Immunogenicity of the envelope GP3 protein of porcine reproductive and respiratory syndrome virus displayed on baculovirus

Porcine reproductive and respiratory syndrome virus (PRRSV) has been recognized as one of the most important pathogens of pigs throughout the world. The minor envelope protein GP3 of PRRSV plays an important role in clearing of the virus infection and protecting the animals. In this study, a recombinant baculovirus (BacSC-GP3) expressing His6-tagged GP3 with the transmembrane (TM) and cytoplasmic (CT) domains of envelope protein gp64 was constructed and its immunogenicity was evaluated in mouse and piglet models. The His6-tagged GP3 was successfully displayed on the surface of virions as well as virus-infected Sf-9 cells. The animals immunized with BacSC-GP3 gave a slightly higher (piglets) up to a markedly higher (mice) humoral and lymphocyte proliferation responses than those that received a commercial killed vaccine. This is the first study on the immunogenicity of recombinant GP3-baculovirus, which indicates that the latter can represent an alternative strategy for developing a more effective PRRSV vaccine.

CC chemokine ligand 21 enhances the immunogenicity of the breast cancer cell line MCF-7 upon assistance of TLR2

CC chemokine ligand 21 (CCL21) is a known attractant for CCR7-positive (CCR7+) cells, but its additional role in the immunogenicity of CCR7+ cells remains poorly understood. This study explored the effects of CCL21-CCR7 ligation on cancer immunogenicity and related antitumor immune response, in the presence and absence of mitomycin C (MMC) treatment. CCL21-CCR7 binding upregulated human leukocyte antigen class I-restricted tumor antigen presentation with increased expression of human leukocyte antigen class I and transporter associated with antigen processing-1. In addition, CCL21 restrained the tumor-derived immunosuppressive factors FasL and transforming growth factor-β. Consequently, CCL21 facilitated cancer-educated lymphocytes reaction in vitro. In the tumor-bearing mouse, CCL21 inhibited tumor growth and prolonged mouse survival via lymphocytes, especially in CCR7+ cancer cells. Furthermore, Toll-like receptor 2 activation of lymphocytes assisted the tumor-suppression functions of CCL21, in vitro and in vivo. This study implies that CCL21 improved the immunogenicity of the CCR7+ breast cancer cell line even with MMC treatment and triggered antitumor response by lymphocytes. These findings provide a new insight into the research and application of CCL21-associated antitumor response.

Theoretical study of alkali atom doped outside 4 angstroms carbon nanotubes

Using first-principles calculations, we study the doping of alkali atoms on the outer surface of 4 angstroms single-walled carbon nanotubes. It is found that the exterior doping at the "center" site is more favorable than the interior doping along tube axis. The calculated binding energies show a strong chirality dependence, and the alkali atoms tend to be bound strongest with the (5, 0) tube. The change of band structure upon doping is studied and the charge transfer between tube and alkali atom is shown. Our calculations indicate that the Li storage capacity can be reached to a maximum of LiC2.5, which suggests that the 4 angstroms nanotube could be a plausible candidate for Li-ion battery applications.

Structure effects in angle-resolved high-order above-threshold ionization of molecules

We present energy-resolved angular distributions of photoelectrons generated in above-threshold ionization (ATI) of nonaligned diatomic molecules N2 and O2 in high-intensity short laser pulses, with emphasis on the most energetic part of the spectra. The angular distribution for photoelectrons with energy of 10U(p) (U(p): ponderomotive energy), i.e., the plateau cutoff in ATI spectra, is found to be broader in O2 than in N2. Resorting to the analyses from both an S-matrix theory and an intuitive semiclassical model, we attribute the observation to the effect of the ground state molecular orbital structure on high-energy electron emission in strong-field molecular ionization.

Energetics of Stone-Wales defects in 4 A carbon nanotubes

Density functional calculations have been performed to study the formation of Stone-Wales defects in 4 A single-wall carbon nanotubes, which were firstly synthesized inside the AFI zeolite template. The minimum energy paths from perfect tubes to defect-containing ones are calculated by the nudged elastic band method. It is found that the C--C bonds "along" the tube axis are more likely to be rotated than those bonds "around" the circumference. There is a marked chirality dependence of the formation barriers, which are found to be lower than that of graphite. Our results may raise a question on the origin of superconductivity observed in these 4 A tubes.

