Simulation Analysis of Occupancy Rates of Baicalein， Quercetin and Galangin on Target Sites of Xanthine Oxidase / 中国实验方剂学杂志

Objective:To simulate the occupancy rates of baicalein， quercetin and galangin on the target sites of xanthine oxidase <italic>in vivo</italic>. Method:In this experiment， the half inhibitory concentration （IC₅₀） of febuxostat， baicalein， quercetin and galangin against xanthine oxidase were determined by <italic>in vitro</italic> enzymatic reaction. Binding free energy was predicted by molecular docking technology and their association rate constant （k_on） and dissociation rate constant （k_off） were determined by surface plasmon resonance technology. Based on measured binding kinetic parameters （k_on and k_off） and extracted pharmacokinetic data， the target occupancy model <italic>in vivo</italic> was established. Result:The IC₅₀values of febuxostat， baicalein， quercetin and galangin were 0.002 7， 1.63， 0.38， 1.59 µmol·L^-1， respectively. The IC₅₀ of febuxostat was very close to that reported in the literature. The predicted curve of target occupancy rate <italic>in vivo</italic> of febuxostat was consistent with its duration of clinical efficacy. When single intragastric administration of long-circulating liposomes of quercetin with dose of 100 mg·kg^-1 in rats， the time of target occupancy rate >70% <italic>in vivo</italic> lasted for about 3.9 h. When rats were orally administered baicalein and galangin with dose of 200 mg·kg^-1， the time of target occupancy rate >50% <italic>in vivo </italic>lasted for about 10 h and 1.7 h， respectively. Conclusion:The prediction model of xanthine oxidase target occupancy constructed by drug target binding kinetics and <italic>in vivo</italic> pharmacokinetic curves can effectively evaluate the <italic>in vivo</italic> inhibitory activity of compounds against the target.

Study on drug-target binding kinetics profiles of flavonoids in Chrysanthemum morifolium and xanthine oxidase / 中国中药杂志

Based on the target occupancy mathematical model, the binding kinetic process of potential active ingredients of lowering uric acid in Chrysanthemum morifolium with xanthine oxidase(XOD) was evaluated. The potential active ingredients of lowering uric acid in Ch. morifolium were screened by UPLC-Q-Exactivems MS technology, reference substance identification and in vitro enzymatic kinetics experiments. The binding kinetic parameters of xanthine oxidase and potential inhibitor in Ch. morifolium were determined by surface plasma resonance(SPR). The verified mathematical model of the XOD target occupancy evaluated the kinetic binding process of inhibitors and xanthine oxidase in vivo. According to UPLC-Q-Exactive MS and reference substance identification, 39 potential uric acid-lowering active ingredients in Ch. morifolium extracts were identified and the inhibitory activities of 23 compounds were determined. Three potential xanthine oxidase inhibitors were screened, namely genistein, luteolin, and apigenin. whose IC_(50 )were 1.23, 1.47 and 1.59 μmol·L~(-1), respectively. And the binding rate constants(K_(on)) were 1.26×10~6, 5.23×10~5 and 6.36×10~5 mol·L~(-1)·s~(-1), respectively. The dissociation rate constants(K_(off)) were 10.93×10~(-2), 1.59×10~(-2), and 5.3×10~(-2 )s~(-1), respectively. After evaluation by different administration methods, the three selected compounds can perform rapid and sustained inhibition of xanthine oxidase in vivo under combined administration. This study comprehensively evaluated the target occupancy process of three effective components in different ways of administration in vivo by UPLC-MS, concentration-response method, SPR technology and xanthine oxidase target occupancy model, which would provide a new research idea and method for screening active ingredients in traditional Chinese medicine.

