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Zhen Liang

Publications and source records attributed to Zhen Liang.

16 recordsLinked to original sources
PubMed2006

Separation and identification of compounds in Adinandra nitida by comprehensive two-dimensional liquid chromatography coupled to atmospheric pressure chemical ionization source ion trap tandem mass spectrometry.

A comprehensive two-dimensional liquid chromatographic (2D-LC) separation system based on the combination of a CN column and a Merck Chromolith Flash reversed-phase column was developed for the separation of components in Adinandra nitida, one type of traditional Chinese medicine (TCM). The two dimensions were connected by a ten-port, dual-position valve controlled automatically by software written in-house. The effluents were detected by both ultraviolet and atmospheric pressure chemical ionization source ion trap tandem mass spectrometry (MS). The calculated peak capacity of the 2D-LC-MS/MS system was above 1240. More than 57 components were resolved in the methanol extract from Adinandra nitida leaves, and five of these were identified based on their relative retention times, molecular weights and MS/MS spectra.

Chromatography, High Pressure Liquid↗
PubMed2006

Macroporous polyacrylamide-based monolithic column with immobilized pH gradient for protein analysis.

Monolithic materials were prepared in capillaries by in situ polymerization of acrylamide, glycidyl methacrylate, and N,N'-methylenebisacrylamide in the presence of 1,4-butanediol, dodecanol, and DMSO as porogens. With Ampholine attached to the surface of the porous monolith via epoxide groups, a monolithic-IPG (M-IPG) was formed and showed good mechanical and chemical stability. With such a column immobilized by Ampholine 3.5-10, IEF-MIX 3.6-9.3 was separated and good linearity was obtained. The CIEF behavior of M-IPG was evinced by comparing the current with that in the open tubular capillary. In addition, the protein mixtures excreted from lung cancer cells of rats were analyzed with such a new M-IPG column.

Acrylic Resins↗
PubMed2006

On-line hyphenation of supercritical fluid extraction and two-dimensional high performance liquid chromatography-atmospheric pressure chemical ionization tandem mass spectrometer for the analysis of Ganoderma lucidum.

A novel on-line system combining supercritical fluid extraction (SFE) and two-dimensional high performance liquid chromatography (2D-HPLC) was developed. A trap column and two three-port valves were employed to couple SFE and 2D-HPLC system, which was composed of a CN column and a monolithic silica column, connected by a 10-port dual-position valve. The analytes extracted by supercritical CO2 were completely transferred to the 2D-HPLC system. After separation in two orthogonal modes, the eluents were delivered to APCI-tandem-MS for identification of the samples. In this way, sample preparation, separation, detection, and identification were integrated into an on-line system permitting analysis of the fruiting bodies of Ganoderma lucidum, and at least 73 components in the extract were resolved with calculated peak capacity of up to 1643.

Acetonitriles↗
PubMed2006

Rapid protein identification using monolithic enzymatic microreactor and LC-ESI-MS/MS.

A monolithic enzymatic microreactor was prepared in a fused-silica capillary by in situ polymerization of acrylamide, glycidyl methacrylate (GMA) and ethylene dimethacrylate (EDMA) in the presence of a binary porogenic mixture of dodecanol and cyclohexanol, followed by ammonia solution treatment, glutaraldehyde activation and trypsin modification. The choice of acrylamide as co-monomer was found useful to improve the efficiency of trypsin modification, thus, to increase the enzyme activity. The optimized microreactor offered very low back pressure, enabling the fast digestion of proteins flowing through the reactor. The performance of the monolithic microreactor was demonstrated with the digestion of cytochrome c at high flow rate. The digests were then characterized by CE and HPLC-MS/MS with the sequence coverage of 57.7%. The digestion efficiency was found over 230 times as high as that of the conventional method. In addition, for the first time, protein digestion carried out in a mixture of water and ACN was compared with the conventional aqueous reaction using MS/MS detection, and the former solution was found more compatible and more efficient for protein digestion.

Animals↗
PubMed2006

[Clinical analysis of 123 gastric cardia carcinoma patients treated with surgical operation].

