PubMed Health⌕ Search

Biomedical subjects

H L Qin

Publications and source records attributed to H L Qin.

6 recordsLinked to original sources
PubMed2001

[Authentication of traditional Chinese herbal medicines (TCHM) by fingerprints of characteristic general constituents].

OBJECTIVE: To describe the theory, scientific significance, distinguishing features and authentication feasibility of TCHMs by spectral fingerprints of characteristic general constituents. METHOD: Previous relevant investigations and literatures were summed up in the field, and the present situation on the authentication of TCHMs at home and abroad was analysed. RESULT: The characteristic general constituents of TCHMs can be obtained by an appropriate procedure. Their compositions and structures can be determined by spectral fingerprints, especially the 1HNMR fingerprint. The species of TCHMs can be identified accurately by these fingerprints. Besides, the quality of TCHMs can be evaluated by the contents of their GCEs. CONCLUSION: Fingerprint authentication of characteristic general constituents of TCHMs has profound significance for the species identification and quality evaluation of TCHMs.

DNA Fingerprinting↗
PubMed2001

[Assignments of 1HNMR fingerprint of the root bark of Celastrus angulatus].

AIM: To assign the 1HNMR finger-print of the root bark of Celastrus angulatus. METHODS: Silica gel column chromatography was used to separate the chemical constituents of CGE A of the root bark of C. angulatus. The characteristic signals of the 1HNMR finger-print were assigned after determining the structures of the compounds isolated from CGE A. RESULTS: 1HNMR finger-prints of the samples of C. angulatus collected from different regions showed highly characteristic features and reproducibility. Three compounds predominant in CGE A were isolated and their structures were determined by spectral analysis as: angulatin A (1), angulatin B (2) and angulatin C (3). CONCLUSION: Compound 3 is a new compound. Compound 2 was isolated from C. angulatus for the first time. The 1HNMR finger-print of CGE A of the root bark of C. angulatus showed mainly the characteristic signals of the above three compounds and might be utilized for the original authentication of this plant.

Celastrus↗
PubMed1998

Comparative studies on genotoxicity and antigenotoxicity of natural and synthetic beta-carotene stereoisomers.

To evaluate the practical value of natural beta-carotene (NbetaC) and to elucidate the apparent discrepancy between epidemiological observations and intervention trials on the role of beta-carotene (betaC) in tumor prevention, the genotoxicity and the antigenotoxicity of NbetaC and synthetic betaC crystal (SbetaCC) stereoisomers were studied comparatively using chromosome aberration analysis and the micronucleus test in human lymphocytes in vitro. NbetaC was extracted from the halotolerant algae Dunaliella salina. The NbetaC crystal (NbetaCC) preparation is about 70% all-trans (TbetaC) and 8% 9-cis (CbetaC). The NbetaC oil (NbetaCO) preparation is about 40% all-trans and 38% 9-cis. SbetaCC is more than 97% all-trans, and the 9-cis can not be detected. The mixture of betaC (betaCM) preparation is 74% SbetaCC and 26% NbetaC. Our results show no genotoxicity of 1-30 microg/ml NbetaCC, but this concentration of NbetaCC inhibited significantly gamma-ray-induced micronucleus formation in human lymphocytes in vitro. One to thirty microg/ml NbetaCO was most effective against both gamma-ray-induced and spontaneous micronucleus formation. However, no influence of NbetaCO on spontaneous chromosome aberrations in human lymphocytes in vitro was observed. NbetaCO suppressed significantly mitomycin C (MMC)-induced chromosome aberrations. One to thirty microg/ml SbetaCC induced a dose-dependent increase in micronucleus frequency, and also inhibited gamma-ray-induced micronucleus formation. No effect of betaCM on spontaneous chromosome aberrations was found. One to thirty microg/ml betaCM is more effective against MMC-induced chromosome aberrations than NbetaCO. These results suggest that CbetaC might play a critical role in the genotoxicity and antigenotoxicity of SbetaCC and NbetaC. The genotoxic activity of SbetaCC might be involved in carcinogenesis. NbetaC or betaCM could be of practical value in tumor prevention and supplementary treatment.

Adolescent↗
PubMed1998

[Antimutagenic effects of beta-carotene from Dunaliella salina].

AIM: To study the genotoxic and antimutagenic efficts of beta-carotene from Dunaliella salina (beta-CDS). METHODS: The in vitro micronucleus and chromosomal aberration tests in hunman lymphocytes were adopted. The effect of beta-CDS on mutagensis induced by gamma-rays and mitomycin (Mit) was studied. RESULTS: beta-CDS (1-30 mg.L-1) had no genotoxicity, but inhibited spontaneous and gamma-ray-induced micronucleus fromation and Mit-induced chromosomal aberrations in human lymphocytes in vitro. The genotoxic action of synthetic beta-carotene (S beta C) was suppressed, the antimutagenic effects were heightened when S beta C and beta-carotene oil (beta CO, one of the beta-CDS compositions) were mixed in proportion as 80:27.5. CONCLUSION: beta-CDS is an antimutagenic agent.

Adult↗
PubMedDate not supplied

Adenovirus 5 E1a-mediated gene therapy for human ovarian cancer cells in vitro and in vivo.

The aim of this study was to investigate therapeutic efficacy of adenovirus-mediated E1a gene therapy for ovarian cancer in vitro and in vivo. Recombinant replication-deficient adenoviral vectors were prepared by superinfection of 293 cells, and then purified. The efficacy of the adenovirus vector system to infect ovarian cells was tested using different multiplicity of infection (MOI) and different times (1-4) of Ad.RSVlacZ. SKOV-3 cells (10(3) per well) were infected once with 2 x 10(4) adenovirus. The cells were harvested and counted on different days for 7 days to generate the in vitro growth curve. Tumor-bearing mice were injected intraperitoneally with ovarian cancer cells and treated by intraperitoneal injection of 100 microl (2.5 x 10(8) PFU) viral solution containing either replication-deficient Ad.E1a(+); control virus Ad.E1a(-) which is the same adenovirus as Ad.E1a(+) except for E1a deletion, or just phosphate buffered solution. The transduction efficacy increased with higher MOI and reached a plateau at the 20:1 ratio. When Ad.E1a(+) was used to transduce the HER-2/neu overexpressing human ovarian cancer cell line SKOV-3, tumor cell growth in vitro was greatly inhibited by E1a transduction. Also, Ad.E1a+ greatly inhibited tumor growth of SKOV-3-bearing mice. Immunohistochemistry analysis indicated that Ad.E1a protein was expressed in tumor tissue and expression of HER-2/neu p185 protein was suppressed. Very strong beta-gal staining was detected in tumors, and beta-gal activity in small intestine, lung, heart, stomach, liver, and kidney was detected. No beta-gal activity was detected in the tumor and other organs in control mice injected with Ad.E1a(-) or PBS. Adenovirus-type 5 E1a gene can efficaciously inhibit HER-2/neu-overexpressing ovarian cancer, and this promising procedure could greatly benefit ovarian cancer patients with high expression of HER-2/neu.

Adenoviridae↗