129 research outputs found

    The Acquisition of Plastids/Phototrophy in Heterotrophic Dinoflagellates

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    Several dinoflagellates are known to practice acquired phototrophy by either hosting intact algal endosymbionts or retaining plastids. The acquisition of phototrophy in dinoflagellates appears to occur independently over a variety of orders, rather than being restricted to any specific order(s). While dinoflagellates with intact algal cells host endosymbionts of cyanobacteria, pelagophyte, prasinophyte or dictyochophyte, most organelle-retaining dinoflagellates acquire plastids from cryptophytes. In dinoflagellates with acquired phototrophy, the mechanism by which symbionts or plastids are obtained has not been well studied at sub-cellular or ultrastructural level, and thus little is known regarding their mechanism to sequester and maintain photosynthetic structures, except for three cases, Amphidinium poecilochroum, Gymnodinium aeruginosum, and Dinophysis caudata with peduncle feeding. Dinoflagellates with acquired phototrophy display different degrees of reduction of the retained endosymbiont and organelles, ranging from those which contain intact whole algal cells (e.g. green Noctiluca scintillans), to those which have retained almost a full complement of organelles (e.g., Amphidinium poecilochroum and Podolampas bipes), to those in which only the plastids remain (e.g., Amphidinium wigrense and Dinophysis spp.). A series of events leading to acquisition and subsequent degeneration of a whole-cell endosymbiont have been widely recognized as evolutionary pathway of the acquisition of plastids. However, recent work on D. caudata suggests that acquisition of phototrophy by predation (i.e. kleptoplastidy) may be a mechanism and evolutionary pathway through which plastids originated in dinoflagellates with ‘foreign’ plastids other than the ‘typical’ peridinin-type plastids. Most organelle-retaining dinoflagellates are facultative mixotrophs, with Dinophysis species and an undescribed Antarctic dinoflagellate being the only obligate mixotrophs known so far. The establishment of dinoflagellates with acquired phototrophy in cultures and careful research using the cultures would help improve our knowledge of the evolution of the dinoflagellate plastids and their ecophysiology

    Emergent Properties of a Market-based Digital Library with Strategic Agents

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    The University of Michigan Digital Library (UMDL) is designed as an open system that allows third parties to build and integrate their own profit-seeking agents into the marketplace of information goods and services. The profit-seeking behavior of agents, however, risks inefficient allocation of goods and services, as agents take strategic stances that might backfire. While it would be good if we could impose mechanisms to remove incentives for strategic reasoning, this is not possible in the UMDL. Therefore, our approach has instead been to study whether encouraging the other extreme—making strategic reasoning ubiquitous—provides an answer.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43993/1/10458_2004_Article_251209.pd

    Ethanol extract of Scutellaria baicalensis Georgi prevents oxidative damage and neuroinflammation and memorial impairments in artificial senescense mice

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    Aging is a progressive process related to the accumulation of oxidative damage and neuroinflammation. We tried to find the anti-amnesic effect of the Scutellaria baicalens Georgia (SBG) ethanol extract and its major ingredients. The antioxidative effect of SBG on the mice model with memory impairment induced by chronic injection of D-galactose and sodium nitrate was studied. The Y-maze test was used to evaluate the learning and memory function of mice. The activities of superoxide dismutase, catalase and the content of malondialdehyde in brain tissue were used for the antioxidation activities. Neuropathological alteration and expression of bcl-2 protein were investigated in the hippocampus by immunohistochemical staining. ROS, neuroinflammation and apoptosis related molecules expression such as Cox-2, iNOS, procaspase-3, cleaved caspase-3, 8 and 9, bcl-2 and bax protein and the products of iNOS and Cox-2, NO, PGE2, were studied using LPS-activated Raw 264.7 cells and microglia BV2 cells. The cognition of mice was significantly improved by the treatment of baicalein and 50 and 100 mg/kg of SBG in Y-maze test. Both SBG groups showed strong antioxidation, antiinflammation effects with significantly decreased iNOS and Cox-2 expression, NO and PGE2 production, increased bcl-2 and decreased bax and cleaved caspase-3 protein expression in LPS induced Raw 264.7 and BV2 cells. We also found that apoptotic pathway was caused by the intrinsic mitochondrial pathway with the decreased cleaved caspase-9 and unchanged cleaved caspase-8 expression. These findings suggest that SBG, especially high dose, 100 mg/kg, improved the memory impairments significantly and showed antioxidation, antiinflammation and intrinsic caspase-mediated apoptosis effects

