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991.
992.
del Refugio Ramos M Jerz G Villanueva S López-Dellamary F Waibel R Winterhalter P 《Phytochemistry》2004,65(7):955-962
Phytochemical investigation of avocado seed material (Persea americana Mill., Lauraceae) resulted in the isolation of two glucosylated abscisic acid derivates. One of these was not known as a natural product and can be regarded as a potential 'missing link' in abscisic acid metabolism in plants. After fractionation by high-speed countercurrent chromatography, and multiple steps of column chromatography, structures were elucidated by 1D-, 2D-NMR, electrospray-MS to be the novel beta-d-glucoside of (1'S,6'R)-8'-hydroxyabscisic acid, and (1'R,3'R,5'R,8'S)-epi-dihydrophaseic acid beta-d-glucoside. Absolute configuration was determined by circulardichroism, optical rotation, and by NOE experiments. 相似文献
993.
Five segments of a large hop plant (Humulus lupulus var. Hallertauer Magnum) carrying several cones were enclosed in sealed glass vessels that were gassed with (18)O(2). After 14 days, the segments were harvested and humulone and cohumulone were analysed by NMR spectroscopy and mass spectroscopy. The oxygen atoms in position 6 of humulone and cohumulone showed 9% (18)O enrichment, respectively. It follows that the C-6 hydroxy groups were introduced by oxygenase catalysis. 相似文献
994.
Hirsch P Mevs U Kroppenstedt RM Schumann P Stackebrandt E 《Systematic and applied microbiology》2004,27(2):166-174
Three cryptoendolithic, aerobic actinomycetes (AA-459T, AA-319 and AA-321) from antarctic sandstone were characterised phenotypically and by molecular taxonomic methods. The isolates had single spores on substrate mycelium, meso-diaminopimelic acid (m-DAP) and glycine (cell wall type II), a whole cell sugar pattern D (galactose, xylose, arabinose, glucose or rhamnose) and phospholipids of type PII (diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol). Their predominant fatty acids were iso-16:0 and iso-15:0 or 17:1omega8c, the menaquinone profile was complex with mainly MK10 (H4) and MK10 (H6). A wide variety of sugars and several acids were utilised for growth. The isolates were sensitive to a few antibiotics, but formation and excretion of antibiotics was not observed. Phenotypically, isolates AA-319 and AA-321 were similar. Phylogenetic analysis of 16S rRNA gene sequences revealed close relationship of strains AA-319 and AA-321 with each other (99.5%) and clustering (98.5%) with Micromonospora coerulea DSM 43143T. DNA-DNA hybridisation showed both strains to be genomically highly similar to strain DSM 43143T. Phenotypically they could be viewed as separate taxa, but presently they will be considered as strains of Micromonospora coerulea. Strain AA-459T was phylogenetically close to Micromonospora chersina DSM 44151T (99.1%) and to Micromonospora rosaria DSM 803T, but DNA-DNA similarity with M. chersina DSM 44151T was low with 28.9/33.5 %, indicating the presence of a different and new species. Consequently, isolate AA-459T (DSM 44398T NRRL B-24248T) is described as the type strain of Micromonospora endolithica sp. nov. 相似文献
995.
