Agrobacterium-mediated transformation of the β-subunit gene in 7S globulin protein in soybean using RNAi technology

The objective of this study was to use RNA interference (RNAi) to improve protein quality and decrease anti-nutritional effects in soybean. Agrobacterium tumefaciens-mediated transformation was conducted using RNAi and an expression vector containing the 7S globulin β-subunit gene. The BAR gene was used as the selective marker and cotyledonary nodes of soybean genotype Jinong 27 were chosen as explant material. Regenerated plants were detected by molecular biology techniques. Transformation of the β-subunit gene in the 7S protein was detected by PCR, Southern blot, and q-PCR. Positive plants (10 T0, and 6 T1, and 13 T2) were tested by PCR. Hybridization bands were detected by Southern blot analysis in two of the T1 transgenic plants. RNAi expression vectors containing the soybean 7S protein β-subunit gene were successfully integrated into the genome of transgenic plants. qRT-PCR analysis in soybean seeds showed a clear decrease in expression of the soybean β-subunit gene. The level of 7S protein β-subunit expression in transgenic plants decreased by 77.5% as compared to that of the wild-type plants. This study has established a basis for the application of RNAi to improve the anti-nutritional effects of soybean.

Identification of genes associated with the increased number of four-seed pods in soybean (Glycine max L.) using transcriptome analysis

Seed number per pod is an important component of yield traits in soybean (Glycine max L.). In 2010, we identified a natural mutant with an increased number of four-seed pods from a soybean variety named 'Jinong 18' (JN18). Subsequent observations indicated that the trait was stably inherited. To identify and understand the function of genes associated with this mutant trait, we analyzed the genetic differences between the mutant (JN18MT01) and source variety (JN18) by transcriptome sequencing. Three types of tissues, axillary buds, unfertilized ovaries, and young pods at three different growth stages, V6, R1, and R3, were analyzed, respectively. The sequencing results yielded 55,582 expressed genes and 4183 differentially expressed genes (DEGs). Among these, the log2 ratio value of 162 DEGs was >10, and 13 DEGs had overlapping expression at three different growth stages. Comparisons of DEGs among three different growth stages yielded similar results in terms of the percentage of genes classified into each gene ontology (GO) category. DEGs were classified into 25 different functional groups in clusters of orthologous groups analysis. Proportions of the main functional genes differed significantly over developmental stages. A comparison of enriched pathways among the three developmental stages revealed that 646 unigenes were involved in 103 metabolic pathways. These results show that the development of four-seed pods is associated with a complex network involving multiple physiological and metabolic pathways. This study lays the foundation for further research on cloning and on the molecular regulation of genes related to the four-seed pod mutation.

A Meta-analysis of Sequential Intravenous/Oral Moxifloxacin Monotherapy for Treatment of Skin and Skin Structure Infections

Moxifloxacin is widely recognized for the treatment of bacterial infections of the respiratory tract such as community acquired pneumonia, acute bacterial sinusitis and acute exacerbations of chronic bronchitis. However, the use of moxifloxacin for skin infections is much valued in recent years. This study is to compare the clinical efficacy and safety of moxifloxacin monotherapy among adults with skin and skin structure infections. The meta-analysis of RCTs is conducted by searching Medline, Embase, Pubmed and the Cochrane Library. 6 RCTs, involving a total of 2608 patients, were included in the meta-analysis. English and Chinese language papers were reviewed. The results of the meta-analysis showed that the moxifloxacin monotherapy has similar clinical cure rate, bacteriological success rates and mortality compared with the control group. The drug-related adverse of moxifloxacin was significantly higher than that in the control group, although the overall incidence of adverse events, serious adverse events, and serious drug-related adverse events were similar between the compared treatment groups. Through this meta-analysis, we can draw a conclusion that moxifloxacin monotherapy has similar effectiveness and relative safety as other recommended antibiotics for the treatment of SSSIs. At the same time, it possesses the superior bacteria eradication rate. The once-daily dosing of moxifloxacin monotherapy may be a useful alternative for other recommended antibiotic therapy.

Microphthalmia-associated transcription factor/T-box factor-2 axis acts through Cyclin D1 to regulate melanocyte proliferation

OBJECTIVES

Control of cell proliferation is critical for accurate cell differentiation and tissue formation, during development and regeneration. Here, we have analysed the role of microphthalmia-associated transcription factor MITF and its direct target, T-box factor TBX2, in regulating proliferation of mammalian neural crest-derived melanocytes.

MATERIALS AND METHODS

Immunohistochemistry was used to examine spatial and temporal expression of TBX2 in melanocytes in vivo. RNAi and cell proliferation analysis were used to investigate functional roles of TBX2. Furthermore, quantitative RT-PCR, western blot analysis and flow cytometry were used to further scrutinize molecular mechanisms underlying TBX2-dependent cell proliferation.

