Evaluation of the Wellspring Model for Improving Nursing Home Quality

Examines how successfully the Wellspring model improved the quality of care for residents of eleven nonprofit nursing homes in Wisconsin. Looks at staff turnover, and evaluates the impact on facilities, employees, residents, and cost

Polyunsaturated fatty acid biosynthesis is involved in phenylephrine-mediated calcium release in vascular smooth muscle cells

Stimulation of vascular smooth muscle (VSM) ?1-adrenoceptors induces myosin phosphorylation and vasoconstriction via mobilisation of intracellular calcium and production of specific eicosanoids. Polyunsaturated fatty acid (PUFA) biosynthesis in VSM cells is involved, although the precise mechanism is not known. To address this, we characterised PUFA biosynthesis in VSM cells and determined its role in intracellular calcium release and eicosanoid production. Murine VSM cells converted 18:2n-6 to longer chain PUFA including 22:5n-6. ?6 (D6d) and ?5 (D5d) desaturase, and elongase (Elovl) 5 were expressed. Elovl2 was not detected in human, mouse or rat VSM cells, or in rat or mouse aortae, but tit was not associated with hypermethylation of its promoter. D6d or D5d inhibition reduced 18:3n-6 and 20:4n-6 synthesis, respectively, and induced concentration-related decrease in phenylephrine-mediated calcium release, and in PGE2 and PGF2? secretion. Together these findings suggest that PUFA biosynthesis in VSM cells is involved in calcium release associated with vasoconstriction

The effect of fructose feeding on intestinal triacylglycerol production and de novo fatty acid synthesis in humans

A high fructose intake exacerbates postprandial plasma triacylglycerol (TAG) concentration, an independent risk factor for cardiovascular disease, although it is unclear whether this is due to increased production or impaired clearance of triacylglycerol (TAG)-rich lipoproteins. We determined the in vivo acute effect of fructose on postprandial intestinal and hepatic lipoprotein TAG kinetics and de novo lipogenesis (DNL). Five overweight men were studied twice, 4 weeks apart. They consumed hourly mixed-nutrient drinks that were high-fructose (30% energy) or low-fructose (<2% energy) for 11 hours. Oral 2H2O was administered to measure fasting and postprandial DNL. Postprandial chylomicron (CM)-TAG and very low-density lipoprotein (VLDL)-TAG kinetics were measured with an intravenous bolus of [2H5]-glycerol. CM and VLDL were separated by their apolipoprotein B content using antibodies. Plasma TAG (P<0.005) and VLDL-TAG (P=0.003) were greater, and CM-TAG production rate (PR, P=0.046) and CM-TAG fractional catabolic rate (FCR, P=0.073) lower when high-fructose was consumed, with no differences in VLDL-TAG kinetics. Insulin was lower (P=0.005) and apoB48 (P=0.039), apoB100 (P=0.013) and NEFA (P=0.013) were higher after high-fructose. Postprandial hepatic fractional DNL was higher than intestinal fractional DNL with high-fructose (P=0.043) and low-fructose (P=0.043). Fructose consumption had no effect on the rate of intestinal or hepatic DNL. We provide the first measurement of the rate of intestinal DNL in humans. Lower CM-TAG PR and CM-TAG FCR with high-fructose consumption suggests lower clearance of CM, rather than elevated production, may contribute to elevated plasma TAG, possibly due to lower insulin-mediated stimulation of lipoprotein lipase

Role of the enterocyte in fructose-induced hypertriglyceridaemia

Dietary fructose has been linked to an increased post-prandial triglyceride (TG) level; which is an established independent risk factor for cardiovascular disease. Although much research has focused on the effects of fructose consumption on liver-derived very-low density lipoprotein (VLDL); emerging evidence also suggests that fructose may raise post-prandial TG levels by affecting the metabolism of enterocytes of the small intestine. Enterocytes have become well recognised for their ability to transiently store lipids following a meal and to thus control post-prandial TG levels according to the rate of chylomicron (CM) lipoprotein synthesis and secretion. The influence of fructose consumption on several aspects of enterocyte lipid metabolism are discussed; including de novo lipogenesis; apolipoprotein B48 and CM-TG production; based on the findings of animal and human isotopic tracer studies. Methodological issues affecting the interpretation of fructose studies conducted to date are highlighted; including the accurate separation of CM and VLDL. Although the available evidence to date is limited; disruption of enterocyte lipid metabolism may make a meaningful contribution to the hypertriglyceridaemia often associated with fructose consumption

