Photocontrolled nanoparticles for on-demand release of proteins

We describe here light-regulated swelling and degradation features of polymeric nanoparticles that are produced using an inverse microemulsion polymerization method. We demonstrate the phototriggered release characteristics of the nanoparticles by sequestering protein molecules and releasing them using light as a trigger. Furthermore, the intracellular translocation of the nanoparticles, along with its fluorescent protein payload, was achieved using a cell-penetrating peptide-based surface modification. We expect that the noncovalent encapsulation of proteins using nanoparticles and their photo triggered release using an external light would provide opportunities for achieving intracellular release of molecular therapeutics for on-demand requirements.     

Magnetic separation of CD14+ cells using antibody binding with protein A expressed on bacterial magnetic particles for generating dendritic cells

Herein the potential of a highly efficient cell separation system using bacterial magnetic particles expressing protein A (protein A-BacMPs) was demonstrated. Protein A was expressed on BacMPs using the transmembrane proteins Mms13 and MagA as anchor molecules. The evaluations of the numbers of bound antibody molecules and binding capabilities of the protein A-BacMPs using Mms13 indicated that the antibodies were efficiently introduced into protein A-BacMPs using Mms13 in comparison to MagA. In addition, the recovery ratio of the target cells on the magnetic cell separation system was enhanced by using protein A-BacMPs with Mms13. Using positive selection against peripheral blood mononuclear cells, the CD14(+) cells were separated at a purity of more than 99% by protein A-BacMPs using Mms13. Furthermore, in the evaluation of the influence of protein A-BacMPs on the separated cells, the CD14(+) cells separated using protein A-BacMPs and were successfully differentiated into dendritic cells.     

De novo design: backbone conformational constraints in nucleating helices and beta-hairpins.

A modular approach to synthetic protein design is being developed using conformationally constrained amino acid as stereochemical directors of polypeptide chain folding. An overview of studies aimed at constructing peptide helices using alpha,alpha-dialkyated residues and beta-hairpins using D-Pro as a turn nucleator is presented. The construction of helix-helix motifs and three- and four-stranded structures has been achieved using non-protein amino acids to stabilize specific elements of secondary structures.     

Further analysis of familial transmission of congenital glaucoma.

A re-analysis of familial transmission of congenital glaucoma is performed here using the unified model and considering, respectively, joint and conditional likelihoods. Whereas the familial aggregation of this malformation is consistent with the segregation of a recessive major gene and a high proportion of sporadic cases using conditional likelihood, this is rejected using joint likelihood. The difference in the results obtained using each of these two strategies is discussed.     

经鼻蝶入路显微侵袭切除垂体腺瘤的临床疗效

目的:对比观察经鼻蝶显微技术下入路与经鼻蝶神经内窥镜下入路手术切除垂体腺瘤的疗效,探讨切除垂体瘤的良好辅助方法。方法:78例患者分别采用经鼻蝶显微技术下入路和经鼻蝶神经内窥镜下入路手术切除垂体腺瘤。结果:与经鼻蝶显微技术下入路比较,经鼻蝶神经内窥镜下入路手术者住院时间短、肿瘤全切除率高、鼻出血率低、术后并发症发生率低(P<0.05),但是经鼻蝶神经内窥镜下手术切除肿瘤时术中出血需显微镜下止血。结论:经鼻蝶神经内窥镜下手术入路是垂体腺瘤切除的良好手术切除垂体瘤的入路,如有条件也可将二者联合应用取长补短。     

Solvent and solid-phase extraction of natural and synthetic anabolic steroids in human urine

Liquid–liquid (using dichloromethane) and liquid–solid extraction processes (using disposable C₁₈ cartridges) were applied to human urine samples spiked with 15 androgenic anabolic steroids (natural and synthetic). The extraction recoveries were assessed from different HPLC separations of anabolic steroids using water–acetonitrile mobile phase, and using calibration graphs obtained by injection into HPLC of standard samples of these compounds before and after extraction. The procedures, including sample preconcentration, showed extraction efficiencies over 90% which were independent on a wide range of concentrations tested. Solid phase extraction yielded poor results for oximetolone, danazol and dehydroepiandrosterone. For real urine samples, hydrolysis using β-glucuronidase and washing using sodium hydroxide before and after solvent extraction, respectively, is recommended.     

