Biomedical subjects

D Liu

Publications and source records attributed to D Liu.

At least 163 records · Page 9Linked to original sources

PubMed2001

[Mannose-binding protein gene polymorphism influences the patterns of glomerular immune deposition in IgA nephropathy].

OBJECTIVE: To investigate the relationship between mannose-binding protein(MBP) gene codon 54 (GGC/GAC) polymorphism and the patterns of glomerular immune deposition in IgA nephropathy (IgAN) and explore its functional significance. METHODS: IgAN patients were divided into two groups according to the pattern of glomerular immune deposition. Group A included 77 patients with glomerular IgA and C3 deposits. Group AGM consisted of 70 patients with glomerular IgA, IgG, IgM, C3 and Clq deposits. One hundred and forty healthy adults were used as normal controls. MBP genotypes were investigated by PCR-RFLP. Serum MBP levels of some subjects with different genotypes were also assayed by ELISA simultaneously. RESULTS: The genotype frequency of GAC heterozygotes was significantly higher in group AGM than in group A (41.4% vs. 19.5%, P<0.01) or normal subjects (41.4% vs. 26.4%, P<0.05), while no difference was found in the distribution of MBP genotypes between group A and normal subjects. The allele frequency of GAC mutation was also higher in group AGM than in group A (0.236 vs. 0.136, P<0.05) or normal subjects (0.236 vs. 0.146, P<0.05). The variant allele (GAC) was markedly associated with group AGM (OR=1.95, 95%CI: 1.06-3.58). In both group A and group AGM, more patients carrying the variant allele had episodes of upper respiratory or gastrointestinal infections prior to the onset or exacerbation of IgAN than wild homozygotes. In addition, a significant difference in serum MBP level was also observed among the three genotypes (GGC/GGC>GGC/GAC>GAC/GAC) (P<0.0001) for all groups, while there were no differences in serum MBP levels for subjects with the same genotypes among the three groups (P>0.05). CONCLUSION: The above findings provide evidence that IgAN patients with abundant immune deposits in glomeruli show a higher frequency of MBP gene variation which is associated with a high frequency of infection and a low serum MBP level. This genetic deficiency may lead to an impaired first-line defense and a less effective clearance of immune complex than those without this mutation and thereafter accelerate glomerular immune deposition during the process of disease.

Adolescent↗

PubMed2001

Hydrodynamics-based gene delivery.

The need for a safe and efficient method for gene delivery has stimulated the recent emergence of vectorless methods (e.g., naked DNA) as promising alternatives to the available viral- and non-viral-based systems. Among these methods, hydrodynamics-based gene delivery through systemic injection of DNA offers a convenient, efficient and powerful means for high-level gene expression in mice. This review deals with the background and progress made so far with this new gene delivery method, the potential mechanism underlying the hydrodynamics-based DNA transfer into cells and its potential applications towards gene function analysis, protein expression and gene therapy in whole animals.

Animals↗

PubMed2001

[Correlation between liver fibrosis stage and serum liver fibrosis markers in patients with chronic hepatitis B].

OBJECTIVE: To evaluate the diagnostic value of serum liver fibrosis markers by analyzing the correlation between liver fibrosis stage in patients with chronic hepatitis B and serum liver fibrosis markers, such as hyaluronate, type III procollagen, laminin, and type IV collagen. METHODS: There were 278 patients with chronic hepatitis B in this series. Before liver biopsy, the serum was collected to test hyaluronate, type III procollagen, laminin, and type IV collagen. Data were analyzed statistically. RESULTS: Liver fibrosis stage was correlated to inflammation degree. In patients with moderate or serious liver inflammation and fibrosis, serum hyaluronate was above normal level, and correlated to liver inflammation and fibrosis. For patients with chronic hepatitis B, serum type III procollagen, laminin, and type IV collagen increased apparently. While laminin was correlated to liver fibrosis, type III procollagen and type IV collagen correlated to liver inflammation. CONCLUSIONS: Serum hyaluronate, type III procollagen, laminin, and type IV collagen could reflect the state of liver fibrosis. Hyaluronate may be a useful marker for liver cirrhosis.

