115 research outputs found

    A Dihydroxo-Bridged Ferric Dimer

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    Recent investigations have produced a large number of dimeric complexes containing the oxo-bridged structural unit Fe_2O^(4+). Here we report the isolation and characterization of [Fe (pic)_2OH]_2 which apparently is the first example of a crystalline iron(III) dimer which utilizes dihydroxo bridging in its coordination structure

    Role of choline deficiency in the fatty liver phenotype of mice fed a low protein, very low carbohydrate ketogenic diet

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    Though widely employed for clinical intervention in obesity, metabolic syndrome, seizure disorders and other neurodegenerative diseases, the mechanisms through which low carbohydrate ketogenic diets exert their ameliorative effects still remain to be elucidated. Rodent models have been used to identify the metabolic and physiologic alterations provoked by ketogenic diets. A commonly used rodent ketogenic diet (Bio-Serv F3666) that is very high in fat (~94% kcal), very low in carbohydrate (~1% kcal), low in protein (~5% kcal), and choline restricted (~300 mg/kg) provokes robust ketosis and weight loss in mice, but through unknown mechanisms, also causes significant hepatic steatosis, inflammation, and cellular injury. To understand the independent and synergistic roles of protein restriction and choline deficiency on the pleiotropic effects of rodent ketogenic diets, we studied four custom diets that differ only in protein (5% kcal vs. 10% kcal) and choline contents (300 mg/kg vs. 5 g/kg). C57BL/6J mice maintained on the two 5% kcal protein diets induced the most significant ketoses, which was only partially diminished by choline replacement. Choline restriction in the setting of 10% kcal protein also caused moderate ketosis and hepatic fat accumulation, which were again attenuated when choline was replete. Key effects of the 5% kcal protein diet - weight loss, hepatic fat accumulation, and mitochondrial ultrastructural disarray and bioenergetic dysfunction - were mitigated by choline repletion. These studies indicate that synergistic effects of protein restriction and choline deficiency influence integrated metabolism and hepatic pathology in mice when nutritional fat content is very high, and support the consideration of dietary choline content in ketogenic diet studies in rodents to limit hepatic mitochondrial dysfunction and fat accumulation

    Children’s comprehension of informational text: Reading, engaging, and learning

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    The Reading, Engaging, and Learning project (REAL) investigated whether a classroom intervention that enhanced young children's experience with informational books would increase reading achievement and engagement. Participants attended schools serving low income neighborhoods with 86% African American enrollment. The longitudinal study spanned second through fourth grades. Treatment conditions were: (1) Text Infusion/Reading for Learning Instruction -- students were given greater access to informational books in their classroom libraries and in reading instruction; (2) Text Infusion Alone -- the same books were provided but teachers were not asked to alter their instruction; (3) Traditional Instruction -- students experienced business as usual in the classroom. Children were assessed each year on measures of reading and reading engagement, and classroom instructional practices were observed. On most measures, the informational text infusion intervention did not yield differential growth over time. However, the results inform efforts to increase children’s facility with informational text in the early years in order to improve reading comprehension

    Gut Microbial Trimethylamine Is Elevated in Alcohol-Associated Hepatitis and Contributes to Ethanol-Induced Liver Injury in Mice

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    There is mounting evidence that microbes residing in the human intestine contribute to diverse alcohol-associated liver diseases (ALD) including the most deadly form known as alcohol-associated hepatitis (AH). However, mechanisms by which gut microbes synergize with excessive alcohol intake to promote liver injury are poorly understood. Furthermore, whether drugs that selectively target gut microbial metabolism can improve ALD has never been tested. We used liquid chromatography tandem mass spectrometry to quantify the levels of microbe and host choline co-metabolites in healthy controls and AH patients, finding elevated levels of the microbial metabolite trimethylamine (TMA) in AH. In subsequent studies, we treated mice with non-lethal bacterial choline TMA lyase (CutC/D) inhibitors to blunt gut microbe-dependent production of TMA in the context of chronic ethanol administration. Indices of liver injury were quantified by complementary RNA sequencing, biochemical, and histological approaches. In addition, we examined the impact of ethanol consumption and TMA lyase inhibition on gut microbiome structure via 16S rRNA sequencing. We show the gut microbial choline metabolite TMA is elevated in AH patients and correlates with reduced hepatic expression of the TMA oxygenase flavin-containing monooxygenase 3 (FMO3). Provocatively, we find that small molecule inhibition of gut microbial CutC/D activity protects mice from ethanol-induced liver injury. CutC/D inhibitor-driven improvement in ethanol-induced liver injury is associated with distinct reorganization of the gut microbiome and host liver transcriptome. The microbial metabolite TMA is elevated in patients with AH, and inhibition of TMA production from gut microbes can protect mice from ethanol-induced liver injury

