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Published: 10 December 2022
Last updated: 28 January 2023

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1

Peng, Qian-Long, Chuang-Ye Li, Yao-Wang Zhao, Xin-Yuan Sun, Hong Liu, and Jian-Ming Ouyang. "Protective Effect of Degraded Porphyra yezoensis Polysaccharides on the Oxidative Damage of Renal Epithelial Cells and on the Adhesion and Endocytosis of Nanocalcium Oxalate Crystals." Oxidative Medicine and Cellular Longevity 2021 (March 3, 2021): 1–15. http://dx.doi.org/10.1155/2021/6463281.

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The protective effects of Porphyra yezoensis polysaccharides (PYPs) with molecular weights of 576.2 (PYP1), 105.4 (PYP2), 22.47 (PYP3), and 3.89 kDa (PYP4) on the oxidative damage of human kidney proximal tubular epithelial (HK-2) cells and the differences in adherence and endocytosis of HK-2 cells to calcium oxalate monohydrate crystals before and after protection were investigated. Results showed that PYPs can effectively reduce the oxidative damage of oxalic acid to HK-2 cells. Under the preprotection of PYPs, cell viability increased, cell morphology improved, reactive oxygen species levels decreased, mitochondrial membrane potential increased, S phase cell arrest was inhibited, the cell apoptosis rate decreased, phosphatidylserine exposure reduced, the number of crystals adhered to the cell surface reduced, but the ability of cells to endocytose crystals enhanced. The lower the molecular weight, the better the protective effect of PYP. The results in this article indicated that PYPs can reduce the risk of kidney stone formation by protecting renal epithelial cells from oxidative damage and reducing calcium oxalate crystal adhesion, and PYP4 with the lowest molecular weight may be a potential drug for preventing kidney stone formation.
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2

Wagner, Karin, Jennifer Schilling, Stefan Fälker, M. Alexander Schmidt, and Gerhard Heusipp. "A Regulatory Network Controls Expression of the In Vivo-Expressed HreP Protease of Yersinia enterocolitica." Journal of Bacteriology 191, no. 5 (December 29, 2008): 1666–76. http://dx.doi.org/10.1128/jb.01517-08.

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ABSTRACT The human enteropathogen Yersinia enterocolitica survives and replicates in the lymphoid tissues of its host. Previous in vivo analyses of gene expression revealed that various chromosomal genes are expressed at this stage of infection, but not in vitro. One of these, termed hreP, encodes a protease that is necessary for full virulence of Y. enterocolitica. Using transposon mutagenesis, we identified three genes, pypA, pypB, and pypC, as positive regulators of hreP transcription. PypA is an inner membrane protein with no significant similarity to any known proteins; PypB is a ToxR-like transmembrane transcriptional regulator; and PypC is a cytoplasmic transcriptional regulator with an OmpR-like winged helix-turn-helix DNA binding motif. We show that all Pyp proteins are able to activate hreP independently of each other and that PypB and PypC interact directly with the hreP promoter region. Furthermore, pypB and pypC are autoregulated and regulate each other. Additional data indicate that transcription of hreP is repressed by the histone-like nucleoid-structuring protein H-NS in a temperature-dependent manner. Our data reveal a new regulatory network that might have implications for the controlled expression of further virulence-associated functions in Yersinia.
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ISOBE, Takanori, Toshihiro OHIGASHI, Hidenori KUWAKADO, and Masakatu MORII. "A Chosen-IV Key Recovery Attack on Py and Pypy." IEICE Transactions on Information and Systems E92-D, no. 1 (2009): 32–40. http://dx.doi.org/10.1587/transinf.e92.d.32.

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4

Ferreira, Duarte Nuno Gonçalves. "Rectangular Bin-Packing Problem: a computational evaluation of 4 heuristics algorithms." U.Porto Journal of Engineering 1, no. 1 (September 6, 2017): 35–49. http://dx.doi.org/10.24840/2183-6493_001.001_0005.

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The Rectangular Bin-packing Problem, also known as The Two-dimensional Bin-packing Problem (2DBPP), is a well-known combinatorial optimization problem which is the problem of orthogonally packing a given set of rectangles into a minimum number of two-dimensional rectangular bins. In this article we benchmark four heuristics: constructive, based on a First Fit Decreasing strategy, local search using a greedy packing First-Fit algorithm, Simulated Annealing with multiple cooling values and Genetic Algorithm. All implementations are written in Python, run using the Pypy environment and the new multiprocessing module. All implementations were tested using the Berkey and Wang and Martelo and Vigo Benchmark Instances.
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5

Ottilie, S., J. Chernoff, G. Hannig, C. S. Hoffman, and R. L. Erikson. "The fission yeast genes pyp1+ and pyp2+ encode protein tyrosine phosphatases that negatively regulate mitosis." Molecular and Cellular Biology 12, no. 12 (December 1992): 5571–80. http://dx.doi.org/10.1128/mcb.12.12.5571-5580.1992.

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We have used degenerate oligonucleotide probes based on sequences conserved among known protein tyrosine phosphatases (PTPases) to identify two Schizosaccharomyces pombe genes encoding PTPases. We previously described the cloning of pyp1+ (S. Ottilie, J. Chernoff, G. Hannig, C. S. Hoffman, and R. L. Erikson, Proc. Natl. Acad. Sci. USA 88:3455-3459, 1991), and here we describe a second gene, called pyp2+. The C terminus of each protein contains sequences conserved in the apparent catalytic domains of all known PTPases. Disruption of pyp2+ results in viable cells, as was the case for pyp1+, whereas disruption of pyp2+ and pyp1+ results in synthetic lethality. Overexpression of either pyp1+ or pyp2+ in wild-type strains leads to a delay in mitosis but is suppressed by a wee1-50 mutation at 35 degrees C or a cdc2-1w mutation. A pyp1 disruption suppresses the temperature-sensitive lethality of a cdc25-22 mutation. Our data suggest that pyp1+ and pyp2+ act as negative regulators of mitosis upstream of the wee1+/mik1+ pathway.
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Ottilie, S., J. Chernoff, G. Hannig, C. S. Hoffman, and R. L. Erikson. "The fission yeast genes pyp1+ and pyp2+ encode protein tyrosine phosphatases that negatively regulate mitosis." Molecular and Cellular Biology 12, no. 12 (December 1992): 5571–80. http://dx.doi.org/10.1128/mcb.12.12.5571.

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We have used degenerate oligonucleotide probes based on sequences conserved among known protein tyrosine phosphatases (PTPases) to identify two Schizosaccharomyces pombe genes encoding PTPases. We previously described the cloning of pyp1+ (S. Ottilie, J. Chernoff, G. Hannig, C. S. Hoffman, and R. L. Erikson, Proc. Natl. Acad. Sci. USA 88:3455-3459, 1991), and here we describe a second gene, called pyp2+. The C terminus of each protein contains sequences conserved in the apparent catalytic domains of all known PTPases. Disruption of pyp2+ results in viable cells, as was the case for pyp1+, whereas disruption of pyp2+ and pyp1+ results in synthetic lethality. Overexpression of either pyp1+ or pyp2+ in wild-type strains leads to a delay in mitosis but is suppressed by a wee1-50 mutation at 35 degrees C or a cdc2-1w mutation. A pyp1 disruption suppresses the temperature-sensitive lethality of a cdc25-22 mutation. Our data suggest that pyp1+ and pyp2+ act as negative regulators of mitosis upstream of the wee1+/mik1+ pathway.
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7

Li, Yangguang, and Zhen Ming Jiang. "Assessing and optimizing the performance impact of the just-in-time configuration parameters - a case study on PyPy." Empirical Software Engineering 24, no. 4 (March 8, 2019): 2323–63. http://dx.doi.org/10.1007/s10664-019-09691-z.

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8

Arabas, Sylwester, Dorota Jarecka, Anna Jaruga, and Maciej Fijałkowski. "Formula Translation in Blitz++, NumPy and Modern Fortran: A Case Study of the Language Choice Tradeoffs." Scientific Programming 22, no. 3 (2014): 201–22. http://dx.doi.org/10.1155/2014/870146.

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Three object-oriented implementations of a prototype solver of the advection equation are introduced. The presented programs are based on Blitz++ (C++), NumPy (Python) and Fortran's built-in array containers. The solvers constitute implementations of the Multidimensional Positive-Definite Advective Transport Algorithm (MPDATA). The introduced codes serve as examples for how the application of object-oriented programming (OOP) techniques and new language constructs from C++11 and Fortran 2008 allow to reproduce the mathematical notation used in the literature within the program code. A discussion on the tradeoffs of the programming language choice is presented. The main angles of comparison are code brevity and syntax clarity (and hence maintainability and auditability) as well as performance. All performance tests are carried out using free and open-source compilers. In the case of Python, a significant performance gain is observed when switching from the standard interpreter (CPython) to the PyPy implementation of Python. Entire source code of all three implementations is embedded in the text and is licensed under the terms of the GNU GPL license.
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9

Zhereb, K. A. "Improving performance of Python code using rewriting rules technique." PROBLEMS IN PROGRAMMING, no. 2-3 (September 2020): 115–25. http://dx.doi.org/10.15407/pp2020.02-03.115.

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Python is a popular programming language used in many areas, but its performance is significantly lower than many compiled languages. We propose an approach to increasing performance of Python code by transforming fragments of code to more efficient languages such as Cython and C++. We use high-level algebraic models and rewriting rules technique for semi-automated code transformation. Performance-critical fragments of code are transformed into a low-level syntax model using Python parser. Then this low-level model is further transformed into a high-level algebraic model that is language-independent and easier to work with. The transformation is automated using rewriting rules implemented in Termware system. We also improve the constructed high-level model by deducing additional information such as data types and constraints. From this enhanced high-level model of code we generate equivalent fragments of code using code generators for Cython and C++ languages. Cython code is seamlessly integrated with Python code, and for C++ code we generate a small utility file in Cython that also integrates this code with Python. This way, the bulk of program code can stay in Python and benefit from its facilities, but performance-critical fragments of code are transformed into more efficient equivalents, improving the performance of resulting program. Comparison of execution times between initial version of Python code, different versions of transformed code and using automatic tools such as Cython compiler and PyPy demonstrates the benefits of our approach – we have achieved performance gains of over 50x compared to the initial version written in Python, and over 2x compared to the best automatic tool we have tested.
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10

Degols, G., K. Shiozaki, and P. Russell. "Activation and regulation of the Spc1 stress-activated protein kinase in Schizosaccharomyces pombe." Molecular and Cellular Biology 16, no. 6 (June 1996): 2870–77. http://dx.doi.org/10.1128/mcb.16.6.2870.