Adolescent↗

PubMed2001

[Pests on zingiberaceous plants and their control in south China].

The pests on the zingiberaceous plants and their occurrence and damage as well as control have been investigated in the ginger plantation of South China Botanical Garden recently. 12 insect pests and 1 mite pest are common. To control them effectively, such as selecting loose, fertile soil as planting field with proper shade, applying healthy and vigorous seeds, seedling and rhizomes for propagation, regulating plant density, sanitizing the field in time are mostly recommended. The application of chemical and biological pesticides and the protection on the beneficial organisms are also stressed.

China↗

PubMed2001

[An inquiry into the relationship among pathology, clinic and laboratory indexes of the severe viral hepatitis].

OBJECTIVE: This study was to analyze the relationship among pathology, clinic and laboratory indexes in 62 cases of the acute severe hepatitis (ASH) and 72 cases of the subacute severe hepatitis(SSH) to offer a correct diagnosis and recognition of the disease. METHODS: A total of 134 severe hepatitis cases with confirmed pathology treated in a course of 24 years were analyzed by programs of EXCEL 2000. RESULTS: When compared ASH with SSH, the onset of the age were 40 +/- 13 years old and 44 +/- 15 years old, P < 0.05, the rates of hepatitis coma were 100% and 66.7% respectively. The liver weight of all the cases decreased. The tests of TBiL, PTA, Cho, NH3 and WBC between ASH and SSH had significant differences. CONCLUSION: Hepatic encephalopathy is a necessary criterion for ASH. The TBiL, PTA and Cho changes are closely related with severe viral hepatitis, they not only are the essential laboratory indexes but also the indispensable factors for disease development and prognosis of severe viral hepatitis.

Acute Disease↗

PubMed2001

[Effects of the alterations of membrane shear elastic modulus and viscosity on the deformation and orientation of RBCs].

Neuraminidase can partly remove the surface charge of RBCs through a biochemical interaction; thus it can give rise to alterations in the microstructure of membrane, the shear elastic modulus (E) and the viscosity(micron) of membrane. Changing the time of treatment and the dose of neuraminidase and using a new ektacytometry that can separate deformation index DI into orientation index (DI)or and small deformation index (DI)d for RBCs in shear flow field of low viscosity, we measured (DI)d and the half time t0.5 when the DI recovered to half of the maximum in the process of relaxation for every treated sample. (DI)d and t0.5 were put respectively into the RBC membrane shear elastic modulus formula and the membrane viscosity formula which were put forward by Wen Zong-yao and Yan Zong-yi et al[1]. The rules of the alterations of E and micron were obtained. We also measured DI and (DI)or. It was found that E and micron increased greatly but DI and (DI)or decreased when the dose of neuraminidase and the time of treatment were increased. There was a contrary correlation between them. These data demonstrated that the increase of E and micron weakened the deformability and the ability of orientation of RBCs.

Animals↗

PubMed2001

Clinical significance of cyclin B1 protein expression in squamous cell carcinoma of the tongue.

PURPOSE: Cyclin B1 plays an important role in control of the G(2)-M transition of the cell cycle. We have shown recently that overexpression of cyclin B1 is associated with poor outcome in patients with early stage squamous cell carcinoma (SCC) of the lung. EXPERIMENTAL DESIGN: To determine the role of cyclin B1 in SCC of the tongue, we analyzed tumor specimens from 41 patients with stage II-IV SCC of the tongue who underwent curative surgery using immunohistochemistry. RESULTS: The median follow-up of all patients was 83 months. Overexpression of cyclin B1 was observed in 15 (37%) of the 41 tumors, a similar frequency to that found in SCC of the lung. Patients whose tumors showed overexpression of cyclin B1 had a poor event-free survival compared with those lacking this feature (P = 0.04 by Log-rank test). Multivariate analysis of traditional clinical/pathological factors showed that cyclin B1 overexpression was an independent prognostic indicator. CONCLUSIONS: Our study indicates that cyclin B1 is overexpressed in a subset of SCC of the tongue and is associated with a more aggressive biological behavior of the disease.

Carcinoma, Squamous Cell↗

PubMed2001

Cyclin D1 and p16 alterations in advanced premalignant lesions of the upper aerodigestive tract: role in response to chemoprevention and cancer development.

