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Biomedical subjects

B Liu

Publications and source records attributed to B Liu.

At least 397 records · Page 22Linked to original sources
PubMed1998

[Reversal of cancer multidrug resistance by Chinese medicine Ams-11, Fw-13 and Tul-17].

The aim of this project was to find some kinds of Chinese materia medica as effective agents for in vitro reversal of cancer multidrug resistance. Based on the present authors' previous researches, thirty-two kinds of Chinese medicine as research meterials were selected and examined. Using cell growth inhibit assay, the authors found that three of them--Ams-11, Fw-13 and Tul-17 in the doses free from cytotoxity could enhance the sensitivity of multidrug resistant cells to anti-cancer drugs in a dose-dependent way. It seemed that these three kinds of Chinese medicine might be potential effective reversal agents.

Cell Survival↗
PubMed1998

[Isoelectric focusing and immunoblotting identification of human ApoE phenotype].

A simple, rapid and accurate method for phenotyping sera apoE has been developed. In this method 10 microliters serum or plasma are incubated with Dithiothreitol and Tween-20 for 15 min and then applied to 5% polyacrylamid gel containing pH 4-8 ampholyte and 3 mol/L urea. After 2 h focusing, the apoE bands are transferred to Nitrocellulose membrane. apoE bands are made visible by immunoblotting and TMB is used as the substrate. Identification phenotype is easily accomplished by noting the location and number of protein bands. 56 samples shows apoE 3/3 in 47 cases, apoE 2/3 in 2 cases, and apoE 3/4 in 7 cases. This method is well suited for large-scale population studies and clinical labs.

Apolipoproteins E↗
PubMed1998

[Qualitative and quantitative analyses of telomerase activity in cultured cells].

In this study, we established a qualitative PCR-TRAP assay by using SYBR Green stain instead of EB stain; this modification based on Kim's method raised the sensitivity of telomerase detection by 25-100 fold. Besides, a quantitative assay was established by us using 32P-ATP labeled TS primer and the internal control TSK1. We detected the telomerase activity of 12 cultured cells by means of these two assays. The results showed that the telomerase activity could be detected in all the cells, but the activity levels of the cells differed prominently (from 23 to 652 TPG units). The establishment of PCR-TRAP assay and especially the establishment of quantitative assay have enabled us to evaluate the telomerase activity of cells more accurately, and they can be used in our further studies of tumor gene therapy by reducing the telomerase activity of tumor cells.

Breast Neoplasms↗
PubMed1998

[Effect of Ox-LDL on cell cycling phases and PCNA, P53, P27 and c-erbB-2 expression in cultured human arterial smooth muscle cells].

It was found in our previous study that oxidative modification LDL (Ox-LDL) could stimulate the proliferation of cultured human arterial smooth muscle cells (SMC). Yet, the mechanism responsible for the SMC proliferation induced by Ox-LDL is not clear. Proliferating cell nuclear antiger (PCNA), P53 and P27 are the key regulatory factors of cell replication. In order to observe the effects of Ox-LDL on cell cycling phase and PCNA, P53, P27 and c-erb B-2 expression in SMC, we used the flow cytometric method in the present study on the proliferation of cultured human SMC induced by Ox-LDL. The results showed a relation between the Ox-LDL mediated SMC proliferation and the cycling phase shifting. The relative number of S phase cells in the Ox-LDL group was higher than that of the control group (22.9% vs 15.7%). Ox-LDL mediated SMC proliferation was accompanied with the increasing expression of PCNA. The percentage of specific PCNA positive FITC cells in the Ox-LDL group was significantly higher than that of the control group (12.6% vs 6.5%). PMA, an activitor of protein kinase C (PKC), stimulated SMC proliferation and increased the PCNA exression in cultured SMC, while the PKC inhibitor, F109203X, significantly decreased the PCNA expression in SMC (PCNA positive cells 13.4% vs 0.4%). No changes were observed in the expression of P53, P27 and c-erb B-2 in the cultured proliferating SMC induced by Ox-LDL. In all, the results suggest that the OX-LDL mediated SMC proliferation is related to increasing S Phase Cells and involved in the PCNA expression which might undergo the PKC cellular signal transduction pathway.

