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Liang Liu

Publications and source records attributed to Liang Liu.

At least 73 records · Page 4Linked to original sources
PubMed2005

[Application of virtual reality technique in forensic pathology].

This article reviewed general information, application and progress of the virtual reality (VR) technique. Lectures showed that the VR technique would impact and prompt the teaching, experiment, research and application of forensic pathology with the development of operation guiding system, virtual autopsy, micro-imaging technique. Because of the limitation of software, hardware and the expense, the VR technique needed to be improved and perfected.

Autopsy↗
PubMed2005

[Influence of macrophages on the expression of vascular endothelial growth factor receptor mRNA, homeobox B2 mRNA, and integrin alpha nu beta3 in vascular endothelial strain].

OBJECTIVE: To investigate the influence of macrophages on the expression of the vascular endothelial growth factor (VEGF) receptor (KDR) mRNA, homeobox B2 (HOXB2) mRNA, and integrin alpha nu beta3 in vitro in vascular endothelial strain. METHODS: Human umbilical vein cells (ECV304) were cultured in vitro and divided into 4 groups, i.e. (1) ECV304 group, (2) ECV304 + conA group [with conA (25 microg/ml in culture) added to ECV304], (3) ECV304 + U937 group (with 1 x 10(5)/ml of U937 cells added to 1 x 10(5)/ml ECV 304), (4) ECV304 + U937 + conA group [with 1 x 10(5)/ml of U937 cells and conA (25 microg/ml in culture)] groups. Forty-eight hours after culturing, the expression of integrin receptor alpha nu beta3 and the changes in the expression of KDR mRNA and HOXB2 mRNA in each group were determined by immunofluorescent technique and RT-PCR, respectively. RESULTS: The expression of integrin receptor alpha nu beta3, KDR mRNA, and HOXB2 mRNA in ECV304 group were 6.7 +/- 1.5, 0.633 +/- 0.012, and 0.674 +/- 0.004, respectively, while those in ECV304 + U937 + conA group (10.2 +/- 1.7, 0.879 +/- 0.003, 0.947 +/- 0.003) were obviously more upregulated when compared with those in ECV304 group (P < 0.01). No difference in the above indices was found between ECV304 and ECV304 + conA, ECV304 + U937 groups (P > 0.05). CONCLUSION: Macrophages activated by ConA can accelerate the proliferation, migration and adhesion to the basement membrane matrix of vascular endothelial cells through the influence on the expression of KDR mRNA, HOXB2 mRNA and integrin alpha nu beta3, and through this pathway the angiogenesis is modulated.

Cells, Cultured↗
PubMed2005

[The effects of triptolide inhibition of mouse lymphocytes activated in vitro].

OBJECTIVE: To study the effects of triptolidel on murine T lymphocytes activated. METHODS: We isolated and cultured the mouse lymphocytes from lymph nodes of mice in vitro. The lymphocytes were pre-treated triptolide for 1 h prior to activation with ConA. After 6 hours stimulation, determined IL-2 and IFN mRNA expression by RT-PCR. CD69 expression of mouse CD3+ T cell was determined by multi-color flow cytometric analysis after 6 hours stimulation, and CD25 expression of mouse CD3+ T cell was determined by multi-color flow cytometric analysis after 24 hours stimulation. RESULTS: TRD could inhibit IL-2 and IFN-gamma mRNA expression. It also inhibited CD69 and CD25 expression of mouse CD3+ T cell. CONCLUSION: the immunosuppressive mechanism of TRD may be related to the inhibitory effects on IL-2 and IFN-gamma mRNA expression and the inhibition of CD69 and CD25 expression.

Animals↗
PubMed2005

[The effects of resveratrol on the activation, proliferation and cytokine expression of murine T lymphocytes].

