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102 records – page 1 of 11.

[Age-dependent effects of flavonoids on secretory function of the rat liver]

https://arctichealth.org/en/permalink/ahliterature83213
Source
Fiziol Zh. 2005;51(4):65-9
Publication Type
Article
Date
2005
Author
Babenko N O
Shakhova O H
Source
Fiziol Zh. 2005;51(4):65-9
Date
2005
Language
Ukrainian
Publication Type
Article
Keywords
Aging - drug effects - metabolism
Animals
Bile - chemistry - secretion
Bile Acids and Salts - secretion
Cholesterol - secretion
Dose-Response Relationship, Drug
Flavonoids - isolation & purification - pharmacology
Liver - drug effects - metabolism
Male
Matricaria - chemistry
Rats
Abstract
The effects of the chamomilla recutita (1) flavonoids (chamiloflan) on bilegenesis of the adult and old white rats were investigated. Chamiloflan (20, 40 and 80 mg/kg) induced a dose-dependent increase in the bile flow and bile acid secretion in rats of both age groups. Cholesterol concentration in the liver and bile cholesterol secretion were not changed in the treated adult rats. Chamiloflan increased cholesterol bile secretion and reduced lipid content in the liver of the old rats.
PubMed ID
16201153 View in PubMed
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Alpha-methylacyl-CoA racemase from Mycobacterium tuberculosis. Mutational and structural characterization of the active site and the fold.

https://arctichealth.org/en/permalink/ahliterature69307
Source
J Biol Chem. 2005 Apr 1;280(13):12611-20
Publication Type
Article
Date
Apr-1-2005
Author
Kalle Savolainen
Prasenjit Bhaumik
Werner Schmitz
Tiina J Kotti
Ernst Conzelmann
Rik K Wierenga
J Kalervo Hiltunen
Author Affiliation
Biocenter Oulu and Department of Biochemistry, University of Oulu, Linnanmaa, P. O. Box 3000, FIN-90014 University of Oulu, Finland.
Source
J Biol Chem. 2005 Apr 1;280(13):12611-20
Date
Apr-1-2005
Language
English
Publication Type
Article
Keywords
Alanine - chemistry
Amino Acid Sequence
Animals
Bile Acids and Salts - metabolism
Binding Sites
Catalysis
Circular Dichroism
Cloning, Molecular
Crystallography, X-Ray
Dimerization
Escherichia coli - metabolism
Models, Chemical
Models, Molecular
Molecular Sequence Data
Mutation
Mycobacterium tuberculosis - enzymology - genetics
Protein Conformation
Protein Folding
Protein Structure, Secondary
Racemases and Epimerases - chemistry - genetics
Rats
Research Support, Non-U.S. Gov't
Sequence Homology, Amino Acid
Substrate Specificity
Ultraviolet Rays
Abstract
Alpha-methylacyl-CoA racemase (Amacr) catalyzes the racemization of alpha-methyl-branched CoA esters. Sequence comparisons have shown that this enzyme is a member of the family III CoA transferases. The mammalian Amacr is involved in bile acid synthesis and branched-chain fatty acid degradation. In human, mutated variants of Amacr have been shown to be associated with disease states. Amino acid sequence alignment of Amacrs and its homologues from various species revealed 26 conserved protic residues, assumed to be potential candidates as catalytic residues. Amacr from Mycobacterium tuberculosis (MCR) was taken as a representative of the racemases. To determine their importance for efficient catalysis, each of these 26 protic residues of MCR was mutated into an alanine, respectively, and the mutated variants were overexpressed in Escherichia coli. It was found that four variants (R91A, H126A, D156A, and E241A) were properly folded but had much decreased catalytic efficiency. Apparently, Arg91, His126, Asp156, and Glu241 are important catalytic residues of MCR. The importance of these residues for catalysis can be rationalized by the 1.8 A resolution crystal structure of MCR, which shows that the catalytic site is at the interface between the large and small domain of two different subunits of the dimeric enzyme. This crystal structure is the first structure of a complete enzyme of the bile acid synthesis pathway. It shows that MCR has unique structural features, not seen in the structures of the sequence related formyl-CoA transferases, suggesting that the family III CoA transferases can be subdivided in at least two classes, being racemases and CoA transferases.
PubMed ID
15632186 View in PubMed
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An integrated transcriptomic and comparative genomic analysis of differential gene expression in Arctic charr (Salvelinus alpinus) following seawater exposure.

