First Report of Stem Blight of Eleocharis dulcis Caused by Phoma bellidis in China

Eleocharis dulcis is a perennial herbaceous plant in the family Cyperaceae, which is native to China and India where it grows well in moist-to-wet soils. It is commonly used as a fruit or a vegetable. From August 2009 to December 2010, symptoms were observed on E. dulcis stems in Tuanfeng County, Hubei, China, with the crop area affected estimated to be more than 1,300 ha per year. Corm yield was reduced by 20% on average with as much as 60% yield losses in some fields. Lesions were initially small, red-brown, and oval or circular that enlarged to produce apical necrosis and extending until the stems withered, usually within 2 months. To obtain isolates, diseased tissue was disinfested for 1 min in 0.1% mercuric chloride solution, rinsed with sterilized water, and plated on potato dextrose agar. Isolates with similar morphological characteristics were consistently recovered. Three isolates, CTF-3, CTF-10, and CTF-11, were used to further evaluate characteristics of the pathogen. After 7 days, white colonies were 76 to 80 mm across on oatmeal agar (OA) with sparse aerial hyphae and a slight salmon color in the conidial masses. Pycnidia produced on OA were globose to subglobose, usually with one slightly ostiolar papilla, olivaceous to olivaceous black, and 93 to 245 μm in diameter. Conidia were hyaline, unicellular, ellipsoidal, mostly with two polar guttules, and 3.6 to 6.2 × 2.0 to 3.3 μm. Chlamydospores were absent. Growth of the isolates on malt extract agar (MEA) was slower than on OA, and the colony diameters at 7 days were 60 to 65 mm. The reactions with 1M NaOH were both positive on OA and MEA where the cultures initially changed to yellow green and gradually turned to red. The pathogen was identified as Phoma bellidis Neerg. based on descriptions in Boerema et al. (2). Pathogenicity tests were performed with the three isolates in the laboratory by spraying conidial suspensions (1 × 10⁶ conidia/ml) containing 0.1% Tween 20 until runoff (30 ml per plant) onto stem surfaces of 50-day-old, 60 cm tall plants. For each isolate, there were 50 stems from five replicate plants that had multiple stems per plant. Control plants were treated with sterilized water containing 0.1% Tween 20 only. Plants were incubated with a 16-h photoperiod at 28°C and 90% relative humidity in an artificial climate chamber. Five days after inoculation, typical red-brown spots were observed on all inoculated stems but no symptoms were seen on water-treated control plants. Koch's postulates were fulfilled by reisolation of P. bellidis from diseased stems. The pathogenicity tests were repeated twice more with the same results. P. bellidis has only been reported previously on Bellis spp. from England, Denmark, Italy, the Netherlands, and Switzerland (1,2). Furthermore, there are only a few fungal diseases known to be associated with E. dulcis, and none so far that involve species of Phoma (3,4). To our knowledge, this is the first report of P. bellidis infecting E. dulcis worldwide. References: (1) M. M. Aveskamp et al. Stud. Mycol. 65:27, 2010. (2) G. H. Boerema et al. Phoma Identification Manual: Differentiation of Specific and Infra-Specific Taxa in Culture. CABI Publishing, Wallingford, UK, 2004. (3) P. L. Lentz. Am. Midl. Nat. 67:184, 1962. (4) L. Pan et al. J. Changjiang Vegetables (in Chinese) 14:10, 2010.

Permanent Genetic Resources added to the Molecular Ecology Resources Database 1 February 2010-31 March 2010

This article documents the addition of 228 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Anser cygnoides, Apodemus flavicollis, Athene noctua, Cercis canadensis, Glis glis, Gubernatrix cristata, Haliotis tuberculata, Helianthus maximiliani, Laricobius nigrinus, Laricobius rubidus, Neoheligmonella granjoni, Nephrops norvegicus, Oenanthe javanica, Paramuricea clavata, Pyrrhura orcesi and Samanea saman. These loci were cross-tested on the following species: Apodemus sylvaticus, Laricobius laticollis and Laricobius osakensis (a proposed new species currently being described).

