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P-NITROPHENYL PHOSPHATASE ACTIVITY IN MICROSOMAL FRACTION OF TURTLE BLADDER MUCOSAL CELLS

BIOCHIMICA ET BIOPHYSICA ACTA 1970年第3期211卷 565-&页

作者： SHAMOO, YE SCOTT, WN HOGG, J BRODSKY, WA Institute for Medical Research and Studies and The Doctoral Program in Biochemistry of the City University of New York and Mount Sinai Medical and Graduate Schools of CUNY New York N.Y. U.S.A.

The microsomes of turtle bladder epithelium contain a K + -stimulatable, ouabain- and/or Na + -inhibitable p- nitrophenyl phosphatase with an absolute requirement for Mg 2+ . The optimal pH range was 7.2–7.3 in the imidazole-histidine buffer system used. Treating the data in terms of Michaelis-Menten kinetics, the apparent K m 's were as follows: for p- nitrophenyl phosphate, 0.6 mM; for Mg 2+ , 0.6 mM; and for K + , 1.0. Substrate inhibition was observed for p- nitrophenyl phosphate, Mg 2+ , and K + at concentrations exceeding 4.0, 4.0 and 10 mM, respectively. 0.1 mM ouabain, or 100 mM Na + , completely inhibited the p- nitrophenyl phosphatase activity, and each inhibitor reacted competitively with K + for enzymes sites ( K i for ouabain - 25 nM and K i for Na + = 3.0 mM ). The inhibitory action of N- ethylmaleimide was dependent upon the time of pre-incubation of the microsomes with N- ethylmaleimide . Related to the question of whether p- nitrophenyl phosphatase is the same as or distinct from ( Na + + K + )-ATPase , is the fact that p- nitrophenyl phosphatase activity is inhibited competitively in the presence of ATP.

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Freeze-Drying of 6-Pentyl-α-Pyrone Produced by Trichoderma harzianum IOC4042 in Solid State Fermentation

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Industrial Biotechnology 2019年第4期15卷 256-262页

作者： Da Penha, Manoela Pessanha Rocha-Leão, Maria Helena Miguez Da Leite, Selma Gomes Ferreira Graduate Program of Food Science Federal University of Rio de Janeiro Rio de Janeiro Brazil Biochemistry Engineering Departament Federal University of Rio de Janeiro Rio de Janeiro Brazil

The search for products containing natural ingredients has spurred researchers to develop biotechnological processes for the production of aroma compounds, such as solid state fermentation (SSF), in which industrial waste can be used as an inert support. The aim of this study was to obtain, through freeze-drying and Capsul® as wall material, powdered aroma compound 6-pentyl-α-pyrone (6-PP) produced by Trichoderma harzianum IOC 4042 by SSF using sugarcane bagasse as support. According to similar studies, day 7 showed the highest yields. About 86.3 ppm of 6-PP was obtained in the powder after freeze drying, corresponding to 31.2% bioaroma retention. By freeze-drying technique using Capsul® as wall material, it was possible to microencapsulate the aroma compound. © Copyright 2019, Mary Ann Liebert, Inc., publishers 2019.

关键词： Odors

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K+-STIMULATED PHOSPHATASE OF MICROSOMES FROM GASTRIC MUCOSA

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JOURNAL OF CELLULAR PHYSIOLOGY 1967年第3期69卷 293-+页

作者： FORTE, JG FORTE, GM SALTMAN, P Department of Physiology University of California Berkeley California The Graduate Program in Biochemistry University of Southern California Los Angeles California Research Career Development Awardee U.S. Public Health Service.

The light microsomal fraction was isolated from homogenates of rabbit and bullfrog gastric mucosa. On examination with the elec-tron microscope, the light microsomes appear as tubular membranous structures with morphology and dimensions similar to the elements of the smooth-surfaced endoplasmic reticulum seen in intact oxyntic cells. A K+-stimulated, Mg++-requiring p-nitrophenylphosphatase [PNPP] has been demonstrated in the gastric microsomes. Neither Na+ nor ouabain (10-6-10-3 [image]) altered the K+-stimulated phosphatase. SCN- was not very effective as an inhibitor of the gastric micro-somal phosphatase, in contrast to the effect of this anion on the ATPase activity;however, the gastric phosphatase as well as the ATPase are destroyed by phospholipase C, thus showing the lipoprotein nature of these enzymes. Kinetics of the K+ activation of the micro-somal phosphatase suggest that the K+-PNPP complex is the active substrate for the enzymic reaction. Rb+, NH4+ and Cs+ will substitute to some degree for K+ as an activator of the microsomal phosphatase. It is pointed out that K+ is an essential requirement for HC1 secretion in intact gastric mucosa and the replacement of K+ with Rb+, Cs+ and NH4+ is discussed. The K+-stimulated phosphatase presented in this paper may play a role in the H+ secretion process.

