La-doped Porous Fe2O3 Nanorods as Advanced Anodes for Lithium/Sodium Ion Batteries and Sulfur Host for Li-Sulfur Batteries

Transition metal oxides are investigated as electrochemically active anodes for several years due to the merits of high specific capacity, low cost, abundant resources and controllable synthesis. But the poor cycle performances have hindered their further wide application. Herein, porous La-doped FeOOH nanorods have been synthesized through a facile hydrothermal method, which could be transformed into porous La-doped Fe2O3 (Fe2O3-La) via a simple heating process. Compared with the undoped Fe2O3, the Fe2O3-La showed larger surface area, higher specific capacities and more stable cycle performances for lithium/sodium ion batteries. In addition, as an advanced sulfur host for lithium-sulfur batteries, the Fe2O3-La also displayed much more excellent cycle and rate performances than the undoped Fe2O3. The superior electrochemical performances of the Fe2O3-La may could be attributed to the doping of La, which could induce more porous morphology and offer more reactive sites. The positive effects of La-doping for electrochemical performances of porous Fe2O3 nanorods provide novel insights for further applications of rare earth metal doping.

Role of regulatory non-coding RNAs in traumatic brain injury

Traumatic brain injury (TBI) is a potentially fatal health event that cannot be predicted in advance. After TBI occurs, it can have enduring consequences within both familial and social spheres. Yet, despite extensive efforts to improve medical interventions and tailor healthcare services, TBI still remains a major contributor to global disability and mortality rates. The prompt and accurate diagnosis of TBI in clinical contexts, coupled with the implementation of effective therapeutic strategies, remains an arduous challenge. However, a deeper understanding of changes in gene expression and the underlying molecular regulatory processes may alleviate this pressing issue. In recent years, the study of regulatory non-coding RNAs (ncRNAs), a diverse class of RNA molecules with regulatory functions, has been a potential game changer in TBI research. Notably, the identification of microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and other ncRNAs has revealed their potential as novel diagnostic biomarkers and therapeutic targets for TBI, owing to their ability to regulate the expression of numerous genes. In this review, we seek to provide a comprehensive overview of the functions of regulatory ncRNAs in TBI. We also summarize regulatory ncRNAs used for treatment in animal models, as well as miRNAs, lncRNAs, and circRNAs that served as biomarkers for TBI diagnosis and prognosis. Finally, we discuss future challenges and prospects in diagnosing and treating TBI patients in the clinical settings.

CD8 T cell-mediated depletion of HBV surface-antigen-expressing, bilineal-differentiated liver carcinoma cells generates highly aggressive escape variants

The expression of viral antigens in chronic hepatitis B virus (HBV) infection drives continuous liver inflammation, one of the main risk factors to develop liver cancer. HBV developed immune-suppressive functions to escape from the host immune system, but their link to liver tumor development is not well understood. Here, we analyzed if and how HBV surface antigen (HBs) expression in combined hepatocellular-cholangiocarcinoma (cHCC/iCCA) cells influences their antigenicity for CD8 T cells. We randomly isolated liver tumor tissues from AlfpCre+-Trp53fl/fl/Alb-HBs+ tg mice and established primary carcinoma cell lines (pCCL) that showed a bilineal (CK7+/HNF4α+) cHCC/iCCA phenotype. These pCCL uniformly expressed HBs (HBshi), and low levels of MHC-I (MHC-Ilo), and were transiently convertible to a high antigenicity (MHC-Ihi) phenotype by IFN-γ treatment. HBshi/pCCL induced HBs/(Kb/S190-197)-specific CD8 T cells and developed slow-growing tumors in subcutaneously transplanted C57Bl/6J (B6) mice. Interestingly, pCCL-ex cells, established from HBshi/pCCL-induced and re-explanted tumors in B6 but not those in immune-deficient Rag1-/- mice showed major alterations, like an MHC-Ihi phenotype, a prominent growth-biased gene expression signature, a significantly decreased HBs expression (HBslo) and a switch to fast-growing tumors in re-transplanted B6 or PD-1-/- hosts with an unlocked PD-1/PD-L1 control system. CD8 T cell-mediated elimination of HBshi/pCCL, together with the attenuation of the negative restraints of HBs in the tumor cells, like ER-stress, reveals a novel mechanism to unleash highly aggressive HBslo/pCCL-ex immune-escape variants. Under certain conditions, HBs-specific CD8 T-cell responses thus potentiate tumor growth, an aspect that should be considered for therapeutic vaccination strategies against chronic HBV infection and liver tumors.

