Biomedical subjects

Yong-Guo Li

Publications and source records attributed to Yong-Guo Li.

9 recordsLinked to original sources

PubMed2006

A DNA vaccine against chimeric AFP enhanced by HSP70 suppresses growth of hepatocellular carcinoma.

Alpha-fetoprotein (AFP) is produced principally in fetal liver, gastrointestinal tract and the yolk sac which is temporarily present during embryonic development. AFP is overexpressed in the majority of hepatocellular carcinoma (HCC) and thus offers an attractive target for immunotherapy against this neoplasm. Here, we report that anti-HCC effects were achieved in a therapeutic setting with a DNA vaccine encoding mouse AFP and co-expressing heat shock protein 70 (HSP70) gene. We also demonstrated that this vaccine elicited a marked and highly effective AFP specific CTL response against AFP-positive target cells. This vaccine also induced the prolongation of life span in mice bearing the tumor and the eradication of HCC. It is anticipated that vaccine strategies such as this may contribute to the effective future treatment of hepatocellular carcinoma.

Animals↗

PubMed2005

A validated stability-indicating HPLC with photodiode array detector (PDA) method for the stress tests of Monascus purpureus-fermented rice, red yeast rice.

A stability-indicating reversed phase high-performance liquid chromatography (RP-HPLC) with photodiode array (PDA) detection method was developed and validated for the assay of monacolin series compounds including monacolin K, L, J and their hydroxyl acid forms as well as dehydroxymonacolin K simultaneously in Monascus purpureus-fermented rice, red yeast rice. Well-resolved peaks of seven main compounds of monacolin family were profiled on a C(18) reverse-phase column using a linear gradient of 0.1% trifluoroacetic acid and acetonitrile as the mobile phase, and the detection wavelength was set at 237nm. The method was validated with respect to specificity, chromatographic parameters, linearity, precision, accuracy, limits of detection and quantitation. The stability stress testing for fermented red yeast rice powder was carried out to show the effects of high temperature (80 degrees C), high humidity at room temperature (92.5% RH, 25 degrees C), high humidity at high temperature (75% RH, 60 degrees C) and light (sunlight) in solid state. The results exhibited that monacolins decreased significantly under the conditions of high humidity at high temperature (75% RH, 60 degrees C) and sunlight. Monacolin K and its hydroxyl acid form would be dehydrolyzed and turned to dehydromonacolin K at high temperature (80 degrees C) while the monacolin K, J and L would be transformed into their corresponding hydroxyl acid forms under the condition of high humidity (92.5% RH, 25 degrees C). The indication is that monacolins in red yeast rice powder are light-sensitive and thermal-sensitive. Therefore, it has been suggested that the preparations containing monacolins be stored in the place of cool and lightproof. The proposed degradation pathways were discussed as well. The multi-components assay for stability of botanical products could provide much more information than the normal marker-orientation method.

Chromatography, High Pressure Liquid↗

PubMed2005

Therapeutic effect of autologous dendritic cell vaccine on patients with chronic hepatitis B: a clinical study.

AIM: To investigate the therapeutic effect of autologous HBsAg-loaded dendritic cells (DCs) on patients with chronic hepatitis B. METHODS: Monocytes were isolated from fresh peripheral blood of 19 chronic HBV-infected patients by Ficoll-Hypaque density gradient centrifugation and cultured by plastic-adherence methods. DCs were induced and proliferated in the culture medium with recombinant human granulocyte-macrophage-colony-stimulating factor (rhGM-CSF) and human interleukin-4 (rhIL-4). DCs pulsed with HBsAg for twelve hours were injected into patients subcutaneously twice at intervals of two weeks. Two patients received 100 mg oral lamivudine daily for 12 mo at the same time. HBV-DNA and viral markers in sera of patients were tested every two months. RESULTS: By the end of 2003, 11 of 19 (57.9%) patients had a clinical response to DC-treatment. HBeAg of 10 (52.6%) patients became negative, and the copies of HBV-DNA decreased 10(1.77+/-2.39) on average (t = 3.13, P<0.01). Two cases co-treated with DCs and lamivudine had a complete clinical response. There were no significant differences in the efficient rate between the cases with ALT level lower than 2XULN and those with ALT level higher than 2XULN before treatment (chi(2) = 0.0026). CONCLUSION: Autologous DC-vaccine induced in vitro can effectively suppress HBV replication, reduce the virus load in sera, eliminate HBeAg and promote HBeAg/anti-HBe transformation. Not only the patients with high serum ALT levels but also those with normal ALT levels can respond to DC vaccine treatment, and the treatment combining DCs with lamivudine can eliminate viruses more effectively.