Transmastoid approach for resurfacing the superior semicircular canal dehiscence with a dumpling structure / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Superior semicircular canal dehiscence (SSCD) is gradually recognized by otologists in recent years. The patients with SSCD have a syndrome comprising a series of vestibular symptoms and hearing function disorders which can be cured by the operation. In this study, we evaluated the characteristics of patients with SSCD and determined the effectiveness of treating this syndrome by resurfacing the canal via the transmastoid approach using a dumpling structure.</p><p><b>METHODS</b>Patients with SSCD, confirmed by high-resolution computed tomography and hospitalized at Beijing Tongren Hospital between November 2009 and October 2012, were included in the study. All of the patients underwent the unilateral transmastoid approach for resurfacing the canal, and received regular follow-up after surgery. Data from preoperative medical records and postoperative follow-up were comparatively analyzed to evaluate the effect of surgery.</p><p><b>RESULTS</b>In total, 10 patients and 13 ears (three left ears, four right ears, three bilateral ears) were evaluated in the study, which included 7 men and 3 women. Different symptoms and distinctive manifestations of vestibular evoked myogenic potential were found in these patients. After surgery, 4 patients had complete resolution, 5 had partial resolution, and 1 patient, with bilateral SSCD, had aggravation. None of the patients suffered from serious complications such as sensorineural hearing loss, facial paralysis, cerebrospinal fluid leakage, or intracranial hypertension.</p><p><b>CONCLUSIONS</b>In patients with unilateral SSCD, resurfacing the canal via the transmastoid approach using a dumpling structure is an effective and safe technique. However, more consideration is needed for patients with bilateral SSCD.</p>

Analysis of multicomponent drug metabolism used in clinical pharmacy research of traditional Chinese medicine / 中国中药杂志

Multicomponent drug metabolism can be defined as a research area that, rather than pharmacokinetics and pharmacodynamics, is a concerted dynamic metabolic variation of one component in several other compounds circumstance with the interaction of transport protein and drug metabolizing enzymes, and the study of the dynamic course of multiple components must be simultaneously determined. By the use of multicomponent drug metabolism in the clinical pharmacy research of traditional Chinese medicine (TCM), it can become a useful tool with the integration of the overall dialectical method and the concrete molecular approach.

Application of multicomponent dissolution evaluation method of biopharmaceutics classification system of Chinese materia medica in gegen qinlian tablets / 中国中药杂志

The study is a paticular embodiment of Chinese patent medicine based on biopharmaceutics classification system of Chinese materia medica (CMMBCS) , focusing on assessment of synchronization issues of dissolution that may affect the timing of the multicomponent absorption. The accumulative dissolution percentages of nine components in Gengen Qinlian tablets in different dissolution solvents and times were determined by HPLC. The dissolution curve was drew and its similarity was evaluated by similarity factors (f2) and cluster method. Results in this experiment showed that the components that peak 7 and peak 8 (baicalin) represented had poor similarity with the reference peak 2 (puerarin). Their similarity factors were both 43 in water dissolution media and 31 and 45 in pH 7.4 dissolution media, respectively. Components that peaks represented had better similarity with the reference peak 2 (puerarin) in other medium. It illustrated that components that peak 3,4,5,6 (berberine) represented had fully synchronous dissolution characteristics with the reference peak 2 (puerarin), components peak 1 and 9 represented had nearly fully synchronous dissolution characteristics with the reference peak 2 (puerarin), while components that peak 7 and 8 (baicalin) represented had no synchronous dissolution characteristics with the reference peak 2 (puerarin).

Impacts of multicomponent environment on solubility of puerarin in biopharmaceutics classification system of Chinese materia medica / 中国中药杂志

To illustrate the solubility involved in biopharmaceutics classification system of Chinese materia medica (CMMBCS) , the influences of artificial multicomponent environment on solubility were investigated in this study. Mathematical model was built to describe the variation trend of their influence on the solubility of puerarin. Carried out with progressive levels, single component environment: baicalin, berberine and glycyrrhizic acid; double-component environment: baicalin and glycyrrhizic acid, baicalin and berberine and glycyrrhizic acid and berberine; and treble-component environment: baicalin, berberin, glycyrrhizic acid were used to describe the variation tendency of their influences on the solubility of puerarin, respectively. And then, the mathematical regression equation model was established to characterize the solubility of puerarin under multicomponent environment.

