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Biomedical subjects

B Liu

Publications and source records attributed to B Liu.

At least 325 records · Page 18Linked to original sources
PubMed1999

[Study on the inhibition of nude mice transplantation tumor growth by telomerase ribozyme].

OBJECTIVE: To explore whether telomerase ribozyme could inhibit the growth of nude mice transplantation tumor. METHODS: A xenograft human-nude mouse model was constructed. A total of 24 mice were divided into 4 groups, namely, the saline control(Group 1), the blank plasmid control(Group 2), the 20 microg/mouse/day p(XJ-neo-teloRZ)(Group 3) and the 30 microg/mouse/day p(XJ-neo-teloRZ)(Group 4). All plasmids were packaged by lipofectamine and used for subcutaneous, continuous infusions over 14 days. Tumor measurements and observations of animal behavior were recorded daily. On completion of the study, the mice were killed by cervical dislocation and their organs were removed, weighed, and stored in formaldehyde for histological examination. The telomerase activities of tumor tissues of each group were also detected. RESULTS: The telomerase ribozyme effectively inhibited the telomerase activities of tumor tissues and promoted the apoptosis of tumor cells. The in vivo studies showed a significant decrease in tumor size in mice treated with p(XJ-neo-teloRZ) when compared to the mice treated with controls. Furthermore, the in vivo effect of p(XJ-neo-teloRZ) was dose dependent. CONCLUSION: Telomerase ribozyme is a powerful telomerase inhibition agent; probably it could be effective in tumor gene therapy.

Animals↗
PubMed1999

New experimental model to study the bone interface of endosseous implants: an in vitro three-dimensional model of cell culture.

To set up a three-dimensional culture model of endosseous implant material-osteoblast, titanium (Ti) discs were placed onto confluent cellular layers of human fetal osteoblasts that were cultured in calcifying conditions. Follow-up observations of living cells with phase-contrast microscopy and histological observations of the cell-Ti disc interface with ordinary microscopy and transmission electron microscopy were used to monitor and verify the formation of three-dimensional cellular structures at the osteoblast-Ti disc interface. These methods were further used to study osteoblast cell behavior during the early stage of bone healing in this three-dimensional cellular model. The follow-up observation showed that, upon the placement of the Ti disc, cells migrated from the cellular layer and attached to the rim of the disc, forming cell bridges. Cells continued to attach and orient throughout the culture time. A cellular multilayer at the osteoblast-Ti interface was formed, which resulted in the three-dimensional model. Furthermore, transmission electron microscopy observation showed that there was a mineralizing process at the osteoblast-Ti disc interface just like bone, which confirms the reality of this model. Histological observations with conventional microscopy demonstrated the interfacial relation between biomaterial and cells. If osteoblasts were replaced by other types of cells, this model could be used to study the other kinds of interfaces.

Cell Adhesion↗
PubMed1999

[Study on the reversal of cancer multidrug resistance by Chinese medicine Fw13-te41 in nude mice].

We have reported that three reversal agents were sifted out from 32 Chinese galenicals through a series of cell culture tests. Among them, Fw13-te41 has the best effect of reversal cancer multidrug resistance (MDR) in vitro. In this study, the reversal action of Fw13-te41 in vivo was studied on the animal model of nude mice with human leukemia k562/ADR. Twenty SPF BALB/c-nu/nu nude mice with xenograft tumor were randomly divided into the control group (n = 6), VCR group [intraperitoneal (i.p.) VCR 250 micrograms/week, n = 5], VCR + Fw13-te41 group (i.p VCR 250 micrograms/week + Fw13-te41 0.2 ml/day, equivalent to crude drug 10 g/kg, n = 5), and Fw13-te41 group (i.p Fw13-te41 0.2 ml/day, equivalent to crude drug 10 g/kg, n = 4). After 18 days, the rate of tumor inhibition (RTI) of VCR group was 19.79%, but the RTI of VCR + Fw13-te41 group was as high as 86.95% (P < 0.05). There results demonstrate that the Chinese medicine Fw13-te41 has an evident reversal action of malignancy MDR in vitro and in vivo.

Animals↗
PubMed1999

[Effect of human plasma HDL on the HDL receptors of plasma membranes of cholesterol-fed rabbit].

