[Application of microdialysis in pharmacokinetic and drug metabolism studies].
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Microdialysis↗
Biomedical subjects
Hui Xu
Publications and source records attributed to Hui Xu.
[Study on preparation and oral efficacy of insulin-loaded poly(lactic-co-glycolic acid) nanoparticles].
AIM: To investigate the possibility of poly(lactic-co-glycolic acid) as a carrier for the delivery of macromolecular. METHODS: Insulin-loaded poly (lactic-co-glycolic acid) nanoparticles (INS-PLGA-NPs) was prepared by a double-emulsion solvent evaporation method. The size distribution was examined by photo-correlation spectrometry. The entrapment efficiency was determined by HPLC and important factors that affected the entrapment efficiency were investigated. The loading mechanism of different size nanoparticles was assayed by radioimmunoassay (RIA). INS-PLGA-NPs release behavior in vitro was carried out under sink condition. After oral administration of the nanoparticles to alloxan-induced diabetic rats, its glucose level was determined by glucose oxidize method and the oral pharmacological bioavailability in contrast to s.c. of insulin solution was calculated according to the area over the curve. RESULTS: The INS-PLGA-NPs was prepared with poloxamer 188 as a emulsifier, the mean diameter was 149.6 nm and the polydispersity index was decreased to 0.09. While the entrapment efficiency was increased to 42.8%. Most of the insulin loaded was adsorbed on the surface of the nanoparticles. The release behavior in vitro showed an initial burst effect followed by a slower rate stage. After oral administration of 10 u.kg-1 INS-PLGA-NPs, the plasma glucose level decreased significantly after 4 h (P < 0.05), 10 h later the glucose level decreased to the lowest (52.4% +/- 10.2%, P < 0.01) and the relative pharmacological bioavailability is (10.3 +/- 0.8)%. CONCLUSION: PLGA-NPs might be used as a new oral carrier for protein drug delivery systems in the future.
Administration, Oral↗
[N2O emission from trees under different light irradiances].
This paper firstly measured in situ N2O emission from branches and leaves of sun plants (Fraxinus mandshurica, Pinus koraiensis, Alnus hirsuta) and shade tolerant plants (Tilia amurrensis) under different light irradiances in closed chamber. Light irradiance had contrast effects on N2O emission flux from sun and shade-tolerant tree species. In the test sun plants, more N2O was emitted under weak light than under strong light. The emission rates decreased with increasing irradiances, and even absorption instead of emission of N2O was detected under strong light. In contrast to sun plants, in the shade tolerant plant T. amurrensis, there was more N2O emission under strong light than under weak light, and N2O absorption from environment was detected under weak light.
Fraxinus↗
Fluorescence Quenching of Anthracene by N,N-Diethylaniline in the Sodium Dodecyl Sulfate/Benzyl Alcohol/Water System.
Photoinduced electron-transfer reaction of anthracene with N,N-diethylaniline (DEA) was studied in the SDS (sodium dodecyl sulfate)/BA (benzyl alcohol)/H(2)O system. In an oil/water microemulsion, only the excited anthracene located at the interface can be quenched by DEA. In a water/oil microemulsion, this quenching reaction occurs in the BA continuous phase. Besides being the quencher of the excited anthracene, DEA could also change the system's structure. Copyright 2001 Academic Press.
Journal Article↗
Serologic analysis of anti-porcine endogenous retroviruses immune responses in humans after ex vivo transgenic pig liver perfusion.
Improvements in xenotransplantation may significantly increase the availability of organs for human transplantation. The use of porcine organs, however, has raised concern about possible transmission of porcine endogenous retroviruses (PERV) to the recipients. The authors developed monoclonal antibodies specific to the PERV Gag viral product and show that these antibodies can detect PERV antigen under a variety of assay conditions, including enzyme linked immunosorbent assay (ELISA), Western blot, and immunofluorescence staining methods. Two patients in fulminant hepatic failure were treated by extracorporeal perfusion using transgenic porcine livers before receiving orthotopic liver transplants. Despite the use of immune suppression that allowed survival of the allograft, these patients both showed a strong immune response to the xenograft suggesting a largely intact capability to mount a humoral immune response. However, analysis of patient serum samples over a 3 to 4 year period has showed no evidence of an immune response to PERV antigens, suggesting a lack of PERV infection.
Animals↗
Determination of the moisture content of bromobutyl rubber stoppers as a function of processing: implications for the stability of lyophilized products.
The purpose of the present study is to apply and contrast several analytical techniques to understand the change in moisture content of 20 mm diameter bromobutyl rubber stoppers as a function of typical stopper processing conditions. Three separate methods were examined and Karl-Fischer titration and techniques based on capacitance measurements at a thin-film sensor were found to provide comparable results. Stopper moisture levels were examined in stoppers: (i) as received from the manufacturer, (ii) following steam sterilization, (iii) as a function of various drying cycles, and (iv) during simulated hold conditions prior to use. Finally, the transfer of moisture from stopper to an actual product is examined on storage and general agreement observed between stopper drying conditions and cake moisture levels.
Elastomers↗