Aorta↗
PubMed1998

[Inhibition effect of Swainsonine on the growth and metastasis of gastric cancer in vivo].

OBJECTIVE: To study the immunomodulating effect of Swainsonine (SW), an inhibitor of alpha-mannosidase II, and the inhibiting effect on the growth and metastasis of gastric cancer. METHODS: Nude mice with human gastric cancer xenograft orthotopically implanted into the gastric wall were fed with drinking water containing 3 mg/L SW for two days alternating with that containing no SW for two days until sacrificed eight weeks after tumor implantation. RESULTS: The mean tumor volume in the SW-treated group was significantly smaller than that of the control group (0.42 +/- 0.26 cm3 vs 1.60 +/- 0.36 cm3). Calculated by volume, the tumor growth was inhibited by 73.8%. Metastasis to the liver was observed in 20% and 80% of the SW-treated and control mice, while metastasis to the peritoneum was seen in 30% and 90% of SW-treated and control mice, respectively. The total number of splenic cells, and the NK cell activity both of PBL and splenic cells were all elevated. CONCLUSION: SW is effective in inhibiting tumor growth and metastasis of human gastric cancer in nude mice. Enhanced immune response, among other things, may be involved in the anti-tumor effect.

Adenocarcinoma↗
PubMed1998

[Experimental study of the effect of angiogenesis inhibitor TNP-470 on the growth and metastasis of gastric cancer in vivo].

OBJECTIVE: To study the effect of angiogenesis inhibitor TNP-470 on the growth and metastasis of gastric cancer in vivo. METHODS: Metastatic model simulating human gastric cancer was established by orthotopic implantation of histologically intact human tumor tissue into gastric wall of nude mice. TNP-470 was administered s.c. at doses of 0 mg/kg, 15 mg/kg, 30 mg/kg, 60 mg/kg every other day for eight weeks. Ten weeks after implantation, the mice were sacrificed and the tumor size measured and the presence of metastasis recorded. The microvascular density was examined by immunohistochemical staining with anti-human factor VIII antibody. RESULTS: Compared to the untreated controls, growth of the orthotopically implanted tumor was significantly reduced in size in mice treated with TNP-470 with an inhibition rate of 59.9%, 77. 0% and 84.9% at the dosage of 15 mg/kg, 30 mg/kg and 60 mg/kg, respectively. Tumor metastasis to the liver and peritoneaum was also significantly inhibited in a dose-dependent manner. The microvascular density was also decreased significantly in the treated mice. CONCLUSION: Angiogenesis inhibitor TNP-470 has strong inhibitory effect both on tumor growth and metastasis of human gastric cancer in nude mice.

Animals↗
PubMed1998

[Clinical and experimental study on facial paralysis in temporal bone fracture].

To study the main prognostic factors and significance of facial nerve decompression of facial paralysis in temporal bone fracture, the main relative prognostic factors of 64 patients with facial paralysis were analyzed. Experimental model of facial paralysis was made. Expansion rate of facial nerve in facial canal opening group and non-opening group was measured and observed under electron microscope. The main factors affecting the prognosis were facial nerve decompression and selection of surgery time. Expansion rate of facial nerve in opening group was significantly higher than that of non-opening group. Injury degree of nerve fiber of non-opening group was severe. It is suggested that early facial nerve decompression is of beneficial to restoration of facial nerve function.

Adolescent↗
PubMed1998

[Clinical study on effects of zhiling decoction in treating senile vascular dementia].

