Some properties of gustation in the larva of Pieris brassicae

The effects of some chemical substances on feeding response were studied in the larvae of Pieris brassicae L. Some synergistic effects between feeding stimulants were found. The larvae appeared to be highly sensitive to deterrents. In the medial sensillum styloconicum of the maxillae a chemoreceptor is present which is stimulated by a wide range of specific feeding inhibitors among which many belong to the alkaloids. Some physiological properties of the deterrent sensitive receptor are given and its significance in food selection behaviour is discussed.

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Résumé Les effets de quelques substances chimiques sur la prise de nourriture ont été étudiés chez la chenille de Pieris brassicae. Des effets synergiques se manifestent entre certains acides aminés ou certaines vitamines et le saccharose, lorsque ces produits sont à des concentrations appropriées. Par ailleurs les chenilles se montrent très sensibles à la présence de substances inhibant la prise de nourriture. Un neurone chimiorécepteur appartenant au sensillum styloconicum médian des maxilles se révèle sensible à une grande variété de ces substances inhibitrices, dont la plupart appartiennent aux alcaloides stéroides. Ce récepteur est sensible aux composés voisins de l'ecdysone présents dans certaines plantes, et son rôle physiologique est discuté, en rapport avec le comportement alimentaire et le choix de la nourriture.

     

Determine the quality of human embryonic stem colonies with laser light scattering patterns

Background

With the prompt developments of regenerative medicine, the potential clinical applications of human embryonic stem cells have attracted intense attention. However, the labor-intensive and complex manual cell selection processes required during embryonic stem cell culturing have seriously limited large-scale production and broad applications. Thus, availability of a label-free, non-invasive platform to replace the current cumbersome manual selection has become a critical need.

Results

A non-invasive, label-free, and time-efficient optical platform for determining the quality of human embryonic stem cell colonies was developed by analyzing the scattering signals from those stem cell colonies. Additionally, confocal microscopy revealed that the cell colony morphology and surface structures were correlated with the resulting characteristic light scattering patterns. Standard immunostaining assay (Oct-4) was also utilized to validate the quality-determination from this light scattering protocol. The platform developed here can therefore provide identification accuracy of up to 87% for colony determination.

Conclusions

Our study here demonstrated that light scattering patterns can serve as a feasible alternative approach to replace conventional manual selection for human embryonic stem cell cultures.     

Rab4：细胞囊泡循环运输过程的重要因子

囊泡运输是真核细胞中物质运输及信息交流的重要形式,Rab蛋白在这个过程中发挥着重要功能.Rab4是Rab蛋白家族的成员之一,参与调控早期内体的分选与内体循环途径.Rab4包括Rab4A、Rab4B和Rab4C 3个亚型.本文主要阐述了Rab4的结构特征、主要的效应蛋白和参与运输的货物蛋白以及影响细胞自噬、葡萄糖摄取、神经调节、心脏功能及肿瘤发生方面的功能.     

SUMO-targeted ubiquitin ligase (STUbL) Slx5 regulates proteolysis of centromeric histone H3 variant Cse4 and prevents its mislocalization to euchromatin

Centromeric histone H3, CENP-A^Cse4, is essential for faithful chromosome segregation. Stringent regulation of cellular levels of CENP-A^Cse4 restricts its localization to centromeres. Mislocalization of CENP-A^Cse4 is associated with aneuploidy in yeast and flies and tumorigenesis in human cells; thus defining pathways that regulate CENP-A levels is critical for understanding how mislocalization of CENP-A contributes to aneuploidy in human cancers. Previous work in budding yeast shows that ubiquitination of overexpressed Cse4 by Psh1, an E3 ligase, partially contributes to proteolysis of Cse4. Here we provide the first evidence that Cse4 is sumoylated by E3 ligases Siz1 and Siz2 in vivo and in vitro. Ubiquitination of Cse4 by the small ubiquitin-related modifier (SUMO)-targeted ubiquitin ligase (STUbL) Slx5 plays a critical role in proteolysis of Cse4 and prevents mislocalization of Cse4 to euchromatin under normal physiological conditions. Accumulation of sumoylated Cse4 species and increased stability of Cse4 in slx5∆ strains suggest that sumoylation precedes ubiquitin-mediated proteolysis of Cse4. Slx5-mediated Cse4 proteolysis is independent of Psh1, since slx5∆ psh1∆ strains exhibit higher levels of Cse4 stability and mislocalization than either slx5∆ or psh1∆ strains. Our results demonstrate a role for Slx5 in ubiquitin-mediated proteolysis of Cse4 to prevent its mislocalization and maintain genome stability.     

Osmotic stress blocks NF-kappaB-dependent inflammatory responses by inhibiting ubiquitination of IkappaB

The inhibitory effects of hypertonic conditions on immune responses have been described in clinical studies; however, the molecular mechanism underlying this phenomenon has yet to be defined. Here we investigate osmotic stress-mediated modification of the NF-kappaB pathway, a central signaling pathway in inflammation. We unexpectedly found that osmotic stress could activate IkappaBalpha kinase but did not activate NF-kappaB. Osmotic stress-induced phosphorylated IkappaBalpha was not ubiquitinated, and osmotic stress inhibited interleukin 1-induced ubiquitination of IkappaBalpha and ultimately blocked expression of cytokine/chemokines. Thus, blockage of IkappaBalpha ubiquitination is likely to be a major mechanism for inhibition of inflammation by hypertonic conditions.     