Atherosclerosis(As) rabbit model was developed by high-cholesterol feeding for 12 weeks. The rabbits were injected intravenously with human plasma HDL preparation per week, and then the effects of HDL on the lipids contents of serum, liver and bile nd the activity of HDL receptors on liver plasma membranes of cholesterol-fed rabbit were investigated. The results showed that HDL preparation had no effect on decreasing the lipids contents of serum, but it could low down the lipid depositions in liver, and promote the excretion of lipids from bile. The value of Bmax of HDL receptor showed decreasing trendy and the value of Kd showed increasing trendy in cholesterol-fed rabbits. In HDL-treated rabbits, the value of Bmax increased significantly as compared with that of normal group(P < 0.05), but the value of Kd showed no difference. The results suggested that human plasma HDL could enhance the activity of HDL receptors on the liver plasma membranes of cholesterol-fed rabbit.

Animals↗
PubMed1999

[Apolipoportein E polymorphism, serum lipids and apolipoproteins of 362 Han national subjects in Chengdu area].

This investigation was conducted to observe the frequency distribution of apoE phenotypes and alleles and to explore the relationship between apoE polymorphism and plasma lipids or apolipoproteins in Chinese population. ApoE phenotypes were assayed by isoelectric focusing and immunoblotting with serum. Serum lipids and apoA I, B100, C II, C III, E were determined in a random subset of 362 subjects including 268 males and 94 females with a mean age of 43.7 +/- 12.3 yrs from a population of Han Nationality in Chengdu area. The results showed that the frequencies of apoE phenotypes and alleles were: E3/3 72.93%, E2/3 12.98%, E3/4 11.33%, E2/4 1.38%, E4/4 1.38%, E2/2 0.00%; epsilon 3 0.8508, epsilon 2 0.0718, epsilon 4 0.0774. The results also showed that the apo E2(E2/3 + E2/2) group had lower levels of serum TC and apoB100 (P < 0.05) and a higher level of serum apoE (P < 0.001) when compared with the apoE3(E3/3) or apoE4(E3/4 + E4/4) group. No significant difference was observed in TG, apoA I, apoC II, and apoC III levels among the apoE2, E3 and E4 groups (P > 0.05).

Adult↗
PubMed1999

Effects of the configuration of a multi-epitope chimeric malaria DNA vaccine on its antigenicity to mice.

OBJECTIVE: Four B and Th cell epitopes were selected from conservative domain of Plasmodium falciparum antigens to construct two groups of chimeric malaria DNA vaccines with different configurations and their antigenicities were studied. METHODS: The partially synthesized oligonucleotide was annealed, PCR amplified and cloned into a mammalian cell expression vector. By using a pair of isocaudamers on the vector, different single copies of B epitopes were multiplied and were tenderly stringed into two groups of chimeric DNA vaccine with different configurations. BALB/c mice were immunized with these DNA plasmids by either intramuscular or intradermal injections. RESULTS: The antisera from the immunized mice tested by ELISA showed that only the configuration which had a single copy of universal T helper cell epitope, CS. T3, located at the C terminal of the multi-copy B cell epitopes induced a high antibody response. The T helper cell epitope at any other position of the peptide, or the double T helper cell epitopes configured with the B cell epitopes did not enhance antibody response, and some configurations even decreased the humoral response to a B cell epitope. CONCLUSION: This study demonstrated that both combination and configuration of the epitope may affect the antigenicity of a chimeric multiple antigen.

Animals↗
PubMed1999

[Regulation of gene co-expression after bicistronic retrovirus-mediated gene transfer into human cord blood CD34+ cells].

OBJECTIVE: To compare internal SV40 early promoter with IRES of the in regulatory effect on gene co-expression after retrovirus-mediated gene transfer into human cord blood CD34+ cells. METHODS: Based on pLXSN, vectors pLESN and pLEIN carrying EGFP and neo gene, distinguished by the in sequences between two, genes, were constructed. After liposome-mediated gene transfer into packaging cells, high-titre virus supernatant was obtained. After supernatant infection in vitro, transduced cells were cultured in CFC assay. RESULTS: FACS analysis demonstrated that 10% of human cord blood CD34+ cell were infected in vitro. All of G418 resistant colonies demonstrated green fluorescence in LEIN group, while only 41.1% in LESN group. CONCLUSION: IRES is superior to SV40 promoter for the guarantee of co-expression in bicistronic retrovirus-mediated gene therapy in human cord blood CD34+ cells.

Adenoviruses, Human↗
PubMed1999

A feasible and effective technique for the detection of Schistosoma japonicum cercaria-infested water.