Manufacturing of 50 kA superconducting transformer for ITER correction coil conductor test

To meet the specifications of International Thermonuclear Experimental Reactor correction coil (CC) conductor, a 50 kA superconducting transformer has been designed and manufactured to provide the short sample of the CC conductor the current. The transformer consists of two concentric layer-wound superconducting solenoids with the primary inside the secondary coil. In order to test the transformer, the two legs of the secondary coil were directly connected by superconducting cables. A 500 W/4.5 K refrigerator was used to provide the supercritical helium. The maximum current of 56.3 kA in the secondary coil loop was obtained.

Electronic and electrochemical properties of Li-doped carbon nanotube-zeolite complex

The electronic and electrochemical properties of Li-doped carbon nanotube-zeolite complex are studied by first-principles calculations. There are four possible sites for Li to be doped and the reactions are all exothermic. The corresponding energy band structures follow a rigid band picture and there are charge transfers from Li to the nanotube and/or zeolite. The Li capacity of the complex can be reached to 386 mAh g(-1) with only a slight increase in the cell volume, and the complex may be of good cyclic stability during the charge and discharge process. Moreover, a higher voltage of about 4 V can be obtained if the complex is used in an Li-ion battery.

Migration of a swallowed toothpick into the liver: the value of multiplanar CT

Foreign body ingestion is not an uncommon problem encountered in clinical practice. However, the associated complication of bowel perforation and migration of the foreign body to the liver is rare. We report two cases of hepatic foreign bodies identified intra-operatively as toothpicks, with the alimentary tract being the presumed origin.

Inhibitions of vascular endothelial growth factor expression and foam cell formation by EGb 761, a special extract of Ginkgo biloba, in oxidatively modified low-density lipoprotein-induced human THP-1 monocytes cells

It has been reported that oxidatively modified low-density lipoprotein (Ox-LDL) involvement with vascular endothelial growth factor (VEGF) and foam cell formation play an important role in atherosclerosis (AS). Protective effects of Ginkgo biloba extract (EGb 761) have been identified for some cardiovascular and neurological disorders. The aim of this study was to investigate whether Ox-LDL regulates VEGF expression in human THP-1 monocytes, as well as the effect of EGb 761 on VEGF expression and the formation of foam cells. After exposure to Ox-LDL alone or in combination with EGb 761 for up to 48h, cell viability was measured using the MTT assay. VEGF protein content in the supernatant was analyzed by enzyme-linked immunosorbent assay (ELISA). VEGF mRNA was determined by real-time PCR. To determine the effect of EGb 761 on foam cell formation, an Ox-LDL-induced foam cell model was used. Ox-LDL inhibited the growth of THP-1 cells and EGb 761 increased the cell survival rate. Ox-LDL markedly increased VEGF expression in THP-1 cells in a time- and concentration-dependent manner, which was significantly suppressed by EGb 761. EGb 761 also inhibited monocyte/macrophage-derived foam cell formation. These results suggest that Ox-LDL is involved in the development of human AS through VEGF induction in monocytes, and that EGb 761 prevents in vitro atherogenesis, probably via downregulation of VEGF expression in monocytes and inhibition of monocyte/macrophage-derived foam cell formation. The findings suggest a mechanism for the in vivo anti-AS effect of EGb 761 and support its potential clinical use in AS.

Modified sublimation to isolate phenanthrene-degrading bacteria of the genera Sphingomonas and Burkholderia from Xiamen oil port

Sublimation was developed by Alley and Brown (2000) in order to isolate bacterial strains that were capable of degrading water insoluble compounds. In this study, sublimation was modified by the use of nutritional agar plates, instead of mineral salt agar, to isolate phenanthrene-degrading bacteria from a mixed culture that had been enriched under the selective pressure of high phenanthrene content. Five strains were obtained with different morphology and degradation ability. Based on the 16S rDNA sequence, two of them were classified as species of the genus Sphingomonas; the others as species of the genus Burkholderia. Denaturing gradient gel electrophoresis (DGGE) was introduced to detect dynamic changes in the bacterial community during enrichment batch culture, and to determine any correlation between the five isolates and the phenanthrene-degrading consortium. The DGGE profile indicated that these five isolates corresponded to four dominant bands of the consortium. Compared to traditional means of isolation, we concluded that modified sublimation is effective and more convenient.

