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Biomedical subjects

H Zou

Publications and source records attributed to H Zou.

At least 91 records · Page 5Linked to original sources
PubMed1999

[Effects of temperature on the migration time window of micellar electrokinetic capillary chromatography].

The effects of capillary temperature, the nature and concentration of buffer on the migration time window of micellar electrokinetic capillary chromatography are investigated through three parameters including electroosmotic mobility (micro eo), the electrophoretic mobility micelle (micro ep,mc) and mobility ratio (Rm,mc). (micro eo) and (micro ep,mc) increase linearly as capillary temperature increases. Change in the viscosity of the running buffer is the main factor in the temperature effect. It is proved theoretically that the local viscosity at the capillary wall is different from the bulk viscosity. The increasing rate of micro eo with temperature is different from that of micro ep,mc. The migration time window can be expanded by lowering capillary temperature. Although the expanding is limited, this method can be very easily achieved on a commercial apparatus. A uniform formula has been derived to describe the relationships between micro eo, micro ep,mc and the concentration of buffer. For Tris and borate buffer, both micro eo and micro ep,mc decrease with increasing buffer concentration, but the decreasing rate is limited. Thus the effect on the migration time window is not significant. For phosphate buffer, the effects on micro eo and micro ep,mc are different in different concentration ranges. micro eo decreases rapidly in low concentration range but decreases slowly in high concentration range with increasing buffer concentration. micro ep,mc decreases in low concentration range but increases in high concentration range with increasing buffer concentration. The migration time window can be significantly expanded by increasing the concentration of phosphate buffer.

English Abstract↗
PubMed1999

[Treatment of chronic prostatitis with computerized herbal drug penetrator].

A computerized herbal drug penetrator for chronic prostatitis was designed and developed on the basis of a combination of the authors' clinical practice with modern Traditional Chinese Medicinal theories. The device has integrated many hi-techs of current engineering science. It works by applying special herbal medicine, electro-magnetic effects, thermal moxibustion, perfusion and pulsated massage with water-capsule. The result of using this technique in the treatment of 100 cases has demonstrated its satisfying effectiveness.

Acupuncture Therapy↗
PubMed1999

[Study on heparin-like materials--sulfonization and blood compatibility of PVA, PET and PEU].

In this paper, physical mechanical properties and changes of chemical structures of some heparin-like biomaterials were studied before and after sulfonization of PVA, PET and PEU. The results showed that these materials were easy to be sulfonized, but it was necessary to keep actual sulfonization degree for their mechanical properties. Platelets adhesion experiments demonstrated that the materials adsorbed very few and showed heparin-like anti-coagulant property after sulfonization.

Animals↗
PubMed1999

[Hydrophobic membrane chromatography for fast purification of biological macromolecules].

Cellulose membrane bonded with four commonly used hydrophobic groups, octyl, butyl, phenyl and polyethylene glycol was first investigated for their binding and purification characteristics of protein and enzyme with octyl- and phenyl-Sepharose CL-4 B as controls. Hydrophobic membranes bound BSA effectively by hydrophobic interaction in high salt solution. Their binding capacities were not notably affected by significantly increasing the flow mass rate or decreasing the mass concentration of protein solution, but were much lower than those of octyl- and phenyl-Sepharose CL-4B. 11.8 fold of purification with an approximately 100% recovery of bovine liver catalase was achieved by step gradient elution on the phenyl cellulose membrane cartridge in a single step in only ten mins or a little more. Increase of the flow mass rate had no effect on the purification of catalase, however, the processing time was shortened greatly. Hydrophobic membrane chromatography here reported exibits a potential of fast processing of the protein solution in large volume with low mass concentration of the target protein, such as genetic engineering culture solution.

Animals↗
PubMed1999

[Use of diagnostic ultrasound of sinus in the paranasal sinus disease].