Novel Carbazole-Based Porous Organic Polymer for Efficient Iodine Capture and Rhodamine B Adsorption

A new porous organic polymer (CTF-CAR), which takes carbazole as the electron-rich center unit and thiophenes as the auxiliary group, has been synthesized through catalyst-free Schiff-base polymerization. At the same time, the structure, thermal stability, morphology, and other basic properties of the polymer were analyzed by IR, NMR, TGA, and SEM. Then, CTF-CAR was applied to iodine capture and rhodamine B adsorption. Due to its strong electron donor ability and abundant heteroatom binding sites, which have a positive effect on the interaction between the polymer network and adsorbates, CTF-CAR exhibits high uptake capacities for iodine vapor and rhodamine B as 2.86 g g-1 and 199.7 mg g-1, respectively. The recyclability test also confirmed that it has good reusability. We found that this low-cost and catalyst-free synthetic porous organic polymer has great potential for the treatment of polluted water and iodine capture.

Influences of Separator Thickness and Surface Coating on Lithium Dendrite Growth: A Phase-Field Study

Li dendrite growth, which causes potential internal short circuit and reduces battery cycle life, is the main hazard to lithium metal batteries. Separators have the potential to suppress dendrite growth by regulating Li⁺ distribution without increasing battery weight significantly. However, the underlying mechanism is still not fully understood. In this paper, we apply an electrochemical phase-field model to investigate the influences of separator thickness and surface coating on dendrite growth. It is found that dendrite growth under thicker separators is relatively uniform and the average dendrite length is shorter since the ion concentration within thicker separators is more uniform. Moreover, compared to single layer separators, the electrodeposition morphology under particle-coated separators is smoother since the particles can effectively regulate Li ionic flux and homogenize Li deposition. This study provides significant guidance for designing separators that inhibit dendrites effectively.

Structural insights into ligand recognition and selectivity of somatostatin receptors

Somatostatin receptors (SSTRs) play versatile roles in inhibiting the secretion of multiple hormones such as growth hormone and thyroid-stimulating hormone, and thus are considered as targets for treating multiple tumors. Despite great progress made in therapeutic development against this diverse receptor family, drugs that target SSTRs still show limited efficacy with preferential binding affinity and conspicuous side-effects. Here, we report five structures of SSTR2 and SSTR4 in different states, including two crystal structures of SSTR2 in complex with a selective peptide antagonist and a non-peptide agonist, respectively, a cryo-electron microscopy (cryo-EM) structure of G_i1-bound SSTR2 in the presence of the endogenous ligand SST-14, as well as two cryo-EM structures of G_i1-bound SSTR4 in complex with SST-14 and a small-molecule agonist J-2156, respectively. By comparison of the SSTR structures in different states, molecular mechanisms of agonism and antagonism were illustrated. Together with computational and functional analyses, the key determinants responsible for ligand recognition and selectivity of different SSTR subtypes and multiform binding modes of peptide and non-peptide ligands were identified. Insights gained in this study will help uncover ligand selectivity of various SSTRs and accelerate the development of new molecules with better efficacy by targeting SSTRs.

Insulin resistance in school-aged girls with overweight and obesity is strongly associated with elevated white blood cell count and absolute neutrophil count

BACKGROUND

The primary objective of the study was to discuss the sex differences in insulin resistance-induced changes in metabolic and inflammatory markers in school-aged children with overweight and obesity.

METHODS

A cross-sectional study of 800 children aged seven and twelve years was performed. Questionnaires, anthropometric data and fasting blood samples were collected.