AIM: To study the effects of resveratrol (RSV) on the activation, proliferation and cytokine expression of murine T lymphocytes. METHODS: Murine T lymphocytes were isolated from lymph nodes and cultured in vitro. The lymphocytes were pre-treated with RSV for 1 h prior to activation with PDB plus ionomycin. (3)H-TdR incorporation was used to detect T cell proliferation. IL-2 and IFN-gamma mRNA were detected by RT-PCR, IL-2 and IFN-gamma proteins were detected by intracellular cytokine staining with flow cytometry. RESULTS: RSV can inhibit the proliferation and expression of IL-2 and IFN-gamma of T lymphocytes. CONCLUSION: The immunosuppressive action of RSV may be related with its inhibitory effects on T cell activation, proliferation and cytokine expression.

Animals↗
PubMed2004

Genetic and epigenetic modulation of telomerase activity in development and disease.

Telomerase activity is one of the most important factors that have been linked to multiple developmental processes, including cell proliferation, differentiation, aging and senescence. Dysregulation of telomerase has often been found in developmental abnormalities, such as cancer, loss of function in the hematopoietic system, and low success rate of somatic cloning. A comprehensive network of transcription factors has been shown to be involved in the genetic control of telomerase expression and activity. Epigenetic mechanisms have recently been shown to provide an additional level of regulation, and may be responsible for the diverse expression status of telomerase that is manifested in a tissue and cell-type-dependent manner. This article summarizes the recent developments in the field of telomerase research with a focus on the coregulation of the telomerase gene by both genetic and epigenetic pathways. Developmental consequences of aberrant telomerase activity will also be summarized and discussed.

Aging↗
PubMed2004

Epigenetic regulation of human telomerase reverse transcriptase promoter activity during cellular differentiation.

The human telomerase reverse transcriptase (TERT) gene is transcriptionally inactivated in most differentiated cells but is reactivated in the majority of cancer cells. To elucidate how TERT is inactivated during differentiation, we applied all-trans retinoic acid (ATRA) to induce the differentiation of human teratocarcinoma (HT) cells and human acute myeloid leukemia (HL60) cells. We first showed that TERT promoter activity decreased rapidly, which preceded a gradual loss of endogenous telomerase activity following ATRA induction. To elucidate the underlying mechanisms of the reduced TERT promoter activity during differentiation, we performed epigenetic studies on the TERT promoter and found a progressive histone hypoacetylation coupled with a gradual accumulation of methylated cytosines in the TERT promoter. We also observed that the TERT promoter was less methylated in pluripotent HT cells than in multipotent HL60 cells throughout a 12-day differentiation process. This origin-dependent epigenetic change was also confirmed in histone acetylation studies, indicating that the TERT promoter was more resistant to deacetylation in HT cells than in HL60 cells. Taken together, our results demonstrate synergistic involvement of DNA methylation and histone deacetylation in the down-regulation of TERT promoter activity that may be dependent on the origin of the cell types, and they add new insight into the way telomerase activity may be regulated during differentiation.

Acetylation↗
PubMed2004

Long-time fulvic acid supplementation modulates hydroxylysyl glycosylation of collagen in mice.

In order to investigate the impact of fulvic acid (FA) on the hydroxylysyl glycosylation in collagen bio-synthesis, 40 NMRI mice were divided into two groups (n = 20 in each group, consisting 10 females and 10 males). The animal was maintained for two generations by different diets: control group with normal water and food and study group with water containing 30 mg/L FA and normal food. The second generation of the animal was slaughtered, and the biochemical parameters of collagen content and the degree of collagen hydroxylysyl glycosylation in skin, rib and tibia were detected by biochemical methods. The mean value of collagen in the study group was increased slightly, and no significant difference between study group and control group was found (P > 0.05), but the content of glucose-glactose-hydroxylysine (GGH) was significantly decreased in the study group in comparison with the control group (P<0.01). It was suggested that through the decrease of GGH 30 mg/L FA could inhibit the activity of galactosyl-hydroxylysylglucosyl-transferase and further disturb the post-translational modification of collagen intracellularly.

Animals↗
PubMed2004

Profiling DNA methylation by bisulfite genomic sequencing: problems and solutions.

