Technology Resource,Distribution, and Development Characteristics of Global Influenza Virus Vaccine: A Patent Bibliometric Analysis

Influenza virus vaccine (IVV) is a promising research domain that is closely related to global health matters, which has been acknowledged not only by scientists and technology developers, but also by policy-makers. Meanwhile, patents encompass valuable technological information and reflect the latest technological inventions as well as the innovative capability of a nation. However, little research has examined this up-and-coming research field using patent bibliometric method. Thus, this paper (a) designs the technology classification system and search strategy for the identification of IVV; and (b) presents a longitudinal analysis of the global IVV development based on the European Patent Office (EPO) patents. Bibliometric analysis is used to rank countries, institutions, inventors and technology subfields contributing to IVV technical progress. The results show that the global trends of IVV are a multi-developing feature of variety but an uneven technical resource distribution. Although the synthetic peptide vaccine is a comparatively young field, it already demonstrates the powerful vitality and the enormous development space. With the worldwide competition increasing, all nations especially China should be looking to increase devotion, enhance capability and regard effectiveness of technological innovation.     

Interaction of sortase A and lipase 2 in the inhibition of <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> biofilm formation

Recombinant sortase A (SrtA) was used to immune rabbit, and the inhibitory activity of anti-SrtA serum on Staphylococcus aureus biofilm formation was tested. Biofilm formation was inhibited by anti-SrtA rabbit serum in S. aureus ATCC25923 and two clinical isolated strains. The antiserum was separated into two fractions, and the main component with the inhibitory activity was demonstrated to be the IgG fraction. Two proteins interact with the IgG fraction were identified by using an in vitro pull-down assay and were confirmed to be lipase 2 and γ-hemolysin by mass spectrometry. Cross-interaction between SrtA and lipase 2 was further confirmed by Western blotting. Addition of anti-lipase 2 serum in the culture medium also showed inhibitory effect against biofilm formation. Together, our study suggests anti-SrtA serum inhibits S. aureus biofilm formation and lipase 2 is one of the targets of anti-SrtA serum in this inhibition process. This is the first study to demonstrate the roles of antisera against SrtA and lipase 2 in the inhibition of biofilm formation in S. aureus.     

Quantitative Surface-Enhanced Raman for Gene Expression Estimation

We demonstrate for the first time, to our knowledge, a unique gene expression assay by surface-enhanced Raman scattering (SERS) using nonfluorescent Raman labels to quantify gene expression at the resolution of alternative splicing using RNA extracted from cancer cells without any amplification steps. Our approach capitalizes on the inherent plasmon-phonon mode of SERS substrates as a self-referencing standard for the detection and quantification of genetic materials. A strategy integrating S1 nuclease digestion with SERS detection was developed to quantify the expression levels of splice junction Δ(9,10), a segment of the breast cancer susceptibility gene 1 (BRCA1) from MCF-7 and MDA-MB-231 cells. Quantification results were cross-validated using two Raman tags and qualitatively confirmed by RT-PCR. Our methodology based on SERS technology provides reliable gene expression data with high sensitivity, bypassing the intricacies involved in fabricating a consistent SERS substrate.     

A cell permeable peptide analog as a potential-specific PET imaging probe for prostate cancer detection

Non-invasive detection of prostate cancer or metastases still remains a challenge in the field of molecular imaging. In our recent work of screening arginine- or lysine-rich peptides for intracellular delivery of a therapeutic agent into prostate cancer cells, an arginine-rich cell permeable peptide (NH₂GR₁₁) was found with an unexpectedly preferential uptake in prostate cancer cell lines. The goal of this work was to develop this peptide as a positron emission tomography (PET) imaging probe for specific detection of distant prostate cancer metastases. The optimal length of arginine-rich peptides was evaluated by the cell uptake efficiency of three fluorescein isothiocyanate (FITC)-tagged oligoarginines (NHGR₉, NHGR₁₁, and NHGR₁₃) in four human prostate cell lines (LNCaP, PZ-HPV-7, DU145, and PC3). Of the three oligoarginines, NH₂GR₁₁ showed the highest cell uptake and internalization efficiency with its subcellular localization in cytosol. The biodistribution of FITC-NHGR₉, FITC-NHGR₁₁, and FITC-NHGR₁₃ performed in control nude mice displayed the unique preferential accumulation of FITC-NHGR₁₁ in the prostate tissue. Further in vivo evaluation of FITC-NHGR₁₁ in PC3 tumor-bearing nude mice revealed elevated uptake of this peptide in tumors as compared to other organs. In vivo pharmacokinetics evaluated with ⁶⁴Cu-labeled NH₂GR₁₁ showed that the peptide was rapidly cleared from the blood (t _1/2 = 10.7 min) and its elimination half-life was 17.2 h. The PET imaging specificity of ⁶⁴Cu-labled NH₂GR₁₁ was demonstrated for the detection of prostate cancer in a comparative imaging experiment using two different human cancer xenograft models.     

