after decline in ecdysteroid levels. This factor plays important roles during embryogenesis, larval ecdysis, and early metamorphic stages. However, little is known about the expression pattern, regulation and function of this receptor during the pupal stage. We analyzed the expression pattern and regulation of ftz‐f1 during the pupal period, as well as the phenotypes of RNAi knockdown or mutant animals, to elucidate its function during this stage. Western blotting revealed that βFTZ‐F1 is expressed at a high level during the late pupal stage, and this expression is dependent on decreasing ecdysteroid levels. By immunohistological analysis of the late pupal stage, FTZ‐F1 was detected in the nuclei of most cells, but cytoplasmic localization was observed only in the oogonia and follicle cells of the ovary. Both the ftz‐f1 genetic mutant and temporally specific ftz‐f1 knockdown using RNAi during the pupal stage showed defects in eclosion and in the eye, the antennal segment, the wing and the leg, including bristle color and sclerosis. These results suggest that βFTZ‐F1 is expressed in most cells at the late pupal stage, under the control of ecdysteroids and plays important roles during pupal development. 相似文献