An investigation of recommended serve food portions and attaining energy and protein requirements in older adults living in residential care.

BACKGROUND: Ageing populations show a propensity for reduced food intake, which impacts nutritional adequacy. Nutrition guidelines for residential care homes (RCHs) are currently based on serve size of core food groups and do not consider nutrient density. The present study aimed to investigate the weight of foods served/consumed compared to recommended serve sizes and to compare energy and protein intake with individual requirements. METHODS: This was an observational study of older adults living in four RCHs. Dietary intake was estimated through the difference between weighed reference meals and a single, double-weighed 24-h food plate waste collected from each participant. FoodWorks9® (Xyris® Software, Brisbane, Australia) was used to calculate energy, protein and serves of core food groups from food intake and the menu provided to recommended serve sizes. Individual intake was compared with nutrition guidelines and estimated energy and protein requirements. RESULTS: Across 420 participants, 9.8% completed a main meal (lunch or dinner). The servings provided [248 g; interquartile range (IQR) = 206-290 g] were less than the recommended servings for a main meal (306 g = protein/starch/two vegetables), with 157 g (IQR = 109-221 g) consumed. The menu provided for minimum serves of all core food groups except for dairy. Median energy intake (n = 389) (5272 kJ day-1 , IQR = 4229-6720 kJ) and protein intake (47.3 g day-1 , IQR = 35.9-60.8 g) were less than estimated requirements (8181 kJ day-1 , IQR = 7300-9338 kJ day-1 ; 76.7 g day-1 , IQR = 66.7-90.8 g). CONCLUSIONS: Nutritional needs were not met in this cohort. The findings of the present study highlight the need for smaller, nutrient-dense meals and revised menu standards to ensure nutritional adequacy in this vulnerable population.

The impact of multicomponent weight management interventions on quality of life in adolescents affected by overweight or obesity: a meta-analysis of randomized controlled trials.

Adolescents affected by overweight or obesity report similar quality of life to adolescents with cancer. While weight management is important for physiological outcomes, it is unclear whether weight management improves quality of life in this age group. This meta-analysis assessed the impact of multicomponent weight management interventions on quality of life in adolescents affected by overweight or obesity. Ovid PsycINFO, Ovid Medline, Ovid Embase, Cochrane Library, Scopus and CINAHL Plus databases were searched up to July 2017. Eight eligible studies were randomized controlled trials of multicomponent weight management interventions for adolescents (10 to 19 years) affected by overweight or obesity, with quality of life and weight measurements. Meta-analyses determined a positive effect on quality of life (mean difference 0.20 [0.11, 0.29]; p < 0.01) and weight (mean difference 0.30 [0.12, 0.47]; p < 0.01) following intervention. There was no correlation between weight loss and improvements in quality of life (R2  = 0.103). Rather than weight loss, intervention factors such as parental involvement, group settings and a focus on psychosocial well-being appeared linked to improvements in quality of life. The reduced quality of life reported by this group may be due to social consequences of obesity, rather than actual weight.

Indices of adiposity as predictors of cardiometabolic risk and inflammation in young adults.

BACKGROUND: Studies investigating obesity and cardiometabolic risk have focused on 'at-risk' populations and methodological inconsistencies have produced equivocal findings. The present cross-sectional study investigated indices of body composition as predictors of cardiometabolic risk and their relationship with inflammation in apparently healthy young adults. METHODS: A fasting blood sample was taken from consenting adults (160 males, 32 females, aged 18-40 years) for assessment of cardiometabolic risk markers (blood pressure, lipid profiles and insulin resistance) and inflammatory markers (C-reactive protein, tumour necrosis factor-α, interleukin-6, interleukin-10 and adiponectin). Together with anthropometry, fat mass (FM) and fat-free mass (FFM) were determined by dual-energy X-ray absorptiometry. FM was expressed in absolute terms (kg), as well as relative to total body weight (%), height [FM index (FMI, kg m(-2) )] and FFM (FM : FFM,%). RESULTS: Although anthropometric indices were associated with most cardiometabolic risk markers, the strongest relationship was observed with FMI. Relative to having a low cardiometabolic risk (≤2 markers above clinically relevant cut-offs), each kg m(-2) increase in FMI, increased the likelihood of having an increased cardiometabolic risk by 29% (odds ratio = 1.29; 95% confidence interval = 1.12-1.49). Inflammatory markers were not associated with body composition or cardiometabolic risk. CONCLUSIONS: FMI was the strongest predictor of overall cardiometabolic risk but not inflammation per se. However, anthropometric indices, such as body mass index and waist-to-height ratio, remain valuable surrogate measures of adiposity in this group, particularly when risk markers are considered independently.

