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41.
We evaluated antibody-coated bacteria (ACB) in expectorated sputum to discriminate contaminating or colonizing organisms from true pathogens. We examined 60 expectorated sputum samples from 51 patients with lower respiratory infections (chronic obstructive pulmonary disease 25, pneumonia 20, purulent tracheobronchitis 6). All samples were examined with quantitative culture and immunofluorescent demonstration of ACB. From the results of quantitative culture, we divided specimens into pathogen-isolated and pathogen-free samples. Among pathogen-isolated samples, in which we isolated accepted pathogenic organisms at ≥ 107 colony-forming units per ml, 16 of 23 samples were ACB-positive (69.5%). In contrast, among pathogen-free samples, in which we isolated accepted pathogens at < 107 colony forming units per ml or only upper respiratory flora, only 3 of 37 samples were ACB-positive (8.1%). The ACB-positive rate was significantly higher in pathogen-isolated than in pathogen-free samples (P < 0.001). Consequently, detecting ACB in expectorated sputum shows good potential as another criterion for distinguishing contaminating or colonizing organisms from true pathogens.  相似文献   
42.
The flowering response of axillary buds of seedlings of Pharbitis nil Choisy, cv. Violet, was examined in relation to the timing of apical bud removal (plumule including the first leaf or second leaf) before or after a flower-inductive 16-h dark period. When the apical bud was removed well before the dark period, flower buds formed on the axillary shoots that subsequently developed, but when removed just before, or after, the dark period, different results were observed depending on the timing of the apical bud removal and plant age. In the case of 8-day-old seedlings, fewer flower buds formed on the axillary shoots developing from the cotyledonary node when plumules were removed 20 to 0 h before the dark period. When the apical bud was removed after the dark period, no flower buds formed. Using 14-day-old seedlings a similar reduction of flowering response was observed on the axillary shoots developing from the first leaf node when the apical bud was removed just after the dark period. To further elucidate the relationship between apical dominance and flowering, kinetin or IAA was applied to axillary buds or the cut site where the apical bud was located. Both chemicals influenced flowering, probably by modulating apical dominance which normally forces axillary buds to be dormant.  相似文献   
43.
To evaluate the effects of exercise on aortic wall elasticity and elastic components, young male rats underwent various exercise regimes for 16 weeks. In the exercised rats, the aortic incremental elastic modulus decreased significantly when under physiological strain. The aortic content of elastin increased significantly and the calcium content of elastin decreased significantly in the exercised group. The accumulated data from the exercised and sedentary groups revealed that the elastin calcium content was related positively to the incremental elastic modulus. We concluded that physical exercise from an early age decreases the calcium deposit in aortic wall elastin and that this effect probably produced in the exercised rats a distensible aorta.  相似文献   
44.
Severe familial amyloid cardiomyopathy (FAC) in a Danish kindred is associated with a specific mutation (Met for Leu 111) in the transthyretin (TTR) gene. The mutation causes the loss of a DdeI restriction site in the gene, allowing molecular diagnostic studies. We studied formalin-fixed, paraffin-embedded tissues, up to 39 years old, from 29 family members of this kindred. DNA was partially purified from deparaffinized tissue sections and a DNA sequence of the TTR gene flanking the mutation site was amplified by the polymerase chain reaction (PCR), followed by restriction enzyme analysis. Amplified DNA was obtained from tissues representing 23 of the 29 persons. Ten out of the 23 family members were found to carry the TTR Met 111 mutation, whereas 13 were not affected. The results were consistent with known clinical data and with corresponding serum TTR examinations. This retrospective study shows that archival tissues can be used to confirm the diagnosis and disease pattern in members of families affected by hereditary diseases.  相似文献   
45.
Transformation of pecan and regeneration of transgenic plants   总被引:5,自引:0,他引:5  
A gene transfer system developed for walnut (Juglans regia L.) was successfully applied to pecan (Carya illinoensis [Wang] K. Koch). Repetitively embryogenic somatic embryos derived from open-pollinated seed of Elliott, Wichita, and Schley were co-cultivated with Agrobacterium strain EHA 101/pCGN 7001, which contains marker genes for beta-glucuronidase activity and resistance to kanamycin. Several modifications of the standard walnut transformation techniques were tested, including a lower concentration of kanamycin and a modified induction medium, but these treatments had no measurable effect on efficiency of transformation. Nineteen of the 764 viable inoculated embryos produced transgenic subclones; 13 of these were from the line Elliott6, 3 from Schley5/3, and 3 from Wichita9. Transgenic embryos of Wichita9 germinated most readily and three subclones were successfully micropropagated. Three transgenic plants of one of these subclones were obtained by grafting the tissue cultured shoots to seedling pecan rootstock in the greenhouse. Gene insertion, initially detected by GUS activity, was confirmed by detection of integrated T-DNA sequences using Southern analysis.  相似文献   
46.
