Biomedical subjects

X C Zhao

Publications and source records attributed to X C Zhao.

3 recordsLinked to original sources

PubMed2002

New macrocyclic diterpenoids from Euphorbia esula.

The structures of two new macrocyclic jatrophane diterpenoid esters from the whole herb of Euphorbia esula, were established as 11,14-epoxy-3beta,5alpha,7beta,8alpha,9alpha,15beta-hexaacetoxy-12-oxo-13alphaH-jatropha-6(17)-ene (1) and 1alpha,3beta-diacetoxy-5alpha,7beta-dibenzoyloxy-9,14-dioxo-11beta,12alpha-epoxy-2alpha,8alpha,15beta-trihydroxy-13betaH-jatropha-6(17)-ene (2) by a combination of 1D- and 2D-NMR techniques as well as UV, IR and mass spectral data. Bioassay evaluation of all isolates against the human tumor cell lines (B16, KB, SMMC and BGC) indicated that ester 2 was cytotoxic to B16 with the IC50 value being 1.81 microg/ml. In addition, the irritant activity assay indicated that both diterpenoids were inactive (ID(24)50 > 100 microg/ear).

Animals↗

PubMed1998

[An algorithm for ECG data compression and its real-time realization with single chip computer].

ECG data compression has been greatly improved since 1960 s. Although the error of compression can be controlled accurately, the reported algorithm at present can not be processed in real-time with a microcomputer. In this paper an algorithm for ECG data compression is expounded which can be realized in real-time with a single chip computer. The algorithm has not only adjustable precision but also an average compression rate of 10.34, especially a pretty high compression ratio for frequent arrhythmic patients.

Algorithms↗

PubMedDate not supplied

Rapid diagnosis of Campylobacter pylori infection by urea test paper.

Antral biopsy specimens from 106 patients were examined by culture, Gram stain and silver stain for Campylobacter pylori. Biopsies were also examined by a urea test paper test (UTPT). Of 106 patients studied C. pylori was detected in 68 (64.2%) by Gram stain, silver stain and culture. The UTPT was positive in 63 (59.4%) specimens. Five had false negative results using the UTPT with no false positive subjects. Thus, UTPT has a sensitivity of 92.6% (63/68) and a specificity of 100%. Of the 63 specimens that were UTPT positive, 45 were positive within 1 min, 58 were positive within 5 min. The remainder became positive between 5 and 15 min. There was a negative correlation between the time required for positive UTPT and the number of C. pylori per pit as seen on silver stained sections (P less than 0.05). UTPT is a rapid and sensitive method for detecting C. pylori in gastric mucosa. This enables early therapy, if indicated, before discharge from hospital. Moreover, the urea test paper method is cheap and easily stored.

Adult↗