RESULTS

Children with overweight and obesity showed statistically significant differences in multiple metabolic and inflammatory markers compared with children with normal BMI. The correlation coefficient (r) between white blood cell count, absolute neutrophil count, fasting plasma insulin, HOMA-IR, HOMA-β, triglyceride, HDL-C, triglyceride/HDL ratio, alanine transaminase, serum uric acid, systolic blood pressure and BMI were higher in all children, but the linear relationships between white blood cell count, absolute neutrophil count and BMI were stronger in girls with overweight and obesity than in boys with overweight and obesity. Subsequently, HOMA-IR was shown to be more strongly associated with increased white blood cell count and absolute neutrophil count in school-aged girls with overweight and obesity by partial correlation analysis and the multiple linear regression analysis.

CONCLUSIONS

Elevated white blood cell count and absolute neutrophil count in children with overweight and obesity, especially girls, can serve as markers of insulin resistance.

A molybdenum oxide-based degradable nanosheet for combined chemo-photothermal therapy to improve tumor immunosuppression and suppress distant tumors and lung metastases

Molybdenum oxide (MoOx) nanosheets have drawn increasing attention for minimally invasive cancer treatments but still face great challenges, including complex modifications and the lack of efficient accumulation in tumor. In this work, a novel multifunctional degradable FA-BSA-PEG/MoOx nanosheet was fabricated (LA-PEG and FA-BSA dual modified MoOx): the synergistic effect of PEG and BSA endows the nanosheet with excellent stability and compatibility; the FA, a targeting ligand, facilitates the accumulation of nanosheets in the tumor. In addition, DTX, a model drug for breast cancer treatment, was loaded (76.49%, 1.5 times the carrier weight) in the nanosheets for in vitro and in vivo antitumor evaluation. The results revealed that the FA-BSA-PEG/MoOx@DTX nanosheets combined photothermal and chemotherapy could not only inhibit the primary tumor growth but also suppress the distant tumor growth (inhibition rate: 51.7%) and lung metastasis (inhibition rate: 93.6%), which is far more effective compared to the commercial Taxotere®. Exploration of the molecular mechanism showed that in vivo immune response induced an increase in positive immune responders, suppressed negative immune suppressors, and established an inflammatory tumor immune environment, which co-contributes towards effective suppression of tumor and lung metastasis. Our experiments demonstrated that this novel multifunctional nanosheet is a promising platform for combined chemo-photothermal therapy.

Nanotechnology for Boosting Cancer Immunotherapy and Remodeling Tumor Microenvironment: The Horizons in Cancer Treatment

Immunotherapy that harnesses the human immune system to fight cancer has received widespread attention and become a mainstream strategy for cancer treatment. Cancer immunotherapy not only eliminates primary tumors but also treats metastasis and recurrence, representing a major advantage over traditional cancer treatments. Recently with the development of nanotechnology, there exists much work applying nanomaterials to cancer immunotherapy on the basis of their excellent physiochemical properties, such as efficient tissue-specific delivery function, huge specific surface area, and controllable surface chemistry. Consequently, nanotechnology holds significant potential in improving the efficacy of cancer immunotherapy. Nanotechnology-based immunotherapy mainly manifests its inhibitory effect on tumors via two different approaches: one is to produce an effective anti-tumor immune response during tumorigenesis, and the other is to enhance tumor immune defense ability by modulating the immune suppression mechanism in the tumor microenvironment. With the success of tumor immunotherapy, understanding the interaction between the immune system and smart nanomedicine has provided vigorous vitality for the development of cancer treatment. This review highlights the application, progress, and prospect of nanomedicine in the process of tumor immunoediting and also discusses several engineering methods to improve the efficiency of tumor treatment.

RVG-functionalized reduction sensitive micelles for the effective accumulation of doxorubicin in brain

BACKGROUND

Glioblastoma is a lethal neoplasm with few effective therapy options. As a mainstay in the current treatment of glioma at present, chemotherapeutic agents usually show inadequate therapeutic efficiency due to their low blood brain barrier traversal and brain targeting, together with tumor multidrug resistance. Novel treatment strategies are thus urgently needed to improve chemotherapy outcomes.

