The fliL gene significantly affects the motility and sporulation abilities of Clostridioides difficile / 生物工程学报

Flagella are the main motility structure of Clostridioides difficile that affects the adhesion, colonization, and virulence of C. difficile in the human gastrointestinal tract. The FliL protein is a single transmembrane protein bound to the flagellar matrix. This study aimed to investigate the effect of the FliL encoding gene flagellar basal body-associated FliL family protein (fliL) on the phenotype of C. difficile. The fliL gene deletion mutant (ΔfliL) and its corresponding complementary strains (: : fliL) were constructed using allele-coupled exchange (ACE) and the standard molecular clone method. The differences in physiological properties such as growth profile, antibiotic sensitivity, pH resistance, motility, and spore production ability between the mutant and wild-type strains (CD630) were investigated. The ΔfliL mutant and the : : fliL complementary strain were successfully constructed. After comparing the phenotypes of strains CD630, ΔfliL, and : : fliL, the results showed that the growth rate and maximum biomass of ΔfliL mutant decreased than that of CD630. The ΔfliL mutant showed increased sensitivity to amoxicillin, ampicillin, and norfloxacin. Its sensitivity to kanamycin and tetracycline antibiotics decreased, and the antibiotic sensitivity partially returned to the level of CD630 strain in the : : fliL strain. Moreover, the motility was significantly reduced in the ΔfliL mutant. Interestingly, the motility of the : : fliL strain significantly increased even when compared to that of the CD630 strain. Furthermore, the pH tolerance of the ΔfliL mutant significantly increased or decreased at pH 5 or 9, respectively. Finally, the sporulation ability of ΔfliL mutant reduced considerably compared to the CD630 strain and recovered in the : : fliL strain. We conclude that the deletion of the fliL gene significantly reduced the swimming motility of C. difficile, suggesting that the fliL gene is essential for the motility of C. difficile. The fliL gene deletion significantly reduced spore production, cell growth rate, tolerance to different antibiotics, acidity, and alkalinity environments of C. difficile. These physiological characteristics are closely related to the survival advantage in the host intestine, which is correlated with its pathogenicity. Thus, we suggested that the function of the fliL gene is closely related to its motility, colonization, environmental tolerance, and spore production ability, which consequently affects the pathogenicity of C. difficile.

Proteomic analysis of serum exosomes derived from Crouzon syndrome patients carrying a mutant FGFR2C342Y / 中华整形外科杂志

Objective@#Reveal the global expression profile of serum exosomal proteins of Crouzon syndrome patients.@*Methods@#We isolated microvesicles from serum of Crouzon children with a C342Y mutation in FGFR2 by ultracentrifugation, which were further characterized by electron microscopy and immunoblotting. The protein profiling in normal subjects and Crouzon patients was systematically compared by iTRAQ proteomic analysis.@*Results@#The result demonstrated that microvesicles were between 30—100 nm in diameter, round shape with cup-like concavity and expressed exosomal marker tumor susceptibility gene (TSG) 101 and flotillin (Flot) 1. We identified a total number of 62 proteins, among which 22 proteins overlap with ExoCarta database and were different between the Crouzon patient and the normal subject. The Ingenuity Pathway Analysis showed that the functions of these proteins are mostly involved in Developmental Disorder, Hereditary Disorder, Skeletal and Muscular Disorders, which are all related to the clinical manifestations of Crouzon syndrome. In addition, the proteins were focused on the network of "Organismal Injury and Abnormalities, Hematological System Development and Function, Cell-To-Cell Signaling and Interaction" . The central protein FN1 was presented as the key protein in the network.@*Conclusions@#Our data demonstrated that serum exosomes harbor informative proteins and FN1 was selected as a potential candidate for its role in promoting osteoblast adhesion, proliferation and mineralization.

The diagnosis value of TNF-α ,IL-6 and NSE in cerebrospinal fluid of children with central nervous system infection / 国际检验医学杂志

Objective To explore the diagnostic value of tumor necrosis factor-alpha (TNF-α) , interleukin-6 (IL-6) and neuron enolase (NSE) in the cerebrospinal fluid of children with central nervous sys-tem infection (CNSI).Methods 54 cases of CNSI hospitalized children ,admitted in the hospital from October 2015 to January 2017 ,were enrolled in the study and divided into viral meningitis group (30 cases) and suppu-rative meningitis group (24 cases).Another 20 cases who underwent cerebrospinal fluid examination and other related examinations were enrolled in the study as the control group.The levels of three biomarkers TNF-α , IL-6 and NSE in cerebrospinal fluid of three groups were detected by enzyme linked immunosorbent assay (ELISA).Results The levels of TNF-α ,IL-6 and NSE in purulent meningitis group were the hightest ,and the levels of these three factors in viral meningitis group were highter than the control group ,and the differ-ence was statistically significant in three groups (P＜0.05).But there were a lot of data overlaps.There was no significant difference in the levels of TNF-α ,IL-6 and NSE between the brain group and the control group (P＞0.05).Conclusion The detection of TNF-α ,IL-6 and NSE in cerebrospinal fluid has a certain clinical val-ue for the diagnosis of CNSI ,but it needs to be further verified by a large sample clinical trial.

