Dinka Rees - Academia.edu (original) (raw)

Papers by Dinka Rees

Research paper thumbnail of A randomised, double-blind, cross-over trial to evaluate bread, in which gluten has been pre-digested by prolyl endoprotease treatment, in subjects self-reporting benefits of adopting a gluten-free or low-gluten diet

British Journal of Nutrition, 2018

The aim of the present study was to determine if the enzyme Aspergillus niger prolyl endoprotease... more The aim of the present study was to determine if the enzyme Aspergillus niger prolyl endoprotease (ANPEP), which degrades the immunogenic proline-rich residues in gluten peptides, can be used in the development of new wheat products, suitable for gluten-sensitive (GS) individuals. We have carried out a double-blind, randomised, cross-over trial with two groups of adults; subjects, self-reporting benefits of adopting a gluten-free or low-gluten diet (GS, n 16) and a control non-GS group (n 12). For the trial, volunteers consumed four wheat breads: normal bread, bread treated with 0·8 or 1 % ANPEP and low-protein bread made from biscuit flour. Compared with controls, GS subjects had a favourable cardiovascular lipid profile – lower LDL (4·0 (sem 0·3) v. 2·8 (sem 0·2) mmol/l; P=0·008) and LDL:HDL ratio (3·2 (sem 0·4) v. 1·8 (sem 0·2); P=0·005) and modified haematological profile. The majority of the GS subjects followed a low-gluten lifestyle, which helps to reduce the gastrointestinal...

Research paper thumbnail of Dose-related effects of eicosapentaenoic acid on innate immune function in healthy humans: a comparison of young and older men

The American Journal of Clinical Nutrition, 2006

Background: Increasing intakes of long-chain nҀ3 polyunsaturated fatty acids (PUFAs) can decrease... more Background: Increasing intakes of long-chain nҀ3 polyunsaturated fatty acids (PUFAs) can decrease markers of immunity. However, dose-and age-related responses have not been identified. Objective: The objective was to determine the effects of different amounts of eicosapentaenoic acid (EPA) on innate immune outcomes in young and older males. Design: In a controlled, double-blind study, healthy young and older men consumed 1 of 4 supplements provided as capsules: placebo (corn oil) or different amounts of an oil providing 1.35, 2.7, or 4.05 g EPA/d for 12 wk. Blood samples were collected at baseline and after 12 wk. Results: EPA was incorporated in a linear dose-response fashion into plasma and mononuclear cell (MNC) phospholipids; incorporation was greater in the older men. EPA treatment did not alter neutrophil or monocyte phagocytosis, monocyte respiratory burst, or the production of inflammatory cytokines by MNCs in the young or older men. EPA treatment caused a dose-dependent decrease in neutrophil respiratory burst only in the older men. Increased incorporation of EPA into plasma or MNC phospholipids was associated with decreased production of prostaglandin E 2 by MNCs from both young and older men. Conclusions: Older subjects incorporate EPA into plasma and MNC phospholipids more readily than do younger subjects. Other than prostaglandin E 2 production, innate immune responses in young subjects are not affected by an EPA intake of ͨ4.05 g/d. Older subjects are more sensitive to the immunologic effects of EPA, and the neutrophil respiratory burst is lower at higher EPA intakes.

Research paper thumbnail of Regulation of adhesion molecule expression in human endothelial and smooth muscle cells by omega-3 fatty acids and conjugated linoleic acids: Involvement of the transcription factor NF-κB?