Sphingosine kinase 1 gene transfer reduces postoperative peritoneal adhesion in an experimental model

BACKGROUND

Recovery of the surgically damaged mesothelial cell layer is a major process in reducing postoperative peritoneal adhesions. Sphingosine kinase (SPK) 1 is a signalling molecule involved in the regulation of proliferation and migration of various cell types. This study determined the effect of SPK-1 gene transfer on the recovery of damaged mesothelial cells and on peritoneal adhesion formation after surgery.

METHODS

Rat mesothelial cells were isolated and characterized by their expression of cytokeratin and vimentin. Their migration was determined by scratch wound motility assay. Cellular SPK-1 activity was measured by [gamma-32P]adenosine 5'-triphosphate incorporation. Wistar rats underwent laparotomy with subsequent caecum or uterine horn abrasion. Rats were randomized to either SPK-1 gene (Ad-SPK-1) transfer or control groups. The animals were killed 14 days after operation and peritoneal adhesions were graded.

RESULTS

Adenovirus-mediated SPK-1 gene transfer increased the cellular SPK-1 activity of mesothelial cells, leading to enhanced migration. Median adhesion scores were significantly lower in the Ad-SPK-1 group than in controls in both rat caecum (0.98 versus 2.60; P < 0.001) and rat uterine horn (0.28 versus 1.83; P < 0.001) models.

CONCLUSION

Adenovirus-mediated SPK-1 gene transfer promotes recovery of the surgically damaged mesothelial cell layer and prevents postoperative peritoneal adhesion formation.

PAHs contamination and bacterial communities in mangrove surface sediments of the Jiulong River Estuary, China

Sixteen sediment samples collected from eight transects in a mangrove swamp of the Jiulong River Estuary, Fujian, China were investigated for their content of polycyclic aromatic hydrocarbons (PAHs) and the biodegradation potential of the indigenous microorganisms. The bacterial community structures in the mangrove sediments and in enrichment cultures were also investigated. The results showed that the total PAHs concentration of mangrove sediments ranged from 280 to 1074 ng g(-1) dry weight, that the PAHs composition pattern in the mangrove sediments was dominated by high molecular weight PAH components (4-6 rings), and that Benzo[ghi]perylene and Indeno[1,2,3-cd]pyrene were the most dominant at different stations. Abundant PAH-degrading bacteria were found in all the stations, the values of phenanthrene-degrading bacteria ranged from 5.85 x 10(4) to 7.80 x 10(5) CFU g(-1) dry weight, fluoranthene-degrading bacteria ranged from 5.25 x 10(4) to 5.79 x 10(5) CFU g(-1) dry weight, pyrene-degrading bacteria ranged from 3.10 x 10(4) to 6.97 x 10(5) CFU g(-1) dry weight and the benzo(a)pyrene-degrading bacteria ranged from 5.25 x 10(4) to 7.26 x 10(5) CFU g(-1) dry weight. DGGE analysis of PCR-amplified 16S rDNA gene fragments confirmed that there was a remarkable shift in the composition of the bacterial community due to the addition of the different model PAH compound phenanthrene (three ring PAH), fluoranthene(four ring PAH), pyrene(four ring PAH) and benzo(a)pyrene(five ring PAH) during enrichment batch culture. Eleven strains were obtained with different morphology and different degradation ability. The presence of common bands for microbial species in the cultures and in the native mangrove sediment DNA indicated that these strains could be potential in situ PAH-degraders.

Ketamine inhibits polymorphonuclear leucocyte CD11b expression and respiratory burst activity in endotoxemic rats

OBJECTIVE AND DESIGN

To observe the effect of ketamine on polymorphonuclear leucocytes (PMN) adhesion and respiratory burst activity in endotoxemia rats.