Transmembrane transport activity of paclitaxel regulated by fangchinoline in MDR1-mDCK II cells / 中国中药杂志

<p><b>OBJECTIVE</b>To research the regulation of transmembrane transport activity of paclitaxel influenced by fangchinoline in MDR1-MDCK II cells.</p><p><b>METHOD</b>Paclitaxel, one of the substrate of P-gp, was selected as the model drug. Verapamil hydrochloride was adopted as the active control to investigate the bilateral transport activity of paclitaxel regulated by fangchinoline in MDR1-MDCK II cells. RP-HPLC was applied to determine the concentration of paclitaxel in the transporting medium, which was used to calculate apparent permeability coefficient of paclitaxel across MDR1-MDCK I1 monolayer cells.</p><p><b>RESULT</b>The efflux rate of paclitaxel was faster than the absorption rates across the MDR1-MDCK II monolayer cells with highly expressed P-gp. The absorption rates of paclitaxel combinated with fangchinoline and verapamil hydrochloride respectively were remarkably increased and the efflux rate was decreased. The reversal effect of the fangchinoline was stronger than the verapamil hydrochloride with the same molar concention.</p><p><b>CONCLUSION</b>Fangchinoline can apparently decrease the efflux of paclitaxel and inhibit the multidrug resistance of antitumor drug mediated by P-gp.</p>

Studies on absorptive mechanism of lipophilic components of danshen from its hydroxypropyl-beta-cyclodextrin inclusion complex / 生物医学工程学杂志

Taking Tanshinon IIA as the target and using reversed phase high performance liquid chromatography,we have developed a rapid and sensitive assay for lipophilic components of Danshen (LCD) in perfusate. The model of intestinal absorption was used to determine the concentration of Tanshinon IIA in rats as an in situ model. The change of concentration of Tanshinon IIA was separately calculated according to Michaelis-Menten and the Fick's equation to investigate the absorptive limit step of the LCD. It was concluded that the limit step to absorption of LCD was at the dissolution, by assessing the fitting index or correlative index. On the basis of the conclusion, the experiment was designed to prepare the inclusive complex of the LCD with hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and to study its absorptive mechanism. With the increase of dosage of complex, its absorption did not show saturated phenomenon in gastro-intestinal tract in rats and the constant Ka did not show significant difference, suggesting that the transport of mechanism in vivo is similar to passive transport.

Preparation of cytarabine nanoparticle and study on the drug releasing mechanism / 生物医学工程学杂志

Cytarabine nanoparticle was prepared through emulsion polymerization method, and its releasing properties were studied. The results showed that releasing principle complied with biexponential equation and had characteristics of sustained releasing. The pharmacokinetics in rabbits complied with two-department model. Compared with cytarabine injection, cytarabine nanoparticle had prolonged t 1/2beta and MRT and reduced CL, which showed nanoparticle could significantly prolong the retention time of Ara-C and possess significant sustained releasing character.

A preoperative planning system for unilateral craniofacial malformation restoration surgery based on the volume measurement of eye sockets / 生物医学工程学杂志

The surgical treatment of craniofacial malformation is a sophisticated task which needs careful and detailed preoperative planning. However, based on the patient's 2-D CT and X-ray images, the surgeons always feel hard to produce a convincible and satisfying surgical scheme. In this article, a craniofacial surgery simulation system based upon 3-D reconstruction and volume calculation of two eye sockets is presented. By using this system, the surgeon can virtually repose bone fragment according to the D-value between the volumes of two eye sockets. The D-value serves as a guideline to direct the bone reposing. The simulated key steps of real surgical procedure are presented, which demonstrate the efficiency of the system. The contrast images between postoperative and preoperative surgery are also given.

Study on relative bioavailability of aspirin in afenca tablet / 生物医学工程学杂志

Salicylic acid is a kind of active metabolite of aspirin in vivo. In this study, its concentration in plasma was detected by RP-HPLC after twenty four healthy male volunteers were given each a single dose of oral Afenca test and reference preparations. The experiment data were calculated with 3P97 program. The results were analyzed by ANOVA and two- and one-sided t tests. The relative bioavailability of salicylic acid was 105.36% +/- 14.15%; AUC0-T of salicylic acid of test and reference preparations were 103.10 +/- 11.92 micrograms.h/ml and 98.45 +/- 13.49 micrograms.h/ml respectively; Tmax were 1.5 +/- 0.5 h and 1.5 +/- 0.5 h; Cmax were 19.31 +/- 2.47 micrograms/ml and 18.95 +/- 2.49 micrograms/ml. Bioequivalent evaluation of two preparations by analyzing with two- and one-sided t tests showed that the two preparations were bioequivalent on the basis of salicylic acid (t1 > or = t1-0.05(22), t2 > or = t1-0.06(22)).

Pharmacokinetics of alcohol extract of Radix Salviae Miltiorrhiaze in rat in vivo / 中草药

Objective To establish a sensitive HPLC method with UV detection for the determination of tanshinone Ⅱ_A(TSⅡ_A) and cryptotanshinone(CT) in rat plasma and to study pharmacokinetics of Radix Salviae Miltiorrhizae(RSM) liposoluble components in rat in vivo. Methods TS Ⅱ_A and CT in plasma of rat at different sampling time were determined by pretreatment with Gemifibrozil as internal standard,the protein was precipitated in methanol solution after iv administration of alcohol extract of RSM 5 mg/per animal.The mean plasma concentration-time curve was protracted and pharmacokinetic parameters were calculated by 3p87.Results The main pharmacokinetic parameters of TS Ⅱ_A were as follows: t_(1/2?) was(0.088?0.024) h;t_(1/2?) was(2.1?0.7) h;V_C was(0.8?0.6) L;CL was(2.0?1.1) L/h~(-1);AUC_(0-4) and AUC_(0-∞) were(2.2?0.9) mg?h/L and(3.4?1.7) mg?h/L,respectively.Conclusion The concentration-time curve of TS Ⅱ_A can be fitted to two-compartment model after ethanol extract of RSM iv administrated.Concentration of TS Ⅱ_A in rat plasma declines rapidly with large apparent volume of distribution.CT decreases also rapidly and it is difficult to acquire its pharmacokinetic parameters in rat.