OBJECTIVE: To observe clinical effects of Zhiling Decoction (ZLD) in treating senile vascular dementia. METHODS: Seventy-eight patients were randomly divided into treated group and control group. In treated group which was treated with ZLD, a self-formulated proved recipe. In control group, which was administered with Naofukang ([symbol: see text]). RESULTS: ZLD could decrease the level of serum cholesterol, serum triglyceride and plasma LPO significantly; increase the level of high density lipoprotein (HDL) and SOD in red blood cells; dilate cerebral vessels, increase cerebral blood flow. As for P300, an index to reflect intelligence, the latency of P3 was shorter and the amplitude was raised, the brain electrical activity monitoring (BEAM) was improved remarkably, the revised Nagayakawa dementia scale scoring (NDS) of patients promoted, clinical symptom was improved significantly. Total effective rate in clinical practice reached 87%. CONCLUSION: ZLD had good effects on senile vascular dementia indeed.

Aged↗
PubMed1998

[Nonlinear dynamic analysis of heart rate variability during exercise].

Nonlinear dynamic analysis was used to examine the changes of complexity of heart rate variability (HRV) under rest and exercise. Nine healthy male subjects participated in the test. Each subject had a rest in supine position for 10 min, and then exercised on a cycle ergometer (10 min at 50 W and 10 min at 100 W). The results showed that R-R interval and its standard deviation reduced, and at the same time the values of nonlinear dynamics indices (complexity, entropy, correlation dimension, capacity dimension) also decreased during exercise. Moreover, at 100W work load the decrease of these indices was greater than that of 50W. It shows that physical exercise may reduce the complexity of HRV, and nonlinear dynamic indices could be used in distinguishing the complexity of heart rate variability under different physiological conditions.

Adult↗
PubMed1998

[HPLC determination of two flavonoids in pollen Typhae (puhuang) and its different processed products].

OBJECTIVE: To study the changes of chemical constituents in Pollen Typhae(Puhuang) after processing. METHOD: The contents of two flavonoids, typhaneoside(I) and isorhamnetin-3-O-neohesperidoside(II), in Pollen Typhae (Puhuang) and its different processed products were determined by HPLC. RESULT: Compared with the crude drug, the contents of I and II decreased by 40.22% and 49.87% respectively in the stir-fried product. I and II were not detected in the carbonized product. CONCLUSION: The decrease of contents of I and II after processing shows that the chemical constituents in Pollen Typhae (Puhuang) have changed after processing.

Chromatography, High Pressure Liquid↗
PubMed1998

[The reason and management of intraoperative femur fracture during hip arthroplasty].

OBJECTIVE: To study the pathogenesis, treatment and prevention of intraoperative femur fracture. METHODS: Intraoperative femur fracture occurred in 25(2.6%) of 945 hip arthroplasties performed from 1972 to 1996. 142(5.6%) occurred in revision arthroplasties, 12 (2.4%) 493 primary arthroplasties (2.4%), and 5(1.3%) in 310 semi-arthroplasties. RESULTS: The causes of these fractures included osteoporosis, iatrogenic, congenital alteration of bony anatomy, and inadequate soft tissue release prior to hip dislocation during revision of hip surgery. Femoral fractures can be prevented by preoperative templating of rontgenograms containing markers to measure magnification; routine overdrawing of the femoral canal when implanting long-stemmed prostheses; and a more extensive release of the external rotators and other scar tissue performed prior to dislocation. Any structures preventing free rotation of the femur should also be considered for the release. CONCLUSIONS: We recommend that intraoperative roentgenograms be made whenever preparation of the femoral canal or impacting of the prosthesis is more difficult or when resistance is suddenly lost during implication of implant. When diagnosed intraoperatively, it should be fixed with cerclage wiring. When an incomplete fracture near the hip of the stem was discovered postoperatively and the posterior part of the femoral cortex was intact, a spica cast was applied. For a complete fracture at the tip of stem, we recommend open reduction and internal fixation.

Adult↗
PubMed1998

[Cloning and secretory expression of staphylokinase in Streptomyces lividans].

