173,349 research outputs found
Sonophoresis efficiency: consequences of methyl donors supplementation at early developmental stage in gilthead seabream (Sparus aurata). Effects on growth, nutrient metabolism, egg and larval quality, and methylation patterns of larvae and juvenile fish
Dissertação de mestrado, Aquacultura e Pescas, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2016It is essential that the vegetable ingredients that will be use in Aquaculture feeds can
maintain the growth parameters in fish when compared with the fish meal diets. Studies
have shown that the replacement may be achieved until a certain level without affecting
the growth parameters. Sometimes the vegetable diets lack essential amino acids that need
to be supplemented in the feeds, one of the amino acids that sometimes is lacking is the
Methionine. In this study the gilthead seabream (Sparus aurata, L. 1758) eggs were
supplemented with Methionine to understand if the supplementation had an effect in the
larvae growth. The supplementation was performing using the innovative technique
Sonophoresis. The amount of Methionine that entered the supplemented eggs was 33.1-
fold higher than in the eggs that were not supplemented. Due to the supplementation the
oil globule area of the larvae of the treatment MET was higher in the 2 and 4 days after
hatching (DAH), also the dry weight was higher in the larvae of treatment MET during
the first week. After the first week the larvae of both treatments presented similar growth
parameters so a later supplementation was planned and performed at 57 DAH. This
second supplementation was done using a Vegetable feed (VEG) supplemented with
methionine. At the end of the experiment the juveniles that were from the eggs
supplemented and were fed with VEG diet (METVEG) presented higher condition factor
(K). In conclusion the Sonophoresis technique was a success, which allowed the alteration
of the composition of the egg with the methionine, the early supplementation was able to
promote growth in gilthead seabream larvae. The VEG diet did not negatively affected
the survival and promoted fish to achieve similar weight to the FM diet
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Medium alkalization due to carbon metabolism is largely responsible for inhibition of bacterial growth by Vibrio cholerae supernatants
Vibrio cholerae is the causative agent of the diarrheal disease cholera. Many Vibrio
species secrete antimicrobial factors, though the identity of such a factor has not been determined
for any V. cholerae strain. Such an antimicrobial factor could be relevant to pathogenesis of
cholera, which disrupts the intestinal microbiome. In this study, we investigated the antimicrobial effects of supernatant from 72 hour old
cultures of V. cholerae C6706 on Shigella flexneri CFS100. Inhibition of S. flexneri growth was
found to be dependent on the alkaline pH of the supernatant. A 1:1 mixture of pH-adjusted
supernatant and LB was found to inhibit S. flexneri growth at alkaline but not neutral pH, as was
pH-adjusted LB alone. In minimal medium, elevation of supernatant pH by V. cholerae was
dependent on nutritional factors, and this elevation of medium pH also correlated with increased
S. flexneri growth inhibition. Though medium alkalization in LB is often attributed to amino acid
catabolism and the consequent production of ammonia, supplementation of V. cholerae cultures
in minimal medium with amino acids had a weaker effect on alkalization and inhibition than did
supplementation with selected carbon sources. This suggests that some feature of carbon
metabolism causes medium alkalization and the resultant antimicrobial activity. Several V.