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Whitening Dentifrices Effect on Enamel with Orthodontic Braces after Simulated Brushing

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European Journal of Dentistry 2020年第1期14卷 13-18页

作者： Torres, Vivian Santos Lima, Max José Pimenta Valdrighi, Heloísa Cristina Campos, Elisângela De Jesus Santamaria, Milton Graduate Program of Orthodontics Hemínio Ometto Foundation-FHO Araras São Paulo Brazil Department of Biochemistry and Biophysics UFBA Salvador Bahia Brazil Graduate Program of Biomedical Sciences Hemínio Ometto Foundation-FHO Araras São Paulo Brazil

Objective This study aimed to evaluate in vitro the effects of whitening dentifrices on enamel color, the shear bond strength of orthodontic brackets and adhesive remnant index (ARI). Materials and Methods Eighty bovine teeth with brackets were randomly divided into four groups (n = 20): control group (GC)-water, test group 1 (GT1)-Colgate Total 12, test group 2 (GT2)-Curaprox Black Is White, and group test 3 (GT3)-Luminous White. All groups were submitted to brushing, simulating 12 months. The specimens were exposed to spectrophotometer color evaluation and to a shear strength test in a universal test machine using a 300 kN load with a crosshead speed of 0.5 mm/min. The ARI was evaluated with a stereoscopic magnifying glass. Statistical Analysis Nonparametric Kruskal-Wallis and Dunn's tests were used for the color analysis, and Friedman and Nemenyi tests were used to compare the times in the variable. To compare the shear force between the groups, the data were evaluated by one-way analysis of variance and Tukey's test, and ARI was analyzed using Fisher's exact test, always with a significance level of 5%. Results In the color analysis, GT3 presented the greatest progression in whitening effect. GT1 had greater shear strength than GT3 did (p ≤ 0.05). For ARI, the score 1 was predominant in the GC and GT1. The GT2 and GT3 groups had scores of 3. Conclusion The whitening dentifrices promoted significant color change over the 12-month brushing time and may have interfered in the resistance to shear bond strength and ARI. © 2020 Dental Investigation Society.

关键词： dentifrices orthodontic brackets shear strength tooth bleaching

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Cellular and Transcriptional Heterogeneity in the Intrahepatic Biliary Epithelium

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Gastro Hep Advances 2023年第1期2卷 108-120页

作者： Hrncir, Hannah R. Gracz, Adam D. Division of Digestive Diseases Department of Medicine Emory University Atlanta GA United States Graduate Program in Biochemistry Cell and Developmental Biology Emory University Atlanta GA United States Graduate Program in Genetics and Molecular Biology Emory University Atlanta GA United States

Epithelial tissues comprise heterogeneous cellular subpopulations, which often compartmentalize specialized functions such as absorption and secretion to distinct cell types. In the liver, hepatocytes and biliary epithelial cells (BECs;also called cholangiocytes) are the 2 major epithelial lineages and play distinct roles in (1) metabolism, protein synthesis, detoxification;and (2) bile transport and modification, respectively. Recent technological advances, including single-cell transcriptomic assays, have shed new light on well-established heterogeneity among hepatocytes, endothelial cells, and immune cells in the liver. However, a “ground truth” understanding of molecular heterogeneity in BECs has remained elusive, and the field currently lacks a set of consensus biomarkers for identifying BEC subpopulations. Here, we review long-standing definitions of BEC heterogeneity as well as emerging studies that aim to characterize BEC subpopulations using next-generation single-cell assays. Understanding cellular heterogeneity in the intrahepatic bile ducts holds promise for expanding our foundational mechanistic knowledge of BECs during homeostasis and disease. © 2023 The Authors

关键词： Cellular heterogeneity Cholangiocyte Intrahepatic bile ducts Liver Single cell biology

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Hepatitis B virus and micro RNAs:Complex interactions affecting hepatitis B virus replication and hepatitis B virusassociated diseases

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World Journal of Gastroenterology 2015年第24期21卷 7375-7399页

作者： Jason Lamontagne Laura F Steel Michael J Bouchard Microbiology and Immunology Graduate Program Graduate School of Biomedical Sciences and Professional Studies Drexel University College of MedicinePhiladelphia Department of Microbiology and Immunology Institute for Molecular Medicine and Infectious Disease Drexel University College of Medicine Philadelphia Department of Biochemistry Drexel University College of Medicine Philadelphia