OBJECTIVE: To utilize the diagnostic A ultrasound of sinuses in the diagnosis of paranasal sinus disease. METHOD: Through history enquirement, careful clinical otorhinolaryngological examination, X-ray examination of paranasal sinus, CT, maxillary sinus puncture and examination of the diagnostic ultrasound of sinus, we observed 115 patients with paranasal sinus disease and compared them with 22 normal people who were in control group. RESULTS: In normal people, the according rate between ultrasound examination and clinicaly diagnostic methods, include history enquirement, otorhinolaryngological examination, X-ray examination, CT and maxillary puncture, is 100%. And in the group of patients with paranasal disease, the according rate is 62.5%-92%. CONCLUSION: The diagnostic A ultrasound of sinus has high accuracy, the control is easy, the cost is relatively lower, it can be used repeatedly and do no harm to the patient's health. It is a good method and assistant technigue in the diagnosis of frontal and maxillary sinus disease.

Adolescent↗
PubMed1998

Bid, a Bcl2 interacting protein, mediates cytochrome c release from mitochondria in response to activation of cell surface death receptors.

We report here the purification of a cytosolic protein that induces cytochrome c release from mitochondria in response to caspase-8, the apical caspase activated by cell surface death receptors such as Fas and TNF. Peptide mass fingerprinting identified this protein as Bid, a BH3 domain-containing protein known to interact with both Bcl2 and Bax. Caspase-8 cleaves Bid, and the COOH-terminal part translocates to mitochondria where it triggers cytochrome c release. Immunodepletion of Bid from cell extracts eliminated the cytochrome c releasing activity. The cytochrome c releasing activity of Bid was antagonized by Bcl2. A mutation at the BH3 domain diminished its cytochrome c releasing activity. Bid, therefore, relays an apoptotic signal from the cell surface to mitochondria.

Amino Acid Sequence↗
PubMed1998

The 40-kDa subunit of DNA fragmentation factor induces DNA fragmentation and chromatin condensation during apoptosis.

We report here the reconstitution of a pathway that leads to the apoptotic changes in nuclei by using recombinant DNA fragmentation factor (DFF), a heterodimeric protein of 40 and 45 kDa. Coexpression of DFF40 and DFF45 is required to generate recombinant DFF, which becomes activated when DFF45 is cleaved by caspase-3. The cleaved fragments of DFF45 dissociate from the DFF40, the active component of DFF. Purified DFF40 exhibited an intrinsic DNase activity that was markedly stimulated by chromatin-associated proteins histone H1 and high mobility group proteins. DFF40 also triggered chromatin condensation when incubated with nuclei. These data suggest that DFF40 is sufficient to trigger both DNA fragmentation and chromatin condensation during apoptosis.

Amino Acid Sequence↗
PubMed1998

Expression of a constitutively active type I BMP receptor using a retroviral vector promotes the development of adrenergic cells in neural crest cultures.

Previous work has demonstrated that the bone morphogenetic proteins (BMP)-2, BMP-4, and BMP-7 can promote the development of tyrosine hydroxylase (TH)-positive and catecholamine-positive cells in quail trunk neural crest cultures. In the present work, we showed that mRNA for the type I bone morphogenetic protein receptor IA (BMPR-IA) was present in neural crest cells grown in the absence or presence of BMP-4. We have used a replication-competent avian retrovirus to express a constitutively active form of BMPR-IA in neural crest cells in culture. Cultures grown in the absence of BMP-4 and infected with retrovirus containing a construct encoding this activated BMPR-IA developed five times more TH-immunoreactive and catecholamine-positive cells than uninfected control cultures or cultures infected with virus bearing the wild-type BMPR-IA cDNA. The number of TH-positive cells which developed was dependent on the concentration of virus bearing the activated receptor cDNA used in the experiments. Most TH-positive cells which developed also contained viral p19 protein. Total cell number was not affected by infection with the virus containing the activated receptor construct. The effect of the activated receptor was phenotype-specific since infection with the virus bearing the activated receptor cDNA did not alter the number or morphology of microtubule-associated protein (MAP)2-immunoreactive cells, which are distinct from the TH-positive cell population. These findings are consistent with the observation that MAP2-positive cells are not affected by the presence of BMP-4. Taken together, these results suggest that activity of BMPR-IA is an important element in promoting the development of the adrenergic phenotype in neural crest cultures.

Adrenergic Fibers↗
PubMed1998

Quantitative study of competitive binding of drugs to protein by microdialysis/high-performance liquid chromatography.

