Energy expenditure of rugby players during a 14-day in-season period, measured using doubly labelled water.

Criterion data for total energy expenditure (TEE) in elite rugby are lacking, which prediction equations may not reflect accurately. This study quantified TEE of 27 elite male rugby league (RL) and rugby union (RU) players (U16, U20, U24 age groups) during a 14-day in-season period using doubly labelled water (DLW). Measured TEE was also compared to estimated, using prediction equations. Resting metabolic rate (RMR) was measured using indirect calorimetry, and physical activity level (PAL) estimated (TEE:RMR). Differences in measured TEE were unclear by code and age (RL 4369 ± 979; RU 4365 ± 1122; U16, 4010 ± 744; U20, 4414 ± 688; U24, 4761 ± 1523 Kcal day- 1). Differences in PAL (overall mean 2.0 ± 0.4) were unclear. Very likely differences were observed in RMR by code (RL 2366 ± 296; RU 2123 ± 269 Kcal day- 1). Differences in relative RMR between U20 and U24 were very likely (U16, 27 ± 4; U20, 23 ± 3; U24, 26 ± 5 Kcal kg- 1 day- 1). Differences were observed between measured and estimated TEE, using Schofield, Cunningham and Harris-Benedict equations for U16 (187 ± 614, unclear; - 489 ± 564, likely and - 90 ± 579, unclear Kcal day- 1), U20 (- 449 ± 698, likely; - 785 ± 650, very likely and - 452 ± 684, likely Kcal day- 1) and U24 players (- 428 ± 1292; - 605 ± 1493 and - 461 ± 1314 Kcal day- 1, all unclear). Rugby players have high TEE, which should be acknowledged. Large inter-player variability in TEE was observed demonstrating heterogeneity within groups, thus published equations may not appropriately estimate TEE.

The metabolic inter-relationships between changes in waist circumference, triglycerides, insulin sensitivity and small, dense low-density lipoprotein particles with acute weight loss in clinically obese children and adolescents.

OBJECTIVE: Small, dense low-density lipoprotein (LDL) particles are highly atherogenic and strongly associated with obesity-related dyslipidemia. The metabolic inter-relationships between weight loss induced changes in waist circumference, triglycerides, insulin sensitivity and small-dense LDL particles in clinically obese children and adolescents have not been studied. METHODS: Seventy-five clinically obese boys and girls (standardized body mass index 3.07 ± 0.59, aged 8-18 years) were recruited. Anthropometric, body composition and cardiometabolic risk factors were measured pre- and post-weight loss. RESULTS: There were highly significant reductions in anthropometric, body composition and cardiometabolic risk factors. Triglyceride change was positively correlated with LDL peak particle density and percentage LDL pattern B changes (relative abundance of small, dense LDL particles). Multiple regression analyses showed that changes in triglyceride concentration accounted for between 24 and 18% of the variance in LDL peak particle density and percentage LDL pattern B change, respectively. Changes in waist circumference and insulin sensitivity did not predict these changes in LDL characteristics. CONCLUSION: Acute and highly significant weight loss significantly decreased LDL peak particle density and percentage LDL pattern B. The change in triglycerides was a strong predictor of LDL peak particle density and percentage LDL pattern B change.

Reliability of a high-intensity endurance cycling test.

This study assessed the reproducibility of performance and selected metabolic variables during a variable high-intensity endurance cycling test. 8 trained male cyclists (age: 35.9 ± 7.7 years, maximal oxygen uptake: 54.3 ± 3.9 mL·kg - 1·min - 1) completed 4 high-intensity cycling tests, performed in consecutive weeks. The protocol comprised: 20 min of progressive incremental exercise, where the power output was increased by 5% maximal workload (Wmax) every 5 min from 70% Wmax to 85% Wmax; ten 90 s bouts at 90% Wmax, separated by 180 s at 55% Wmax; 90% Wmax until volitional exhaustion. Blood samples were drawn and heart rate was monitored throughout the protocol. There was no significant order effect between trials for time to exhaustion (mean: 4 113.0 ± 60.8 s) or total distance covered (mean: 4 6126.2 ± 1 968.7 m). Total time to exhaustion and total distance covered showed very high reliability with a mean coefficient of variation (CV) of 1.6% (95% Confidence Intervals (CI) 0.0 ± 124.3 s) and CV of 2.2% (95% CI 0.0 ± 1904.9 m), respectively. Variability in plasma glucose concentrations across the time points was very small (CV 0.46-4.3%, mean 95% CI 0.0 ± 0.33 to 0.0 ± 0.94 mmol·L - 1). Plasma lactate concentrations showed no test order effect. The reliability of performance and metabolic variables makes this protocol a valid test to evaluate nutritional interventions in endurance cycling.

