Glucose absorption and gastric emptying in critical illness

Introduction: Delayed gastric emptying occurs frequently in critically ill patients and has the potential to adversely affect both the rate, and extent, of nutrient absorption. However, there is limited information about nutrient absorption in the critically ill, and the relationship between gastric emptying (GE) and absorption has hitherto not been evaluated. The aim of this study was to quantify glucose absorption and the relationships between GE, glucose absorption and glycaemia in critically ill patients. Methods: Studies were performed in nineteen mechanically ventilated critically ill patients and compared to nineteen healthy subjects. Following 4 hours fasting, 100 ml of Ensure, 2 g 3-Omethyl glucose (3-OMG) and ⁹⁹mTc sulphur colloid were infused into the stomach over 5 minutes. Glucose absorption (plasma 3- OMG), blood glucose levels and GE (scintigraphy) were measured over four hours. Data are mean ± SEM. A P-value 0.51; P < 0.05). Conclusions In critically ill patients; (i) the rate and extent of glucose absorption are markedly reduced; (ii) GE is a major determinant of the rate of absorption, but does not fully account for the extent of impaired absorption; (iii) blood glucose concentration could be one of a number of factors affecting GE.Marianne J Chapman, Robert JL Fraser, Geoffrey Matthews, Antonietta Russo, Max Bellon, Laura K Besanko, Karen L Jones, Ross Butler, Barry Chatterton and Michael Horowit

Association and Haplotype Analyses of Positional Candidate Genes in Five Genomic Regions Linked to Scrotal Hernia in Commercial Pig Lines

Scrotal hernia in pigs is a complex trait likely affected by genetic and environmental factors. A large-scale association analysis of positional and functional candidate genes was conducted in four previously identified genomic regions linked to hernia susceptibility on Sus scrofa chromosomes 2 and 12, as well as the fifth region around 67 cM on chromosome 2, respectively. In total, 151 out of 416 SNPs discovered were genotyped successfully. Using a family-based analysis we found that four regions surrounding ELF5, KIF18A, COL23A1 on chromosome 2, and NPTX1 on chromosome 12, respectively, may contain the genetic variants important for the development of the scrotal hernia in pigs. These findings were replicated in another case-control dataset. The SNPs around the ELF5 region were in high linkage disequilibrium with each other, and a haplotype containing SNPs from ELF5 and CAT was highly significantly associated with hernia development. Extensive re-sequencing work focused on the KIF18A gene did not detect any further SNPs with extensive association signals. These genes may be involved in the estrogen receptor signaling pathway (KIF18A and NPTX1), the epithelial-mesenchymal transition (ELF5) and the collagen metabolism pathway (COL23A1), which are associated with the important molecular characteristics of hernia pathophysiology. Further investigation on the molecular mechanisms of these genes may provide more molecular clues on hernia development in pigs

Use of [14C] - Sodium Bicarbonate Urea to Measure Physical Activity Induced Increases in Total Energy Expenditure in Free-Living Healthy Males

The aim of this study was to evaluate the utility of the [¹⁴C]-sodium bicarbonate/urea technique to detect physical activity-induced increases in total energy expenditure in free-living healthy men. Thirteen healthy males aged 34.1 ± 11.7 yrs with body mass index 24.1 ± 3.1 kg/m2 were studied on three separate occasions, during which [¹⁴C]-bicarbonate was infused over 48-hours and urine was collected during the second 24-hours. On three separate occasions and in random order, subjects either remained sedentary, or performed a bout of physical activity on an electro-magnetically braked cycle ergometer sufficient to increase energy expenditure by 7% or 11% above predicted sedentary total energy expenditure. Urine samples were analyzed to evaluate the amount of [¹⁴C]-bicarbonate incorporated into urinary urea, thereby reflecting the amount of CO₂ produced per day, and upon conversion, the number of kilojoules of energy expended in 24-hours. All 13 subjects successfully completed the two physical activity treatments and there were no adverse events. As measured by the [¹⁴C]-urea assay, mean total energy expenditure values were not significantly different between sedentary activity (17902 ± 905 kJ/day), the physical activity treatment designed to increase TEE by 7% (17701 ± 594 kJ/day) and the physical activity treatment designed to increase TEE by 11% (18538 ± 485 kJ/day) (P=0.668). In conclusion, although the [¹⁴C]-sodium bicarbonate/urea technique was well tolerated and did not interfere with normal daily activities, it was not able to accurately measure physical activity-induced increases in EE in the range of 7-11% above predicted sedentary total energy expenditure.Darren M Roffey, Natalie D Luscombe, Nuala M Byrne, Andrew P Hills, Max Bellon, Chris Tsopelas, Ian D Kirkwood and Gary A Witter