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live-Cell Imaging of Dual-labeled Golgi Stacks in Tobacco BY-2 Cells Reveals Similar Behaviors for Different Cisternae during Movement and Brefeldin A Treatment

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Molecular Plant 2011年第5期4卷 896-908页

作者： stephanie l. Madison Andreas Nebenfuhr Department of Biochemistry and Cellular and Molecular Biology University of Tennessee Knoxville TN 37996-0840 USA

In plant cells, the Golgi apparatus consists of numerous stacks that, in turn, are composed of several flattened cisternae with a clear cis-to-trans polarity. During normal functioning within living cells, this unusual organelle displays a wide range of dynamic behaviors such as whole stack motility, constant membrane flux through the cisternae, and Golgi enzyme recycling through the ER. In order to further investigate various aspects of Golgi stack dynamics and integrity, we co-expressed pairs of established Golgi markers in tobacco BY-2 cells to distinguish sub-compartments of the Golgi during monensin treatments, movement, and brefeldin A （BFA）-induced disassembly. A combination of cis and trans markers revealed that Golgi stacks remain intact as they move through the cytoplasm. The Golgi stack orientation during these movements showed a slight preference for the cis side moving ahead, but trans cisternae were also found at the leading edge. During BFA treatments, the different sub-compartments of about half of the observed stacks fused with the ER sequentially; however, no consistent order could be detected. In contrast, the ionophore monensin resulted in swelling of trans cisternae while medial and particularly cis cisternae were mostly unaffected. Our results thus demonstrate a re- markable equivalence of the different cisternae with respect to movement and BFA-induced fusion with the ER. In addi- tion, we propose that a combination of dual-label fluorescence microscopy and drug treatments can provide a simple alternative approach to the determination of protein localization to specific Golgi sub-compartments.

关键词： Golgi apparatus Golgi stack integrity brefeldin A monensin tobacco BY-2 cells live-cell imaging.

Increased working voltage of hexamine-coated porous carbon for supercapacitors

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Science Bulletin 2015年第18期60卷 1587-1597页

作者： stephanie l.Candelaria Guozhong Cao Department of Materials Science and Engineering University of Washington

Highly porous carbon, both unmodified and hexamine-coated on the pore surfaces, is tested at high working voltages in organic electrolyte for supercapacitors in order to enhance the energy density and power ***–gel processing allows for excellent control of the porous structure and chemical composition of carbon,resulting in a material with high surface area and a low level of impurities. This porous carbon can be modified using a simple solution-based method to enhance capacitance. Increasing the working voltage from 2.0 to 3.0 V significantly improves performance for both unmodified and hexamine-coated carbon. The energy density and power density increase at higher working voltage, and under certain conditions, the capacitance increases as *** stability is also investigated, with hexamine-coated carbon retaining more of its initial capacitance than unmodified carbon at all working voltages.

关键词： Supercapacitor High voltage Porouscarbon Hexamine Surface modification Nitrogen

The gut microbiome: an orchestrator of xenobiotic metabolism

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Acta Pharmaceutica Sinica B 2020年第1期10卷 19-32页

作者： stephanie l.Collins Andrew D.Patterson Department of Biochemistry Microbiologyand Molecular Biologythe Pennsylvania State UniversityUniversity ParkPA 16802USA Department of Veterinary and Biomedical Science the Pennsylvania State UniversityUniversity ParkPA 16802USA

Microbes inhabiting the intestinal tract of humans represent a site for xenobiotic *** gut microbiome,the collection of microorganisms in the gastrointestinal tract,can alter the metabolic outcome of pharmaceuticals,environmental toxicants,and heavy metals,thereby changing their *** chemical modification of xenobiotics by the gut microbiome,either through the intestinal tract or re-entering the gut via enterohepatic circulation,can lead to increased metabolism or bioactivation,depending on the enzymatic activity within the microbial *** enzymes encoded within the microbiome include those that reverse the modifications imparted by host detoxification ***,the microbiome can limit xenobiotic absorption in the small intestine by increasing the expression of cell-cell adhesion proteins,supporting the protective mucosal layer,and/or directly sequestering ***,host gene expression is regulated by the microbiome,including CYP450s,multi-drug resistance proteins,and the transcription factors that regulate *** the microbiome affects the host and pharmacokinetics of the xenobiotic,xenobiotics can also influence the viability and metabolism of the *** understanding of the complex interconnectedness between host,microbiome,and metabolism will advance with new modeling systems,technology development and refinement,and mechanistic studies focused on the contribution of human and microbial metabolism.

