Interplant communication: airborne methyl jasmonate is essentially converted into JA and JA-Ile activating jasmonate signaling pathway and VOCs emission

Methyl jasmonate (MeJA) was identified as an airborne signal involved in mediating interplant defense response communications over a decade ago. However, how MeJA activates plant defense systems and what becomes of the compound after it has done so has, thus far, remained unknown. To investigate this, Achyranthes bidentata plants were exposed to deuterated methyl jasmonate (d₂MeJA) followed by absolute quantification of metabolic products of d₂MeJA, and emissions of volatile organic compound (VOC) as defensive markers. We found that d₂MeJA was metabolized mainly into deuterated jasmonic acid (d₂JA) and jasmonoyl isoleucine (d₂JA-Ile), and to a much lesser extent, deuterated jasmonoyl leucine (d₂JA-Leu). Increases in d₂JA-Ile/Leu and also endogenous JA-Ile/Leu were tightly co-related with, and significantly influenced the pattern and amount of, VOC emissions. The amount of accumulated d₂JA-IIe was 13.1-fold higher than d₂JA-Leu, whereas the amounts of JA-IIe and JA-Leu accumulated were almost identical. This study demonstrates that exogenous MeJA activates defensive systems (such as VOC emissions) in receiver plants by essentially converting itself into JA and JA-IIe and initiating a signal transduction leading to VOC emissions and induction of endogenous JA-IIe and JA-Leu, which in turn cause further amplification of VOC emissions.     

Outer arm fucosylation of N-glycans increases in sera of hepatocellular carcinoma patients

Serum glycans are promising markers for early-stage cancer detection, but the research remains challenging because low concentrations of serum glycoproteins are secreted from early-stage tumors. We have established an N-glycan profiling method using liquid chromatography electrospray ionization-mass spectrometry with high sensitive derivative, trimethyl(4-aminophenyl)ammonium chloride (TMAPA). The mass sensitivity of TMAPA-labeled oligosaccharides was enhanced more than 50 times compared with 2-aminopyridine (PA) labeled oligosaccharides, and the analytical period was significantly shortened compared with traditional HPLC 2D-mapping. Using this method, we found about 28 major N-linked oligosaccharides in human sera, and we investigated their alterations in patients who developed hepatocellular carcinoma (HCC). We found that outer arm fucosylation (attached GlcNAc via an alpha 1-3/4 linkage) in highly branched oligosaccharides increased significantly in sera of HCC patients. Normalizing the level of outer arm fucosylation by taking into account platelet concentration allowed us to distinguish more clearly between HCC and LC patients.     

聚氨酯／液晶（PU／EBBA）复合膜的血液相容性研究

以聚氨酯弹性体为基质材料,与液晶化合物EBBA共混后,由溶剂蒸发法浇铸成膜。偏光显微镜观察证实了复合膜中液晶相的存在。用动态凝血实验、血小板粘附实验和扫描电镜观察的方法研究了复合膜中液晶含量对材料抗凝血性能的影响。结果表明,只有当液晶含量达到30%（wt）时,复合膜的血液相容性随着液晶含量的增加有明显改善,同时发现复合膜表面吸附的血小板随着液晶含量的增加而明显减少。     

Improved solubility of β-cyclodextrin inclusion complexes by using liquid ammonia as a solvent and the possibility of asymmetric reduction

Dramatic improvement in the poor solubility of β-cyclodextrin (β-CD) and its inclusion complexes in water was achieved by using liquid ammonia (liq. NH₃) instead of water as the solvent. Asymmetric NaBH₄ reduction of the carbonyl groups of the inclusion complexes in liq. NH₃ was examined in a homogeneous condition to give the corresponding alcohols with moderate chirality.     

重组乙肝疫苗纯度高效液相层析(HPLC)测定方法的改进

为建立重组汉逊酵母乙肝疫苗HPLC检定方法,应用TSK－G5000PW检测系统测定汉逊酵母重组乙肝疫苗表面抗原的纯度,对不同样品处理液的配比浓度和处理时间分别进行了探讨,作者选用DTT／Tween-80作为样品处理效果优于DTT＋Tween-20,1:50Tween-80与0.1mol/L等量混合为样品处理液的适宜浓度。样品处理液与等量样品混匀时间介于35s-2min时,HPLC分离效果好,结果稳定。该处理液及处理时间对CHO细胞及Merck酿酒酵母重组乙肝疫苗表面抗原的HPLC纯度测定无影响。结果表明：现有的HPLC检测系统用0.1mol/L DTT与1：50 Tween-80等量混合处理后能有效地检测不同类型重组乙肝疫苗表面抗原的纯度。     

Structural and developmental studies of Chlamydomyzium oviparasiticum from Rhabditis nematodes and in culture

