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[Cholesterol synthesis in the skin of rats with rickets]

https://arctichealth.org/en/permalink/ahliterature62496
Source
Ukr Biokhim Zh. 1976 Sep-Oct;48(5):645-9
Publication Type
Article
Author
V L Semenov
Z M Datsenko
Source
Ukr Biokhim Zh. 1976 Sep-Oct;48(5):645-9
Language
Ukrainian
Publication Type
Article
Keywords
Animals
Cholecalciferol - deficiency
Cholesterol - biosynthesis - radiation effects
Diet
English Abstract
Rats
Rickets - metabolism
Skin - analysis - metabolism - radiation effects
Sterols - analysis
Time Factors
Ultraviolet Rays
Vitamin D Deficiency - metabolism
Abstract
The rachitogenic diet causes an inhibition of cholesterol synthesis in rat skin. Intensity of 2-14S-acetate incorporation into cholesterol precursors (matastenol, lathosterol, 7-dehydrocholesterol) and cholesterol drops considerably. UV-irradiation of animals suffering from rachitis intensifies cholesterol synthesis in skin. Simulteneously an increase is detected in the metabolic fund of cholesterol synthesis precursors, including 7-dehydrocholesterol, which is necessary to form antirachitic compounds in the organism.
PubMed ID
191968 View in PubMed
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Climate impacts on human settlement and agricultural activities in northern Norway revealed through sediment biogeochemistry.

https://arctichealth.org/en/permalink/ahliterature118641
Source
Proc Natl Acad Sci U S A. 2012 Dec 11;109(50):20332-7
Publication Type
Article
Date
Dec-11-2012
Author
Robert M D'Anjou
Raymond S Bradley
Nicholas L Balascio
David B Finkelstein
Author Affiliation
Climate System Research Center, Department of Geosciences, University of Massachusetts, Amherst, MA 01003, USA. rdanjou@geo.umass.edu
Source
Proc Natl Acad Sci U S A. 2012 Dec 11;109(50):20332-7
Date
Dec-11-2012
Language
English
Publication Type
Article
Keywords
Agriculture - history
Animals
Archaeology
Climate Change - history
Environment
Feces - chemistry
Geologic Sediments - analysis
History, Ancient
Humans
Norway
Sterols - analysis
Abstract
Disentangling the effects of climate change and anthropogenic activities on the environment is a major challenge in paleoenvironmental research. Here, we used fecal sterols and other biogeochemical compounds in lake sediments from northern Norway to identify both natural and anthropogenic signals of environmental change during the late Holocene. The area was first occupied by humans and their grazing animals at ~2,250 ± 75 calendar years before 1950 AD (calendar years before present). The arrival of humans is indicated by an abrupt increase in coprostanol (and its epimer epicoprostanol) in the sediments and an associated increase in 5ß-stigmastanol (and 5ß-epistigmastanol), which resulted from human and animal feces washing into the lake. Human settlement was accompanied by an abrupt increase in landscape fires (indicated by the rise in pyrolytic polycyclic aromatic hydrocarbons) and a decline in woodland (registered by a change in n-alkane chain lengths from leaf waxes), accelerating a process that began earlier in the Holocene. Human activity and associated landscape changes in the region over the last two millennia were mainly driven by summer temperatures, as indicated by independent tree-ring reconstructions, although there were periods when socioeconomic factors played an equally important role. In this study, fecal sterols in lake sediments have been used to provide a record of human occupancy through time. This approach may be useful in many archeological studies, both to confirm the presence of humans and grazing animals, and to distinguish between anthropogenic and natural factors that have influenced the environment in the past.
Notes
Cites: Sci Total Environ. 2012 Jan 1;414:6-2122137478
Cites: Environ Int. 2002 Mar;27(8):647-5411934114
PubMed ID
23185025 View in PubMed
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Distinctive lipid composition of the copepod Limnocalanus macrurus with a high abundance of polyunsaturated fatty acids.

