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Biomedical subjects

Bin Lu

Publications and source records attributed to Bin Lu.

82 records · Page 5Linked to original sources
PubMed2002

[hEPO transfer and expression by a recombinant adeno-associated virus vector].

In order to achieve sustained human erythropoietin (hEPO) expression in vivo for the treatment of anemias, recombinant adeno-associated virus (rAAV)-mediated hEPO transfer was studied in this report. rAAV vector plasmid carrying hEPO was constructed, and rAAV vector cell line for production of rAAV was also established. By using the one helper virus-one vector cell line strategy, which we reported previously, rAAV containing the hEPO expression cassette was produced in large-scale. The results showed that the hEPO expressed effectively by rAAV-mediated hEPO transfer into cultured BHK-21 cells. Intramuscular injection of rAAV-hEPO to Balb/c mice resulted in the in vivo expression of hEPO for at least ten weeks, along with the significant elevation of the hematocrits. This report indicates the potential use of rAAV-mediated gene transfer for the treatment of various anemias.

Animals↗
PubMed2002

Bioluminescent method for detecting telomerase activity.

BACKGROUND: Telomerase is a promising biomarker in cancer diagnosis and therapy. The elongation of telomeric repeats catalyzed by telomerase is accompanied by release of six PP(i) for each TTAGGG repeat (1 pmol PP(i)/310 pg telomeric repeats). We developed a novel method to measure telomerase activity by use of an enzymatic luminometric PP(i) assay (ELIPA). METHODS: Extracts of cell lines and tissues were incubated with primer at 30 degrees C for 30 min. Released PP(i) was converted to ATP by sulfurylase, and ATP was detected by a luciferase bioluminescence system. The ELIPA results were compared with results obtained with the conventional telomeric repeat amplification (TRAP)-ELISA in 42 lung carcinoma tissues and 27 control tissues without malignancy. RESULTS: The lower detection limits of ELIPA and TRAP-ELISA were 5 and 10 cells, respectively. The within-run imprecision (CV) of ELIPA was < or =12%. When compared with TRAP-ELISA, the correlation coefficient (r) was 0.79. When we used the cutoff value from ROC analysis to distinguish malignant and nonmalignant tissues, the sensitivity and specificity of ELIPA were 83% and 96%, respectively, whereas the sensitivity and specificity of TRAP-ELISA were 71% and 96%, respectively. CONCLUSION: ELIPA is a simple and sensitive homogeneous method to quantify telomerase activity.

Adenosine Triphosphate↗
PubMed2002

[Osteogenesis of HA/TCP biphasic ceramics implanted into muscle: a long-term study].

New bone formation in long-term intramuscle implant of Ca-P biomaterial was investigated in this experiment. After implanting into dog dorsal muscle for 15 months, a thin fibrous membrane that wrapped HA/TCP implant was still observed obviously. Three types of tissues, i.e. mesenchymal tissue, bone and bone marrow, regularly distributed in different pores of implant. Nearly all the pores of implants were occupied by bone. Bone in the pores located in the central region of implant was matured lamellar bone characterized by obvious lacuna and rich bone marrow. However, bone in the peripheral pores was immature woven bone without bone marrow formation. Furthermore, mesenchymal tissues only exist in the peripheral pores and usually were connected with immature woven bone. It was demonstrated that porous HA/TCP has bone inductivity and it could induce new bone formation at non-osseous site. Well-regulated distribution of mesenchymal tissue, bone and bone marrow in the pores suggest bone morphogenesis in the implant must obey a specific space-time program.

Animals↗
PubMed2002

[The method for determination of aconitum alkaloids in Radix Aconiti Kusnezoffii].

The methods for the determination of Aconitum alkaloids in Radix Aconiti Kusnezoffii were established. Volumetric analysis with the indicator of methyl red-bromcresol green and colorimetric analysis with acid dye of bromecresol green under the wavelength of 416 nm were used for the assay of total alkaloids. Colorimetric analysis of hydroxamic acid-Fe was for the assay of total ester-diterpene type Aconitum alkaloids. Three kinds of diester-diterpene type Aconitum alkaloids (aconitine, hypaconitine and mesaconitine) were determined by HPLC method. The HPLC system consisted of C18 as the stationary phase and acetonitrile: buffer (acetic acid-triethylamine, pH 6.25) = 71:29 as the mobile phase. The wavelength was 235 nm.

Aconitine↗
PubMed2002

[Effects of image quality of intravenous three-dimensional electron beam coronary angiography].

OBJECTIVE: To identify reasons for poor image quality and nonassessability of coronary artery segments, and compare results between early and late diastolic triggering on coronary electron beam angiography (EBA). METHODS: One hundred patients referred for EBA were studied. Contrast-enhanced transaxial coronary images were acquired using electrocardiographic triggering and reconstructed three-dimensionally using volume rendering techniques. The image quality of coronary segments and image artifacts were analyzed statistically. RESULTS: Volume rendering was failed in 7 patients (7%) due to cardiac and breathing motions. Image quality was the best with the left main (LM), and worst with the left circumflex (LCX) coronary artery (P < 0.001). The image quality decreased systematically from proximal to distal within each coronary artery (P < 0.001). Forty percent R-R interval triggering on electrocardiography was better than 80% for image quality. The nonassessable segments occurred in 3% of LM, 2%, 8%, and 5% of proximal, 24%, 22%, and 12% of mid, 64%, 45%, and 20% of distal segments of the left anterior descending (LAD), LCX, and right coronary artery (RCA), respectively (P < 0.05). CONCLUSIONS: The major limitations of coronary EBA are in suboptimal spatial resolution and image artifacts. The image quality could be improved by using optimal electrocardiographic triggering.