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Spc1, an osmotic-stress-stimulated mitogen-activated protein kinase (MAPK) homolog in the fission yeast Schizosaccharomyces pombe, is required for the induction of mitosis and survival in high-osmolarity conditions. Spc1, also known as Sty1, is activated by Wis1 MAPK kinase and inhibited by Pyp1 tyrosine phosphatase. Spc1 is most closely related to Saccharomyces cerevisiae Hog1 and mammalian p38 kinases. Whereas Hog1 is specifically responsive to osmotic stress, we report here that Spc1 is activated by multiple forms of stress, including high temperature and oxidative stress. In this regard Spc1 is more similar to mammalian p38. Activation of Spc1 is crucial for survival of various forms of stress. Spc1 regulates expression of genes encoding stress-related proteins such as glycerol-3-phosphate dehydrogenase (gpd1+) and trehalose-6-phosphate synthase (tps1+). Spc1 also promotes expression of pyp2+, which encodes a tyrosine phosphatase postulated as a negative regulator of Spc1. This proposal is supported by the finding that Spc1 associates with Pyp2 in vivo and that the amount of Spc1 tyrosine phosphorylation is lower in a Pyp2-overproducing strain than in the wild type. Moreover, the level of stress-stimulated gpd1+ expression is higher in delta pyp2 mutants than in the wild type. These findings demonstrate that Spc1 promotes expression of genes involved in stress survival and that of regulation may be commonly employed to modulate MAPK signal transduction pathways in eukaryotic species.
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11

Shiozaki, Kazuhiro, Mitsue Shiozaki, and Paul Russell. "Heat Stress Activates Fission Yeast Spc1/StyI MAPK by a MEKK-Independent Mechanism." Molecular Biology of the Cell 9, no. 6 (June 1998): 1339–49. http://dx.doi.org/10.1091/mbc.9.6.1339.

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Fission yeast Spc1/StyI MAPK is activated by many environmental insults including high osmolarity, oxidative stress, and heat shock. Spc1/StyI is activated by Wis1, a MAPK kinase (MEK), which is itself activated by Wik1/Wak1/Wis4, a MEK kinase (MEKK). Spc1/StyI is inactivated by the tyrosine phosphatases Pyp1 and Pyp2. Inhibition of Pyp1 was recently reported to play a crucial role in the oxidative stress and heat shock responses. These conclusions were based on three findings: 1) osmotic, oxidative, and heat stresses activate Spc1/StyI in wis4 cells; 2) oxidative stress and heat shock activate Spc1/StyI in cells that express Wis1AA, in which MEKK consensus phosphorylation sites were replaced with alanine; and 3) Spc1/StyI is maximally activated in Δpyp1 cells. Contrary to these findings, we report: 1) Spc1/StyI activation by osmotic stress is greatly reduced in wis4 cells; 2)wis1-AA and Δwis1 cells have identical phenotypes; and 3) all forms of stress activate Spc1/StyI inΔpyp1 cells. We also report that heat shock, but not osmotic or oxidative stress, activate Spc1 in wis1-DDcells, which express Wis1 protein that has the MEKK consensus phosphorylation sites replaced with aspartic acid. Thus osmotic and oxidative stress activate Spc1/StyI by a MEKK-dependent process, whereas heat shock activates Spc1/StyI by a novel mechanism that does not require MEKK activation or Pyp1 inhibition.
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12

Hannig, G., S. Ottilie, and R. L. Erikson. "Negative regulation of mitosis in fission yeast by catalytically inactive pyp1 and pyp2 mutants." Proceedings of the National Academy of Sciences 91, no. 21 (October 11, 1994): 10084–88. http://dx.doi.org/10.1073/pnas.91.21.10084.

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13

Mano, Eriko, Hironari Kamikubo, Yasushi Imamoto, and Mikio Kataoka. "Comparison of the Photochemical Reaction of Photoactive Yellow Protein in Crystal with Reaction in Solution1." Spectroscopy 17, no. 2-3 (2003): 345–53. http://dx.doi.org/10.1155/2003/123586.

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Photoactive yellow protein (PYP) is a photoreceptor protein for the negative phototaxis ofEctothiorhodospira halophila. The crystal structures of several photo‒intermediates have been revealed by X-ray crystallography. In the crystal structure of the active intermediate, PYPM, no significant structural changes were observed except for the vicinity of the chromophore. On the contrary, spectroscopic studies with solution condition demonstrated that global structural changes occur during the photo‒cycle. In order to reveal the origin of the discrepancies, we measured the reaction kinetics upon illumination under crystal condition and to compare them with those observed under solution condition. The reactive portion decreases with the increase of crystallinity. The rate constant of PYPMdecay also decreases with the increase of crystallinity. These results suggest two possibilities: (1) PYP in crystal does not react by the illumination; (2) the photoreaction rate is highly accelerated in crystal. Consequently, the photoreaction in crystal is considered to be highly influenced by the force constraint from crystalline lattice.
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Yamamoto, H., N. Hamada, M. Kumauchi, J. Sasaki, T. Sumi, N. Ueyama, and F. Tokunaga. "A residual motion analysis of PYP from PYPM to PYPdark in the photocycle system." Seibutsu Butsuri 41, supplement (2001): S6. http://dx.doi.org/10.2142/biophys.41.s6_3.

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15

Millar, J. B., V. Buck, and M. G. Wilkinson. "Pyp1 and Pyp2 PTPases dephosphorylate an osmosensing MAP kinase controlling cell size at division in fission yeast." Genes & Development 9, no. 17 (September 1, 1995): 2117–30. http://dx.doi.org/10.1101/gad.9.17.2117.

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16

Gaits, Frédérique, and Paul Russell. "Active Nucleocytoplasmic Shuttling Required for Function and Regulation of Stress-Activated Kinase Spc1/StyI in Fission Yeast." Molecular Biology of the Cell 10, no. 5 (May 1999): 1395–407. http://dx.doi.org/10.1091/mbc.10.5.1395.

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Transcriptional induction of many stress-response genes is dependent on stress-induced nuclear accumulation of stress-activated protein kinases (SAPKs). In the fission yeastSchizosaccharomyces pombe, nuclear accumulation of the SAPK Spc1 (also known as StyI) requires activating phosphorylation catalyzed by the SAPK kinase Wis1; however, it is unknown whether the localization of Spc1 is regulated by nuclear transport factors. Herein are reported studies that show that Spc1 localization is regulated by active transport mechanisms during osmotic stress. Nuclear import of Spc1 requires Pim1, a homologue of the guanine nucleotide exchange factor RCC1 that is essential for nucleocytoplasmic shuttling of proteins. Nuclear export of Spc1 is regulated by the export factor Crm1. An Spc1–Crm1 complex forms as Spc1 is exported from the nucleus. Wis1 and the tyrosine phosphatases Pyp1 and Pyp2 that inactivate Spc1 are excluded from the nucleus by a Crm1-independent mechanism; hence the nuclear import of Spc1 leads to transient isolation from its regulatory proteins. Thus, active nucleocytoplasmic shuttling is required for both the function and regulation of Spc1 during the osmotic shock response.
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Setiawan, Ely, and Agustino Zulys. "STUDI TEORITIS STRUKTUR DAN SPEKTRUM ELEKTRONIK KOMPLEKS [Ln(pytpy)(NO3)3] SECARA KOMPUTASI METODE SPARKLE/RM1." Molekul 10, no. 1 (May 1, 2015): 19. http://dx.doi.org/10.20884/1.jm.2015.10.1.168.

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Telah dilakukan penelitian tentang studi teoritis struktur dan spektrum elektronik kompleks [Ln(pytpy)(NO3)3] (Ln=Eu, Tb, pytpy=4’-(2-pyrrolyl)-2,2’:6’,2”-terpyridine) menggunakan metode komputasi semiempiris Sparkle/RM1. Metode Sparkle/RM1 ini dapat digunakan untuk memperoleh struktur geometri paling stabil dan parameter struktur dalam keadaan gas sebagai simulasi metode eksperimen yang mungkin terlalu mahal. Perhitungan spektrum elektronik dilakukan dengan ZINDO/S, dengan mengganti sparkle dengan titik muatan +3 pada koordinat yang dihasilkan melalui Sparkle/RM1. Hasil penelitian menunjukkan bahwa ion lantanida pada kompleks [Ln(pytpy)(NO3)3] memiliki bilangan koordinasi 9, yang berikatan dengan satu ligan tridentat pytpy dan tiga gugus nitrat sebagai ligan bidentat. Panjang ikatan rata-rata ion lantanida dengan atom N pada ligan pytpy adalah 2,541 Å dan 5,14 Å untuk Eu3+ dan Tb3+. Studi teoritis spektroskopi menunjukkan bahwa metode Sparkle/RM1 cukup akurat dalam memprediksi spektrum IR ligan pytpy, kompleks [Eu(pytpy)(NO3)3] maupun [Tb(pytpy)(NO3)3]. Spektrum UV-Vis kompleks [Eu(pytpy)(NO3)3] dan [Tb(pytpy)(NO3)3] memiliki intensitas serapan yang lebih kuat dan absorbansi yang lebih besar dari spektrum UV-Vis ligan pytpy.
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18

Dal Santo, P., B. Blanchard, and C. S. Hoffman. "The Schizosaccharomyces pombe pyp1 protein tyrosine phosphatase negatively regulates nutrient monitoring pathways." Journal of Cell Science 109, no. 7 (July 1, 1996): 1919–25. http://dx.doi.org/10.1242/jcs.109.7.1919.