A displacement equation describing competitive binding of drugs to protein in solution is derived and examined with four nonsteroidal anti-inflammatory drugs and human serum albumin as model drugs and protein, respectively. Microdialysis/high-performance liquid chromatography was adopted to determine simultaneously the unbound solute and displacing agent in drug-protein solutions. The method is able to locate the binding site and determine affinity constants even up to 10(7) L/mol accurately. A comparison of association constants determined by this method and from capacity factors on HSA-CSP is given.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1998

Transforming growth factor-beta, endothelin-1, and c-fos expression in necrotizing/crescentic IgA glomerulonephritis.

BACKGROUND: Among our cases of IgA glomerulonephritis (IgAGN), 10% show necrotizing/extracapillary lesions involving a small percentage of glomeruli and associated with a certain degree of inflammation in absence of glomerular and interstitial scarring. In our experience, also in repeat biopsies, these cases of IgAGN have a worse prognosis probably because necrotizing/extracapillary lesions can repeat and accumulate, leading to the progression of damage. As it is well known that transforming growth factor-beta (TGF-beta) and endothelin-1 (ET-1) are key-factors in the progression of glomerulonephritis, aim of the study was to examine their expression in renal biopsies of primary IgAGN with necrotizing/crescentic lesions in complete absence of interstitial fibrosis. To obtain information about the mitogenic effect of ET-1, the expression of c-fos, whose upregulation by ET-1 has been established in culture, was also studied. METHODS: Eighteen renal biopsies of patients with necrotizing/crescentic IgAGN were examined by immunohistochemistry with antibodies against TGF-beta, ET-1 and c-fos. The results were compared with those obtained on 22 cases of IgAGN characterized only by pure mesangial proliferation and 25 IgAGN biopsies with advanced, not active, glomerulointerstitial lesions. RESULTS: In necrotizing/crescentic IgAGN glomerular TGF-beta appeared more positive than in cases characterized only by pure mesangial proliferation and was especially expressed on cellular crescents. In the interstitium, TGF-beta, ET-1 and c-fos were expressed by infiltrating leukocytes, tubules, and small vessels. This positivity, although similar as localization, was less diffuse than in biopsies with advanced interstitial damage, but significantly greater than in cases with pure mesangial proliferation. CONCLUSIONS: Positivity of TGF-beta on cellular crescents is similar to that observed from other authors in different types of necrotizing/crescentic human glomerulonephritis and supports our hypothesis that this is a peculiar type of IgAGN. Moreover, interstitial expression of TGF-beta, ET-1 and c-fos in biopsies with glomerular active lesions but complete absence of interstitial fibrosis may potentially represent a signal of activation of mechanisms that induce and amplify the damage leading to further progression of the disease.

Adolescent↗
PubMed1998

Preparation and blood compatibility of new silica-chitosan hybrid biomaterials.

The development of new materials containing both organic and inorganic structures is of great interest with respect to achievement of obtaining the special properties, and the solgel process has provided new opportunities for making such materials. In this paper, new silica-chitosan hybrid biomaterials were produced by this technique, using biopolymer chitosan and its heparin-like derivative as the organic species to be incorporated into the silicon alkoxide (TEOS) based network. All the samples made were in form of thin, flexible films with optical clarity. Microphase separated structure was observed in the hybrid surface, with hydrophobic SiO2 and hydrophilic chitosan interleaved. These hybrid materials displayed good blood compatibility in comparison with their single component systems.

Biocompatible Materials↗
PubMed1998

Fast assay and mini-purification of protein by high performance membrane affinity chromatography.

Several affinity ligands of protein A, human immunoglobulin G, iminodiacetate (IDA)-Cu2+, and cibacron blue F3GA were coupled to GMA-modified cellulose membrane matrices. We prepared the columns based on the membrane supports in high performance membrane affinity chromatography (HPMAC). Next we evaluated nonspecific adsorption of proteins on the membrane media. The rapid assay of proteins on the affinity columns based on membrane supports was achieved. It was observed that the affinity columns based on membrane supports provided good reproducibility, high separation efficiency, and low pressure drop of the column. The columns with the membrane media could also be used for purification of proteins.

Adsorption↗
PubMed1998

[Retention behaviours of neutral solutes in reversed-phase capillary electrochromatography].