Systematic review and meta-analysis of the effect of meal intake on postprandial appetite-related gastrointestinal hormones in obese children.

UNLABELLED: Understanding the physiological response to meal intake, of gut-derived appetite and satiety hormone signals, in obese compared with healthy-weight children may assist with informing strategies to help curtail the obesity epidemic. A systematic review and meta-analysis of studies investigating the acute postprandial response of gastrointestinal appetite hormones to meal intake in obese children was undertaken. Systematic searches of databases EMBASE, CINAHL Plus, OVID Medline and the Cochrane Library were performed. INCLUSION CRITERIA: a randomised controlled trial or experimental cross-sectional study following an acute test meal protocol with pre- and postprandial analysis of plasma or serum gastrointestinal hormone concentrations. Database searching retrieved 1001 papers for review. Nine studies met the inclusion criteria, collectively reporting on six appetite hormones yielding a total of 32 test meal-hormone comparisons. Meta-analyses compared the pooled estimate of the mean difference of the postprandial change in total ghrelin and total peptide YY (PYY). Obese compared with healthy-weight children had an attenuated change in ghrelin at 60 min (N=5 studies; n=129 participants) and 120 min postprandial (N=4 studies; n=100 participants) (P<0.05 for both time points). Obese compared with healthy-weight children also had an attenuated PYY response at 60 min (N=5 studies; n=128 participants) and 120 min postprandial (N=4 studies; n=100 participants). Insufficient studies reported on the postprandial time course of other appetite-related hormones, precluding a meta-analysis. Limited evidence notwithstanding, these findings indicate that PYY and ghrelin responses to a meal may be altered in obese children. This review has also identified a major gap in knowledge of hormonal appetite responses in childhood obesity. More comprehensive investigations of the homoeostatic regulation of gut-derived appetite and satiety hormone signals with behavioural and clinical outcomes are warranted to understand if there are consequences of these differences.

Active surveillance: does serial prostate biopsy increase histological inflammation?

BACKGROUND: Active surveillance (AS) is an appropriate management strategy for men with low-risk prostate cancer. Most protocols recommend repeated prostate biopsy every 12-24 months. The purpose of this paper is to describe histological inflammation patterns in men on AS who underwent serial prostate biopsy for disease monitoring. METHODS: We reviewed records of men on AS from January 1999 through February 2011 who had a diagnostic plus ≥1 repeat transrectal ultrasound-guided biopsies performed at our institution. The type and degree of inflammatory infiltrate were grossly reviewed and scored for each patient's biopsy by a single pathologist. Relationship of inflammation severity and number of serial biopsies was assessed using a repeated measures mixed model. Unpaired t-test and χ(2)-square analysis assessed variance in degree of inflammation and location of inflammation relative to cancer grade progression defined as Gleason sum increase. RESULTS: Fifty-six men met study inclusion criteria. Mean age was 62.1 (6.5) years, 71% were stage cT1c, 79% had a PSA level <10 ng ml(-1), and 98% had diagnostic Gleason sum ≤6. A small, statistically significant increase in maximum chronic inflammation (CI) scores with greater number of repeat biopsies was observed. CI scores were not associated with number of biopsies based on upgrade status. The main limitation to our study is our small sample size. Potential unmeasured confounders, such as unreported antibiotic use or symptomatic prostatitis, may have also affected our findings. CONCLUSIONS: In this pilot study of 56 men on AS for localized prostate cancer, degree of chronic histological inflammation increased with greater number of prostate biopsies, but was not associated with subsequent risk of grade progression.

Red meat from animals offered a grass diet increases plasma and platelet n-3 PUFA in healthy consumers.