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The Schizosaccharomyces pombe pyp1+ gene, encoding a protein tyrosine phosphatase (pyp1), was isolated as a high copy number suppressor of a mutation that results in reduced cAMP-dependent protein kinase (PKA) activity. Overexpression of pyp1+ inhibits both transcription of the fbp1 gene, which is negatively regulated by a glucose-induced activation of PKA, and sexual development, which is negatively regulated by PKA through a nitrogen- and glucose-monitoring mechanism. Overexpression of a catalytically inactive form of pyp1 has little effect on either process. Previous studies suggest that overexpression of pyp1+ results in a mitotic delay by positively regulating wee1 activity. We show that pyp1 repression of fbp1 transcription is independent of wee1. The direct role of the pyp1 protein is to dephosphorylate and inactivate the sty1/spc1 mitogen-activated protein kinase (MAPK) that is activated by the wis1 MAPK kinase. As overexpression of pyp1+ has no further effect upon the mitotic delay observed in a wis1 deletion strain, the role of pyp1 appears to be restricted to negative regulation of the sty1/spc1 MAPK. This study indicates that pyp1 negatively regulates fbp1 transcription, sexual development and mitosis by inactivation of the sty1/spc1 MAPK, but that bifurcations downstream of the MAPK separate these processes as seen by the differential role for the wee1 gene.
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19

Barbosa, Andrezza M., José F. Sarmento-Neto, José E. R. Menezes Filho, Itamar C. G. Jesus, Diego S. Souza, Valério M. N. Vasconcelos, Fagner D. L. Gomes, et al. "Redox-Active Drug, MnTE-2-PyP5+, Prevents and Treats Cardiac Arrhythmias Preserving Heart Contractile Function." Oxidative Medicine and Cellular Longevity 2020 (March 21, 2020): 1–15. http://dx.doi.org/10.1155/2020/4850697.

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Background. Cardiomyopathies remain among the leading causes of death worldwide, despite all efforts and important advances in the development of cardiovascular therapeutics, demonstrating the need for new solutions. Herein, we describe the effects of the redox-active therapeutic Mn(III) meso-tetrakis(N-ethylpyridinium-2-yl)porphyrin, AEOL10113, BMX-010 (MnTE-2-PyP5+), on rat heart as an entry to new strategies to circumvent cardiomyopathies. Methods. Wistar rats weighing 250-300 g were used in both in vitro and in vivo experiments, to analyze intracellular Ca2+ dynamics, L-type Ca2+ currents, Ca2+ spark frequency, intracellular reactive oxygen species (ROS) levels, and cardiomyocyte and cardiac contractility, in control and MnTE-2-PyP5+-treated cells, hearts, or animals. Cells and hearts were treated with 20 μM MnTE-2-PyP5+ and animals with 1 mg/kg, i.p. daily. Additionally, we performed electrocardiographic and echocardiographic analysis. Results. Using isolated rat cardiomyocytes, we observed that MnTE-2-PyP5+ reduced intracellular Ca2+ transient amplitude, without altering cell contractility. Whereas MnTE-2-PyP5+ did not alter basal ROS levels, it was efficient in modulating cardiomyocyte redox state under stress conditions; MnTE-2-PyP5+ reduced Ca2+ spark frequency and increased sarcoplasmic reticulum (SR) Ca2+ load. Accordingly, analysis of isolated perfused rat hearts showed that MnTE-2-PyP5+ preserves cardiac function, increases SR Ca2+ load, and reduces arrhythmia index, indicating an antiarrhythmic effect. In vivo experiments showed that MnTE-2-PyP5+ treatment increased Ca2+ transient, preserved cardiac ejection fraction, and reduced arrhythmia index and duration. MnTE-2-PyP5+ was effective both to prevent and to treat cardiac arrhythmias. Conclusion. MnTE-2-PyP5+ prevents and treats cardiac arrhythmias in rats. In contrast to most antiarrhythmic drugs, MnTE-2-PyP5+ preserves cardiac contractile function, arising, thus, as a prospective therapeutic for improvement of cardiac arrhythmia treatment.
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Takefuji, Yoshiyasu. "Python Programming in PyPI for Translational Medicine." International Journal of Translational Medicine 1, no. 3 (November 24, 2021): 323–31. http://dx.doi.org/10.3390/ijtm1030019.

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This is the world’s first tutorial article on Python Packaging for beginners and practitioners for translational medicine or medicine in general. This tutorial will allow researchers to demonstrate and showcase their tools on PyPI packages around the world. Nowadays, for translational medicine, researchers need to deal with big data. This paper describes how to build an executable Python Package Index (PyPI) code and package. PyPI is a repository of software for the Python programming language with 5,019,737 files and 544,359 users (programmers) as of 19 October 2021. First, programmers must understand how to scrape a dataset over the Internet; second, they must read the dataset file in csv format; third, build a program to compute the target values; fourth, convert the Python program to the PyPI package.; and fifth, upload the PyPI package. This paper depicts a covidlag executable package as an example for calculating the accurate case fatality rate (CFR) and the lag time from infection to death. You can install the covidlag by pip terminal command and test it. This paper also introduces deathdaily and scorecovid packages on PyPI Stats, which can inform how many users have downloaded the specified PyPI package. The usefulness and applicability of a developed tool can be verified by PyPI Stats with the number of downloaded users.
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Núñez, Andrés, Alejandro Franco, Marisa Madrid, Teresa Soto, Jero Vicente, Mariano Gacto, and José Cansado. "Role for RACK1 Orthologue Cpc2 in the Modulation of Stress Response in Fission Yeast." Molecular Biology of the Cell 20, no. 18 (September 15, 2009): 3996–4009. http://dx.doi.org/10.1091/mbc.e09-05-0388.

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The receptor of activated C kinase (RACK1) is a protein highly conserved among eukaryotes. In mammalian cells, RACK1 functions as an adaptor to favor protein kinase C (PKC)-mediated phosphorylation and subsequent activation of c-Jun NH2-terminal kinase mitogen-activated protein kinase. Cpc2, the RACK1 orthologue in the fission yeast Schizosaccharomyces pombe, is involved in the control of G2/M transition and interacts with Pck2, a PKC-type protein member of the cell integrity Pmk1 mitogen-activated protein kinase (MAPK) pathway. Both RACK1 and Cpc2 are structural components of the 40S ribosomal subunit, and recent data suggest that they might be involved in the control of translation. In this work, we present data supporting that Cpc2 negatively regulates the cell integrity transduction pathway by favoring translation of the tyrosine-phosphatases Pyp1 and Pyp2 that deactivate Pmk1. In addition, Cpc2 positively regulates the synthesis of the stress-responsive transcription factor Atf1 and the cytoplasmic catalase, a detoxificant enzyme induced by treatment with hydrogen peroxide. These results provide for the first time strong evidence that the RACK1-type Cpc2 protein controls from the ribosome the extent of the activation of MAPK cascades, the cellular defense against oxidative stress, and the progression of the cell cycle by regulating positively the translation of specific gene products involved in key biological processes.
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Yang, Xiao, Hao-Long Zhou, Chun-Ting He, Zong-Wen Mo, Jia-Wen Ye, Xiao-Ming Chen, and Jie-Peng Zhang. "Flexibility of Metal-Organic Framework Tunable by Crystal Size at the Micrometer to Submillimeter Scale for Efficient Xylene Isomer Separation." Research 2019 (October 17, 2019): 1–9. http://dx.doi.org/10.34133/2019/9463719.

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Understanding, controlling, and utilizing the flexibility of adsorbents are of great importance and difficulty. Analogous with conventional solid materials, downsizing to the nanoscale is emerging as a possible strategy for controlling the flexibility of porous coordination polymers (or metal-organic frameworks). We report a unique flexibility controllable by crystal size at the micrometer to submillimeter scale. Template removal transforms [Cu2(pypz)2]·0.5p-xylene (MAF-36, Hpypz = 4-(1H-pyrazol-4-yl)pyridine) with one-dimensional channels to α-[Cu2(pypz)2] with discrete small cavities, and further heating gives a nonporous isomer β-[Cu2(pypz)2]. Both isomers can adsorb p-xylene to give [Cu2(pypz)2]·0.5p-xylene, meaning the coexistence of guest-driven flexibility and shape-memory behavior. The phase transition temperature from α-[Cu2(pypz)2] to β-[Cu2(pypz)2] decreased from ~270°C to ~150°C by increasing the crystal size from the micrometer to the submillimeter scale, ca. 2-3 orders larger than those of other size-dependent behaviors. Single-crystal X-ray diffraction showed coordination bond reconstitution and chirality inversion mechanisms for the phase transition, which provides a sufficiently high energy barrier to stabilize the metastable phase without the need of downsizing to the nanoscale. By virtue of the crystalline molecular imprinting and gate-opening effects, α-[Cu2(pypz)2] and β-[Cu2(pypz)2] show unprecedentedly high p-xylene selectivities of 16 and 51, respectively, as well as ultrafast adsorption kinetics (<2 minutes), for xylene isomers.
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23

Yilmaz, Fatih, Veysel T. Yilmaz, Haydar Karakaya, and Orhan Büyükgüngör. "5,5-Diethylbarbiturate Complexes of Silver with 2,2’-Bipyridine and 3-(2-Pyridyl)propanol: Syntheses, Crystal Structures, Spectroscopic, Thermal and Antimicrobial Activity Studies August 28, 2007." Zeitschrift für Naturforschung B 63, no. 2 (February 1, 2008): 134–38. http://dx.doi.org/10.1515/znb-2008-0204.