https://arctichealth.org/en/permalink/ahliterature264847
Source
J Exp Biol. 2014 Nov 15;217(Pt 22):4029-42
Publication Type
Article
Date
Nov-15-2014
Author
Joseph D Norman
Moira M Ferguson
Roy G Danzmann
Source
J Exp Biol. 2014 Nov 15;217(Pt 22):4029-42
Date
Nov-15-2014
Language
English
Publication Type
Article
Keywords
Animals
Base Sequence
Biological Evolution
Gene Expression Profiling
Gene Ontology
Genomics
Molecular Sequence Data
Osmoregulation - genetics
Salinity
Salt-Tolerance
Seawater
Sequence Analysis, RNA
Transcriptome
Trout - genetics - metabolism
Water-Electrolyte Balance
Abstract
High-throughput RNA sequencing was used to compare expression profiles in two Arctic charr (Salvelinus alpinus) families post-seawater exposure to identify genes and biological processes involved in hypo-osmoregulation and regulation of salinity tolerance. To further understand the genetic architecture of hypo-osmoregulation, the genomic organization of differentially expressed (DE) genes was also analysed. Using a de novo gill transcriptome assembly we found over 2300 contigs to be DE. Major transporters from the seawater mitochondrion-rich cell (MRC) complex were up-regulated in seawater. Expression ratios for 257 differentially expressed contigs were highly correlated between families, suggesting they are strictly regulated. Based on expression profiles and known molecular pathways we inferred that seawater exposure induced changes in methylation states and elevated peroxynitrite formation in gill. We hypothesized that concomitance between DE immune genes and the transition to a hypo-osmoregulatory state could be related to Cl(-) sequestration by antimicrobial defence mechanisms. Gene ontology analysis revealed that cell division genes were up-regulated, which could reflect the proliferation of ATP1a1b-type seawater MRCs. Comparative genomics analyses suggest that hypo-osmoregulation is influenced by the relative proximities among a contingent of genes on Arctic charr linkage groups AC-4 and AC-12 that exhibit homologous affinities with a region on stickleback chromosome Ga-I. This supports the hypothesis that relative gene location along a chromosome is a property of the genetic architecture of hypo-osmoregulation. Evidence of non-random structure between hypo-osmoregulation candidate genes was found on AC-1/11 and AC-28, suggesting that interchromosomal rearrangements played a role in the evolution of hypo-osmoregulation in Arctic charr.
PubMed ID
25278466 View in PubMed
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The application of the intermediate 2-methyl-glyco-[2,1-d]-2-oxazolines for glycoside synthesis.

https://arctichealth.org/en/permalink/ahliterature10320
Source
Carbohydr Res. 2000 Dec 1;329(4):895-9
Publication Type
Article
Date
Dec-1-2000
Author
S S Pertel
V Y Chirva
A L Kadun
E S Kakayan
Author Affiliation
Department of Organic Chemistry, National Taurida University, Crimea, Ukraine. orgchem@ccssu.crimea.ua
Source
Carbohydr Res. 2000 Dec 1;329(4):895-9
Date
Dec-1-2000
Language
English
Publication Type
Article
Keywords
Alcohols - chemistry
Glycosides - chemical synthesis
Magnetic Resonance Spectroscopy
Molecular Structure
Oxazoles - chemistry
Salts - chemistry
Abstract
The synthesis of 2-acylamino-2-deoxysugars 1,2-trans-glycosides is described via the oxazolinium salt generated from an O,N-acetylated 1,2-cis-glycosyl halide of 2-amino-2-deoxysugar under the conditions of halide-anion catalysis. This salt was then interacted with alcohol to form the corresponding 1,2-trans-glycoside. A method for removing the generated hydrogen chloride is described. The conditions of this synthesis allow glycosides with acid-labile functional groups to be obtained. Suppression of the anomerisation of 1,2-trans-glycosides was achieved by the introduction of N,N'-dicyclohexyl urea into the reaction medium.
PubMed ID
11125834 View in PubMed
Less detail

[A rationale for the use of Carlsbad salt-enriched water in treating patients with biliary tract diseases at a sanatorium].

https://arctichealth.org/en/permalink/ahliterature229956
Source
Vopr Kurortol Fizioter Lech Fiz Kult. 1989 Nov-Dec;(6):50-1
Publication Type
Article

Are Early Somatic Embryos of the Norway Spruce (Picea abies (L.) Karst.) Organised?