Energetics of Stone-Wales defects in 4 A carbon nanotubes

Density functional calculations have been performed to study the formation of Stone-Wales defects in 4 A single-wall carbon nanotubes, which were firstly synthesized inside the AFI zeolite template. The minimum energy paths from perfect tubes to defect-containing ones are calculated by the nudged elastic band method. It is found that the C--C bonds "along" the tube axis are more likely to be rotated than those bonds "around" the circumference. There is a marked chirality dependence of the formation barriers, which are found to be lower than that of graphite. Our results may raise a question on the origin of superconductivity observed in these 4 A tubes.

Electronic and electrochemical properties of Li-doped carbon nanotube-zeolite complex

The electronic and electrochemical properties of Li-doped carbon nanotube-zeolite complex are studied by first-principles calculations. There are four possible sites for Li to be doped and the reactions are all exothermic. The corresponding energy band structures follow a rigid band picture and there are charge transfers from Li to the nanotube and/or zeolite. The Li capacity of the complex can be reached to 386 mAh g(-1) with only a slight increase in the cell volume, and the complex may be of good cyclic stability during the charge and discharge process. Moreover, a higher voltage of about 4 V can be obtained if the complex is used in an Li-ion battery.

Generation of Janus alginate hydrogel particles with magnetic anisotropy for cell encapsulation

A microfluidic approach for fabrication of Janus hydrogel particles with magnetic anisotropy is demonstrated. Using this technique, cells and magnetic beads (MBs) can be separately embedded in one hydrogel particle to maintain optical performance, and reduce the contact between cells and magnetic beads (nano- or submicron-particles). Alginate cell capsules prepared by this method can be easily controlled and manipulated by external magnetic fields and require no specific surface modification. Bio-degradability and super-paramagnetic properties of these hydrogel particles were also demonstrated experimentally.

Phase I/II study of arginine deiminase (ADI-PEG 20) in patients with advanced malignant melanoma (MM)

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Background: ADI-PEG 20 is an enzyme that degrades arginine, a crucial amino acid central to metabolism and biosynthesis of growth and development of normal and neoplastic cells. Melanoma is auxotrophic for arginine because it lacks argininosuccinate synthetase (ASS), a key enzyme required for synthesis of arginine from citrulline via the urea cycle. This study evaluates the safety and clinical efficacy of ADI-PEG 20 in patients with MM. Methods: Patients with histologically confirmed stage III (unresectable)/ IV cutaneous, uveal or mucosal MM were treated with 40, 80 or 160 IU/m2 ADI-PEG 20 i.m. weekly for 9 weeks in a phase I setting. In a phase II component, 16–25 pts receiving 160 IU/m2 will be evaluated for tumor response (TR) by RECIST. Secondary endpoints for all patients included metabolic response by 18FDG-PET, pharmacodynamics (PD), immunogenicity and ASS tumor expression by immunohistochemistry. Results: As of Nov. 2008, 24 pts were enrolled (40 IU/m2, n=6, 80 IU/m2, n=6, 160 IU/m2, n=12): 14 males, 10 females. Median age: 66 yrs (range 29- 83 yrs). Toxicity consisted primarily of Grade 1/2 adverse events (AE) (injection site pain, myalgia, arthralgia, fatigue, flushing, rash/itch, nausea, diarrhea, hyperuricemia, taste alteration). One dose limiting toxicity (DLT) of G3 arthralgia was observed at 80 IU/m2. Two DLTs (G3 seizure and G3 lymphedema) were reported, at 160 IU/m2. No grade 4 or 5 AEs were observed. Of 22 patients evaluable for TR, 8 had stable disease (SD) with 2 of these durable for ≥ 6 months. Notably, 3 SD were uveal melanoma. 14 patients had progressive disease. PD analysis showed plasma arginine depletion during study weeks 1–6 regardless of dose. Immunohistochemical ASS expression analysis in tumor tissue: negative= 13 pts, < 5% cells positive= 5 pts. Conclusions: ADI-PEG 20 as a single agent is well tolerated in advanced MM leading to consistent arginine depletion. The extent of clinical activity has yet to be shown. Combination therapy of ADI-PEG20 with other treatments such as pro-apoptotic reagents during the first 6 weeks of ADI-PEG 20 treatment while arginine is depleted could lead to synergistic anti-cancer activity.