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Two silver 5,5-diethylbarbiturate (barb) complexes with 2,2'-bipyridine (bpy) and 3-(2-pyridyl) propanol (pypr), [Ag(barb)(bpy)] (1) and [Ag(barb)(pypr)] (2), have been prepared and characterized by elemental analysis, IR spectroscopy, thermal analysis, and single crystal X-ray diffraction. Both complexes crystallize in the triclinic space group P1 with Z = 2. The barb ligand in 1 is N-coordinated and the bpy ligand acts as a bichelating ligand leading to an AgN3 tricoordination. Crystals of 1 feature a three-dimensional network based on N-H···O hydrogen bonding, π(bpy)···π(bpy), C-H···π(bpy) and π(bpy)-Ag interactions. In 2, the pypr and barb ligands behave as monodentate ligands through their N atoms, forming a distorted linear AgN2 coordination. Molecules of 2 are doubly bridged by N-H···O hydrogen bonds and further connected via O-H···O hydrogen bonds and aromatic π(pypr)···π(pypr) stacking interactions into a supramolecular network. Both complexes exhibit similar thermal decomposition behavior in air. The first stage corresponds to removal of the co-ligands such as bpy or pypr while the degradation of the barb moiety occurs at higher temperatures to give Ag2O. Like the barb, bpy and pypr ligands, 2 does not show any significant antimicrobial activity, but 1 is active against bacteria and fungi
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24

Yoshinaga, K., T. Mochizuki, N. Yanaihara, K. Oshima, M. Izukura, M. Kogire, S. Sumi, et al. "Structural requirements of peptide YY for biological activity at enteric sites." American Journal of Physiology-Gastrointestinal and Liver Physiology 263, no. 5 (November 1, 1992): G695—G701. http://dx.doi.org/10.1152/ajpgi.1992.263.5.g695.

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Peptide YY (PYY) is a colonic hormone consisting of 36 amino acids that is a potent inhibitor of pancreatic exocrine, gastric acid, and insulin secretion. The objective of the present experiments was to characterize the structural requirements of PYY for inhibition of pancreatic exocrine, gastric acid, and insulin secretion, using conscious dogs prepared with gastric and pancreatic fistulas. Intravenous administration of PYY-(1-36), PYY-(3-36), or PYY-(4-36) (400 pmol.kg-1 x h-1) inhibited cholecystokinin-8-stimulated (25 pmol.kg-1 x h-1) pancreatic exocrine secretion (P < 0.05); however, PYY-(1-10), PYY-(1-20), PYY-(6-36), PYY-(10-36), PYY-(13-36), PYY-(24-36), and PYY-(27-36) did not inhibit pancreatic exocrine secretion. Intravenous administration of PYY-(1-36), PYY-(3-36), or PYY-(4-36) (200, 400, 800 pmol.kg-1 x h-1) inhibited pentagastrin (0.5 microgram.kg-1 x h-1)-stimulated gastric acid secretion (P < 0.05), as well as 2-deoxy-D-glucose-stimulated insulin release (75 mg/kg) in a dose-related manner. PYY-(6-36), PYY-(13-36), and [Leu31, Pro34] neuropeptide Y did not inhibit either gastric acid secretion or insulin release. In the gastric acid and insulin secretion bioassays, PYY-(1-36) was significantly more potent than PYY-(3-36) and PYY-(4-36); however, in the pancreatic exocrine secretion bioassay, the inhibitory effects of PYY-(3-36) and PYY-(1-36) did not differ significantly. PYY-(4-36) was less potent than PYY-(1-36) on pancreatic exocrine secretion.(ABSTRACT TRUNCATED AT 250 WORDS)
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25

Lafferty, Ryan A., Victor A. Gault, Peter R. Flatt, and Nigel Irwin. "Effects of 2 Novel PYY(1-36) Analogues, (P3L31P34)PYY(1-36) and PYY(1-36)(Lys12PAL), on Pancreatic Beta-Cell Function, Growth, and Survival." Clinical Medicine Insights: Endocrinology and Diabetes 12 (January 2019): 117955141985562. http://dx.doi.org/10.1177/1179551419855626.

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Recent studies have identified a beneficial role for peptide tyrosine tyrosine (PYY) on pancreatic beta-cell function and survival. These effects are linked to the activation of neuropeptide Y1 receptors (NPYR1s) by PYY(1-36). However, PYY(1-36) is subject to rapid degradation by dipeptidyl peptidase-4 (DPP-4), resulting is the loss of NPYR1 activity. Therefore, the aim of this study was to develop 2 enzymatically stable PYY(1-36) analogues, namely, (P3L31P34)PYY(1-36) and PYY(1-36)(Lys12PAL), with further structural modifications to enhance NPYR1 specificity. As expected, (P3L31P34)PYY(1-36) was fully resistant to DPP-4-mediated degradation in vitro, whereas PYY(1-36) and PYY(1-36)(Lys12PAL) were both liable to DPP-4 breakdown. PYY(1-36) and (P3L31P34)PYY(1-36) induced significant reductions in glucose-stimulated insulin secretion (GSIS) from BRIN BD11 cells, but only PYY(1-36) diminished alanine-stimulated insulin secretion. In contrast, PYY(1-36)(Lys12PAL) had no impact on GSIS or alanine-induced insulin release. All 3 PYY peptides significantly enhanced proliferation in BRIN BD11 and 1.1B4 beta-cell lines, albeit only at the highest concentration examined, 10-6 M, for (P3L31P34)PYY(1-36) and PYY(1-36)(Lys12PAL) in BRIN BD11 cells. Regarding the protection of beta-cells against cytokine-induced apoptosis, PYY(1-36) induced clear protective effects. Both (P3L31P34)PYY(1-36) and PYY(1-36)(Lys12PAL) offered some protection against apoptosis in BRIN BD11 cells, but were significantly less efficacious than PYY(1-36). Similarly, in 1.1B4 cells, both PYY analogues (10-6 M) protected against cytokine-induced apoptosis, but (P3L31P34)PYY(1-36) was significantly less effective than PYY(1-36). All 3 PYY peptides had no impact on refeeding in overnight fasted mice. These data underline the beta-cell benefits of PYY(1-36) and highlight the challenges of synthesising stable, bioactive, NPYR1-specific, PYY(1-36) analogues.
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Batinic-Haberle, Ines, Artak Tovmasyan, Zhiqing Huang, Weina Duan, Li Du, Sharareh Siamakpour-Reihani, Zhipeng Cao, Huaxin Sheng, Ivan Spasojevic, and Angeles Alvarez Secord. "H2O2-Driven Anticancer Activity of Mn Porphyrins and the Underlying Molecular Pathways." Oxidative Medicine and Cellular Longevity 2021 (March 15, 2021): 1–23. http://dx.doi.org/10.1155/2021/6653790.

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Mn(III) ortho-N-alkyl- and N-alkoxyalkyl porphyrins (MnPs) were initially developed as superoxide dismutase (SOD) mimics. These compounds were later shown to react with numerous reactive species (such as ONOO-, H2O2, H2S, CO3•-, ascorbate, and GSH). Moreover, the ability of MnPs to oxidatively modify activities of numerous proteins has emerged as their major mechanism of action both in normal and in cancer cells. Among those proteins are transcription factors (NF-κB and Nrf2), mitogen-activated protein kinases, MAPKs, antiapoptotic bcl-2, and endogenous antioxidative defenses. The lead Mn porphyrins, namely, MnTE-2-PyP5+ (BMX-010, AEOL10113), MnTnBuOE-2-PyP5+ (BMX-001), and MnTnHex-2-PyP5+, were tested in numerous injuries of normal tissue and cellular and animal cancer models. The wealth of the data led to the progression of MnTnBuOE-2-PyP5+ into four Phase II clinical trials on glioma, head and neck cancer, anal cancer, and multiple brain metastases, while MnTE-2-PyP5+ is in Phase II clinical trial on atopic dermatitis and itch.
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27

Takefuji, Yoshiyasu. "Set Operations in Python for Translational Medicine." International Journal of Translational Medicine 2, no. 2 (April 29, 2022): 174–85. http://dx.doi.org/10.3390/ijtm2020015.

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This is the world’s first tutorial article on Python programing on set operations for beginners and practitioners in translational medicine or medicine in general. This tutorial will allow researchers to demonstrate and showcase their tools on PyPI packages around the world. Via the PyPI packaging, a Python application with a single source code can run on Windows, MacOS, and Linux operating systems. In addition to the PyPI packaging, the reproducibility and quality of the source code must be guaranteed. This paper shows how to publish the Python application in Code Ocean after the PyPI packaging. Code Ocean is used in IEEE, Springer, and Elsevier for software reproducibility validation. First, programmers must understand how to scrape a dataset over the Internet. Second, the dataset files must be read in Python. Third, a program must be built to compute the target values using set operations. Fourth, the Python program must be converted to the PyPI package. Finally, the PyPI package is uploaded. Code Ocean plays a key role in publishing validation for software reproducibility. This paper depicts a vaers executable package as an example for calculating the number of deaths due to COVID-19 vaccines. Calculations were based on gender (male and female), age group, and vaccine group (Moderna, Pfizer, and Novartis), respectively.
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28

Sedykh, Alexander E., Robin Bissert, Dirk G. Kurth, and Klaus Müller-Buschbaum. "Structural diversity of salts of terpyridine derivatives with europium(III) located in both, cation and anion, in comparison to molecular complexes." Zeitschrift für Kristallographie - Crystalline Materials 235, no. 8-9 (September 25, 2020): 353–63. http://dx.doi.org/10.1515/zkri-2020-0053.