https://arctichealth.org/en/permalink/ahliterature274028
Source
PLoS One. 2015;10(12):e0144093
Publication Type
Article
Date
2015
Author
Jiri Petrek
Ondrej Zitka
Vojtech Adam
Karel Bartusek
Naser A Anjum
Eduarda Pereira
Ladislav Havel
Rene Kizek
Source
PLoS One. 2015;10(12):e0144093
Date
2015
Language
English
Publication Type
Article
Keywords
Abies - drug effects - growth & development
Norway
Picea - drug effects - growth & development - metabolism
Plant Proteins - metabolism
Tetrazolium Salts - pharmacology
Abstract
Somatic embryogenesis in conifer species has great potential for the forestry industry. Hence, a number of methods have been developed for their efficient and rapid propagation through somatic embryogenesis. Although information is available regarding the previous process-mediated generation of embryogenic cells to form somatic embryos, there is a dearth of information in the literature on the detailed structure of these clusters.
The main aim of this study was to provide a more detailed structure of the embryogenic tissue clusters obtained through the in vitro propagation of the Norway spruce (Picea abies (L.) Karst.). We primarily focused on the growth of early somatic embryos (ESEs). The data on ESE growth suggested that there may be clear distinctions between their inner and outer regions. Therefore, we selected ESEs collected on the 56th day after sub-cultivation to dissect the homogeneity of the ESE clusters. Two colourimetric assays (acetocarmine and fluorescein diacetate/propidium iodide staining) and one metabolic assay based on the use of 2,3,5-triphenyltetrazolium chloride uncovered large differences in the metabolic activity inside the cluster. Next, we performed nuclear magnetic resonance measurements. The ESE cluster seemed to be compactly aggregated during the first four weeks of cultivation; thereafter, the difference between the 1H nuclei concentration in the inner and outer clusters was more evident. There were clear differences in the visual appearance of embryos from the outer and inner regions. Finally, a cluster was divided into six parts (three each from the inner and the outer regions of the embryo) to determine their growth and viability. The innermost embryos (centripetally towards the cluster centre) could grow after sub-cultivation but exhibited the slowest rate and required the longest time to reach the common growth rate. To confirm our hypothesis on the organisation of the ESE cluster, we investigated the effect of cluster orientation on the cultivation medium and the influence of the change of the cluster's three-dimensional orientation on its development. Maintaining the same position when transferring ESEs into new cultivation medium seemed to be necessary because changes in the orientation significantly affected ESE growth.
This work illustrated the possible inner organisation of ESEs. The outer layer of ESEs is formed by individual somatic embryos with high metabolic activity (and with high demands for nutrients, oxygen and water), while an embryonal group is directed outside of the ESE cluster. Somatic embryos with depressed metabolic activity were localised in the inner regions, where these embryonic tissues probably have a very important transport function.
Notes
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Cites: Anal Bioanal Chem. 2005 Oct;383(4):576-8616220262
Cites: Plant Cell Rep. 2006 Jan;24(12):691-816133349
Cites: J Exp Bot. 2013 Dec;64(18):5695-70524151302
Cites: J Exp Bot. 2014 Mar;65(5):1343-6024622953
Cites: PLoS One. 2015;10(10):e013995626445361
Cites: Biochim Biophys Acta. 2015 Apr;1849(4):385-40225038583
Cites: Biosci Biotechnol Biochem. 2015;79(5):725-3125640866
Cites: PLoS One. 2015;10(6):e012641426038822
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Cites: J Exp Bot. 2014 Jun;65(9):2319-3324713992
PubMed ID
26624287 View in PubMed
Less detail

Assembly of the Arctic flora: Highly parallel and recurrent patterns in sedges (Carex).

https://arctichealth.org/en/permalink/ahliterature300495
Source
Am J Bot. 2017 09; 104(9):1334-1343
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Date
09-2017
Author
Matthias H Hoffmann
Sebastian Gebauer
Torsten von Rozycki
Author Affiliation
Martin Luther University Halle-Wittenberg, Institute of Biology, Geobotany and Botanical Garden, Am Kirchtor 3 06108 Halle, Germany.
Source
Am J Bot. 2017 09; 104(9):1334-1343
Date
09-2017
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Keywords
Altitude
Arctic Regions
Carex Plant - genetics
Phylogeography
Salt Tolerance
Wetlands
Abstract
Understanding the origin of ecosystems and their changes through time is important. Two mutually contrasting types of grasslands existed in the Arctic: dry- and cold-adapted grasslands of the Pleistocene dominated by Poaceae species, and presently dominating graminoid grasslands composed of sedges and rushes. We studied the taxon recruitment of the Arctic flora for Carex, the most species-rich and widespread genus of the Arctic. In this study we explore the possible geographical and altitudinal origins of the species, their ecological provenance in terms of soil moisture and light requirements, and salt tolerance.
We addressed these questions in a phylogenetic context using the latest megaphylogeny of Carex comprising almost all Arctic species and about half of the genus' total species diversity. Ecological data were extracted from the literature and analyzed for each clade comprising Arctic species.
Arctic Carex species were observed in 48 independent lineages. Almost all areas north of the meridional zone of the Northern Hemisphere may have served as sources of Arctic lineages. Source areas are unrelated to the distribution within the Arctic. Arctic species evolved in lowland and high mountain clades; mostly in wet, rarely in dry adapted clades that occur principally in open conditions. Salt tolerant Arctic species occur in five clades.
Many independent lineages of different geographical areas and ecological backgrounds provided species for the northernmost ecosystem; clear main sources were not discernible. Carex shows the whole dynamic of ecosystem assembly from a seemingly simple immigration of preadapted species, evolution in geographical distant areas, to species radiations in the North.
PubMed ID
29885234 View in PubMed
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[Association of fatty acid composition of blood serum with bile lipid composition in cholelithiasis patients].

