Biomedical subjects

Minghui Huang

Publications and source records attributed to Minghui Huang.

13 recordsLinked to original sources

PubMed2006

Methyl protodioscin induces G2/M cell cycle arrest and apoptosis in HepG2 liver cancer cells.

Methyl protodioscin (NSC-698790) is one of the main bioactive components in the traditional Chinese medicine Dioscorea collettii var. hypoglauca (Dioscoreaceae). In this study, we investigated the anti-proliferative effect of methyl protodioscin on the HepG2 cells and the mechanism of the induced cytotoxicity. Treatment of methyl protodioscin resulted in G2/M arrest and apoptosis in HepG2 cells. These effects were attributed to down-regulation of Cyclin B1 and the signaling pathways leading to up-regulation of Bax and down-regulation of BCL2, suggesting that methyl protodioscin may be a novel anti-mitotic agent.

Apoptosis↗

PubMed2005

The cytotoxicity of naturally occurring styryl lactones.

We extracted and isolated three natural styryl lactones from Goniothalamus griffithii Hook f. Thoms and investigated their cytotoxicity on a panel of three hepatocyte cell lines, HepG2, drug resistant HepG2 (HepG2-R) and primary cultured normal mice hepatocyte in order to find candidates of potential anti-cancer drugs which have low toxicity on normal cells and high effect on tumors or drug resistant tumors. All the three styryl lactones showed evident cytotoxic activities on both HepG2 and HepG2-R cell lines; however, gonithalamin and goniodiol shows less toxicity on normal mice hepatocyte as the IC(50) values of them on normal mice hepatocyte were about three times of that on HepG2. Morphological observation and cell cycle analysis were employed to elucidate the mechanisms of cytotoxicity of the tested compounds. Many apoptotic cells were observed in gonithalamin- and altholactone-treated cells, whereas, cells with chromosomes gathered at the equator were easily found in goniodiol-treated cultures. The analysis of cell cycle showed that G(2)/M arrest contributed to goniothalimin- and gonidiol-caused cell death and apoptosis was the cause of gonithalamin- and altholactone-induced cell death. Our results suggest that the three styryl lactones may be prospectively developed into anti-tumor drugs, especially on treating drug-resistance tumor after structure modification.

Animals↗

PubMed2005

Impedance analysis of an electrode-separated piezoelectric sensor as a surface-monitoring technique for gelatin adsorption on quartz surface.

The early events pertaining to gelatin adsorption and desorption onto quartz surfaces were studied, employing an electrode-separated piezoelectric sensor (ESPS). The adsorption of gelatin on a quartz crystal surface corresponds to a mass increase, which can be monitored in real time by the changes in the impedance parameters of the ESPS. It was shown that the adsorption of gelatin on a quartz surface is partly irreversible with respect to the dilution of the bulk phase. The observed adsorption kinetics is compatible with a mechanism that involves adsorption, desorption, and transformation from a reversible adsorption state to irreversible one. A progressive approach method was established to simulate the adsorption process. The adsorption densities and kinetic parameters in the early adsorption process were obtained from the responses of the ESPS in the adsorption process. The influence of pH and ionic strength was tested. A comparison with the Langmuir adsorption model was made.

Adsorption↗

PubMed2004

Association of Vimentin overexpression and hepatocellular carcinoma metastasis.

The poor prognosis of hepatocellular carcinoma (HCC) has been associated with recurrence and metastasis. Recently, we established a pair of HCC cell lines from a primary (H2-P) and its matched metastatic (H2-M) HCC tumors. A high density of cDNA microarray with 9184 human cDNA was used to identify the differentially expressed genes between H2-P and H2-M. Comparing with H2-P, eight upregulated and six downregulated genes were detected in H2-M. One interesting finding is the overexpression of Vimentin (VIM), a well-defined intermediate filament, which has been linked to a more aggressive status in various tumors. The correlation of overexpression of VIM and HCC metastasis was studied by immunohistochemistry using a tissue microarray with 200 primary HCCs and 60 pairs of primary and matched metastatic HCC samples. Tissue microarray demonstrated that the overexpression of VIM was significantly associated with HCC metastasis (P<0.01). This finding strongly suggests that the overexpression of VIM may play an important role in the metastasis of HCC.