OBJECTIVE: To develop a new technique for detecting Schistosoma japonicum (S. japonicum) cercariae so as to predict the distribution of area with high transmission potential and to control acute infection of schistosoma. METHODS: A C-6 film was established and used to adhere the cercariae on water surface and compared with a few other conventional detecting techniques. RESULTS: The average rate of the cercaria-recovery was 40% in laboratory and field using C-6 film, which was 20 times higher than that of traditional nylon-tissue adsorbing and precipitating method. Either in some areas where oncomelania were present or in some places where the snail had been under control, the technique could detect the cercariae. CONCLUSION: The technique can be characterized by a feasible, economical, promptly accessible method, especially for field application.

Animals↗
PubMed1999

Nitric oxide synthase/nitric oxide pathway mediates intussusception pathogenesis in rats.

OBJECTIVE: To study the role of nitric oxide synthase/nitric oxide pathway in the pathophysiological process of intussusception (IN). METHODS: The IN model of rat was induced by lipopolysaccharide (LPS). The content of NOx in plasma and the NOS activity in colic smooth muscle tissues were measured. The content of cGMP was determined by radioimmunoassay. RESULTS: LPS (10 mg/kg, i.p.) induced IN in up to 40% of the rats 6 hours after treatment with LPS. The incidence of IN was significantly increased by 58.3% (P < 0.05) and by 66.8% (P < 0.01) in L-arginine (L-Arg)-treated rats (2% in drinking water) and in sodium nitroprusside (NSP)-treated rats (1 mg/kg, i.p.), respectively, but it is significantly decreased by 66.8% (P < 0.01) after administration of M-omega-nitro-L-arginine methyl ester (L-NAME, 15 mg/kg, i.p.), an inhibitor of nitric oxide synthase (NOS) activity. Furthermore, LPS increased total NOS activity, NOx production and cGMP levels in plasma or in colic smooth muscle tissues. These parameters in LPS-IN rats were significantly elevated by 38.8%, 50.7%, and 48.7% respectively (P < 0.01) compared with LPS-non-IN rats. CONCLUSION: NOS/NO pathway plays an important role in the process of IN, and inhibition of NO production may serve as a possible approach to prevent IN.

Animals↗
PubMed1999

[Clinical study on effect of shenqi fuzheng injection combined with chemotherapy in treating gastric cancer].

OBJECTIVE: To assess the clinical effect of Shenqi Fuzheng Injection (SQFZI) combined with chemotherapy in treating gastric cancer. METHODS: One hundred and twenty patients were randomly divided into 3 groups, the combined therapy group (Group A), the chemotherapy group (Group B) and the SQFZI group (Group C) and the effect on remission and stabilization of patients were observed. RESULTS: The remission rate and stabilizing rate of Group A were 16.1% and 87.1%, those of Group B were 13.5% and 64.9%, the difference between the two groups was significant, P < 0.05. The symptom and living quality improving rate of Group A were 75.8% and 43.5% respectively, those of Group C were 61.9% and 57.1% and of Group B were 35.1% and 29.7% respectively. SQFZI showed good protective effect on hemopoietic system, 4.8% patients in Group A with WBC count lower than 4 x 10(9)/L, while the percentage reached 21.6% in Group B, the difference between the two groups was significant, P < 0.05. Moreover, SQFZI could raise activity of NK cell, macrophage and T-lymphocyte subgroups, without any injury on heart, liver and kidney function or other adverse reaction. CONCLUSION: SQFZI combined with chemotherapy has certain effect of remission and stabilization on gastric cancer, the clinical effect is significant to patients with Qi-Deficiency, and is reliable and safe.

Adult↗
PubMed1999

[Selective arterial embolization for the treatment of thoracolumbar spinal tumor].

OBJECTIVE: To decrease intraoperative blood loss during tumor resection. METHODS: Fifteen patients with primary thoraco-lumbar spinal tumor [giant cell tumor (5 patients), malignant nerinoma (2), chordoma (1), fibrous xanthosarcoma (1), malignant fibrohistocytoma (1), osteosarcoma (1), Ewing sarcoma (1), myeloma (1), leimyosarcoma (1), Non-Hodgkin diseases (1)] were treated by means of preoperative selective arterial embolization, tumor resection, and spinal reconstruction. Eight patients were subjected to total spondylectomy in one stage. RESULTS: Fourteen patients showed satisfactory results after embolization. The volume of intraoperative blood loss ranged from 3,000 ml to 400 ml (average 1,200 ml). Follow up of the patients varied from 8 months to 19 years (average 48.7 months). Local recurrence happened in 3 patients; 3 patients died from metastasis. Three of 4 patients recovered from complete bowel movement and urination. Seven of nine patients had musical strength improved. Six of 8 patients had recovery of the e sensation of the lower limbs. CONCLUSIONS: Selective arterial embolization before operation followed by operation within 24 hours can reduce intraoperative blood loss, shorten operative time, and provide a clear operative field for tumor resection.

