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'Studies on the chemical and physical properties of some acetylenic and conjugated enynoic fatty esters'Alam, Mohammad Shahin. January 1999 (has links)
published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy
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The effects of cyclopropenoid fatty acids on structural components of microsomal membranesMorrissey, Michael Thomas 14 December 1982 (has links)
Studies were conducted to determine the effects of cyclopropenoid
fatty acids (CPFA) on the microsomal membrane of livers of rainbow
trout (Salmo gairdneri). Slab and tube gel electrophoresis of
microsomes from trout fed a CPFA diet (CPFA-microsomes) for varying
time periods showed a decrease in the number of protein bands resolved
in the high molecular weight region. This disappearance of
high molecular weight proteins was not due to increased proteolysis
in the CPFA-microsomes.
Antibodies against whole microsomal protein from livers of
trout fed 300 ppm CPFA were produced in rabbits. Microsomal proteins
were first separated by polyacrylamide gel electrophoresis
(PAGE), transferred to nitrocellulose sheets (NC) and analyzed by
the peroxidase-antiperoxidase (PAP) immunochemical staining procedure.
Immunoabsorption of antisera directed against CPFA-microsomes
by control-microsomes did not reveal any new proteins induced
by the CPFA diets. However, the intensity of PAP staining was much
greater in CPFA microsomes after immunoabsorption.
Hydrolysis of phospholipids in the microsomal membrane by
phospholipase A₂ failed to reveal any differences between control
and CPFA fed trout. Proteolysis of microsomal membrane proteins
had similar effects on NADPH cytochrome reductase and cytochrome
P-450 activity on fish fed the different diets. PAGE analysis of
these digests did show some differences in digested proteins between the control and CPFA group. These results may reflect a possible
change in orientation of microsomal membrane proteins brought
about by CPFA in the diet. Additional evidence for altered orientation
of proteins was found with PAGE analysis of trypsin-digested
microsomes. Moreover incubation of trypsin-digested microsomes
with antisera and stained with PAP showed that proteolytic attack
was different between control and CPFA microsomes. A final study
with incubation of transferred proteins from control and CPFA-microsomes
with antisera directed against purified cytochrome P-450
(P-450) and cytochrome P-448 (P-448) showed that CPFA had an effect
on the concentration of P-448 but not P-450. / Graduation date: 1983
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Plasma cholesterol levels, atherosclerosis and liver damage in rabbits fed cyclopropenoid fatty acidsFerguson, Thomas Lyle 01 April 1974 (has links)
In this five-week feeding study male New Zealand rabbits were
fed diets containing cyclopropene fatty acids (CPFA), diets containing
cholesterol, and diets with both CPFA and cholesterol added to test
the effect of CPFA on cholesterol metabolism and atherosclerosis
induction. When CPFA-fed animals were compared with control
animals, they tended to have higher plasma cholesterol levels, higher
liver cholesterol levels and a high incidence of aortic atherosclerosis.
Control animals had no atherosclerosis. A similar pattern was seen
when animals fed cholesterol were compared with those fed both
cholesterol and CPFA. Mean triglyceride levels were higher in
CPFA-fed rabbits than in controls.
A wide range of sensitivity to the CPFA was observed. Some
animals had plasma cholesterol levels eight to ten times normal after
three weeks of feeding; others showed only slight changes after five weeks. Histological examination of liver cells from CPFA-fed animals
showed evidence of alteration in cellular morphology and, in some
cases, extensive damage. In some liver cells of CPFA-fed rabbits,
subcellular organelles appear to be aligned in fiber-like structures.
The most extreme signs of toxicity were noted in livers of rabbits fed
CPFA and cholesterol.
After five weeks on experimental diets, adipose tissue of the
rabbits contained approximately 2% CPFA. Ratios of 16:0 to 16:1 and
18:0 to 18:1 fatty acids increased in liver lipid and erythrocyte ghost
lipid after CPFA feeding. Over the five-week study there were no
differences in rate of weight gain or in feed conversion ratios in
CPFA-fed animals. / Graduation date: 1974
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Alterations in growth, lipid metabolism and P:O ratios in mice fed Sterculia foetida oilLehman, Michael Wesley 28 June 1974 (has links)
Cyclopropenoid fatty acids (CPFA) are natural components of
cottonseed oil, a major food oil in the United States. The ability of
CPFA to cause abnormal biochemical and physiological effects when
fed to laboratory and farm animals has prompted an investigation of
their effects on mice.
Between 0.05 and 0.55% CPFA were fed as glycerines of
Sterculia foetida oil (SFO, containing 55% CPFA) to mice to determine
their effect on certain aspects of growth, lipid metabolism and
mitochondrial function.
One-half percent SFO fed to weanling mice caused a small
temporary decrease in growth rate when compared to controls. Many
mice fed 1% SFO stopped growing and died by the end of a 9-week
feeding trial. Mice fed less than 1% SFO, or 1% SFO for shorter
periods of time, showed increased liver-to-body-weight ratios, accumulation of CPFA in adipose tissue and increased ratios of
16:0/16:1, 18:0/18:1 and total saturated to unsaturated fatty acids in
liver and depot fat. Erythrocytes from CPFA-fed mice hemolyzed
more slowly than erythrocytes from control mice in isotonicnonelectrolytes,
implying an effect of CPFA on membrane lipid composition.