Sex differences in lipid and glucose kinetics after ingestion of an acute oral fructose load

The increase in VLDL TAG concentration after ingestion of a high-fructose diet is more pronounced in men than in pre-menopausal women. We hypothesised that this may be due to a lower fructose-induced stimulation of de novo lipogenesis (DNL) in pre-menopausal women. To evaluate this hypothesis, nine healthy male and nine healthy female subjects were studied after ingestion of oral loads of fructose enriched with 13C6 fructose. Incorporation of 13C into breath CO2, plasma glucose and plasma VLDL palmitate was monitored to evaluate total fructose oxidation, gluconeogenesis and hepatic DNL, respectively. Substrate oxidation was assessed by indirect calorimetry. After 13C fructose ingestion, 44·0 (sd 3·2)% of labelled carbons were recovered in plasma glucose in males v. 41·9 (sd 2·3)% in females (NS), and 42·9 (sd 3·7)% of labelled carbons were recovered in breath CO2 in males v. 43·0 (sd 4·5)% in females (NS), indicating similar gluconeogenesis from fructose and total fructose oxidation in males and females. The area under the curve for 13C VLDL palmitate tracer-to-tracee ratio was four times lower in females (P<0·05), indicating a lower DNL. Furthermore, lipid oxidation was significantly suppressed in males (by 16·4 (sd 5·2), P<0·05), but it was not suppressed in females (−1·3 (sd 4·7)%). These results support the hypothesis that females may be protected against fructose-induced hypertriglyceridaemia because of a lower stimulation of DNL and a lower suppression of lipid oxidatio

Dose dependent effects of fructose and glucose on de novo palmitate and glycerol synthesis in an enterocyte cell model

Scope: Fructose exacerbates post-prandial hypertriacylglycerolaemia. This may be partly due to increased enterocyte de novo lipogenesis (DNL). It is unknown whether this is concentration-dependent or whether fructose has a greater effect on lipid synthesis than glucose. The dose-dependent effects of fructose and glucose on DNL and de novo triacylglycerol (TAG)-glycerol synthesis were investigated in an enterocyte model, Caco-2 cells. Methods and results: Caco-2 cells were treated for 96h with 5mM, 25mM or 50mM fructose or glucose, or 12.5mM fructose/12.5mM glucose mix. DNL was measured following addition of [13C2]-acetate to apical media. In separate experiments, [13C6]-fructose and [13C6]-glucose were used to measure DNL and de novo TAG-glycerol synthesis. DNL from [13C2]-acetate was detected following all treatments, with greater amounts in intracellular than secreted (media) samples (all P <0.05). DNL from [13C6]-fructose and [13C6]-glucose was also measurable. Intracellular synthesis was concentration-dependent for both glucose and fructose tracers (P=0.003, P=0.034, respectively) and was higher with 25mM glucose than 25mM fructose (P=0.025). DNL from fructose and glucose was <1%, but up to 70% of de novo TAG-glycerol was synthesised from glucose or fructose. Conclusion: Fructose is not a major source of DNL in Caco-2 cells but contributes substantially to de novo TAG-glycerol synthesis

Femoral Adipose Tissue May Accumulate the Fat That Has Been Recycled as VLDL and Nonesterified Fatty Acids

OBJECTIVE: Gluteo-femoral, in contrast to abdominal, fat accumulation appears protective against diabetes and cardiovascular disease. Our objective was to test the hypothesis that this reflects differences in the ability of the two depots to sequester fatty acids, with gluteo-femoral fat acting as a longer-term "sink." RESEARCH DESIGN AND METHODS: A total of 12 healthy volunteers were studied after an overnight fast and after ingestion of a mixed meal. Blood samples were taken from veins draining subcutaneous femoral and abdominal fat and compared with arterialized blood samples. Stable isotope-labeled fatty acids were used to trace specific lipid fractions. In 36 subjects, adipose tissue blood flow in the two depots was monitored with (133)Xe. RESULTS: Blood flow increased in response to the meal in both depots, and these responses were correlated (r(s) = 0.44, P &lt; 0.01). Nonesterified fatty acid (NEFA) release was suppressed after the meal in both depots; it was lower in femoral fat than in abdominal fat (P &lt; 0.01). Plasma triacylglycerol (TG) extraction by femoral fat was also lower than that by abdominal fat (P = 0.05). Isotopic tracers showed that the difference was in chylomicron-TG extraction. VLDL-TG extraction and direct NEFA uptake were similar in the two depots. CONCLUSIONS: Femoral fat shows lower metabolic fluxes than subcutaneous abdominal fat, but differs in its relative preference for extracting fatty acids directly from the plasma NEFA and VLDL-TG pools compared with chylomicron-TG

