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141.
142.
Arakawa H Karasawa K Munakata E Obinata R Maeda M Suzuki S Kamahori M Kambara H 《Analytical biochemistry》2008,379(1):86-90
DNA analysis is an important technology with respect to diagnosis of infectious disease and tailored medication. In this study, we developed a novel bioluminescent assay for pyrophosphate, and it was applied to single-nucleotide polymorphism (SNP) analysis using one-base extension reaction. The principle of this method is as follows. A specific primer within each aliquot possessing a short 3′ end of the base of interest was hybridized to the single-stranded DNA template. Subsequently, (exo-)Klenow DNA polymerase and one of either α-thio-dATP, dTTP, dGTP, or dCTP were added and incubated for 1 min. Pyrophosphate released by DNA polymerase is converted to ATP by pyruvate phosphate dikinase (PPDK), and the concentration of ATP is determined using the firefly luciferase reaction. This method, which does not require expensive equipment, can be used to rapidly monitor one point mutation in the gene. 相似文献
143.
Direct Profiling of Environmental Microbial Populations by Thermal Dissociation Analysis of Native rRNAs Hybridized to Oligonucleotide Microarrays 总被引:7,自引:5,他引:2
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Said El Fantroussi Hidetoshi Urakawa Anne E. Bernhard John J. Kelly Peter A. Noble H. Smidt G. M. Yershov David A. Stahl 《Applied microbiology》2003,69(4):2377-2382
Oligonucleotide microarrays were used to profile directly extracted rRNA from environmental microbial populations without PCR amplification. In our initial inspection of two distinct estuarine study sites, the hybridization patterns were reproducible and varied between estuarine sediments of differing salinities. The determination of a thermal dissociation curve (i.e., melting profile) for each probe-target duplex provided information on hybridization specificity, which is essential for confirming adequate discrimination between target and nontarget sequences. 相似文献
144.
Ammonia-oxidizing bacteria on root biofilms and their possible contribution to N use efficiency of different rice cultivars 总被引:12,自引:0,他引:12
Briones Aurelio M. Okabe Satoshi Umemiya Yoshiaki Ramsing Niels-Birger Reichardt Wolfgang Okuyama Hidetoshi 《Plant and Soil》2003,250(2):335-348
Ammonia-oxidizing bacteria (AOB) populations were studied on the root surface of different rice cultivars by PCR coupled with denaturing gradient gel electrophoresis (DGGE) and fluorescence in situ hybridization (FISH). PCR-DGGE of the ammonium monooxygenase gene (amoA) showed a generally greater diversity on root samples compared to rhizosphere and unplanted soil. Sequences affiliated with Nitrosomonas spp. tended to be associated with modern rice hybrid lines. Root-associated AOB observed by FISH were found within a discrete biofilm coating the root surface. Although the total abundance of AOB on root biofilms of different rice cultivars did not differ significantly, there were marked contrasts in their population structure, indicating selection of Nitrosomonas spp. on roots of a hybrid cultivar. Observations by FISH on the total bacterial community also suggested that different rice cultivars support different bacterial populations even under identical environmental conditions. The presence of active AOB in the root environment predicts that a significant proportion of the N taken up by certain rice cultivars is in the form of NO3
–-N produced by the AOB. Measurement of plant growth of hydroponically grown plants showed a stronger response of hybrid cultivars to the co-provision of NH4
+ and NO3
–. In soil-grown plants, N use efficiency in the hybrid was improved during ammonium fertilization compared to nitrate fertilization. Since ammonium-fertilized plants actually receive a mixture of NH4
+ and NO3
– with ratios depending on root-associated nitrification activity, these results support the advantage of co-provision of ammonium and nitrate for the hybrid cultivar. 相似文献
145.
