Effect of alanyl-glutamine on leucine and protein metabolism in irradiated rats

Summary. The mechanism by which glutamine produces a favorable effect in the treatment of sepsis, injury, burns and abdominal irradiation is not completely understood. The main aim of this study was to evaluate the effect of alanyl-glutamine (AlaGln) administration on the metabolism of proteins in irradiated rats. The rats were exposed to whole-body irradiation (8 Gy) and then fed intragastrically with a mixture of glucose and amino acids either with AlaGln or without AlaGln. At 48 hours after irradiation, parameters of whole-body protein metabolism and DNA synthesis in intestinal mucosa were investigated using a primed, continuous infusion of [1-¹⁴C]leucine and [³H]thymidine. In addition, we evaluated the effect of irradiation and AlaGln on gut morphology, blood count and amino acid concentrations in blood plasma and skeletal muscle. Control rats were not irradiated but were given identical treatment. An increase in whole-body leucine oxidation, and insignificant changes in whole-body proteolysis and in protein synthesis were observed after irradiation. In irradiated rats we observed a decrease in muscle glutamine concentration, a decrease in protein synthesis in jejunum, colon and heart, and an increase in synthesis of proteins of blood plasma and spleen. Morphological examination and measurement of DNA synthesis failed to demonstrate any favorable effect of AlaGln supplementation on irradiated gut. However, administration of AlaGln resulted in a decrease in whole-body proteolysis and leucine oxidation which caused an increase in the fraction of leucine incorporated into the pool of body proteins. We conclude that the data obtained demonstrate that irradiation induces metabolic derangement associated with increased oxidation of essential branched-chain amino acids (valine, leucine and isoleucine) and that these disturbances can be ameliorated by administration of AlaGln. Received February 14, 2000 Accepted July 12, 2000     

Leucine supplementation does not enhance acute strength or running performance but affects serum amino acid concentration

This study described the effect of leucine supplementation on serum amino acid concentration during two different exercise sessions in competitive male power athletes. The subjects performed a strength exercise session (SES; n = 16; 26 +/- 4 years) or a maximal anaerobic running exercise session (MARE; n = 12; 27 +/- 5 years) until exhaustion twice at a 7-day interval. The randomized subjects consumed drinks containing leucine (100 mg x kg/body weight before and during SES or 200 mg x kg/body weight before MARE) or placebo. Blood specimens taken 10 min before (B) and after (A) the sessions were analyzed for serum amino acids. In SES the concentration of leucine was distinctly higher in the leucine supplemented group than in the placebo group in both B (p < 0.001) and A (p < 0.001) samples. The leucine concentration decreased in placebo but not in the leucine supplemented group following the exercise session. Isoleucine (p = 0.017) and valine (p = 0.006) concentration decreased more in the leucine supplemented group than in placebo in A samples. In MARE the concentration of leucine was higher in the leucine supplemented group than in placebo in both B (p < 0.001) and A (p < 0.001) samples and increased (p < 0.001) in the supplemented group following the session. Isoleucine (p = 0.020) and valine (p = 0.006) concentration decreased in the supplemented group in A samples. There were no differences in a counter movement jump after SES or in the running performance in MARE between the leucine supplemented group and placebo. These findings indicate that consuming leucine before or before and during exercise sessions results in changes in blood amino acid concentration. However, the supplementation does not affect an acute physical performance.     

孕妇孕期营养指导及体质量控制对妊娠结局的影响

目的:对孕妇进行孕期营养指导及体质量控制,探究其对妊娠结局的影响。方法:将2011年2月-2014年2月期间我院收治的孕产妇150例纳入本次研究,所有研究对象随机均衡分为研究组和对照组,每组各75例。对照组孕产妇仅行常规妇科检查,研究组孕产妇在医护人员指导下行孕期营养指导和体质量控制,比较两组分娩方式,妊娠过程状况及围产儿情况。结果:研究组剖宫产率为17.33%低于对照组的57.33%,组间差异存在统计学意义(P0.05)。研究组贫血、羊水过少、产后出血率均低于对照组,差异有统计学意义(P0.05)。研究组胎龄及巨大儿及胎儿窘迫率均低于对照组,差异有统计学意义(P0.05)。结论:孕产妇在孕期进行营养膳食指导,控制体质量在合理范围内,可以改善孕妇妊娠结局,降低妊娠过程中并发症发病率,提高围产儿状况,保证孕妇和婴儿健康。     

Emerging roles of PDGF-D signaling pathway in tumor development and progression

Platelet-derived growth factor-D (PDGF-D) can regulate many cellular processes, including cell proliferation, apoptosis, transformation, migration, invasion, angiogenesis and metastasis. Therefore PDGF-D signaling has been considered to be important in human malignancies, and thus PDGF-D signaling may represent a novel therapeutic target, and as such suggests that the development of agents that will target PDGF-D signaling is likely to have a significant therapeutic impact on human cancers. This mini-review describes the mechanisms of signal transduction associated with PDGF-D signaling to support the role of PDGF-D in the carcinogenesis. Moreover, we summarize data on several PDGF-D inhibitors especially naturally occurring “chemopreventive agent” such an indole compound, which we believe could serve as a novel agent for the prevention of tumor progression and/or treatment of human malignancies by targeted inactivation of PDGF-D signaling.     