https://arctichealth.org/en/permalink/ahliterature158045
Source
Ter Arkh. 2008;80(2):71-5
Publication Type
Article
Date
2008
Author
V V Tsukanov
E Iu Kupershtein
Iu L Tonkikh
E P Bronnikova
Source
Ter Arkh. 2008;80(2):71-5
Date
2008
Language
Russian
Publication Type
Article
Keywords
Adult
Bile - chemistry
Bile Acids and Salts - analysis
Biological Markers - analysis - metabolism
Cholelithiasis - epidemiology - metabolism
Chromatography, Gas
Fatty Acids - blood
Female
Humans
Male
Middle Aged
Prevalence
Russia - epidemiology
Abstract
To examine correlations between bile lipid composition and fatty acid composition of blood serum in cholelithiasis patients.
Cholelithiasis prevalence in Khakasia Republic was studied in a clinico-epidemiological trial with participation of 1393 European people and 1060 mongoloid people--Khakasians. Bile lipids and serum fatty acids were measured.
Europeans had cholelithiasis in 7.3%, Khakasians--3.4% (p
PubMed ID
18372601 View in PubMed
Less detail

[A tip how to treat diarrhea caused by biliary acids].

https://arctichealth.org/en/permalink/ahliterature209588
Source
Duodecim. 1997;113(8):768
Publication Type
Article
Date
1997
Author
H J Järvinen
Author Affiliation
Department of Surgery, Helsinki University Central Hospital, Helsinki, Finland.
Source
Duodecim. 1997;113(8):768
Date
1997
Language
Finnish
Publication Type
Article
Keywords
Abdomen - surgery
Bile Acids and Salts
Cholestyramine Resin - administration & dosage
Diarrhea - drug therapy - etiology
Finland
Humans
Male
Middle Aged
Treatment Outcome
PubMed ID
11466878 View in PubMed
Less detail

Bacterial responses to fluctuations and extremes in temperature and brine salinity at the surface of Arctic winter sea ice.

https://arctichealth.org/en/permalink/ahliterature257926
Source
FEMS Microbiol Ecol. 2014 Aug;89(2):476-89
Publication Type
Article
Date
Aug-2014
Author
Marcela Ewert
Jody W Deming
Author Affiliation
School of Oceanography, University of Washington, Seattle, WA, USA.
Source
FEMS Microbiol Ecol. 2014 Aug;89(2):476-89
Date
Aug-2014
Language
English
Publication Type
Article
Keywords
Alaska
Arctic Regions
Cold Temperature
Freezing
Gammaproteobacteria - physiology
Ice Cover - microbiology
Salinity
Salt-Tolerance
Seasons
Seawater - chemistry - microbiology
Snow - microbiology
Abstract
Wintertime measurements near Barrow, Alaska, showed that bacteria near the surface of first-year sea ice and in overlying saline snow experience more extreme temperatures and salinities, and wider fluctuations in both parameters, than bacteria deeper in the ice. To examine impacts of such conditions on bacterial survival, two Arctic isolates with different environmental tolerances were subjected to winter-freezing conditions, with and without the presence of organic solutes involved in osmoprotection: proline, choline, or glycine betaine. Obligate psychrophile Colwellia psychrerythraea strain 34H suffered cell losses under all treatments, with maximal loss after 15-day exposure to temperatures fluctuating between -7 and -25 °C. Osmoprotectants significantly reduced the losses, implying that salinity rather than temperature extremes presents the greater stress for this organism. In contrast, psychrotolerant Psychrobacter sp. strain 7E underwent miniaturization and fragmentation under both fluctuating and stable-freezing conditions, with cell numbers increasing in most cases, implying a different survival strategy that may include enhanced dispersal. Thus, the composition and abundance of the bacterial community that survives in winter sea ice may depend on the extent to which overlying snow buffers against extreme temperature and salinity conditions and on the availability of solutes that mitigate osmotic shock, especially during melting.
PubMed ID
24903191 View in PubMed
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102 records – page 1 of 11.