MATERIALS

30 rats were randomly allocated to five groups: rats challenged with intraperitoneal injection of saline (saline group); challenged with intraperitoneal injection of LPS 10 mg/kg (LPS group); challenged with intraperitoneal injection of LPS 10 mg/kg and treated by intraperitoneal injection of ketamine 5, 25, 50 mg/kg at 0, 1, 2, 3, 4, 5 h after the injection of LPS, respectively (three ketamine treatment groups).

METHODS

PMN respiratory burst and CD11b expression were measured with flow cytometry at the end of 1 h, 4 h, and 6 h.

RESULTS

LPS challenge significantly increased PMN respiratory burst activity and CD11b expression when compared with the saline group (p < 0.01). There was a significant decrease in LPS-induced PMN respiratory burst activity and CD11b expression in three ketamine treatment groups when compared with LPS group (p < 0.01).

CONCLUSIONS

Ketamine significantly inhibits PMN CD11b expression and respiratory burst activity in endotoxemic rats.

Selective removal of organochlorine pesticides (OCPs) from aqueous solution by triolein-embedded composite adsorbent

A novel composite adsorbent (CA-T) was used for the selective removal of organochlorine pesticides (OCPs) from aqueous solution. The adsorbent was composed of the supporting activated carbon and the surrounding triolein-embedded cellulose acetate membrane. Scanning electron microscopy (SEM), N2 adsorption isotherms and fluorescence methods were used to characterize the physicochemical properties of CA-T. Triolein was perfectly embedded in the cellulose acetate membrane and deposited on the surface of activated carbon. The adsorbent was stable in water and no triolein leakage was detected during the test periods. Some organochlorine pesticides (OCPs), such as dieldrin, endrin, aldrin, and heptachlor epoxide, were used as model contaminants and removed by CA-T in laboratory batch experiments. The adsorption isotherm followed the Freundlich equation and the kinetic data fitted well to the pseudo-second-order reaction model. Results also indicated that CA-T appeared to be a promising adsorbent with good selectivity and satisfactory removal rate for lipophilic OCPs from aqueous solutions when present in trace amounts. The adsorption rate and removal efficiency for lipophilic OCPs were positively related to their octanol-water partition coefficients (log K(ow)). Lower residual concentrations of OCPs were achieved when compared to granular activated carbon (GAC).

Cloning and nucleotide sequencing of the second internal transcribed spacer of ribosomal DNA for three species of Eimeria from chickens in Taiwan

Coccidiosis of chickens caused by protozoan parasites of the genus Eimeria (Coccidia: Eimeriidae) is an enteric disease that results in great economic losses throughout the world, including Taiwan. Using polymerase chain reaction (PCR) with primers specific for the second internal transcribed spacer (ITS-2) of ribosomal DNA (rDNA), three species of Eimeria, E. tenella, E. maxima, and E. acervulina have been successfully characterised from chickens in Taiwan. The sizes of PCR products from various isolates representing these three species were between 370 and 580 base pairs (bp). After cloning and sequencing of the PCR products, high nucleotide sequence identity (96.8-100%) was observed within a species. In addition, ITS-2 nucleotide sequences for E. tenella had higher homology (98.5-99.3%) than E. maxima (81.6-96.5%) when compared with appropriate sequences deposited in GenBank. To our knowledge, this is the first report of a 412-bp ITS-2 sequence for E. acervulina from chickens.

Expression of phosphorylated Stat3, cyclin D1 and Bcl-xL in extramammary Paget disease

BACKGROUND

Stat3 (Signal transducer and activator of transcription-3) is an oncogene that plays a critical role in regulating fundamental processes associated with malignant transformation and cell survival. It participates in oncogenesis through upregulation of genes encoding apoptosis inhibitors (Bcl-xL) and cell cycle regulators (cyclin D1). The expression of Stat3, Bcl-xL and cyclin D1 protein has not been investigated in extramammary Paget disease (EMPD).