RESULTS

TBX2 was found to be co-expressed with MITF in melanocytes of mouse hair follicles. Specific Tbx2 knockdown in primary neural crest cells led to inhibition MITF-positive melanoblast proliferation. Tbx2 knockdown in melan-a cells led to reduction in Cyclin D1 expression and G1-phase cell cycle arrest. TBX2 directly activated Ccnd1 transcription by binding to a specific sequence in the Ccnd1 promoter, and the defect in cell proliferation could be rescued partially by overexpression of Cyclin D1 in Tbx2 knockdown melanocytes.

CONCLUSIONS

Results suggest that the Mitf-Tbx2-Cyclin D1 pathway played an important role in regulation of melanocyte proliferation, and provided novel insights into the complex physiology of melanocytes.

DNA repair gene XRCC3 variants are associated with susceptibility to glioma in a Chinese population

The susceptibility to glioma is not well understood. It has been suggested that the X-ray cross complementing group 3 (XRCC3) gene influences the capacity to repair DNA damage, leading to increased glioma susceptibility. In this study, we evaluated the relationship between XRCC3 mutations and glioma risk. Genotypes were assessed in 389 Chinese glioma patients and 358 healthy controls. XRCC3 Thr241Met (rs861539) and 2 additional polymorphisms, rs3212112 (c.774+19T>G) and rs1799796 (c.562-14A>G), were directly sequenced. The frequency of the rs861539 T allele was significantly lower in the glioma group than in healthy controls [11.1 vs 17.7%, odds ratio = 0.62 (0.48-0.80), P < 0.001]; the frequencies of the CT or CT+TT genotypes differed between groups (18.5 vs 31%, 20.3 vs 33.2%, respectively). The frequency of the rs3212112 G allele was significantly higher in the glioma group than in healthy controls [15.8 vs 5.3%, odds ratio = 2.94 (2.07-4.17), P < 0.001]. The frequencies of the GT or TG+GG genotypes differed between groups (25.4 vs 7.8%, 28.5 vs 9.2%, respectively). This study demonstrates that the rs861539 and rs3212112 polymorphisms in the XRCC3 gene may influence the risk of glioma development in Chinese populations.

Analysis of quantitative trait loci for main plant traits in soybean

Plant traits are important indices for regulating and controlling yield ability in soybean varieties. It is important to comprehensively study the quantitative trait locus (QTL) mapping for soybean plant traits, cloning related genes, and marker assistant breeding. In this study, 236 F2 generation plants and a derivative group were constructed by using Jiyu50 and Jinong18, obtained from Jilin Province. A total of 102 simple sequence repeat markers were used to construct a genetic linkage map. With 2 years of molecular and phenotypic data, QTL analyses and mapping were conducted for soybean maturity, plant height, main stem node, main stem branch, seed weight per plant, and more. Five main plant traits were analyzed via inclusive composite interval mapping using QTL IciMapping v2.2. Using one-dimensional scanning, a total of 30 QTLs were detected and distributed across 1 (A1), 4 (C2), and 12 (G). There were 9 linkage groups, including 16 major QTLs. Using two-dimensional scanning, 7 pairs of epistatic QTL interactions for maturity and plant height were detected in the soybean.

Knockdown of Pim-3 suppresses the tumorigenicity of glioblastoma by regulating cell cycle and apoptosis

Products of the Pim (the proviral integration site for the Moloney murine leukemia virus) family of proto&mdash;oncogenes possess serine/threonine kinase activity and belong to the Ca2+/calmodulin&mdash;dependent protein kinase group. Pim&mdash;3, a member of the Pim family is closely linked to the development of a variety of tumors. However, the role of Pim&mdash;3 in human glioblastoma remains unknown. In this study, we elucidated the role of Pim&mdash;3 in the growth and apoptosis of glioblastoma cells. Western blotting was used for determination of protein levels, and shRNA was used for Pim&mdash;3 knockdown. The MTT assay was used to evaluate cell proliferation and flow cytometry was used to determine cell cycle status and the number of apoptotic cells. A mouse xenograft model was established by injecting nude mice with Pim&mdash;3&mdash;depleted glioblastoma cells in order to determine tumor growth in vivo. We demonstrated that Pim&mdash;3 was highly expressed in human glioblastoma cell lines. We also found that knockdown of Pim&mdash;3 by specific shRNA slowed decreased proliferation, induced cell cycle arrest in the G0/G1 phase, and increased apoptosis in glioblastoma cells. Pim&mdash;3 knockdown potently inhibited the growth of subcutaneously implanted glioblastoma cells in vivo. We further revealed that Pim&mdash;3 knockdown induced growth inhibition by reducing the levels of the anti&mdash;apoptotic protein Bcl&mdash;xl and cell cycle regulatory proteins, including cyclin D1 and Cdc25C, and increasing the levels of the pro&mdash;apoptotic protein Bax.