OBJECTIVE: Construct a recombinant Streptomyces strain by which staphylokinase can be secretory expressed. METHODS: With the total DNA extracted from strains of Staphylococcus aureus isolated in clinic as template DNA, one 730 bp DNA fragment including secretory signal peptide sequence and structure gene of staphylokinase was amplified by PCR. After cloning into plasmid pUC19 and sequencing, this fragment was confirmed to have the same nucleotide sequence as that of staphylokinase gene reported before. Then the fragment was inserted into Streptomyces plasmid pIJ459 following strong promoter. Recombinant plasmid pIJ459SAK was transformed into S. lividans TK54. RESULTS: The 72 hours culture supernatant of the secretory-type genetic engineering strain that harbored pIJ459SAK was analyzed by 15% SDS-PAGE. One specific protein band with molecular weight about 16,000 can be seen after staining the gel with silver nitrate. The fibrinolytic activity of Staphylokinase can be also detected in the 72 hours culture supernatant in the fibrin-plate assay. CONCLUSIONS: Staphylokinase can be successfully secreted into fermentation culture by the recombinant Streptomyces strain.

Cloning, Molecular↗
PubMed1998

[The diagnostic significance of "contraction bands" of striated muscle in forensic pathology].

The contraction bands of cardiac and skeletal muscle probes were studied. They were taken from autopsy cases with different death causes. The morphologic characteristics of the contraction bands that were closely related to diagnosis were carefully observed. It was found that the morphological patterns of the contraction bands were various and some were regularly seen for the death with certain causes. The forensic significance of the contraction bands was then discussed and it was suggested that the morphology of contraction bands of the striated muscle correlate to the type and structure of tissues as well as to the property of injuries.

Animals↗
PubMed1998

[The degeneration and regeneration of skeletal muscle after tenotomy].

In order to investigate the degeneration and regeneration of skeletal muscle fiber after tenotomy, the tenotomy were carried out on gastrocnemius muscles in 15 adult BALB/C mice. The tenotomized muscles were removed on 1, 2 and 4 weeks postoperatively. Specimens were processed for histological study with light microscope and TEM, and skeletal muscle specific protein expression analysis with myoactin (MA) and myoglobin (MG) immunohistochemical staining. The results showed that the regenerating muscle cells and the degenerating muscle fibre coexisted in tenotomized muscle. The internal structure and histochemical pattern of muscle fiber changed after tenotomy. The regenerating muscle cells fused with degenerating fibres.

Actins↗
PubMed1998

[An experimental study of expediting the early attachment of human gingival epithelial cells to titanium with laminin].

Using in vitro culture model, the attachment of human gingival epithelial cells to laminin-coated pure titanium was studied. The average numbers of attached cells on different surface of titanium with or without laminin were calculated under catoptric fluorescent microscope and were statistically analyzed with factorial design. The results showed that Laminin could expedite the early attachment of human gingival epithelial cells to titanium.

Cell Adhesion↗
PubMed1998

[Study on the NIR-Raman spectra and NIR-SERS spectra of amsacrine].

The near infrared surface-enhanced Raman spectra (NIR-SERS) of amsacrine,an anticancer agent, on silver collids were recored with high quality. The NIR-SERS enhancement factor is up to 10(4) magnitude. In comparison with the near infrared Raman (NIR-Raman) spectra of solid amsacrine, more information of vibrational structures of amsacrine molecules at low concentration and almost in its practical application envi ronment, can be given by the NIR-SERS. The enhancement mechanism is associated with the adsorption of acridyl ring and sulfonyl on silver surface.

Amsacrine↗
PubMed1998

[Some physical-chemical properties of the colloid of bentonite in Xinjiang Tuoksun county].

The X-ray diffraction pattern, infrared spectrum, differential thermal curve, dewatering curve, cation exchange capacity and specific surface of the colloid of bentonite in China (Xinjiang Tuoksun) are presented and are compared with that of bentonites in the united states (Wyoming), New Zealand (Quarget) and French. The results indicate that particles in China are finer, crystals are better, purities are higher and capabilities of absorbing water are greater. So that it has better technology characteristic in metals.

English Abstract↗