The surge of interest in DNA methylation during the last two decades has triggered an urgent need for an effective method to detect the methylation status of the cytosines in the genome. Bisulfite genomic sequencing is the most attractive choice so far for many laboratories. Various protocols have been established, but difficulties are often encountered, particularly by individuals who have limited experience in this field. This analysis presents a simple protocol that has consistently worked well in our laboratory. Discussions of potential technical problems and corresponding solutions are also included to facilitate the reproducibility of this protocol.

Chemical Precipitation↗
PubMed2004

Specific inhibiting effects of Ilexonin A on von Willebrand factor-dependent platelet aggregation under high shear rate.

BACKGROUND: Ilexonin A (IA), purified from the Chinese herbal medicine Maodongqing (Ilex pubescens Hook, et Arn) has been commonly used in south China to treat thrombotic disorders. In this study, we aimed to study the inhibiting effects and mechanism of IA on von Willebrand factor (vWF)-dependent high shear-induced platelet aggregation. METHODS: vWF-dependent high shear (10,800 s(-1)) induced aggregation of platelets obtained from normal donors in the presence or absence of IA was measured by a modified cone-plate viscometer and shear-induced vWF binding was measured by quantitative flow cytometry with monoclonal antibody known to bind exclusively to the C-terminal domain of vWF (LJ-C3) directly labeled with fluorescein isothiocyanate (FITC). P-selectin surface expression was also measured by a similar method with FITC conjugated anti-P-selectin monoclonal antibody (WGA1). RESULTS: Shear-induced platelet aggregation was inhibited by IA in a dose-dependent manner. The extent of aggregation decreased from (78.6 +/- 4.6)% in the absence of IA to (36.5 +/- 2.1)% in the presence of IA (3.3 mmol/L) (P < 0.0001, n = 9) with a high shear rate of 10800 s(-1). vWF binding and P-selectin expression were also inhibited by IA in a dose dependent manner. The number of binding FITC-LJ-C3 molecules increased after exposure of platelet-rich plasma to a high shear rate of 10800 s(-1) for 6 minutes, but this shear-induced increased binding platelet surface vWF molecules and P-selectin expression can be decreased in the presence of IA. CONCLUSION: vWF binding and vWF mediated platelet activation, aggregation occurring under high shear rate were inhibited by IA. IA may be a unique antithrombotic drug inhibiting the vWF-GP Ibalpha interaction, and may thus facilitate drug design targeting arterial thrombosis.

Fibrinolytic Agents↗
PubMed2004

[Arrhythmogenic right ventricular cardiomyopathy].

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a heart muscle disease of unknown etiology characterized by fatty or fibrofatty infiltration of the right ventricular myocardium. It is well known that ARVC is one of the important causes of sudden death in young individuals. The significant pathological change of ARVC is atrophy and fibrofatty myocardial replacement of the right ventricular free wall. According to the histopathological substrate ARVC could be divided into 2 types: fatty and fibrofatty myocardial replacement. Possible etiology including: (1) apoptosis or programmed cell death; (2) inflammatory; (3) myocardium dysplasia and (4) myocyte transdifferentiation theory.

Adipose Tissue↗
PubMed2004

[The study of status and advances on tetramine poisoning].

Tetramethylenedisulphotetramine(TETS) is virulent rodenticides which was strictly forbidden to use in China. Poison dose of TETS is very little, LD50 in rats in 0.1 mg/kg. Manifestations and signs of TETS poisoning are showed in 5 min. The long dated effect of poisoning is extremely strict. Mamy studys on TETS are restricted on the treatment of TETS poisoning, while that of poisoning mechanism is very few. This paper reviewed TETS poisoning mechanism, pathological changes and research advances.

Brain↗
PubMed2004

[Effects of total alkaloids of Tongbiling prescription on Th1 type cytokine expression in T lymphocytes].