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AbstractThree salts of the common composition [EuCl2(X-tpy)2][EuCl4(X-tpy)]·nMeCN were obtained from EuCl3·6H2O and the respective organic ligands (X-tpy = 4′-phenyl-2,2′:6′,2″-terpyridine ptpy, 4′-(pyridin-4-yl)-2,2′:6′,2″-terpyridine 4-pytpy, and 4′-(pyridin-3-yl)-2,2′:6′,2″-terpyridine 3-pytpy). These ionic complexes are examples of salts, in which both cation and anion contain Eu3+ with the same organic ligands and chlorine atoms coordinated. As side reaction, acetonitrile transforms into acetamide resulting in the crystallization of the complex [EuCl3(ptpy)(acetamide)] (4). Salts [EuCl2(ptpy)2][EuCl4(ptpy)]·2.34MeCN (1), [EuCl2(4-pytpy)2][EuCl4(4-pytpy)]·0.11MeCN (2), and [EuCl2(3-pytpy)2][EuCl4(3-pytpy)]·MeCN (3) crystallize in different structures (varying in space group and crystal packing) due to variation of the rear atom of the ligand to a coordinative site. Additionally, we show and compare structural variability through the dimeric complexes [Eu2Cl6(ptpy)2(N,N′-spacer)]·N,N′-spacer (5, 6, 7) obtained from [EuCl3(ptpy)(py)] by exchanging the end-on ligand pyridine with several bipyridines (4,4′-bipyridine bipy, 1,2-bis(4-pyridyl)ethane bpa, and 1,2-bis(2-pyridyl)ethylene bpe). In addition, photophysical (photoluminescence) and thermal properties are presented.
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29

Lloyd, K. C., D. Grandt, K. Aurang, V. E. Eysselein, M. Schimiczek, and J. R. Reeve. "Inhibitory effect of PYY on vagally stimulated acid secretion is mediated predominantly by Y1 receptors." American Journal of Physiology-Gastrointestinal and Liver Physiology 270, no. 1 (January 1, 1996): G123—G127. http://dx.doi.org/10.1152/ajpgi.1996.270.1.g123.

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Two molecular forms of peptide YY (PYY), PYY-(1--36) and PYY-(3--36), are abundant in rabbit intestine and blood. We have previously shown that PYY-(1--36) (PYYI) activates equipotently Y1 and Y2 receptors and PYY-(3--36) (PYY II) is a highly selective agonist for Y2 receptors. In the present study, we examined the effect of exogenous infusion of PYY on vagally stimulated gastric acid secretion in awake rabbits with chronic gastric fistula. To determine the specific PYY receptor(s) that mediates this effect, we used a highly selective Y1 agonist, Pro34-PYY, a synthetic PYY, and a Y2-selective agonist, PYY II. Vagal stimulation of acid secretion was elicited by an intravenous bolus injection of insulin (0.125 U/kg) 30 min after beginning a 180-min intravenous infusion of either PYY I, PYY II, or [Pro34]-PYY after a 50 micrograms/kg i.v. bolus of atropine followed immediately by a 500 micrograms/kg sc injection. During infusion of 200 pmol.kg 1.h-1 PYY I, acid output was significantly inhibited to 45 +/- 13% of maximum acid output 60 min after injection of insulin. Similarly, acid output during infusion of 200 pmol.kg-1.h-1 [Pro34]-PYY was significantly inhibited to 52 +/- 12% of maximum. In contrast, acid output during infusion of 200 pmol.kg-1.h-1 of PYY II was not significantly inhibited (101 +/- 18% of maximum). Infusion of double the dose (400 pmol.kg-1.h-1) of PYY II resulted in acid inhibition (51 = 15% of maximum), whereas infusion of the same dose did not significantly enhance acid inhibition by infusion of either PYY I or [Pro34]-PYY (28 +/- 11 and 42 +/- 15% of maximum). These results indicate that PYY, acting predominantly at Y1 receptors, is a potent inhibitor of vagally stimulated acid secretion in adult rabbits.
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30

Chelikani, Prasanth K., Alvin C. Haver, and Roger D. Reidelberger. "Comparison of the inhibitory effects of PYY(3-36) and PYY(1-36) on gastric emptying in rats." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 287, no. 5 (November 2004): R1064—R1070. http://dx.doi.org/10.1152/ajpregu.00376.2004.

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We compared the effects of the two molecular forms of the brain-gut peptide YY (PYY), PYY(1-36) and PYY(3-36), on gastric emptying. Unanesthetized rats received 20-min intravenous infusions of rat PYY(1-36) (0, 1.7, 5, 17, 50, 100, 170 pmol·kg−1·min−1) and rat PYY(3-36) (0, 0.5, 1.7, 5, 17, 50, 100, 170 pmol·kg−1·min−1), either alone or combined, and gastric emptying of saline was measured during the last 10 min of infusion. For comparison, human PYY(3-36) was administered at 0, 17, and 50 pmol·kg−1·min−1. Gastric emptying was decreased by 11, 24, 26 and 38% in response to 17, 50, 100, and 170 pmol·kg−1·min−1 of rat PYY(1-36); by 10, 26, 41, 53, and 57% in response to 5, 17, 50, 100, and 170 pmol·kg−1·min−1 of rat PYY(3-36); and by 35 and 53% in response to 17 and 50 pmol·kg−1·min−1 of human PYY(3-36), respectively. Estimated ED50s were 470 and 37 pmol·kg−1·min−1 for rat PYY(1-36) and PYY(3-36), respectively. In general, within an experiment, coadministration of PYY(1-36) and PYY(3-36) inhibited gastric emptying by an amount that was comparable to that produced when either peptide was given alone. We conclude that 1) intravenous infusion of PYY(1-36) and PYY(3-36) each produces a dose-dependent inhibition of gastric emptying in rats, 2) PYY(3-36) is an order of magnitude more potent than PYY(1-36) in inhibiting gastric emptying, 3) human PYY(3-36) and rat PYY(3-36) inhibit gastric emptying similarly, and 4) PYY(1-36) and PYY(3-36) do not appear to interact in an additive or synergistic manner to inhibit gastric emptying.
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31

Schilling, Jennifer, Karin Wagner, Stephanie Seekircher, Lilo Greune, Verena Humberg, M. Alexander Schmidt, and Gerhard Heusipp. "Transcriptional Activation of the tad Type IVb Pilus Operon by PypB in Yersinia enterocolitica." Journal of Bacteriology 192, no. 14 (May 14, 2010): 3809–21. http://dx.doi.org/10.1128/jb.01672-09.

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ABSTRACT Type IV pili are virulence factors in various bacteria and mediate, among other functions, the colonization of diverse surfaces. Various subclasses of type IV pili have been identified, but information on pilus expression, biogenesis, and the associated phenotypes is sparse for the genus Yersinia. We recently described the identification of PypB as a transcriptional regulator in Yersinia enterocolitica. Here we show that the pypB gene is associated with the tad locus, a genomic island that is widespread among bacterial and archaeal species. The genetic linkage of pypB with the tad locus is conserved throughout the yersiniae but is not found among other bacteria carrying the tad locus. We show that the genes of the tad locus form an operon in Y. enterocolitica that is controlled by PypB and that pypB is part of this operon. The tad genes encode functions necessary for the biogenesis of the Flp subfamily of type IVb pili initially described for Aggregatibacter actinomycetemcomitans to mediate a tight-adherence phenotype. In Y. enterocolitica, the Flp pilin protein shows some peculiarities in its amino acid sequence that imply similarities as well as differences compared to typical motifs found in the Flp subtype of type IVb pili. Flp is expressed and processed after PypB overproduction, resulting in microcolony formation but not in increased adherence to biotic or abiotic surfaces. Our data describe the transcriptional regulation of the tad type IVb pilus operon by PypB in Y. enterocolitica but fail to show most previously described phenotypes associated with this type of pilus in other bacteria.
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32

Li, Lily, María de Guadalupe Jaraquemada-Peláez, Eduardo Aluicio-Sarduy, Xiaozhu Wang, Todd E. Barnhart, Weibo Cai, Valery Radchenko, Paul Schaffer, Jonathan W. Engle, and Chris Orvig. "Coordination chemistry of [Y(pypa)]− and comparison immuno-PET imaging of [44Sc]Sc- and [86Y]Y-pypa-phenyl-TRC105." Dalton Transactions 49, no. 17 (2020): 5547–62. http://dx.doi.org/10.1039/d0dt00437e.

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33

Keire, David A., Peter Mannon, Mitsuo Kobayashi, John H. Walsh, Travis E. Solomon, and Joseph R. Reeve. "Primary structures of PYY, [Pro34]PYY, and PYY-(3–36) confer different conformations and receptor selectivity." American Journal of Physiology-Gastrointestinal and Liver Physiology 279, no. 1 (July 1, 2000): G126—G131. http://dx.doi.org/10.1152/ajpgi.2000.279.1.g126.

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We synthesized PYY-(1–36) (nonselective between Y1 and Y2 receptor subtype agonists), [Pro34]PYY (selective for Y1), and PYY-(3–36) (selective for Y2) to determine whether solution conformation plays a role in receptor subtype selectivity. The three peptides exhibited the expected specificities in displacing labeled PYY-(1–36) from cells transfected with Y1receptors (dissociation constants = 0.42, 0.21, and 1,050 nM, respectively) and from cells transfected with Y2 receptors (dissociation constants = 0.03, 710, and 0.11 nM, respectively) for PYY-(1–36), [Pro34]PYY, and PYY-(3–36). Sedimentation equilibrium analyses revealed that the three PYY analogs were 80–90% monomer at the concentrations used for the subsequent circular dichroism (CD) and1H-nuclear magnetic resonance (NMR) studies. CD analysis measured helicities for PYY-(1–36), [Pro34]PYY, and PYY-(3–36) of 42%, 31%, and 24%, suggesting distinct differences in secondary structure. The backbone 1H-NMR resonances of the three peptides further substantiated marked conformational differences. These patterns support the hypothesis that Y1 and Y2 receptor subtype binding affinities depend on the secondary and tertiary solution state structures of PYY and its analogs.
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34

Nielsen, S., S. P. Sheikh, M. I. Sheikh, and E. I. Christensen. "Peptide YY luminal processing and axial heterogeneity of basolateral binding in renal proximal tubules." American Journal of Physiology-Renal Physiology 260, no. 3 (March 1, 1991): F359—F367. http://dx.doi.org/10.1152/ajprenal.1991.260.3.f359.