No significant financial relationships to disclose.

Prognostic significance of leukopenia at the time of diagnosis in acute myeloid leukemia (AML)

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Background: In contrast to the poor prognosis associated with hyperleukocytosis, the prognostic significance of leukopenia at the time of diagnosis of AML is unknown. Methods: Single institution retrospective analysis of 225 consecutive, newly diagnosed AML patients (pts), homogeneously treated between July 1996 and February 2005; and divided into 2 groups based on presenting WBC: < 2,000/uL (30) and > 2,000/uL (195). Simultaneously obtained peripheral blood and marrow blasts were analyzed for cell surface expression of CD34, cKit, CXCR4, PCAM, VLA-2, VLA-3, VLA-4, VLA-5, and FLT3 using flow cytometry. Results: Patients’ characteristics (gender, secondary vs. de novo, and cytogenetic [CTG] risk) were comparable between the 2 groups. Leukopenic AML pts were older (median 56 vs. 53 years, p = 0.02), and had lower induction complete remission [CR] rates: 63% vs. 81% (p = 0.03) by univariate analysis. Induction mortality was 0% for leukopenic and 5% for non-leukopenic pts. In primary refractory pts, median survival was longer for leukopenic (11) vs. non-leukopenic (34) pts: 137 vs. 81 d (p = 0.026). Median follow-up was 22 mos. Event-free (EFS), disease-free (DFS), and overall survivals (OS) were lower in the leukopenic group: 12 vs. 14; 14 vs. 17; and 17 vs. 19 mos, respectively; but did not reach statistical significance. By multivariate analysis, age (p < 0.0001) and CTG risk group (p < 0.0001) were independent predictors of OS, while CTG risk group predicted RFS (p < 0.0001). The level of expression of cell surface adhesion molecules on blood and marrow blasts was comparable for the 2 groups. Conclusions: AML pts presenting with leukopenia have comparable outcomes to those presenting with normal or high WBC despite a lower likelihood of achieving remission. Leukopenic AML did not have over-expression of cell surface adhesion molecules.

No significant financial relationships to disclose.

Interactions between stem cells and their niche in the Drosophila ovary

The Drosophila ovary contains at least three types of active stem cells, namely, germ-line stem cells (GSCs), escort stem cells (ESCs), and follicular stem cells (FSCs), which work together to efficiently assemble egg chambers. Among the three stem cell types, the GSC is among the first shown to be controlled by the niche due to its easy identification and welldefined surrounding cells. We have shown that the niche controls GSC self-renewal, anchorage, aging, and competition, and the GSC also signals back to the niche for its maintenance. The FSC is an attractive model for studying epithelial stem cell regulation and signal integration because we have shown that it resembles mammalian epithelial stem cells and requires multiple signaling pathways for its self-renewal. In this chapter, we have highlighted the findings of our studies on interactions between Drosophila ovarian stem cells and their niches during normal development and aging and on stem cell competition for niche occupancy. We further discuss their implications in general stem cell biology and future directions in this exciting area.

Mucosal insulin vaccination for type 1 diabetes prevention

Mucosal administration of autoantigen, if efficacious, is an attractive therapeutic approach for prevention of type 1 diabetes. It can prevent or delay autoimmune diabetes in animal models, but although shown to be safe has not yet been proven effective in human studies. Efficacy may depend upon the dose and route at which antigen is administered, the stage in type 1 diabetes pathogenesis at which treatment is initiated, and the study cohort that is treated. Here we address these issues and propose a clinical translation possibility for mucosal insulin administration in genetically at risk individuals.