RESULTS

Here, we report that nanomedicines developed by functionalizing the neurotropic rabies virus-derived polypeptide, RVG, and loading reduction-sensitive nanomicelles (polymer and doxorubicin) enable a highly specific and efficacious drug accumulation in the brain. Interestingly, curcumin serves as the hydrophobic core of the polymer, while suppressing the major efflux proteins in doxorubicin-resistant glioma cells. Studies on doxorubicin-resistant rat glioma cells demonstrate that the RVG-modified micelles exhibit superior cell entry and antitumor activity. In vivo research further showed that RVG modified nanomicelles significantly enhanced brain accumulation and tumor inhibition rate in mice, leading to a higher survival rate with negligible systemic toxicity. Moreover, effective suppression of recurrence and pulmonary metastatic nodules were also determined after the RVG-modified nanomicelles treatment.

CONCLUSIONS

The potential of RVG-modified nanomicelles for glioma was demonstrated. Brain accumulation was markedly enhanced after intravenous administration. This unique drug delivery nanoplatform to the brain provides a novel and powerful therapeutic strategy for the treatment of central nervous system disorders including glioma.

A review of stimuli-responsive polymeric micelles for tumor-targeted delivery of curcumin

Despite a potential drug with multiple pharmacological activities, curcumin has disadvantages of the poor water solubility, rapid metabolism, low bioavailability, which considerably limit its clinical application. Currently, polymeric micelles (PMs) have gained widespread concern due to their advantageous physical and chemical properties, easy preparation, and biocompatibility. They can be used to improve drug solubility, prolong blood circulation time, and allow passive targeted drug delivery to tumor through enhanced penetration and retention effect. Moreover, studies focused on tumor microenvironment offer alternatives to design stimulus-responsive smart PMs based on low pH, high levels of glutathione, altered enzyme expression, increased reactive oxygen species production, and hypoxia. There are various external stimuli, such as light, ultrasound, and temperature. These endogenous/exogenous stimuli can be used for the research of intelligent micelles. Intelligent PMs can effectively load curcumin with improved solubility, and intelligently respond to release the drug at a controlled rate at targeted sites such as tumors to avoid early release, which markedly improves the bioavailability of curcumin. The present review is aimed to discuss and summarize recent developments in research of curcumin-loaded intelligent PMs based on endogenous and exogenous stimuli, and facilitates the development of novel delivery systems for future research.

Oxygen-carrying nanoparticle-based chemo-sonodynamic therapy for tumor suppression and autoimmunity activation

Sonodynamic therapy (SDT) is a promising non-invasive approach for cancer therapy. However, tumor hypoxia, a pathological characteristic of most solid tumor types, poses a major challenge in the application of SDT. In this study, a novel CD44 receptor-targeted and redox/ultrasound-responsive oxygen-carrying nanoplatform was constructed using chondroitin sulfate (CS), reactive oxygen species (ROS)-generating sonosensitizer Rhein (Rh), and perfluorocarbon (PFC). Perfluoroalkyl groups introduced into the structures preserved the oxygen carrying ability of PFC, increasing the oxygen content in B16F10 melanoma cells and enhancing the efficiency of SDT. Controlled nanoparticles without PFC generated lower ROS levels and exerted inferior tumor inhibition effects, both in vitro and in vivo, under ultrasound-treatment. In addition, SDT promoted immunogenic cell death (ICD) by inducing exposure of calreticulin (CRT) after treatment with CS-Rh-PFC nanoparticles (NPs). The immune system was significantly activated by docetaxel (DTX)-loaded NPs after SDT treatment due to the enhanced secretion of IFN-γ, TNF-α, IL-2 and IL-6 cytokines and tumor-infiltrating CD4+ and CD8+ T cell contents. Our findings support the utility of CS-Rh-PFC as an effective anti-tumor nanoplatform that promotes general immunity and accommodates multiple hydrophobic drugs to enhance the beneficial effects of chemo-SDT therapy.