OBJECTIVES

To study the expression of phosphorylated Stat3 (p-Stat3), Bcl-xL and cyclin D1 protein in EMPD and to evaluate the relationships among them.

METHODS

Thirty-six tissue samples from 34 patients with primary EMPD were subjected to immunohistochemical staining for p-Stat3, cyclin D1 and Bcl-xL.

RESULTS

Thirty-five of 36 specimens were clearly positive for p-Stat3 in EMPD, while 30 of 36 and 32 of 36 were positive for cyclin D1 and Bcl-xL expression, respectively. In all of four invasive EMPD specimens, strong and frequent expression of these three molecules was evident; moreover, two invasive EMPD specimens with lymph nodal metastasis showed very strong nuclear and membranous p-Stat3 staining. Two metastatic lymph node specimens showed very strong nuclear and local membrane p-Stat3 staining. There were significant correlations between p-Stat3 and cyclin D1 expression and between p-Stat3 and Bcl-xL expression.

CONCLUSIONS

Our study shows that the expression of p-Stat3, cyclin D1 and Bcl-xL may play a pivotal role in the pathogenesis of EMPD.

Lattice dynamics and electron-phonon interaction in (3,3) carbon nanotubes

We present a detailed study of the lattice dynamics and electron-phonon coupling for a (3,3) carbon nanotube which belongs to the class of small diameter based nanotubes which have recently been claimed to be superconducting. We treat the electronic and phononic degrees of freedom completely by modern ab initio methods without involving approximations beyond the local density approximation. Using density functional perturbation theory we find a mean-field Peierls transition temperature of approximately 240 K which is an order of magnitude larger than the calculated superconducting transition temperature. Thus in (3,3) tubes the Peierls transition might compete with superconductivity. The Peierls instability is related to the special 2k(F) nesting feature of the Fermi surface. Because of the special topology of the (n,n) tubes we also find a phonon softening at the Gamma point.

Household gas cooking: a risk factor for respiratory illnesses in preschool children

AIMS

To explore the association of household gas cooking and respiratory illnesses in preschool children and their relation to outdoor air pollution.

METHODS

Cross-sectional study among households that used gas stoves for cooking in two housing estates with contrasting air qualities in Hong Kong. A structured questionnaire was administered to parents of 426 children aged 0-6 years on their exposure to gas cooking and passive smoking, and the prevalence of respiratory illnesses.

RESULTS

A total of 111 children (26.1%) were reported to have one or more respiratory illnesses (allergic rhinitis, asthma, bronchitis, sinusitis, and pneumonia). Of these, 21 (18.9%), 41 (36.9%), and 49 (44.1%) children were from households that cooked once, twice, and three times a day with gas. Hierarchical logistic regression models adjusting for socioeconomic, demographic, and indoor risk factors including passive smoking showed that household gas cooking was positively associated with respiratory illnesses. There was a dose-response relation between the frequency of gas cooking and the prevalence of respiratory illnesses in the estate with lower outdoor air pollution (OR = 6.1 and 3.2 respectively, for cooking three and two meals a day, compared to one meal a day). This relation was not observed in the more polluted estate. The association between the presence of a cigarette smoker in the household and the prevalence of respiratory illnesses was not significant.

CONCLUSIONS

As gas cooking is common in urban households, the findings could have important public health implications.

Enhancement of electrolarynx speech using adaptive noise cancelling based on independent component analysis

The electrolarynx provides a valuable means of verbal communication for people who cannot use their natural voice-production mechanism, but technology has changed very little since it was introduced in the 1950s. The presence of background noise degrades the resulting speech. In this study background noise was reduced by a new method, independent component analysis-based adaptive noise cancelling, which can remove noise components of the primary input signal based on statistical independence, by incorporating both second-order and higher-order statistics. The method shows better performance than the conventional least mean square algorithm. Acoustic analysis of the denoised electrolarynx speech revealed a significant reduction in the amount of background noise. Results from the perceptual evaluations indicated that the new filtering technique produced a noticeable improvement in the acceptability of the electrolarynx speech in a quiet environment (from 1.75 to 2.49, arbitrary units) or a noisy environment (from 0.59 to 1.82). In general, there was no significant improvement or degradation in intelligibility in the quiet environment (from 52.7 to 53.3). However, the processing did improve the intelligibility in a babble-noise environment (from 24.9 to 40.6). The improvement in acceptability and intelligibility may increase the communication ability of the user in daily situations.