Adult↗

PubMed2003

[Polymorphism of insulin receptor substrate-1 gene in patients with coronary heart diseases].

OBJECTIVE: To explore the relationship between the polymorphism of insulin receptor substrate-1 (IRS-1) gene and coronary heart diseases in Chinese population. METHODS: A total of 113 patients with coronary heart diseases and 194 healthy Chengdu residents with less than 82 mmol/L of TG and 6.2 mmol/L of TC in fasting serum testing were selected and compared. The genotype and allele frequency of IRS-1 gene polymorphism was assayed by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). The serum lipids were measured by enzymatic kits. RESULTS: The GG genotype dominated in the IRS-1 gene with frequency of 0.960 and 0.985 for patients and healthy controls respectively. Difference appeared in R allele frequency (0.015 for healthy controls and 0.040 for patients, P = 0.05). Patients with genotype G/R had significantly higher level of serum TC and lower level of plasma glucose than patients with genotype G/G (P < 0.05). CONCLUSION: IRS-1 gene polymorphism is associated with coronary heart disease in Chinese population. The G/R and G/G genotype of IRS-1 gene contributes to the increasing of serum cholesterol and plasma glucose respectively.

Aged↗

PubMed2003

[An epidemiologic investigation of acute rheumatic fever and rheumatic heart disease among students aged 5-18 in west area of Sichuan Province].

OBJECTIVE: To study the incidence of acute rheumatic fever (ARF) and its epidemiologic features and the prevalence rate of rheumatic heart disease in west area of Sichuan province. METHODS: By using disease surveillance program, an epidemiologic investigation of ARF was performed from June 1992 to June 1995 and an annual screening survey was carried out among 46,595 students aged 5-18 in 1993 and 1994. RESULTS: The annual incidence of ARF was 12.87 per 10(5), there was no difference between the rural area and the urban area. ARF was found to be more frequent in students aged 9-15 years and in autumn and winter. All of the ARF patients had rheumatis and 83.3% of the cases were accompanied with heart lesion. The prevalence rate of rheumatic heart disease was 11 per thousand. CONCLUSION: The long-term monitoring of epidemiologic trend and community-based controls of rheumatic fever and rheumatic heart disease among students aged 5-18 are necessary and effective.

Adolescent↗

PubMed2003

[Impact of high-density lipoprotein on the apoptosis of endothelial cells induced by oxidized low-density lipoprotein].

OBJECTIVE: To investigate the impact of HDL on oxLDL-induced apoptosis of endothelial cells and relevant mechanisms. METHODS: Human umbilical venous endothelial cells (ECV-304) were exposed to oxLDL or oxLDL + HDL. The apoptosis of the endothelial cells was checked by the Flow cytometry and DNA electrophoresis, while caspase-3 activity was meaured simultaneously. RESULTS: The apoptosis rates induced by 100 microg/ml and 200 microg/ml of oxLDL were 28.40 + 5.30% and 34.7 +/- 4.64%, with caspase-3 activity of 166. 01 +/- 16.44 and 263.74 +/- 46.62 pmol/(min x mg pro), respectively. The DNA electrophoresis showed typical ladders. With exposure to HDL (200 mixrog/ml), the above apoptosis rates dropped to 8.06 +/- 2.35% and 9.40 +/- 2.58% respectively. There were no apoptotic ladders while the caspase-3 activities were significantly reduced (67.73 +/- 14.83 and 111.26 +/- 27.13 pmol/(min x mg pro). CONCLUSIONS: HDL can significantly reduce the apoptosis of cultured endothelial cells induced by oxLDL. This effect may be mediated via suppression of caspase-3 activity.

Apoptosis↗

PubMed2003

[Associations between aldosterone synthase gene polymorphisms and left ventricular structure and function in Chinese normal Han People].