关键词： Gut microbiome Xenobiotic metabolism Absorption Gastrointestinal tract Pharmacokinetics Enterohepatic circulation Bioactivation

leaf size versus leaf numbertradeoffs in dioecious angiosperms

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Journal of Plant Ecology 2013年第1期6卷 29-35页

作者： stephanie l.Scott lonnie W.Aarssen Department of Biology Queen’s UniversityKingstonOntarioCanada K7L 3N6

Aims We explore the possible role of leaf size/number trade-offs for the interpretation of leaf size dimorphism in dioecious plant *** Total above-ground biomass(both male and female)for three herbaceous dioecious species and individual shoots(from both male and female plants)for three woody dioecious species were sampled to record individual leaf dry mass,number of leaves,dry mass of residual above-ground tissue(all remaining non-leaf biomass),number of flowers/inflorescences(for herbaceous species)and number of *** Findings For two out of three woody species and two out of three herbaceous species examined,male plants produced smaller leaves but with higher leafing intensity—*** leaves per unit of supporting(residual)shoot tissue or plant body mass—compared with *** and female plants,however,did not differ in shoot or plant body mass or branching *** interpret these results as possible evidence for a dimorphic leaf deployment strategy that promotes both male and female function,*** male plants,capacity as a pollen donor may be favored by selection for a broadly spaced floral display,hence favoring relatively high leafing intensity because this provides more numerous axillary meristems that can be deployed for flowering,thus requiring a relatively small leaf as a *** one herbaceous species,higher leafing intensity in males was associated with greater flower production than in *** contrast,in female plants,selection favors a relatively large leaf,we propose,because this promotes greater capacity for localized photosynthate production,thus supporting the locally high energetic cost of axillary fruit and seed development,which in turn requires a relatively low leafing intensity as a trade-off.

关键词： bud bank leaf dimorphism leafing intensity dioecy

CdS quantum dot aerogels for photocatalytic hydrogen evolution

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Nano Research 2024年第12期17卷 10292-10301页

作者： Vinicius Alevato Daniel Streater Cole Premtaj Jier Huang stephanie l.Brock Department of Chemistry Wayne State UniversityDetroitMI 48202USA Department of Chemistry Marquette UniversityMilwaukeeWI 53201USA Department of Chemistry&Shiller Institute for Integrated Science and Society Boston CollegeBostonMA 02467USA

CdS quantum dots(QDs)have been extensively studied as photocatalysts and sensitizers for visible-light-driven water ***,their efficiencies are limited by the need to accumulate sufficient redox equivalents to produce_(H2)and consequent photocorrosion associated with slow hole-transfer *** address these limitations,we report the formation of CdS QD assemblies(aerogels,AGs)capable of facilitating energy/charge transport between individual QDs,and evaluate their performance as photocatalysts for hydrogen evolution as a function of structure,wurtzite(w-)***(zb-),and different annealing *** formation of AGs from QDs resulted in increased rates of_(H2)production under visible light illumination:from 1458(QD)to 6650(AG)μmol_(H2)·h^(-1)·g^(-1)on zbCdS and from 1221(QD)to 3325(AG)μmol_(H2)·h^(-1)·g^(-1)on *** is attributed to exciton delocalization between adjacent QDs facilitating charge/energy *** processing of CdS AGs up to 250℃ improved their activity,increasing the degree of exciton delocalization,while annealing them to 300℃ caused sintering of the primary QD particles within the AGs and a decrease in activity associated with loss in surface *** best photocatalyst,zbCdS AG annealed at 250℃,had an average_(H2)production rate of 13,604±2017μmol_(H2)·h^(-1)·g^(-1),an apparent quantum yield of 2.8%at 425±12.5 nm,and was stable for 2 h before beginning to deactivate due to *** study confirms the potential of CdS AGs as matrixes for the design of more active and stable composite photocatalysts for water splitting.