Effects of the Magenstrasse and Mill operation for obesity on plasma plasminogen activator inhibitor type 1, tissue plasminogen activator, fibrinogen and insulin.

Plasminogen activator inhibitor 1 (PAI-1), tissue plasminogen activator (t-PA), fibrinogen and insulin were measured in 43 patients 3 years after they had undergone the Magenstrasse and Mill (MM) procedure and in 43 morbidly obese (MO) patients. Mean plasma PAI-1 was 61 ng/ml in the MO group compared to 30 ng/ml in the MM group (p < 0.0001); mean plasma t-PA was 10 ng/ml in the MO group compared to 7 ng/ml in the MM group (p < 0.001). Mean fibrinogen was 3.6 g/l in the MO group compared to 3.2 g/l in the MM group (p < 0.05). Mean plasma insulin levels were 32 U/ml in the MO group compared to 15 U/ml in the MM group. These changes suggest that use of the MM procedure may reduce mortality and morbidity from coronary heart disease in these high-risk obese patients.

Effects of the Magenstrasse and Mill operation for obesity on plasma leptin and insulin resistance.

BACKGROUND: We evaluated the effect of the Magenstrasse and Mill (M & M) operation--a new form of non-banded vertical gastroplasty-on weight loss, plasma leptin levels and insulin resistance. METHODS: Fasting plasma glucose, leptin and insulin levels were measured in 12 normal controls, 39 morbidly obese patients and 39 patients a median 3 years after the M & M procedure. Insulin resistance was calculated by the homeostasis model insulin resistance index. RESULTS: Body mass index mean (s.d.) decreased significantly (p < 0.0001), from 48(7) to 33(5) kg/m2, after the M & M procedure. Fasting plasma leptin concentration in the morbidly obese group was 37.9(15.4) ng/ml, significantly (p < 0.0001) higher than the control group (12.2(8.4)) and the M & M group (19.1(12.7)) ng/ml. Fasting plasma insulin concentrations were also significantly (p < 0.0001) higher in the morbidly obese group compared with than in the M & M group or in the control group: 35.5(22.3) mU/l, 15.5(7.1) mU/l and 13.6(3.4) mU/l, respectively. Insulin resistance was 9.6(7.2) in the morbidly obese group and 3.5(1.9) in the M & M group (p < 0.0001). CONCLUSION: This is one of the first studies to show that the decrease in insulin resistance after weight loss achieved by anti-obesity surgery is associated with significantly lower levels of plasma leptin.

The effect of hOGG1 and glutathione peroxidase I genotypes and 3p chromosomal loss on 8-hydroxydeoxyguanosine levels in lung cancer.

Polymorphic genes for the peroxide scavenger glutathione peroxidase I (GPX1) and 8-hydroxydeoxyguanosine (8-OHdG) DNA glycosylase/apurinic (AP) lyase (hOGG1) map to loci on chromosome 3p which are subject to frequent loss of heterozygosity (LOH) in lung tumours. Levels of the pro-mutagenic, oxidative DNA lesion 8-OHdG, were measured in 37 paired normal and tumorous lung specimens using HPLC with electrochemical detection. Lung tumours were also analysed for 3p LOH by fluorescent PCR with Genescan analysis. No significant difference was observed between 8-OHdG levels in tumour [7.7 +/- 6.7 (mean +/- SE) 8-OHdG/10(6) 2'-deoxyguanosine (dG)] and normal (8.1 +/- 8.8 8-OHdG/10(6) dG) lung tissue. Adduct levels in normal lung tissue DNA were not associated with constitutive hOGG1 genotype although there was a trend towards lower 8-OHdG levels in individuals possessing the ALA6 GPX1 polymorphism. Lung tumours exhibiting 3p LOH (40%) contained higher levels of 8-OHdG adducts (10.9 +/- 2.6 8-OHdG/10(6) dG) (P = 0.05) and lower GPX1 enzyme activity [45.5 nmol glutathione (GSH)/min/mg] (P = 0.09) when compared with tumours without LOH at these sites (5.55 +/- 0.87 8-OHdG/10(6) dG and 63.6 nmol GSH/min/mg, respectively). In conclusion, tumours with 3p LOH at loci associated with hOGG1 and GPX1 appear to have compromised oxidative defence mechanisms as measured by reduced GPX1 enzyme activity and elevated 8-OHdG levels and this may affect the prognosis of lung cancer patients.