    Effects of Gyejibongnyeong-hwan on dysmenorrhea caused by blood stagnation: study protocol for a randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Gyejibongnyeong-hwan (GJBNH) is one of the most popular Korean medicine formulas for menstrual pain of dysmenorrhea. The concept of blood stagnation in Korean medicine is considered the main factor of causing abdominal pain, or cramps, during menstrual periods. To treat the symptoms, GJBNH is used to fluidify the stagnated blood and induce the blood flow to be smooth, reducing pain as the result. The purpose of this trial is to identify the efficacy of GJBNH in dysmenorrhea caused by blood stagnation.</p> <p>Methods</p> <p>This study is a multi-centre, randomised, double-blind, controlled trial with two parallel arms: the group taking GJBNH and the group taking placebo. 100 patients (women from age 18 to 35) will be enrolled to the trial. Through randomization 50 patients will be in experiment arm, and the other 50 patients will be in control arm. At the second visit (baseline), all participants who were already screened that they fulfil both the inclusion and the exclusion criteria will be randomised into two groups. Each group will take the intervention three times per day during two menstrual cycles. After the treatment for two cycles, each patient will be followed up during their 3<sup>rd</sup>, 4<sup>th </sup>and 5<sup>th </sup>menstrual cycles. From the screening (Visit 1) through the second follow-up (Visit 6) the entire process will take 25 weeks.</p> <p>Discussion</p> <p>This trial will provide evidence for the effectiveness of GJBNH in treating periodical pain due to dysmenorrhea that is caused by blood stagnation. The primary outcome between the two groups will be measured by changes in the Visual Analogue Score (VAS) of pain. The secondary outcome will be measured by the Blood Stagnation Scale, the Short-form McGill questionnaire and the COX menstrual symptom scale. Analysis of covariance (ANCOVA) and repeated measured ANOVA will be used to analyze the data analysis.</p> <p>Trial registration</p> <p>Current Controlled Trials: <a href="http://www.controlled-trials.com/ISRCTN30426947">ISRCTN30426947</a></p

    Effects and Safety of Gyejibongnyeong-Hwan on Dysmenorrhea Caused by Blood Stagnation: A Randomized Controlled Trial

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    Objective. This study was a multicenter, randomized, double-blind, and controlled trial with two parallel arms: the GJBNH group and the placebo group. This trial recruited 100 women aging 18 to 35 years with primary dysmenorrhea caused by blood stagnation. The investigational drugs, GJBNH or placebo, were administered for two menstrual periods (8 weeks) to the participants three times per day. The participants were followed up for two menstrual cycles after the administration. Results. The results were analyzed by the intention-to-treat (ITT) dataset and the per-protocol (PP) dataset. In the ITT dataset, the change of the average menstrual pain VAS score in the GJBNH group was statistically significantly lower than that in the control group. Significant difference was not observed in the SF-MPQ score change between the GJBNH group and the placebo group. No significant difference was observed in the PP analyses. In the follow-up phase, the VAS scores of the average menstrual pain and the maximum menstrual pain continually decreased in the placebo group, but they increased in the GJBNH group. Conclusion. GJBNH treatment for eight weeks improved the pain of the dysmenorrhea caused by blood stagnation, but it should be successively administered for more than two menstrual cycles. Trial Registration. This trial is registered with Current Controlled Trials no. ISRCTN30426947

    Effective treatment of ductal carcinoma in situ with a HER-2-targeted alpha-particle emitting radionuclide in a preclinical model of human breast cancer

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    The standard treatment for ductal carcinoma in situ (DCIS) of the breast is surgical resection, followed by radiation. Here, we tested localized therapy of DCIS in mice using the immunoconjugate 225Ac linked-trastuzumab delivered through the intraductal (i.duc) route. Trastuzumab targets HER-2/neu, while the alpha-emitter 225Ac (half-life, 10 days) delivers highly cytotoxic, focused doses of radiation to tumors. Systemic 225Ac, however, elicits hematologic toxicity and at high doses free 213Bi, generated by its decay, causes renal toxicity. I.duc delivery of the radioimmunoconjugate could bypass its systemic toxicity. Bioluminescent imaging showed that the therapeutic efficacy of intraductal 225Ac-trastuzumab (10-40 nCi per mammary gland; 30-120 nCi per mouse) in a DCIS model of human SUM225 cancer cells in NSG mice was significantly higher (p<0.0003) than intravenous (120 nCi per mouse) administration, with no kidney toxicity or loss of body weight. Our findings suggest that i.duc radioimmunotherapy using 225Ac-trastuzumab deserves greater attention for future clinical development as a treatment modality for early breast cancer
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