PURPOSE: To better understand the role of G(1)-S transition regulator abnormalities in the pathogenesis of advanced premalignant lesions of the upper aerodigestive tract and the biological effects of chemoprevention, we studied biopsies obtained sequentially from participants in a prospective trial using 13-cis retinoic acid, IFN-alpha, and alpha-tocopherol for 12 months. EXPERIMENTAL DESIGN: Cyclin D1 and p16 expression were analyzed by immunohistochemistry, loss of heterozygosity by polymerase chain reacting amplification, and then electrophoretic separation of the products, methylation of the p16 promoter by methylation-specific polymerase chain reacting, and cyclin D1 gene amplification by fluorescence in situ hybridization. RESULTS: Baseline dysregulation of cyclin D1 expression was found in 50% (14 of 28) and was reversed in 6 of 14 cases, whereas p16 expression was lost in 46% (13 of 28) and regained in 2 of 13 cases. Loss of heterozygosity at 9p21 occurred in 68% and p16(INK4a) promoter methylation occurred in 75% of cases, with increasing frequency from mild to severe dysplasia. Cyclin D1 gene amplification was identified in two cases. Cyclin D1 protein dysregulation at last follow-up alone and in combination with p16 loss was associated with histological progression and cancer development (P < 0.01). CONCLUSIONS: Additional study of these alterations in a larger sample and exploration of the upstream signaling partners of these cell cycle regulators in vivo is warranted to identify cancer risk profiles that would be meaningful targets for chemopreventive intervention.

Adult↗

PubMed2001

Glucose transporter in human glomerular mesangial cells modulated by transforming growth factor-beta and rhein.

AIM: To identify GLUT1 in human mesangial cells and its regulation by TGF-beta1 and rhein. METHODS: Identification of GLUT1 was performed in human mesangial cells by analyzing its mRNA expression, protein product, and functional assay. The effects of TGF-beta1 and rhein on glucose uptake and GLUT1 mRNA expression in mesangial cells were examined by [3H]-2-deoxy-D-glucose uptake and Northern blotting analysis. RESULTS: It was found that human mesangial cells do express functional GLUT1. The 2-DOG uptake of mesangial cells was markedly increased by TGF-beta1 stimulation with simultaneous elevated expression of GLUT1 mRNA. Increased glucose uptake and GLUT1 mRNA expression in mesangial cells induced by TGF-beta1 were markedly attenuated by rhein in a dose-dependent manner. CONCLUSION: We found that functional GLUT1 did present in human mesangial cells. TGF-beta1 stimulated the glucose uptake in mesangial cells through upregulation of GLUT1 expression, this effect of TGF-beta1 could be antagonized by rhein.

Anthraquinones↗

PubMed2001

Rhein inhibits renal tubular epithelial cell hypertrophy and extracellular matrix accumulation induced by transforming growth factor beta1.

AIM: To investigate the effects of rhein on cell hypertrophy and accumulation of extracellular matrix (ECM) in the renal tubular epithelial cells. METHODS: LLC-PK1 cells were incubated with transforming growth factor beta1 (TGFbeta1) 2 microg/L for 24 h to induce cell hypertrophy and production of ECM. To evaluate the effects of rhein on inhibiting the action of TGFbeta1, cell volume, cellular protein level, and [3H]leucine incorporation in LLC-PK1 cells treated with rhein at different concentrations were measured. In addition, the [3H]proline incorporation, level of fibronectin (FN) in supernatant, and mRNA expression of collagen IV and FN were also detected in rhein treated cells. RESULTS: The cell volume, cellular protein content, and [3H]leucine incorporation were markedly increased in LLC-PK1 cells after TGFbeta1 stimulation as compared with control (P < 0.01), and this TGFbeta1-stimulated cell hypertrophy was ameliorated by rhein. It was observed that TGFbeta1 not only increased the production of FN and [3H]proline incorporation in LLC-PK1 cells (P < 0.01), but also enhanced the mRNA expression of collagen IV and FN. Rhein significantly decreased the protein production and mRNA expression of ECM in LLC-PK1 cells stimulated by TGFbeta1. CONCLUSION: Rhein can inhibit cell hypertrophy and ECM accumulation in LLC-PK1 cells induced by TGFbeta1, which may partly account for the role of rhein in preventing and retarding the progression of diabetic nephropathy.