Exogenous gibberellic acid increases the fruit weight of ‘Comte de Paris’ pineapple by enlarging flesh cells without negative effects on fruit quality

In mainland China, the most popular pineapple cultivar is ‘Comte de Paris’. Gibberellic acids have been widely applied to enhance fruit growth in various species. To evaluate the effect of gibberellic acid (GA₃) on ‘Comte de Paris’ pineapple production and quality, pineapple fruits were sprayed with GA₃ at concentrations of 5, 20, 50, or 100 mg l⁻¹ at both 0 and 15 days after flowering (DAF). Fruits were sampled every 15 days from 0 to 60 DAF (maturation) for flow cytometric analysis and histological observation. The results showed that the treatments with the three highest concentrations of GA₃ significantly increased fruit weight, and the most effective concentration was 50 mg l⁻¹ GA₃, which increased the flesh weight by 20.3% compared to the control. Although treatment with GA₃ had little effect on the total soluble solids and fruit juice pH, it increased the vitamin C content. Although flow cytometric analysis showed that the 50 mg l⁻¹ GA₃ treatment had only a slight impact on the number of S phase cells, histological observations indicated that the increase of fruit volume and flesh weight under this GA₃ treatment was not due to the increase of cell number but a result of the increase of cell area in the fruit flesh.     

Enrichment of a common wheat genetic map and QTL mapping for fatty acid content in grain

DArT and SSR markers were used to saturate and improve a previous genetic map of RILs derived from the cross Chuan35050 × Shannong483. The new map comprised 719 loci, 561 of which were located on specific chromosomes, giving a total map length of 4008.4 cM; the rest 158 loci were mapped to the most likely intervals. The average chromosome length was 190.9 cM and the marker density was 7.15 cM per marker interval. Among the 719 loci, the majority of marker loci were DArTs (361); the rest included 170 SSRs, 100 EST-SSRs, and 88 other molecular and biochemical loci. QTL mapping for fatty acid content in wheat grain was conducted in this study. Forty QTLs were detected in different environments, with single QTL explaining 3.6-58.1% of the phenotypic variations. These QTLs were distributed on 16 chromosomes. Twenty-two QTLs showed positive additive effects, with Chuan35050 increasing the QTL effects, whereas 18 QTLs were negative with increasing effects from Shannong483. Six sets of co-located QTLs for different traits occurred on chromosomes 1B, 1D, 2D, 5D, and 6B.     

Single-particle reconstruction using L(2)-gradient flow

In this paper, we present an iterative algorithm for reconstructing a three-dimensional density function from a set of two dimensional electron microscopy images. By minimizing an energy functional consisting of a fidelity term and a regularization term, an L²-gradient flow is derived. The flow is integrated by a finite element method in the spatial direction and an explicit Euler scheme in the temporal direction. Our method compares favorably with those of the weighted back projection, Fourier method, algebraic reconstruction technique and simultaneous iterative reconstruction technique.     