OBJECTIVE: The aim of the present study was to investigate the association between a polymorphism of the aldosterone synthase gene CYP11B2 and left ventricular structure and function in Chinese Han people. METHODS: One handred and ten persons aged 20 to 49 years were studies by echocardiography to assess left ventricular size, mass and function. The subjects were genotyped with the use of PCR-RFLP. RESULTS: Three genotypes for aldosterone synthase at position -334 in the transcriptional regulatory region were found: TT, TC and CC. The distribution of sex and arterial blood pressure was homogeneous in the aldosterone synthase genotype groups. No significant associations of echocardiographic LV dimensions, mass and function with a specific aldosterone synthase genotype were noted. CONCLUSION: The above data are not in favor of a significant association between the polymorphisms of aldosterone synthase gene CYP11B2 and the LV structure and function in Chinese normal Han people.

Adult↗

PubMed2002

Impedance analysis of an electrode-separated piezoelectric sensor as a surface monitoring technique for surfactant adsorption on quartz surface.

This paper describes the measurement of the kinetics of adsorption of sodium dodecyl sulfate (SDS), an anionic surfactant, onto a quartz surface with a pre-adsorbed layer of Ca2+ as an ion bridge, using an electrode-separated piezoelectric sensor (ESPS). An impedance analysis method was employed to characterize the responses of the ESPS. The impedance and frequency parameters of the ESPS were examined as functions of the conductivity, permittivity, viscosity and density of the liquid. The adsorption process of SDS onto the quartz surface resulted in an increase in both the mass and energy dissipation of the oscillating quartz crystal. The adsorption densities could be estimated by the ESPS method after taking into consideration the effects of surface viscosity and roughness. The adsorption and desorption rate constants of SDS onto the quartz surface were calculated as ka = (88.1 +/- 0.26) mol(-1) L s(-1) and kd = (4.92 +/- 0.53) x 10(-3) s(-1), respectively, based on the Langmuir model. ESPS was shown to be a powerful means of examining anionic surfactant adsorption to the solid/liquid interface.

Journal Article↗

PubMed2002

[Expression of integrin alpha 6 in hepatic sinusoidal capillaration].

OBJECTIVE: To explore the expression of integrin alpha 6 in hepatic sinusoidal capillaration. METHODS: The rat hepatic fibrosis model was established by injection of carbon tetrachloride subcutaneously. Then the expression of laminin and integrin alpha 6 subunit was observed by immunohistochemistry and dot immuno-blotting. RESULTS: We observed sinusoidal capillaration formed by deposition of laminin along sinusoids in Disse interspace by immunohistochemistry staining. In normal rat the expression of integrin alpha 6 was restricted to portal vascular endothelial cells and bile duct epithelial cell membranes. No expression was observed in sinusoidal endothelial cell membranes. When capillaration integrin alpha 6 was detected in a continuous pattern along the sinusoids, the content of integrin alpha 6 was significantly higher in fibrotic liver tissues than in normal liver tissues as measured by dot immuno-blotting (P<0.05). CONCLUSIONS: During fibrogenesis, laminin continuously accumulate in liver tissues and form basement membrane resulting in sinusoidal capillaration, and then induce the expression of integrin alpha 6 on SEC membranes.

Animals↗

PubMed2002

[Effects of genistein on the fenestrae, proliferation and nitric oxide synthesis of liver sinusoidal endothelial cells from carbon tetrachloride-induced experimental hepatic fibrosis rats].