One-half percent SFO fed for 9 to 31 days inhibited almost
completely the incorporation of [¹⁴c] from labeled palmitate or
acetate into liver monounsaturated fatty acids. At the same time,
0.5% SFO retarded the incorporation of label from acetate into
¹⁴C₂ and total liver lipid, but stimulated twofold the incorporation
into liver sterols. The oxidation of labeled palmitate was also
reduced. CPFA caused lipid accumulation in livers.
P:0 ratios of liver mitochondria from mice fed 1% SFO for 6 to
15 days were 1.06- 1.45 while control P:0 ratios were 2.30-2.85.
The decrease was due to decreased phosphorylation, but increased
respiration. The relationship between the observed results and
membrane fatty acid composition was discussed. / Graduation date: 1975
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Glass capillary gas chromatographic analysis for trace amounts of cyclopropenoid fatty acidsRyan, Daberath 09 March 1987 (has links)
Dietary cyclopropenoid fatty acids (CPFA) have long
been known to cause pronounced physiological disorders in
both farm and laboratory animals. Past work has shown
CPFA to be a powerful promoter of carcinogenesis in trout,
rats and mice. Sterculic and malvalic acids (CPFA's) are
found in seed lipids of plants from the order Malvales.
Two members of this order are cotton and kapok, both of
which are used extensively as cooking oils for human
consumption.
Present chemical and instrumental methods of analysis
for CPFA are effective only at CPFA levels above 0.1%, and
accurate only at levels above 1%. A more sensitive method
of analysis was developed exploiting recent technological
advances in glass capillary gas chromatography (GCGC). By
the use of cold on-column injection, and positioning of
the column at the base of the detector flame, this method
eliminates two problem areas found in other GC methods.
The other common component involved in CPFA decomposition,
during GC analysis, is the column. Vitrious silica columns with an inert stationary phase, SE-30, were shown
to separate the highly reactive CPFA without
decomposition. Proof of stability during analysis was
obtained by changing the variables of relative time on
column and column temperature. This method not only
allows individual determination of sterculic and malvalic
acid concentrations, it is rapid, accurate (to the
70 parts per million range), and is superior to other
instrumental and chemical methods.
The CPFA concentration for okra, hollyhock, cheese
weed, seashore mallow, kapok, and white cap cottonseed oil
are as follows: 0.3% to 0.92%, 0.33%, 2.6%, 2.6%, 12.8%,
and 75ppm, respectively. The two different values for
okra were found because seeds from two different growing
seasons were analyzed. No CPFA could be detected in Diet
Imperial Margarine, raw cocoa beans, cocoa butter or
Lucca's winterized cottonseed oil. / Graduation date: 1987
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Alteration of certain physiological and biochemical parameters in livers of rainbow trout fed methyl sterculateStruthers, Barbara Oft 09 November 1973 (has links)
The cyclopropene fatty acids, sterculic and malvalic, occur
naturally in a major food lipid, cottonseed oil, and have been implicated
in several physiological disorders. Rainbow trout in this
study were fed semipurified diets containing 200 or 300 ppm methyl
sterculate, and the effects on hepatic lipid and glycogen levels,
lipid incorporation of radioactive phosphate and fatty acids, and
mitochondrial energy production were investigated.
Chronic ingestion of methyl sterculate caused numerous histological
changes and some necrosis in the liver. Glycogen accumulated
in irregular pockets, but the level in whole liver was not
increased over controls. Hepatic lipid accumulation was noted after
several weeks, reaching a level six times that of controls after six
months. Liver weight of the sterculate-fed fish decreased in proportion to body weight during the first three weeks on the sterculate
diet, but after three months became significantly greater than
controls.
Ingestion of 200 ppm methyl sterculate for two weeks by trout
caused reduced incorporation of both phosphate and fatty acids into
phospholipids. The major reductions were found in minor fractions.
Label incorporation into cardiolipin, important for mitochondrial
function, was reduced ten-fold by the dietary sterculate. Incorporation
into a minor unknown phospholipid which constituted less than
1% of total phospholipids was reduced as much as 135-fold in the
mitochondrial fraction. Incorporation of 1-¹⁴C-oleate into diglycerides
was also inhibited.
The major changes caused by methyl sterculate appear to occur
in mitochondria. Neither the level of cytochrome P⁴⁵⁰ nor the
activity of NADPH neotetrazolium reductase, both of which occur in
the endoplasmic reticulum, was altered. P/0 ratios and the ability
to oxidize oleic acid to CO₂ were curtailed after only two weeks on
a diet containing methyl sterculate. / Graduation date: 1974
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Derivatisation and characterisation of type II polyketide synthase acyl carrier proteinsByrom, Katherine Jane January 1998 (has links)
No description available.
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Characterisation of a human stearoyl CoA desaturase gene (SCD2)Dempsey, Kate E. January 2001 (has links)
No description available.
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Dietary manipulation of the fatty acid composition of sheep meatCooper, Sarah Louise January 2002 (has links)
No description available.
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The adaptive effects of acyl chain unsaturation on the physical properties of biological membranesLogue, James Andrew January 1996 (has links)
No description available.
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