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This study investigates the definite location of peptide YY (PYY) binding sites on the basolateral membranes in proximal tubules. S1, S2, and S3 segments were dissected, perfused in vitro, and exposed to [125I-Tyr36]monoiodo-PYY either in the bath fluid or in the perfusate. S1 segments exposed to [125I-Tyr36]PYY in the bath fluid were fixed and prepared for electron microscope autoradiography. The results demonstrated a high degree of axial heterogeneity of basolateral binding of PYY, since only S1 bound PYY, 0.59 +/- 0.09 pg/mm after 15 min; 89.1% could be displaced with unlabeled PYY. PYY was not internalized, 90% of the grains were associated with the basolateral membranes, and no accumulation of grains was observed over the vacuolar apparatus. After luminal perfusion with PYY, 79.3 +/- 7.2% was processed, 61.7 +/- 6.3% was degraded at the brush border, and no tubular accumulation was detected. Thus PYY is not taken up by endocytosis. Unexpectedly, a very large fraction of processed PYY was transported from lumen to bath as trichloroacetic acid (TCA)-precipitable label constituting 41.6 +/- 4.7%. There was no axial heterogeneity in the luminal handling of PYY. In conclusion, this study reveals a high density of PYY binding sites at the basolateral membranes from S1 segments, indicating a selective function of S1 segments on stimulation with PYY. In contrast to other proteins PYY was not internalized from the basolateral membranes.
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35

Gelegen, C., K. Chandarana, A. I. Choudhury, H. Al-Qassab, I. M. Evans, E. E. Irvine, C. B. Hyde, et al. "Regulation of hindbrainPyyexpression by acute food deprivation, prolonged caloric restriction, and weight loss surgery in mice." American Journal of Physiology-Endocrinology and Metabolism 303, no. 5 (September 1, 2012): E659—E668. http://dx.doi.org/10.1152/ajpendo.00033.2012.

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PYY is a gut-derived putative satiety signal released in response to nutrient ingestion and is implicated in the regulation of energy homeostasis. Pyy-expressing neurons have been identified in the hindbrain of river lamprey, rodents, and primates. Despite this high evolutionary conservation, little is known about central PYY neurons. Using in situ hybridization, PYY-Cre;ROSA-EYFP mice, and immunohistochemistry, we identified PYY cell bodies in the gigantocellular reticular nucleus region of the hindbrain. PYY projections were present in the dorsal vagal complex and hypoglossal nucleus. In the hindbrain, Pyy mRNA was present at E9.5, and expression peaked at P2 and then decreased significantly by 70% at adulthood. We found that, in contrast to the circulation, PYY-(1–36) is the predominant isoform in mouse brainstem extracts in the ad libitum-fed state. However, following a 24-h fast, the relative amounts of PYY-(1–36) and PYY-(3–36) isoforms were similar. Interestingly, central Pyy expression showed nutritional regulation and decreased significantly by acute starvation, prolonged caloric restriction, and bariatric surgery (enterogastroanastomosis). Central Pyy expression correlated with body weight loss and circulating leptin and PYY concentrations. Central regulation of energy metabolism is not limited to the hypothalamus but also includes the midbrain and the brainstem. Our findings suggest a role for hindbrain PYY in the regulation of energy homeostasis and provide a starting point for further research on gigantocellular reticular nucleus PYY neurons, which will increase our understanding of the brain stem pathways in the integrated control of appetite and energy metabolism.
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36

Whalen, Kevin G., and Donna L. Parrish. "Nocturnal habitat use of Atlantic salmon parr in winter." Canadian Journal of Fisheries and Aquatic Sciences 56, no. 9 (September 1, 1999): 1543–50. http://dx.doi.org/10.1139/f99-078.

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We completed 22 night snorkeling surveys between November and March 1995-1997 to quantify Atlantic salmon (Salmo salar) parr habitat use relative to habitat availability in the Rock River, Vermont, U.S.A. On average, post-young-of-the-year (PYOY) parr selected greater water depths in winter than young-of-the-year (YOY) parr, whereas YOY and PYOY parr both selected water velocities ([Formula: see text]19 cm/s) that were significantly lower than random measurements (46 cm/s). Maturity of PYOY parr had no significant influence on habitat selection. The majority of YOY and PYOY parr at night were found in contact with the stream bottom resting on silt-sand or gravel substrates in velocity dead-zone habitats created by the stream edge or depositional habitats created by midstream rocks and boulders. The strong selection that nocturnal Atlantic salmon parr exhibit for low water velocity areas in winter indicates the importance of maintaining large instream cover that provides refuges from high flows. The similarity that YOY and PYOY parr exhibited in many elements of habitat selection suggests that both stages may be similarly susceptible to habitat limitations in winter.
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37

Kawakubo, Keishi, Hong Yang, and Yvette Taché. "Gastric protective effect of peripheral PYY through PYY preferring receptors in anesthetized rats." American Journal of Physiology-Gastrointestinal and Liver Physiology 283, no. 5 (November 1, 2002): G1035—G1041. http://dx.doi.org/10.1152/ajpgi.00154.2002.

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The influence of intravenous peptide YY (PYY) on the gastric injury induced by 45% ethanol was investigated in urethane-anesthetized rats. PYY (25, 75, 125, and 250 pmol · kg−1 · h−1) significantly reduced gastric lesions by 36, 59, 40, and 38%, respectively. Antibody against ratPYY (2 mg/rat) injected intravenously completely prevented the gastroprotective effect of intravenous PYY (75 pmol · kg−1 · h−1), whereas injected intracisternally (460 μg/20 μl), it significantly prevented intracisternal PYY (24 pmol/rat)-induced 58% reduction of ethanol lesions but not that induced by intravenous PYY. Vagotomy did not influence the gastroprotective effect of intravenous PYY. The Y1/“PYY-preferring” receptor agonist [Pro34]PYY (75 pmol · kg−1 ·h−1iv) significantly decreased ethanol-induced gastric lesions by 82%, whereas [Leu31, Pro34]NPY, a Y1/Y3 agonist, and PYY-(3–36), a Y2 agonist, had no effect. These data indicate that PYY-infused intravenously at doses reported to mimic postprandial peak blood levels prevents ethanol-induced gastric injury through vagal independent pathways and PYY-preferring receptors.
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38

Choi, Mihwa, Jun Ozeki, Masami Hashizume, Shigeaki Kato, Hisamitsu Ishihara, and Makoto Makishima. "Vitamin D Receptor Activation Induces Peptide YY Transcription in Pancreatic Islets." Endocrinology 153, no. 11 (November 1, 2012): 5188–99. http://dx.doi.org/10.1210/en.2012-1396.

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Abstract Peptide YY (PYY) is a peptide hormone secreted from L cells in the intestine after food intake and regulates appetite and intestinal function. PYY is also expressed in the pancreas, but the mechanisms of regulation of pancreatic PYY expression have not been elucidated. The vitamin D receptor (VDR) is a nuclear receptor for the active form of vitamin D3 and regulates numerous physiological processes. Because VDR is expressed in the pancreas, we investigated the role of pancreatic VDR activation and found that Pyy is a VDR target gene in the mouse pancreas. Treatment of mice with 1α-hydroxyvitamin D3 increased plasma PYY levels. VDR activation increased mRNA and protein expression of PYY in the pancreatic islets of mice and pancreatic endocrine cell lines but did not change intestinal PYY expression. 1α-Hydroxyvitamin D3-dependent induction of pancreatic and plasma PYY was abolished in VDR-null mice. We identified a functional vitamin D-responsive element in the mouse Pyy promoter using chromatin immunoprecipitation assay, EMSA, and luciferase promoter assay. Thus, Pyy is a tissue-specific VDR target gene. The pancreatic VDR-PYY pathway may mediate a regulatory function of vitamin D in the neuroendocrine system.
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39

Shiozaki, K., M. Shiozaki, and P. Russell. "Mcs4 mitotic catastrophe suppressor regulates the fission yeast cell cycle through the Wik1-Wis1-Spc1 kinase cascade." Molecular Biology of the Cell 8, no. 3 (March 1997): 409–19. http://dx.doi.org/10.1091/mbc.8.3.409.

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Spc1 in Schizosaccharomyces pombe is a member of the stress-activated protein kinase family, an evolutionary conserved subfamily of mitogen-activated protein kinases (MAPKs). Spc1 is activated by a MAPK kinase homologue, Wis1, and negatively regulated by Pyp1 and Pyp2 tyrosine phosphatases. Mutations in the spc1+ and wis1+ genes cause a G2 cell cycle delay that is exacerbated during stress. Herein, we describe two upstream regulators of the Wis1-Spc1 cascade. wik1+ (Wis1 kinase) was identified from its homology to budding yeast SSK2, which encodes a MAPKK kinase that regulates the HOG1 osmosensing pathway. Delta wik1 cells are impaired in stress-induced activation of Spc1 and show a G2 cell cycle delay and osmosensitive growth. Moreover, overproduction of a constitutively active form of Wik1 induces hyperactivation of Spc1 in wis1(+)-dependent manner, suggesting that Wik1 regulates Spc1 through activation of Wis1. A mutation of mcs4+ (mitotic catastrophe suppressor) was originally isolated as a suppressor of the mitotic catastrophe phenotype of a cdc2-3w wee1-50 double mutant. We have found that mcs4- cells are defective at activation of Spc1 in response to various forms of stress. Epistasis analysis has placed Mcs4-upstream of Wik1 in the Spc1 activation cascade. These results indicate that Mcs4 is part of a sensor system for multiple environmental signals that modulates the timing of entry into mitosis by regulating the Wik1-Wis1-Spc1 kinase cascade. Inactivation of the sensor system delays the onset of mitosis and rescues lethal premature mitosis in cdc2-3w wee1-50 cells.
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40

Hill, Brenna R., Mary Jane De Souza, and Nancy I. Williams. "Characterization of the diurnal rhythm of peptide YY and its association with energy balance parameters in normal-weight premenopausal women." American Journal of Physiology-Endocrinology and Metabolism 301, no. 2 (August 2011): E409—E415. http://dx.doi.org/10.1152/ajpendo.00171.2011.

