Diagnostic value of 64-slice spiral CT on in-stent restenosis after PCI in patients with coronary heart disease / 心血管康复医学杂志

Objective:To explore the diagnostic value of 64‐slice spiral CT for in‐stent restenosis (ISR) after percuta‐neous coronary intervention (PCI) in patients with coronary heart disease (CHD) .Methods :A total of 120 CHD patients after PCI received 64‐slice spiral CT angiography and routine coronary angiography (CAG ) respectively . Then coronary ISR was assessed .Results:With CAG as the gold standard ,sensitivity ,specificity ,positive predictive value and negative predictive value were 87.5% ,95.3% ,80.0% and 97.3% respectively for 64‐slice spiral CT cor‐onary angiography in diagnosis of ISR .Conclusion :The 64‐slice spiral CT coronary angiography possesses high sensitivity and accuracy diagnosing coronary in‐stent restenosis ,which can be used as one of noninvasive measures for postoperative follow‐up after percutaneous coronary intervention .

Purification of ovalbumin from hen egg white by high-speed counter-current aqueous two-phase chromatography / 生物工程学报

High-speed counte-recurrent chromatography (HSCCC) is a continuous liquid-liquid partition chromatography without solid matrix, which has the significant features of high resolution and high recovery. The separation of bio-macromolecule in aqueous two-phase systems (ATPs) with HSCCC is still under research, and the establishment of high-speed counter-current aqueous two-phase chromatography (HSCCC-ATP) relies on the improvement of equipment structure and optimization of operation parameters. By using a multi-column high-speed counter-current chromatograph, the separation of protein mixture and the purification of ovalbumin from hen egg white were studied. The effects of pH and PEG concentration on the partition coefficients of proteins were tested in PEG1000-phosphate ATPs, and distinct differences among partition coefficients of proteins were found at pH 9.2 and 15.0% (W/W) PEG concentration in said system. The separation of protein mixture, consisting of cytochrome C, lysozyme and myoglobin was successfully performed in 15.0% (W/W) PEG1000-17.0% (W/W) potassium phosphate ATPs at pH 9.2 with high-speed counter-current chromatograph at rotation speed of 850r/min and flow rate of 0.8mL/min, using upper phase as stationary phase. pH and PEG concentration also had distinct effects on the partition coefficients of the major protein components in hen egg white, including ovaltransferrin, ovalbumin and lysozyme. The optimal pH value and PEG concentration for the purification of ovalbumin by HSCCC-ATP were found to be 9.2 and 16.0% (W/W) respectively. Ovalbumin was successfully purified to homogeneity from the hen egg white sample in 16.0% (W/W) PEG1000-17.0% (W/W) potassium phosphate ATPs at pH 9.2 with high-speed counter-current chromatograph at rotation speed of 850r/min and flow rate of 1.8mL/min, using upper phase as stationary phase. The purification recovery of ovalbumin was around 95%.

Purification and fingerprinting development of Salvia miltiorrhiza Bunge by high-speed counter-current chromatography / 生物工程学报

In an attempt to apply high-speed counter-current chromatography HSCCC for TCM fingerprints, the separation and purification of the Chinese medicinal plant Salvia miltiorrhiza Bunge of different localities was realized using the technique. The equipments used include a HSCCC (TBE-300) of Shenzhen Tauto Biotech containing three connected preparative coils (diameter of tube = 2.6mm, total volume = 300mL) and a 20mL sample loop and a HPLC from Shimadzu of Japan with a Ultrasphere C18 column (150 x 4.6mm ID, 5microm) and a 20microL sample loop. Salvia miltiorrhiza Bunge samples from 3 locations were separated by HSCCC in a Step-wise elution program with solvent systems A (hexane:ethanol: water = 10:5.5:4.5) and B (hexane:ethanol: water = 10:7:3) at a speed of 900 r/min and a flow-rate of 2mL/min. All the 12 peak fractions were eluted within 13 hours. The contents of each component varied greatly in different samples, which confirmed previous observation that the locations and climates have a great impact on the TCM quality and also indicated a quality control system is necessary to safeguard the quality of the herb. The retention times of the 12 peak fractions from crude extracts of the samples were collected by HPLC and the absorption spectrums of the corresponding peaks were identified. The 12 components of the three crude samples were readily distinguishable and can be used as fingerprints of S. miltiorrhiza Bunge. The relative standard deviation of the HSCCC retention times was less than 3%, which satisfies the requirement of the national standard reference index. The components 7, 8 and 11 from the standards were identified to be crypototanshinone, tanshinone I and tanshinone II A respectively. This study demonstrates that if it is possible to apply HSCCC for TCM fingerprinting, especially with samples of high viscosity and highly absorptive components. The precision and the run time of fingerprinting can be further improved if larger volume and a temperature control system is used. With these and other improvements, HSCCC is expected to play an important role in TCM development.