Chronic infection with the hepatitis B virus(HBV) is the leading risk factor for the development of hepatocellular carcinoma(HCC). With nearly 750000 deaths yearly, hepatocellular carcinoma is the second highest cause of cancer-related death in the world. Unfortunately, the molecular mechanisms that contribute to the development of HBV-associated HCC remain incompletely understood. Recently, micro RNAs(mi RNAs), a family of small non-coding RNAs that play a role primarily in post-transcriptional gene regulation, have been recognized as important regulators of cellular homeostasis, and altered regulation of mi RNA expression has been suggested to play a significant role in virus-associated diseases and the development of many cancers. With this in mind, many groups have begun to investigate the relationship between mi RNAs and HBV replication and HBV-associated disease. Multiple findings suggest that some mi RNAs, such as mi R-122, and mi R-125 and mi R-199 family members, are playing a role in HBV replication and HBV-associated disease, including the development of HBV-associated HCC. In this review, we discuss the current state of our understanding of the relationship between HBV and mi RNAs, including how HBV affects cellular mi RNAs, how these mi RNAs impact HBV replication, and the relationship between HBV-mediated mi RNA regulation and HCC development. We also address the impact of challenges in studying HBV, such as the lack of an effective model system for infectivity and a reliance on transformed cell lines, on our understanding of the relationship between HBV and mi RNAs, and proposepotential applications of mi RNA-related techniques that could enhance our understanding of the role mi RNAs play in HBV replication and HBV-associated disease, ultimately leading to new therapeutic options and improved patient outcomes.

关键词： Hepatitis B virus MicroRNA Hepatocellularcarcinoma Hepatitis B virus replication

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Vitamin D supplementation: Biochemical and inflammatory effects in non-pathological Wistar rats

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Toxicology Reports 2025年 14卷 101901页

作者： Muller de Moura Sarmento, Silvia Gomes Schmitt, Elizandra Smolski dos Santos, Laura Erminda Schreiner, Gênifer Tamborena Malheiros, Rafael Klock, Clóvis Casanova Petry, Charline Gonçalves, Itamar Luís Manfredini, Vanusa Pós-Graduate Program in Biochemistry Federal University of Pampa BR 472 Km 585 RS Uruguaiana Brazil Programa de Pós-graduação Multicêntrico em Ciências Fisiológicas Universidade Federal do Pampa Campus Uruguaiana Rio Grande do Sul Brazil Grupo Infolaudo e Medicina Diagnóstica Rio Grande do Sul Erechim Brazil Universidade Regional Integrada Alto-Uruguai e das Missões Sete de Setembro Avenue 1621 Rio Grande do Sul Erechim Brazil

Vitamin D3 (VD3) is shown to be a biochemical and physiological modulator of the body. Debates about route of administration, prescribed dosage and serum levels have arisen, and thus the interaction of VD3 with the bo... 详细信息

Vitamin D₃ (VD₃) is shown to be a biochemical and physiological modulator of the body. Debates about route of administration, prescribed dosage and serum levels have arisen, and thus the interaction of VD₃ with the body in overdose. Using an experimental model of Wistar rats of both sexes, rats were subdivided into 5 groups, which represents a control group, and 4 groups with VD₃ treatments (2.500, 7.000, 14.000 and 21.000 IU/kg/week) for one month. Thereafter biochemical, hormonal, inflammatory and histological analyses were performed. Regarding the biochemical findings, there was an increase in the levels of the AST in comparison of the control group with the treatments with higher doses (14.000 IU and 21.000 IU). Furthermore, changes in the inflammatory cytokine profile were identified at doses of 14,000 IU and 21,000 IU, with an increase in inflammatory cytokines (IL-1β, IL-6, IL-8 and TNF-α) and a decrease in the anti-inflammatory IL-10. Histological evaluation of the liver tissue also revealed changes at the highest doses. Finally, in the evaluation of a murine physiological model, it showed that the supplementation of VD₃ in overdoses there was an inflammatory exacerbation in the body, suggesting that the VD₃ supplementation should be administered with caution, and takes into account physiological factors of the individual. © 2025 The Authors

关键词： Cholecalciferol Inflammatory cytokines Toxicity

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EPITHELIAL-MESENCHYMAL INTERACTIONS DURING ODONTOGENESIS .1. ISOLATION OF SEVERAL INTERCELLULAR MATRIX LOW MOLECULAR WEIGHT METHYLATED RNAS