Red meat from grass-fed animals, compared with concentrate-fed animals, contains increased concentrations of long-chain (LC) n-3 PUFA. However, the effects of red meat consumption from grass-fed animals on consumer blood concentrations of LC n-3 PUFA are unknown. The aim of the present study was to compare the effects on plasma and platelet LC n-3 PUFA status of consuming red meat produced from either grass-fed animals or concentrate-fed animals. A randomised, double-blinded, dietary intervention study was carried out for 4 weeks on healthy subjects who replaced their habitual red meat intake with three portions per week of red meat (beef and lamb) from animals offered a finishing diet of either grass or concentrate (n 20 consumers). Plasma and platelet fatty acid composition, dietary intake, blood pressure, and serum lipids and lipoproteins were analysed at baseline and post-intervention. Dietary intakes of total n-3 PUFA, as well as plasma and platelet concentrations of LC n-3 PUFA, were significantly higher in those subjects who consumed red meat from grass-fed animals compared with those who consumed red meat from concentrate-fed animals (P < 0·05). No significant differences in concentrations of serum cholesterol, TAG or blood pressure were observed between groups. Consuming red meat from grass-fed animals compared with concentrate-fed animals as part of the habitual diet can significantly increase consumer plasma and platelet LC n-3 PUFA status. As a result, red meat from grass-fed animals may contribute to dietary intakes of LC n-3 PUFA in populations where red meat is habitually consumed.

Comparison of the effects of four commercially available weight-loss programmes on lipid-based cardiovascular risk factors.

OBJECTIVE: To investigate the relative efficacy of four popular weight-loss programmes on plasma lipids and lipoproteins as measures of CVD risk. DESIGN: A multi-centred, randomised, controlled trial of four diets - Dr Atkins' New Diet Revolution, The Slim-Fast Plan, Weight Watchers Pure Points programme and Rosemary Conley's 'Eat yourself Slim' Diet and Fitness Plan - against a control diet, in parallel for 6 months. SETTING AND SUBJECTS: The trial was conducted at five universities across the UK (Surrey, Nottingham, Ulster (Coleraine), Bristol and Edinburgh (Queen Margaret University College)) and involved the participation of 300 overweight and obese males and females aged 21-60 years in a community setting. RESULTS: Significant weight loss was achieved by all dieting groups (5-9 kg at 6 months) but no significant difference was observed between diets at 6 months. The Weight Watchers and Rosemary Conley (low-fat) diets were followed by significant reductions in plasma LDL cholesterol (both -12.2 % after 6 months, P < 0.01), whereas the Atkins (low-carbohydrate) and Weight Watchers diets were followed by marked reductions in plasma TAG (-38.2 % and -22.6 % at 6 months respectively, P < 0.01). These latter two diets were associated with an increase in LDL particle size, a change that has been linked to reduced CVD risk. CONCLUSIONS: Overall, these results demonstrate the favourable effects of weight loss on lipid-mediated CVD risk factors that can be achieved through commercially available weight-loss programmes. No detrimental effects on lipid-based CVD risk factors were observed in participants consuming a low-carbohydrate diet.

Habitual fish consumption does not prevent a decrease in LCPUFA status in pregnant women (the Seychelles Child Development Nutrition Study).

Information on the status of long-chain polyunsaturated fatty acids (LCPUFAs) in pregnancy and breast milk in very high fish-eating populations is limited. The aim of this study was to examine dietary intake and changes in fatty acid status in a population of pregnant women in the Republic of Seychelles. Serum docosahexaenoic acid (DHA) decreased significantly between 28-week gestation and delivery (n=196). DHA status did not correlate significantly with length of gestation and was not associated with self-reported fish intake, which was high at 527 g/week. In breast milk, the ratio of DHA to arachidonic acid (AA) was consistent with those observed in other high fish-eating populations. Overall the data suggest that high exposure to LCPUFAs from habitual fish consumption does not prevent the documented decrease in LCPUFA status in pregnancy that occurs as a result of foetal accretion in the third trimester of pregnancy.

Assessment of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D3 concentrations in male and female multiple sclerosis patients and control volunteers.