Quantitative FRET measurement using emission-spectral unmixing with independent excitation crosstalk correction

Quantification of fluorescence resonance energy transfer (FRET) needs at least two external samples, an acceptor-only reference and a linked FRET reference, to calibrate fluorescence signal. Furthermore, all measurements for references and FRET samples must be performed under the same instrumental conditions. Based on a novel notion to predetermine the molar extinction coefficient ratio (RC ) of acceptor-to-donor for the correction of acceptor excitation crosstalk, we present here a robust and independent emission-spectral unmixing FRET methodology, Iem-spFRET, which can simultaneously measure the E and RC of FRET sample without any external references, such that Iem-spFRET circumvents the rigorous restriction of keeping the same imaging conditions for all FRET experiments and thus can be used for the direct measurement of FRET sample. We validate Iem-spFRET by measuring the absolute E and RC values of standard constructs with different acceptor-to-donor stoichiometry expressed in living cells. Our results demonstrate that Iem-spFRET is a simple and powerful tool for real-time monitoring the dynamic intermolecular interaction within single living cells.

Severe influenza A(H1N1)pdm09 infection induces thymic atrophy through activating innate CD8(+)CD44(hi) T cells by upregulating IFN-γ

Thymic atrophy has been described as a consequence of infection by several pathogens including highly pathogenic avian influenza virus and is induced through diverse mechanisms. However, whether influenza A(H1N1)pdm09 infection induces thymic atrophy and the mechanisms underlying this process have not been completely elucidated. Our results show that severe infection of influenza A(H1N1)pdm09 led to progressive thymic atrophy and CD4⁺CD8⁺ double-positive (DP) T-cells depletion due to apoptosis. The viruses were present in thymus, where they activated thymic innate CD8⁺CD44^hi single-positive (SP) thymocytes to secrete a large amount of IFN-γ. Milder thymic atrophy was observed in innate CD8⁺ T-cell-deficient mice (C57BL/6J). Neutralization of IFN-γ could significantly rescue the atrophy, but peramivir treatment did not significantly alleviate thymic atrophy. In this study, we demonstrated that thymic innate CD8⁺CD44^hi SP T-cells have critical roles in influenza A(H1N1)pdm09 infection-induced thymic atrophy through secreting IFN-γ. This exceptional mechanism might serve as a target for the prevention and treatment of thymic atrophy induced by influenza A(H1N1)pdm09.

Genetic analysis of the major gene plus polygene model in soybean resistance to Leguminivora glycinivorella

In order to investigate the genetic characteristics of soybean Leguminivora glycinivorella resistance and to improve soybean resistance insectivorous breeding efficiency by applying the multi-generation joint analysis method of the major gene plus polygene model, 5 pedigrees and generations (P1, F1, P2, F2, and F2:3) were used as the materials to perform the soybean L. glycinivorella resistance multi-generation joint analysis. The results showed that soybean resistance to L. glycinivorella was controlled and inherited by an additive major gene plus additive, dominant polygene. The major gene had a negative additive effect (d = -0.1633). The combination of the anti-L. glycinivorella genes showed negative heterosis. Because the polygene additive effects were positive, the polygene effects would increase the insect herbivory rate in the F1 generation. This hybrid combination showed an insect herbivory rate polygenic heritability of 21.9556 and 54.3490% in the F2 and F2:3 pedigrees, which presented a high heritability. Therefore, it was appropriate to perform the selective breeding of the insect herbivory rate in the late generation.

Multifocal multiphoton microscopy based on a spatial light modulator

We present a new multifocal multiphoton microscope that employs a programmable spatial light modulator to generate dynamic multifocus arrays which can be rapidly scanned by changing the incident angle of the laser beam using a pair of galvo scanners. Using this microscope, we can rapidly select the number and the spatial density of focal points in a multifocus array, as well as the locations and shapes of arrays according to the features of the areas of interest in the field of view without any change to the hardware.

Synthesis of an Imidazoline Phosphate Surfactant and its Application on Corrosion Inhibition

An imidazoline phosphate surfactant is designed and synthesized, and its application on corrosion inhibition is evaluated from the following aspects: (1) concentration of inhibitor; (2) temperature; (3) concentration of acid. The imidazoline phosphate is also mixed with KI as an assistant agent, and the results from weight loss measurement show better inhibition efficiency.

Colloid retention mechanisms in single, saturated, variable-aperture fractures

The characterization of fractured aquifers is commonly limited to the methodologies developed for unconsolidated porous media aquifers, which results in many uncertainties. Recent work indicates that fractured rocks remove more particulates than they are conventionally credited for. This research was designed to quantify the number of Escherichia coli RS2-GFP retained in single, saturated, variable-aperture fractures extracted from the natural environment. Conservative solute and E. coli RS2-GFP tracer experiments were used to elucidate the relationships between dominant retention mechanisms, aperture field characteristics, and flow rate. A non-destructive method of determining a surrogate measure of a coefficient of variation (COV(S)) for each fracture was used to better understand the transport behaviour of E. coli RS2-GFP. The results from this research all point to the importance of aperture field characterization in understanding the fate and transport of contaminants in fractured aquifers. The mean aperture was a very important characteristic in determining particulate recovery, so were matrix properties, COV(s), and flow rate. It was also determined that attachment is a much more significant retention mechanism than straining under the conditions employed in this research. Finally, it was demonstrated that the dominant retention mechanism in a fracture varies depending on the specific discharge. An improved understanding of the mechanisms that influence the fate and transport of contaminants through fractures will lead to the development of better tools and methodologies for the characterization of fractured aquifers, as well as the ability to manipulate the relevant mechanisms to increase or decrease retention, depending on the application.