The oomycete (Peronosporomycete) Chlamydomyzium oviparasiticum, previously recorded as a parasite of rotifer eggs, was found infecting Rhabditis nematodes in a sample of rotting garden compost. For the first time C. oviparasiticum was cultured in liquid media, which enabled more detailed studies of zoospore behaviour and facilitated the use of confocal microscopy. Rhabditis nematodes were successfully re-infected from liquid-cultured inoculum. Light (including video) microscopy and transmission electron microscopy were used to document details of thallus development, zoospore release and resting spore morphology to enable comparison with other oomycete species. This species showed several significant saprolegnialian characters such as the ‘achlyoid’ pattern of spore formation, centrifugal cleavage and structured encystment vesicles. In contrast, spore release into a transient vesicle was a peronosporalean characteristic. The thick-walled resting spores showed relatively poor cytoplasmic preservation and had a thick multi-layered wall. It was still not possible to unequivocably decide whether these were chlamydospores or parthenogenically formed oospores. The phylogenetic significance of these observations is discussed.     

Enhancing native chemical ligation for challenging chemical protein syntheses

Native chemical ligation has enabled the chemical synthesis of proteins for a wide variety of applications (e.g., mirror-image proteins). However, inefficiencies of this chemoselective ligation in the context of large or otherwise challenging protein targets can limit the practical scope of chemical protein synthesis. In this review, we focus on recent developments aimed at enhancing and expanding native chemical ligation for challenging protein syntheses. Chemical auxiliaries, use of selenium chemistry, and templating all enable ligations at otherwise suboptimal junctions. The continuing development of these tools is making the chemical synthesis of large proteins increasingly accessible.     

Structural and dynamic properties of liquid alkali metals: molecular dynamics

Molecular dynamics simulations in the canonical ensemble have been performed to calculate structural and transport properties of liquid alkali metals. The alkali metals considered in this work were Na, K, Rb and Cs. Two Yukawa-type potentials were employed as the interaction law among particles. This function is written in terms of two adjustment parameters which make possible tuning the softness of the potential core and the range of the attractive part. The radial distribution functions and transport properties such as self-diffusion and shear viscosity, were calculated in a thermodynamic state near the melting point. The radial distribution function calculated for each alkali metal was compared with previous simulation results where a more elaborated potential was employed. From this comparison we found an excellent agreement. Our results for transport properties were also compared with the available experimental data and a good agreement was found.     

Regulation of synaptic nanodomain by liquid–liquid phase separation: A novel mechanism of synaptic plasticity

Advances in microscopy techniques have revealed the details of synaptic nanodomains as defined by the segregation of specific molecules on or beneath both presynaptic and postsynaptic membranes. However, it is yet to be clarified how such segregation is accomplished without demarcating membrane and how nanodomains respond to the neuronal activity. It was recently discovered that proteins at the synapse undergo liquid–liquid phase separation (LLPS), which not only contributes to the accumulation of synaptic proteins but also to further segregating the proteins into subdomains by forming phase-in-phase structures. More specifically, CaMKII, a postsynaptic multifunctional kinase that serves as a signaling molecule, acts as a synaptic cross-linker which segregates certain molecules through LLPS in a manner triggered by Ca²⁺. Nanodomain formation contributes to the establishment of trans-synaptic nanocolumns, which may be involved in the optimization of spatial arrangement of the transmitter release site and receptor, thereby serving as a new mechanism of synaptic plasticity.     

Novel biomarkers in amniotic fluid for early assessment of intraamniotic infection

Intra-amniotic infection/inflammation (IAI) is associated with preterm birth, short and long-term adverse clinical outcomes and oxidative stress. The diagnosis of IAI is based on histological and clinical findings; however, often these results are unspecific. Therefore, efforts have been directed towards validating reliable methods for patients lacking overt clinical symptoms. In this study, amniotic fluid (AF) samples were prospectively collected from 23 women grouped into two categories (with or without IAI) following clinical, microbiological and histological criteria. AFs were analyzed using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) for the determination of the following biomarkers: oxidized and nitrated tyrosines (Tyr), 8-hydroxy-2'-deoxyguanosine (8OHdG), oxidized glutathione (GSSG) and glutathione sulfonamide (GSA). 3-NO₂-Tyrosine (3NO₂-Tyr) and GSSG concentrations in AF were not identified as significantly relevant biomarkers in the presence of IAI. However, inflammatory biomarkers such as GSA (p=0.002) and 3-Chloro-Tyrosine [3Cl-Tyr (p=0.049)], and oxidative stress biomarker 8OHdG (p=0.021) were significantly increased in AF with IAI as compared to normal controls. Biomarkers of inflammation and oxidative stress determined in AF samples could represent a new approach towards an early diagnosis of IAI and subsequent chorioamnionitis in the clinical setting.