Biomedical subjects

C Liu

Publications and source records attributed to C Liu.

At least 163 records · Page 9Linked to original sources

PubMed2001

Adenoma of the posterior urethra: 131 case report.

AIM: A case-report on adenoma of the posterior urethra. METHODS: In 131 cases of adenoma of the posterior urethra, aged 17-79 (mean: 36.4) years, a detailed medical history was taken and urinalysis, urethroscopy, and prostatic specific antigen (PSA) immunohistochemical staining were performed. They were then treated with transurethral resection (TUR) or transurethral electric coagulation (TUEC). RESULTS: Hemospermia occurred in 51% of the cases, hematuria in 38%, blood overflow from the urethral orifice in 6%, and dysuria in 5%. The position of the tumor was at or around the verumontanum. The appearance of the tumor was similar to those of a papilla, a villus, a dactyl or polyp, or simply an engorgement. The tumor contained glandular alveoli and adeno-epithelial cells. PSA immunohistochemistry was positive in the cytoplasm and nucleus of the adeno-epithelial cell. One hundred and tweenty-nine cases were cured after TUR or TUEC, while 2 patients recurred and were operated again. CONCLUSION: Adenoma of the posterior urethra is a common cause of hemospermia and hematuria in young men. Urethroscopic examination and biopsy are the principal diagnostic measures. TUR or TUEC are believed to be the treatment of choice with a short-term recurrence rate of around 1. 5%.

Adenoma↗

PubMed2001

[Study of fungus polysaccharides compounds (FPC) in inducing the apoptosis of liver cancer cell Bel-7402].

To observe the influence of fungus polysaccharides compounds (FPC) in inducing human liver cancer cell Bel-7402 apoptosis in cell cultivating in vitro, the authors analyzed tumor inhibitive gene P53 expression in Bel-7402 apoptosis by applying double immuno-marker. The result showed that the multilevel of FPC could all apparently induce Bel-7402 apoptosis. With the enhancement of FPC concentration, the authors observed chromatin condensation in some phases companying with the characteristic apoptosis. In the meantime, it could also greatly reduce the G1 and S, with obviously dose-response relationship. The percentage of cell apoptosis increased with the enhancing of concentration. In the high-level group the authors found typical DNA ladder eletrophoresis stripe. The result showed that the mechanism of the FPC antineoplastic effect had an intimate relation with its induction to apoptosis and that the result of FPC inducing tumor cell apoptosis had the character of P53 independence.

Antineoplastic Agents↗

PubMed2001

Identification of causal relationships among traits related to drought resistance in Stylosanthes scabra using QTL analysis.

Previous studies have shown that a negative relationship exists between transpiration efficiency (TE) and carbon isotope discrimination (Delta) and between TE and specific leaf area (SLA) in Stylosanthes scabra. A glasshouse experiment was conducted to confirm these relationships in an F(2) population and to study the causal nature of these relationships through quantitative trait loci (QTL) analysis. One hundred and twenty F(2) genotypes from a cross between two genotypes within S. scabra were used. Three replications for each genotype were maintained through vegetative propagation. Water stress was imposed by maintaining plants at 40% of field capacity for about 45 d. To facilitate QTL analysis, a genetic linkage map consisting of 151 RAPD markers was developed. Results from this study show that Delta was significantly and negatively correlated with TE and biomass production. Similarly, SLA showed significant negative correlation with TE and biomass production. Most of the QTL for TE and Delta were present on linkage groups 5 and 11. Similarly, QTL for SLA, transpiration and biomass productivity traits were clustered on linkage groups 13 and 24. One unlinked marker was also associated with these traits. There were several markers coincident between different traits. At all the coincident QTL, the direction of QTL effects was consistent with phenotypic data. At the coincident markers between TE and Delta, high alleles of TE were associated with low alleles of Delta. Similarly, low alleles of SLA were associated with high alleles of biomass productivity traits and transpiration. At the coincident markers between trans-4-hydroxy-N:-methyl proline (MHP) and relative water content (RWC), low alleles of MHP were associated with high alleles of RWC. This study suggests the causal nature of the relationship between TE and Delta. Phenotypic data and QTL data show that SLA was more closely associated with biomass production than with TE. This study also shows that a cause-effect relationship may exist between SLA and biomass production.

Alleles↗

PubMed2001

A personal glimpse of clinical infectious diseases: 1949-1999.