Characterization of a Tembusu virus isolated from naturally infected house sparrows (Passer domesticus) in Northern China

The house sparrow (Passer domesticus) is one of the most widely distributed wild birds in China. Tembusu virus (TMUV) strain, TMUV-SDHS, was isolated from house sparrows living around the poultry farms in Shandong Province, Northern China. Genetic analysis of E and NS5 genes showed that it had a close relationship with that of the YY5 strain, which can cause severe egg drop in ducks. Pathogenicity studies showed that the virus is highly virulent when experimentally inoculated into the ducks. These findings show that house sparrows carrying the Tembusu virus may play an important role in transmitting the virus among other species.

Characterization of 236 novel alleles at the HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1 loci from China Marrow Donor Program

Two hundred and thirty-six novel human leukocyte antigen (HLA) alleles are described from volunteer donors of the China Marrow Donor Program: 71 HLA-A alleles, 79 HLA-B alleles, 43 HLA-C, 16 HLA-DRB1 alleles, 26 HLA-DQB1 and 1 HLA-DPB1. Two hundred and thirteen (90.3%) of the 236 novel alleles are single nucleotide substitution variants when compared with their most homologous allele. Seventy-eight of these single nucleotide variants are silent substitutions. The remaining novel alleles differ from their most similar allele by two to four nucleotide substitutions. Some of the novel alleles encode amino acid changes at positions not previously reported to be polymorphic, such as codons 57, 62, 67, 41 and 52 in HLA-A alleles; codons 133, 156, 201 and 215 in HLA-B alleles; codons 74, 208 and 225 in HLA-C; codons 25, 32 and 72 in HLA-DRB1; codons 20, 39 and 77 in HLA-DQB1.

Association between corneal biomechanical properties and myopia in Chinese subjects

PURPOSE

To examine the relationship between corneal biomechanical properties and the degree of myopia.

METHODS

Chinese subjects (n=172, age: 11-65 years) were divided into diagnostic groups with non-myopia (spherical equivalence (SE)>-0.50 D), low (-3.00 ≤ SE ≤ -0.50 D), moderate (-6.00 ≤ SE < -3.00 D), and high myopia (SE<-6.00 D). Only the right eye of each subject was analyzed. Central corneal thickness (CCT) was measured by optical coherence tomography. An ocular response analyzer was used to measure corneal hysteresis (CH), corneal resistance factor (CRF), intraocular pressure (IOP), and corneal compensated IOP (IOPcc). Refraction was measured by both automated and subjective refractometry and expressed as SE.

RESULTS

CH was significantly lower in high myopia compared with both low and non-myopia (P ≤ 0.002). CCT was 1.5 times more correlated to CH variation compared with refraction. Similarly, CRF was four times more dependent on CCT than refraction. CH (P<0.001) or CRF (P=0.005) was positively correlated to refraction. Both IOP and IOPcc were negatively correlated to refraction (P<0.001), respectively.

CONCLUSIONS

CH decreases only in high myopia. Refraction is positively correlated to both CH and CRF but negatively correlated to both IOP and IOPcc. These results indicate that the mechanical strength in anterior segment of the eye is compromised in high myopia. In addition, high myopia may increase the risk of glaucoma.

Effects of Merogel coverage on wound healing and ostial patency in endonasal endoscopic dacryocystorhinostomy for primary chronic dacryocystitis

PURPOSE

To investigate the effects of Merogel coverage on ostial patency in endonasal endoscopic dacryocystorhinostomy (EES-DCR) for primary chronic dacryocystitis (PCD).

METHODS

In all, 260 patients with unilateral PCD were randomized into two groups: the Merogel group and the control group. All patients underwent EES-DCR. The Merogel group received Merogel covering the wound 1-2 mm around the ostium and the control group received no treatment. Patients were followed up for 9 months. The mucosal epithelialization of the wound, the proliferation of fibrosis tissue, and the success rate of ostial patency were compared.

RESULTS

Our study included 112 patients in the Merogel group and 115 patients in the control group. At the 2-week review, intact mucosal epithelium lined the ostia in 96 Merogel patients compared with 80 control patients (ITT analysis: χ(2)=4.502, P=0.034). At the 9-month review, scars were present in 18 patients in the Merogel group compared with 39 patients in the control group (ITT analysis: χ(2)=9.909, P=0.002, ITT analysis). No differences were observed in the granulation formation between the two groups. The success rate of ostial patency reached 94.6% (106/112) in the Merogel group compared with 80% (92/115) in the control group (ITT analysis: χ(2)=4.151, P=0.042).

CONCLUSION

Merogel coverage may enhance the success rate of EES-DCR for PCD by promoting mucosal epithelial healing and preventing excessive scarring.