cholerae mutants in potentially relevant pathways were screened for alkalization and S. flexneri
growth inhibition, but none had any effect.Complicating this picture is the finding that V. cholerae grown under microaerobic
conditions produce a less alkaline supernatant with stronger S. flexneri growth inhibition. The
significance of this is unknown.Molecular Bioscience
Sarcopenia from mechanism to diagnosis and treatment in liver disease
Sarcopenia or loss of skeletal muscle mass is the major component of malnutrition and is a frequent complication in cirrhosis that adversely affects clinical outcomes. These include survival, quality of life, development of other complications and post liver transplantation survival. Radiological image analysis is currently utilized to diagnose sarcopenia in cirrhosis. Nutrient supplementation and physical activity are used to counter sarcopenia but have not been consistently effective because the underlying molecular and metabolic abnormalities persist or are not influenced by these treatments. Even though alterations in food intake, hypermetabolism, alterations in amino acid profiles, endotoxemia, accelerated starvation and decreased mobility may all contribute to sarcopenia in cirrhosis, hyperammonemia has recently gained attention as a possible mediator of the liver-muscle axis. Increased muscle ammonia causes: cataplerosis of α-ketoglutarate, increased transport of leucine in exchange for glutamine, impaired signaling by leucine, increased expression of myostatin (a transforming growth factor beta superfamily member) and an increased phosphorylation of eukaryotic initiation factor 2α. In addition, mitochondrial dysfunction, increased reactive oxygen species that decrease protein synthesis and increased autophagy mediated proteolysis, also play a role. These molecular and metabolic alterations may contribute to the anabolic resistance and inadequate response to nutrient supplementation in cirrhosis. Central and skeletal muscle fatigue contributes to impaired exercise capacity and responses. Use of proteins with low ammoniagenic potential, leucine enriched amino acid supplementation, long-term ammonia lowering strategies and a combination of resistance and endurance exercise to increase muscle mass and function may target the molecular abnormalities in the muscle. Strategies targeting endotoxemia and the gut microbiome need further evaluatio
Leucine supplementation differentially enhances pancreatic cancer growth in lean and overweight mice
Kristyn A Liu1†, Laura M Lashinger1†, Audrey J Rasmussen1† and Stephen D Hursting12*
Author Affiliations
1 Department of Nutritional Sciences, University of Texas at Austin, Austin, TX 78723, USA
2 Department of Molecular Carcinogenesis, University of Texas M.D. Anderson Cancer Center, 1808 Park Road 1c, Smithville, TX 78957, USABackground: The risk of pancreatic cancer, the 4th deadliest cancer for both men and women in the United States, is increased by obesity. Calorie restriction (CR) is a well-known dietary regimen that prevents or reverses obesity and suppresses tumorigenesis in a variety of animal models, at least in part via inhibition of mammalian target of rapamycin (mTOR) signaling. Branched-chain amino acids (BCAA), especially leucine, activate mTOR and enhance growth and proliferation of myocytes and epithelial cells, which is why leucine is a popular supplement among athletes. Leucine is also increasingly being used as a treatment for pancreatic cancer cachexia, but the effects of leucine supplementation on pancreatic tumor growth have not been elucidated. Results: Supplementation with leucine increased pancreatic tumor growth in both lean (104 ± 17 mm3 versus 46 ± 13 mm3; P <0.05) and overweight (367 ± 45 mm3 versus 230 ± 39 mm3; P <0.01) mice, but tumor enhancement was associated with different biological outcomes depending on the diet. In the lean mice, leucine increased phosphorylation of mTOR and downstream effector S6 ribosomal protein, but in the overweight mice, leucine reduced glucose clearance and thus increased the amount of circulating glucose available to the tumor. Conclusion: These findings show that leucine supplementation enhances tumor growth in both lean and overweight mice through diet-dependent effects in a murine model of pancreatic cancer, suggesting caution against the clinical use of leucine supplementation for the purposes of skeletal muscle enhancement in cachectic patients.Nutritional Science
Effects of Selenium Supplementation on Gene Expression Levels of Inflammatory Cytokines and Vascular Endothelial Growth Factor in Patients with Gestational Diabetes
Selenium is known to exert multiple beneficial effects including anti-inflammatory actions. The aim of the study was to evaluate the effects of selenium supplementation on gene expression levels of inflammatory cytokines and vascular endothelial growth factor (VEGF) in women with gestational diabetes (GDM). This randomized double-blind, placebo-controlled trial was carried out among 40 subjects diagnosed with GDM aged 18–40 years old. Subjects were randomly allocated into two groups to receive either 200 μg/day selenium supplements (n = 20) or placebo (n = 20) for 6 weeks. Gene expression of inflammatory cytokines and VEGF were assessed in lymphocytes of GDM women with RT-PCR method. Results of RT-PCR indicated that after the 6-week intervention, compared with the placebo, selenium supplementation downregulated gene expression of tumor necrosis factor alpha (TNF-α) (P = 0.02) and transforming growth factor beta (TGF-β) (P = 0.01), and upregulated gene expression of VEGF (P = 0.03) in lymphocytes of patients with GDM. There was no statistically significant change following supplementation with selenium on gene expression of interleukin (IL)-1β and IL-8 in lymphocytes of subjects with GDM. Selenium supplementation for 6 weeks in women with GDM significantly decreased gene expression of TNF-α and TGF-β, and significantly increased gene expression of VEGF, but did not affect gene expression of IL-1β and IL-8
Hyaluronan and Hyaluronidase, which is better for embryo development?