Behavior of Psychrotrophic Lactic Acid Bacteria Isolated from Spoiling Cooked Meat Products
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Yoshikatsu Hamasaki Mitsuko Ayaki Hidetaka Fuchu Masaaki Sugiyama Hidetoshi Morita 《Applied microbiology》2003,69(6):3668-3671
Three kinds of lactic acid bacteria were isolated from spoiling cooked meat products stored below 10°C. They were identified as Leuconostoc mesenteroides subsp. mesenteroides, Lactococcus lactis subsp. lactis, and Leuconostoc citreum. All three strains grew well in MRS broth at 10°C. In particular, L. mesenteroides subsp. mesenteroides and L. citreum grew even at 4°C, and their doubling times were 23.6 and 51.5 h, respectively. On the other hand, although the bacteria were initially below the detection limit (<10 CFU/g) in model cooked meat products, the bacterial counts increased to 108 CFU/g at 10°C after 7 to 12 days. 相似文献
146.
Li Ming Tamate Hidetoshi B. Wei Fu -Wen Wang Xiao -Ming Masuda Ryuichi Sheng He -Lin Ohtaishi Noriyuki 《Acta theriologica》2003,48(2):207-219
The phylogenetic relationships of Cervidae and Moschidae were examined using partial sequence data of mitochondrial DNA (mtDNA)
cytochromeb. Ten new sequences were obtained for six species of Cervidae and Moschidae, and aligned with those previously reported for
other deer species. Our results demonstrated that the phylogenetic status of the taxa inferred from molecular data was congruent
with taxonomy based on morphological studies. Cervidae formed a monophyletic group that consists of four subfamilies: Cervinae,
Muntiacinae, Hydropotinae, and Odocoileinae. Moschidae occurred at the base of the Cervidae clade. On the basis of molecular
clocks for genetic distance, the divergence time of mtDNA haplotypes within the subfamily Cervinae, among subfamilies in Cervidae,
and between Moschidae and Cervidae was estimated to date 2–7 MYA, 6–10 MYA and 8–13 MYA, respectively. 相似文献
147.
Characteristics of surface mechanomyogram are dependent on development of fusion of motor units in humans. 总被引:2,自引:0,他引:2
Yasuhide Yoshitake Minoru Shinohara Hidetoshi Ue Toshio Moritani 《Journal of applied physiology》2002,93(5):1744-1752
The purpose of this study was to test whether surface mechanomyogram (MMG) recorded on the skin reflects the contractile properties of individual motor units in humans. Eight motor units in the medial gastrocnemius muscle were identified, and trains of stimulation at 5, 10, 15, and 20 Hz were delivered to each isolated motor unit. There was a significant positive correlation between the duration of MMG and twitch duration. MMG amplitude decreased with increasing stimulation frequency. Reductions in MMG amplitude were in parallel with the reductions in force fluctuations, and the rate of change in both was positively correlated across the motor units. Rate of change in MMG amplitude against force was negatively correlated to half relaxation time and twitch duration. Similar negative correlations were found between force fluctuations and contractile properties. These results provide evidence supporting a direct relation between MMG and contractile properties of individual motor units within the gastrocnemius muscle, indicating that surface MMG is dependent on the contractile properties of the activated motor units in humans. 相似文献
148.