Lower Temperature Plasticizing and Extrusion of Polymer in Spherical Screw Extruder under Vibration Force Field

Physical and mathematical model for polymer plasticizing in proposed electromagnetic dynamic spherical screw extruder were developed to explore polymer plasticizing and molding mechanism at lower temperature under vibration force field. Polymer plasticizing mechanism was studied by deriving the mathematical expressions of energy consumed and the polymer flow. The energy consumed in polymer plasticizing was depicted in terms of vibrating dissipation, polymer deformation, shear and friction energy. LDPE was used as an objective material and extruded by the extruder with the electromagnetic excitation and spherical screw. The experimental results show the good agreement with theoretical calculations. Both of them show that: Polymer processing temperature and energy consumption decrease significantly while the plasticizing rate is increased over 60% by introducing the vibration force field. The research offers experimental and theoretical references as well as the evaluation method for optimizing the polymer processing parameters and designing the vibration induced equipment.

Containment wells to form hydraulic barriers along site boundaries

In the field, aquifer remediation methods include pump and treat procedures based on hydraulic control systems. They are used to reduce the level of residual contamination present in the soil and soil pores of aquifers. Often, physical barriers are erected along the boundaries of the target (aquifer) site to reduce the leakage of the released soil contaminant to the surrounding regions. Physical barriers are expensive to build and dismantle. Alternatively, based on simple hydraulic principles, containment wells or image wells injecting clear water can be designed and built to provide hydraulic barriers along the contaminated site boundaries. For brevity, only one pattern of containment well system that is very effective is presented in detail. The study briefly reports about the method of erecting a hydraulic barrier around a contaminated region based on the simple hydraulic principle of images. During the clean-up period, hydraulic barriers can considerably reduce the leakage of the released contaminant from the target site to surrounding pristine regions. Containment wells facilitate the formation of hydraulic barriers. Hence, they control the movement of contaminants away from the site that is being remedied. However, these wells come into play, only when the pumping operation for cleaning up the site is active. After operation, they can be filled with soil to permit the natural ground water movement. They can also be used as monitoring wells.

Incorporation of outer membrane protein OmpG in lipid membranes: protein-lipid interactions and beta-barrel orientation

OmpG is an intermediate size, monomeric, outer membrane protein from Escherichia coli, with n beta = 14 beta-strands. It has a large pore that is amenable to modification by protein engineering. The stoichiometry ( N b = 20) and selectivity ( K r = 0.7-1.2) of lipid-protein interaction with OmpG incorporated in dimyristoyl phosphatidylcholine bilayer membranes was determined with various 14-position spin-labeled lipids by using EPR spectroscopy. The limited selectivity for different lipid species is consistent with the disposition of charged residues in the protein. The conformation and orientation (beta-strand tilt and beta-barrel order parameters) of OmpG in disaturated phosphatidylcholines of odd and even chain lengths from C(12:0) to C(17:0) was determined from polarized infrared spectroscopy of the amide I and amide II bands. A discontinuity in the protein orientation (deduced from the beta-barrel order parameters) is observed at the point of hydrophobic matching of the protein with lipid chain length. Compared with smaller (OmpA; n beta = 8) and larger (FhuA; n beta = 22) monomeric E. coli outer membrane proteins, the stoichiometry of motionally restricted lipids increases linearly with the number of beta-strands, the tilt (beta approximately 44 degrees ) of the beta-strands is comparable for the three proteins, and the order parameter of the beta-barrel increases regularly with n beta. These systematic features of the integration of monomeric beta-barrel proteins in lipid membranes could be useful for characterizing outer membrane proteins of unknown structure.

Mesenchymal stem cell-based angiopoietin-1 gene therapy for acute lung injury induced by lipopolysaccharide in mice

Bone marrow-derived mesenchymal stem cells (MSCs) can serve as a vehicle for gene therapy. Angiopoietin-1 (Ang1) is a critical factor for endothelial survival and vascular stabilization via the inhibition of endothelial permeability and leukocyte-endothelium interactions. We hypothesized that MSC-based Ang1 gene therapy might be a potential therapeutic approach for lipopolysaccharide (LPS)-induced lung injury. MSCs were isolated from 6 week-old inbred male mice and transduced with the Ang1 gene, using a lentivirus vector. The MSCs showed no significant phenotypic changes after transduction. In the in vivo mouse model, the LPS-induced lung injury was markedly alleviated in the group treated with MSCs carrying Ang1 (MSCs-Ang1), compared with groups treated with MSCs or Ang1 alone. The expression of Ang1 protein in the recipient lungs was increased after MSCs-Ang1 administration. The histopathological and biochemical indices of LPS-induced lung injury were improved after MSCs-based Ang1 gene treatment. MSCs-Ang1 administration also reduced pulmonary vascular endothelial permeability and the recruitment of inflammatory cells into the lung. Cells of MSC origin could be detected in the recipient lungs for 2 weeks after injection with MSCs. These results suggest that MSCs and Ang1 have a synergistic role in the treatment of LPS-induced lung injury. MSC-based Ang1 gene therapy may be developed as a potential novel strategy for the treatment of acute lung injury.