Sex-Specific Differences in Related Indicators of Blood Pressure in School-Age Children With Overweight and Obesity: A Cross-Sectional Study

Objective: The objective of this study is to further explore the difference between elevated blood pressure (EBP), elevated pulse pressure (EPP), and elevated mean arterial pressure (EMAP) and obesity in Chinese school-age children by sex. Methods: We performed a cross-sectional study of 935 children between 7 and 12 years old. Overweight and obesity were defined by body mass index and body composition. The multivariate logistic regression and the adjusted population attributable risk were used to assess the effects of obesity on pre-EBP/EBP, EPP, and EMAP. The interactions were used to identify the modification of obese on the relationship between related indicators of blood pressure and height or age. Results: The average age of the children included in the study was 10. Boys with overweight and obesity had higher pre-EBP/EBP, EPP, and EMAP (p < 0.05). The multivariate logistic regression analysis showed that overweight and obesity had a greater impact on BP and MAP than PP, especially in boys [odds ratio (OR) > 1]. Pre-EBP/EBP in 79% of boys and 76% of girls could be attributable to the visceral fat level. The interaction between BP, PP, MAP, and height or age was modestly increased in children with overweight and obesity, especially in boys. Conclusions: Independent of age and height, obesity not only increases blood pressure, it also increases mean arterial pressure and pulse pressure, and this effect is more pronounced in boys.

Sex differences in changes in BMI and blood pressure in Chinese school-aged children during the COVID-19 quarantine

There may be sex differences in BMI and blood pressure levels in school-age children, especially in the face of lifestyle changes. This study aimed to explore sex differences in changes in BMI and blood pressure in Chinese school-aged children during the COVID-19 quarantine. The cohort study of 445 school-aged children examined the change of BMI and blood pressure during the five-month quarantine. Multivariable Cox regression models were created to identify potential predictors of overweight, obesity, and elevated blood pressure (EBP). During the COVID-19 quarantine, the proportion of boys with overweight and obesity increased (P = 0.036), and the proportion of both boys and girls with Pre-EBP and EBP increased (P = 0.004 in boys; P < 0.001 in girls). The multivariate Cox regression analysis demonstrated that the setting, eating chili, parents' perception of their child's size and family doting were associated with overweight, obesity, and EBP. The study showed that BMI was more likely to increase in boys, and blood pressure increased in both boys and girls during the COVID-19 quarantine.

Chondroitin sulfate-based nanoparticles for enhanced chemo-photodynamic therapy overcoming multidrug resistance and lung metastasis of breast cancer

As a major therapeutic approach for cancer treatment, the effectiveness of chemotherapy is challenged by multidrug resistance (MDR). Herein, we fabricated novel redox-responsive, chondroitin sulfate-based nanoparticles that could simultaneously deliver quercetin (chemosensitizer), chlorin e6 (photosensitizer) and paclitaxel (chemotherapeutic agent) to exert enhanced chemo-photodynamic therapy for overcoming MDR and lung metastasis of breast cancer. In vitro cell study showed that nanoparticles down-regulated the expression of P-glycolprotein (P-gp) on MCF-7/ADR cells and thereby improved the anticancer efficacy of PTX against MCF-7/ADR cells. Moreover, NIR laser irradiation could induce nanoparticles to generate cellular reactive oxygen species (ROS), leading to mitochondrial membrane potential loss, and meanwhile facilitating lysosomal escape of drugs. Importantly, the novel nanoplatform exhibited effective in vivo MDR inhibition and anti-metastasis efficacy through enhanced chemo-photodynamic therapy. Thus, the study suggested that the multifunctional nanoplatform had good application prospect for effective breast cancer therapy.

Research Progress in Bioinspired Drug Delivery Systems

INTRODUCTION

To tackle challenges associated with traditional drug carriers, investigators have explored cells, cellular membrane, and macromolecular components including proteins and exosomes for the fabrication of delivery vehicles, owing to their excellent biocompatibility, lower toxicity, lower immunogenicity and similarities with the host. Biomacromolecule- and biomimetic nanoparticle (NP)-based drug/gene carriers are drawing immense attention, and biomimetic drug delivery systems (BDDSs) have been conceived and constructed.

