Different strategies of energy storage in cultured and freshly isolated Symbiodinium sp.

The endosymbiotic relationship between cnidarians and Symbiodinium is critical for the survival of coral reefs. In this study, we developed a protocol to rapidly and freshly separate Symbiodinium from corals and sea anemones. Furthermore, we compared these freshly‐isolated Symbiodinium with cultured Symbiodinium to investigate host and Symbiodinium interaction. Clade B Symbiodinium had higher starch content and lower lipid content than those of clades C and D in both freshly isolated and cultured forms. Clade C had the highest lipid content, particularly when associated with corals. Moreover, the coral‐associated Symbiodinium had higher protein content than did cultured and sea anemone‐associated Symbiodinium. Regarding fatty acid composition, cultured Symbiodinium and clades B, C, and D shared similar patterns, whereas sea anemone‐associated Symbiodinium had a distinct pattern compared coral‐associated Symbiodinium. Specifically, the levels of monounsaturated fatty acids were lower than those of the saturated fatty acids, and the level of polyunsaturated fatty acids (PUFAs) were the highest in all examined Symbiodinium. Furthermore, PUFAs levels were higher in coral‐associated Symbiodinium than in cultured Symbiodinium. These results altogether indicated that different Symbiodinium clades used different energy storage strategies, which might be modified by hosts.     

Biosafety of non-surface modified carbon nanocapsules as a potential alternative to carbon nanotubes for drug delivery purposes

Background

Carbon nanotubes (CNTs) have found wide success in circuitry, photovoltaics, and other applications. In contrast, several hurdles exist in using CNTs towards applications in drug delivery. Raw, non-modified CNTs are widely known for their toxicity. As such, many have attempted to reduce CNT toxicity for intravenous drug delivery purposes by post-process surface modification. Alternatively, a novel sphere-like carbon nanocapsule (CNC) developed by the arc-discharge method holds similar electric and thermal conductivities, as well as high strength. This study investigated the systemic toxicity and biocompatibility of different non-surface modified carbon nanomaterials in mice, including multi-walled carbon nanotubes (MWCNTs), single-walled carbon nanotubes (SWCNTs), carbon nanocapsules (CNCs), and C₆₀ fullerene (C₆₀). The retention of the nanomaterials and systemic effects after intravenous injections were studied.

Methodology and Principal Findings

MWCNTs, SWCNTs, CNCs, and C₆₀ were injected intravenously into FVB mice and then sacrificed for tissue section examination. Inflammatory cytokine levels were evaluated with ELISA. Mice receiving injection of MWCNTs or SWCNTs at 50 µg/g b.w. died while C₆₀ injected group survived at a 50% rate. Surprisingly, mortality rate of mice injected with CNCs was only at 10%. Tissue sections revealed that most carbon nanomaterials retained in the lung. Furthermore, serum and lung-tissue cytokine levels did not reveal any inflammatory response compared to those in mice receiving normal saline injection.

Conclusion

Carbon nanocapsules are more biocompatible than other carbon nanomaterials and are more suitable for intravenous drug delivery. These results indicate potential biomedical use of non-surface modified carbon allotrope. Additionally, functionalization of the carbon nanocapsules could further enhance dispersion and biocompatibility for intravenous injection.     

Rapid optimization of electroporation conditions for plant cells,protoplasts, and pollen

The optimization of electroporation conditions for maximal uptake of DNA during direct gene transfer experiments is critical to achieve high levels of gene expression in transformed plant cells. Two stains, trypan blue and fluorescein diacetate, have been applied to optimize electroporation conditions for three plant cell types, using different square wave and exponential wave electroporation devices. The different cell types included protoplasts from tobacco, a stable mixotrophic suspension cell culture from soybean with intact cell walls, and germinating pollen from alfalfa and tobacco. Successful electroporation of each of these cell types was obtained, even in the presence of an intact cell wall when conditions were optimized for the electroporation pulse. The optimal field strength for each of these cells differs, protoplasts having the lowest optimal pulse field strength, followed by suspension cells and finally germinating pollen requiring the strongest electroporation pulse. A rapid procedure is described for optimizing electroporation parameters using different types of cells from different plant sources.     