Populations with insufficient ultraviolet exposure and who consume diets low in vitamin D have low vitamin D status (plasma 25-hydroxyvitamin D (25(OH)D) concentrations) and a reported higher incidence of multiple sclerosis (MS). The active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), is an effective anti-inflammatory molecule. No research to date has assessed 1,25(OH)2D3 concentrations in individuals with MS. In this study, plasma concentrations of 25(OH)D, 1,25(OH)2D3 and parathyroid hormone (PTH) were measured in 29 individuals with MS and 22 age- and sex-matched control volunteers. There were no significant differences in plasma PTH, 25(OH)D and 1,25(OH)2D3 concentrations between individuals with MS and control volunteers. Women with MS had significantly higher 25(OH)D and 1,25(OH)2D3 concentrations than men with MS (79.1+/-45.4 versus 50.2+/-15.3 nmol/L, P=0.019 and 103.8+/-36.8 versus 70.4+/-28.7 pmol/L, P=0.019, respectively). There was a significant positive correlation between 25(OH)D and 1,25(OH)2D3 concentrations in all subjects (r=0.564, P=0.000), but secondary analysis revealed that the correlation was driven by women with MS (r=0.677, P=0.001). Significant sex differences in vitamin D metabolism were observed and were most marked in individuals with MS, suggesting that vitamin D requirements may differ between the sexes, as well as by underlying disease state.

Effect of vitamin D supplementation on vitamin D status and bone turnover markers in young adults.

OBJECTIVE: To assess the vitamin D status of healthy young people living in Northern Ireland and the effect of vitamin D supplementation on vitamin D status and bone turnover. DESIGN: Double-blinded randomised controlled intervention study. SETTING: University of Ulster, Coleraine, Northern Ireland. SUBJECTS: In total, 30 apparently healthy students (15 male and 15 female subjects), aged 18-27 years, were recruited from the university, with 27 completing the intervention. INTERVENTIONS: Subjects were randomly assigned, to receive either 15 microg (600 IU) vitamin D(3) and 1,500 mg calcium/day (vitamin D group), or 1,500 mg calcium/day (control group) for 8 weeks between January and March. Vitamin D status, bone turnover markers, serum calcium and parathyroid hormone concentrations were measured at baseline and post intervention. RESULTS: At baseline, vitamin D status was low in both the vitamin D group (47.9 (s.d. 16.0)) and the control group (55.5 (s.d. 18.6) nmol/l 25(OH)D). Post intervention vitamin D status was significantly higher in the vitamin D-treated group (86.5 (s.d. 24.5)) compared to the control group (48.3 (s.d. 16.8) nmol/l) (P<0.0001). There was no significant effect of supplementation on bone turnover markers or PTH concentrations. CONCLUSIONS: This study suggests that young adults in Northern Ireland do not consume an adequate daily dietary intake of vitamin D to maintain plasma vitamin D concentrations in the wintertime. A daily supplement of 15 microg vitamin D(3) significantly increased vitamin D status in these individuals to levels of sufficiency. Achievement of an optimum vitamin D status among young adults may have future positive health implications.

Copper supplementation has no effect on markers of DNA damage and liver function in healthy adults (FOODCUE project).

BACKGROUND/AIMS: Copper is routinely used in the laboratory to promote oxidation in vitro. However, copper concentrations are million-fold higher than physiological concentrations and, in contrast, accumulating evidence suggests that copper may have an antioxidant role in vivo. The aim of this study was to provide data on how increased intake of copper affected mononuclear leukocyte DNA damage and liver function in healthy young free-living men and women. METHODS: The study design was a double-blind repeated crossover trial with treatment and intervening placebo periods, each of 6 weeks' duration. The following supplementations were given orally in sequence: CuSO(4) at a dose of 3 mg copper/day and copper amino acid chelates at doses of 3 and 6 mg copper/day. Oxidative DNA damage was assessed using a modification of the alkaline Comet assay incorporating an endonuclease III digestion step. The assessment of liver function was by measurement of the liver enzymes, alanine aminotransferase and L-gamma-glutamyltransferase. RESULTS: There was no significant alteration in mononuclear leukocyte DNA damage or on liver function after 6 weeks of copper supplementation at two doses (3 and 6 mg/day). CONCLUSIONS: Copper supplementation (giving total copper intake at the highest level of 7 mg/day) did not induce DNA damage or adversely affect liver function in healthy adults.