We have witnessed the advent of the antibiotic era and the development of potent immunization agents in the second half of the 20th century. These remarkable scientific tools enable us to treat and control infectious diseases effectively. Yet the development of microbial resistance to antimicrobial agents and the emergence of new or previously unrecognized infectious diseases continue to challenge the medical and public health professionals. Most ominously, the ill-natured terrorists and mistrustful administrators in certain nations have capitalized on the modern microbial technology to create means for bioterrorism and biological warfare. When will humans ever learn?

Bacteria↗

PubMed2001

[Study of in vitro cultured microencapsulated adrenal cortical tissues of rats].

In order to investigate the growth of in vitro cultured microencapsulated adrenal cortical tissues of rats, we produced the microcapsules by using sodium alginate, calcium chloride and poly-L-lysine, etc. The adrenal glands were taken out of 24 rats, half of the adrenal glands were microencapsulated (capsule group) while the other half were left free (noncapsule group). After 36 hours' in vitro culture, the concentrations of aldosterone and cortisol in culture solution were measured by radioimmunoassay. The two groups continued to be cultured for 24 and 36 hours with ACTH stimulation. The concentrations of aldosterone and cortisol at 24 and 36 hours were detected respectively. Parts of adrenal cortical tissues were observed under light microscope and electron microscope. The results showed that the concentrations of aldosterone and cortisol in the microencapsulated adrenal cortical tissues were significantly higher than those of noncapsule group (P < 0.01). In the capsule group, the concentration of cortisol after 36 hours' ACTH stimulation was significantly higher than that before ACTH stimulation (P < 0.01). After 24 and 36 hours' ACTH stimulation, the concentrations of aldosterone and cortisol were significantly higher in the capsule group than in the noncapsule group. In the noncapsule group, regardless of ACTH stimulation, no significant change was seen in the concentration of aldosterone and cortisol (P > 0.05). The cellular structure of adrenal tissues remained intact under light microscopic and electron microscopic observations, and the cells remained alive well. These data suggest that in vitro cultured cells of microencapsulated adrenal cortical tissues remain alive well. Microcapsule has not influenced the secretory function of adrenal tissues. Microencapsulated tissues have a good response to ACTH stimulation.

Adrenal Cortex↗

PubMed2001

[Lipopolysaccharide upregulates expression of CD14 gene and CD14 proteins of hepatocytes in rats].

OBJECTIVE: To observe the expression of CD14 mRNA and its protein in rat hepatocytes during endotoxemia. METHODS: The acute endotoxemia model of wistar rats was established by injection of a dose of LPS (5mg/kg, Escherichia coli O111:B4) via the tail vein, then the rats were sacrificed at 3, 6, 12, and 24 hour, respectively. Hepatocytes were isolated from normal and LPS-injected rats by in situ collagenase perfusion technique. Hepatocytes and hepatic tissue were collected to measure the expression of CD14 mRNA and CD14 protein by reverse transcriptase-polymerase chain reaction (RT-PCR) or Western blot analysis. The binding of fluorescein isothiocyanate (FITC)-CD14 polyclone antibody to isolated hepatocytes was also assessed by flow cytometric analysis (FCM). RESULTS: In the rats with endotoxemia, the expression of CD14 mRNA and CD14 protein in hepatic tissue and isolated hepatocytes were stronger at 6, 12 and 24 hour than that in control rats (P<0.01). FCM showed that positive cell numbers of FITC-CD14 in the rats with endotoxemia increased when compared with normal control group (P<0.01). CONCLUSIONS: LPS can markedly upregulate the expression of CD14 mRNA and CD14 proteins in hepatic tissue and isolated hepatocytes.

Animals↗

PubMed2001

[Decomposition of aqueous sodium pentachlorophenolate (PCP-Na) by using TiO2 coating photocatalyst].

Titanium dioxide (TiO2) photocatalysts were coated on hollow glass beads by sodium silicate (Na2SiO3.9H2O) solution. The coated catalysts were characterized by BET, XRD. Their photoactivity were examined using photocatalytic degradation of sodium pentachlorophenolate(PCP-Na) and glucose solution. The impact of catalysts dosage, PCP-Na initial concentration, initial pH and oxygen concentration on reaction kinetics were also studied in detail. The experiments illustrated that the performance of C3-type catalysts was satisfactory. Conditions of the experiments were following: The initial concentration of PCP-Na and CODCr were 10 mg.L-1 and 400 mg.L-1, respectively, and illumination time was 2 hours and catalysts dosage was 2 g.L-1, the removal rates of CODCr and PCP-Na were above 65% and 92% respectively. Optimum dosage of C3-type catalysts was 2-2.5 g.L-1, DO was no less than 3 mg.L-1.