Our aim was to examine size-specific effects of Hyaluronan (HA) on preimplantation embryo development. We investigated the effects of Hyalovet (HA, 500–750 kDa; the size produced by HA synthase-3, which is abundant in the oviduct), or HA treated with Hyaluronidase-2 (Hyal2; also expressed in the oviduct that breaks down HA into 20 kDa fragments). In experiment 1 (in vivo), oviducts of synchronized and superovulated ewes (n = 20) were surgically exposed on Day 2 post-mating, ligated, and infused with either Hyalovet, Hyalovet + Hyal2, Hyal2, or PBS (control). Ewes were killed 5 days later for recovery of embryos and oviductal epithelial cells (OEC). Blastocyst rates were significantly higher in Hyal2 and Hyalovet + Hyal2 oviducts. Hyaluronidase-2 infusion resulted in higher blastocyst cell numbers and hatching rates. This was associated with increased HSP70 expression in OEC. In contrast, Hyalovet resulted in the lowest development to blastocyst stage and lowest hatching rates, and decreased IGF2 and IGFBP2 expression in OEC. IGF1 and IL1α expression were not affected. In experiment 2, to rule out indirect effects of oviductal factors, ovine embryos were produced and cultured with the same treatments in vitro from Day 2 to 8. Hyaluronidase-2, but not Hyalovet, enhanced blastocyst formation and reduced inner cell mass apoptosis. Hyalovet inhibited hatching. In conclusion, the presence of large-size HA (500–750 kDa) in the vicinity of developing embryos appears to disturb the oviductal environment and embryo development in vivo and in vitro. In contrast, we show evidence that breakdown of HA into smaller fragments is required to maximize embryo development and blastocyst quality
In Vitro Fermentation Characteristics and Rumen Microbial Population of Diet Supplemented with Saccharomyces Cerevisiae and Rumen Microbe Probiotics
The objective of this study was to select three strains of probiotic Saccharomyces cerevisiae and to evaluate the effect of S. cerevisiae and rumen bacteria isolate (MR4) supplementation and their combination on rumen fermentability and rumen microbial population. Experiment 1 was designed in a 4 x 5 factorial randomized block design with 3 replications. The first factor was S. cerevisiae strain consisted of control treatment (without S. cerevisiae supplementation), NBRC 10217, NRRL Y 567 and NRRL 12618, and the second factor was incubation time consisted of 0, 1, 2, 3, and 4 h. Ration was basal ration for feedlot with forage to concentrate ratio (F:C)= 60:40. Dosage of each treatment with S. cerevisiae was 5 x 1010 cfu/kg ration. Experiment 2 was designed in randomized block design with 4 treatments: P0= basal ration of feedlot; P1= P0 + S. cerevisiae; P2= P0 + MR4 isolate (5 x 107 cfu/kg ration); P3= P0 + S. cerevisiae and MR4 isolate. The result of experiment 1 showed that supplementation of S. cerevisiae NRRL 12618 had the highest S. cerevisiae population and increased rumen bacterial population. This strain was selected as probiotic in experiment 2. The result from experiment 2 showed that probiotic supplementation stabilized rumen pH and produced the highest NH3 concentration (P<0.05) and bacterial population (P<0.05). As compared with control, all treatments reduced protozoa population (P<0.05). Combination of S. cerevisiae and MR4 probiotics produced the highest total volatile fatty acids (VFA) and isovalerate (P<0.05). It was concluded that strain S. cerevisiae NRRL 12618 had potential as probiotic yeast. Supplementation with this strain increased fermentability, rumen isoacid and decreased A:P ratio. Those abilities could be improved with MR4 rumen isolate probiotic
The role of zinc in renal pathological changes in diabetic status