OBJECTIVE: To investigate the effects of genistein, a tyrosine protein kinase inhibitor, on the fenestrae, proliferation and nitric oxide (NO) synthesis of the liver sinusoidal endothelial cells from CCl(4)-induced hepatic fibrosis rats in vitro. METHODS: By in situ collagenase perfusion and two-step percoll gradient centrifugation, SECs were isolated and cultured from normal and CCl(4)-treated Wistar rats. The fenestrae of SECs were observed by the scanning electron microscopy, and the SECs cell proliferation was determined by the MTT assay. The concentrations of NO in the cultured medium of SECs were detected indirectly by measurement of nitrates and nitrites (the stable products of NO) using the nitrate reduction method. RESULTS: Scanning electron microscopic studies revealed that the number of fenestrae in SECs from all stage of hepatic fibrotic rats was decreased markedly as compared with the SECs from normal controls; however, no obvious changes in the fenestrae of SECs were observed after treated with genistein (100 mumol/L) for 24 hours. After treated with 100 mumol/L genistein for 24 hours, the cell proliferation rates of SECs from all stages of hepatic fibrosis were decreased significantly was compared with the control group (P<0.05). The synthesis of NO by SECs from all stages of hepatic fibrosis was markedly lower than those of normal controls. Treatment with 100 mumol/L genistein for 24 hours could increase the synthesis of NO by SECs from the early stage (stage I) of fibrosis; however, this effect of genistein was not observed in SECs from stage II or III of fibrosis at this concentration. CONCLUSIONS: The results suggest that genistein may play an important role in regulating the function of SECs.

Animals↗

PubMed2002

[The paraoxonase Gln-Arg 192 polymorphism in patients with endogenous hypertriglyceridemia in Chinese population].

OBJECTIVE: To investigate the 192 Gln-Arg polymorphism of paraoxonase (PON) gene and its relationship with serum lipids and apolipoproteins (apo) levels in patients with endogenous hypertriglyceridemia in Chinese population in Chengdu area. METHODS: The genotype and allele frequencies of paraoxonase gene 192 Gln-Arg polymorphism were assayed by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). Serum lipids were measured by enzymatic kits and apolipoproteins AI, A II, B100, C I, C II and E were measured by the RID kits developed by the Apolipoprotein Research Unit of this university in 128 HTG patients whose fasting serum TG levels were > or = 2.26 mmol/L and 129 healthy subjects whose fasting serum TG levels were < 1.82 mmol/L and TC levels < 6.2 mmol/L from a population of Chinese Han nationality in Chengdu area. RESULTS: Both in HTG group and control group, the QR genotype of PON gene was the major one, and the frequencies were 0.515 and 0.581 respectively. No differences were found in PON gene Gln-Arg polymorphism between the HTG group and the control group. In the control group, the QQ genotype of PON gene was found to have higher serum apoA I levels, compared with the RR genotype (P < 0.05). But in the HTG group, when compared with the RR genotype, the QQ genotype was found to have lower serum apoA I and A II levels and higher serum apoE levels. CONCLUSION: These may be an association of the QQ genotype of the paraoxonase 192 Gln-Arg polymorphism with the decrease of serum apoA I level and the increase of serum apoE level in endogenous hypertriglyceridemica.

Aged↗

PubMed2002

[Study on the expression of adhesion molecule related proteins in patients with coronary heart disease].

OBJECTIVE: To assess the expression level of adhesion molecule related proteins CD11a and CD11b on neutrophils, monocytes and lymphocytes in patients with coronary heart disease and detect the relation of expression level to the degree of stenosis of coronary arteries and the severity of coronary heart disease. METHODS: The subjects were divided into three groups: stable angina, unstable angina, and healthy people as control. The amount of cell adhesion molecule related proteins CD11a and CD11b on neutrophilic granulocytes, monocytes and lymphocytes of peripheral blood was measured in three groups by using fluorescent immunoassay method on flow cytometer. Relationship between them was analysed. RESULTS: No significant difference in the expression of CD11a between the angina and control groups was observed. The expression of CD11b on lymphocytes and neutrophilic granulocytes in the unstable angina group and stable angina group was significantly higher than that in the healthy people(P < 0.01 and P < 0.05). Although the amount of CD11b measured in the group of severe coronary artery stenosis was higher than that measured in the mild light group, the difference was not significant (P > 0.05). CONCLUSION: The amount of adhesion molecule related protein CD11b on neutrophilic granulocytes and lymphocytes in patients with unstable angina is higher than that in patients with stable angina and control group, but there is no relationship between the expression level of CD11b and the degree of coronary stenosis.

Adult↗