No effect of copper supplementation on biochemical markers of bone metabolism in healthy young adult females despite apparently improved copper status.

OBJECTIVE: To investigate the effects of increasing Cu intakes, above the usual dietary intake, on biomarkers of bone metabolism in healthy young adult females (aged 21-28 y) over a 4 week period. DESIGN: A double-blind, placebo-controlled randomised repeat crossover Cu supplementation trial. SETTING: The study was conducted at the Royal Veterinary and Agricultural University (RVAU), Copenhagen, Denmark. SUBJECTS: Sixteen healthy young adult females aged 20-28 y were recruited from among students at the RVAU. INTERVENTION: During the 4 week intervention periods in this randomised, crossover trial (3x4 weeks with a minimum 3 week wash-out period), each subject received, in addition to their usual diet, either 3 or 6 mg elemental Cu/day as CuSO4 or a matching placebo. On the last 3 days of each dietary period 24 h urines were collected. In addition, blood was collected on the last day of each dietary period. RESULTS: Serum Cu and erythrocyte superoxide dismutase (but not caeruloplasmin protein concentration or activity (putative indices of Cu status)) were significantly increased (P<0.05) after daily Cu supplementation with 3 and 6 mg/day for 4 weeks. Serum osteocalcin (biomarker of bone formation), urinary creatinine (Cr) concentration, urinary pyridinoline (Pyr)/Cr or deoxypyridinoline (Dpyr)/Cr excretion, or daily urinary Pyr or Dpyr excretion (biomarkers of bone resorption) were unaffected by Cu supplementation. CONCLUSION: Copper supplementation of the usual diet in healthy young adult females, while apparently improving Cu status, had no effect on biochemical markers of bone formation or bone resorption over 4 week periods. SPONSORSHIP: Funding from the European Commission.

Copper supplementation in humans does not affect the susceptibility of low density lipoprotein to in vitro induced oxidation (FOODCUE project).

The oxidative modification of low-density lipoprotein cholesterol (LDL) has been implicated in the pathogenesis of atherosclerosis. Copper (Cu) is essential for antioxidant enzymes in vivo and animal studies show that Cu deficiency is accompanied by increased atherogenesis and LDL susceptibility to oxidation. Nevertheless, Cu has been proposed as a pro-oxidant in vivo and is routinely used to induce lipid peroxidation in vitro. Given the dual role of Cu as an in vivo antioxidant and an in vitro pro-oxidant, a multicenter European study (FOODCUE) was instigated to provide data on the biological effects of increased dietary Cu. Four centers, Northern Ireland (coordinator), England, Denmark, and France, using different experimental protocols, examined the effect of Cu supplementation (3 or 6 mg/d) on top of normal Cu dietary intakes or Cu-controlled diets (0.7/1.6/6.0 mg/d), on Cu-mediated and peroxynitrite-initiated LDL oxidation in apparently healthy volunteers. Each center coordinated its own supplementation regimen and all samples were subsequently transported to Northern Ireland where lipid peroxidation analysis was completed. The results from all centers showed that dietary Cu supplementation had no effect on Cu- or peroxynitrite-induced LDL susceptibility to oxidation. These data show that high intakes (up to 6 mg Cu) for extended periods do not promote LDL susceptibility to in vitro-induced oxidation.

Response of putative indices of copper status to copper supplementation in human subjects.