地塞米松与甲硝唑在防治根管治疗期间急症中的联合应用

目的:观察联合应用地塞米松与甲硝唑行根管治疗期间急症处理的效果。方法:对66例根管治疗期间急症发作的病例分别采用联合应用地塞米松与甲硝唑、单独使用地塞米松和单独使用甲醛甲酚的方法治疗,观察各组的差异。结果:地塞米松与甲硝唑联合应用组的治疗效果优于其他组,差异显著。结论:联合应用地塞米松与甲硝唑可有效治疗根管治疗期间急症。     

Bayesian inference for prevalence in longitudinal two-phase studies

We consider Bayesian inference and model selection for prevalence estimation using a longitudinal two-phase design in which subjects initially receive a low-cost screening test followed by an expensive diagnostic test conducted on several occasions. The change in the subject's diagnostic probability over time is described using four mixed-effects probit models in which the subject-specific effects are captured by latent variables. The computations are performed using Markov chain Monte Carlo methods. These models are then compared using the deviance information criterion. The methodology is illustrated with an analysis of alcohol and drug use in adolescents using data from the Great Smoky Mountains Study.     

Quantitation of phosphotyrosine signals in human prostate cell adhesion sites

A simple method is described for the quantitation of phosphotyrosine signaling in human prostate cell cultures. The phosphotyrosine signals are observed by standard immunohistochemistry techniques, and the resulting digital images are analyzed using the Scion image software program. The signals within the cell adhesion sites are quantitated using the density slice and particle analysis features of the software. The immunohistochemistry results are compared with detection of phosphotyrosine signals using a standard Western blotting procedure with whole cell lysates. The resulting data is converted into graphs using the Sigma Plot Program. This method is illustrated using damage-induced signaling within cell adhesion sites after a low dose of ionizing radiation.     

Preliminary evaluation of greenhouses employing positive-pressure forced ventilation to prevent invasion by insect pests

We conducted a preliminary comparison of greenhouses using positive-pressure forced ventilation (PFV) systems and natural ventilation (NV) systems, and assessed the effectiveness of both systems for preventing the invasion of greenhouses used to cultivate tomatoes by insect pests. In Trial 1 (August–December 2006), greenhouses using a PFV system and an insect-proof screen (mesh size 1.0 mm) had fewer sweetpotato whiteflies and Bemisia tabaci (Gennadius), and more onion thrips, Thrips tabaci (Lindeman), than greenhouses that employed an NV system fitted with the same screen. Tomato leafminers, Liriomyza sativae Blanchard, were not observed in the greenhouse using the PFV system, but some were observed in the greenhouse using the NV system. In Trial 2 (August–December 2007), the greenhouse using the PFV system combined with an insect-proof screen (mesh size 0.4 mm) had higher whitefly densities after late October compared to the greenhouse using the NV system and the same screen. However, there were more thrips in the greenhouse using the PFV system compared to the greenhouse using the NV system. In both trials, Tomato yellow leaf curl virus, which is transmitted by B. tabaci, was recorded in the greenhouse using the NV system but not in the greenhouse using the PFV system. The results showed that the PFV system was effective for preventing invasion by leafminers and partially effective for preventing invasion by whiteflies, but not effective for preventing invasion by thrips.     

Epoxy-amino groups: a new tool for improved immobilization of proteins by the epoxy method

The properties of a new commercially available amino-epoxy support (amino-epoxy-Sepabeads) for immobilizing enzymes have been compared to those of conventional epoxy supports. The new support has a layer of epoxy groups over a layer of ethylenediamine that is covalently bound to the support. Thus, this support has a great anionic exchanger power and a high number of epoxy groups. We have found a number of advantages to this new heterofunctional support. Immobilization proceeds at low ionic strength using amino epoxy Sepabeads while requiring high ionic strength using conventional monofunctional epoxy supports. Immobilization is much more rapid using amino-epoxy supports than employing conventional epoxy supports. The possibility of achieving immobilized preparations in which the enzyme orientation may be different to that obtained using the traditional hydrophobic supports (with likely effects in terms of activity or stability). Stability of the immobilized enzyme has been found to be much higher using the new support than in preparations using the conventional ones in many cases. Here we show some examples of these advantages using different enzymes (beta-galactosidases, lipase, glutaryl acylase, invertase, and glucoamylase).     