Diabetes mellitus (DM) was the 8th leading cause of death in 2011, resulting in 1.4 million deaths worldwide. One of the complications of DM is chronic kidney disease, which accounts for nearly 44% of all new cases of kidney failure in the US in 2011. Zinc (Zn), an essential trace element, plays an important role in regulating carbohydrate metabolism. Several studies have shown the beneficial effects of Zn on renal pathological changes in Type 1 and Type 2 diabetic subjects, by reducing levels of oxidative stress, glomerular damage, and urinary albumin excretion after Zn supplementation. In contrast, other studies have shown little effects of Zn supplementation on renal damage. This paper reviewed recent research developments and found promising results of Zn in reducing, and in some cases, completely preventing renal damage. Nevertheless, the use of Zn as a potential treatment and especially its long-term impact against renal pathological symptoms in DM patients needs to be further studied
Effects of dietary lysine and methionine supplementation on growth, nutrient utilization and carcass compositions in beluga, Huso huso, fed soy protein-based diet
A feeding trial was conducted to examine the effects of dietary supplementation of lysine and methionine on growth, nutrient utilization and carcass compositions in beluga, Huso huso. Four experimental soy protein based diets D0 (without lysine or methionine supplementation), D1 (lysine supplementation alone), D2 (methionine supplementation alone) and D3 (both lysine and methionine supplementation) were fed to triplicate groups. 240 fish with an average weight of 144.6 ± 4.64 g were fed the experimental diets for 12wk. L-Lysine and DL-methionine were added to the diets containing 344 g kg-1 soybean meals at 22.02 and 12.94 g kg-1 of dry diet respectively. Significant higher weight gain, specific growth rate, protein efficiency ratio, condition factor, feed efficiency ratio, whole muscle protein and protein apparent digestibility were observed in fish fed soya protein-based diet supplemented with both lysine and methionine than that of fish of other dietary groups. There were no significant differences among fish fed diet supplemented with either methionine or lysine. Growth performances, feed utilization, carcass composition and apparent digestibility coefficients of protein, lipid and dry matter of fish fed control diet was significantly lower than those of fish fed diet supplemented both lysine and methionine and supplemented with either methionine or lysine. It can be concluded that beluga, fingerlings effectively utilize the supplemental amino acids (L-Lysine at 22.02 g kg-1 dry diet and DL-methionine at 12.94 g kg-1 dry diet) in the diets containing 344 g kg-1 soybean meals for better carcass proximate compositions, growth performance and feed efficiency and utilization
Total parenteral nutrition and carnitine supplementation practices in preterm neonates - results of a national survey
Thesis (M.A.)--Boston UniversityBackground: The goal of postnatal total parenteral nutrition (TPN) in premature neonates (PT) is to mimic the intrauterine environment of the fetus. Micronutrients are essential for optimal development. Although carnitine is present in human breast milk and is supplemented in infant formula, very preterm infants primarily receive parenteral nutrition, often devoid of carnitine, shortly after birth. Carnitine plays a critical role in cellular and mitochondrial metabolism. Preterm infants are deficient in carnitine as it is transferred from the placenta to the fetus during late pregnancy. Previously, our group surveyed US neonatologists in 2001 regarding carnitine supplementation practices and found that the majority were not fully familiar with the implications of carnitine deficiency and only 28% of preterm neonates on TPN were receiving carnitine. Since this study, recent research has emphasized the impact of carnitine on early weight gain and its neuroprotective effects.
Objective: To determine current TPN carnitine supplementation practices in fasting preterm neonates (< 32 wks and < 1,500g) by conducting a national survey of board- certified neonatologists. [TRUNCATED
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