    Isolation and Characterization of Human Trophoblast Side-Population (SP) Cells in Primary Villous Cytotrophoblasts and HTR-8/SVneo Cell Line

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    Recently, numerous studies have identified that immature cell populations including stem cells and progenitor cells can be found among “side-population” (SP) cells. Although SP cells isolated from some adult tissues have been reported elsewhere, isolation and characterization of human trophoblast SP remained to be reported. In this study, HTR-8/SVneo cells and human primary villous cytotrophoblasts (vCTBs) were stained with Hoechst 33342 and SP and non-SP (NSP) fractions were isolated using a cell sorter. A small population of SP cells was identified in HTR-8/SVneo cells and in vCTBs. SP cells expressed several vCTB-specific markers and failed to express syncytiotrophoblast (STB) or extravillous cytotrophopblast (EVT)-specific differentiation markers. SP cells formed colonies and proliferated on mouse embryonic fibroblast (MEF) feeder cells or in MEF conditioned medium supplemented with heparin/FGF2, and they also showed long-term repopulating property. SP cells could differentiate into both STB and EVT cell lineages and expressed several differentiation markers. Microarray analysis revealed that IL7R and IL1R2 were exclusively expressed in SP cells and not in NSP cells. vCTB cells sorted as positive for both IL7R and IL1R2 failed to express trophoblast differentiation markers and spontaneously differentiated into both STB and EVT in basal medium. These features shown by the SP cells suggested that IL7R and IL1R2 are available as markers to detect the SP cells and that vCTB progenitor cells and trophoblast stem cells were involved in the SP cell population

    Controlling Destiny through Chemistry: Small-Molecule Regulators of Cell Fate

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    U. S. Fourth Graders’ Informational Text Comprehension: Indicators from NAEP

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    This study is a secondary analysis of reading data collected from over 165,000 fourth graders as part of the U.S. National Assessment of Educational Progress. Using hierarchical linear modelling, the authors investigated factors associated with students’ informational text comprehension, including out-of-school reading engagement, and in-school measures of cross-curricular reading, discussion about reading, and reading-related activities (e.g., book reports, projects). In addition, this study examined the interactions between these factors, informational text comprehension, and students’ eligibility for Free and Reduced Priced Meals (FARMS). There were positive associations between students’ informational text comprehension and their reading engagement, cross-curricular reading, and discussion about reading. However, reading-related experiences were associated with lower than expected scores. In addition, out-of-school reading engagement and in-school reading experiences may not be associated with informational reading comprehension to the same degree for the most at-risk U.S. students, as most results differed in strength of association for FARMS-eligible students

    Simultaneous pair electronic excitations in a binuclear iron(III) complex

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    The ultraviolet absorption spectrum of an isolated metal complex containing the bridging unit Fe(III)⋯O-Fe(III) shows several bands due to the simultaneous electronic excitation of the two Fe(III) centers. The band positions are in excellent agreement with calculated sums of one-center d-d transitions

    Magnetic Behavior and Infrared Spectra of Jarosite, Basic Iron Sulfate, and Their Chromate Analogs

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    The magnetic behavior and infrared spectroscopic features of KFe_3(SO_4)_2(OH)_6 (jarosite), (H_3O)Fe_3(SO_4)_2(OH)_6 (hydronium jarosite), KFe_3(CrO_4)_2(OH)_6, Fe(OH)SO_4 (basic iron sulfate) and Fe(OH)CrO_4 (basic iron chromate) are reported. Spectroscopic data are in accord with X-ray data which show that KFe_3(SO_4)_2(OH)_6, (H_3O)Fe_3(SO_4)_2(OH)_6, and KFe_3(CrO_4)_2(OH)_6 are isostructural with KAl_3(SO_4)_2(OH)_6 (akunite). All the species exhibit negative deviations from Curie-Weiss behavior over the temperature range 300-76°K. The compounds KFe_3(CrO_4)_2(OH)_6 and Fe(OH)CrO_4 undergo ferrimagnetic transitions at 73 and 71°K, respectively. Maxima occur in the susceptibilities of KFe_3(SO_4)_2(OH)_6 and (H_3O)Fe_3(SO_4)_2(OH)_6 at 45 and 50°K
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