Establishment and application of the model of islet impaired by NO free radical released from streptozotocin / 生物工程学报

For diabetes mellitus, little research has been done on the tissue-based or cell-based drug screening model, which has advantages over traditional animal diabetic model in high specificity, high screening volume, low cost and simple manipulation. Considering that the maintenance of complete islet tissue structure is the prerequisite for islet cells to perform their functions normally, an in vitro islet-based drug screening model for diabetes mellitus was established and evaluated. Pancreatic islets were isolated from 3 weeks old mice of either sex by collagenase digestion and density gradient centrifugation as prescribed by Ramanadham S. The volume of 0.1% (W/V) collagenase IV, 0.1% (W/V) Hyaluroridase and 0.1% (W/V) DNase I were 4 times, 2 times and 1 times that of the islets to be digested. And a 2 hours' cold digestion at 4 degrees C was followed by a 10 minutes' warm digestion at 37 degrees C. Under the optimized digestion condition, the islet recovery could be increased by 10%. The isolated islets could survive 6 weeks in vitro and show stable insulin secretion in the first 10 days after inoculation. The obtained islets were cultured in RPMI-1640 medium at 37 degrees C with 5% CO2. Then a diabetic model was established by selecting streptozotocin (STZ) as the evocator and nitric oxide (NO) as the responding index. After 1 day's inoculation, islets culture was treated with STZ, whose concentration ranged from 0 to 5.0 mmol/L. NO was measured by a colorimetric assay at 540nm based on the Griess reaction for 10 min with 0.1 mL Griess reagent and 0.1 mL culture supernatants. Insulin secretion was assayed by RIA methods. Due to the islets-related inoculation variations, NO release and insulin content were both expressed as a percentage of the value recorded in basal experiment which was in the only presence of Krebs culture medium. It was testified that the amount of NO released from islet itself remained steady at 30-35 mmol/L regardless of the changes of STZ concentration from 0 to 5.0 mmol/L. However the NO content in the supernatants of islets culture had close relationship with STZ concentration. This indicated that in this STZ-induced islet diabetic model, NO mainly comes from STZ when it dissolves in water. On the other hand, when STZ changed from 0 to 5.0 mmol/L, the dose-dependent relationship between NO content and insulin secretion showed that the increase of NO came along with the decrease of insulin secretion, which is an important symbol of islet function. As a kind of oxidative free radical, NO is capable of impair islet cells. Thus, NO is a reliable responding index of the model. The optimal STZ concentration in the model is finally determined to be 5.0 mmol/L, under which condition the NO content and insulin secretion is 10.81 times and 0.43 times that in the medium before STZ is added. So if anything is effective in lowering the NO content in the culture, it could protect islets cells from the oxidative attacks of NO. Finally, as an application of the model, the scavenging effect of KOSCr on NO was studied. In a series of KOSCr with different chromium content, all had shown better NO scavenging effects than KOS itself, which could give us an enlightenment of the influence of chromium ion on oligosaccharide. And 1 g/mL KOSCr with 3.519% chromium content can significantly inhibit the NO formation. This has lain a theoretic basis for the research of KOSCr bioactivity and quality control. These results suggested that the STZ-induced diabetic islet model which is impaired by NO free radical can be used effectively, fast and conveniently when screening potential diabetes drugs.

Study on bridged avidin biotin technique improving the sensitivity of phycobiliprotein immunofluorescence assay / 细胞与分子免疫学杂志

Aim To improve the sensitivity of phycobiliprotein immunofluorescence assay(PBPIFA), by introducing into bridged avidin biotin(BRAB) technique,known as BRAB-PBPIFA. Methods Using ELISA as a gold standard, effectiveness of three assays(direct PBPIFA, BRAB-PBPIFA and ELISA)were compared in simultaneous detection of standard antigen and 500 serum samples. Results BRAB improved greatly sensitivity of PBPIFA in detecting antigen of low concentration, and detection rate of weakly positive samples could increase by one times and a half. In the applying, protein-free blocking agent Tween 20 to BRAB-PBPIFA,possessed better blocking effect. Conclusion Combination of BRAB technique with PBPIFA can improve the detcctive sensitivity.

Biochemical process engineerinmg and modernization of Chinese materia medica (Ⅰ) / 中草药

Some studies corresponding modernization of Chinese materia m edica(CMM)were performed in the institute for the new technologies,materials,and facilities based on the achievements and experiences gotten in the past two dec ades.The technologies of large-scale propagation of plant cell,tissue,and organ were applied to the products of cell metabolism,biotransformation,and artificial breeding and rooting.Many new types of large-scale bioreactors were designed an d used not only for laboratory but also for manufactory.Reaction/separation inte gration technology,microwave-assisted extraction,and the other new extraction te chnologies were studied to realize high efficiency and low energy.Besides tradit ional separation and purification methods,new technologies,including extraction in reversed micelles,one step three-phase extraction on Penicillin,foam fraction ation,membrane separation,and high-speed counter-current chromatography(HSCC),we re developed.HSCCC is a kind of liquid-liquid partition chromatography without a ny solid matrix,which eliminates irreversible adsorption of samples on solid sup port in the conventional chromatographic column.It has been successfully applied to the analysis and separation of various natural products.At the same time,man y types of microsphere and microencapsules for controlled release and separation media were prepared and lots of attention was paid on drug modifying and embedd ing techniques.HSCCC was also applied as a new method to the study of CMM finger print and showed good precision and repeatability.High performance liquid chroma tography(HPLC),gas chromatography(GC),high performance capillary electrophoresis (HPCE),and mass spectrometer(MS)played a very important role in fingerprinting.C ontinuous propagation-continuous collection technological process was set for la rge-scale propagation of micro-algae in the study of marine drugs.Transgenic alg ae were cultured to prduce genetically engineered products.