Adenovirus-mediated delivery of bcl-2 gene attenuates cisplatin-induced degeneration of cultured spiral ganglion cells / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To assess the protection against cisplatin-induced ototoxicity by adenovirus-mediated overexpression of the bcl-2 gene in cultured spiral ganglion cells (SGC).</p><p><b>METHODS</b>SGC from P3 rats were cultured in vitro and exposed to adenovirus vector carrying green fluorescent protein gene (Ad-GFP), followed by immunocytochemical analysis for expression of the neuron-specific marker Neurofilament 200 (NF200) and detection under laser scanning confocal fluorescence microscope. Then, SGC were transduced by Ad-bcl-2 and the expression of human bcl-2 protein was evaluated by Western Blot. Finally, the cultures of SGC were divided into 4 groups: the group of Ad-bcl-2 transfection followed by cisplatin treatment, the group of Ad-GFP transfection followed by cisplatin treatment, the group of cisplatin treatment only and the untreated group. Cisplatin worked for 48 hours at a concentration of 2 microg/ml. Outcome measures included survival number of SGC and longest neurite length by using ImageJ software.</p><p><b>RESULTS</b>SGC were cultured successfully in vitro and transfected by adenovirus vector safely and efficiently. By Western Blot, human bcl-2 protein was expressed in the group after exposure to Ad-bcl-2, but not in the Ad-GFP transfected SGC. Cisplatin exposure resulted in shrinking of neuritis and pyknosis of cell body, even cell death. Expression of bcl-2 in the SGC provided a significant level of protection against cisplatin-induced SGC degeneration.</p><p><b>CONCLUSIONS</b>Our results suggest that SGC can be transduced by adenovirus vector safely and efficiently in vitro. Adenovirus-mediated delivery of the bcl-2 gene attenuates cisplatin-induced SGC degeneration.</p>

Experimental study on embryonic neural stem cells transplantation into natural rat cochlea via round window / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the survival of neural stem cell (NSC) infected by recombinant adenovirus with GFP (Ad-GFP) and the expression of GFP in normal rat cochlea and their potential effect on auditory function and cochlea structures via round window transplantation.</p><p><b>METHODS</b>In comparison with the normal rats without any transplantation (Group III), normal rat cochleae were transplanted with NSC infected with Ad-GFP (Group I) or the artificial perilymph (Group II) via round windows. Auditory functions were monitored by thresholds of auditory brain stem responses (ABR); the cochlea structures were examined by HE staining; survivals of implanted NSC were determined by the expression of GFP; survivals of hair cells were accessed by whole mount preparation.</p><p><b>RESULTS</b>Neither at pre-transplantation nor at post-transplantation, there were significant differences in the click-ABR thresholds in rats between Group I and Group II (P > 0.05). There were no significant differences in these values before and after transplantation in the same rats from each group. After transplantation, the cochlea structures were normal in both Group I & Group II. Grafted NSC was visualized by the GFP expression in every turn of the cochlea in all animals of Group I. There were no significant differences in the loss of outer hair cell (OHC) among three groups. The inner hair cell (IHC) and most OHC were normal in every turns of cochleae of all groups.</p><p><b>CONCLUSIONS</b>The embryonic NSC infected with Ad-GFP could survive and express the GFP gene in normal rat cochlea after transplantation via round window, which had not obvious affection to auditory function and inner ear pathology of rat cochlea.</p>

Gene transfer into primary cultures of fetal neural stem cells by a recombinant adenovirus carrying the gene for green fluorescent protein / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>OBJECTIVE</b>To evaluate the transduction efficiency of a recombinant adenovirus carrying the gene for green fluorescent protein (Ad-GFP) into the primary cultures of fetal neural stem cells (NSCs) by the expression of GFP.</p><p><b>METHODS</b>The Ad-GFP was constructed by homologous recombination in bacteria with the AdEasy system; NSCs were isolated from rat fetal hippocampus and cultured as neurosphere suspensions. After infection with the recombinant Ad-GFP, NSCs were examined with a fluorescent microscopy and a flow cytometry for their expression of GFP.</p><p><b>RESULTS</b>After the viral infection, flow cytometry analysis revealed that the percentage of GFP-positive cells was as high as 97.05%. The infected NSCs sustained the GFP expression for above 4 weeks. After differentiated into astrocytes or neurons, they continued to express GFP efficiently.</p><p><b>CONCLUSION</b>We have successfully constructed a viral vector Ad-GFP that can efficiently infect the primary NSCs. The reporter gene was showed fully and sustained expression in the infected cells as well as their differentiated progenies.</p>