Catalysis↗

PubMed2001

[Protective effects of total paeony glycoside on cerebral ischemia mice].

OBJECTIVE: To investigate effects of total paeony glycoside (TPG) on cerebral ischemia mice. METHODS: The models of decapitative mice and acute cerebral ischemia mice caused by ligation of bilateral common carotid arteries were used. RESULTS: TPG could prolong gasp time of decapatative mice, lessen cerebral water content and decrease permeability of cerebral capillary significantly. CONCLUSION: TPG possesses obvious protective effects on mice of acute cerebral ischemia.

Animals↗

PubMed2001

[Effects of comprehensive intervention on prognosis of isolated systolic hypertension in the elderly].

OBJECTIVE: To study the effects of comprehensive intervention on prognosis of isolated systolic hypertension in the elderly. METHODS: A 12-years prospective and controlled study was conducted with 207 elderly patients of isolated systolic hypertension enrolled. According to the study project and procedure, 99 patients were allocated to the intervention group and 108 patients in the control group. All the events of cardiovascular diseases, cerebrovascular disorders, nephrovascular diseases and death were recorded and analyzed. RESULTS: A 12-year consecutive follow-up showed that the incidence and mortality of cardiovascular diseases, cerebrovascular disorders, nephrovascular diseases and their ages at death were 41.49%, 26.60% and 75.6 years, respectively, in the intervention group, and 77.45%, 53.92% and 70.2 years, respectively, in the control group, with statistically significant difference. Survival rate in the intervention group was higher than that in the control group. CONCLUSION: Comprehensive intervention for a long time could remarkably improve their clinical prognosis of the elderly patients with isolated systolic hypertension.

Aged↗

PubMed2001

[Fluoride emission from different soil minerals at high temperatures].

The emission characteristics of fluoride pollutants from montmorillonite, kaolinite, vermiculite, geothite and allophane were studied to elucidate the mechanism of fluoride-releasing from soils during brick and tile making at high temperatures from 300 degrees C to 1000 degrees C. The rate of fluoride emission varied with temperature, mineral type, heating time, specific surface area and cations added to minerals. The escape of crystalline water resulting from crystal lattice collapse at a certain high temperature was found to affect the rate of fluoride emission. Calcium compounds could decrease fluoride emission rate from montmorillonite. At 800 degrees C, the rate of fluoride emission from Ca-treated montmorillonite decreased by 59.6% compared to untreated montmorillonite. The order for fluoride-fixing capacity of the 5 calcium compounds at 800 degrees C was as follows: CaCO3 > CaO > Ca3(PO4)2 > Ca(OH)2 > CaSO4.

Aluminum Silicates↗

PubMed2001

[Computer simulation of HA influence on copper bioavailability to the fish gills].

Copper speciation in the gill microenvironment of neon terris (Paracheirodon innesi) and the influence of humic acid and pH on copper bioavailability were investigated using exposure experiment and chemical equilibrium calculation. It was found that the copper speciation was changed because of the influence of the humic acid. With the existence of humic acid, the dominant species of copper in the bulk solution was humic acid complexed copper. However, humic acid complexed copper along with mucus complexed copper dominated the fish gill microenvironment. Consequently, the bioavailable copper species both in the bulk solution and in the fish gill microenvironment were significantly reduced by humic acid. The result of the modeling also indicated that the influence of pH was more significant under alkaline condition.

Animals↗

PubMed2001

[Application of dhfr gene negative Chinese hamster ovary cell line to express hepatitis B virus surface antigen].

OBJECTIVE: To set up an efficient expressing system for recombinant hepatitis B virus surface antigen (HBsAg) in dhfr gene negative CHO cell line. METHODS: HBsAg gene expressing plasmid pCI-dhfr-S was constructed by integrating HBsAg gene into plasmid pCI which carries dhfr gene. The HBsAg expressing cell line was set up by transfection of plasmid pCI-dhfr-S into dhfr gene negative CHO cell line in the way of lipofectin. RESULTS: Under the selective pressure of MTX, 18 of 28 clonized cell lines expressed HBsAg, 4 of them reached a high titer of 1:32 and protein content 1-3 micrograms/ml. CONCLUSION: In this study, the high level expression of HBsAg demonstrated that the dhfr negative mammalian cell line when recombined with plasmid harboring the corresponding deleted gene can efficiently express the foreign gene. The further steps toward building optimum conditions of the expressing system and the increase of expressed product are under study.