AREAS COVERED

This review focuses on BDDS based on mammalian cells, including blood cells, cancer cells, adult stem cells, endogenous proteins, pathogens and extracellular vesicles (EVs).

EXPERT OPINION

Compared with traditional drug delivery systems (DDSs), BDDSs are based on biological nanocarriers, exhibiting superior biocompatibility, fewer side effects, natural targeting, and diverse modifications. In addition to directly employing natural biomaterials such as cells, proteins, pathogens and EVs as carriers, BDDSs offer these advantages by mimicking the structure of natural nanocarriers through bioengineering technologies. Furthermore, BDDSs demonstrate fewer limitations and irregularities than natural materials and can overcome several shortcomings associated with natural carriers. Although research remains ongoing to resolve these limitations, it is anticipated that BDDSs possess the potential to overcome challenges associated with traditional DDS, with a promising future in the treatment of human diseases.

Electrodeposition-Assisted Rapid Preparation of Pt Nanocluster/3D Graphene Hybrid Nanozymes with Outstanding Multiple Oxidase-Like Activity for Distinguishing Colorimetric Determination of Dihydroxybenzene Isomers

Here, we demonstrate a facile bottom-up strategy to fabricate Pt nanoclusters (Pt NCs) grafted onto three-dimensional graphene foam (3D GF) assisted by cetyltrimethyl ammonium bromide (CTAB) using the electrodeposition method. The homogeneous grafting of Pt NC onto 3D GF is due to the formation of hemimicelles above some CTAB concentration. With the unique nanocluster structure and the high content of Pt⁰, the Pt NC/3D GF nanohybrid exhibits extremely high activity and shows higher reusability and stability. Apart from the intrinsic oxidase-like activity with 3,3',5,5'-tetramethylbenzidine (TMB) as the substrate, the Pt NC/3D GF nanohybrid can act simultaneously as an effective polyphenol oxidase (PPO) mimic, such as tyrosinase, catechol oxidase, and laccase. More importantly, utilizing intrinsic catechol oxidase-like activity and the oxidase-like activity with TMB as the substrate of the nanohybrid, distinguishing colorimetric determination of dihydroxybenzene isomers (catechol and hydroquinone) is performed. Distinguishing colorimetric analysis of dihydroxybenzene isomers was first developed using nanozymes. The present work provides a simple bottom-up approach for the reasonable fabrication of various nanostructured nanozymes with excellent performance using the electrodeposition method assisted with surfactants.

Enteromorpha prolifera-derived Fe3C/C composite as advanced catalyst for hydroxyl radical generation and efficient removal for organic dye and antibiotic

Enteromorpha prolifera-derived Fe₃C/C composite has been fabricated through a facile one-step calcination method. As an advanced Fenton-like catalyst, the obtained Fe₃C/C composite displayed high catalytic reactivity to generate hydroxyl radicals. It is worth to note that the removal rate of methylene blue (MB) could effectively reach 100% in a wide pH range (pH = 2˜12) and the maximum degradation capacity of the composite is 660 mg/g. The stability and reusability of Fe₃C/C composite catalyst have also been tested, which could remain the removal rate at 100% after 6 consecutive runs. To illustrate the practical application possibility, the Fe₃C/C composite catalyst was used for degradation of papermaking and dyeing waste water, which could reduce the COD (chemical oxygen demand) value to less than 50. Additionally, the antibiotic norfloxacin (NOR) could also be catalytically removed by the Fe₃C/C composite and the possible removal pathway has also been proposed. The excellent removal performance of Fe₃C/C composite for MB and NOR may be attributed to the synergistic effect between porous carbon adsorption and Fe₃C catalysis. This study not only provides novel insights into recycling of waste biomass, but also paves a new way for the application of Fe₃C/C in dyes and antibiotics waste water treatment areas.

