RETRACTED ARTICLE: The Influence of Sodium Hyaluronate, <Emphasis Type="SmallCaps">l</Emphasis>-Leucine and Sodium Taurocholate on the Nebulization of Aqueous Betamethasone-17-Valerate Suspensions

The purpose of this research was to evaluate the variables that are suggested to influence the adsorption of the hydrophilic hyaluronic acid (HA) onto the surface of the hydrophobic betamethasone-17-valerate (BV) particles in order to formulate a nebulizable suspension. The adsorption of HA from aqueous solutions (0.04% to 0.16%, w/v) to a fixed BV concentration (0.04%, w/v) under different experimental conditions, was investigated. The method of preparation of HA-BV suspensions involved suspending BV particles either in the hydrated HA solution (method 1) or in water followed by addition of solid HA (method 2). Other variables like the time required for the adsorption to complete and temperature at which adsorption is carried out were studied. The nebulization of the suspensions was tested via an air jet nebulizer connected to a twin stage impinger. In order to improve the nebulization behavior of the optimized suspension, l-leucine or sodium taurocholate was incorporated in increasing concentrations (0.01–0.04%, w/v). The optimized suspension, having a nebulization efficiency of 33.75%, was achieved following the adsorption of HA (0.1%, w/v) onto BV particles adopting method 2 of preparation and extending for three days at 4 °C. Incorporation of either l-leucine or sodium taurocholate significantly decreased the aggregate size of the optimized suspension and consequently caused significant increases in the nebulization efficiency to reach 46.87% and 56.25%, respectively. An erratum to this article is available at .     

Analysis of severe acute respiratory syndrome coronavirus structural proteins in virus‐like particle assembly

SARS‐CoV has four major structural proteins: the N, S, M, and E proteins. To investigate the mechanism of SARS‐CoV assembly, we cloned the genes encoding these four proteins into the eukaryotic expression vector pCAGGS and transfected them into 293T cells. When all four expression vectors were co‐transfected VLP formed, as confirmed using electron microscopy. Using a rabbit polyclonal antibody specific to the N protein, N‐protein‐containing particles similar in size to the VLP were also observed by immunoelectron microscopy, indicating that the VLP contained the N protein. Co‐immunoprecipitation analyses demonstrated an interaction between the N and M proteins, suggesting that N protein binds directly to M protein to be incorporated into VLP.     

The efficacy of different hCG dose rates and the effect of hCG treatment on ovarian activity: ovulation, multiple ovulation, pregnancy, multiple pregnancy, synchrony of multiple ovulation; in the mare

Despite the widespread use of hCG to advance ovulation in the mare there is little information on efficacy of dose rates and any contraindications of its use. This study aims to investigate the effect of dose of hCG on ovulation within 48h and the effect of hCG on: ovulation, multiple ovulation (MO), pregnancy, multiple pregnancy (MP) rates and synchrony of MO; additionally whether any seasonal effect is evident. Sequential ultrasonic scanning was used to monitor the occurrence of ovulation, within 48h of treatment, in 1291 Thoroughbred mares treated with either 750iu hCG or 1500iu hCG s.c. Ovulation rate, type (single ovulations (SO), MO, synchronous, asynchronous) and subsequent pregnancy were then monitored in 1239 Thoroughbred mares on a commercial stud over 3 years, 536 of which were treated with 750iu hCG at mating, all mares were also allocated into groups according to month of mating. No significant difference existed between the two dose levels of hCG and no significant difference existed between treated and untreated mares in overall ovulations (1.32 and 1.28 respectively), MO (31.7% and 27.7%), pregnancy (65.1% and 65.6%) or MP rates (10.8% and 11.8%). There was no significant association between month of year and pregnancy or MP rates for either treated or control mares, nor for MO for untreated mares. A significant (p<0.05) association was evident between month and MO in treated mares, MO being lowest in April (22.3%). 95.9% of treated mares multiple ovulated within 48h compared with 90.7% controls, a near significant difference. In conclusion this study demonstrates that: (i) hCG dose of 750iu s.c. is just as effective in inducing ovulation within 48h as 1500iu, (ii) 750iu hCG has no significant effect on ovulation, MO, pregnancy or MP rates; (iii) a significant (p<0.05) association exists between season and MO in hCG treated mares; (iv) a tighter synchrony (ovulation within 48h) of MO is evident in hCG treated compared with control mares (p=0.052).     