Animals↗

PubMed2001

[Heat stress-induced HSP70 expression in heart and vessels of simulated weightless rats].

To examine the effect of simulated weightlessness on inducible HSP70 expression in the heart and vessel tissues of rats, a tail-suspension rat model was used to simulate weightlessness. HSP72 mRNA and HSP70 expression in heart and vessel tissues of both simulated weightless and control rats exposed to heat stress (ambient temperature, Ta = 43 degrees C) and recovered at Ta of 25 degrees C for 1 h (CON-H1, SUS-H1) or 2 h (CON-H2, SUS-H2) were analyzed using Northern blot and Western blot. The expression of HSP72 mRNA in the myocardium significantly decreased in SUS-H2, as compared with that of CON-H2 rats. The amount of HSP72 in the myocardium tended to decrease in both SUS-H1 and SUS-H2 groups, as compared with the corresponding control groups, but the differences were not statistically significant. The levels of inducible HSP70 expression in the vessels were related with their anatomical locations, for that the expression of both HSP72 mRNA and HSP72 significantly increased in basilar arteries, whereas it showed a slight decline in femoral arteries. The blunted HSP70 expression in myocardium suggests that simulated weightlessness may induce myocardial changes similar to those in aging. However, the HSP70 expression changes in arteries are in accord with the trend of differential adaptation changes in vessels to simulated weightlessness.

Animals↗

PubMed2001

[Changes of lipid peroxidation in liver fibrogenesis induced by dimethylnitrosamine and drugs' intervention].

OBJECTIVE: To investigate the pathological actions of lipid peroxidation implicated in liver fibrogenesis induced by dimethylnitrosamine (DMN), and the mechanism of Fuzheng Huayu 319 decoction (319 decoction) and interferon-gamma (IFN-gamma) actions against liver fibrosis. METHODS: A liver fibrotic model was induced by intraperitoneal injection of DMN in rats, and treated with 319 decoction and IFN-gamma, respectively. The liver sections were stained with HE and ponceau for collagens, and the liver functions were assayed. The contents of hepatic hydroxyproline (Hyp) and malondialdehyde (MDA) and the activities of superoxide dismutase (SOD) were measured. The correlation among SOD, MDA and Hyp was analyzed. RESULTS: In the models, hepatic collagens proliferated remarkably and fibrous septa were formed. Serum ALT activities increased. Both Hyp and MDA enhanced obviously, but SOD decreased markedly. SOD was significantly negatively correlated with MDA and Hyp, respectively (r=-0.70, -0.73, P<0.01), and MDA was significantly positively correlated with Hyp (r=0.88, P<0.01). While both 319 decoction and IFN-gamma attenuated collagen proliferation and deposition, decreased ALT level, increased SOD activity, but decreased MDA and Hyp contents. CONCLUSIONS: DMN can cause hepatic lipid peroxidation, which is closely involved in liver fibrogenesis induced by DMN. The effect against hepatic lipid peroxidation is one of the important mechanisms of 319 decoction and IFN-gamma actions against liver fibrosis.

Animals↗

PubMed2001

[Cytotoxic T lymphocyte activity induced by genetic immunization with NV-HC/NS].

OBJECTIVE: To investigate the immunoprophylactic and immunotherapeutic effects of DNA vaccine (NV-HC/NS(3)) after inoculation of mice by target tumor loading technique. METHODS: Before or after inoculation with NV-HC/NS(3) intramuscularly, BALB/c mice in the experimental group were planted with target tumor cells (SP2/0-NS(3)), which were derived from BALB/c mice and stably transfected with the recombinant plasmid NV-HC/NS(3). Tumor growth and survival rate of the mice immunized with NV-HC/NS(3) were compared with those in the control group. RESULTS: Tumor mass grew well in all mice in the control group in a few days, while no visible tumor mass growth in 40% mice immunized with NV-HC/NS(3) could be seen. The survival rate and life span of mice in the experimental group were significantly longer than those in the control group. CONCLUSIONS: Specific immune activity could be induced by immunization with NV-HC/NS(3). Such effects are immunoprophylactic and immunotherapeutic.