Identification and comparative proteomic study of quail and duck egg white protein using 2-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry analysis

A proteomic study of egg white proteins from 2 major poultry species, namely quail (Coturnix coturnix) and duck (Anas platyrhynchos), was performed with comparison to those of chicken (Gallus gallus) through 2-dimensional polyacrylamide gel electrophoresis (2-DE) analysis. By using matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF MS/MS), 29 protein spots representing 10 different kinds of proteins as well as 17 protein spots designating 9 proteins were successfully identified in quail and duck egg white, respectively. This report suggested a closer relationship between quail and chicken egg white proteome patterns, whereas the duck egg white protein distribution on the 2-DE map was more distinct. In duck egg white, some well-known major proteins, such as ovomucoid, clusterin, extracellular fatty acid-binding protein precursor (ex-FABP), and prostaglandin D2 synthase (PG D2 synthase), were not detected, while two major protein spots identified as “deleted in malignant brain tumors 1” protein (DMBT1) and vitellogenin-2 were found specific to duck in the corresponding range on the 2-DE gel map. These interspecies diversities may be associated with the egg white protein functions in cell defense or regulating/supporting the embryonic development to adapt to the inhabiting environment or reproduction demand during long-term evolution. The findings of this work will give insight into the advantages involved in the application on egg white proteins from various egg sources, which may present novel beneficial properties in the food industry or related to human health.

Muscovy duck reovirus p10.8 protein localizes to the nucleus via a nonconventional nuclear localization signal

Background

It was previously report that the first open reading frame of Muscovy duck reocvirus S4 gene encodes a 95-amino-acid protein, designed p10.8, which has no sequence similarity to other known proteins. Its amino acid sequence offers no clues about its function.

Results

Subcellular localization and nuclear import signal of p10.8 were characterized. We found that p10.8 protein localizes to the nucleus of infected and transfected cells, suggesting that p10.8 nuclear localization is not facilitated by viral infection or any other viral protein. A functional non-canonical nuclear localization signal (NLS) for p10.8 was identified and mapped to N-terminus residues 1–40. The NLS has the ability to retarget a large cytoplasmic protein to the nucleus.

Conclusions

p10.8 imported into the nucleus might via a nonconventional signal nuclear signal.

Determination of Guan-Fu Base A, a new anti-arrhythmic, in human plasma by gas chromatography and electron-capture detection

A gas chromatographic-electron capture detection (GC-ECD) method has been developed for determining Guan-Fu Base A (GFA), an experimental anti-arrhythmic, in human plasma. The method was based on one-step liquid-liquid extraction with toluene and chemical derivatization with pentafluoropropionic anhydride followed by GC-ECD. The derivatives of GFA and metoprolol (Met, internal standard) were confirmed by gas chromatography-mass spectrometry (GC-MS) to be dipentafluoropropionyl-GFA and dipentafluoropropionyl-Met. The method was linear over the concentration ranges of 0.1-20.0 and 1.0-30.0 microg/ml with the detection limit of 0.05 microg/ml at S/N=5. The intra- and inter-assay precisions were less than 6 and 10%, and accuracy 99.70+/-3.30 and 97.60+/-5.99%, respectively. The absolute recoveries were 81.88, 77.35, 80.79 and 83.85% for GFA at concentrations of 0.5, 1.0, 5.0 and 14.0 microg/ml and 88.24% for Met at 3.0 microg/ml, respectively.

Restriction site-free insertion of PCR products directionally into vectors

A restriction site-free cloning method has been developed for inserting a PCR product into a vector flexibly and precisely at any desired location with high efficiency. The method uses a pair of DNA integration primers with two portions. The 3' portion isolates the inserts by PCR, and the 5' portion integrates the PCR products into the homologous region of the vector. For mutagenesis, a third portion of mutation-generating sequences can be placed in between the 3' and 5' portions. This method has been used to clone the E. coli gene that codes for peptidyl-tRNA hydrolase, expressing it as a native protein and as a glutathione S-transferase fusion protein. It was also applied to convert a construct of the E. coli fatty acid biosynthesis protein with an N-terminal hexa-histidine tag into a construct with a C-terminal hexa-histidine tag.