The effect of longer-term creatine supplementation on elite swimming performance after an acute creatine loading.

We investigated the effect of an acute creatine loading (25 g per day for 4 days) and longer-term creatine supplementation (5 g of creatine or 5 g of placebo per day for 2 months) on the performance of 22 elite swimmers during maximal interval sessions. After the acute creatine loading, the mean of the average interval swim times for all swimmers (n = 22) improved (44.3+/-16.5 s before vs. 43.7+/-16.3 s after supplementation; P<0.01). Three of the 22 swimmers did not respond positively to supplementation. After 2 months of longer-term creatine supplementation or placebo, neither group showed a significant change in swimming performance (38.7+/-13.5 s before vs. 38.7+/-14.1 s after for the creatine group; 48.7+/-18.0 s before vs. 48.7+/-18.1 s after for the placebo group). We conclude that, in elite swimmers, 4 days of acute creatine loading improves swimming performance significantly when assessed by maximal interval sessions. However, longer-term supplementation for 2 months (5 g of creatine per day) did not benefit significantly the creatine group compared with the placebo group.

Early increase in intestinal permeability in patients with severe acute pancreatitis: correlation with endotoxemia, organ failure, and mortality.

Sepsis accounts for 80% of deaths from acute pancreatitis. This study aimed to investigate early changes in intestinal permeability in patients with acute pancreatitis, and to correlate these changes with subsequent disease severity and endotoxemia. The renal excretion of enterally administered polyethylene glycol (PEG) 3350 and PEG 400 was measured within 72 hours of onset of acute pancreatitis to determine intestinal permeability. Severity was assessed on the basis of APACHE II scores and C-reactive protein measurements. Serum endotoxin and antiendotoxin antibodies were measured on admission. Eight-five patients with acute pancreatitis (mild in 56, severe in 29) and 25 healthy control subjects were studied. Urinary excretion of PEG 3350 (median) was significantly greater in patients who had severe attacks (0.61%) compared to those with mild disease (0.09%) and health control subjects (0.12%) (P <0. 0001), as was the permeability index (PEG 3350/400 excretion) (P <0. 00001). The permeability index was significantly greater in patients who subsequently developed multiple organ system failure and/or died compared with other severe cases (0.16 vs. 0.04) (P = 0.0005). The excretion of PEG 3350 correlated strongly with endotoxemia (r = 0.8; P = 0.002). Early increased intestinal permeability may play an important role in the pathophysiology of severe acute pancreatitis. Therapies that aim to restore intestinal barrier function may improve outcome.

Bile reflux and intestinal metaplasia in gastric mucosa.

AIM: To determine associations between enterogastric bile reflux and gastric mucosal pathology. METHOD: A retrospective study using fasting gastric juice bile acid measurements and antral or prestomal biopsy specimens from 350 patients, 66 of whom had previously undergone surgery that either bypassed or disrupted the pyloric sphincter. RESULTS: Bile reflux was positively associated with reactive gastritis and negatively with Helicobacter pylori density. After stratification for previous surgery, age, and H pylori status, the histological feature most strongly associated with bile reflux was intestinal metaplasia, including all its subtypes. The prevalence of intestinal metaplasia was greatest in patients with both H pylori infection and high bile acid concentrations. Bile reflux was also positively associated with the severity of glandular atrophy, chronic inflammation, lamina propria oedema and foveolar hyperplasia. CONCLUSIONS: Bile reflux is a cause of reactive gastritis. It modifies the features of H pylori associated chronic gastritis. The changes are not confined to patients who have had surgery to their stomachs. The positive associations with atrophy and intestinal metaplasia have implications for models of gastric carcinogenesis.

The effect of treatment with recombinant human erythropoietin on the histological appearance and glycogen content of skeletal muscle in patients with chronic renal failure treated by regular hospital haemodialysis.

The effect of treatment with recombinant human erythropoietin on the histological appearance and glycogen content of the anterior tibialis muscle was studied in 10 patients with chronic renal failure treated by regular haemodialysis. Repeat muscle biopsies taken when the target haemoglobin concentration of 11 g/dl was achieved showed an increase in median glycogen content from 35 mg/g fat-free dry muscle to 51 mg/g (p < 0.05). The histological appearance showed a marked improvement in muscle fibre diameters, in particular for the type I fibres and a reduction in cytoarchitectural abnormalities. These changes would be expected to produce an increase in both muscle strength and performance and are most probably a consequence of an increase in muscle oxygen delivery.