Comparison between agarose gel electrophoresis and capillary electrophoresis for variable numbers of tandem repeat typing of Mycobacterium tuberculosis

Variable numbers of tandem repeat (VNTR) typing of Mycobacterium tuberculosis was performed on 54 strains including 23 strains derived from 9 outbreaks. PCR amplicon sizes of 12 mycobacterial interspersed repetitive unit tandem repeat loci were measured using both agarose gel electrophoresis and capillary electrophoresis. Similarities using agarose gel electrophoresis of Euclidian distances among the 23 strains derived from the 9 outbreaks were significantly lower than that using capillary electrophoresis (Wilcoxon signed ranks test, P < 0.01). By clustering analysis using unweighted pair group method using arithmetic averages, all of the 23 strains derived from the 9 outbreaks were each clustered with more than 90% similarities based on the distance using capillary electrophoresis. In contrast, differential clusters with more than 90% similarity were observed with only 7 strains derived from 3 outbreaks when analyzed by agarose gel electrophoresis. These results indicated that measurement of PCR amplicon size of tandem repeat loci should be carried out using capillary electrophoresis and that agarose gel electrophoresis is not suitable for clustering analysis of M. tuberculosis VNTR typing.     

Measurements of DNA and RNA in mammary gland homogenates by the ethidium bromide technique.

A rapid method of determining simultaneously DNA and RNA in mammary gland homogenates using the ethidium bromide technique is discussed. The method utilizes a quantitative extraction of DNA and RNA with 2.0m sodium chloride, SDS, and EDTA at pH 8.0. Assays of mammary gland RNA and DNA using previously published methods were compared with determinations using the ethidium bromide technique. While the fluorescence method gave lower values for RNA when compared to those obtained using the orcinol or absorbancy ratio (OD 260nm/280nm), DNA measurements agreed well with the values determined by the diphenylamine technique. Extinction coefficient data for total mammary gland RNA isolated using a modified phenol extraction procedure are also presented.     

Xeno-free proliferation of human bone marrow mesenchymal stem cells

The proliferation of human bone marrow mesenchymal stem cells (MSCs) employing xeno-free materials not containing fetal calf serum (FCS) and porcine trypsin was investigated for the regenerative medicine of cartilage using MSCs. Four sequential subcultivations of MSCs using a medium containing 10% FCS and recombinant trypsin (TrypLESelect™) resulted in cell growth comparable to that with porcine trypsin. There was no apparent difference in the cell growth and morphology between two kinds of MSC stored in liquid nitrogen using 10% FCS plus DMSO or serum-free TC protector™. MSCs were isolated from human bone marrow cells, stored in liquid nitrogen, and sequentially subcultivated four times employing conventional materials that included FCS, porcine trypsin, and DMSO, or xeno-free materials that included serum-free medium (MesenCult-XF™), TC protector™ and TrypLESelect™. Cells in the culture using the xeno-free materials maintained typical fibroblast-like morphology and grew more rapidly than the cells in the culture using the conventional materials, while the cell surface markers of MSCs (CD90 and CD166) were well maintained in both cultures. Chondrogenic pellet cultures were carried out using these subcultivated cells and a medium containing TGFβ3 and IGF1. The pellet culture using cells grown with the xeno-free materials showed an apparently higher gene expression of aggrecan, a chondrocyte marker, than the pellet culture using cells grown with the conventional materials. Consequently, MSCs that are isolated, stored, and grown using the xeno-free materials including the serum-free medium (MesenCult-XF™), TC protector™, and recombinant trypsin (TrypLESelect™) might be applicable for regenerative medicine of cartilage.     

Herbivory and plant resource competition: a review of two interacting interactions

This review discusses the prevalence and potential for interactive effects between herbivory and competition on plant growth and biomass, and it is apparent that such effects typically arise when there is a mismatch between the spatial scale of herbivore behaviour (food or patch choice) and the spatial heterogeneity of the plant community. Historically, such interactive effects have been examined using two approaches. Studies using the first approach have excluded plant neighbors and herbivores in a factorial experiment, and scored effects on plant biomass. Studies using the second approach have observed herbivore abundance or herbivory on plants with or without plant neighbors, and have identified a large number of mechanisms underlying such interactive effects. The two types of studies have produced somewhat conflicting results, where interactive effects have been commonly observed in studies using the second approach and only rarely in studies using the first approach. This is most likely a consequence of a biased choice of study systems, where studies using the first approach have primarily studied mammalian herbivory while studies using the second approach have been more focussed on insect herbivory. Moreover, studies using the first approach have typically been very small-scale manipulations and this probably precludes most possible interactive effects in systems with mammalian herbivory. This points to the fact that studies examining interactive effects of herbivory and plant competition should more carefully consider the behaviour and life history of herbivores included in the study prior to the design of removal experiments.     