No sensitive functional index is currently available to assess Cu status in healthy human populations. This study evaluated the effect of Cu supplementation on putative indices of Cu status in twelve women and twelve men, aged between 22 and 45 years, who participated in a double-blind placebo controlled crossover study. The study consisted of three 6-week supplementation regimens of 3 mg CuSO4, 3 mg Cu-glycine chelate and 6 mg Cu-glycine chelate, each separated by placebo periods of equal length. Women had significantly higher caeruloplasmin oxidase activity (P < 0.001), caeruloplasmin protein concentration (P < 0.05), and serum diamine oxidase activity (P < 0.01) at baseline than men. Erythrocyte and leucocyte superoxide dismutase activity, leucocyte cytochrome c oxidase activity, and erythrocyte glutathione peroxidase activity did not respond to Cu supplementation. Platelet cytochrome c oxidase activity was significantly higher (P < 0.01), after supplementation with 6 mg Cu-glycine chelate in the total group and in women but did not change in men. Caeruloplasmin oxidase activity was significantly higher (P < 0.05), in men after supplementation with 3 mg Cu-glycine chelate, while caeruloplasmin protein concentration was significantly lower in men after supplementation with 6 mg Cu-glycine chelate (P < 0.05). Serum diamine oxidase activity was significantly higher after all supplementation regimens in the total group and in both men and women (P < 0.01). These results indicate that serum diamine oxidase activity is sensitive to changes in dietary Cu intakes and may also have the potential to evaluate changes in Cu status in healthy adult human subjects.

Severity of acute pancreatitis: a multivariate analysis of oxidative stress markers and modified Glasgow criteria.

BACKGROUND: It is unknown whether measurement of markers of oxidative stress can improve the prediction of severity of acute pancreatitis. METHODS: Consecutive patients admitted with a diagnosis of acute pancreatitis were divided into mild (n = 62) and severe (n = 23) groups based on the Atlanta classification. Plasma oxidative stress markers were measured within 24 h of admission and included ascorbic acid (endogenous antioxidant), protein carbonyl (a marker of protein oxidation), thiobarbituric acid reactive substances (a marker of lipid peroxidation) and myeloperoxidase (a neutrophil enzyme that produces oxidants). Canonical correlation analysis was used to describe the relationship between these markers and the modified Glasgow criteria. Canonical variate analysis was used to define the best variables that could discriminate mild and severe pancreatitis. RESULTS: There was a significant correlation between markers of oxidative stress and the modified Glasgow criteria (first canonical correlation 0.69, P < 0.0001, Wilk's lambda test). Blood urea, serum albumin and white cell count were the best variables that discriminated mild and severe acute pancreatitis, and all were better than the oxidative stress markers. CONCLUSION: The markers of oxidative stress were highly correlated with the severity of pancreatitis. They are unlikely to be better than the modified Glasgow criteria in predicting it.

The effect of copper supplementation on red blood cell oxidizability and plasma antioxidants in middle-aged healthy volunteers.

A multicenter European study (FoodCue) was undertaken to provide data on the significance of increased dietary copper as a pro-oxidant or antioxidant in vivo. The present work describes the effect of Cu supplementation on (2,2'-azo-bis(2-amidinopropane) hydrochloride (AAPH)-induced red blood cell oxidation in middle-aged people. Double-blinded copper supplementation was achieved in 26 healthy volunteers (50-70 years) with pills containing 3 mg CuSO(4), 3 mg Cu glycine chelate (CuG) and 6 mg CuG. Each 6 week supplementation period was preceded and followed by 6 weeks of washout (WO) on placebo. The results show significant increases in time necessary to achieve 50% hemolysis (LT(50)) after 3CuSO(4) and 6CuG compared with values after WO periods. Cu supplementation did not increase the levels of (Cu,Zn)SOD activity in red blood cells. Resistance to hemolysis was significantly and positively correlated (r =.30, p <.01) with alpha- and beta-carotene content in the plasma. Together, these data suggest that intake of copper as high as 7 mg/d has no pro-oxidant activity and may rather result in protection of red blood cells against oxidation. The decreased oxidizability of red blood cells did not result from increased (Cu,Zn)SOD activity and may occur through other mechanisms such as changes in membrane antioxidant content.

Early ascorbic acid depletion is related to the severity of acute pancreatitis.

