Glucagon-like peptide 2 treatment may improve intestinal adaptation during weaning

Transition from sow's milk to solid feed is associated with intestinal atrophy and diarrhea. We hypothesized that the intestinotrophic hormone glucagon-like peptide 2 (GLP-2) would induce a dose- and health status-dependent effect on gut adaptation. In Exp. 1, weaned pigs (average BW at weaning 4.98 ± 0.18 kg) were kept in a high-sanitary environment and injected with saline or short-acting GLP-2 (80 μg/(kg BW·12 h); n = 8). Under these conditions, there was no diarrhea and GLP-2 did not improve gastrointestinal structure or function. In Exp. 2, weaned pigs (average BW at weaning 6.68 ± 0.27 kg) were kept in a low-sanitary environment, leading to weaning diarrhea, and injected with saline or short-acting GLP-2 (200 µg/(kg BW·12 h); n = 11). Treatment with GLP-2 increased goblet cell density (P < 0.05) and reduced short chain fatty acid concentration in the colon (P < 0.01) but had limited effects on diarrhea. In Exp. 3, weaned pigs (average BW at weaning 6.90 ± 0.32 kg) were kept in a low-sanitary environment and injected with saline or a long-acting acylated GLP-2 analogue (25 µg/(kg BW·12 h); n = 8). In this experiment, GLP-2 increased intestinal weight (+22%; P < 0.01) and activity of brush border enzymes (+50-100%; P < 0.05). Circulating GLP-2 levels were in the pharmacological range in Exp. 3 (constant levels >20,000 pmol/L) and Exp. 2 (increases to 20,000 pmol/L for a few hours each day) while they were in the supraphysiological range in Exp. 1 (50-200 pmol/L). In conclusion, GLP-2 may improve gut structure and function in weanling pigs. However, the effects may be significant only under conditions of diarrhea and if GLP-2 exposure time is extended using long-acting analogues.

Model of influenza A virus infection: dynamics of viral antagonism and innate immune response

Viral antagonism of host responses is an essential component of virus pathogenicity. The study of the interplay between immune response and viral antagonism is challenging due to the involvement of many processes acting at multiple time scales. Here we develop an ordinary differential equation model to investigate the early, experimentally measured, responses of human monocyte-derived dendritic cells to infection by two H1N1 influenza A viruses of different clinical outcomes: pandemic A/California/4/2009 and seasonal A/New Caledonia/20/1999. Our results reveal how the strength of virus antagonism, and the time scale over which it acts to thwart the innate immune response, differs significantly between the two viruses, as is made clear by their impact on the temporal behavior of a number of measured genes. The model thus sheds light on the mechanisms that underlie the variability of innate immune responses to different H1N1 viruses.

The incretin effect does not differ in trained and untrained, young, healthy men

AIM

After both oral and intravenous glucose administration, peripheral insulin concentrations are lower in trained compared with untrained humans. Part of this is explained by an adaptation within the β-cell. The insulin secretion rate is higher after oral compared with intravenous glucose administration due to the release of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) enhancing the glucose-induced insulin secretion (the incretin effect). Our aim was to investigate whether GIP or GLP-1 release or the incretin effect was different in trained compared with untrained humans after oral and intravenous glucose administration.

METHODS

A 3½-h oral glucose tolerance test was performed in eleven trained and ten untrained, young, healthy men. On a separate day, an isoglycaemic intravenous glucose infusion was performed matching the individual glucose concentrations obtained during the oral glucose tolerance test. Blood samples for insulin, C-peptide, GIP and GLP-1 analyses were obtained frequently during both tests, and the insulin secretion rate, incretin effect and insulin clearance were calculated.

RESULTS

Plasma GIP and GLP-1 concentrations, the incretin effect and the insulin clearance did not differ, and plasma glucose, insulin and C-peptide concentrations and the insulin secretion rate were lower in trained compared with untrained subjects during both tests.

CONCLUSION

With no difference in incretin effect and insulin clearance between the two groups, the lower plasma insulin concentrations found in trained compared with untrained, young, healthy men are most likely explained by lower β-cell sensitivity to glucose and enhanced glucose uptake in skeletal muscle in the former group.

Acute effects of continuous infusions of glucagon-like peptide (GLP)-1, GLP-2 and the combination (GLP-1+GLP-2) on intestinal absorption in short bowel syndrome (SBS) patients. A placebo-controlled study

BACKGROUND AND AIMS

The ileocolonic brake is impaired in short bowel syndrome (SBS) patients with distal bowel resections. An attenuated meal-stimulated hormone secretion may cause gastric hypersecretion, rapid gastric and intestinal transit and a poor adaptation. Attempting to restore this ileocolonic brake, this study evaluated the acute effects of continuous intravenous administration of glucagon-like peptide (GLP) 1 and 2, alone or in combination, on gastrointestinal function in SBS patients.

