Adaptation period of laboratory animals after transport: a review

Transporting animals leads to a temporary disturbance of normal physiology (homeostasis). After an adaptation period in the new laboratory, the animals must have returned to their normal physiological state. A literature survey was performedin order to establish the minimum necessary length of the adaptation period of mice, rats and rabbits after transport. The minimum length of the period for adaptation that was considered necessary varied from none to 78 weeks; in most studies an adaptation period of 7 days was considered sufficient. However, in most studies no proper experimental setup had been used: either the controls were housed at a different location, or they were sampled at different time points, as compared to the transported animals. Besides transport per see additional factors like a shift in the light-dark rythm, will also disturb the homeostasis. The separate supply of food and water sources during transport is recommended. More research into the effects of transport stress per se is needed, as well as into the interaction of transport stress with other environmental factors occurring simultaneously

Biometfical genetic analysis of serum Cholesterol response and basal serum HDL cholesterol level in the rabbit

The inheritance of the susceptibility for dietary cholesterol (serum cholesterol response) and of basal serum HDL cholesterol level in the rabbit have been studied by measuring serum total cholesterol levels and HDL cholesterol levels in animalsfrom crosses between hyperresponding and hyporesponding inbred strains. The serum cholesterol response and basal serum HDL cholesterol levels of the resulting six populations (the two parental strains, Fl-hybrid, two baekerosses and F7)were subjected to a biomedical genetic analysis to determine the number of loci involved and the (narrow sense) heritability 0f the two traits. The study revealed that 30% of the individual variation of the serum cholesterol response is under geneticcontrol and that 10 to 16 loci may be involved. The heritability for basal serum HDL cholesterol levels was 50 to 80%, whereas two to five loci may be involved in regulating the basal serum HDL cholesterol level in rabbits

Rabbit serum esterase genotyping and relationship to serum cholesterol response and basal serum HDL cholesterol level

Previous studies have indicated that esterases might be involved in the serum cholesterol response in rabbits. The question addressed in this study is whether in rabbits esterase loci of Linkage Group VI (LG VI) are genetically linked withthe serum cholesterol response to dietary cholesterol or the basal serum HDL cholesterol level. For this purpose the Est-2 and Es-1 genotypes of rabbits in segregating populations derived from a cross between IIIVO/JU (hyporespender andhigh basal serum HDL cholesterol level) and AX/1U (hypettesponder and low basal serum HDL cholesterol level) rabbits were determined. The segregating populations were fed a cholesterol-rich diet for 35 days. Both the Est-2 and Es—1 alleles failed to cosegregate with the serum cholesterol response, whereas a highly significant cosegregation was found with the basal serum HDL cholesterol level. It is concluded that one or more genes of LG VI are regulating the basal serumHDL cholesterol level in rabbits

Evaluating the Validity of a Food Frequency Questionnaire in Comparison with a 7-Day Dietary Record for Measuring Dietary Intake in a Population of Survivors of Colorectal Cancer

Background: Food frequency questionnaires (FFQs) are a commonly used method to assess dietary intake in epidemiological studies. It is important to evaluate the validity of FFQs in the population of interest. Objective: To evaluate the validity of an FFQ for measuring dietary intake in survivors of colorectal cancer (CRC), relative to a 7-day dietary record. Design: Dietary intake was assessed 1 year after the end of CRC treatment. Participants first completed a 7-day dietary record and 2 weeks later a 253-item FFQ that measured intake in the preceding month. Participants/setting: Data were used from a subsample of participants (n=100) enrolled in an ongoing prospective study (EnCoRe study) in the Netherlands, from 2015 to 2018. Main outcome measures: Estimated intakes of total energy, 19 nutrients, and 20 food groups as well as scoring adherence to the dietary recommendations of the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) were compared between both dietary assessment methods. Statistical analyses performed: Means and standard deviations, Spearman rank correlations corrected for within-person variation and total energy, and κ agreement between quintiles were assessed. Results: The median Spearman correlation corrected for within-person variation for nutrients and total energy was 0.60. Correlations >0.50 were found for 15 of 19 nutrients, with highest agreement for vitamin B-12 (0.74), polysaccharides (0.75), and alcohol (0.91). On average, 73% (range=60% to 84%) of participants were classified into the exact same or adjacent nutrient quintile. The median Spearman correlation corrected for within-person variation for food groups was 0.62. Correlations >0.50 were found for 17 of 20 food groups, with highest agreement for cereals and cereal products (0.96), fish (0.96), and potatoes (0.99). The Spearman correlation between total scores of the WCRF/AICR dietary recommendations was 0.53. Conclusions: Relative to a 7-day dietary record, the validity of an FFQ for measuring dietary intake among survivors of CRC appeared moderate to good for most nutrients and food groups.</p

Altered bile acid kinetics contribute to postprandial hypoglycaemia after Roux-en-Y gastric bypass surgery

Background/objectives: Bile acids (BA) act as detergents in intestinal fat absorption and as modulators of metabolic processes via activation of receptors such as FXR and TGR5. Elevated plasma BA as well as increased intestinal BA signalling to promote GLP-1 release have been implicated in beneficial health effects of Roux-en-Y gastric bypass surgery (RYGB). Whether BA also contribute to the postprandial hypoglycaemia that is frequently observed post-RYGB is unknown. Methods: Plasma BA, fibroblast growth factor 19 (FGF19), 7α-hydroxy-4-cholesten-3-one (C4), GLP-1, insulin and glucose levels were determined during 3.5 h mixed-meal tolerance tests (MMTT) in subjects after RYGB, either with (RYGB, n = 11) or without a functioning gallbladder due to cholecystectomy (RYGB-CC, n = 11). Basal values were compared to those of age, BMI and sex-matched obese controls without RYGB (n = 22). Results: Fasting BA as well as FGF19 levels were elevated in RYGB and RYGB-CC subjects compared to non-bariatric controls, without significant differences between RYGB and RYGB-CC. Postprandial hypoglycaemia was observed in 8/11 RYGB-CC and only in 3/11 RYGB. Subjects who developed hypoglycaemia showed higher postprandial BA levels coinciding with augmented GLP-1 and insulin responses during the MMTT. The nadir of plasma glucose concentrations after meals showed a negative relationship with postprandial BA peaks. Plasma C4 was lower during MMTT in subjects experiencing hypoglycaemia, indicating lower hepatic BA synthesis. Computer simulations revealed that altered intestinal transit underlies the occurrence of exaggerated postprandial BA responses in hypoglycaemic subjects. Conclusion: Altered BA kinetics upon ingestion of a meal, as frequently observed in RYGB-CC subjects, appear to contribute to postprandial hypoglycaemia by stimulating intestinal GLP-1 release