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Results for “systematic analysis”

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At least 235 records · Page 13Linked to original sources
PubMed1992

Evidence that the systematic analysis of bile cytology permits monitoring of hepatic allograft rejection.

Cytologic analysis was performed on 128 bile specimens collected by schedule from 12 liver transplant recipients over a 4-month period. Clinical diagnoses at the time of specimen collection were determined retrospectively, as follows: clinically stable, 75; acute rejection, 15; CMV hepatitis, 1; systemic infection, 8; ischemic injury, 24 (all within the first 4 days postop); nonclassifiable, 5. Bile analysis was done by a blinded investigator. Specimens contained ductal epithelial cells (EC) and inflammatory cells (IC), which were counted using Cytospin slide preparations. Greater than 10 cells/slide were seen in 93.3% of rejections, 91.7% of ischemic injuries, 100% of systemic infections, and 14.6% of stable patients. In samples collected after POD 4, IC were seen in 86.7% of rejections, yielding a specificity of 94.4% (P less than 0.001). If lymphoblastic cells were also seen, the specificity increased to 96.6%. Five specimens were obtained the day before the clinical diagnosis of rejection; all demonstrated IC. Seven specimens were obtained 3 days after beginning therapy for rejection. In 5 the bile contained no IC, and clinical improvement occurred; in the 2 in whom IC were found, further therapy was subsequently required. IC were seen in 5 of 8 specimens taken when systemic infection was present; the clinical setting allowed differentiation from rejection. Only 1 case of CMV hepatitis was included, thus no conclusions can be drawn for this entity. Cytoplasmic vacuolization of EC was observed in 30% of cases, in these, cyclosporine levels were significantly higher (989.9 +/- 356.9 vs. 672.8 +/- 421.2, P = 0.02). In summary, bile cytology analysis aides in the monitoring of the onset and duration of rejection. It may be an indicator of persistent rejection, and it may help prevent overimmunosuppression in those cases with normal cytological findings.

Antibodies, Monoclonal↗
PubMed2000

Systematic analysis of xanthomonads (Xanthomonas spp.) associated with pepper and tomato lesions.

The taxonomy and evolutionary relationships among members of the genus Xanthomonas associated with tomato and pepper have been a matter of considerable controversy since their original description in 1921. These bacteria, which are a major affliction of tomato and pepper crops in warm and humid regions, were originally described as a single species, but subsequent research has shown the existence of at least two genetic groups differentiated by physiological, biochemical and pathological characteristics. This work synthesizes the findings from several approaches, including pathogenicity tests, enzymic activity, restriction fragment analysis of the entire genome, DNA-DNA hybridization and RNA sequence comparisons based on a 2097 base sequence comprising the 16S rRNA gene, the intergenic spacer located between the 16S and 23S rRNA genes and a small region of the 23S rRNA gene. Within the group of xanthomonads pathogenic on pepper and tomato four distinct phenotypic groups exist, of which three form distinct genomic species. These include Xanthomonas axonopodis pv. vesicatoria (A and C group), Xanthomonas vesicatoria (B group) and Xanthomonas gardneri (D group). On the basis of phenotypic and genotypic differences between A- and C-group strains, the C strains should be considered as a subspecies within Xanthomonas axonopodis pv. vesicatoria.

Antibodies, Monoclonal↗
PubMed1987

Systematic analysis of the long-chain components of Eubacterium lentum.

The cellular long-chain component patterns of 33 strains of Eubacterium lentum were determined by gas chromatography. Two main types of long-chain component patterns were distinguished. The first (26 strains) was characterized by saturated branched-chain fatty acids (br14:0, br15:0, br16:0 and br17:0). The second (7 strains) did not contain branched-chain fatty acids and was characterized by saturated straight-chain fatty acids (11:0, 12:0, 14:0 and 16:0). Both types contained fatty aldehydes and their respective dimethyl acetals (14ald and 14dma, 16ald and 16dma). br16dma was only found in the first type. The G + C content of the DNA (Tm) of the 33 strains varied between 63.7 and 69.1 mol %. Canonical correlation analysis distinguished three subtypes within the first main type.

Base Composition↗
PubMed1995

Systematic analysis of coding and noncoding DNA sequences using methods of statistical linguistics.

We compare the statistical properties of coding and noncoding regions in eukaryotic and viral DNA sequences by adapting two tests developed for the analysis of natural languages and symbolic sequences. The data set comprises all 30 sequences of length above 50 000 base pairs in GenBank Release No. 81.0, as well as the recently published sequences of C. elegans chromosome III (2.2 Mbp) and yeast chromosome XI (661 Kbp). We find that for the three chromosomes we studied the statistical properties of noncoding regions appear to be closer to those observed in natural languages than those of coding regions. In particular, (i) a n-tuple Zipf analysis of noncoding regions reveals a regime close to power-law behavior while the coding regions show logarithmic behavior over a wide interval, while (ii) an n-gram entropy measurement shows that the noncoding regions have a lower n-gram entropy (and hence a larger "n-gram redundancy") than the coding regions. In contrast to the three chromosomes, we find that for vertebrates such as primates and rodents and for viral DNA, the difference between the statistical properties of coding and noncoding regions is not pronounced and therefore the results of the analyses of the investigated sequences are less conclusive. After noting the intrinsic limitations of the n-gram redundancy analysis, we also briefly discuss the failure of the zeroth- and first-order Markovian models or simple nucleotide repeats to account fully for these "linguistic" features of DNA. Finally, we emphasize that our results by no means prove the existence of a "language" in noncoding DNA.

Animals↗
PubMed2005

Systematic analysis of group identification in stock markets.

We propose improved methods to identify stock groups using the correlation matrix of stock price changes. By filtering out the market-wide effect and the random noise, we construct the correlation matrix of stock groups in which nontrivial high correlations between stocks are found. Using the filtered correlation matrix, we successfully identify the multiple stock groups without any extra knowledge of the stocks by the optimization of the matrix representation and the percolation approach to the correlation-based network of stocks. These methods drastically reduce the ambiguities while finding stock groups using the eigenvectors of the correlation matrix.

Journal Article↗