Prostaglandins, Leukotrienes and Essential Fatty Acids, 2008

We previously showed conjugated linoleic acids (CLA) inhibited TNF-a-induced monocyte (THP-1) adh... more We previously showed conjugated linoleic acids (CLA) inhibited TNF-a-induced monocyte (THP-1) adhesion to human umbilical vein endothelial cells (HUVEC) in vitro which involved an increase in platelet activating factor (PAF). Here we show adhesion molecule (ADM) regulation by fatty acids and the differing role of nuclear factor kappa B (NF-kB) activation in HUVEC and vascular smooth muscle cells (vSMC). CLA and omega-3 long-chain polyunsaturated fatty acids (PUFA) (FA) reduced TNF-áinduced expression of ADMs (intercellular adhesion molecule-1 (ICAM-1); vascular cell adhesion molecule-1 (VCAM-1) but not Eselectin) on HUVEC and vSMC to different extents depending on FA type and concentration, cell type and method of analysis. IkBá phosphorylation in HUVEC and vSMC and transient transfection with NF-kB-luciferase reporter plasmid (HUVEC only) indicated differential NF-kB involvement during FA modulation (cis-9, trans-11; trans-10, cis-12 and a 50:50 mix of both CLA isomers; eicosapentaenoic acid (EPA); docosahexaenoic acid (DHA)). TNF-a-induced ADM expression in both cell types by 2-10fold. In HUVEC, CLA t10, c12 and CLA mix (50:50 mixture of CLA c9, t11 and t10, c12) and EPA and DHA reduced ICAM-1 expression (15-35%) at 12.5, 25 and/or 50 mM. VCAM-1 expression was reduced by 25 mM t10, c12 isomer and mix; omega-3 PUFA and other concentrations of CLA and TNF-a-induced E-selectin expression were unaffected. TNFa-induced inhibitor kappa B (IkB) phosphorylation was biphasic peaking at 5 min in both cell types and 60 and 120 min in HUVEC and SMC, respectively. IkBa phosphorylation and NF-kB activity was reduced (29% and 30%, respectively) by 25 mM CLA mix. n-3 PUFA did not reduce IkBa phosphorylation or NF-kB activity but reduced ADM expression. We show that n-3 PUFA and CLA reduce expression of ADM on HUVEC and vSMC. This reflected reduced adherence of monocytes to HUVEC previously reported by our group. Reduction of ICAM-1 and VCAM-1 protein expression by n-3 PUFA was less dependent on the NF-kB pathway than reduction by CLA which reflected the parallel attenuation of NF-kB activity. This indicated involvement of other transcription factors (i.e. AP-1) in the FA regulation of ADM expression and has, to our knowledge, not been previously reported.

Research paper thumbnail of Age-related increases in circulating inflammatory markers in men are independent of BMI, blood pressure and blood lipid concentrations

Atherosclerosis, 2008

Objective: To examine whether age-related increase in concentrations of circulating inflammatory ... more Objective: To examine whether age-related increase in concentrations of circulating inflammatory mediators is due to concurrent increases in cardiovascular risk factors or is independent of these. Methods and results: Cytokines (IL-6, IL-18), chemokines (6Ckine, MCP-1, IP-10), soluble adhesion molecules (sICAM-1, sVCAM-1, sE-selectin) and adipokines (adiponectin) were measured in the plasma of healthy male subjects aged 18-84 years (n = 162). These were related to known cardiovascular risk factors (age, BMI, systolic and diastolic blood pressure, plasma total cholesterol, LDL cholesterol, HDL cholesterol and triacylglycerol concentrations) in order to identify significant associations. Plasma concentrations of sVCAM-1, sE-selectin, IL-6, IL-18, MCP-1, 6Ckine, IP-10 and adiponectin, but not sICAM-1, were significantly positively correlated with age, as well as with several other cardiovascular risk factors. The correlations with other risk factors disappeared when age was controlled for. In contrast, the correlations with age remained significant for sVCAM-1, IL-6, MCP-1, 6Ckine and IP-10 when other cardiovascular risk factors were controlled for. Conclusions: Plasma concentrations of some inflammatory markers (sVCAM-1, IL-6, MCP-1, 6Ckine, IP-10) are positively correlated with age, independent of other cardiovascular risk factors. This suggests that age-related inflammation may not be driven by recognised risk factors.

Research paper thumbnail of Age- and dose-dependent effects of an eicosapentaenoic acid-rich oil on cardiovascular risk factors in healthy male subjects

Atherosclerosis, 2007

Supplementation with fish oils, rich in n − 3 polyunsaturated fatty acids, modifies cardiovascula... more Supplementation with fish oils, rich in n − 3 polyunsaturated fatty acids, modifies cardiovascular risk factors. However, dose-response relationships are poorly defined and whether similar effects are seen in young and older subjects is not known. This study determined the effect of supplementing the diet of young and older male subjects with different amounts of an eicosapentaenoic acid (EPA)-rich oil. Healthy young (18-42 years) and older (53-70 years) males were randomized to placebo or 1.35, 2.7 or 4.05 g EPA/day for 12 weeks. There was no effect of EPA on blood pressure or on plasma total, LDL or HDL cholesterol. EPA lowered plasma triacylglycerols, with the maximal effect at the lowest dose. Plasma lipoperoxides decreased in all groups. EPA decreased the lag time of copper-induced lipoprotein peroxidation and the ratio of reduced to total glutathione in the older subjects. The highest dose of EPA increased soluble E-selectin in young subjects, while increasing EPA tended to decrease soluble intercellular adhesion molecule 1 in young and older subjects. Young and older males will gain cardiovascular benefit from increased intake of EPA. Young males are unlikely to suffer adverse consequences from high EPA intake, whereas older males may have an increased risk of lipoprotein peroxidation.