BACKGROUND: Ascorbic acid (AA) is an important endogenous antioxidant in plasma and has been shown to be decreased at the time of hospital admission in patients with acute pancreatitis. The aim of this study was to determine whether plasma AA concentration continues to decrease after admission and whether the extent of decrease is related to the severity of pancreatitis. METHODS: Consecutive patients with mild (n = 62) and severe (n = 23) acute pancreatitis had plasma AA concentration measured on the day of recruitment and on days 2 and 5 by high-performance liquid chromatography. RESULTS: The plasma AA concentration in patients with acute pancreatitis was significantly less than that in normal volunteers on days 0, 2 and 5 (P < 0.0001) and this was more marked in those with severe disease. There was a decrease in plasma AA concentration from day 0 to day 2 in patients with mild (P < 0.0001) and severe (P = 0.0005) pancreatitis, and from day 2 to day 5 in patients with severe pancreatitis (P = 0.023). CONCLUSION: Endogenous plasma AA continues to decrease over the first 5 days in hospital and the extent is related to the severity of acute pancreatitis. Presented to a meeting of the Australasian Surgical Research Society, Auckland, New Zealand, August 1995 and published in abstract form as Aust N Z J Surg 1996; 66: 243

Plasma von Willebrand factor and intestinal ischaemia-reperfusion injury in rats.

The purpose of this study was to determine whether plasma von Willebrand factor concentrations are correlated with the degree of intestinal ischaemia-reperfusion injury. Forty-six anaesthetised adult Wistar rats were divided into five groups. The sham-operated group (S, n=10) had laparotomy and isolation of the superior mesenteric artery without clamping. Three ischaemia-reperfusion groups (n=10 in each) had clamping of the superior mesenteric artery for 15, 30, and 45 minutes, respectively, and reperfusion for 15 minutes. A control group (C, n=6) had direct puncture of the heart to sample blood. Mean arterial pressure was measured continuously. Blood was collected at the end of the study to measure von Willebrand factor. The small bowel injury was graded histologically. There was a significant systemic hypotension after declamping in all ischaemia-reperfusion groups, which had a high negative correlation with the histological score (R=-0.46, F=10.1, p<0.003, simple linear regression). Plasma von Willebrand factor was significantly elevated in the three ischaemia-reperfusion groups compared with the control group but not significantly different from the sham-operated group (mean von Willebrand factor concentration (SEM): 156 (29), 283 (29), 295 (25), 381 (44), and 366 (40)% in C, S, ischaemia-reperfusion 15, ischaemia-reperfusion 30, and ischaemia-reperfusion 45 groups, respectively). The concentration of von Willebrand factor was not correlated to the histological score (R=0.22, F=1.83, p<0.2) or the degree of hypotension after the removal of the clamp (R=-0.22, F=1.8, p<0.2, simple linear regression). This study shows that von Willebrand factor concentration does not correlate with the degree of intestinal ischaemia-reperfusion injury. It is unlikely that von Willebrand factor can be used as a predictor of disease severity.

Small bowel ischaemia-reperfusion increases plasma concentrations of oxidised proteins in rats.

OBJECTIVES: To find out whether plasma concentrations of protein carbonyl (a specific marker of oxidative damage of proteins) are increased during intestinal ischaemia-reperfusion and whether they are correlated with von Willebrand's factor (vWF, a marker of endothelial injury) or myeloperoxidase (a marker of neutrophil activation). DESIGN: Randomised experimental study. SETTING: University department of surgery, New Zealand. ANIMALS: Thirty anaesthetised adult Wistar rats. INTERVENTIONS: The sham operated group (n = 10) had laparotomy and isolation of the superior mesenteric artery without clamping. The ischaemia-reperfusion group (IR, n = 10) had the superior mesenteric artery clamped for 1 hour and reperfusion for 15 minutes. The control group (n = 10) had direct puncture of the heart to sample blood. MAIN OUTCOME MEASURES: Plasma concentrations of protein carbonyl, vWF, and myeloperoxidase. RESULTS: Plasma protein carbonyl concentrations were significantly higher in the IR group than in the sham group (p < 0.02, Mann-Whitney test, median (range) 0.187 (0.141-0.242) compared with 0.144 (0.121-0.185) nmol/mg) and in the control group (p < 0.01, Mann-Whitney test, median (range) 0.187 (0.141-0.242) compared with 0.136 (0.108-0.175) nmol/mg). There was a significant correlation between protein carbonyl and vWF concentrations (r = 0.54, F = 10.9, p < 0.003, linear regression) but not with those of myeloperoxidase. CONCLUSION: Intestinal ischaemia-reperfusion caused an increase in the plasma protein carbonyl concentration, which is possibly produced by endothelial cells.