Animals↗

PubMed2001

Triptolide inhibits vascular endothelial growth factor expression and production in endothelial cells.

AIM: To investigate the effects of triptolide on vascular endothelial growth factor (VEGF) expression and secretion by endothelial cells, and explore the mechanism of anti-proteinuric effect of triptolide on glomerulonephritis. METHODS: A human umbilical endothelium derived cell line (ECV-304) from American Type Culture Collection (ATCC) was used in this study. The effects of triptolide on VEGF mRNA expression, production, and secretion induced by 12-o-tetradecanoyl-phorbol-13-acetate (TPA) were measured by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), flow cytometry, and enzyme linked immunosorbent assay (ELISA) respectively. The endothelial c-fos/c-jun mRNA expression were also detected by RT-PCR after treatment of triptolide. RESULTS: VEGF mRNA expression was markedly up-regulated by TPA-stimulation. In addition, the production and secretion of VEGF in endothelial cells also increased in TPA treated cells. It was founded that triptolide inhibited VEGF mRNA expression, protein production and secretion in endothelial cells induced by TPA. Interestingly, TPA-induced c-fos/c-jun mRNA expression in endothelial cells was also inhibited by triptolide. CONCLUSION: Triptolide is a potent inhibitor of VEGF expression and production in endothelial cells. The inhibitory effects of triptolide on VEGF expression and production can contribute to its anti-proteinuric effect on glomerulonephritis. Down-regulation of c-fos/c-jun expression in endothelial cells by triptolide is one of the mechanisms of the inhibitory effect of triptolide on VEGF expression.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2001

[Influence of rare earth elements on chemical transformation of nitrogen in agricultural soil].

Soil available N, NH4(+)-N and NO3(-)-N contents and soil urease activity were measured after application of rave earth elements(REEs). The results showed that the contents of soil available N and NH4(+)-N were affected by application of REEs, being significantly differed from those in the control when the dosage was higher than 5 mg.kg-1 dry soil. However, soil NO3(-)-N content in treated plots did not differed from that in the control. No observed effect concentration (NOEC) for the potential influence of REEs on the chemical transformation and availability of soil available nitrogen was found to be 5 mg.kg-1 dry soil. The decrease of soil available N concentration was found closely correlated to the inhibition of soil urease activity (R2 = 0.87). It was suggested that the inhibition effect of REEs on the enzymatic nitrogen mineralization should be one of the major causes for the decline of soil available nitrogen concentration. The decrease of available nitrogen concentration occurred shortly after REEs application, indicating that there should be a self-regulation process to maintain the available nitrogen concentration in soil.

Agriculture↗

PubMed2001

[Physiology and development of two Roegneria kamoji populations stressed by copper].

Roegneria kamoji grown copper tailings had weak stem, short height, and thick leave color, while its counterpart on normal soil was the opposite. Exposed to copper, R. kamoji had a decreased chlorophyll content. A certain concentration of copper could promote the seed germination of R. kamoji, and the extract of copper tailings did not decrease the seed germination rate, but deferred the germination. Root growth test indicated that when the concentration of copper was 0.125 mg.L-1, the rooting of R. kamoji was promoted. If the concentration was more than 0.25 mg.L-1, the rooting was inhibited significantly. R. kamoji colonized on normal soil wase more sensitive to copper than that on Cu-polluted soil.

Chlorophyll↗

PubMed2001

[Brief history of cosmetology in the imperial palace of China].

The development of Chinese Palace's cosmetology is divided into three periods. It is in its embryonic stage that from the Xia to the Western Jin. The drugs and perfumes related to cosmetology were taken seriously by the Palace. The formulation of facial beauty was established. From the Eastern Jin to the end of Tang Dynasty was the forming periods. Cosmetology has been fully developed, and became the physical civilization which could enjoy by both nobels and common people. The developing and enriching time was from the Wu Dai to the end of the Qing Dynasty. The theory of cosmetology achieved a great development. The number of prescriptions of the Palace's cosmetology were increased greatly.