Tribo-mechanical properties of thin boron coatings deposited on polished cobalt alloy surfaces for orthopedic applications

This paper presents experimental evidence that thin (< approximately 200 nm) boron coatings, deposited with a (vacuum) cathodic arc technique on pre-polished Co-Cr-Mo surfaces, could potentially extend the life of metal-on-polymer orthopedic devices using cast Co-Cr-Mo alloy for the metal component. The primary tribological test used a linear, reciprocating pin-on-disc arrangement, with pins made of ultra-high molecular weight polyethylene. The disks were cast Co-Cr-Mo samples that were metallographically polished and then coated with boron at a substrate bias of 500 V and at about 100 degrees C. The wear tests were carried out in a saline solution to simulate the biological environment. The improvements were manifested by the absence of a detectable wear track scar on the coated metal component, while significant polymer transfer film was detected on the uncoated (control) samples tested under the same conditions. The polymer transfer track was characterized with both profilometry and Rutherford Backscattering Spectroscopy. Mechanical characterization of the thin films included nano-indentation, as well as additional pin-on-disk tests with a steel ball to demonstrate adhesion, using ultra-high frequency acoustic microscopy to probe for any void occurrence at the coating-substrate interface.

Airway hyperresponsiveness induced by repetitive intraperitoneal injection of lipopolysacharide and the involvement of inflammation and nitric oxide in guinea pigs

OBJECTIVE

Airway hyperresponsiveness (AHR) is involved in bronchial asthma and chronic obstructive pulmonary disease (COPD) and produces respiratory symptoms. Lipopolysaccharide (LPS) has been found to be significantly related to the severity of asthma. However, its clinical mechanism still remains controversial. This study investigated the in vivo effect of repetitive intraperitoneal administration of lipopolysaccharide (LPS) on airway hyperresponsiveness (AHR) in guinea pigs and the possible involvement of inflammation, nitric oxide (NO) and nitric oxide synthase (NOS).

METHODS

There were two exposure groups for intraperitoneal LPS injection: (1) LPS was given at a dose of 1 mg x kg(-1), followed by sterile saline (NS) 1 ml x kg(-1) 8 h later every 24 h; (2) LPS was given at a dose of 0.5 mg x kg(-1) two times with an interval of 8 h every 24 h. Each exposure regime was repeated 4 times. Control animals were given NS and 6 naive guinea pigs were used as baseline control. Determinations were made 24 h after each exposure.

RESULTS

Persistent AHR occurred 24 h after the third and fourth exposures to LPS in the first exposure group (at one dose), but occurred earlier after the exposures to LPS in the second exposure group (at divided doses). The numbers of total cells and neutrophils were elevated initially but subsided subsequently in LPS-treated groups. No evidence of morphological changes in the small airways was found 24 h after any of the exposures. The Ca(2+)-dependent and Ca(2+)-independent NOS activities (mainly produced by iNOS) in the BALF, as well as the production of NO, were significantly elevated 24 h after any of third and fourth exposures in LPS-treated groups.

CONCLUSIONS

Our results demonstrate that repetitive intraperitoneal LPS can induce persistent AHR which occurs earlier when the frequency of injection increase, and an elevation of NO production and iNOS activity may be involved in is systemic-LPS-induced AHR.

Transient overexpression of gamma interferon promotes Aspergillus clearance in invasive pulmonary aspergillosis

Cytokines are critical molecules necessary for normal lung pathogen host defences. Gamma interferon (IFN-gamma) and T1-phenotype immune responses are important components of host defence against Aspergillus. Therefore, we hypothesized that transient overexpression of IFN-gamma within the lung could augment host immunity against Aspergillus. Here it was showed that intranasal administration of 5 x 10(7) colony-forming units (CFU) of Aspergillus fumigatus (Af ) induced the expression of IFN-gamma. Mice were intranasally (i.n) administrated with 5 x 10(8) PFU of a recombinant adenovirus vector containing the murine IFN-gamma cDNA (AdmIFN-gamma), and challenged 24 h later with Af. We observed that i.n. administration of AdmIFN-gamma resulted in about a fourfold increase in levels of IFN-gamma and IL-12 within the lung, about a 75% reduction in lung fungal contents at day 2 and a more than threefold higher survival rate in the AdmIFN-gamma-treated group compared to the controls (P < 0.01). This protection effect was not found when AdmIFN-gamma was i.p. administrated. Alveolar macrophages and lung leucocytes isolated from i.n. AdmIFN-gamma-treated animals displayed enhanced killing of intracellular Aspergillus organisms ex vivo. These results demonstrate that transient overexpression of IFN-gamma could augment host defence against Aspergillus.

