Pierce's Disease of Grapevines in Taiwan: Isolation,Cultivation and Pathogenicity of Xylella fastidiosa

Characteristic symptoms of Pierce's disease (PD) in grapevines (Vitis vinifera L.) were observed in 2002 in the major grape production fields of central Taiwan. Disease severity in vineyards varied, and all investigated grape cultivars were affected. Diseased tissues were collected from fields for subsequent isolation and characterization of the causal agent of the disease (Xylella fastidiosa). Koch's postulates were fulfilled by artificially inoculating two purified PD bacteria to grape cultivars Kyoho, Honey Red and Golden Muscat. The inoculated plants developed typical leaf‐scorching symptoms, and similar disease severity developed in the three cultivars from which the bacterium was readily re‐isolated, proving that the leaf scorch of grapevines in Taiwan is caused by the fastidious X. fastidiosa. This confirmed PD of grapevines is also the first report from the Asian Continent. Phylogenetic analyses were performed by comparing the 16S rRNA gene and 16S‐23S rRNA internal transcribed spacer region (16S‐23S ITS) of 12 PD strains from Taiwan with the sequences of 13 X. fastidiosa strains from different hosts and different geographical areas. Results showed that the PD strains of Taiwan were closely related to the American X. fastidiosa grape strains but not to the pear strains of Taiwan, suggesting that the X. fastidiosa grape and pear strains of Taiwan may have evolved independently from each other.     

Hagfish phylogeny and taxonomy,with description of the new genus Rubicundus (Craniata,Myxinidae)

A recent phylogenetic analysis of the Myxinidae based on the 16S rRNA gene resulted in synonymization of Paramyxine with Eptatretus. This created homonymy of Paramyxine fernholmi with Eptatretus fernholmi and Paramyxine wisneri with Eptatretus wisneri. In order to resolve this nomenclatural dilemma, we made a more extensive phylogenetic assessment of the Myxinidae and examined the nomenclature of the family. We used 75 sequences (37 of which new for this study) of a 561 bp fragment of the 16S rRNA gene, representing 33 species, and 72 sequences (37 of which new for this study) of a 687 bp fragment of the cytochrome c oxidase subunit I (COI) gene, representing 23 species, to reconstruct the phylogeny of Myxinidae. The monophyly of the subfamily Myxininae, traditionally characterized by having a single pair of external gill openings, was rejected (0.50 Bayesian posterior probability) by the 16S analysis, but supported by the COI and combined COI+16S analyses (0.99 and 0.81 Bpp, respectively). The monophyly of the subfamily Eptatretinae, characterized by having several pairs of external gill openings, was not supported by the 16S analysis and rejected by the COI and combined COI+16S analysis due to the placement of Eptatretus lopheliae as the earliest branch of Myxinidae (0.71 and 0.57 Bpp, respectively). Eptatretus lopheliae and Eptatretus rubicundus formed a monophyletic group and were allocated to a new genus, Rubicundus, characterized by the presence of an elongated tubular nostril and reddish coloration. A new monotypic subfamily, Rubicundinae, was proposed for Rubicundus. The synonymy of the genera Paramyxine and Quadratus with Eptatretus was confirmed. E. fernholmi is renamed Eptatretus luzonicus. Eptatretus wisneri was renamed Eptatretus bobwisneri. Petromyzon cirrhatus Forster, 1801, Homea banksii Fleming, 1822, and Bdellostoma forsteri Müller, 1836 are synonyms, but no type specimens are known to exist. Petromyzon cirrhatus was designated as type species of Eptatretus, conserving present usage. Gastrobranchus dombeyi Shaw, 1804 has priority over other names for Chilean myxinids. Bdellostoma stoutii was designated as type species of Polistotrema Gill. The validity of the Western Atlantic Myxine limosa as distinct from the Eastern Atlantic Myxine glutinosa was confirmed.     

Curcumin analog HO‐3867 triggers apoptotic pathways through activating JNK1/2 signalling in human oral squamous cell carcinoma cells

Human oral squamous cell carcinoma (OSCC) is the common head and neck malignancy in the world. While surgery, radiotherapy and chemotherapy are emerging as the standard treatment for OSCC patients, the outcome is limited to the recurrence and side effects. Therefore, patients with OSCC require alternative strategies for treatment. In this study, we aimed to explore the therapeutic effect and the mode of action of the novel curcumin analog, HO‐3867, against human OSCC cells. We analysed the cytotoxicity of HO‐3867 using MTT assay. In vitro mechanic studies were performed to determine whether MAPK pathway is involved in HO‐3867 induced cell apoptosis. As the results, we found HO‐3867 suppressed OSCC cells growth effectively. The flow cytometry data indicate that HO‐3867 induce the sub‐G1 phase. Moreover, we found that HO‐3867 induced cell apoptosis by triggering formation of activated caspase 3, caspase 8, caspase 9 and PARP. After dissecting MAPK pathway, we found HO‐3867 induced cell apoptosis via the c‐Jun N‐terminal kinase (JNK)1/2 pathway. Our results suggest that HO‐3867 is an effective anticancer agent as its induction of cell apoptosis through JNK1/2 pathway in human oral cancer cells.     