Adolescent↗
PubMed1999

[Experimental study of osseointegrated dental implants placed into fresh extraction sockets in dogs].

OBJECTIVE: To investigate the better way in treating bone defects around implants. METHODS: 12 mongrel dogs, pure titanium implants were immediately inserted in the mesial roots of the second, third and fourth mandibular premolar sockets. The defects around implants were separately filled with demineralized freeze-dried bone allograft (DFDBA), demineralized freeze-dried allocancellous in combination with bBMP (bBMP compound bone) and nothing. RESULTS: Histologic observation showed that bone defects around implants were substituted by new bone in DFDBA group at 12 weeks and in bBMP compound bone group at 8 weeks, and also the osseointegration were obtained between implants and bone, but bone defects were only filled about 3/5 in no graft group at 12 weeks. CONCLUSION: Immediate implants could obtain good osseointegration if the defects around implants were treated properly and the right technique was used, and also the use of bBMP compound bone could promote obviously bone formation in defects around implants.

Animals↗
PubMed1999

[Component in diphtheria-pertussis-tetanus-hepatitis B vaccine].

OBJECTIVE: To study immunogenecity of yeast-derived recombinant hepatitis B (YHB) component in diphtheria-pertussis-tetanus-YHB vaccine (DPTw-YHB). METHODS: Immunogenecity of tetra-valent DTPw-YHB vaccine and mono-valent recombinant YHB vaccine, and that of the tetra-valent vaccine with varied YHB component were compared. The efficiency and stability of recombinant YHB in the tetra-valent vaccine stored at 2 - 8 degrees C for 18 months were determined. RESULTS: The efficiency of recombinant YHB in the tetra-valent vaccine enhanced significantly in mice, as compared with that of mono-valent recombinant YHB vaccine, with an average mouse ED(50) of 1:2.0 - 1:3.1. There was no significant difference in efficiency of the tetra-valent vaccine with varied recombinant YHB component. Recombinant YHBin the DPTw-YHB tetra-valent vaccine still kept good stability stored at 2 - 8 degrees C for 18 months. CONCLUSION: Recombinant YHB in the tetra-valent vaccine was more immunogenic than the mono-valent YHB vaccine. No interference and inhibition of DPTw to recombinant YHB was found, indicating good compatibility between DPTw and YHB.

Animals↗
PubMed1999

[Effects of danshen and shengmaiye on glomerulosclerosis by adriamycin in rats].

OBJECTIVE: To investigate the effects of danshen(Salvia plectranthoides Griff.) and shengmaiye (Panax ginseng C. A. Mey, Ophiopogon japonicus Ker-Gawl and Schisandra chinensis Baill) on glomerulosclerosis induced by adriamycin in SD rats. METHODS: Left kidney of the animals was removed and after 7 days, adriamycin(6 mg.kg-1) was injected through tail vein, so as to establish an animal disease model. Then danshen or shengmaiye was injected to peritoneal cavity of the rats. All rats were killed by the end of the 8th week. Hemoglobin, BUN, cholesterol and protein in urea within 24 hours(ur Pro/24 h) were detected. IV collagen(IV col.) and laminin(LN) of renal cortex were determined by ELISA. The quantitation of IV col and LN in glomerular mesangial area was analyzed by computer pictures. RESULTS: Compared with model-danshen group(Group III), model-shenmaiye group(Group IV) and normal control group(Group I), BUN, cholesterol(Ch) and ur Pro/24 h were increased obviously and hemoglobin(Hb) was decreased in model control group(Group II). The values of BUN, Ch and Ur Pro were lower in Group III and Group IV than those in Group II and higher than those in Group I (P < 0.05). The quantitation of IV col and LN within renal cortex and mesangial area was less in Group III and Group IV than that in Group II and more than that in Group I (P < 0.05 or P < 0.01). CONCLUSION: Dansheng and shengmaiye may play an important role in the treatment of glomerulosclerosis in rats.