BACKGROUND & OBJECTIVE: The prevalence of gastric cardia carcinoma is increasing in recent decades, necessitating further research on it. However, there are still debates on its clinical management. This study was to summarize our experiences in surgical treatment of gastric cardia carcinoma. METHODS: A total of 123 gastric cardia carcinoma patients, received surgical operation, were divided into 3 groups according to surgical approaches: 72 in thoracic group, 40 in abdominal group, and 11 in thoracoabdominal group. Clinical data, including preoperative examination, surgical approach, lymph node dissection, and postoperative pathology, of the patients were analyzed. RESULTS: Setting pathologic results as golden standard, the correct diagnosis rates of preoperative ultrasound for serosal involvement, lymph node metastasis, distal esophageal involvement, and others (including liver metastases, extended invasion, and ascites) were 71.2%, 62.2%, 47.8%, and 100%, respectively; those of CT were 78.6%, 72.7%, 51.9%, and 100%, respectively. Endoscopy could indicate the distance between tumor and incisor, and barium meal showed the relationship between tumor and diaphragm. The curative resection rate was 94.3% (116/123); among the 116 cases, 108 (93.1%) were adenocarcinoma, 2 were squamous cell carcinoma, 2 were adenosquamous carcinoma, 2 were atypical carcinoid, and 2 were carcinoid; 84 (72.4%) had abdominal lymph node metastases, 6 (7.1%) had thoracic lymph node metastases, and 40 (34.5%) had distal esophageal involvement. CONCLUSIONS: Preoperative abdominal ultrasound and thoracoabdominal CT scan are helpful in evaluating respectability of gastric cardia carcinoma. Endoscopy and barium meal may be helpful in deciding the surgical approach. Abdominal lymph node is the main route of lymphatic dissemination of gastric cardia carcinoma. The efficacies of the 3 surgical approaches are similar; each has its benefit. Surgical modalities should be carried out individually according to Siewert classification and patient's conditions.

Adenocarcinoma↗
PubMed2006

[Evaluation of first phase insulin secretion by a nateglinide-intravenous glucose insulin release test in newly diagnosed type 2 diabetics].

OBJECTIVE: To evaluate the function of the first phase of insulin secretion of pancreatic B cells in newly diagnosed type 2 diabetics using nateglinide-intravenous glucose insulin release test (NG-IVGIRT). METHODS: NG-IVGIRT and intravenous glucose insulin release test (IVGIRT) were done in 8 patients with newly diagnosed type 2 diabetes mellitus and NG-IVGIRT was done in 8 normal people. Insulin and glucose of blood were determined at - 15, 0, 2, 4, 6, 8 and 10 min in NG-IVGIRT or IVGIRT. RESULTS: The response of 0 - 10 min insulin to NG-IVGIRT was significantly higher than that to IVGIRT in the diabetics. The response of insulin to NG-IVGIRT in the normal controls was much higher than that in the diabetics. The area under curve (AUC) of insulin to NG-IVGIRT was apparently elevated and the AUC of glucose to NG-IVGIRT reduced in the normal controls as compared with those in the diabetics. CONCLUSION: The results indicated that the reserve of first phase insulin secretion in newly diagnosed type 2 diabetics could be provoked in some degree by NG-IVGIRT and there was a big difference in the reserve of the first phase of insulin secretion provoked by NG-IVGIRT between newly diagnosed type 2 diabetics and normal people.

Adult↗
PubMed2006

[Separation and identification of Taxol in the crude extracts of Taxus cuspidata and its callus culture with HPLC-ESI-MS/MS].

AIM: 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. METHODS: 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. RESULTS: Elucidated the MS/MS fragmentation mechanism of Taxol, and developed HPLC-ESI-MS/MS method to analyze Taxol in the two samples. CONCLUSION: 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.

Chromatography, Liquid↗
PubMed2005

Rapid protein digestion and identification using monolithic enzymatic microreactor coupled with nano-liquid chromatography-electrospray ionization mass spectrometry.

A novel monolithic enzymatic microreactor was prepared in the fused-silica capillary by in situ polymerization of acrylamide (AA), N-acryloxysuccinimide (NAS) and ethylene dimethacrylate (EDMA) in the presence of a binary porogenic mixture of dodecanol and cyclohexanol, which could offer very low back pressure, enabling the fast digestion of proteins. The performance of the monolithic microreactor was demonstrated by digesting cytochrome c at high flow rate, and the comparisons between the in-solution digestion and on-column reaction were made by a nano-high performance liquid chromatography-mass spectrometry (nano-HPLC-MS) system. The performance of the monolithic microreactor was demonstrated with the digestion of cytochrome c at the fast flow rate of 1 microL/min, which afforded a residence time of 7s, yielding a sequence coverage of 54.81% using strict multiple database searching thresholds. Future more, a mixture of four standard proteins was digested and analyzed using the on-line digestion and nano-HPLC-MS system. The results showed the promising of such a system in the analysis of protein mixture.

Bioreactors↗
PubMed2005

Purification of human tissue prokallikrein excreted from insect cells by liquid chromatography.