In this paper, retention behaviours of neutral solutes in reversed-phase capillary electrochromatography (RP-CEC) was studied separately with methanol, acetonitrile, isopropanol and tetrahydrofuran as organic modifiers. It was found that at certain concentration, the order of mu eo was in accordance with the epsilon/eta value of the organic modifier in the mobile phase. In addition, the relationship between mu eo and phi was relevant to the property of the organic modifier. With more organic modifier in the mobile phase, mu eo increased in methanol-water and acetonitrile-water systems; it changed little in tetrahydrofuran-water system and decreased slightly in isopropanol-water system. Linear relationship between capacity factors of neutral solutes and the volume fraction of the organic modifier in the mobile phase was obtained in CEC, and was similar to that in RP-HPLC. With the same column under the same conditions, it was found that the capacity factors of solutes in RP-CEC and RP-HPLC were almost the same, which means that the retention mechanisms of neutral solutes in these two modes might be quite similar.

Chromatography, High Pressure Liquid↗
PubMed1998

[Determination of HIgG in Human plasma by high performance membrane affinity chromatography(HPMAC)].

An assay technique for determination of Human IgG in human plasma has been developed by utilizing Protein A bound to the modified cellulose matrices based on the strong affinity between protein A and Fc region of IgG. The pH values of loading buffer and elution buffer were 7.0 and 2.3 respectively. The cartridge used was 20 mm x 4 mm i.d. and detection was carried out with a UV monitor at 280 nm. The non-specific adsorption of two kinds of media has been studied. The media without hexyldiamine arm gives very low non-specific adsorption BSA. The calibration curve showed a good linearity (correlation coefficient > 0.9992) in the injected amount range of 9-70 micrograms for HIgG. The total time for separation and determination was within 5 min and the total time of rapid assay was within 30 s. Relative standard deviations of peak areas were 1.5% (n = 5) and 3.6% (n = 3) for HIgG in standard solution and human plasma respectively.

Chromatography, Affinity↗
PubMed1998

[Determination of Ondansetron in injection by high performance capillary zone electrophoresis].

Ondansetron is a kind of drug which is used for the treatment of nausea and vomiting induced by cytotoxic chemotherapy and radiotherapy. In this paper, a method to determine Ondansetron in injection by high performance capillary zone electrophoresis is discussed. The injection was directly introduced into the capillary employing 40 mmol/L phosphate at pH 4.03 as buffer. The capillary used was 75 microns in i.d. and 47 cm in length. UV detection was set at 254 nm. The calibration curve showed good linearity. The recovery of Ondansetron ranged from 95%-98% with a coefficient of variation of 1.05%(n = 4). This method is simple, rapid and reliable.

Antiemetics↗
PubMed1998

[The property of protein A affinity membrane cartridge and purification of IgG from human plasma].

A new protein A affinity membrane based on composite matrix formed by covalent cross-linking of the glycidyl methylacrylate to softwood cellulose fiber was developed. The study focused on the physical properties and adsorption capacity of the affinity membrane cartridge. The results showed that the relationship between flow-rate and backpressure was linear. When flow-rate was 3 mL/min, backpressure attained 160 kPa. The effects of IgG mass concentration and sampling flow-rate on the binding capacity by protein A cartridge were studied for the optimum purification of IgG. A 21.7 mg/g dry matrix of maximum dynamic binding capacity for IgG was obtained by dynamic adsorption. The cartridge was loaded with human plasma to test its ability to fractionate IgG. The IgG purified from human plasma was analysed by capillary zone electrophoresis (CZE). The results showed that the protein A affinity membrane cartridge had high selectivity for IgG from human plasma. The purity of IgG from human plasma purified by the immobilized protein A membrane cartridge was over 98%. The fast-flow property of the membrane cartridge made from such a matrix and its simplicity in operation provide effective means for purifying immunoglobulins on a relatively large scale.

Chromatography, Affinity↗
PubMed1998

[Experimental study on the biocompatibility and toxicology of interface between hydroxyapatite coating and bone].

According to "The standards for biological evaluation of bio-materials and bio-products abbreviated to STANDARDS" newly set by the Ministry of Health, PRC, 5 observation indexes were selected to evaluate systematically the biocompatibility and toxicology of China-made hydroxyapatite, which is clinicall used. The results revealed no effects of allergy, mutation and hemoclasis reaction except mild cytotoxicity. These indicate that the China-made hydroxyapatite meets the demand of STANDADS and thus may be clinically with safety.

Coated Materials, Biocompatible↗