Mack F Mojon P Budtz-Jørgensen E Kocher T Splieth C Schwahn C Bernhardt O Gesch D Kordass B John U Biffar R 《Gerodontology》2004,21(1):27-36
Objective: The aim of this study was to describe the oral health status of older adults living in north‐eastern Germany. Materials and Methods: Representative samples of adults aged 60 years or older were examined as part of Study of the Health in Pomerania, a cross‐sectional, population‐based study. Data on 1446 subjects aged 60–79 years were evaluated for coronal caries using the decayed/missing/filled teeth (DMFT) index, root caries using the root caries index (RCI), calculus, plaque, bleeding on probing, pocket depth and attachment loss. Results: The prevalence of edentulousness varied from 16% in the 60–65‐year‐old group to 30% in the 75–79‐year‐old group, whereas the median number of remaining natural teeth per subject varied from 14 in the youngest age group (60–65 years) to one in the oldest (75–79 years). Among subjects aged 60–69 years, a quarter (26%) of the teeth examined had coronal restoration against 17% in the oldest age group (70–79 years). Coronal caries was found in 2% of the teeth in both age groups. Among teeth with gingival recession, 6% had fillings on root surfaces and 2% had root caries, irrespective of age. In all, 11% of the subjects had at least one untreated coronal lesion and 27% had at least one untreated root caries lesion. Plaque score, calculus score and bleeding on probing were higher in the oldest age group (70–79 years). The prevalence of periodontal disease expressed as the presence of at least one periodontal pocket of 4 mm and more, was higher in men and among the younger subjects (men aged 60–69 years: 85% vs. 71% in 70–79‐year‐old men; women aged 60–69 years: 71% vs. 62% in 70–79‐year‐olds). The prevalence of attachment loss of 3 mm or more followed a similar pattern. Conclusions: It seems therefore that in this population, the major oral health concern is related to caries and the small number of teeth retained among the dentate subjects. 相似文献
996.
Martín?C.?Mottura Oliver?GailingEmail author Aníbal?R.?Verga Reiner?Finkeldey 《Plant Molecular Biology Reporter》2004,22(3):251-258
Microsatellites (i.e., simple sequence repeats [SSRs]) are highly variable genetic markers that are widely used at an intraspecific
level in population genetic studies. Here we employed an enrichment strategy for microsatellite isolation by using microsatellite
oligoprobes and magnetic capture of the fragments (Fischer and Bachmann, 1998) inProsopis chilensis (Mol.) Stuntz (Fabaceae). We analyzed the obtained level of enrichment by sequencing 120 enriched genomic fragments. A total
of 521 SSR motives were detected. According to specific search criteria (SSR motifs ≥3 repeat units and ≥6 bp length), 95.8%
of the clones contained SSR motifs. Of these, 7.8% showed homology to chloroplast sequences and 92.2% to nuclear sequences.
When regarding only nuclear SSRs with 5 or more repeat units and a minimum length of 10 bp, the level of enrichment was 30.8%.
A FASTA search against the European Molecular Biology Laboratory (EMBL) database univocally revealed 4 clones in transcribed
regions, 102 clones in genomic regions with unknown function, and 9 clones in chloroplast regions. Among the loci with longer
repeat units (≥10 bp, ≥5 repeat units), 3 were in transcribed regions and 65 were in other genomic regions. We discuss the
applicability of these markers for population genetic studies. 相似文献
997.
Eder S Leierer J Klimaschewski L Wilhelm A Volknandt W Laslop A Fischer-Colbrie R 《Neuro-Signals》2004,13(6):298-307
NESP55 (neuroendocrine secretory protein of M(r) 55,000) is a paternally imprinted proteoglycan, expressed specifically in endocrine cells and the nervous system. We investigated the subcellular localization and secretion of NESP55 in AtT-20 cells. NESP55 accumulated in the medium linearly over 24 h exceeding its intracellular content 3.7-fold by that time. Incubation of cells at 16 degrees C, to block protein export, inhibited basal secretion by 79%. Stimulation of AtT-20 cells with 8-Br-cAMP increased secretion of NESP55 by only 45%. The NESP55 secretory vesicles sedimented at a density of 1.2-1.4 M, which is slightly lighter than that of the large dense core vesicles. Immunofluorescence studies revealed immunoreactivity in the Golgi apparatus and a punctuate staining of processes or neurites. Our data demonstrate that NESP55 is mainly sorted to and released from a population of constitutive secretory vesicles, which are transported out of the perikarya into processes or axons. In addition, some NESP55 is also routed to the regulated pathway. The signal peptide of NESP55, as determined with peptide antisera, is 46 amino acids long and represents the best conserved region of this molecule suggesting that the signal peptide may have a function of its own. The subcellular localization and export of NESP55 from cells are reminiscent of neuronal proteoglycans forming the extracellular matrix, which are implicated in the development and maintenance of neuronal circuits and mechanisms of axonal guidance. 相似文献
998.