AIM: To study the effects of total alkaloid of Tongbiling prescription(TBL) on Th1 type cytokine expression in T cells in order to elucidate the anti-inflammatory mechanism of TBL. METHODS: The lymphocytes were isolated from mouse mesenteric lymph nodes and cultured in-vitro. Various concentrations of TBL were added to the culture followed by phorbol ester and inomycin treatment and then incubated for another 4 hours. The expressions of IFN-gamma and TNF-alpha in the lymphocytes were analyzed by flow cytometry. RESULTS: 200 mg/L and 100 mg/L TBL could obviously inhibit IFN-gamma and TNF-alpha expressions in T lymphocytes. CONCLUSION: Inhibiting Th1 cytokine expression may be one mechanism by which TBL can treat rheumatoid arthritis.

Alkaloids↗
PubMed2004

Telomerase inhibition by retinoids precedes cytodifferentiation of leukemia cells and may contribute to terminal differentiation.

Human promyelocytic leukemia HL60 cells display high telomerase activity, a phenotype related to their immortal status. All-trans retinoic acid (ATRA) is a clinically effective cytodifferentiating agent. To understand the mechanism underlying ATRA-induced cytodifferentiation, we did a kinetic analysis of the role of ATRA in inhibiting telomerase in HL60 cells. Our studies indicate that telomerase inhibition by ATRA occurred relatively early after treatment of HL60 cells due to a rapid decrease in hTERT gene expression. More importantly, however, we found through monitoring the expression of CD11b, a marker for granulocytic differentiation of HL60 cells, that down-regulation of telomerase preceded the differentiation of HL60 cells. These observations suggest that the hTERT gene may be a primary target of ATRA regulation of cellular differentiation and the antileukemia activity of ATRA may be mediated by its ability to induce the differentiation of the promyelocytic leukemia cells through down-regulation of the hTERT gene.

CD11b Antigen↗
PubMed2004

[Effect of lipopolysacharide on the biological features and growth factor secretion power of U937 cell line].

OBJECTIVE: To investigate the effect of lipopolysacharide (LPS) in different concentrations on the biological features and growth factor secretion power of U937 cell line. METHODS: In vitro cultured U937 cells were stimulated by 0 (as control), 0.1, 1.0, 10.0, 50.0 and 100 micro g/ml LPS respectively for 24 hours. Thereafter, the cell proliferation ability was determined by MTT method. The cell apoptosis rate was determined by flow cytometry. The changes in the contents of transforming growth factor beta(1) (TGFbeta(1)) and vascular endothelial growth factor (VEGF) of the supernatant of the cell culture were assessed by ELISA. RESULTS: Apoptosis and TGFbeta(1) secretion could be induced by LPS in dose of 0.1 to 100 micro g/ml when compared with that without LPS challenge (P < 0.05 - 0.01). In detail, LPS in lower dose (0.1, 1.0 and 10.0 micro g/ml) could promote the proliferation of U937 (P < 0.05 - 0.01) but exerted no effect on VEGF secretion. In contrary, LPS in high dose (50 and 100 micro g/ml) could promote VEGF secretion (P < 0.01) but exerted no effects on the proliferation of U937 cells. CONCLUSION: U937 cells could be activated to increase the secretion of TGFbeta(1) by LPS in optimal dose of 0.1 - 10.0 micro g/ml, but the secretion of VEGF could only be promoted by LPS in higher concentration.

Apoptosis↗
PubMed2004

[Study of toxicology of strychnos].

Because of its officinal value, strychnos is widely used by clinic and individual. Since toxic dose and therapeutic dose are very close, strychnos poisoning cases are frequently reported. In this paper the chemical component, toxic dose, mechanisms of toxicity, poisoning symptom and pathological changes after strychnos poisoning are reviewed.

Alkalies↗
PubMed2004

[Effect of temperature on decomposition of leachates by WAO/CWAO].