Tissue kallikrein, generally existing in living bodies as prokallikrein, is a serine proteinase that has proven of great significance to treat hypertension, cardiopathy and nephropathy. Although the extraction of tissue kallikrein from human urine is the most commonly used method to obtain such a protein, not only the yield is very little, but also the procedure is rather complex. Furthermore, the biological safety is uncertain. Therefore, the preparation of such a protein by genetic engineering method, including gene expression, cell culture, separation and purification, is very important. In this paper, a new method to obtain purified tissue prokallikrein excreted from insect cells by liquid chromatography has been proposed. In contrast to the previously published papers, the purification procedure is simplified to only three steps with the final yield of 57% and the purity of 95%, which is not only convenient, but also low-cost and suitable for the large-scale preparation of such a protein. The purified protein is further validated as prokallikrein by high performance liquid chromatography-mass spectrometry and amino acid sequencing.

Animals↗
PubMed2005

[Abnormal expression of Thy-1 as a novel tumor marker in lung cancer and its prognostic significance].

OBJECTIVE: The purpose of this study was to investigate the expression of Thy-1 immunohistochemically in different lung tumors and its prognostic significance in non-small cell lung cancer (NSCLC) cases. We also evaluate relationship between Thy-1 and p53 expression status so as to find any clue about the mechanism. METHODS: In this study, we used anti-Thy-1/CD90 antibody to detect the expression pattern of Thy-1 in different lung tumor sections, which were embedded in paraffin blocks. The expressions of Thy-1 in 175 lung tissue cases, including different pathological types, were analyzed as tissue array form. We also detect expression status in 91 NSCLC among these cases and analyze the relationship between Thy-1 and p53. The relationship between Thy-1 expression and patients' survival was studied. RESULTS: We first found that anti-Thy-1 antibody can strongly stain a nuclear molecule in different type of lung cancer cells. Among lung cancer cases, 89 (56.7%) cases showed strong nuclear staining for Thy-1 specially. In univariate and multivariate analysis for 91 NSCLC patients we found TNM staging, lymph node status and Thy-1 overexpression in nuclei were independent factors to affect the prognosis of NSCLC patients. In lymph node non metastasis subgroup cases, Thy-1 negative patients had significant longer survival than Thy-1 positive cases (mean survival: 46.42 mons vs 38.56 mons, P = 0.0207). There was a significant association between Thy-1 and p53 expression (P < 0.0001). CONCLUSION: There is a significant overexpressed Thy-1 located in lung cancer cell nucleus as compared to the normal tissue or benign tumor cells of lung, and it is one of the factors effected on the prognosis of NSCLC patients. This finding suggests that Thy-1 maybe a novel latent malignant marker in the lung cancer pathology. The association between Thy-1 and p53 expression in nucleus suggests that p53 protein and Thy-1 may have some interaction.

Adult↗
PubMed2005

On-line concentration of proteins in pressurized capillary electrochromatography coupled with electrospray ionization-mass spectrometry.

Pressurized capillary electrochromatography (pCEC) and electrospray ionization-mass spectrometry (ESI-MS) have been hyphenated for protein analysis. Taken cytochrome c, lysozyme, and insulin as samples, the limits of detection (LODs) for absolute concentrations are 10(-11) mol (signal-to-noise ratio S/N = 3) with relative standard deviations (RSDs) of retention time and peak area, respectively, of less than 1.7% and 4.8%. In order to improve the detection sensitivity, on-line concentration by field-enhanced sample-stacking effect and chromatographic zone-sharpening effect has been developed, and parameters affecting separation and detection, such as pH and electrolyte concentration in the mobile phase, separation voltage, as well as enrichment voltage and time, have been studied systematically. Under the optimized conditions, the LODs of the three proteins could be decreased up to 100-fold. In addition, the feasibility of such techniques has been further demonstrated by the analysis of modified insulins at a concentration of 20 microg/mL.

Chromatography, Micellar Electrokinetic Capillary↗
PubMed2005

[The expression of 11 cancer/testis (CT) antigen genes in esophageal carcinoma].

OBJECTIVE: To investigate the expression status of 11 different cancer/testis (CT) antigen genes in esophageal carcinoma. METHODS: Esophageal carcinoma tissue and adjacent normal esophageal mucosa taken from 35 esophageal carcinoma patients were assayed for the expression of 11 different CT antigen genes by RT-PCR techniques. RESULTS: Of the 11 CT antigen genes analyzed, none of them was expressed in normal esophageal mucosa. MAGE-3 was found to be the most frequently expressed in esophageal carcinoma tissues (62.9%), followed, in the order of expression frequency, by MAGE4 (31.4%), LAGE-1 (28.6%), MAGE-1 (25.7%), CT10 (20.0%), NY-ESO-1 (20.0%), CT7 (5.7%) and SCP1 (2.9%). No expression of SSX-1, SSX-2 and SSX-4 was found. Among the 35 cases, 28 (80.0%) expressed at least one CT antigen gene, 21 (60.0%) expressed more than 2 CT antigen genes, and 4 of the 21 (19.0%) expressed more than 4 CT antigens, which accounted for 11.4% of total number of patients (4/35). No CT antigen expression was found in the tumor tissue in 7 cases, including 5 cases in stage II and 1 case each in stage I and IV, respectively. Of the 11 CT genes examined, expression of 5 genes (NY-ESO-1, LAGE-1, MAGE-1, MAGE-3 and MAGE-4) was correlated with tumor progression. SCP-1 and CT10 expression was found more frequently in early stage patients. With progression of the disease, the frequency of co-expression of multiple CT antigen genes was significantly increased reaching 28.6% in stage III patients. CONCLUSION: Of the 11 different CT antigen genes examined by RT-PCR in esophageal carcinoma, 8 genes were detected in various frequencies in 28 of the 35 esophageal cancer patients studied. They are candidate tumor-associated antigens in the preparation of tumor vaccines for immunotherapy in esophageal cancer patients.