Evidence for the indirect utilization of glucose for the synthesis of hepatic glycogen in man.

1. This study was designed to test the hypothesis that three-carbon intermediates can be used in the 'indirect' pathway of glycogen synthesis in human liver (i.e. a route additional to the use of glucose by the 'direct' pathway). 2. After an overnight fast, 13 patients were given an infusion of 20% (w/v) glucose before elective abdominal operation. All received a 2.5 g bolus of 2220 kBq of selectively 3H- and 14C-labelled glucose before removal of a 1 g biopsy of liver. 3H and 14C were determined in purified glycogen as well as in glucose and lactate from samples of peripheral blood. 3. The ratio and specific activities of 3H and 14C in glycogen were found to be significantly lower than those in administered glucose. By calculation, 7-74% of glycogen repletion occurred by indirect pathways and not all of this was from the glucose supplied. 4. This study suggests that the operation of a direct pathway in man is not exclusive and that significant repletion of hepatic glycogen occurs by an indirect route.

24-hour intragastric pH measurement in the assessment of duodenogastric reflux.

In this study we compared the results of measurement of duodenogastric reflux using 24-hour intragastric pH monitoring and nasogastric aspiration with analysis of bile acid and alpha amylase concentrations. Eight patients were studied at least 5 months after biliary and/or gastric surgery. The correlation coefficient of pH and bile acid concentration was 0.36 (p less than 0.001) and of pH and amylase concentration was 0.48 (p less than 0.001). If a pH greater than 4.0 was taken to indicate duodenogastric reflux this had a sensitivity of 84% compared with either high bile acid or amylase concentration. Bile acid concentration has been the "standard" method of measuring duodenogastric reflux. pH monitoring is relatively simple to perform, causes little patient distress, and can measure episodes of duodenogastric reflux over a continuous 24-hour period.

Myectomy reduces ileal motility after ileoanal anastomosis.

The hypothesis tested was that myectomy of the distal ileum would produce a long-lasting decrease in ileal motility, and so render single-lumen ileum more suitable for use as a rectal substitute in the course of restorative proctocolectomy, without the need for a pelvic ileal reservoir. Ileal motility, both spontaneous and in response to intraluminal volatile fatty acids (VFA), was studied after proctocolectomy in 25 female adult beagles, at least 6 months after ileoanal anastomosis alone (IAA, n = 6), IAA with myectomy (n = 8), IAA with myectomy and an ileal valve (n = 5) or IAA with a duplicated (J) ileal reservoir (n = 6). VFA were found to stimulate ileal motility significantly in each group. Myectomy significantly reduced the number of ileal contractions (P less than 0.01), the mean amplitude of contractions (P less than 0.05) and the motility index (P less than 0.01). The addition of the valve to myectomy made no significant difference.

Levels of nitrite, nitrate, N-nitroso compounds, ascorbic acid and total bile acids in gastric juice of patients with and without precancerous conditions of the stomach.

To determine the relevance of gastric juice factors to gastric carcinogenesis, 56 patients with unoperated stomachs undergoing endoscopy for dyspepsia had gastric juice aspirated and analysed for pH, ascorbic acid, total bile acids, nitrite, nitrate and total nitroso compounds (NOCs). Plasma was obtained for vitamin C estimation. Antral and body biopsies were assessed for gastritis, Helicobacter pylori, atrophy and intestinal metaplasia (IM). Patients with chronic atrophic gastritis (n = 17) had lower gastric juice ascorbic acid concentrations (P less than 0.001), higher pH (P less than 0.05) and higher incidence of H. pylori infection (P less than 0.001) than normal subjects (n = 12). Patients with reflux gastritis (n = 9) had higher total bile acids (P less than 0.01). Patients with chronic gastritis and IM (n = 11) had higher gastric juice pH (P less than 0.01) and total bile acid concentrations (P less than 0.05), and lower gastric ascorbic acid concentrations (P less than 0.01) than those with chronic gastritis and no IM (n = 24). In chronic gastritis, high nitrite concentrations were associated with high pH (P less than 0.01). However, there were no significant differences in plasma vitamin C or gastric nitrite, nitrate or total NOC concentrations in relation to gastric histology. We conclude that the premalignant condition IM is associated with H. pylori infection, low gastric ascorbic acid levels and elevated total bile acids, but not to elevation in nitrite or total NOCs in fasting gastric juice.