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DEVELOPMENTAL BIOLOGY 1970年第2期23卷 276-&页

作者： SLAVKIN, HC FLORES, P BRINGAS, P BAVETTA, LA Department of Biochemistry School of Dentistry University of Southern California Los Angeles CA 90007 United States the Graduate Program in Cellular and Molecular Biology University of Southern California Los Angeles CA 90007 United States

The present results and those previously reported (Slavkin et al. , 1969a) show that embryonic tooth primordia synthesize in organ culture four discrete methylated RNA species (7 S, 5 S, 4 S, and 2 S) isolated from the intercellular matrix interposed between epithelia and mesenchyme. These RNA species were first separated by gel exclusion chromatography and subsequently resolved with polyacrylamide gel disc electrophoresis. Resolution required employment of a variety of nucleic acid precursors, labeled methyl-methionine, liquid scintillation spectrometry, and autoradiography. The labeled precursors are initially incorporated into both epithelial and mesenchymal cells, primarily in the germinative or cervical region of the tooth primordia. Subsequently, small amounts of RNase labile material(s) are observed over the intercellular matrix; presumably transferred from both cell types. Tritiated thymidine is not found as a component of the intercellular matrix; deoxyribose is not found in the isolated matrices. Various labels cannot be incorporated into the intercellular matrix in the absence of associated cell populations. The kinetics of labeling within the components, both cell populations and matrix, have been investigated using autoradiography (Slavkin et al. , 1969a). On the basis of grain counts, only 2% of the total grain density incorporated within this epithelial-mesenchymal system is transferred into the intercellular matrix; Dactinomycin inhibits this process. This specific intercellular matrix has recently been shown to enhance homotypic cellular differentiation in vitro (Slavkin et al. , 1969b). Ultrastructural findings indicate the presence of membrane-bound, electron dense material (500–3000 Å diameter) within the matrix prior to phenol extraction; this material is not present in phenol-extracted matrices. Whether the extracted intercellular RNAs are to be found within the membrane-bound material observed within the matrix in situ (Slavkin et al. , 1969b,

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Four Previously Identified Petunia inflata S-Locus F-Box Genes Are Involved in Pollen Specificity in Se If-I ncom pati bi I ity

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Molecular Plant 2014年第3期7卷 567-569页

作者： Justin S. Williams Christopher A. Natale NingWang Shu Li Tarah R. Brubaker Penglin Sun Teh-hui Kao Department of Biochemistry and Molecular Biology The Pennsylvania State University University Park PA 16802 USA Intercollege Graduate Degree Program in Plant Biology The Pennsylvania State University University Park PA 16802 USA

Dear Editor, Petunia possesses self-incompatibility （SI）, by which pis- tils reject self-pollen but accept non-self pollen for fertili- zation （de Nettancourt, 2001; Iwano and Takayama, 2012）. Genes that regulate self-/non-self-recognition between pol- len and pistil are located at the highly polymorphic S-locus. An S-haplotype contains the pistil-specific S-RNase gene that regulates pistil specificity （Lee et al., 1994）. The first S-locus F-box （SLIO gene was identified in Antirrhinum hispanicum by Lai et al. （2002）, and subsequently Sijacic et al.

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Lipid Droplet Contacts With Autophagosomes, Lysosomes, and Other Degradative Vesicles

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Contact 2020年 3卷 1-13页

作者： Drizyte-Miller, Kristina Schott, Micah B. McNiven, Mark A. Biochemistry and Molecular Biology Program Mayo Clinic Graduate School of Biomedical Sciences Mayo Clinic Rochester MN United States Division of Gastroenterology and Hepatology Department of Biochemistry and Molecular Biology Mayo Clinic Rochester MN United States

Lipid droplets (LDs) are dynamic fat-storage organelles that interact readily with numerous cellular structures and organelles. A prominent LD contact site is with degradative vesicles such as autophagosomes, lysosomes, autolysosomes, and late endosomes. These contacts support lipid catabolism through the selective autophagy of LDs (i.e., lipophagy) or the recruitment of cytosolic lipases to the LD surface (i.e., lipolysis). However, LD–autophagosome contacts serve additional functions beyond lipid catabolism, including the supply of lipids for autophagosome biogenesis. In this review, we discuss the molecular mediators of LD contacts with autophagosomes and other degradative organelles as well as the diverse cellular functions of these contact sites in health and disease. © The Author(s) 2020.

关键词： autophagosome autophagy cell biology endosome lipid droplet lysosome

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