Parallel Characterization of Anaerobic Toluene- and Ethylbenzene-Degrading Microbial Consortia by PCR-Denaturing Gradient Gel Electrophoresis, RNA-DNA Membrane Hybridization, and DNA Microarray Technology 总被引:11,自引:9,他引:2
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Yoshikazu Koizumi John J. Kelly Tatsunori Nakagawa Hidetoshi Urakawa Saïd El-Fantroussi Saleh Al-Muzaini Manabu Fukui Yoshikuni Urushigawa David A. Stahl 《Applied microbiology》2002,68(7):3215-3225
A mesophilic toluene-degrading consortium (TDC) and an ethylbenzene-degrading consortium (EDC) were established under sulfate-reducing conditions. These consortia were first characterized by denaturing gradient gel electrophoresis (DGGE) fingerprinting of PCR-amplified 16S rRNA gene fragments, followed by sequencing. The sequences of the major bands (T-1 and E-2) belonging to TDC and EDC, respectively, were affiliated with the family Desulfobacteriaceae. Another major band from EDC (E-1) was related to an uncultured non-sulfate-reducing soil bacterium. Oligonucleotide probes specific for the 16S rRNAs of target organisms corresponding to T-1, E-1, and E-2 were designed, and hybridization conditions were optimized for two analytical formats, membrane and DNA microarray hybridization. Both formats were used to characterize the TDC and EDC, and the results of both were consistent with DGGE analysis. In order to assess the utility of the microarray format for analysis of environmental samples, oil-contaminated sediments from the coast of Kuwait were analyzed. The DNA microarray successfully detected bacterial nucleic acids from these samples, but probes targeting specific groups of sulfate-reducing bacteria did not give positive signals. The results of this study demonstrate the limitations and the potential utility of DNA microarrays for microbial community analysis. 相似文献
149.
Hidetoshi Urakawa Peter A Noble Said El Fantroussi John J Kelly David A Stahl 《Applied and environmental microbiology》2002,68(1):235-244
The effects of single-base-pair near-terminal and terminal mismatches on the dissociation temperature (T(d)) and signal intensity of short DNA duplexes were determined by using oligonucleotide microarrays and neural network (NN) analyses. Two perfect-match probes and 29 probes having a single-base-pair mismatch at positions 1 to 5 from the 5' terminus of the probe were designed to target one of two short sequences representing 16S rRNA. Nonequilibrium dissociation rates (i.e., melting profiles) of all probe-target duplexes were determined simultaneously. Analysis of variance revealed that position of the mismatch, type of mismatch, and formamide concentration significantly affected the T(d) and signal intensity. Increasing the concentration of formamide in the washing buffer decreased the T(d) and signal intensity, and it decreased the variability of the signal. Although T(d)s of probe-target duplexes with mismatches in the first or second position were not significantly different from one another, duplexes with mismatches in the third to fifth positions had significantly lower T(d)s than those with mismatches in the first or second position. The trained NNs predicted the T(d) with high accuracies (R(2) = 0.93). However, the NNs predicted the signal intensity only moderately accurately (R(2) = 0.67), presumably due to increased noise in the signal intensity at low formamide concentrations. Sensitivity analysis revealed that the concentration of formamide explained most (75%) of the variability in T(d)s, followed by position of the mismatch (19%) and type of mismatch (6%). The results suggest that position of the mismatch at or near the 5' terminus plays a greater role in determining the T(d) and signal intensity of duplexes than the type of mismatch. 相似文献
150.
Young Man Park Kazuya Matsumoto Yoo Jin Seo Min Jeung Kang Hidetoshi Nagashima 《Biological Rhythm Research》2002,33(1):39-51
The healthy 455 subjects above 60 years of age were questioned on their sleep habit inventory and the morningness-eveningness questionnaire. We analyzed the effects of age and sex on sleep habits and sleep-related trouble. Bedtimes on weekdays and weekends became earlier with aging, and women went to bed significantly later than men did. The length of sleep on weekdays slightly increased with aging, and it was longer for men than for women. The number of urinations and awakenings during nocturnal sleep and the amount of daytime napping increased with aging. The score on morningness-eveningness shifted toward the morning type with aging. In comparison with men, women had significantly longer sleep latency; and a higher percentage of subjects who reported that they sleep for only a short time, have sleep trouble, have received medical treatment for their sleep trouble, and take sleep medication. From these results, we deduced that the phase of sleep shifted forward in subjects above 60 years of age, and they showed frequent interruptions during nocturnal sleep and long daytime napping. We discussed the factor of gender difference in sleep in relation to social and cultural factors, particularly the household activities of women. 相似文献