Continuous infusion of cholecystokinin and meal pattern in the rat

Purified natural cholecystokinin (CCK-33) was infused continuously for two days at a rate of 5.9 μg/hr in two rats trained to bar-press for food (Noyes pellet 45 mg) on a fixed ratio of five bar presses to obtain one pellet. The animals also received control surgery and were tested in the operant chamber for two days, one prior to and the other following the CCK-33 treatment. CCK-33 suppressed the number of meals, the total amount of food eaten, and the total duration of time spent eating. However, the size of each meal and the rate of intake were not affected. The CCK effect did not interact with the light-dark phases of diurnal cycle. It appears that a major effect of continuous systemic elevation of CCK-33 is to reduce food intake by prolonging the satiety period rather than by decreasing the individual meal size.     

Arginine vasopressin produces inhibition upon respiration without pressor effect in the rat

The purpose of the current study was to examine where arginine vasopressin (AVP) inhibits respiration by direct action on the areas of the ventrolateral medulla (VLM) in the rat. The animal was anesthetized by urethane (1.2 g/kg, i.p.), paralyzed with gallamine triethiodide, and artificially ventilated. Catheterization of the femoral artery and vein, and bilateral vagotomy were performed. The rat was then placed upon a stereotaxic instrument in a prone position. The phrenic nerve was separated and cut peripherally. Phrenic nerve activity (PNA) was monitored at normocapnia and hypercapnia in hyperoxia. Microinjection of AVP into various subregions of the VLM was then performed. In response to AVP microinjection, a transient period of apnea and then a significant decrease in PNA amplitude were observed. Arterial blood pressure was unchanged. This inhibition of PNA with AVP treatment was site-specific, attenuated by raising CO2 concentration, and totally abolished by pretreatment with AVP V1A receptor antagonist. Data of the present study indicate that endogenous resource of AVP may produce an inhibitory effect upon respiration via AVP receptors presented on neurons within the VLM.     

Efficient synthesis of 'redox-switched' naphthoquinone thiol-crown ethers and their biological activity evaluation

Series of naphthoquinone thiol-crown ethers had been prepared. The antibacterial, antifungal, and cytotoxic activities of these synthetic naphthoquinone thiol-crown ethers were investigated. All of the compounds tested displayed antibacterial, cytotoxic and antifungal activities. The bis-naphthoquinone thiol-crown ether 7a was the most potent inhibitor among tested analogues against Staphylococcus aureus methicillin resistance with MIC value of 2.68 microM.     

人造血干/祖细胞多态性的研究:Ⅺ.人正常骨髓CD34~ 造血细胞周期动力学相关大分子DNA、RNA和PRO含量的分析

DNA、RNA和PRO的合成、积累及相互关系是调控细胞周期动力学最主要的三个参数。同时检测这些组成部分能够更精确细致地评判细胞的周期动力学特征。本文探索了人正常骨髓CD34~ 造血细胞周期动力学相关大分子DNA、RNA和PRO的含量,以便认识CD34~ 造血细胞周期动力学的特征。用新型CIMS-100免疫磁性分离系统高效富集人骨髓CD34~ 造血细胞,经FCM及APAAP鉴定,富集的CD34~ 造血细胞的纯度达90～95%。随之采用碘化丙啶(PI)、派若宁Y(PY)及异硫氰荧光素(FITC)分别进行标记DNA、RNA和PRO并在FCM上检测。结果表明,DNA、RNA和PRO在CD34~ 造血细胞中的含量明显低于单个核细胞,分别仅占后者的34±3%、48±21%及62±14%。结合我们以往的结果,我们认为CD34~ 造血细胞的确是一独特的体细胞群,不仅表现在重建造血与免疫学功能上,而且表现在细胞周期动力学上。据我们所知,这是目前国际上首次有关人CD34~ 造血细胞周期动力学相关大分子的系统分析报道,提供了大多数CD34~ 造血细胞处于静止期的直接证据。