Functionally stable and phylogenetically diverse microbial enrichments from microbial fuel cells during wastewater treatment

Microbial fuel cells (MFCs) are devices that exploit microorganisms as biocatalysts to recover energy from organic matter in the form of electricity. One of the goals of MFC research is to develop the technology for cost-effective wastewater treatment. However, before practical MFC applications are implemented it is important to gain fundamental knowledge about long-term system performance, reproducibility, and the formation and maintenance of functionally-stable microbial communities. Here we report findings from a MFC operated for over 300 days using only primary clarifier effluent collected from a municipal wastewater treatment plant as the microbial resource and substrate. The system was operated in a repeat-batch mode, where the reactor solution was replaced once every two weeks with new primary effluent that consisted of different microbial and chemical compositions with every batch exchange. The turbidity of the primary clarifier effluent solution notably decreased, and 97% of biological oxygen demand (BOD) was removed after an 8-13 day residence time for each batch cycle. On average, the limiting current density was 1000 mA/m(2), the maximum power density was 13 mW/m(2), and coulombic efficiency was 25%. Interestingly, the electrochemical performance and BOD removal rates were very reproducible throughout MFC operation regardless of the sample variability associated with each wastewater exchange. While MFC performance was very reproducible, the phylogenetic analyses of anode-associated electricity-generating biofilms showed that the microbial populations temporally fluctuated and maintained a high biodiversity throughout the year-long experiment. These results suggest that MFC communities are both self-selecting and self-optimizing, thereby able to develop and maintain functional stability regardless of fluctuations in carbon source(s) and regular introduction of microbial competitors. These results contribute significantly toward the practical application of MFC systems for long-term wastewater treatment as well as demonstrating MFC technology as a useful device to enrich for functionally stable microbial populations.     

MAOA, MTHFR, and TNF-β genes polymorphisms and personality traits in the pathogenesis of migraine

Migraine is a multifactorial disease with various factors, such as genetic polymorphisms and personality traits, but the contribution of those factors is not clear. To clarify the pathogenesis of migraine, the contributions of genetic polymorphisms and personality traits were simultaneously investigated using multivariate analysis. Ninety-one migraine patients and 119 non-headache healthy volunteers were enrolled. The 12 gene polymorphisms analysis and NEO-FFI personality test were performed. At first, the univariate analysis was performed to extract the contributing factors to pathogenesis of migraine. We then extracted the factors that independently contributed to the pathogenesis of migraine using multivariate stepwise logistic regression analysis. Using the multivariate analysis, three gene polymorphisms including monoamine oxidase A (MAOA) T941G, methylenetetrahydrofolate reductase (MTHFR) C677T, and tumor necrosis factor beta (TNF-β) G252Α, and the neuroticism and conscientiousness scores in NEO-FFI were selected as significant factors that independently contributed to the pathogenesis of migraine. Their odds ratios were 1.099 (per point of neuroticism score), 1.080 (per point of conscientiousness score), 2.272 (T and T/T or T/G vs G and G/G genotype of MAOA), 1.939 (C/T or T/T vs C/C genotype of MTHFR), and 2.748 (G/A or A/A vs G/G genotype of TNF-β), respectively. We suggested that multiple factors, such as gene polymorphisms and personality traits, contribute to the pathogenesis of migraine. The contribution of polymorphisms, such as MAOA T941G, MTHFR C677T, and TNF-β G252A, were more important than personality traits in the pathogenesis of migraine, a multifactorial disorder.     

CD2AP/SHIP1 complex positively regulates plasmacytoid dendritic cell receptor signaling by inhibiting the E3 ubiquitin ligase Cbl

The human plasmacytoid dendritic cell (pDC) receptor BDCA2 forms a complex with the adaptor FcεR1γ to activate an ITAM-signaling cascade. BDCA2 receptor signaling negatively regulates the TLR7/9-mediated type 1 IFN responses in pDCs, which may play a key role in controlling self-DNA/RNA-induced autoimmunity. We report in this article that CD2-associated adaptor protein (CD2AP), which is highly expressed in human pDCs, positively regulates BDCA2/FcεR1γ receptor signaling. By immunoprecipitation and mass spectrometry analyses, we found that CD2AP bound to SHIP1. Knockdown of CD2AP or SHIP1 reduced the BDCA2/FcεR1γ-mediated ITAM signaling and blocked its inhibition of TLR9-mediated type 1 IFN production. Knockdown of CD2AP or SHIP1 also enhanced the ubiquitination and degradation of Syk and FcεR1γ that was mediated by the E3 ubiquitin ligase Cbl. This led us to discover that, upon BDCA2 cross-linking, the CD2AP/SHIP1 complex associated with Cbl and inhibited its E3 ubiquitin ligase activity. In human primary pDCs, cross-linking of the BDCA2/FcεR1γ complex induced the recruitment of the CD2AP/SHIP1/Cbl complex to the plasma membrane of pDCs, where it colocalized with the BDCA2/FcεR1γ complex. Therefore, CD2AP positively regulates BDCA2/FcεR1γ signaling by forming a complex with SHIP1 to inhibit the E3 ubiquitin ligase Cbl.     

Maintenance of gonadotrophs in pituitary autografts under the kidney capsules of female rats given sex hormones or LRH

Female Sprague-Dawley rats were hypophysectomized and the anterior pituitary gland was immediately placed under the kidney capsule. For 1 week after surgery, groups of pituitary autograft-bearing animals were treated with twice-daily injections of estradiol 17 beta (E), progesterone (P), estradiol 17 beta and progesterone (EP), or luteinizing hormone-releasing hormone (LRH). Within 2--4 hours following the last injection, the pituitary grafts were removed and placed into organ culture. They were maintained in culture with or without added LRH (10(-7) M) for 1 hour at 37 degrees C. The culture media were then frozen for later radioimmunoassay of FSH and LH. The tissues were kept in culture for an additional 24 hours, at which time they were fixed and prepared for immunocytochemistry or electron microscopy. Results showed that treatment of the animals with E, EP, or LRH enhanced the release of FSH and LH into the culture media, and that the release of these hormones was increased further by acute incubation with LRH. The ultrastructure of the gonadotrophs was well maintained by treating the animals with E or the combination of E and P or with LRH. Graft tissue from animals treated with LRH, which was incubated subsequently for 24 hours with LRH, showed the best maintenance of gonadotroph morphology. This experimental procedure should be useful for obtaining gonadotrophs for use in establishing gonadotroph cell lines.     

Solid-phase oligosaccharide synthesis and related technologies

Research efforts directed at the development of methodologies effective for solid-phase synthesis of oligosaccharides have resulted in a number of impressive achievements. In addition, closely related technologies, such as soluble polymer-supported synthesis and fluorous synthesis of the same class of molecules, have proved to be quite promising.