Novel nucleotide and amino acid covariation between the 5'UTR and the NS2/NS3 proteins of hepatitis C virus: bioinformatic and functional analyses

Molecular covariation of highly polymorphic viruses is thought to have crucial effects on viral replication and fitness. This study employs association rule data mining of hepatitis C virus (HCV) sequences to search for specific evolutionary covariation and then tests functional relevance on HCV replication. Data mining is performed between nucleotides in the untranslated regions 5' and 3'UTR, and the amino acid residues in the non-structural proteins NS2, NS3 and NS5B. Results indicate covariance of the 243(rd) nucleotide of the 5'UTR with the 14(th), 41(st), 76(th), 110(th), 211(th) and 212(th) residues of NS2 and with the 71(st), 175(th) and 621(st) residues of NS3. Real-time experiments using an HCV subgenomic system to quantify viral replication confirm replication regulation for each covariant pair between 5'UTR??? and NS2-41, -76, -110, -211, and NS3-71, -175. The HCV subgenomic system with/without the NS2 region shows that regulatory effects vanish without NS2, so replicative modulation mediated by HCV 5'UTR??? depends on NS2. Strong binding of the NS2 variants to HCV RNA correlates with reduced HCV replication whereas weak binding correlates with restoration of HCV replication efficiency, as determined by RNA-protein immunoprecipitation assay band intensity. The dominant haplotype 5'UTR???-NS2-41-76-110-211-NS3-71-175 differs according to the HCV genotype: G-Ile-Ile-Ile-Gly-Ile-Met for genotype 1b and A-Leu-Val-Leu-Ser-Val-Leu for genotypes 1a, 2a and 2b. In conclusion, 5'UTR??? co-varies with specific NS2/3 protein amino acid residues, which may have significant structural and functional consequences for HCV replication. This unreported mechanism involving HCV replication possibly can be exploited in the development of advanced anti-HCV medication.     

Epigenetic mechanism underlying the development of polycystic ovary syndrome (PCOS)-like phenotypes in prenatally androgenized rhesus monkeys

The pathogenesis of polycystic ovary syndrome (PCOS) is poorly understood. PCOS-like phenotypes are produced by prenatal androgenization (PA) of female rhesus monkeys. We hypothesize that perturbation of the epigenome, through altered DNA methylation, is one of the mechanisms whereby PA reprograms monkeys to develop PCOS. Infant and adult visceral adipose tissues (VAT) harvested from 15 PA and 10 control monkeys were studied. Bisulfite treated samples were subjected to genome-wide CpG methylation analysis, designed to simultaneously measure methylation levels at 27,578 CpG sites. Analysis was carried out using Bayesian Classification with Singular Value Decomposition (BCSVD), testing all probes simultaneously in a single test. Stringent criteria were then applied to filter out invalid probes due to sequence dissimilarities between human probes and monkey DNA, and then mapped to the rhesus genome. This yielded differentially methylated loci between PA and control monkeys, 163 in infant VAT, and 325 in adult VAT (BCSVD P<0.05). Among these two sets of genes, we identified several significant pathways, including the antiproliferative role of TOB in T cell signaling and transforming growth factor-β (TGF-β) signaling. Our results suggest PA may modify DNA methylation patterns in both infant and adult VAT. This pilot study suggests that excess fetal androgen exposure in female nonhuman primates may predispose to PCOS via alteration of the epigenome, providing a novel avenue to understand PCOS in humans.     

Derivation and characterization of ovine embryonic stem-like cell lines in semi-defined medium without feeder cells

Domestic animal embryonic stem (ES) cells would provide an invaluable research tool for genetic breeding and the production of transgenic animals. Unfortunately, authentic domestic animals ES cells have not been established despite progress made over more than two decades. Here, we show that ovine ES-like cells can be efficiently derived and propagated in a semi-defined medium that contains N2, B27, GSK3 inhibitor (CHIR99021), and basic fibroblast growth factor (bFGF). These ovine ES-like cells had a characteristic three-dimensional appearance, showed a bFGF dose-dependence, expressed specific markers such as alkaline phosphatase (AP), Oct-4, Sox2, Nanog and can be maintained for 30 passages. Moreover, these cells differentiated in vitro into neuronal cells, and formed teratomas containing a variety of different tissues including cartilage and neural tissue when injected into kidney capsules of severe combined immunodeficiency (SCID) mice. But the cell lines fail to contribute to embryonic development upon blastocyst transplantation. To our knowledge, this is the first experiment to use semi-defined medium without feeder-cells to derive ES-like cells from ovine blastocysts, and opens the door to deriving authentic ES cells from domesticated ungulates.