METHODS

SBS patients were admitted 4 times for identical 72-h balance studies, where infusions (1 pmol/kg/min) of GLP-1, placebo (saline), GLP-2 and GLP-1+2 (1 pmol/kg/min of each), were provided. Patients filled out a VAS questionnaire regarding subjective symptoms during treatments. Bone mineral content, body-weight and -composition were measured using DEXA scans. Blood glucose, insulin, pro insulin C-peptide and GLP concentrations were measured in relation to a standardized breakfast.

RESULTS

Nine SBS patients (5 women/4 men, aged 52±11) were enrolled and completed the study; 7 had end-jejunostomies, 2 had 50% of colon-in-continuity. All treatments significantly reduced the fecal wet weight, energy, nitrogen, sodium and potassium losses compared to placebo. However, only GLP-2 containing treatments increased absolute absorption of wet weight and sodium. Only GLP-1+2 improved the hydrational status evaluated by DEXA increases in the fat mass and calculated total body weight. GLP-1 and GLP-1+2 reduced the post-prandial blood glucose levels. A tendency of nausea and reduced appetite was seen in relation to GLP-1 treatment, but this was ameliorated by the co-administration of GLP-2.

CONCLUSION

GLP-1 decreased diarrhea and fecal excretions in SBS patients, but it seems less potent than GLP-2. The combination of GLP-1+2 numerically provided additive effects on intestinal absorption compared to either peptide given alone. Larger, long-term studies should further assess the potential of the glucagon-like peptides or analogs, alone or in combination, in the treatment of SBS patients.

[Metaanalysis for the evaluation of risk factors for carpal tunnel syndrome (CTS) Part I. General factors]

AIM

The expert committee of the German Ministry for Labour and Social Affairs suggested carpal tunnel syndrome (CTS) as an "occupational disease". This systematic literature review and metaanalysis was aimed at identifying associated and risk factors for CTS. Part I addresses the general factors and possible concurrent factors of CTS. These results may be helpful in later experts' reviews of the "occupational disease CTS".

METHODS

A systematic literature review was performed by examining papers in PubMed, Cochrane, EMBASE and Web of Science databases that were published on or before February 15th, 2011. A total of 87 studies (27 longitudinal and 60 cross-sectional) were included in this metaanalysis. The PRISMA (preferred reporting items for systematic reviews and metaanalyses) guidelines for performing a metaanalysis were strictly followed. All of the effect sizes were calculated using a random effects model.

RESULTS

The CTS prevalence in all studies independent of study type was 10.6 % (95 % CI 7.8-14.2). The crude incidence calculated from the longitudinal studies was 10.4 (95 % CI 8.9-11.9)/1000 person years. Female patients more frequently suffered from CTS [OR = 1.9 (95 % CI 1.6-2.2), p < 0.001]. The prevalence of CTS was correlated with an increase in age. The highest prevalence was observed in middle-aged patients (40 to 60 years old). Other significant CTS-associated factors were overweight or obesity [OR = 1.4 (95 % CI 1.3-1.6), p < 0.001]. CTS more frequently occurred in the dominant hand [OR = 1.8 (95 % CI 1.4-2.3), p < 0.001] and in persons of "non-white race" [OR = 1.6 (95 % CI 1.2-1.9), p < 0.001]. Furthermore, CTS was often associated with numerous other general diseases. Real risk factors (results from longitudinal studies) were the following: female gender [OR = 3.7 (95 % CI 2.6-5.2), p < 0.001], middle age [OR = 2.2 (95 % CI 0.9-4.9), p < 0.001], overweight or obesity [OR = 1.5 (95 % CI 1.1-1.9), p < 0.001], diabetes mellitus [OR = 5.3 (95 % CI 1.6-16.8), p < 0.001], and excessive alcohol abuse [OR = 2.3 (95 % CI 0.7-2.3), p < 0.001].

CONCLUSION

CTS is an extremely frequent disease. Independent of occupational burden, many patients are suffering from this frequent peripheral nervous compressive syndrome. These data will be essential in later experts' reviews of the "occupational disease CTS".