Assay of timolol in human plasma using gas chromatography with electron-capture detection

A simple and sensitive gas chromatographic method has been developed for the determination of timolol in plasma using electron-capture detection and propranolol as internal standard. Timolol was extracted using butyl chloride and derivatized using trifluoroacetic anhydride in butyl acetate. The lower detection limit for the assay was found to be 1 ng/ml from 1 ml of plasma. Extracted standards gave within-day precision of 12.55, 9.68 and 3.78% for 1, 20 and 100 ng/ml plasma samples, respectively. A recovery of at least 80% of timolol was found using the extraction method described. The assay was used in a randomized cross-over bioequivalence trial using an oral administration of 20 mg of timolol. Pharmacokinetic parameters compare favourably with other literature values.     

The phase diagram of the Lennard-Jones fluid using temperature dependent interaction parameters

The forces of interaction between argon atoms can be described by the Lennard-Jones potential model. It is hypothesised that the use of temperature dependent interaction parameters, instead of using temperature independent interaction parameters, may lead to improvement in the prediction of the vapour–liquid coexistence curve. Published second virial coefficient data were used to fit a simple two-parameter temperature dependent model for the collision diameter and well depth. Vapour–liquid coexistence curve for argon was simulated in the NVT Gibbs ensemble Monte Carlo technique. The simulations were carried out using each of the temperature independent and temperature dependent parameters in the temperature range: 110–148 K. The critical temperature and density were determined using the Ising-scaling model. The results using temperature dependent parameters produce, overall, a more accurate phase diagram compared to the diagram generated using temperature independent interaction parameters. The root mean square deviation is reduced by 42.1% using temperature dependent interaction parameters. Also, there was no significant difference between the results obtained using temperature dependent interaction parameters and the highly accurate and computationally demanding phase diagrams based on three body contributions.     

2007-2008陕西部分零售畜禽肉沙门氏菌血清型和基因型

【目的】研究359株在2007-2008年分离于陕西部分地区零售畜禽肉中沙门氏菌的血清型和基因型,为确保食品安全提供依据。【方法】使用WHO指定的泰国SA公司的沙门氏菌诊断血清,采用玻片凝集法测定沙门氏菌的血清型。使用美国疾病预防控制中心推荐的脉冲场凝胶电泳方法确定沙门氏菌的DNA酶切图谱,BioNumerics软件分析电泳结果,确定沙门氏菌的基因型。【结果】359株沙门氏菌共检出24个血清型,以肠炎沙门氏菌(Salmonella Enteritidis)、鼠伤寒沙门氏菌(S.Typhimurium)、舒卜拉沙门氏菌(S.Shubra)、印第安纳沙门氏菌(S.Indiana)和德尔卑沙门氏菌(S.Derby)等为主,不常见血清型有圣保罗沙门氏菌(Salmonella Saintpaul)、里地乌沙门氏菌(S.Rideau)、田纳西沙门氏菌(S.Tennessee)、汤卜逊沙门氏菌(S.Thompson)、加里玛沙门氏菌(S.Galiema)、卡罗尔沙门氏菌(S.Kallo)、沙门氏菌Ⅲa(S.Ⅲa)、罗森沙门氏菌(S.Rissen)和布兰卡斯特沙门氏菌(S.Brancaster)等。鸡肉中最常见血清型为肠炎沙门氏菌,猪肉和羊肉中以德尔卑沙门氏菌检出率最高,而牛肉中以里地乌沙门氏菌为主。359株沙门氏菌使用XbaⅠ酶切分型后,按照88%的基因同源性,可分为7个大簇。同一血清型的沙门氏菌分型后基本位于同一大簇之中,虽然部分沙门氏菌的血清型不同,但分型后仍表现出较高的基因同源性和相似的基因型。【结论】陕西零售肉沙门氏菌的血清型和基因型表现为多样性的特征。     

Prevalence Rates of Uterine Cervical Carcinoma in situ for Women Using the Diaphragm or Contraceptive Oral Steroids

Study of the prevalence rates of uterine cervical carcinoma in situ among women attending centres of Planned Parenthood of New York City, Inc., showed a small but statistically significant difference between the population choosing and using the diaphragm and the population choosing and using oral steroids for contraception. This can be attributed either to a decreased prevalence rate for women using the diaphragm or to an increased rate for women using oral steroids. The reason for the difference is not apparent from these data.