Research paper thumbnail of A randomised, double-blind, cross-over trial to evaluate bread, in which gluten has been pre-digested by prolyl endoprotease treatment, in subjects self-reporting benefits of adopting a gluten-free or low-gluten diet

British Journal of Nutrition, 2018

The aim of the present study was to determine if the enzyme Aspergillus niger prolyl endoprotease... more The aim of the present study was to determine if the enzyme Aspergillus niger prolyl endoprotease (ANPEP), which degrades the immunogenic proline-rich residues in gluten peptides, can be used in the development of new wheat products, suitable for gluten-sensitive (GS) individuals. We have carried out a double-blind, randomised, cross-over trial with two groups of adults; subjects, self-reporting benefits of adopting a gluten-free or low-gluten diet (GS, n 16) and a control non-GS group (n 12). For the trial, volunteers consumed four wheat breads: normal bread, bread treated with 0·8 or 1 % ANPEP and low-protein bread made from biscuit flour. Compared with controls, GS subjects had a favourable cardiovascular lipid profile – lower LDL (4·0 (sem 0·3) v. 2·8 (sem 0·2) mmol/l; P=0·008) and LDL:HDL ratio (3·2 (sem 0·4) v. 1·8 (sem 0·2); P=0·005) and modified haematological profile. The majority of the GS subjects followed a low-gluten lifestyle, which helps to reduce the gastrointestinal...

Research paper thumbnail of Dose-related effects of eicosapentaenoic acid on innate immune function in healthy humans: a comparison of young and older men

The American Journal of Clinical Nutrition, 2006

Background: Increasing intakes of long-chain nҀ3 polyunsaturated fatty acids (PUFAs) can decrease... more Background: Increasing intakes of long-chain nҀ3 polyunsaturated fatty acids (PUFAs) can decrease markers of immunity. However, dose-and age-related responses have not been identified. Objective: The objective was to determine the effects of different amounts of eicosapentaenoic acid (EPA) on innate immune outcomes in young and older males. Design: In a controlled, double-blind study, healthy young and older men consumed 1 of 4 supplements provided as capsules: placebo (corn oil) or different amounts of an oil providing 1.35, 2.7, or 4.05 g EPA/d for 12 wk. Blood samples were collected at baseline and after 12 wk. Results: EPA was incorporated in a linear dose-response fashion into plasma and mononuclear cell (MNC) phospholipids; incorporation was greater in the older men. EPA treatment did not alter neutrophil or monocyte phagocytosis, monocyte respiratory burst, or the production of inflammatory cytokines by MNCs in the young or older men. EPA treatment caused a dose-dependent decrease in neutrophil respiratory burst only in the older men. Increased incorporation of EPA into plasma or MNC phospholipids was associated with decreased production of prostaglandin E 2 by MNCs from both young and older men. Conclusions: Older subjects incorporate EPA into plasma and MNC phospholipids more readily than do younger subjects. Other than prostaglandin E 2 production, innate immune responses in young subjects are not affected by an EPA intake of ͨ4.05 g/d. Older subjects are more sensitive to the immunologic effects of EPA, and the neutrophil respiratory burst is lower at higher EPA intakes.

Research paper thumbnail of Regulation of adhesion molecule expression in human endothelial and smooth muscle cells by omega-3 fatty acids and conjugated linoleic acids: Involvement of the transcription factor NF-κB?