关键词： sol-gel chemistry photocorrosion apparent quantum yield wurtzite zinc blende

Role of farnesoid X receptor in establishment of ontogeny of phase-I drug metabolizing enzyme genes in mouse liver

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Acta Pharmaceutica Sinica B 2016年第5期6卷 453-459页

作者： lai Peng stephanie Piekos Grace l.Guo Xiao-bo Zhong Department of Pharmaceutical Sciences School of PharmacyUniversity of Connecticut Key laboratory of System Biomedicine Center for Comparative BiomedicineInstitute of Systems BiomedicineShanghai Jiao Tong University Department of Pharmacology and Toxicology School of PharmacyRutgers University

The expression of phase-I drug metabolizing enzymes in liver changes dramatically during postnatal liver *** X receptor(FXR) is critical for bile acid and lipid homeostasis in ***,the role of FXR in regulating ontogeny of phase-I drug metabolizing genes is not ***,we applied RNA-sequencing to quantify the developmental expression of phase-I genes in both Fxr-null and control(C57Bl/6) mouse livers during *** samples of male C57Bl/6 and Fxr-null mice at6 different ages from prenatal to adult were *** Fxr-null showed an overall effect to diminish the "day-1 surge" of phase-I gene expression,including cytochrome P450 s at neonatal *** the 185 phase-I genes from 12 different families,136 were expressed,and differential expression during development occurred in genes from all 12 phase-I families,including hydrolysis: carboxylesterase(Ces),paraoxonase(Pon),and epoxide hydrolase(Ephx); reduction: aldoketo reductase(Akr),quinone oxidoreductase(Nqo),and dihydropyrimidine dehydrogenase(Dpyd); and oxidation: alcohol dehydrogenase(Adh),aldehyde dehydrogenase(Aldh),flavin monooxygenases(Fmo),molybdenum hydroxylase(Aox and Xdh),cytochrome P450(P450),and cytochrome P450 oxidoreductase(Por).The data also suggested new phase-I genes potentially targeted by *** results revealed an important role of FXR in regulation of ontogeny of phase-I genes.

关键词： Drug metabolizing enzymes Farnesoid X receptor liver Ontogeny Fxr-null mouse Gene expression

Postphalloplasty urinary function test:an observational study of novel outcome instrument to capture urinary dysfunction and quality of life after phalloplasty

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Asian Journal of Andrology 2022年第6期24卷 570-574页

作者： James l liu lauren Eisenbeis stephanie Preston Arthur l Burnett Heather N DiCarlo Devin Coon The James Buchanan Brady Urological Institute and Department of Urology Johns Hopkins University School of MedicineBaltimoreMD 21287USA Department of Plastic and Reconstructive Surgery Johns Hopkins School of MedicineBaltimoreMD 21287USA Johns Hopkins Center for Transgender Health Johns Hopkins MedicineBaltimoreMD 21287USA Department of Surgery University of Texas SouthwesternDallasTX 75370USA

Due to growing social acceptance,there has been an increasing number of gender-affirmation surgeries performed in North *** research in this patient population focuses on surgical outcomes and advancing ***,little work has been done to study functional *** better evaluate urinary dysfunction in the postphalloplasty trans men patient population,our group developed a novel patient-reported outcome instrument-the postphalloplasty urinary function test(PP UFT)and protocol to measure postvoid urethral volume(PVUR),and we present our preliminary *** conducted a cross-sectional pilot study in a cohort of 15 adult trans men who had undergone phalloplasty with urethral lengthening surgery between 2018 and *** had stable urinary function via the neophallus at the time of *** filled out the PP UFT and were asked to record their PVUR as per our *** average PP UFT score was 8.9 out of 40 and the average quality-of-life(QOl)score was *** dribbling constituted the major complaint and on average comprised 63.2%of the reported PP UFT *** average PVUR was 2.2 ml(range:0.5-5.6 ml).There was a positive correlation between higher PP UFT and worse-reported quality of life(Ple urology have limitations for accurately capturing urinary dysfunction in this specific patient *** combination of PP UFT and PVUR measurement offers potential for quantifying urinary function and quality of life in patients who undergo *** studies will validate these instruments.

