In vitro refolding process of bovine allergen β-lactoglobulin by Multispectroscopic method / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To characterize the relationship between the refolding process of recombinant bovine β-lactoglobulin and its immunoreactivity for clinical purposes. To establish a spectral method which examine the extent of recombinant allergen renaturation.</p><p><b>METHODS</b>The refolding process of recombinant bovine β-lactoglobulin was investigated by using circular dichroism, fluorescence and synchronous fluorescence spectra. IgE-binding capacity of recombinant protein was analyzed by ELISA. In addition, bioinformatic methods were used to explain the spectral characteristics and analyze the relationship between the conformational changes and the immunoreactivity of the protein during renaturation in vitro.</p><p><b>RESULTS</b>Renaturation of recombinant bovine β-lactoglobulin resulted in a more compact structure resembling the natural counterpart with stronger IgE-binding capacity.</p><p><b>CONCLUSION</b>The degree of protein renaturation correlated with the IgE-binding capacity of the protein. Results from this study may be of help for food allergy therapy and development of vaccination in the future.</p>

Regulation of haptoglobin expression in a human keratinocyte cell line HaCaT by inflammatory cytokines and dexamethasone / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Haptoglobin (Hp) is one of the acute-phase proteins. Recent studies have demonstrated that Hp exerts immunoregulatory and anti-inflammatory actions and may be one of the inhibitory factors of immune reactions in the skin. In this study we investigated the regulation of Hp expression in a human keratinocyte cell line HaCaT by various cytokines and glucocorticoid.</p><p><b>METHODS</b>HaCaT cells were cultured with IL-6 (50 ng/ml), TNF-alpha (20 ng/ml), IFN-gamma (20 ng/ml) or IL-4 (20 ng/ml) with or without 1 micromol/L dexamethasone in 6-well plates for 12, 24 and 48 hours. Both the cells and the supernatants were collected to detect the changes of Hp expression by reverse-transcription PCR, ELISA and immunohistochemistry.</p><p><b>RESULTS</b>The results showed that Hp expression were elevated at both the mRNA and protein level by the combination of IL-6, TNF-alpha or IL-4 with dexamethasone, whereas the three cytokines alone did not upregulate the Hp expression. IFN-gamma showed no effect on the Hp expression in HaCaT cells.</p><p><b>CONCLUSIONS</b>These findings suggest that different inflammatory cytokines as well as glucocorticoid may be involved in the regulation of Hp expression in keratinocytes, and this may be one of the negative feedback mechanisms in inflammatory skin diseases.</p>

Optimization of microemulsion containing vinpocetine and its physicochemical properties / 药学学报

<p><b>AIM</b>To prepare the microemulsion of vinpocetine in order to increase solubility and its in vitro transdermal delivery by using appropriate proportion of oil, surfactant (S), cosurfactant (CoS) and water. The formulation of proportion was optimized. The physicochemical properties and the skin irritation of the microemulsion was studied.</p><p><b>METHODS</b>Pseudo-tertiary phase diagrams were prepared to obtain the concentration ratio of components of the microemulsion. Using simplex lattice method, the formulation of microemulsion was optimized and the physicochemical properties including pH, viscosity, refractive index, conductivity and particle size distribution were examined. The MTT method was applied to test the skin irritation of the microemulsion on the Hacat cell.</p><p><b>RESULTS</b>The diagrams showed that the areas of O/W microemulsion increased with the increasing ratio of surfactant to cosurfactant (S/CoS). The predicted values from simplex lattice system were close to that of the experiment. The property of optimized microemulsion showed to be stable behavior and not irritant to Hacat cell.</p><p><b>CONCLUSION</b>The drug solubility and in vitro perscutaneous permeation flux of the optimized microemulsion was improved significantly and the irritation study showed that optimized microemulsion was safe as an ideal transdermal delivery system.</p>