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PYY may play a role in modulating satiety and energy expenditure; increasing PYY postprandially has been studied largely in single-meal responses. The diurnal rhythm of PYY and its role in energy balance have not been fully characterized. The purpose of our study was to characterize features of the diurnal rhythm of PYY and determine its role in regulating energy balance. This study was a cross-sectional analysis of 11 subjects in whom 24-h repeated blood sampling was conducted at baseline of a larger prospective study. Breakfast (B), lunch (L), dinner (D), and a snack (S) occurred between 0900 and 1900. Total PYY was assayed every hour from 0800 to 1000, every 20 min from 1000 to 2000, and every hour from 2000 to 0800. PYY variables included total AUC, postprandial peaks, and 24-h mean. Energy balance variables included energy intake, RMR, RQ, and NEAT. PYY postprandial peaks were significantly higher than fasting ( P < 0.05). Twenty-four-hour peak PYY occurred after L and was significantly higher than all other peaks ( P < 0.05). A cubic curve function accounted for most of the variance in PYY ( r2 = 69.9%, P < 0.01). Fasting PYY (0800) correlated with postprandial peaks at B ( r = 0.77, P = 0.01), L ( r = 0.71, P = 0.01), and D ( r = 0.65, P = 0.03). The only significant association between PYY and energy expenditure was that RMR (kcal/24 h) correlated with 24-h mean PYY ( r = 0.71, P = 0.013) and total AUC ( r = 0.69, P = 0.019). We conclude that PYY displays a meal-driven diurnal rhythm and is correlated to RMR, a major contributor to energy expenditure. Thus, PYY varies in accordance with energy content and RMR, supporting a role for PYY in energy balance modulation.
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41

Plaisancié, P., V. Dumoulin, J.-A. Chayvialle, and J.-C. Cuber. "Luminal peptide YY-releasing factors in the isolated vascularly perfused rat colon." Journal of Endocrinology 151, no. 3 (December 1996): 421–29. http://dx.doi.org/10.1677/joe.0.1510421.

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Abstract Peptide YY (PYY) is produced in endocrine L cells primarily localized in the distal bowel. These open-type L cells make contact with the intestinal chyme which may thus affect their secretory activity. The aim of the present study was to examine a large variety of luminal compounds found in colonic contents for their potential as PYY-releasing factors, using the isolated vascularly perfused rat colon. The release of PYY into the portal effluent was measured by a specific RIA. Luminal administration of 5 mm glucose or 0·5% (w/v) starch for 30 min did not induce significant release of PYY. Oleic acid (10 and 100 mm) also did not significantly increase PYY secretion. A pharmacological concentration of glucose (250 mm) and a mixture of amino acids (total concentration 250 mm) both induced PYY secretion (200% of basal). Pectin, a polygalacturonic acid, evoked dose-dependent secretion of PYY-like immunoreactivity over the range 0·1–0·5% (w/v). The maximal response was observed after infusion of 0·5% pectin which induced a prompt and sustained release of PYY (300% of basal). Galacturonic acid itself (5%) produced marked PYY secretion. Gum arabic (0·5%) induced a gradual increase in portal PYY concentration (maximal response 250% of the basal value) whereas cellulose (0·5%) did not elicit PYY secretion. Luminal n-butyrate over the range 0·5–5 mm produced a dose-dependent release of PYY (maximal response 300% of the basal value with 5 mm n-butyrate). Increasing the concentration of n-butyrate to 100 mm provoked a gradual decrease in PYY secretion. Propionate was a less potent stimulant than n-butyrate, and acetate did not increase PYY secretion above the basal value. At a concentration of 2 or 20 mm, taurocholate, cholate and deoxycholate brought about PYY secretion while hyodeoxycholate was without effect. In conclusion, glucose and amino acids may mediate PYY release but only when they are present at high supraphysiological concentrations in the colon while oleic acid does not produce any PYY secretion. Physiological concentrations of fibers (pectin, gum arabic), short-chain fatty acids (n-butyrate, propionate) and bile salts (taurocholate, cholate, deoxycholate) are all potent stimulants of PYY release. Whether the release of PYY by luminal factors is coupled to water and electrolyte transfer via a local/paracrine pathway remains an open question which requires additional work with the isolated vascularly perfused colon preparation. Journal of Endocrinology (1996) 151, 421–429
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42

Olson, Kenneth R., Yan Gao, Faihaan Arif, Shivali Patel, Xiaotong Yuan, Varun Mannam, Scott Howard, et al. "Manganese Porphyrin-Based SOD Mimetics Produce Polysulfides from Hydrogen Sulfide." Antioxidants 8, no. 12 (December 12, 2019): 639. http://dx.doi.org/10.3390/antiox8120639.

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Manganese-centered porphyrins (MnPs), MnTE-2-PyP5+ (MnTE), MnTnHex-2-PyP5+ (MnTnHex), and MnTnBuOE-2-PyP5+ (MnTnBuOE) have received considerable attention because of their ability to serve as superoxide dismutase (SOD) mimetics thereby producing hydrogen peroxide (H2O2), and oxidants of ascorbate and simple aminothiols or protein thiols. MnTE-2-PyP5+ and MnTnBuOE-2-PyP5+ are now in five Phase II clinical trials warranting further exploration of their rich redox-based biology. Previously, we reported that SOD is also a sulfide oxidase catalyzing the oxidation of hydrogen sulfide (H2S) to hydrogen persulfide (H2S2) and longer-chain polysulfides (H2Sn, n = 3–7). We hypothesized that MnPs may have similar actions on sulfide metabolism. H2S and polysulfides were monitored in fluorimetric assays with 7-azido-4-methylcoumarin (AzMC) and 3′,6′-di(O-thiosalicyl)fluorescein (SSP4), respectively, and specific polysulfides were further identified by mass spectrometry. MnPs concentration-dependently consumed H2S and produced H2S2 and subsequently longer-chain polysulfides. This reaction appeared to be O2-dependent. MnP absorbance spectra exhibited wavelength shifts in the Soret and Q bands characteristic of sulfide-mediated reduction of Mn. Taken together, our results suggest that MnPs can become efficacious activators of a variety of cytoprotective processes by acting as sulfide oxidation catalysts generating per/polysulfides.
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43

Gomez, G., T. Zhang, S. Rajaraman, K. N. Thakore, N. Yanaihara, C. M. Townsend, J. C. Thompson, and G. H. Greeley. "Intestinal peptide YY: ontogeny of gene expression in rat bowel and trophic actions on rat and mouse bowel." American Journal of Physiology-Gastrointestinal and Liver Physiology 268, no. 1 (January 1, 1995): G71—G81. http://dx.doi.org/10.1152/ajpgi.1995.268.1.g71.

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The purpose of this study was twofold: 1) to characterize the profile of colonic peptide YY (PYY) gene expression in rats and 2) to examine for potential trophic effects of PYY on the intestine in rats and mice. Expression of PYY mRNA (analyzed by Northern blotting and in situ hybridization) and PYY (analyzed by high-performance liquid chromatography and radioimmunoassay) was detected initially at day 17 of gestation in colonic extracts of Sprague-Dawley and Fischer rats. Expression of colonic PYY mRNA increased until 7 days of age and remained at its highest level (approximately twofold greater than the adult level) through the end of the nursing period. After weaning (21 days of age), PYY mRNA levels declined quickly to adult levels. Colonic PYY concentrations followed, in a coordinated manner, with some temporal delay after birth, the increase and decrease of its mRNA. Administration of PYY increased the weight and DNA content of the duodenum significantly in nursing rats and adult mice. In mice, PYY treatment also increased weight and DNA content of the ileum and colon. The trophic effects of PYY were dose related, peptide specific, and independent of species and sex. From these findings, we hypothesize that PYY plays an important role in intestinal development and dietary adaptation.
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44

Yang, Hong, Keishi Kawakubo, Helen Wong, Gordon Ohning, John Walsh, and Yvette Taché. "Peripheral PYY inhibits intracisternal TRH-induced gastric acid secretion by acting in the brain." American Journal of Physiology-Gastrointestinal and Liver Physiology 279, no. 3 (September 1, 2000): G575—G581. http://dx.doi.org/10.1152/ajpgi.2000.279.3.g575.

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The site of action of peripheral peptide YY (PYY)-induced inhibition of vagally stimulated gastric acid secretion was studied using immunoneutralization with PYY antibody in urethan-anesthetized rats. Gastric acid secretion (59 ± 7 μmol/90 min) stimulated by intracisternal injection of the stable thyrotropin-releasing hormone (TRH) analog RX-77368 (14 pmol/rat) was dose-dependently inhibited by 52%, 69%, and 83% by intravenous infusion of 0.25, 0.5, and 1.0 nmol · kg−1 · h−1 PYY, respectively. PYY or PYY3–36 (2.4 pmol/rat) injected intracisternally also inhibited the acid response to intracisternal RX-77368 by 73% and 80%, respectively. Intravenous pretreatment with PYY antibody (4.5 mg/rat), which shows a 35% cross-reaction with PYY3–36 by RIA, completely prevented the inhibitory effect of intravenously infused PYY (1 nmol · kg−1 · h−1). When injected intracisternally, the PYY antibody (280 μg/rat) reversed intracisternal PYY (2.4 pmol)- and intravenous PYY (1 nmol · kg−1 · h−1)-induced inhibition of acid response to intracisternal RX-77368 by 64% and 93.5%, respectively. These results provide supporting evidence that peripheral PYY inhibits central vagal stimulation of gastric acid secretion through an action in the brain.
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45

Voisin, T., C. Rouyer-Fessard, and M. Laburthe. "Distribution of common peptide YY-neuropeptide Y receptor along rat intestinal villus-crypt axis." American Journal of Physiology-Gastrointestinal and Liver Physiology 258, no. 5 (May 1, 1990): G753—G759. http://dx.doi.org/10.1152/ajpgi.1990.258.5.g753.