The effectiveness of Tsu-San-Li (St-36) and Tai-Chung (Li-3) acupoints for treatment of acute liver damage in rats

This study investigated the effects of acupuncture on carbon tetrachloride (CCl4) induced acute liver injury in male rats (n=36). The experimental groups were injected with CCl4 before, during, or after acupuncture therapy. Acupoints similar to the human Tsu-San-Li (St-36) and Tai-Chung (Li-3) were needled bilaterally. Rats treated with CCl4 had higher levels of serum glutamate-oxalate-transaminase (sGOT) and serum glutamate-pyruvate-transaminase (sGPT). Comparing the experimental groups, biochemical and pathological parameters of liver injury were significantly reduced when rats were acupunctured after, not before, CCl4-induced hepatotoxicity. Acupuncture at the Tsu-San-Li and Tai-Chung acupoints cannot prevent acute liver injury but may be effective in treating liver injury induced by carbon tetrachloride in rats.

Decolorization of reactive bright red K2G dye: electrochemical process catalyzed by manganese mineral

This paper presents the results of the decolorization of azo dye K2G by the electrochemical process catalyzed by manganese mineral. It is proved that the MnOOH(s), main component of the manganese mineral, can catalyze the electrochemical process and enhance the decolorization efficiency. X-ray powder diffraction spectrum shows that the content of MnOOH(s) has not been changed at the end of the reaction. The effects of initial pH value, current density, concentration of electrolyte on the decolorization efficiency of the dye were investigated in detail. The initial pH effect on the decolorization efficiency of K2G dye is found not to be significant. The optimum current density is 0.26 A/dm2. In addition, a proposed catalyzing mechanism of manganese mineral is discussed in this paper.

Sequence and phylogenetic analysis of the sigmaA-encoding gene of avian reovirus

The full-length sigmaA-encoding gene nucleotide sequences (1251 bp) of ten avian reovirus (ARV) field-isolates and three vaccine strains were determined and analyzed to study the degree of genetic divergence and evolution. Strains were isolated over a 23-year period from different hosts, pathotypes, and geographic locations. A phylogenetic tree constructed from variation in the sigmaA nucleotide sequences among ARV isolates showed that Taiwanese isolates from different dates of isolation were grouped into two distant groups, indicating that they have evolved in nature. In paired identity analysis, there was over 97.3% nucleotide sequence identity in the sigmaA-encoding genes between group I Taiwanese isolates (T6, 750505, 919, and 918) and Japanese isolate OS161 as well as three US vaccine strains, suggesting that they might have descended from a common ancestor. However, the nucleotide sequences of these sigmaA-encoding genes varied extensively from those of group II Taiwanese isolates (601SI, R2/TW, 1017-1, 916, and 601G), displaying only 86% identity. These results revealed that the genetic diversity in the sigmaA-encoding gene of ARV correlated with the date of isolation and geographic locations.

Homogeneous preparation of fluorescent-derivatized insulin and its application to competitive chromatographic immunoassays

A homogeneously labeled insulin sample was prepared using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) as the fluorescent-labeling reagent, and this was successfully applied to a chromatographic immunoassay. This labeled insulin was prepared by tagging all the three amino groups with AQC. Both CE and chromatographic immunoassay experiments indicated that the prepared insulin still kept its immunoaffinity to its antibody. It was observed that appropriate concentrations of acetonitrile (ACN) were efficient in lowering the quenching of the fluorescent signal of tagged insulin, in keeping the dilute, tagged insulin in solution, and in improving its peak shape during a chromatographic immunoassay. The tagged insulin was found to be 20-400 times more sensitive than native insulin detected under ultraviolet detection conditions. A competitive chromatographic immunoassay system was set up and calibrated. The system was used for analyses of an insulin-spiked urine sample, with a 96% recovery obtained.