[Metaanalysis for the evaluation of risk factors for carpal tunnel syndrome (CTS) Part II. Occupational risk factors]

AIM

The expert committee of the German Ministry for Labour and Social Affairs suggested carpal tunnel syndrome (CTS) as an "occupational disease". This systematic literature review and metaanalysis was aimed at identifying associated and risk factors for CTS. Part II addresses the occupational factors of CTS.

MATERIAL AND METHOD

A systematic literature review was performed by examining papers in PubMed, Cochrane, EMBASE and Web of Science databases that were published on or before February 15th, 2011. A total of 87 studies (27 longitudinal and 60 cross-sectional) were included in this metaanalysis. The PRISMA (preferred reporting items for systematic reviews and metaanalyses) guidelines for performing a metaanalysis were strictly followed. All of the effect sizes were calculated using a random-effects model.

RESULTS

The prevalence of CTS in working populations [10.9 % (95 % CI 7.9-14 : 9)] was significantly higher than in the general population [8.2 % (95 % CI 2.3-25.1), p < 0.001]. Working people had a CTS incidence of 17.3 (95 % CI 14.5-20.1)/1,000 person years. In contrast, the crude incidence in the general population was 1.8 (95 % CI 1.4-2.2)/1.000 person years (p < 0.001). The heterogeneity of the different study designs made it impossible to detect concrete prevalence or incidence rates for specific job groups. However, "blue-collar work" was a significant risk factor for CTS [OR = 3.1 (95 % CI 1.9-5.3), p < 0.001]. Thus, it makes sense to evaluate concrete hand burdens. In numerous studies, some factors were associated with CTS: repetition [OR = 2.7 (95 % CI 1.8-39), p < 0.001), chronic wrist flexion [OR = 1.7 (95 % CI 1.0-2.6), p = 0.033], powerful grip [OR = 4.4 (95 % CI 1.4-13.6), p = 0.009], and chronic vibration load [OR = 2.6 (95 % CI 1.7-4.0)]. Primarily, combined hand loadings were estimated. For this evaluation, the hand activity level threshold limit values (HAL TLVs®) of the ACGIH (American Conference of Governmental Hygienists) were useful. Manual work in the 4th quartile of this score was significantly associated with the prevalence of CTS [OR = 2.9 (95 % CI 1.5-5.7), p = 0.001]. These score values were identified as a significant risk factor for occupational CTS.

CONCLUSION

It was impossible to define exact prevalences or incidences of CTS for specific job titles. However, it was possible to identify manual loadings with a significantly higher risk or association with CTS, including repetition, wrist flexion, powerful grip, and vibration. These loadings are usually combined during occupational work. Subsequent experts' reviews have to respect these complex hand loadings. It may be useful to use instruments, such as HAL TLVs®.

Randomised controlled trial of colostrum to improve intestinal function in patients with short bowel syndrome

BACKGROUND/OBJECTIVES

Colostrum is rich in immunoregulatory, antimicrobial and trophic components supporting intestinal development and function in newborns. We assessed whether bovine colostrum could enhance intestinal adaptation and function in adult short bowel syndrome (SBS) patients.

SUBJECTS/METHODS

Twelve SBS patients in this randomised cross-over study received 4 weeks oral supplement of bovine colostrum or an iso-energetic and iso-proteinaceous control (2.4 MJ/d, 500 ml/day) separated by a 4-week washout period. Patients were admitted four times for 72-h periods of fluid, electrolyte and nutrient balance studies. Meals, faeces and urine were weighed, and energy, macronutrient and electrolyte contents were analysed to calculate net nutrient uptake. Body composition was measured by dual-energy X-ray absorptiometry scans, and functional tests of handgrip strength and lung functions were performed. Eight patients completed the study and were included in the analysis.

RESULTS

Both supplements (colostrum and control) not only increased protein (0.96 ± 0.42 MJ/d, P=0.004 1.03 ± 0.44 MJ/d, P=0.003) and energy (1.46 ± 1.02 MJ/d, P=0.005, 1.76 ± 1.46 MJ/d, P=0.01) absorption but also absolute faecal wet weight excretions (231 ± 248 g/d, P=0.002, 319 ± 299 g/d, P=0.03), compared with baseline measurements. Both supplements improved handgrip strength (P=0.03) while only the control supplement increased lean body mass (1.12 ± 1.33 kg, P<0.049). Colostrum was not found to be superior to the control.

CONCLUSION

Intake of high-protein milk supplements increased net nutrient absorption for adult SBS patients, but at the expense of increased diarrhoea. Despite high contents of bioactive factors, colostrum did not significantly improve intestinal absorption, body composition or functional tests compared with the control.