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181.
M. A. KH. MOUNLA 《Physiologia plantarum》1978,44(3):268-272
In husks, the activity of gibberellin-like substances extracted with aqueous methanol (M-“free” GAs) showed a maximum on the 9th day after pollination. In developing embryos, M-“free” GAs showed no biological activity, whereas biological active component(s) were obtained when the embryos were extracted with Tris buffer. The “free” GAs found in the buffer homogenates (B-“free” GAs) of developing embryos showed a maximum of activity on the 33rd day after pollination. Bound GAs recovered from the precipitated protein of the buffer homogenate (“Protein-bound” GAs) were found in embryo and endosperm. Developing endosperm generally contains the major amount of the extractable gibberellin-like substances. In this tissue, the amount of all examined fractions (M-“free” GAs, B-“free” GAs and “protein-bound” GAs) increased after pollination to reach a maximum on the 21st day, before decreasing to a minimum at grain maturity. Moreover, the curves for dry weight increase and gibberellin like substances follow a remarkably similar course, with the latter reaching its maximim slightly earlier than the former one. This result indicates that gibberellines may participate in the regulation of the accumulation process in the endosperm of barley grain. 相似文献
182.
IL-27 mediates complete regression of orthotopic primary and metastatic murine neuroblastoma tumors: role for CD8+ T cells 总被引:7,自引:0,他引:7
Salcedo R Stauffer JK Lincoln E Back TC Hixon JA Hahn C Shafer-Weaver K Malyguine A Kastelein R Wigginton JM 《Journal of immunology (Baltimore, Md. : 1950)》2004,173(12):7170-7182
We have shown previously that IFN-gamma-inducing cytokines such as IL-12 can mediate potent antitumor effects against murine solid tumors. IL-27 is a newly described IL-12-related cytokine that potentiates various aspects of T and/or NK cell function. We hypothesized that IL-27 might also mediate potent antitumor activity in vivo. TBJ neuroblastoma cells engineered to overexpress IL-27 demonstrated markedly delayed growth compared with control mice, and complete durable tumor regression was observed in >90% of mice bearing either s.c. or orthotopic intra-adrenal tumors, and 40% of mice bearing induced metastatic disease. The majority of mice cured of their original TBJ-IL-27 tumors were resistant to tumor rechallenge. Furthermore, TBJ-IL-27 tumors were heavily infiltrated by CD8(+) T cells, and draining lymph node-derived lymphocytes from mice bearing s.c. TBJ-IL-27 tumors are primed to proliferate more readily when cultured ex vivo with anti-CD3/anti-CD28 compared with lymphocytes from mice bearing control tumors, and to secrete higher levels of IFN-gamma. In addition, marked enhancement of local IFN-gamma gene expression and potent up-regulation of cell surface MHC class I expression are noted within TBJ-IL-27 tumors compared with control tumors. Functionally, these alterations occur in conjunction with the generation of tumor-specific CTL reactivity in mice bearing TBJ-IL-27 tumors, and the induction of tumor regression via mechanisms that are critically dependent on CD8(+), but not CD4(+) T cells or NK cells. Collectively, these studies suggest that IL-27 could be used therapeutically to potentiate the host antitumor immune response in patients with malignancy. 相似文献
183.
Construction of bacterial artificial chromosome library from electrochemical microorganisms 总被引:5,自引:0,他引:5
Back JH Kim MS Cho H Chang IS Lee J Kim KS Kim BH Park YI Han YS 《FEMS microbiology letters》2004,238(1):65-70
A microbial fuel cell is a device that directly converts metabolic energy into electricity, using electrochemical technology. The analysis of large genome fragments recovered directly from microbial communities represents one promising approach to characterizing uncultivated electrochemical microorganisms. To further assess the utility of this approach, we constructed large-insert (140 kb) bacterial artificial chromosome (BAC) libraries from the genomic DNA of a microbial fuel cell, which had been operated for three weeks using acetate media. We screened the expression of several ferric reductase activities in the Escherichia coli host, in order to determine the extent of heterologous expression of metal-ion-reducing enzymes in the library. Phylogenetic analysis of 16S rRNA gene sequences recovered from the BAC libraries indicates that they contain DNA from a wide diversity of microbial organisms. The constructed bacterial library proved a powerful tool for exploring metal-ion reductase activities, providing information on the electron transport pathway of electrochemical microbial (ECM) organisms. 相似文献
184.