Veitia RA 《Genomics》2004,83(3):502-507
A compositional analysis of a sample of 50 zebrafish proteins containing at least one alanine run and of their open reading frames (ORFs) has been performed. The sample of poly(Ala) proteins showed a tendency to have runs of other amino acids (His/H, Gln/Q, Ser/S, Pro/P). Their ORFs and the first and second codon positions had higher GC contents than a reference gene set. The "universal" correlation between the GC content of the first+second and third codon positions (GC1+2 vs GC3) does not hold, but I provide an explanation in terms of genomic heterogeneity. Significant correlation between AHQS content and GC3 was obtained, reflecting codon bias favoring G/C at the third codon position of these amino acids. A correspondence analysis (COA) of relative synonymous codon usage showed that the poly(Ala) proteins have a biased distribution according to the second axis of the COA, which correlates with gene expression in zebrafish. A comparison with human is undertaken. 相似文献
999.
Füth R Herder C Förster S Müller-Scholze S Kruse N Rieckmann P Heinig A Koenig W Scherbaum WA Kolb H Martin S 《Cytokine》2004,27(6):166-172
In clinical practice, diagnosis and risk prediction are usually based on the analysis of serum or plasma proteins whereas gene expression analysis is not used on a routine basis. In order to compare the diagnostic and predictive relevance of serum protein and peripheral blood mRNA levels, we determined cytokine levels of end-stage renal failure patients undergoing hemodialysis. These patients face a high mortality mainly due to acceleration of atherosclerosis and subsequent severe vascular events. mRNA expression of the pro-inflammatory cytokine TNF alpha was significantly elevated in hemodialysis patients and further increased after 2 h of dialysis treatment. In contrast, gene expression of the anti-inflammatory cytokine TGF beta was significantly decreased. Patients who died during the observation period of 36 months had significantly increased mRNA levels of TNF alpha and decreased TGF beta mRNA expression at baseline. Survival analysis indicated that increased TNF alpha mRNA levels (P < 0.02) and TNF alpha/TGF beta mRNA ratios (P < 0.001) predict mortality. The corresponding cytokines in serum showed some association with disease, but serum concentrations neither changed during hemodialysis nor predicted mortality. This study shows that gene expression patterns of circulating leukocytes may present an important new diagnostic tool to predict clinical outcome in patients with inflammatory vascular diseases. 相似文献
1000.
beta-Amyloid efflux mediated by p-glycoprotein 总被引:2,自引:0,他引:2
Lam FC Liu R Lu P Shapiro AB Renoir JM Sharom FJ Reiner PB 《Journal of neurochemistry》2001,76(4):1121-1128
A large body of evidence suggests that an increase in the brain beta-amyloid (Abeta) burden contributes to the etiology of Alzheimer's disease (AD). Much is now known about the intracellular processes regulating the production of Abeta, however, less is known regarding its secretion from cells. We now report that p-glycoprotein (p-gp), an ATP-binding cassette (ABC) transporter, is an Abeta efflux pump. Pharmacological blockade of p-gp rapidly decrease extracellular levels of Abeta secretion. In vitro binding studies showed that addition of synthetic human Abeta1-40 and Abeta1-42 peptides to hamster mdr1-enriched vesicles labeled with the fluorophore MIANS resulted in saturable quenching, suggesting that both peptides interact directly with the transporter. Finally, we were able to directly measure transport of Abeta peptides across the plasma membranes of p-gp enriched vesicles, and showed that this phenomenon was both ATP- and p-gp-dependent. Taken together, our study suggests a novel mechanism of Abeta detachment from cellular membranes, and represents an obvious route towards identification of such a mechanism in the brain. 相似文献