Animals↗
PubMed1999

[Studies on chemical constituents in the fruit of Canarium album Raeusch].

OBJECTIVE: To study the chemical constituents in the fruit of Canarium album. METHOD: Compounds were isolated by chromatography and elucidated on the basis of spectroscopic analysis. RESULT: The compounds obtained were determined as scoparone, scopoletin, (E)-3,3'-dihydroxy-4,4'-dimethoxystilbene and gallic acid. CONCLUSION: All the compounds, except gallic acid, were obtained from this plant for the first time.

Burseraceae↗
PubMed1999

[Plasma HDL subfractions in endogenous hypertriglyceridemia].

Our previous studies indicated that while the plasma triglycerides (TG) levels were significantly increased, HDL-C and apo A I levels were significantly decreased and abnormal HDL compositions were found in hypertriglyceridemic (HTG) patients. Whether the particle sizes of plasma HDL in HTG undergo a change has not yet been reported. This study was designed to observe the changes of plasma HDL subfractions in HTG patients. The plasma TG, total cholesterol (TC), HDL-C, apo A I, A II, B100, C II, C III, and E, HDL compositions and HDL subfractions--HDL2a, HDL2b, HDL3a, HDL3b and HDL3c were measured in 25 HTG patients (plasma TG > 2.26 mmol/L, TC < 6.72 mol/L) and 25 age-sex matched healthy subjects (plasma TG < 1.69 mmol/L, TC < 5.17 mmol/L). Plasma HDL was isolated by one step density gradient ultracentrifugation. Plasma and HDL TC, TC were determined by enzymatic methods; apo A I, A II, B100, C II, C III and E were measured by RID kits developed by ourselves. HDL subfractions were analyzed by a gradient gel electrophoresis method (GGE). The variation coefficients in one gel were 2.3% to 8.3% and the variation coefficients among gels were 3.5% to 9.3%. The results indicated that in the HTG group, the fasting plasma TG, apo B100, C II, C III and E levels were significantly higher (P < 0.001) and HDL-C, apo A I levels were lower (P < 0.05) as compared with those in the control group. TC in HDL in the HTG group were significantly increased (P < 0.05), while TG, apo A I, C II, C III and E were significantly decreased (P < 0.05, P < 0.01). Among HDL subfractions in the HTG group, HDL2b was significantly decreased (P < 0.02); HDL2a and HDL3a were increased (P < 0.05, P < 0.02). With the increase of plasma TG levels in the HTG group, the HDL particle sized tended to become smaller. According to the results, it is suggested that the changes of plasma HDL subfractions in HTG are related to the changes of the apolipoprotein compositions of HDL, which lead to the increase of HDL catabolism, therefore the plasma HDL2b content decreases and HDL2a, HDL3a contents increase.

Adult↗
PubMed1999

[Effects of insulin on synthesis and secretion of apolipoproteins A I, A II, B100, C III and E by cultured HepG2 cells].

This study was intended to observe the effects of insulin on synthesis and secretion of apolipoproteins by hepatic cells. The HepG2 cells were cultured in RPMI 1640 media with bovine insulin (1 microgram/ml media and 10 micrograms/ml media) for 72 hours, and the apolipoproteins contents in cultured media were measured by radioimmunodiffusion assay (RID) kits developed by authors' research laboratory. 40 fold lyophilizely condensed culture media were used for the assays. The results showed that the relative amounts of apo A I, A II, B100, C III and E secreted by HepG2 cells detected by this method were 824 +/- 27, 813 +/- 24, 4875 +/- 82, 597 +/- 74 and 97 +/- 4 ng/mg cell protein, respectively. When 1.0 microgram/ml medium of bovine insulin was added into the culture media, apo A I and apo E secretion remained unchanged. When compared with the control, while apo A II tended to decrease, apo C III tended to increase, and apo B100 secretion decreased by 21.2%; when 10.0 micrograms/ml medium of insulin was added, apo A I, A II and B100 secretion decreased by 6.9% (P < 0.05), 44.3% (P < 0.01) and 29.3% (P < 0.01) respectively, while apo C III secretion increased by 51.8% (P < 0.01). These results support certain parts of the hypothesis of pathogenesis of Chinese endogenous hypertriglyceridemia proposed by Bing-Wen Liu.

Apolipoprotein A-I↗