Adult↗
PubMed2004

Pressurized electrochromatography coupled with electrospray ionization mass spectrometry for analysis of peptides and proteins.

Pressurized capillary electrochromatography (pCEC) was coupled with electrospray ionization mass spectrometry (ESI-MS) using a coaxial sheath liquid interface. It was used for separation and analysis of peptides and proteins. The effects of organic modifier and applied voltage on separation were investigated, and the effects of pH value of the mobile phase and the concentration of the electrolyte on ESI-MS signal were investigated. The resolution and detection sensitivity with different separation methods (pCEC, capillary high-performance liquid chromatography) coupled on-line with mass spectrometry were compared for the separation of a peptide mixture. To evaluate the feasibility and reliability of the experimental setup of the system, tryptic digests of cytochrome c and modified protein as real samples were analyzed by using pCEC-ESI-MS.

Electrochemistry↗
PubMed2004

[Expression of multiple cancer-testis antigen genes in non-small cell lung cancer treated by chemotherapy prior surgery].

OBJECTIVE: To investigate the possibility of utilizing cancer-testi (CT) antigens as targets for immunotherapy of non-small cell lung cancer (NSCLC) with vaccines. METHODS: Tissues from 51 NSCLC patients who had chemotherapy prior surgery were assayed for the expression of 11 different CT antigens by RT-PCR. RESULTS: Of the 11 CT antigens analyzed, MAGE-3 was found to be expressed most frequently in NSCLC tissues and CT7 the least frequently. The frequencies of CT antigen expression was: MAGE-3 (38%), NY-ESO-1 (21%), CT10 (17%), LAGE-1 (15%), MAGE-4 (13%), SCP-1, SSX1 and SSX4 (12%), MAGE-1 (10%), SSX2 (6%), and CT7 (2%). Among these cases, 34 (67%) expressed at least one CT antigen gene. 13 of the 17 cases in which no CT antigen expression was found in the tumor tissue, the tumors were classified as at the stage I. MAGE-3 and CT10 were found to be expressed more frequently in tissues from patients with late stage diseases while SCP-1 was found more frequently in earlier stages of NSCLC. CT expression was more frequently found in squamous cell carcinoma than in adenocarcinoma. CONCLUSIONS: (1) Cancer vaccines with CT antigens including MAGE-3, NY-ESO-1, LAGE-1, etc, are suitable for immunotherapy of NSCLC after chemotherapy and surgery. (2) NSCLC patients at different stages of disease may be treated with vaccines of different CT antigen composition. (3) CT antigen vaccines are most attractive for patients with late stage NSCLC and/or squamous cell carcinoma of NSCLC.

Antigens, Neoplasm↗
PubMed2003

Melatonin in Chinese medicinal herbs.

Melatonin is a highly conserved molecule that not only exists in animals, but also is present in bacteria, unicellular organisms and in plants. Since melatonin is an antioxidant, in plants melatonin was speculated to protect them from intrinsic and environmental oxidative stress. More importantly, melatonin in edible plants inevitably enters animals and human through feed and food. In this study, more than 100 Chinese medicinal herbs were analyzed using the methods of solid phase extraction and HPLC-FD on-line with MS to determine whether melatonin is present in these commonly used herbs. Melatonin was detected in majority of these plants. Sixty-four of them contain melatonin in excess of 10 ng per gram dry mass. Melatonin levels in several herbs are in excess of 1000 ng/g. It is well known that normal average physiological plasma levels of melatonin are only 10-60 pg/mL. These high level-melatonin containing plants are traditionally used to treat diseases which presumably involve free radical damage. The current study provides new information concerning one potentially effective constituent present in a large number of medicinal herbs. The results suggest that these herbs should be reevaluated in reference to their nutritional and medicinal value.

Antioxidants↗