Adolescent↗

PubMed2004

Identification and chemical profiling of monacolins in red yeast rice using high-performance liquid chromatography with photodiode array detector and mass spectrometry.

Monascus purpureus-fermented rice (red yeast rice) was one of the food supplements that had the ability of lowering the blood-lipid levels, and monacolins have been proved to be main active constituents. In total 14 monacolin compounds such as monacolin K (mevinolin), J, L, M, X, and their hydroxy acid form, as well as dehydromonacolin K, dihydromonacolin L, compactin, 3alpha-hydroxy-3,5-dihydromonacolin L, etc. were identified in red yeast rice, using high-performance liquid chromatography with photodiode array detector and tandem mass spectrometry. A chemical fingerprint profiling method to display bioactive monacolins in red yeast rice was established and could be used for the quality control of the target material and its related products. Ten finish products labeled as red yeast rice from different manufacturers in marketing were traced using the chromatographic chemical profiling method, and the results show that only two of them were similar while the other eight were significantly different from the reference red yeast rice. All of these materials including raw material powder and finished products available were quantified and the contents of monacolins were calculated with reference of monacolin K (mevinolin) as the standard.

Chromatography, High Pressure Liquid↗

PubMed2004

Ruggedness/robustness evaluation and system suitability test on United States Pharmacopoeia XXVI assay ginsenosides in Asian and American ginseng by high-performance liquid chromatography.

The work of the ruggedness/robustness evaluation and system suitability tests was oriented to profound understand the practicability of using assay methods issued by United States Pharmacopoeia (USP XXVI and XXVII) for ginsenosides in Asian ginseng and American ginseng. The items chosen for the method validation included quantitative related items such as recovery of Rg(1) and Rb(1), respectively, and qualitative related items such as resolution, theoretical plate number, relative retention time of two critical-band-pairs, Rg(1)/Re and Rb(1) with its neighboring peak, respectively. Totally, 16 column types were used for comparison of different vendors, different packing materials, different size, etc. and five sets of LC systems and two laboratories were involved in comparing the data of both quantitative and qualitative items. The results showed that different packing materials of columns used might significantly alters separation. The column packing material Hypersil afforded the preferable separating for the ginsenosides. No significant difference was observed from the different instrumentations and inter-laboratories. Our results suggest a modification of the system suitability test as given in USP26-NF21 and the latest version of USP27-NF22, which was not suitable for most systems. Using resolutions of Rg(1)/Re and Rb(1) with its neighboring peak as critical parameters for the ginsenosides assay and omitting the relative retention time of both Rg(1)/Re and Rb(1) with its neighboring peak is our suggestion for a more reasonable, yet practicable system suitability. Six typical chromatograms gain from different columns were figured out as well.

Asia↗

PubMed2004

[The detection of nanobacteria infection in serum of healthy Chinese people].

OBJECTIVE: Nanobacteria, a new kind of bacteria found by a Finnish scholar, is considered to relate to many human diseases like nephrolithiasis. However, there are no data available on nanobacteria infection in Chinese people. METHODS: Nanobacteria was detected in serum of 336 cases of healthy adults in Southern China by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry stain. The monoclonal antibody of nanobacterum was supplied by Kuipio University of Finland. RESULTS: Nanobacteria infection rates were 27 (8.0%), 19 (5.7%) in the healthy adults by ELISA and immunohistochemistry stain respectively. No difference was shown between the 2 methods and between male and female, statistically. Age and sex did not seem to be related to the infectious risk of nanobacteria. However, the infectious rate was lower in those below 30-year-old than that of people over 60-year-old (P < 0.05). CONCLUSION: Nanobacteria was existed in the serum of Chinese healthy people with an infectious rate of 8.0%.

Adult↗

PubMed2004

Measurement of des-gamma-carboxy prothrombin levels in cancer and non-cancer tissue in patients with hepatocellular carcinoma.