中国林蛙与中华蟾蜍蝌蚪颅骨形态的系统进化比较

对无尾两栖动物系统进化的研究,主要是基于经典的形态学、现代分子生物学等技术。无尾两栖动物蝌蚪的进化与成体的进化可能是两个独立的过程,所以无尾两栖类蝌蚪形态及发育特征也可以作为研究系统进化的重要指征。本文对中国林蛙(Rana chensinensis)及中华蟾蜍(Bufo gargarizans)变态前蝌蚪的软骨性颅骨及鳃部骨骼进行形态学描述,基于幼体形态特征,进行系统建树。建树结果支持Orton将无尾两栖类蝌蚪划分为4种类型,认为最原始的类群为Ⅲ型蝌蚪,与Tihen的观点一致。新蛙亚目的中国林蛙和中华蟾蜍蝌蚪属Ⅳ型,是最进化的类群。     

Clinicopathologic analysis of fine needle aspiration cytology of the thyroid. A review of 1,613 cases and correlation with histopathologic diagnoses

OBJECTIVE: To evaluate the accuracy of fine needle aspiration (FNA) of thyroid lesions at our institution and to ascertain its usefulness in determining the therapeutic approach. STUDY DESIGN: The authors reviewed the results of 1,613 cases of FNA cytology of thyroid nodules performed from 1999 to 2001 at the Department of Pathology, Chonnam National University Hospital. Cytologic diagnoses were compared with histologic diagnoses in 207 cases that included both FNA and thyroid surgery. RESULTS: The sensitivity for the detection of neoplasms (carcinoma and follicular adenoma) was 78.4% and the specificity 98.2%. A false positive diagnosis was made in 1 case (1.8%) and false negative ones in 28 cases (21.5%). The diagnostic accuracy was 84.4%, with a positive predictive value of 99.0% and negative predictive value of 66.3%. The predictive value of a cytologic diagnosis was 100% in papillary carcinoma. CONCLUSION: FNA is a useful test in determining the therapeutic approach of thyroid lesions.     

中国林蛙蝌蚪的口器发育

采用扫描电镜和组织学技术观察了中国林蛙(Rana chensinensis)蝌蚪发育过程中口器外部形态结构的变化,以及中国林蛙蝌蚪口器内部结构特征.结果表明,在口器发育的初期,角质颌最先出现,接着出现唇乳突以及唇齿;在变态高峰期(G4l～G42),口器结构如唇齿、角质颌和唇乳突则是按以下顺序消失的,即唇齿最先消失,其次...     

A RING‐type E3 ligase controls anther dehiscence by activating the jasmonate biosynthetic pathway gene DEFECTIVE IN ANTHER DEHISCENCE1 in Arabidopsis

Suppression of expression of DAF [DEFECTIVE IN ANTHER DEHISCENCE1 (DAD1)‐Activating Factor], a gene that encodes a putative RING‐finger E3 ligase protein, causes non‐dehiscence of the anthers, alters pollen development and causes sterility in 35S:DAF RNAi/antisense Arabidopsis plants. This mutant phenotype correlates with the suppression of DAF but not with expression of the two most closely related genes, DAFL1/2. The expression of DAD1 was significantly reduced in 35S:DAF RNAi/antisense plants, and complementation with 35S:DAF did not rescue the dad1 mutant, indicating that DAF acts upstream of DAD1 in jasmonic acid biosynthesis. This assumption is supported by the finding that 35S:DAF RNAi/antisense plants showed a similar cellular basis for anther dehiscence to that found in dad1 mutants, and that external application of jasmonic acid rescued the anther non‐dehiscence and pollen defects in 35S:DAF antisense flowers. We further demonstrate that DAF is an E3 ubiquitin ligase and that its activity is abolished by C132S and H137Y mutations in its RING motif. Furthermore, ectopic expression of the dominant‐negative C132S or H137Y mutations causes similar indehiscence of anthers and reduction in DAD1 expression in transgenic Arabidopsis. This result not only confirms that DAF controls anther dehiscence by positively regulating the expression of DAD1 in the jasmonic acid biosynthesis pathway, but also supports the notion that DAF functions as an E3 ubiquitin ligase, and that the conserved RING‐finger region is required for its activity.     

中华蟾蜍蝌蚪颅骨发育的形态计量学分析

采用TPS(thin-plate spline)形态计量软件计量了中华蟾蜍Bufogargarizans幼体蝌蚪发育中软骨性颅骨的11项形态指标的变化,采用颅骨总长(TLC,the total length of chondrocranium)线性回归分析了各形态特征与颅骨总长的关系。通过对中华蟾蜍幼体蝌蚪颅骨的线性形态测量,结果表明喙上软骨、内睑部关节距等呈负异速生长,外睑部关节距呈同速生长;听囊等感受结构呈正异速生长,与Emerson等人的观点有所不同。基于中华蟾蜍幼体蝌蚪各期样本之间颅骨的发育存在着较大的差异,在实验样本的选取中既要考虑Gosner的分期,还要考虑同期蝌蚪个体体型大小。