Single lumen ileum with myectomy: a possible alternative to the pelvic reservoir in restorative proctocolectomy.

An alternative procedure to construction of a pelvic ileal reservoir was assessed which avoids the need for a pouch, while providing an adequate rectal substitute and good continence. Thirty-six female adult beagles were allotted randomly to undergo total colectomy with (a) ileo-anal anastomosis alone, (b) ileo-anal anastomosis with two 15 cm myectomies, (c) ileo-anal anastomosis and myectomy with an ileo-ileal valve, or (d) ileo-anal anastomosis with a duplicated J pouch. The animals were studied before operation and at 4-weekly intervals for 20 weeks after operation. Mortality rates were similar. Ileal compliance was increased significantly by myectomy from 0.64 ml/mmHg (median, interquartile range 0.49-0.78) after ileo-anal anastomosis alone to 1.65 mmHg (1.16-1.93), P less than 0.01, an increase which was maintained. Ileal capacity was also increased both by myectomy and by the J pouch: ileo-anal anastomosis = 85 ml (75-100 ml), ileo-anal anastomosis and myectomy = 139 ml (116-156 ml), ileo-anal anastomosis and myectomy and ileo-ileal valve = 125 ml (range 85-145 ml), ileo-anal anastomosis and J pouch = 130 ml (range 75-165 ml) (P less than 0.01). Bowel function in the other three groups was markedly superior to ileo-anal anastomosis alone. Mean transit time was significantly less after ileo-anal anastomosis, 5.2 h (2.6-8.2 h) than after both ileo-anal anastomosis and myectomy, 10.5 h (9.6-13.9 h), P less than 0.05 and ileo-anal anastomosis and J pouch, 11.0 h (8.4-13.0 h), P less than 0.05, but addition of an ileo-ileal valve did not produce a further increase in transit time, 12.9 h (range 10.5-14.5 h), P = n.s.. Myectomy of single lumen ileum may be a useful alternative to a pelvic ileal reservoir in restorative proctocolectomy.

Is antral gastrin important in the resistance of duodenal ulcers to H2 receptor antagonists or in recurrent ulceration after highly selective vagotomy?

Basal serum gastrin, integrated gastrin response to a meal, and integrated gastrin response to insulin induced hypoglycaemia were measured in 60 patients with duodenal ulcer before and after elective highly selective vagotomy to determine whether antral gastrin has a role in resistance to H2 receptor antagonist treatment which the patients had received before surgery or in the development of recurrent ulceration after vagotomy. The basal gastrin, integrated gastrin response to a meal, and the integrated gastrin response to insulin were similar in patients whose ulcers healed after H2 receptor agonist treatment or were refractory to at least three months of this treatment. The same parameters measured before or after highly selective vagotomy were similar in patients who eventually developed recurrent ulceration compared with those who did not. As expected the basal and meal stimulated (but not insulin stimulated) serum gastrin values increased after highly selective vagotomy. Ulcer patients with particularly high gastrin values (whether basal or stimulated) were not more resistant to H2 receptor antagonist treatment or prone to develop ulcer recurrence after highly selective vagotomy. This study suggests that antral gastrin is not important in 'resistance' of duodenal ulceration either to H2 receptor antagonist treatment or to highly selective vagotomy.

Reflux gastritis in the intact stomach.

Gastric biopsy specimens from patients who have undergone gastric surgery frequently exhibit foveolar hyperplasia, oedema, vasodilatation and congestion, and a paucity of inflammatory cells as consequences of entero-gastric reflux. Similar, albeit generally milder, changes were found in 47 of 316 (15%) non-surgical patients undergoing endoscopy for dyspeptic symptoms. To relate these changes to bile reflux or other potential gastric irritants the total bile acid concentration was measured in samples of fasting gastric juice, and the use of a symptom questionnaire ascertained the patients' cigarette consumption, use of non-steroidal anti-inflammatory drugs (NSAIDs), and alcohol intake. When patients with reflux gastritis were compared with normal controls (n = 91), significant increases in associated peptic ulceration and NSAID use were found in the group with reflux, but no increases in bile acid concentrations. Indeed, only one patient had evidence of duodenogastric reflux. It is concluded that most cases of "reflux gastritis" in the intact stomach are not due to reflux of bile. Our findings indicate an important pathogenic role for long term NSAID use, in what might be usefully termed type C or "chemical" gastritis.