Animals↗

PubMed2001

The early growth response gene EGR-1 behaves as a suppressor gene that is down-regulated independent of ARF/Mdm2 but not p53 alterations in fresh human gliomas.

PURPOSE: EGR-1 is an immediate early gene with diverse functions that include the suppression of growth. EGR-1 is down-regulated many cancer cell types, suggesting a tumor suppressor role, and may critically involve the p53 pathway. The aim of this work was to measure the expression of EGR-1 and the p16/INK4a/ARF-Mdm2-p53 pathway status in fresh human gliomas. EXPERIMENTAL DESIGN: Thirty-one human gliomas with different grades of malignancy were investigated for Egr-1 mRNA and the protein expression, frequency, and spectrum of p53 gene mutations, mdm2 gene amplification, and p16/INK4a/ARF allele loss. RESULTS: The amplification of Mdm2 and the deletion of the p16/INK4a gene was found in 3 and 5 cases, respectively, whereas mutations of p53, including two novel mutations, were observed in 10 other cases. The three types of changes occurred strictly mutually exclusively, emphasizing that these genes operate in a common pathway critical to glioma progression. EGR-1 mRNA was significantly down-regulated in astrocytomas (14.7 +/- 5.1%) and in glioblastomas (33.6 +/- 10.0%) versus normal brain. Overall, EGR-1 mRNA was strongly suppressed (average, 15.2 +/- 13.9%) in 27 of 31 cases (87%), independent of changes in p16/INK4a/ARF and Mdm2; whereas 4 of 31 cases with residual EGR-1 expression as well as the highest EGR-1 variance segregated with p53 mutations. Immunohistochemical analyses confirmed the suppression of EGR-1 protein. CONCLUSIONS: These results indicate that EGR-1 is commonly suppressed in gliomas independent of p16/INK4a/ARF and Mdm2 and that suppression is less crucial in tumors bearing p53 mutations, and these results implicate an EGR-1 growth regulatory mechanism as a target of inactivation during tumor progression.

Blotting, Northern↗

PubMed2001

Comparison of human, mouse, rat, and guinea pig histamine H4 receptors reveals substantial pharmacological species variation.

The recently identified histamine H4 receptor has revealed a potential new complexity for the role of histamine in the immune system. To begin to understand the role of this receptor in humans, one must first determine whether homologs exist and can be studied in lower species. To address this, we cloned the rat, mouse, and guinea pig cDNAs corresponding to the recently identified human histamine H4 receptor. The rat, mouse, and guinea pig H4 sequences are significantly different from the human H4 sequence at 69, 68, and 65% homology, respectively. The tissue distribution of the rat, mouse, and guinea pig H4 receptors is similar to human in that bone marrow and spleen are the most abundant sources of expression. The human and guinea pig H4 receptors display the highest binding affinity for [3H]histamine (KD = 5 nM each), whereas the affinities for rat and mouse receptors are substantially lower at 136 and 42 nM, respectively. With respect to the pharmacological profile of known H3/H4 ligands, even greater differences in binding affinities exist among the species homologs. There are also substantial differences in the signal transduction response to each of the four species of H4 receptor. This work demonstrates the existence of histamine H4 receptors in lower species and demonstrates that a clear knowledge of each species pharmacological profile will be essential to elucidate the role of this receptor subtype in vivo.

Amino Acid Sequence↗

PubMed2001

[HCV core protein activates expression of vascular endothelial growth factor in HepG(2) cells].

OBJECTIVE: To explore the effect of HCV core protein on vascular endothelial growth factor (VEGF) in HepG(2) cells. METHODS: The HCV core gene cDNA was recoverd by PCR, and cloned into PBK-CMV. The recombinant plasmid (PBK-HCVc) and the vector-alone were transfected into HepG(2) cells with liposome. After being selected with G418,resistant colonies were obtained. The reverse transcription PCR and Western blot was analyzed to show HCV core protein expression. VEGF was analyzed by immunohistochemical and Western blot; VEGF mRNA was analyzed by in situ hybridization and reverse transcription PCR. RESULTS: The results suggest that the recombinant plasmid could express HCV core protein efficiently under the control of vector's promoter. The VEGF of HepG(2)-C cells was higher than that of HepG(2)-CMV. CONCLUSIONS: HCV C protein can activates the expression of VEGF in HepG(2) cells and may contributes to viral carcinogenesis.

Endothelial Growth Factors↗