Aged↗
PubMed2001

Influence of Surfactant Concentration and Counterion to Surfactant Ratio on Rheology of Wormlike Micelles.

The influence of concentration on rheological properties, including shear viscosity, shear instability, transient stress start-up and relaxation, apparent extensional viscosity, viscoelastic behavior, and microstructure by cryo-TEM, were studied with surfactant Ethoquad O/12, commercialized oleyl methyl bishydroxyethyl chloride, with counterion sodium salicylate. Counterion to surfactant molar ratios, xi, were 1.0 and 2.5. Concentrations for the xi=1 series are 5 mM/5 mM, 10 mM/10 mM, 50 mM/50 mM, 100 mM/100 mM, and 200 mM/200 mM (surfactant/counterion); those for the xi=2.5 series are 5 mM/12.5 mM, 10 mM/25 mM, 50 mM/125 mM, 100 mM/250 mM, and 200 mM/500 mM. The experimental results showed complicated rheological behavior with concentration changes. Shear viscosity decreases with increases in concentration for the xi=1 series. At xi=2.5 apparent viscosity increases with concentration above 10 mM. Viscoelasticity of the solutions also decreases with increases in surfactant concentration. At high concentration, a high shear rate is needed to induce viscoelasticity. A high extensional rate induces supermicellar structures. Gelation was observed during shear for the 100 mM/250 mM and 200 mM/500 mM solution in the cone-and-plate geometry. Cryo-TEM results revealed that all of the solutions examined had wormlike network micelle microstructures. Copyright 2001 Academic Press.

Journal Article↗
PubMed1999

Consequence alimentary reconstruction in nutritional status after total gastrectomy for gastric cancer.

AIM:To investigate the effect of gastroenteric reconstruction on the nutritional status of patients with gastric cancer after total gastrectomy.METHODS: From 1989-1994, nutritional status was studied in 24 patients, including 12 patients with the gastric reservoir and pyloric sphincter reconstruction (GRPS), 7 with Braun's esophago-jejunostomy (EJ) and 5 with Lawrance's Roux en Y reconstruction (RY).The ability of these patients to ingest and absorb the amount of nutrients was examined and compared, and metabolic balance test was performed to compare the efficiency of those patients to accumulate and use the absorbed nutrients.RESULTS:In the controlled hospital situation, the amount of food ingested by all the patients was greater than that required for maintenance of ideal body weight. In direct contrast, food intake in most patients with EJ or RY reconstruction significantly decreased when the patients returned home and that in EJ patients it was the lowest. The overgrowth of anaerobic bacteria was found in the jejunum in the patients with EJ and RY, due mainly to food stasis in the duodenum or in the Roux limb,caused by the operative procedure itself. In patients with GRPS,because of restoring of the alimentary continuity according to the normal digestive physiologic characters, all the nutritional parameters could fall in the normal range.CONCLUSION:The most common mechanism responsible for postoperative malnutrition was inadequate food intake. Having solved the problem of alkaline reflux esophagitis, it is imperative to preserve the duodenal food passage to reduce malabsorption and other complications after total gastrectomy.

Journal Article↗
PubMedDate not supplied

Image quality of three-dimensional electron beam coronary angiography.

PURPOSE: This study identifies reasons for poor image quality and nonassessability of coronary artery segments and compares results between early and late diastolic triggering on coronary electron beam angiography (EBA). METHOD: One hundred patients referred for EBA were studied. Contrast-enhanced transaxial coronary images were acquired using electrocardiographic (ECG) triggering and reconstructed three dimensionally using volume-rendering techniques. The image quality of coronary segments and image artifacts were analyzed statistically. RESULTS: Volume rendering failed in seven patients (7%) owing to cardiac and breathing motions. Image quality was the best with the left main (LM) and worst with the left circumflex (LCX) coronary arteries (p < 0.001). The image quality decreased systematically from proximal to distal within each coronary artery (p < 0.001). Forty percent R-R interval triggering on ECG was better than 80% for image quality. The nonassessable segments occurred in 3% of LM, 2, 8, and 5% of proximal, 24, 22, and 12% of mid, and 64, 45, and 20% of distal segments of the left anterior descending, LCX, and right coronary arteries, respectively (p < 0.05). CONCLUSION: The major limitations of coronary EBA were suboptimal spatial resolution and image artifacts. The image quality could be improved by using optimal ECG triggering.

Aged↗
PubMedDate not supplied

Ability of calibration phantom to reduce the interscan variability in electron beam computed tomography.

OBJECTIVE: To test the hypothesis that a calibration phantom would improve interpatient and interscan variability in coronary artery calcium (CAC) studies. METHODS: We scanned 144 patients twice with or without the calibration phantom and then scanned 93 patients with a single calcific lesion twice and, finally, scanned a cork heart with calcific foci. RESULTS: There were no linear correlations in computed tomography Hounsfield unit (CT HU) and CT HU interscan variation between blood pool and phantom plugs at any slice level in patient groups (p > 0.05). The CT HU interscan variation in phantom plugs (2.11 HU) was less than that of the blood pool (3.47 HU; p < 0.05) and CAC lesion (20.39; p < 0.001). Comparing images with and without a calibration phantom, there was a significant decrease in CT HU as well as an increase in noise and peak values in patient studies and the cork phantom study. CONCLUSION: The CT HU attenuation variations of the interpatient and interscan blood pool, calibration phantom plug, and cork coronary arteries were not parallel. Therefore, the ability to adjust the CT HU variation of calcific lesions by a calibration phantom is problematic and may worsen the problem.

Artifacts↗