The aqueous two-phase partitioning technique was utilized to isolate a plasma membrane (PM) fraction from etiolated seedlings of Arabidopsis thaliana. The purification procedure adopted yielded a fraction highly enriched in PM as compared to inner membranes, with a recovery of about 30%, as judged from the activities of PM markers such as vanadate-sensitive ATPase, FC binding and UDP-glucose sterol glucosyltransferase. The purified PM fraction displayed vanadate-sensitive H+ pumping activity. Its purity was confirmed by the biochemical characteristics of its ATPase activity assayed in the absence of Ca2+: sensitivity to vanadate (IC50 ca. 1 μM), Mg2+-dependence, insensitivity to molybdate, oligomycin and nitrate, pH optimum at 6.6. The PM H+-ATPase activity was stimulated by fusicoccin and by a controlled treatment of the PM with trypsin. In both cases stimulation was much stronger on the activity assayed at pH 7.5 than on the activity at pH 6.6. Moreover, neither fusicoccin nor the treatment with trypsin stimulated the portion of activity (30 to 40% at pH 7.5) which decayed upon preincubation of the PM in assay medium without ATP.  相似文献   
47.
Fossil wood assemblages deposited during 6.300–3.000 yBP, are studied at the Akayama Site, central Japan. Layer III containing fossil woods was divided into three subunits according to intercalating tephras, and total 3618 fossil woods were studied. In the composition, deciduous broad-leaved trees dominated, accompanied by some evergreen conifers. In the diameter distribution, nine taxa accounted for nearly 90% of individuals exceeding 10 cm in diameter. Spatial distribution of nine major and three minor taxa and that of thick individuals clarified the following points: 1)Fraxinus established a lowland forest during 5,000–4,500 yBP, accompanied byAlnus sect.Gymnothyrsus, Acer andAesculus turbinata; 2) small trees ofAlnus sect.Gymnothyrsus extensively intermingled in the lowlandFraxinus forest during 4,500–3,000 yBP; 3)Quercus sect.Prinus and Castanea crenata constituted escarpment forests during 6,300–3,000 yBP; 4)Carpinus sect.Eucarpinus became a major component during 5,000–4,500 yBP, andOstrya japonica replacedCastanea crenata during 4,500–3,000 yBP. Comparison with the other five contemporaneous fossil wood assemblages shows prevalence ofFraxinus-dominant forests during the Late to Latest Jomon Periods in the southern part of the Kanto Plain.  相似文献   
48.
The expression and promoter activity of genes for isozymes ofhorseradish peroxidase, namely, prxCla, prxClb, prxC2 and prxC3,were studied. Organ-specific expression of these genes in horseradishplants was examined by Northern blot analysis. The group ofprxCl genes was expressed mostly in stems, while prxC2 and prxC3were expressed to a greater extent in roots. Hardly any expressionof any of the genes was detected in leaves. In transient-expressionassays with tobacco protoplasts, about 500 bp of the 5'-noncodingregions of each of the genes, ligated to the gene for ß-glucuronidase(GUS), exhibited significant promoter activity. In particular,the fragments extending from the initiation codon of the prxC2gene to –529 bp and –1 kbp supported high levelsof GUS activity, which were 4.4 and 11.4 times respectively,the activity observed under control of the 35S promoter fromcauliflower mosaic virus (CaMV). Conserved enhancer sequencesof human genes were found in the 5'-flanking region of prxC2,and deletion of the regions that contained the enhancer sequencesreduced the GUS activity. High levels of GUS activity were observedin transgenic tobacco plants that contained 1 kbp of the 5'flanking region of prxC2 fused to the GUS gene. GUS activitywas diminished when deletion from the 5' end extended as faras the CAAT box. No significant organ-specific expression ofGUS was observed with any such deletion. (Received April 15, 1992; Accepted September 11, 1992)  相似文献   
49.
The electrical potential distribution has been measured preciselyaround the root surface of the bean sprout Vigna mungo (L) Hepper.A large negative potential well was found at the growth portionof the root tip. Also, in the matured region of the root, wefound a negative potential well at an unspecified position inspite of the fact that nothing was detected on the smooth surface.A lateral root emerge was found to have initiated after 15–20hours just at the position corresponding to the potential well.With the expectation that these potentials can be elucidatedbased on the transport of ions which are released or absorbedby the root as a result of cell activity, we precisely measuredthe concentrations of major ion species (K+, H+, and Cl)around the root. The theoretical potential distribution curvesobtained by putting all the concentration data into the Henderson'sEquation for a liquid junction (diffusion) potential coincidedwell with the experimental curves. (Received October 24, 1994; Accepted March 24, 1995)  相似文献   
50.
Glycinebetaine is one of the compatible solutes that accumulate in the chloroplasts of certain halotolerant plants when these plants are exposed to salt or cold stress. The codA gene for choline oxidase, the enzyme that converts choline into glycinebetaine, has previously been cloned from a soil bacterium, Arthrobacter globiformis. Transformation of Arabidopsis thaliana with the cloned codA gene under the control of the 35S promoter of cauliflower mosaic virus enabled the plant to accumulate glycinebetaine and enhanced its tolerance to salt and cold stress. At 300 mM NaCl, considerable proportions of seeds of transformed plants germinated well, whereas seeds of wild-type plants failed to germinate. At 100 mM NaCl, transformed plants grew well whereas wild-type plants did not do so. The transformed plants tolerated 200 mM NaCl, which was lethal to wild-type plants. After plants had been incubated with 400 mM NaCl for two days, the photosystem II activity of wild-type plants had almost completely disappeared, whereas that of transformed plants remained at more than 50% of the original level. When exposed to a low temperature in the light, leaves of wild-type plants exhibited symptoms of chlorosis, whereas those of transformed plants did not. These observations demonstrate that the genetic modification of Arabidopsis thaliana that allowed it to accumulate glycinebetaine enhanced its ability to tolerate salt and cold stress.  相似文献   
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