The foraging behavior of Japanese macaques Macaca fuscata in a forested enclosure:Effects of nutrient composition,energy and its seasonal variation on the consumption of natural plant foods

In the wild, primate foraging behaviors are related to the diversity and nutritional properties of food, which are affected by seasonal variation. The goal of environmental enrichment is to stimulate captive animals to exhibit similar foraging behavior of their wild counterparts, e.g. To extend foraging time. We conducted a 12-month study on the foraging behavior of Japanese macaques in a semi-naturally forested enclosure to understand how they use both provisioned foods and naturally available plant foods and what are the nutritional criteria of their consumption of natural plants. We recorded time spent feeding on provisioned and natural plant foods and collected the plant parts ingested of their major plant food species monthly, when available.We conducted nutritional analysis (crude protein, crude lipid, neutral detergent fiber-'NDF', ash) and calculated total non-slructural carbohydrate - 'TNC' and total energy of those food items. Monkeys spent 47% of their feeding time foraging on natural plant species. The consumption of plant parts varied significantly across seasons. We found that leaf items were consumed in months when crude protein, crude protein-to-NDF ratio, TNC and total energy were significantly higher and NDF was significantly lower, fruit/nut items in months when crude protein and TNC were significantly higher and crude lipid content was significantly lower, and bark items in months when TNC and total energy were higher and crude lipid content was lower. This preliminary investigation showed that the forested enclosure allowed troop members to more fully express their species typical flexible behavior by challenging them to adjust their foraging behavior to seasonal changes of plant item diversity and nutritional content, also providing the possibility for individuals to nutritionally enhance their diet.     

In silico exploration of the effects of host genotype and nutrition on the genetic parameters of lambs challenged with gastrointestinal parasites

An in silico mathematical model was used to explore the effect of, and the interaction between, (i) nutrition, (ii) genotype for growth and (iii) genotype for resistance, on the estimates of genetic parameters for resistance and performance in a population of lambs trickle-challenged daily with 3,000 L3s of Teladorsagia circumcincta. A previously published model for nematode infections in sheep was developed to include heritable variation in sheep growth traits, as well as in immunologically controlled traits such as establishment of incoming larvae, mortality of the adult worms and fecundity of the adult female worms. The simulated population comprised 10,000 lambs, these being the offspring of 250 sires mated to 5,000 dams. The model assumed the lambs to be parasitologically naïve at weaning (2 months of age), at which point the trickle challenge commenced and the model was updated daily until slaughter (at 6 months of age). Dietary treatments included a good and a poor quality feed, offered ad libitum. Two genotypes for growth were assumed: (i) fast and (ii) slow growing. Three genotypes for resistance were used: (i) benchmark, (ii) susceptible and (iii) resistant, differing in their ability to cope with nematode infections. Genetic parameters for output traits, including growth rate, food intake, worm burden and faecal egg count were estimated using a linear mixed model, fitting sire as a random effect to capture genetic effects. Heritabilities and correlations were found to change over time. In general, the heritabilities of immunity traits increased over time, whereas genetic correlations between production and immunity traits became weaker. Diet had a significant effect on the means and the estimated correlations of output traits, while genotypes for growth and resistance had smaller effects. These results suggest that discrepancies between published genetic parameters for nematode resistance may be a function of environmental factors rather than differences in host genotype.     

神农箭竹开花前后植物体内N、P、K元素的动态

对神农箭竹(Fargesia murielae)N、P、K的含量进行分析,结果表明:N、P、K在竹子植物体内呈非均匀分布。N和P在各器官中的分布规律为:叶>鞭、根>竿;K在未开花竹和正开花竹中分布规律为:鞭>根>叶>竿,在已开花竹中分布规律为:叶>鞭>竿>根。随着开花过程的进行,N的含量在叶、竿、鞭和根等器官中逐渐减少;P的含量在竿、鞭和根等器官中逐渐降低,在叶片中先升高后降低;K的含量在鞭和根中呈下降趋势,在竿和叶中先降低后升高。     

Indo-Fijian Children’s BMI

Health research has shown that overweight and obesity in children and adults are becoming significant public health problems in the developing world. Evidence suggests that this phenomenon is more marked in urban than rural areas and may be associated with modernization. However, the underlying reasons for this nutrition transition remain unclear. Dietary shifts, often in conjunction with income and time constraints in urban environments, may entail a greater reliance on more convenient sugar and fat-dense food. Also, the necessity of labor-intensive agricultural work to meet rural subsistence needs is supplanted in urban environments by sedentary work. This paper extends the application of human behavioral ecology theory into the realm of international development and policy by applying Kaplan’s embodied capital theory to explore differences in food habits and nutritional status of Indo-Fijian children within the context of urbanization. Urban high-embodied-capital women demonstrate higher rates of wage-earning employment than urban low-embodied-capital or rural women. Findings indicate that urban high-embodied-capital households spend significantly more on food purchases, purchase a greater proportion of processed foods, and have children with higher body mass indexes (BMI) than do urban low-embodied-capital or rural households. This suggests that urban high-embodied-capital mothers, who tend to be employed, may be making trade-offs between income and food choices.