NAFLD exacerbates the effect of dietary sugar on liver fat and development of an atherogenic lipoprotein phenotype

This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by Springer.${\bf Aims/hypothesis:}$ We aimed to test the hypothesis that the effects of dietary sugar on lipoprotein metabolism are influenced by non-alcoholic fatty liver disease (NAFLD). ${\bf Methods:}$ The effect of two 12 week, iso-energetic diets, high and low in non-milk extrinsic sugars (26% and 6% total energy), matched for macronutrient content, was examined in a randomised, cross-over study in men with NAFLD (n=11) and controls (n= 14). Lipoprotein kinetics and the sources of fatty acids for triacylglycerol (TAG) production were measured using stable isotope tracers. ${\bf Results:}$ Liver fat was higher after the high versus low-sugar diet in both groups (p<0.02), but men with NAFLD showed a relatively greater response than controls (p<0.05). After the high versus low-sugar diet, VLDL1-TAG production rate was higher in the controls (p <0.002) due to a greater contribution from splanchnic fatty acids (p<0.02) and de novo lipogenesis (p <0.002), whereas in NAFLD, VLDL2-TAG production rate was higher (p <0.05), due to a greater contribution from splanchnic fatty acids (p<0.02). There was no difference in the contribution of systemic NEFA to VLDL1 and VLDL2-TAG production rate between diets in either group. Intermediate density lipoprotein (IDL), LDL2 and LDL3-apolipoprotein B production rates and post-heparin hepatic lipase activity were all higher (p<0.05) on the high-sugar diet in NAFLD. ${\bf Conclusions:}$ A high sugar intake promoted a greater accumulation of liver fat in NAFLD than controls and increased VLDL-TAG production in both groups, due mainly to an increased contribution of fatty acids from splanchnic sources, which includes hepatic TAG storage pools. These effects may drive the formation of atherogenic lipoproteins.The work was supported by a UK government grant from the Biological Biotechnology Scientific Research Council (Grant no. BB/G009899/1); University of Surrey PhD scholarship for AM; Medical Research Council (body composition measurements) and infrastructure support from the National Institute of Health Research at the Cambridge Biomedical Research Centre

Fatty acid composition and metabolic partitioning of α-linolenic acid are contingent on life stage in human CD3+ T lymphocytes

IntroductionImmune function changes across the life course; the fetal immune system is characterised by tolerance while that of seniors is less able to respond effectively to antigens and is more pro-inflammatory than in younger adults. Lipids are involved centrally in immune function but there is limited information about how T cell lipid metabolism changes during the life course.Methods and ResultsWe investigated whether life stage alters fatty acid composition, lipid droplet content and α-linolenic acid (18:3ω-3) metabolism in human fetal CD3+ T lymphocytes and in CD3+ T lymphocytes from adults (median 41 years) and seniors (median 70 years). Quiescent fetal T cells had higher saturated (SFA), monounsaturated fatty acid (MUFA), and ω-6 polyunsaturated fatty acid (PUFA) contents than adults or seniors. Activation-induced changes in fatty acid composition differed between life stages. The principal metabolic fates of [13C]18:3ω-3 were constitutive hydroxyoctadecatrienoic acid synthesis and β-oxidation and carbon recycling into SFA and MUFA. These processes declined progressively across the life course. Longer chain ω-3 PUFA synthesis was a relatively minor metabolic fate of 18:3ω-3 at all life stages. Fetal and adult T lymphocytes had similar lipid droplet contents, which were lower than in T cells from seniors. Variation in the lipid droplet content of adult T cells accounted for 62% of the variation in mitogen-induced CD69 expression, but there was no significant relationship in fetal cells or lymphocytes from seniors.DiscussionTogether these findings show that fatty acid metabolism in human T lymphocytes changes across the life course in a manner that may facilitate the adaptation of immune function to different life stages