Catalytic wet air oxidation (CWAO) is a very effective physical chemistry method to treat organic wastewater. In this experiment, CWAO is employed to reduce the organic compounds in the landfill leachates. Temperature is an important factor in treating leachates by CWAO, so the effect of temperature on the reduction efficiency and decomposition rate of organic pollutants is investigated emphatically and the quantificational relationship is established between the decomposition rates and temperatures used in this study. The function of Co/Bi catalyst for the reduction of landfill leachates is also discussed. The influence of temperature on the degradation of landfill leachates by CWAO is carried out in a sealed environment using catalyst. The resulted information shows that the reduction rate of total organic carbon (TOC) and chemical oxygen demand (COD) increases notably with increase in temperature with or without the catalyst, and that the Elovich equation can describe dynamics course of landfill leachates degradation well. Rate constant k also increases with increase in temperature and the quantificational relationship is established between the rate constant k and temperature; the main reason of pH value reducing rapidly at first and later rising slowly is that a large amount of organic acid is produced in the early period in the reaction and the organic acid is degraded gradually later. Degradation of landfill leachates by CWAO can reach better treatment efficiency in gentle condition with catalyst Co/Bi in this study. The temperature's relatively great impact on the reaction using CWAO is discussed only in the paper and the effects of the other reaction conditions such as oxidant and catalyst dosage and the concentration of wastewater on degrading efficiency by CWAO are to be focused on.

Catalysis↗
PubMed2004

[The role of homeobox B2 gene in vascular endothelial proliferation and the protective effects of VEGF on the endothelia against radiation injury].

OBJECTIVE: To explore the role of HOXB2 gene in the proliferation of primary human umbilical vein endothelial cells (HUVECs) and the protective effects of VEGF on the endothelia against radiation injury. METHODS: HUVECs were isolated, cultured, subcultured and identified. (1) Liposome coated oligodeoxynucleotide (odn) and homeoboxB2 antisense oligodeoxyncleotide (HOXB2asodn) were prepared prepared in the concentrations of 0.25, 0.5, 1.0 and 2.5 mg/L for the stimulation of HUVEC. (3)H-TdR incorporation test and MTT method were employed to determine the proliferation activity of HUVECs after activation. The cell cycle analysis of HUVECs was determined by flow cytometry. The expression level of HOXB2mRNA within HUVECs was detected by RT-PCR (reverse transcription polymerase chain reaction). (2) HUVECs were separately treated with the addition of VEGF in concentration of 50 microg/L, by radiation in the dose of 6 Gy or 12 Gy (60)Co gamma gamma ray, or radiation with 12 Gy (60)Co gamma gamma ray followed by the addition of VEGF in dose of 50 microg/L. The cellular morphology was observed and the cellular proliferation activity was determined by MTT method. RESULTS: (1) The proliferation activity of HUVECs could be markedly inhibited by liposome coated HOXB2asodn in comparison to liposome-odn (P < 0.05 or 0.001), and the inhibition effect was positively correlated with the increase in asodn concentration. The cell ratio in S phase and the expression level of the HOXB2mRNA could be lowered by asodn in dose of 2.5 mg/L (P < 0.05 or 0.001). (2) Radiation by (60)Co gamma ray could lead to the nuclear enlargement, vacuolation in the cytoplasm, multiplicity of nucleus and nuclear swelling. The proliferative activity of HUVECs was increased from 0.365 +/- 0.047 and 0.487 +/- 0.022 without radiation to 0.557 +/- 0.042 and 0.648 +/- 0.021 24 and 48 hours after 6 Gy radiation However it was decreased to 0.263 +/- 0.038 and 0.306 +/- 0.024 (P < 0.01) after 12 Gy (60)Co gamma ray radiation. Nevertheless, the cell morphology was obviously improved and the proliferation was enhanced by the addition of VEGF after 12 Gy radiation. CONCLUSION: HOXB2 gene played important roles in the biological activities of HUVECs. Small dose (6 Gy) gamma-radiation could promote, but large dose (12 Gy) could decrease the mRNA expression of HOXB2 gene in HUVECs. In addition, VEGF could protect HUVECs against radiation injury.

Cell Proliferation↗