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101.
1H-Indole-4,7-diones were synthesized and tested for in vitro antifungal activity against fungi. The synthesized 1H-indole-4,7-diones generally showed good antifungal activity against Candida krusei, Cryptococcus neoformans, and Aspergillus niger. The results suggest that 1H-indole-4,7-diones would be potent antifungal agents.  相似文献   
102.
The role of ammonia-oxidizing archaea (AOA) in nitrogen cycling in marine sediments remains poorly characterized. In this study, we enriched and characterized AOA from marine sediments. Group I.1a crenarchaea closely related to those identified in marine sediments and “Candidatus Nitrosopumilus maritimus” (99.1 and 94.9% 16S rRNA and amoA gene sequence identities to the latter, respectively) were substantially enriched by coculture with sulfur-oxidizing bacteria (SOB). The selective enrichment of AOA over ammonia-oxidizing bacteria (AOB) is likely due to the reduced oxygen levels caused by the rapid initial growth of SOB. After biweekly transfers for ca. 20 months, archaeal cells became the dominant prokaryotes (>80%), based on quantitative PCR and fluorescence in situ hybridization analysis. The increase of archaeal 16S rRNA gene copy numbers was coincident with the amount of ammonia oxidized, and expression of the archaeal amoA gene was observed during ammonia oxidation. Bacterial amoA genes were not detected in the enrichment culture. The affinities of these AOA to oxygen and ammonia were substantially higher than those of AOB. [13C]bicarbonate incorporation and the presence and activation of genes of the 3-hydroxypropionate/4-hydroxybutyrate cycle indicated autotrophy during ammonia oxidation. In the enrichment culture, ammonium was oxidized to nitrite by the AOA and subsequently to nitrate by Nitrospina-like bacteria. Our experiments suggest that AOA may be important nitrifiers in low-oxygen environments, such as oxygen-minimum zones and marine sediments.Archaea have long been known as extremophiles, since most cultivated archaeal strains were cultivated from extreme environments, such as acidic, hot, and high-salt environments. The view of archaea as extremophiles (i.e., acidophiles, thermophiles, and halophiles) has radically changed by the application of molecular technologies, including PCR in environmental microbiology. Using Archaea-specific PCR primers, novel archaeal 16S rRNA gene sequences were discovered in seawater (23, 27). Following these discoveries, an ever-increasing and unexpectedly high variety of archaeal 16S rRNA gene sequences has been reported from diverse “nonextreme” environments (67). This indicates that archaea are, like bacteria, ubiquitous in the biosphere rather than exclusively inhabiting specific extreme niches. Archaea are abundant in water columns of some oceanic provinces (33, 36) and deep-subsea floor sediments (11, 12, 48). Despite the increasing number of reports of the diversity and abundance of these nonextreme archaea by molecular ecological studies, their physiology and ecological roles have remained enigmatic.Oxidation of ammonia, a trait long thought to be exclusive to the domain Bacteria (13), was recently suggested to be a trait of archaea of the crenarchaeal groups I.1a and I.1b, based on a metagenome analysis (79) and supported by the discovery of archaeal amoA-like genes in environmental shotgun sequencing studies of Sargasso Sea water (80) and genomic analysis of “Candidatus Cenarchaeum symbiosum,” a symbiont of a marine sponge (30). Molecular ecological studies indicated that these ammonia-oxidizing archaea (AOA) are often predominant over ammonia-oxidizing bacteria (AOB) in ocean waters (9, 53, 87), soils (17, 47), and marine sediments (61). Critical evidence for autotrophic archaeal ammonia oxidation was obtained by the characterization of the first cultivated mesophilic crenarchaeon (group I.1a), “Candidatus Nitrosopumilus maritimus SCM1,” from an aquarium (38), and a related archaeon from North Sea water (87) and subsequently by enrichment of thermophilic AOA (22, 31). Whole-genome-based phylogenetic studies recently indicated that the nonthermophilic crenarchaea, including the AOA, likely form a phylum separate from the Crenarchaeota and Euryarchaeota phyla (15, 16, 72). This proposed new phylum was called Thaumarchaeota (15).Microorganisms in marine sediments contribute significantly to global biogeochemical cycles because of their abundance (85). Nitrification is essential to the nitrogen cycle in marine sediments and may be metabolically coupled with denitrification and anaerobic ammonium oxidation, resulting in the removal of nitrogen as molecular nitrogen and the generation of greenhouse gases, such as nitrous oxide (19, 75). Compared with studies on archaeal nitrification in the marine water column, only limited information on archaeal nitrification in marine sediments is available so far. Archaeal amoA genes have been retrieved from marine and coastal sediments (8, 26, 61), and the potentially important role of AOA in nitrification has been suggested based on the abundance of archaeal amoA genes relative to that of bacterial amoA genes in surface marine sediments from Donghae (South Korea) (61). Cultivation of AOA, although difficult (38), remains essential to estimating the metabolic potential of archaea in environments such as soils (47) and marine sediments (61). Here, we report the successful enrichment of AOA of crenarchaeal group I.1a from marine sediments by employing a coculture with sulfur-oxidizing bacteria (SOB) which was maintained for ca. 20 months with biweekly transfers. In this way, we were able to characterize AOA from marine sediments, providing a clue for the role of AOA in the nitrogen cycle of marine sediments.  相似文献   
103.