Mechanistic aspects of CoII(HAPP)(TFA)2 in DNA bulge-specific recognition

A novel octahedral complex Co^II(HAPP)(TFA)₂ [hexaazaphenantholine-cyclophane (HAPP), trifluoroacetate (TFA)] is a DNA bulge-specific probe with single-strand DNA cleavage activity in the presence of H₂O₂. This complex exhibits low affinity towards double-stranded DNA and low reactivity toward single-stranded DNA. Metal–HAPP complexes with different coordination number and ring size were synthesized and their selectivity and reactivity for DNA bulges were compared. The DNA sequence at the bulge site influences the intensity of cleavage at the bulge and the flanking sites after piperidine treatment. Cleavage specificity of Co^II(HAPP)(TFA)₂ was characterized extensively using scavenger reagents to quench the cleavage reaction and high-resolution polyacrylamide gel electrophoresis. In addition, 3′-phosphoglycolate cleavage products were trapped and analyzed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. These data were used to deduce that the DNA cleavage pathway for Co^IIHAPP²⁺ in the presence of H₂O₂ involves 4′-H abstraction of the deoxyribose moiety.     

Addition of Lidocaine Injection Immediately before Physiotherapy for Frozen Shoulder: A Randomized Controlled Trial

The intraarticular injection of lidocaine immediately before a physiotherapy session may relieve pain during the stretching and mobilization of the affected joint in patients with a frozen shoulder, thus enhancing the treatment effect. To compare the effects of intraarticular injection of lidocaine plus physiotherapy to that of physiotherapy alone in the treatment of a frozen shoulder, a prospective randomized controlled trial was conducted in the rehabilitation department of a private teaching hospital. Patients with a frozen shoulder were randomized into the physiotherapy group or the lidocaine injection plus physiotherapy (INJPT) group. The subjects in the INJPT group underwent injection of 3 ml of 1% lidocaine into the affected shoulder 10 to 20 minutes before each physiotherapy session. In each group, the treatment lasted 3 months. The primary outcome measures were the active and passive range of motion of the affected shoulder. The secondary outcome measures were the results of the Shoulder Disability Questionnaire, the Shoulder Pain and Disability Index, and the 36-item Short-Form Health Survey (SF-36). The outcome measures were evaluated before treatment and 1, 2, 3, 4, and 6 months after the start of treatment. The group comparisons showed significantly greater improvement in the INJPT group, mainly in active and passive shoulder range of motion in flexion and external rotation and improvements in pain and disability (P < 0.05); however, no significant group difference was seen in the SF-36 results. The intraarticular injection of lidocaine immediately before a physiotherapy session might be superior to physiotherapy alone in the treatment of a frozen shoulder.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01817348","term_id":"NCT01817348"}}NCT01817348     

环指蛋白RING1与A型核纤层蛋白的细胞内相互作用

环指蛋白RING1能结合DNA并抑制基因的转录.采用酵母双杂交方法从人骨骼肌文库中筛选出了与A型核纤层蛋白(lamin A)结合的RING1蛋白,回复杂交酵母能在缺陷培养基上生长.RING1与绿色荧光蛋白融合载体转染HEK293细胞,激光共聚焦显微观察发现RING1能与带红色荧光蛋白的lamin A蛋白在细胞核周围共定位.免疫共沉淀结果证明RING1与lamin A能够相互作用.结果证明了一个新的lamin A结合蛋白,为揭示lamin A影响基因表达乃至细胞衰老提供了依据.     

Effects of engineered nanoparticles on the assembly of exopolymeric substances from phytoplankton

The unique properties of engineered nanoparticles (ENs) that make their industrial applications so attractive simultaneously raise questions regarding their environmental safety. ENs exhibit behaviors different from bulk materials with identical chemical compositions. Though the nanotoxicity of ENs has been studied intensively, their unintended environmental impacts remain largely unknown. Herein we report experimental results of EN interactions with exopolymeric substances (EPS) from three marine phytoplankton species: Amphora sp., Ankistrodesmus angustus and Phaeodactylum tricornutum. EPS are polysaccharide-rich anionic colloid polymers released by various microorganisms that can assemble into microgels, possibly by means of hydrophobic and ionic mechanisms. Polystyrene nanoparticles (23 nm) were used in our study as model ENs. The effects of ENs on EPS assembly were monitored with dynamic laser scattering (DLS). We found that ENs can induce significant acceleration in Amphora sp. EPS assembly; after 72 hours EN-EPS aggregation reached equilibrium, forming microscopic gels of ～4-6 μm in size. In contrast, ENs only cause moderate assembly kinetic acceleration for A. angustus and P. tricornutum EPS samples. Our results indicate that the effects of ENs on EPS assembly kinetics mainly depend on the hydrophobic interactions of ENs with EPS polymers. The cycling mechanism of EPS is complex. Nonetheless, the change of EPS assembly kinetics induced by ENs can be considered as one potential disturbance to the marine carbon cycle.