Computationally assisted screening and design of cell-interactive peptides by a cell-based assay using peptide arrays and a fuzzy neural network algorithm

We developed a method of effective peptide screening that combines experiments and computational analysis. The method is based on the concept that screening efficiency can be enhanced from even limited data by use of a model derived from computational analysis that serves as a guide to screening and combining the model with subsequent repeated experiments. Here we focus on cell-adhesion peptides as a model application of this peptide-screening strategy. Cell-adhesion peptides were screened by use of a cell-based assay of a peptide array. Starting with the screening data obtained from a limited, random 5-mer library (643 sequences), a rule regarding structural characteristics of cell-adhesion peptides was extracted by fuzzy neural network (FNN) analysis. According to this rule, peptides with unfavored residues in certain positions that led to inefficient binding were eliminated from the random sequences. In the restricted, second random library (273 sequences), the yield of cell-adhesion peptides having an adhesion rate more than 1.5-fold to that of the basal array support was significantly high (31%) compared with the unrestricted random library (20%). In the restricted third library (50 sequences), the yield of cell-adhesion peptides increased to 84%. We conclude that a repeated cycle of experiments screening limited numbers of peptides can be assisted by the rule-extracting feature of FNN.     

Application of magnetic force-based cell patterning for controlling cell-cell interactions in angiogenesis

To investigate the effects of cell-cell interactions on cellular function, the microenvironment surrounding cells should be precisely controlled. Here, we describe a cell patterning technique, which utilizes magnetic force and magnetite nanoparticles. This method was used to develop cell culture arrays for investigation of cell behaviors in angiogenesis. Pin holder devices that contain more than 6,000 pillars on the surface are used for fabricating the cell culture arrays by setting it on a magnet. The magnetically labeled cells were arranged by magnetic distribution. When the human umbilical vein endothelial cells are arranged at 250 microm intervals (5.9 cells/spot), the cells spread toward other cell cluster on adjacent spots in 4.5 h, and formed cord-like structures in 8.5 h. It was shown that cell-cell interactions were successfully investigated using magnetic cell arrangement.     

NSC-87877, inhibitor of SHP-1/2 PTPs, inhibits dual-specificity phosphatase 26 (DUSP26)

Protein phosphorylation plays critical roles in many regulatory mechanisms controlling cell activities and thus involved in various diseases. The cellular equilibrium of phosphorylation is regulated through the actions of protein kinases and phosphatases. Therefore, these regulatory proteins have emerged as promising targets for drug development. In this study, we screened protein tyrosine phosphatases (PTPs) by in vitro phosphatase assays to identify PTPs that are inhibited by 8-hydroxy-7-(6-sulfonaphthalen-2-yl)diazenyl-quinoline-5-sulfonic acid (NSC-87877), a potent inhibitor of SHP-1 and SHP-2 PTPs. Phosphatase activity of dual-specificity protein phosphatase 26 (DUSP26) was decreased by the inhibitor in a dose-dependent manner. Kinetic studies with NSC-87877 and DUSP26 revealed a competitive inhibition. NSC-87877 effectively inhibited DUSP26-mediated dephosphorylation of p38, a member of mitogen-activated protein kinase (MAPK) family. Since DUSP26 is involved in survival of anaplastic thyroid cancer (ATC) cells, NSC-87877 could be a therapeutic reagent for treating ATC.     

Laccase production in solid‐state and submerged fermentation by Pleurotus ostreatus

A solid‐state fermentation (SSF) system for production of an industrially important enzyme laccase by Pleurotus ostreatus was developed by using potato dextrose yeast extract medium and polyurethane foam as a supporting material. The maximum laccase production in the SSF system was as high as 3×10⁵ U/L. Addition of inducers, such as copper and ferulic acid, further enhanced the laccase production in SSF. Moreover, the time required for the maximum laccase production was reduced to 6 days compared to 10 days reported earlier. The improvement achieved by the SSF system was investigated by comparing it to a submerged fermentation system (SmF), both experimentally and by using a standard theoretical model along with a parameter sensitivity analysis. Laccase production in SSF was found to be twice of that in SmF. One of the main reasons for higher laccase production in SSF compared to SmF was possibly due to the presence of higher proteolytic activity in SmF. Strong proteolytic activity in SmF presumably caused subsequent laccase degradation, which lowered the ultimate laccase production in SmF compared to SSF.