关键词： gender affirmation gender surgery phalloplasty postvoid urethral residual urethral lengthening urinary dysfunction

Androgens and prostate disease

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Asian Journal of Andrology 2014年第2期16卷 248-255,I0009页

作者： lori A Cooper stephanie T Page Departments of Medicine Division of Endocrinology and Metabolism University of Washington Seattle University of Washington and Harborview Medical Center Seattle Washington USA.

A growing body of literature has established the anabolic benefits of testosterone （T） therapy in hypogonadal men. However, there remains a paucity of data regarding the risks of exogenous androgen use in older men and the potential for adverse effects on the prostate gland. Whether T therapy in older, hypogonadal men might worsen lower urinary tract symptoms or exacerbate, unmask, or even incite prostate cancer development has tempered enthusiasm for T therapy, while known prostatic disease has served as a relative contraindication to T therapy. Androgens are necessary for the development and maintenance of the prostate gland. However, epidemiologic studies do not consistently find a positive relationship between endogenous serum androgen concentrations and the risk of prostate disease. Recent data demonstrate that 5α-reductase inhibitors decrease the risk of low-grade prostate cancer, suggesting that modifying androgen metabolism may have beneficial effects on prostate health, yet similar reductions in high-grade disease have not been observed, thereby questioning the true clinical benefits of these agents for chemoprevention. Knowing how to best investigate the relationship between androgens and the development of prostate disease given the lack of large, randomized trials is difficult. Accumulating data challenges the assumption that alterations in serum androgens have parallel effects within the prostate hormonal environment or change androgen-regulated processes within the gland. long-term intervention studies are needed to truly ascertain the effects of androgen manipulation on prostate tissue and disease risk. However, available data do not support the notion that restoring serum androgens to normal physiologic ranges drives prostate disease.

关键词： androgens male hypogonadism prostate testosterone

Circadian Clock-Regulated Phosphate Transporter PHT4;1 Plays an Important Role in Arabidopsis Defense

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Molecular Plant 2011年第3期4卷 516-526页

作者： Guo-Ying Wang Jiang-li Shi Gina Ng stephanie l. Battle Chong Zhang Hua lu Department of Biological Sciences University of Maryland Baltimore County 1000 Hilltop CircLe Baltimore MD 21250 USA

The Arabidopsis accelerated cell death 6-1 （acd6-1） mutant shows constitutive defense, cell death, and ex- treme dwarf phenotypes. In a screen for acd6-1 suppressors, we identified a mutant that was disrupted by a T-DNA in the PHOSPHATE TRANSPORTER 4;1 （PHT4;1） gene. The suppressor mutant pht4;1-1 is dominant, expresses truncated PHT4;1 transcripts, and is more susceptible to virulent Pseudomonas syringae strains but not to several avirulent strains. Treat- ment with a salicylic acid （SA） agonist induced a similar level of resistance in Col-0 and pht4;1-1, suggesting that PHT4;1 acts upstream of the SA pathway. Genetic analysis further indicates that PHT4,1 contributes to SID2-dependent and -in- dependent pathways. Transgenic expression of the DNA fragment containing the PHT4;1-1 region or the full-length PHT4;1 gene in wild-type conferred enhanced susceptibility to Pseudomonas infection. Interestingly, expression of PHT4;1 is reg- ulated by the circadian clock. Together, these data suggest that the phosphate transporter PHT4;1 is critical for basal defense and also implicate a potential role of the circadian clock in regulating innate immunity of Arabidopsis.

关键词： Biological clock disease resistance signal transduction Pseudomonas syringae phosphate transporter salicylic acid.