ABSTRACT
<p><b>AIM</b>To study the MS/MS fragmentation mechanism of Taxol, and based on it to establish HPLC-ESI-MS/MS technique to separate and identify Taxol in the crude extracts of Taxus cuspidata and its callus culture, consequently to provide a fast and credible method for the analysis of Taxol in natural products.</p><p><b>METHODS</b>Optimized the HPLC-ESI-MS/MS parameters for the sample analysis, and then discussed the ionization and cleavage mechanism of Taxol in ESI-MS and ESI-MS/MS, finally identified the Taxol in the samples with retention time, molecular weight and MS/MS spectra.</p><p><b>RESULTS</b>Elucidated the MS/MS fragmentation mechanism of Taxol, and developed HPLC-ESI-MS/MS method to analyze Taxol in the two samples.</p><p><b>CONCLUSION</b>The HPLC-ESI-MS/MS method is rapid, highly sensitive and specific, so it is suitable for the separation and identification of Taxol in natural products.</p>
Subject(s)
Chromatography, Liquid , Methods , Paclitaxel , Chemistry , Plant Extracts , Chemistry , Plants, Medicinal , Chemistry , Reproducibility of Results , Spectrometry, Mass, Electrospray Ionization , Methods , Tandem Mass Spectrometry , Taxus , ChemistryABSTRACT
In order to fabricate the HLA-DQA1 genotyping chip and develop an integrated, parallel technical platform to type HLA system, a pair of primers and a set of probes were designed according to the sequences of HLA-DQA1 exon 2, where the polymorphism is concentrated. The oligonucleotide chip was made with the methods developed in our laboratory. The target DNA was asymmetrically amplified with the labeled sense primer. The signals were scanned and analyzed after the hybridization between microarray and PCR product. The allele types of the samples were identified. The result was verified by the standard DNA and DNA sequencing. The results showed that the genotyping was successfully carried out in 50 standard DNA samples and 50 clinical samples. Among them, results of the 50 standard DNA samples matched their templates. In the other 50 samples, results of the randomly selected 10 matched their sequencing results except that two of them got the incompletely result. In reproducible tests, the signal reappear rate was 95%. It is concluded that HLA-DQA1 genotyping by using our array system is simple and convenient with satisfied accuracy and reproducibility.
Subject(s)
Humans , Genotype , HLA-DQ Antigens , Genetics , Allergy and Immunology , HLA-DQ alpha-Chains , Oligonucleotide Array Sequence Analysis , Oligonucleotide Probes , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
<p><b>OBJECTIVE</b>To study the relationship between hRad17 mRNA expression and clinicopathologic factors and lymph node metastasis of gastric cancer, and to assess the significance of predicting the extent of lymph node metastasis and prognosis.</p><p><b>METHODS</b>hRad17 mRNA expression was examined in matched primary lesions, normal gastric mucosa and lymph node metastatic lesions among 52 gastric cancer patients by reverse transcription polymerase chain reaction (RT-PCR), polyacrylamide gel electrophoresis (PAGE) and silver stain with the relation between hRad17 mRNA expression and clinicopathologic factors analyzed. At the same time, hRad17 mRNA expressions in 5 gastric benign lesions and SGC7901 gastric carcinoma cell lines were also examined.</p><p><b>RESULTS</b>The primary tumor samples (88.4% positive) showed a significantly higher level of hRad17 expression compared with matched normal tissue (76.9% positive) (P = 0.014), so did the lymph node metastatic samples (94.2% positive) (P = 0.001). The hRad17 mRNA expression showed a low level in benign lesions, but very high in SGC7901 cell line. The hRad17 mRNA expression showed a higher level in patients with the number of lymph node metastasis above 15 than below 15 (P = 0.02), so did the diffused growth than the mass-like growth (P = 0.04).</p><p><b>CONCLUSION</b>The method of PAGE and silver stain can improve the sensitivity of RT-PCR. The degree of lymph node metastasis and invasiveness of carcinoma cells are more serious in cases with hRad17 mRNA overexpression, and extensive lymph node dissection should be carried out for these patients. Examination of hRad17 expression by RT-PCR before surgery is indicated to arrive at an optimum treatment scheme and to estimate the prognosis.</p>