China↗

PubMed2001

Identification and function of glucose transporter 1 in human mesangial cells.

OBJECTIVE: To evaluate the role of glucose transporter 1 (GLUT1) in the glucose uptake of glomerular mesangial cells. METHODS: Cultured human glomerular mesangial cells were used. The expressions of glucose transporter 1 mRNA and protein were detected with reverse transcription-polymerase chain reaction (RT-PCR), flow cytometry and immunofluorescence staining. Glucose uptake was determined with 2-deoxy-[3H]-D-glucose uptake assay. RESULTS: The expressions of GLUT1 mRNA and proteins were detected in human mesangial cells. Glucose uptake and its kinetics assay showed that GLUT1 is a functional glucose transporter in cultured human mesangial cells, and that its function could be inhibited by the specific inhibitor, Phloretin. CONCLUSION: GLUT1 is the predominant glucose transporter in human mesangial cells, which has the kinetic characteristics of high affinity and low capacity for D-glucose. This suggests that in order for mesangial cells to take up excessive quantities of glucose, as in diabetes, changes in glucose transporter expression, translocation or activity may be required.

Glomerular Mesangium↗

PubMed2001

Histochemical study of transmyocardial laser channels in dogs.

OBJECTIVE: Laser-induced myocardial injury was investigated in a canine transmyocardial laser revascularization model. METHODS: A total of 23 channels were created in the left ventricles of 5 animals with a CO2 laser. Four animals were sacrificed immediately and one at week 2. Lactate dehydrogenase and succinate dehydrogenase in channel regions were examined with a Nitro-BT method staining. RESULTS: Immediately after the procedure, laser channels and surrounding injured myocardium could be stratified from the center to the border into 5 concentric zones, i.e., vaporized zone, carbonized zone, enzyme-disappeared zone, enzyme-decreased zone and enzyme-concentrated zone. Two weeks later, the phenomenon disappeared. CONCLUSIONS: Immediately after transmyocardial revascularization, there is a ring of enzyme-concentrated zone at the outermost region of injured myocardium. Two weeks later, enzyme activities of reversibly injured myocytes appear to have recovered.

Animals↗

PubMed2001

[Expression of monocyte chemotacticp protein-1 in the eutopic endometrium of women with endometriosis].

OBJECTIVE: To examine the expression of monocyte chemotactic protein-1 (MCP-1) messenger ribonucleic acid (mRNA) in the endometrium of patients with and without endometriosis. METHODS: A reverse transcription-polymerase chain reaction (RT-PCR) method was utilized to examine and quantitate MCP-1 mRNA expressions and levels in the eutopic endometrium. Thirty patients with endometriosis were included as study group, and 20 patients without endometriosis selected as control group. RESULTS: 26 (87%) of 30 samples of endometrium from patients with endometriosis expressed MCP-1 mRNA, 19 of which were strong expression, while 15 (75%) of 20 samples of endometrium from patients without endometriosis express MCP-1 mRNA (P > 0.05). When endometriosis were grouped by Revised American Fertility Society (RAFS) stages, there was no obvious correlation between stage and MCP-1 mRNA expression level (P > 0.05). Semi-quantitative PCR showed the expression level of MCP-1 in endometrium of patients with endometriosis were higher than those of patients without endometriosis (0.746 +/- 0.345 Vs 0.460 +/- 0.341 respectively, P < 0.05). CONCLUSIONS: The MCP-1 mRNA is over expressed in the eutopic endometrium from patients with endometriosis, which may play some roles on the pathogenesis of endometriosis.

Adult↗

PubMed2001

[Effect of Cu and As and their combination pollution on Glycine max].

Experiments are carried out with hoagland cultivation to study the effects of Cu and As and their interactions on the germination and seedling growth of Glycine max. The results show that Cu or As pollution reduced proteinase activities, inhibited the seedling growth and the respiration rate of germinating seed of soybean. The inhibition increased as Cu and As concentration increased, POD activities increased with increasing Cu and As concentration. Cu pollution has an antagonistic effect against the pollution of As, and vise versa.

Arsenic↗