https://arctichealth.org/en/permalink/ahliterature264291
Source
Lipids. 2014 Sep;49(9):919-32
Publication Type
Article
Date
Sep-2014
Author
Minna Hiltunen
Ursula Strandberg
Markku Keinänen
Sami Taipale
Paula Kankaala
Source
Lipids. 2014 Sep;49(9):919-32
Date
Sep-2014
Language
English
Publication Type
Article
Keywords
Animals
Chromatography, Gas
Copepoda - chemistry - metabolism
Ecosystem
Esters - analysis
Fatty Acids - analysis - chemistry
Fatty Acids, Unsaturated - analysis
Finland
Lakes
Lipids - analysis - chemistry
Seasons
Sterols - analysis
Zooplankton
Abstract
We studied the copepod Limnocalanus macrurus for seasonal variation in the composition of fatty acids, wax esters and sterols in large boreal lakes, where it occurs as a glacial-relict. Vast wax ester reserves of Limnocalanus were accumulated in a period of only two months, and comprised mono- and polyunsaturated fatty acids (PUFA) and saturated fatty alcohols. In winter, the mobilization of wax esters was selective, and the proportion of long-chain polyunsaturated wax esters declined first. PUFA accounted for >50% of all fatty acids throughout the year reaching up to ca. 65% during late summer and fall. Long-chain PUFA 20:5n-3 and 22:6n-3 together comprised 17-40% of all fatty acids. The rarely reported C24 and C26 very-long-chain PUFA (VLC-PUFA) comprised 6.2 ± 3.4 % of all fatty acids in August and 2.1 ± 1.7% in September. The VLC-PUFA are presumably synthesized by Limnocalanus from shorter chain-length precursors because they were not found in the potential food sources. We hypothesize that these VLC-PUFA help Limnocalanus to maximize lipid reserves when food is abundant. Sterol content of Limnocalanus, consisting ca. 90% of cholesterol, did not show great seasonal variation. As a lipid-rich copepod with high abundance of PUFA, Limnocalanus is excellent quality food for fish. The VLC-PUFA were also detected in planktivorous fish, suggesting that these compounds can be used as a trophic marker indicating feeding on Limnocalanus.
PubMed ID
25092258 View in PubMed
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Metabolic epidemiology of colon cancer: dietary pattern and fecal sterol concentrations of three populations.

https://arctichealth.org/en/permalink/ahliterature26982
Source
Nutr Cancer. 1983;5(1):34-40
Publication Type
Article
Date
1983
Author
B S Reddy
G. Ekelund
M. Bohe
A. Engle
L. Domellof
Source
Nutr Cancer. 1983;5(1):34-40
Date
1983
Language
English
Publication Type
Article
Keywords
Adult
Bile Acids and Salts - analysis
Colonic Neoplasms - epidemiology
Comparative Study
Epidemiologic Methods
Feces - analysis
Female
Food Habits
Humans
Male
Middle Aged
New York City
Research Support, U.S. Gov't, P.H.S.
Sterols - analysis
Sweden
Abstract
The nutrient intake, fecal neutral sterol concentration, and bile acid concentration of populations with a varied risk for colon cancer development were investigated. High-risk populations in the metropolitan New York area and Malmo, Sweden, were compared with an intermediate-risk population in Umea, Sweden. The mean daily intake of protein and fat was comparable in all groups, but the total daily fiber intake was higher in Umea, as was the total daily stool output. There was no difference in the total fiber intake and stool output between Malmo and metropolitan New York. The fecal secondary bile acid concentration was lower in Umea than in the other two areas; no difference was observed between Malmo and metropolitan New York. These results suggest that high fiber intake may be considered protective against colon cancer even in a population with a high risk intake. A high dietary fiber intake may limit colon cancer risk by increasing stool bulk, and thus diluting and/or binding tumor promoters.
PubMed ID
6634431 View in PubMed
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