Dendritic cells transduced with an adenovirus vector encoding interleukin-12 are a potent vaccine for invasive pulmonary aspergillosis

Invasive pulmonary aspergillosis (IPA) is a common and devastating pneumonia. We developed a novel antiinfective vaccine that couples the potent Ag-presenting capacity of dendritic cells (DCs) with paracrine delivery of interleukin-12 (IL-12) to local immune response sites. Our results showed that DCs engulfed Aspergillus conidia through coiling phagocytosis. Transfection of DCs with adenovirus encoding the cDNA of IL-12 did not affect their morphology and capacity to engulf conidia. The transduced DCs secreted IL-12, which was biologically active, to induce the production of gamma interferon (IFN-gamma) from spleen cells. Adoptive transfer of DCs pulsed with heat-inactivated Aspergillus fumigatus (HAF) to naive mice induced the Ag-specific production of IFN-gamma; the transduced HAF-pulsed DCs augmented this immune response further. Animals receiving HAF-pulsed DCs had lower fungal burdens, a more than three-fold higher survival rate at day 3. This protection was associated with a pronounced enhancement in the Aspergillus-specific IFN-gamma response. IL-12-engineered DCs augmented this protection strikingly as judged by a higher survival, and almost no Aspergillus could be detected in the lung of mice that had received IL-12-transduced HAF-pulsed DCs. These results suggest that antigen-pulsed DCs and IL-12 gene therapy could be used as adjunct therapy for aspergillosis.

Endotoxin tlerance inhibits lipopolysaccharide-initiated acute pulmonary inflammation and lung injury in rats by the mechanism of nuclear factor-kappaB

In this study, the effect of endotoxin tolerance on lipopolysaccharide (LPS)-initiated pulmonary inflammation, the local production of tumour necrosis factor-alpha (TNF-alpha) and the cytokine-induced neutrophil attractant (CINC), as well as the activation of nuclear factor-kappaB (NF-kappaB) and its subunit composition, were examined in vivo. Endotoxin tolerance was reproduced by four consecutive daily intraperitoneal injections of 0.6 mg/kg of Escherichia coli 055:B5 LPS. Compared with control rats, endotoxin-tolerant rats failed to increase the permeability of pulmonary microvascular or recruit neutrophil to lung tissue upon restimulation with 6 mg/kg of LPSs. Pretreatment with LPSs inhibited the protein level of TNF-alpha in bronchoalveolar lavage fluid (BALF) and mRNA expression of CINC in lung tissue in response to subsequent LPS stimulation. These changes were accompanied by the suppression of activation of NF-kappaB, including the low level of total amount of DNA-binding activity and high percentage of non-transactive p50 homodimers. These data demonstrate that endotoxin tolerance can alleviate the LPS-induced acute neutrophilic pulmonary inflammation in rats and can inhibit the proinflammatory cytokines in lung and suggest that endotoxin tolerance might result from the unresponsiveness of NF-kappaB and persistent high percentage of p50 homodimers. Therefore, the phenomenon of endotoxin tolerance might be used as a strategy for the prevention or treatment of LPS-associated acute respiratory distress syndrome in which excessive or dysregulated inflammation leads to acute lung injury.

[Establishment and identification of the monoepitopic monoclonal antibody of Plasmodium falciparum]

AIM

To prepare a monoepitopic monclonal antibody of Plasmoduim falciparum.

METHODS

According to the theory of protein structure, a peptide with 6-9 residues representting the antigenicity of the original histidine-rich protein II (HRP-II) of P. falciparum was synthesized and used to immunize BALB/c mice after purity identification by capillary electrophoresis.

RESULTS

Four hybridoma cell lines targeting a suitable peptide from pf HRP-II were obtained by using spleen embedment method and hybridoma technology.

CONCLUSION

It is the first report to prepare a monoepitopic monoclonal antibody against original protein by selecting a suitable peptide from the primary sequence of protein.

[Diagnosis of Falciparum malaria by immunochromatographic test]

AIM

To evaluate the applicability of rapid immunochromatographic test(ICT) for diagnosing falciparum malaria in outpatient clinics in endemic area.

METHODS

With thick blood smear method as control, ICT was used for the detection of P. falciparum.

RESULTS

The sensitivity and specificity of ICT in detecting P. falciparum was 94.7% and 90.3%, respectively. No cross-reaction with P. vivax was found (P > 0.05).

CONCLUSION

ICT is much more rapid and simple than thick blood smear method for the diagnosis of falciparum malaria, and can be applied in the outpatient clinics in endemic area.

Ischemia alters the electrical activity of pacemaker cells isolated from the rabbit sinoatrial node

The purpose of this study was to investigate the mechanisms responsible for ischemia-induced changes in spontaneous electrical activity. An ischemic-like Tyrode solution (pH 6.6) reversibly depolarized the maximum diastolic potential (MDP) and reduced the action potential (AP) overshoot (OS). We used SNARF-1, which is an indicator of intracellular pH (pH(i)), and perforated-patch techniques to test the hypothesis that acidosis caused these effects. Acidic but otherwise normal Tyrode solution (pH 6.8) produced similar effects. Basic Tyrode solution (pH 8.5) hyperpolarized the MDP, shortened the AP, and slowed the firing rate. In the presence of "ischemic" Tyrode solution, hyperpolarizing current restored the MDP and OS to control values. HOE-642, an inhibitor of Na/H exchange, did not alter pH(i) or electrical activity and did not prevent the effects of ischemic Tyrode solution or recovery after washout. Time-independent net inward current but not hyperpolarization-activated inward current was enhanced by ischemic Tyrode solution or by 30 microM BaCl(2), a selective blocker of inward-rectifying K currents at this concentration. The results suggest that 1) acidosis was responsible for the ischemia-induced effects but Na/H exchange was not involved, 2) the OS was reduced because of depolarization-induced inactivation of inward currents that generate the AP upstroke, and 3) reduction of an inward-rectifying outward K current contributed to the depolarization.