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Rat small intestinal epithelium is equipped with peptide YY (PYY)-preferring receptors, which also recognize neuropeptide Y (NPY) with high affinity. We therefore examined the distribution of PYY-NPY receptors along the villus-crypt axis after separation of mature villus cells from proliferative crypt cells. Specific 125I-labeled PYY binding was nine times higher in crypt cells than in villus cells. This was not due to differential degradation of PYY or PYY binding sites by the two cell populations. Rather, Scatchard analysis of equilibrium binding data showed that binding capacity (Bmax) of receptors increased from villus to crypt. Bmax were 166 +/- 36 and 21 +/- 3 fmol/mg protein, and dissociation constants (Kd) were 0.10 +/- 0.02 and 0.05 +/- 0.02 nM in crude membranes prepared from crypt and villus cells, respectively. For all cell populations, NPY and rat pancreatic polypeptide were 8- and 1,800-fold less potent than PYY in inhibiting 125I-PYY binding, respectively. Therefore, receptors appear to be PYY preferring along the entire villus-crypt axis. Both peptides (at the maximally active concentration of 1 microM) reduced vasoactive intestinal peptide (VIP)-stimulated adenosine 3',5'-cyclic monophosphate (cAMP) by 50% in crypt cells. PYY was four to six times more potent than NPY in agreement with the expression of a PYY-preferring receptor. By contrast, neither PYY nor NPY altered VIP-stimulated cAMP levels in villus cells. These results indicate that PYY-preferring receptors, negatively coupled to the cAMP production system, are preferentially expressed in crypt cells where intestinal ionic secretion is believed to take place.
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46

Narayanan, Sumaletha, Xia Tong, and Venkataraman Thangadurai. "The synthesis and electrical properties of hybrid gel electrolytes derived from Keggin-type heteropoly acids and 3-(pyridin-1-ium-1-yl)propane-1-sulfonate (PyPs)." RSC Advances 6, no. 104 (2016): 102549–56. http://dx.doi.org/10.1039/c6ra23082b.

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Cyclic voltammetry of PyPs–H3PWMo at room temperature between −4 and +4 V vs. Ag/AgCl at a 10 mV s−1 scan rate and comparison of electrical conductivity of PyPs–H3PWMo with other known promising proton conductors.
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47

Guo, Y. S., M. Fujimura, F. Lluis, Y. Tsong, G. H. Greeley, and J. C. Thompson. "Inhibitory action of peptide YY on gastric acid secretion." American Journal of Physiology-Gastrointestinal and Liver Physiology 253, no. 3 (September 1, 1987): G298—G302. http://dx.doi.org/10.1152/ajpgi.1987.253.3.g298.

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The purpose of this study is to investigate the effect of peptide YY (PYY) on pentagastrin-, histamine-, and bethanechol-stimulated gastric acid secretion and the possible mechanisms by which PYY inhibits gastric acid secretion. Six mongrel dogs with chronic gastric and duodenal fistulas were given an intravenous infusion of pentagastrin (0.5 microgram . kg-1 . h-1), histamine (18 micrograms . kg-1 . h-1), or bethanechol (80 micrograms . kg-1 . h-1) either alone or simultaneously with intravenous PYY (100, 200, 400, pmol . kg-1 . h-1). PYY (100, 200, 400 pmol . kg-1 . h-1) inhibited pentagastrin-stimulated gastric acid secretion in a dose-dependent manner. PYY (400 pmol . kg-1 . h-1) did not depress bethanechol-stimulated gastric acid secretion. PYY (400 pmol . kg-1 . h-1) also failed to inhibit histamine-stimulated gastric acid secretion. Furthermore, PYY inhibit pentagastrin-stimulated gastric acid secretion in the face of atropine, vagotomy, or indomethacin treatment. These findings indicate that the inhibitory action of PYY on gastric acid secretion is in part independent of long and short cholinergic pathways. These findings also indicate that the inhibitory mechanism of PYY is independent of prostaglandin synthesis. Our findings are discussed in relation to previous reports regarding the effects of PYY on gastric acid secretion.
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48

Izzi-Engbeaya, Chioma, Sophie Jones, Yoshibye Crustna, Pratibha C. Machenahalli, Deborah Papadopoulou, Manish Modi, Christos Panayi, et al. "Effects of Peptide YY on the Hypothalamic-Pituitary-Gonadal Axis in Healthy Men." Journal of Clinical Endocrinology & Metabolism 105, no. 3 (October 19, 2019): 833–38. http://dx.doi.org/10.1210/clinem/dgz103.

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Abstract Context Central and peripheral administration of peptide YY (PYY) has potent anorectic effects, and PYY analogs are under development as antiobesity treatments. Recent animal data suggest PYY may also influence the reproductive axis; however the effects of PYY on the human reproductive system are unknown. Objective To investigate the effects of PYY administration on the reproductive axis in healthy young men. Design Single-blind, randomized, placebo-controlled crossover study. Setting Clinical Research Facility, Imperial College Healthcare NHS Trust. Participants Eighteen healthy eugonadal men (mean age 24.1 ± 0.9 years, mean body mass index 22.2 ± 0.4 kg/m2). Intervention Eight-hour intravenous infusion of 0.4 pmol/kg/min PYY3-36 or rate-matched vehicle infusion. Main Outcome Measures Number of luteinizing hormone (LH) pulses, LH, follicle stimulating hormone (FSH), and testosterone levels. Results The number of LH pulses (mean number of LH pulses/8 hours: PYY 4.4 ± 0.3 vs vehicle 4.4 ± 0.4, P &gt; .99), LH area under the curve (AUC) (PYY 1503 ± 79 IU.min/L vs vehicle 1574 ± 86 IU.min/L, P = .36), FSH AUC (PYY 1158 ± 513 IU.min/L vs vehicle 1199 ± 476 IU.min/L, P = .49) and testosterone AUC (PYY 10 485 ± 684 IU.min/L vs vehicle 11 133 ± 803 IU.min/L, P = .24) were similar during PYY and vehicle infusions. Conclusions Acute intravenous infusion of 0.4 pmol/kg/min PYY does not affect the reproductive axis in healthy men.
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49

Rigamonti, Antonello E., Silvano G. Cella, Sara M. Bonomo, Giuseppe Mancia, Guido Grassi, Mario Perotti, Fiorenza Agosti, Alessandro Sartorio, Eugenio E. Müller, and Angela I. Pincelli. "Effect of somatostatin infusion on peptide YY secretion: studies in the acute and recovery phase of anorexia nervosa and in obesity." European Journal of Endocrinology 165, no. 3 (September 2011): 421–27. http://dx.doi.org/10.1530/eje-11-0312.

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ObjectiveChanges in many gastrointestinal peptides, including the anorexigenic peptide YY (PYY), which is produced by L cells, occur in both anorexia nervosa (AN) and obesity (OB). High PYY levels are present in AN, whereas in morbid OB fasting and postprandial PYY secretion is blunted. Somatostatin (somatotropin release-inhibiting factor (SRIF)) reportedly inhibits plasma PYY concentrations in animals and healthy humans, but the effect of a SRIF infusion on spontaneous PYY secretion in AN and OB is unknown.MethodsA total of 18 young women, seven with acute AN (A-AN), four with AN in the recovery phase (R-AN), and seven with morbid OB, were studied. All subjects underwent an infusion of SRIF (9 μg/kg i.v./h, over 60 min), with blood samples drawn before and at different time intervals after SRIF administration. Plasma PYY levels were measured at each time point.ResultsSRIF significantly inhibited plasma PYY concentrations in R-AN and OB, without affecting PYY titers in A-AN. In OB, the inhibitory effect of SRIF also persisted at 90 min. Withdrawal of SRIF infusion in R-AN resulted in a prompt restoration of basal plasma PYY levels, whereas termination of SRIF infusion in OB was followed by a slower increase of PYY titers toward baseline levels. After infusion, PYY Δ area under the curve (ΔAUC) in R-AN was significantly higher than those in A-AN and OB patients. A significant difference in PYY ΔAUC between A-AN and OB was present.ConclusionsThese results suggest the existence of a hypo- and hyper-sensitivity of L cells to the inhibitory effect of SRIF in A-AN and OB respectively.
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50

Ballantyne, G. H., J. R. Goldenring, F. X. Fleming, S. Rush, J. S. Flint, L. P. Fielding, H. J. Binder, and I. M. Modlin. "Inhibition of VIP-stimulated ion transport by a novel Y-receptor phenotype in rabbit distal colon." American Journal of Physiology-Gastrointestinal and Liver Physiology 264, no. 5 (May 1, 1993): G848—G854. http://dx.doi.org/10.1152/ajpgi.1993.264.5.g848.

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Neurocrine, endocrine, and paracrine regulators are critical to the control of colonic secretion. These studies have investigated the inhibition of vasoactive intestinal polypeptide (VIP)-stimulated ion transport by peptide YY (PYY) and other Y-class effectors in rabbit distal colonic mucosa mounted in Ussing chambers. PYY decreased basal short-circuit current (Isc) but did not significantly change either basal Na+ or Cl- flux. PYY inhibited VIP-stimulated increases in Isc by up to 86% and abolished VIP-induced Cl- secretion. PYY decreased VIP-generated increases in Isc by a tetrodotoxin-insensitive mechanism. PYY inhibited cholera toxin-stimulated as well as forskolin-stimulated increases in Isc but failed to alter stimulation by 8-bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP). PYY decreased VIP-stimulated increases in tissue cAMP by 88% and forskolin-stimulated increases by 84%. PYY, neuropeptide Y (NPY), (Leu31,Pro34)-NPY, and pancreatic polypeptide (PP) all demonstrated potent inhibition of VIP-stimulated increases in Isc. PYY-(13-36) demonstrated little effect on VIP stimulation. Thus the rabbit distal colon possesses a novel Y-class receptor phenotype that demonstrates high affinity for all three PP-fold peptides, NPY, PYY, and PP.
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