Roy AS Banerjee RK Back LH Back MR Khoury S Millard RW 《American journal of physiology. Heart and circulatory physiology》2005,289(1):H392-H397
Hemodynamic analysis was conducted to determine uncertainty in clinical measurements of coronary flow reserve (CFR) and fractional flow reserve (FFR) over pathophysiological conditions in a patient group with coronary artery disease during angioplasty. The vasodilation-distal perfusion pressure (CFR-p(rh)) curve was obtained for 0.35- and 0.46-mm guide wires. Our hypothesis is that a guide wire spanning the lesions elevates the pressure gradient and reduces the flow during hyperemic measurements. Maximal CFR-p(rh) was uniquely determined by the intersection of measured CFR and calculated p(rh) of native and residual epicardial lesions in patients without microvascular disease, during angioplasty. Extrapolation of the linear curve gave a zero-coronary flow mean pressure (p(zf)) of approximately 20 mmHg and a corresponding p(rh) of 55 mmHg in the native lesions, which coincided with the level that causes ischemia in human hearts. On this linear curve, values of CFR and FFRmyo (pathophysiological condition) and CFRg and FFRmyog (in the presence of the guide wire) were obtained in native and residual lesions. A strong linear correlation was found between CFR and CFRg [CFR = CFRg x 0.689 + 1.271 (R2= 0.99) for 0.46 mm and CFR = CFRg x 0.757 + 1.004 (R2= 0.99) for 0.35 mm] and between FFRmyo and FFRmyog [FFRmyo = FFRmyog x 0.737 + 0.263 (R2= 0.99) for 0.46 mm and FFRmyo = FFRmyog x 0.790 + 0.210 (R2= 0.99) for 0.35 mm]. This study establishes a strong correlation between CFR and CFRg and between FFRmyo and FFRmyog, which could be used to obtain the true state of occlusion in the coronary artery during angioplasty. 相似文献
185.
Summary The association pattern of the acrocentric chromosomes shows no significant difference between a population of mothers of mongoloid children and male and female controls of the same age-group. It could only be demonstrated that the associations of the mothers were interconnected by thread-like structures in a higher percentage. However, no significance could be deduced from for this phenomenon (P 0.1).
Mit Unterstützung durch die Fritz-Thyssen-Stiftung und die Deutsche Forschungs-gemeinschaft
Mit technischer Assistenz von Regine Heiland 相似文献
Mit Unterstützung durch die Fritz-Thyssen-Stiftung und die Deutsche Forschungs-gemeinschaft
Mit technischer Assistenz von Regine Heiland 相似文献
186.
Intra-specific heterogeneity of the rDNA internal transcribed spacer in the Simulium damnosum (Diptera: Simuliidae) complex 总被引:3,自引:0,他引:3
The internal transcribed spacer (ITS) of the rRNA gene cluster has been
used as a model for the study of the action of concerted evolution and
molecular drive on repeated sequence families. In contrast to this general
finding, preliminary DNA sequence analysis of cloned representatives of the
ITS from the West African black fly species complex Simulium damnosum s.1.
demonstrated extensive intra-individual and intra-specific polymorphisms.
Variability in the ITS was primarily confined to the ITS1 domain. The
degree and type of intra-individual and intra-specific variability within
the ITS was further characterized using gel electrophoresis, DNA
hybridization, and heteroduplex analysis of the PCR products generated from
the ITS1 domain. ITS1 copies from individual S. damnosum s.1. differed in
length and sequence composition. These results, when taken together,
demonstrate that a large degree of intra-individual and intra-specific
heterogeneity exists in the ITS of S. damnosum s.1. The intra-individual
heterogeneity was greater in the savanna-dwelling than forest-dwelling
sibling species of S. damnosum s.1. This heterogeneity may be due in part
to inter-breeding among sympatric sibling species, coupled with disturbance
of S. damnosum s.1. populations resulting from intensive vector control
efforts.
相似文献
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190.
Jong Myong Park Young-Hyun You Chang-Gi Back Hyeong-Hwan Kim Sa-Youl Ghim Jong-Han Park 《Symbiosis (Philadelphia, Pa.)》2018,74(2):145-158
Larvae of Bradysia agrestis, a phytopathogen-transmitting insect vector in East Asia, were sampled from geographically (ecologically) segregated regions to identify their intestinal fungal flora. A total of 24 fungal strains were isolated from the insect vectors and selected based on morphological differences. In addition, 38 fungal strains were isolated from the ulcerated parts of invaded host plants by the same method, revealing the impact of vector fungal flora on their host plants. For molecular identification of the fungi, internal transcribed spacer (ITS) regions were amplified and sequenced. Their sequences were compared with sequences of other fungal strains obtained from NCBI GenBank, and their phylogeny was determined. The dominant fungal genera in the insect vector were Penicillium (25%), Aspergillus (21%), and Cladosporium (13%). In plant scar lesions, most fungal isolates belonged to the genera Fusarium (31.6%), Phoma (7.8%), Didymella (7.8%), and Epicoccum (7.8%). Fungal genera in vectors or host plant lesions differed by study site. Furthermore, diversity indices by study site showed clear differences based on Margalef’s richness (2.06, 2.40, 3.04), and Menhinick’s (1.89, 2.12, 2.53), and Simpson’s indices (0.14, 0.07, 0.07). In addition, common fungal strains in insect vectors were found to be closely related to members of the genera Cladosporium, Penicillium, or Aspergillus. Among these strains, those showing the highest homology with Aspergillus terreus, which regarded as beneficial fungal genera could be considered ideal paratransgenesis candidates. Some other fungal strains from vectors or ulcerated plant parts from each study site after B. agrestis invasion may be harmful in terms of plant disease or agrifood safety. This study provides information on the fungal microbiota of B. agrestis, an emerging problem in East Asia, and proposes paratransgenesis candidates to control this insect vector. Furthermore, potential transferable pathogens or commensal fungi were revealed by comparing the fungal biota between the insect gut and the ulcerated parts of the invaded host plants. 相似文献