Prostaglandins, Leukotrienes and Essential Fatty Acids, 2008

We previously showed conjugated linoleic acids (CLA) inhibited TNF-a-induced monocyte (THP-1) adh... more We previously showed conjugated linoleic acids (CLA) inhibited TNF-a-induced monocyte (THP-1) adhesion to human umbilical vein endothelial cells (HUVEC) in vitro which involved an increase in platelet activating factor (PAF). Here we show adhesion molecule (ADM) regulation by fatty acids and the differing role of nuclear factor kappa B (NF-kB) activation in HUVEC and vascular smooth muscle cells (vSMC). CLA and omega-3 long-chain polyunsaturated fatty acids (PUFA) (FA) reduced TNF-áinduced expression of ADMs (intercellular adhesion molecule-1 (ICAM-1); vascular cell adhesion molecule-1 (VCAM-1) but not Eselectin) on HUVEC and vSMC to different extents depending on FA type and concentration, cell type and method of analysis. IkBá phosphorylation in HUVEC and vSMC and transient transfection with NF-kB-luciferase reporter plasmid (HUVEC only) indicated differential NF-kB involvement during FA modulation (cis-9, trans-11; trans-10, cis-12 and a 50:50 mix of both CLA isomers; eicosapentaenoic acid (EPA); docosahexaenoic acid (DHA)). TNF-a-induced ADM expression in both cell types by 2-10fold. In HUVEC, CLA t10, c12 and CLA mix (50:50 mixture of CLA c9, t11 and t10, c12) and EPA and DHA reduced ICAM-1 expression (15-35%) at 12.5, 25 and/or 50 mM. VCAM-1 expression was reduced by 25 mM t10, c12 isomer and mix; omega-3 PUFA and other concentrations of CLA and TNF-a-induced E-selectin expression were unaffected. TNFa-induced inhibitor kappa B (IkB) phosphorylation was biphasic peaking at 5 min in both cell types and 60 and 120 min in HUVEC and SMC, respectively. IkBa phosphorylation and NF-kB activity was reduced (29% and 30%, respectively) by 25 mM CLA mix. n-3 PUFA did not reduce IkBa phosphorylation or NF-kB activity but reduced ADM expression. We show that n-3 PUFA and CLA reduce expression of ADM on HUVEC and vSMC. This reflected reduced adherence of monocytes to HUVEC previously reported by our group. Reduction of ICAM-1 and VCAM-1 protein expression by n-3 PUFA was less dependent on the NF-kB pathway than reduction by CLA which reflected the parallel attenuation of NF-kB activity. This indicated involvement of other transcription factors (i.e. AP-1) in the FA regulation of ADM expression and has, to our knowledge, not been previously reported.

Research paper thumbnail of Age-related increases in circulating inflammatory markers in men are independent of BMI, blood pressure and blood lipid concentrations

Atherosclerosis, 2008

Objective: To examine whether age-related increase in concentrations of circulating inflammatory ... more Objective: To examine whether age-related increase in concentrations of circulating inflammatory mediators is due to concurrent increases in cardiovascular risk factors or is independent of these. Methods and results: Cytokines (IL-6, IL-18), chemokines (6Ckine, MCP-1, IP-10), soluble adhesion molecules (sICAM-1, sVCAM-1, sE-selectin) and adipokines (adiponectin) were measured in the plasma of healthy male subjects aged 18-84 years (n = 162). These were related to known cardiovascular risk factors (age, BMI, systolic and diastolic blood pressure, plasma total cholesterol, LDL cholesterol, HDL cholesterol and triacylglycerol concentrations) in order to identify significant associations. Plasma concentrations of sVCAM-1, sE-selectin, IL-6, IL-18, MCP-1, 6Ckine, IP-10 and adiponectin, but not sICAM-1, were significantly positively correlated with age, as well as with several other cardiovascular risk factors. The correlations with other risk factors disappeared when age was controlled for. In contrast, the correlations with age remained significant for sVCAM-1, IL-6, MCP-1, 6Ckine and IP-10 when other cardiovascular risk factors were controlled for. Conclusions: Plasma concentrations of some inflammatory markers (sVCAM-1, IL-6, MCP-1, 6Ckine, IP-10) are positively correlated with age, independent of other cardiovascular risk factors. This suggests that age-related inflammation may not be driven by recognised risk factors.

Research paper thumbnail of Age- and dose-dependent effects of an eicosapentaenoic acid-rich oil on cardiovascular risk factors in healthy male subjects

Atherosclerosis, 2007

Supplementation with fish oils, rich in n − 3 polyunsaturated fatty acids, modifies cardiovascula... more Supplementation with fish oils, rich in n − 3 polyunsaturated fatty acids, modifies cardiovascular risk factors. However, dose-response relationships are poorly defined and whether similar effects are seen in young and older subjects is not known. This study determined the effect of supplementing the diet of young and older male subjects with different amounts of an eicosapentaenoic acid (EPA)-rich oil. Healthy young (18-42 years) and older (53-70 years) males were randomized to placebo or 1.35, 2.7 or 4.05 g EPA/day for 12 weeks. There was no effect of EPA on blood pressure or on plasma total, LDL or HDL cholesterol. EPA lowered plasma triacylglycerols, with the maximal effect at the lowest dose. Plasma lipoperoxides decreased in all groups. EPA decreased the lag time of copper-induced lipoprotein peroxidation and the ratio of reduced to total glutathione in the older subjects. The highest dose of EPA increased soluble E-selectin in young subjects, while increasing EPA tended to decrease soluble intercellular adhesion molecule 1 in young and older subjects. Young and older males will gain cardiovascular benefit from increased intake of EPA. Young males are unlikely to suffer adverse consequences from high EPA intake, whereas older males may have an increased risk of lipoprotein peroxidation.