A series of 1H-pyrrolo[2,3-c]pyridines as acid pump antagonists (APAs) was synthesized and the inhibitory activities against H+/K+ ATPase isolated from hog gastric mucosa were determined. After elaborating on substituents at N1, C5, and C7 position of 1H-pyrrolo[2,3-c]pyridine scaffold, we have observed that compounds 14f and 14g are potent APAs with H+/K+ ATPase IC50 = 28 and 29 nM, respectively.  相似文献   
104.
The shortnose sturgeon Acipenser brevirostrum was revealed to have a larger number of chromosomes than previously reported for other sturgeon species. Its chromosome number ranged from 362 to 372 (of ten specimens examined), showing intraindividual variation. The karyotype of metaphase with the highest chromosome number (372) consisted of 89 pairs of macrochromosomes and 97 pairs of microchromosomes (fundamental number; NF=550). Although the microchromosomes were relatively shorter than the macrochromosomes, most of them had discernible arms and centromeres. Silver-stained nucleolar organizer regions (Ag-NORs) were localized on the telomeric regions of 5 pairs of chromosomes (Ag-NORs=10): 4 were made up of small meta/submetacentrics and 1 of acrocentrics. Polyploidy of A. brevirostrum should be hexaploid based on the karyotype, numerous chromosomes, Ag-NORs, and previously reported large genome size (ca. 13pg DNA/cell).Supplementary material to this paper is available in electronic format at http://dx.doi.org/10.1007/s10228-004-0257-z  相似文献   
105.
Adipogenesis is a complex process that is accompanied by a number of molecular events. In this study, a proteomic approach was adopted to identify secretory factors associated with adipogenesis. A label‐free shotgun proteomic strategy was implemented to analyze proteins secreted by human adipose stromal vascular fraction cells and differentiated adipocytes. A total of 474 proteins were finally identified and classified according to quantitative changes and statistical significances. Briefly, 177 proteins were significantly upregulated during adipogenesis (Class I), whereas 60 proteins were significantly downregulated (Class II). Changes in the expressions of several proteins were confirmed by quantitative RT‐PCR and immunoblotting. One obvious finding based on proteomic data was that the amounts of several extracellular modulators of Wnt and transforming growth factor‐β (TGF‐β) signaling changed during adipogenesis. The expressions of secreted frizzled‐related proteins, dickkopf‐related proteins, and latent TGF‐β‐binding proteins were found to be altered during adipogenesis, which suggests that they participate in the fine regulation of Wnt and TGF‐β signaling. This study provides useful tools and important clues regarding the roles of secretory factors during adipogenic differentiation, and provides information related to obesity and obesity‐related metabolic diseases.  相似文献   
106.
Eucommia ulmoides Oliver was tested to control the differentiation of cultured human mesenchymal stem cell into adipocyte. The extent of the inhibitory effect on the conversion of adipose was measured using Oil red O staining, which stains accumulated lipid droplets in the cytoplasm of adipocyte. The adipocyte differentiation was inhibited by an extract from E. ulmoides Oliver in the concentration range 0.01–50.0 g/l. After 2D PAGE, protein spots of E. ulmoides Oliver extract treated stem cells were analyzed. Several protein spots were strongly up-regulated in E. ulmoides Oliver extract treated cells. Among them, tropomyosin was identified by MALDI-TOF. These results suggest that E. ulmoides Oliver has an inhibitory activity toward the adipose conversion, which is a major cause of obesity.  相似文献   
107.
Glycosylated, membrane-associated E1 (58-kDa) and E2 (47- to 49-kDa) rubella virus proteins and unglycosylated nucleoprotein C (33 kDa), from separately expressed vaccinia virus recombinants, were injected into golden Syrian hamsters. Rubella virus E1 and E2 glycoproteins consistently induced an organ-specific autoimmune disease, autoimmune lymphocytic hypophysitis, which was evidenced by the induction of autoantibodies against pituitary cells and by lymphocytic infiltration of the pituitary. Neonatal thymectomy prevented the disease. In contrast, rubella virus nucleoprotein C did not induce either autoantibodies against pituitary cells or lymphocytic infiltration of the pituitary. This finding raises the possibility that virus-specific protein itself can induce an organ-specific autoimmune disease in certain circumstances.  相似文献   
108.
109.
Follicles are important in oocyte maturation. Successful estrous cycle requires remodeling of follicular cells, and proper execution of programmed cell death is crucial for normal follicular development. The objectives of the present study were to understand programmed cell death during follicle development, to analyze the differential follicle development patterns, and to assess the patterns of apoptosis and autophagy expression during follicle development in normal and miniature pigs. Through the analysis of differential patterns of programmed cell death during follicular development in porcine, MAP1LC3A, B and other autophagy-associated genes (ATG5, mTOR, Beclin-1) were found to increase in normal pigs, while it decreased in miniature pigs. However, for the apoptosis-associated genes, progression of genes during follicular development increased in miniature pigs, while it decreased in normal pigs. Thus, results show that normal and miniature pigs showed distinct patterns of follicular remodeling manifesting that programmed cell death largely depends on the types of pathway during follicular development (Type II or autophagy for normal pigs and Type I or apoptosis for miniature pigs).  相似文献   
110.
Applied Microbiology and Biotechnology - Resistant starch (RS) in the diet reaches the large intestine without degradation, where it is decomposed by the commensal microbiota. The fermentation of...  相似文献   
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