In a recent experiment, we discovered that liver tissue adjacent to HCC can also produce des-gamma-carboxy prothrombin (DCP). The goal of this study was to advance measurements of DCP levels in hepatocellular carcinoma (HCC) and non-cancer tissues using an electro-chemiluminescence immunoassay (ECLIA) and immunohistochemistry, and to assess their clinical significance. DCP levels in HCC tissues ranged from 0.7 to 209862.4 mAU/0.1 g tissue weight, with a median of 492.6 mAU/0.1 g. DCP levels in non-cancer tissues ranged from 0 to 2329.9 mAU/0.1 g tissue weight, with a median of 88.8 mAU/0.1 g. DCP levels in cell membranes were significantly higher than in the cytoplasm (p<0.001). DCP levels in HCC tissue were significantly higher than in non-cancer tissue (p<0.001). The logarithm of serum DCP levels correlated not only with that of DCP levels in HCC tissues (p=0.019), but also with that in non-cancer tissues (p=0.020), and the total DCP level of liver tissues (p=0.016). The logarithm of DCP levels in HCC tissues correlated with that of DCP levels in non-cancer tissues (p=0.011). DCP levels in HCC tissue with portal vein invasion were significantly greater than in HCC tissues without portal vein invasion (p=0.028). DCP levels in non-cancer tissues with intrahepatic metastatic lesions were significantly higher than in non-cancer tissues without intrahepatic metastatic lesions (p=0.023). Our results suggest that the origin of elevated serum DCP may lie not only in HCC tissue, but in non-cancer tissue. The existence of HCC may influence production of DCP in non-cancer tissue. Tissue DCP may be a prognostic factor, while increased DCP levels in non-cancer tissues may play an important role in hepatocarcinogenesis.

Adult↗

PubMed2004

[Correlative study on the expression of ER mRNA and presenilin 2 in the pancreatic carcinoma tissues].

OBJECTIVE: To study the expression of ER mRNA, presenilin 2 (PS2) and their relationship and clinicopathological significance in the pancreatic carcinoma. METHODS: The assay of ER mRNA was detected by in situ hybridization technique and the expression of PS2 was completed by immunohistochemical method of avidin-biotin complex in the 10% neutral formalin-fixed and routinely paraffin-embedded sections of specimen with pancreatic carcinoma. RESULTS: The positive rate and the score of PS2 were 45.7% and 1.82 +/- 1.34, also those of ER mRNA were 51.4% and 2.08 +/- 1.46 in 35 patients with pancreatic carcinoma. The highly positive correlations were found among the positive rate and the score of ER mRNA and PS2. The positive rate and the score were significantly higher in the cases of well-differentiated adenocarcinoma without metastasis than those in the ones of middle- or poorly-differentiated adenocarcinoma with metastasis. CONCLUSION: The expression of ER mRNA or PS2 might reflect the biological behaviors and hormone-dependent status of pancreatic carcinoma. The assay of ER mRNA and meanwhile the detection of PS2 might have important clinical values for better understanding sex-hormone dependence and raising the therapeutic effect of clinical endocrine therapy of the pancreatic carcinoma.

Adenocarcinoma↗

PubMed2002

[Study on induction of dendritic cells from myeloid leukemia cell lines and their antitumor immune function].

Dendritic cell (DC) plays a key role in antitumor immune response. However, there is a deficiency of DC function in the majority of leukemia patients. It is a novel idea that expanding DC in vitro and enhancing their antitumor immune function and DC-based tumor vaccines may be used as an efficient immune therapy for leukemia. In the project, the condition to induce DC from myeloid leukemia cell lines and its anti-leukemia response were investigated. HL-60, K562 and THP-1 cells were cultured with various combinations of cytokines for inducing DC. The morphologic features were analyzed with optical and electron microscopy. The phenotype of DC was detected by FCM with CD1a, CD40, CD80, CD86, HLA-A, B, C and HLA-DR monoclonal antibodies. The ability of DC stimulating lymphocyte proliferation was observed by allo-mixed lymphocyte reaction using (3)H-TdR incorporation. Cytotoxicity assay was measured by (51)Cr-release method. The level of IL-12 and IFN-gamma in supernatant of DC culture was measured by ELISA. It was proved that the DCs derived from K562, HL-60 and THP-1 cells showed a typical morphology of dendritic cell. The induced cells expressed the surface differentiation antigens of DC. A high expression of phenotypes was found in HL-60-DC and THP-1-DC stimulated by GM-CSF + IL-4 + TNF-gamma and K562-DC with GM-CSF + IL-4 + IL-12. The DCs from the 3 leukemia cell lines stimulated allo-MLR and CTL reaction strongly. Different contents of IL-12 were detected in the supernatants of DC culture and IFN-gamma in the coculture of DC and blood mononuclear cells. It is concluded that the myeloid leukemia cells are able to be induced DCs by cytokines in vitro. The different leukemia cells need different cytokines and cultural conditions. DCs derived from leukemia cells express phenotype of antigen-presenting cells. They have the ability of stimulating T lymphocyte proliferation and inducing CTL reaction to clear leukemia cells, and the DCs secrete IL-12 and increase secretion of IFN-gamma by T cells.

Antigens, CD↗