Insight into hepatocellular carcinogenesis at transcriptome level by comparing gene expression profiles of hepatocellular carcinoma with those of corresponding noncancerous liver

Human hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. In this work, we report on a comprehensive characterization of gene expression profiles of hepatitis B virus-positive HCC through the generation of a large set of 5'-read expressed sequence tag (EST) clusters (11,065 in total) from HCC and noncancerous liver samples, which then were applied to a cDNA microarray system containing 12,393 genes/ESTs and to comparison with a public database. The commercial cDNA microarray, which contains 1,176 known genes related to oncogenesis, was used also for profiling gene expression. Integrated data from the above approaches identified 2,253 genes/ESTs as candidates with differential expression. A number of genes related to oncogenesis and hepatic function/differentiation were selected for further semiquantitative reverse transcriptase-PCR analysis in 29 paired HCC/noncancerous liver samples. Many genes involved in cell cycle regulation such as cyclins, cyclin-dependent kinases, and cell cycle negative regulators were deregulated in most patients with HCC. Aberrant expression of the Wnt-beta-catenin pathway and enzymes for DNA replication also could contribute to the pathogenesis of HCC. The alteration of transcription levels was noted in a large number of genes implicated in metabolism, whereas a profile change of others might represent a status of dedifferentiation of the malignant hepatocytes, both considered as potential markers of diagnostic value. Notably, the altered transcriptome profiles in HCC could be correlated to a number of chromosome regions with amplification or loss of heterozygosity, providing one of the underlying causes of the transcription anomaly of HCC.

Synthesis and characterization of chiral N-O turns induced by alpha-aminoxy acids

Chiral alpha-aminoxy acids of various side chains were synthesized with high optical purity starting from chiral alpha-amino acids. The conformations of diamides 13a-e, 15, and 16 were probed by using NMR, FT-IR, and CD spectroscopic methods as well as X-ray crystallography. The right-handed turns with eight-membered-ring intramolecular hydrogen bonds between adjacent residues (called the N-O turns) were found to be preferred for D-aminoxy acid residues, and they were independent of the side chains. The rigid chiral N-O turns should have great potential in molecular design.

Alteration of surfactant proteins A and D in bronchoalveolar lavage fluid of Pneumocystis carinii pneumonia

OBJECTIVE

To understand the interaction between surfactant proteins and pneumocystis carinii pneumonia (PCP), and the impact of corticosteriods on surfactant proteins.

METHODS

We established rat models of PCP and bacterial pneumonia induced by subcutaneous injection of 25 mg cortisone acetate. At 8-12 wk, the bronchoalveolar lavage fluid (BALF) of rats was collected. Total nucleated cells of BALF were counted and differentiated, and the concentrations of surfactant protein A (SP-A) and surfactant protein D (SP-D) were measured by immunoblotting assay. The rats were divided into three immunosuppressive groups and a normal control group. Group I, normal control (n = 6), consisted of healthy SD rats; group II, negative control (n = 6), consisted of rats with cortisone acetate injection for over 8 wk without lung infection; group III, bacterial pneumonia (n = 11), rats were injected with cortisone acetate over 8 wk that resulted in bacterial pneumonia without other pathogens isolated; and group IV, PCP (n = 14), rats with injected cortisone acetate for 8-12 wk and developed PCP without other pathogens isolated.

RESULTS

Our results indicated that the total cell count in BALF in the negative control group was lower than that in the normal control group (P < 0.001). During PCP infection, the total cell count and the percentage of polymorphonuclearcytes (PMNs) in BALF were significantly increased (P < 0.01), but were lower than those in the bacterial pneumonia group. The concentration of SP-A of BALF in PCP (45.1 +/- 22.1 micrograms/ml) was significantly increased in comparison with that in the negative control (16.2 +/- 9.9 micrograms/ml, P < 0.05) and bacterial pneumonia groups (6.2 +/- 5.6 micrograms/ml, P < 0.001). We also found that the relative content of SP-D was significantly higher in PCP (24,249 +/- 4780 grey values) than that in the negative control (13,384 +/- 2887 grey values, P < 0.001) and that in bacterial pneumonia (11,989 +/- 2750 grey values, P < 0.001). SP-A and SP-D were also higher in the moderate to heavy group of PCP than those seen in the mild group (P < 0.01, P < 0.001). SP-A and SP-D were higher in the negative control group than those in the normal control group, but there was no significant difference between the 2 groups.

CONCLUSION

These results suggest that the concentrations of SP-A and SP-D in BALF are increased by pneumocystis carinii specific stimulation, but the alteration is not related to the corticosteriod usage.