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Sample records for dose increases leucine

  1. Supplementation of a suboptimal protein dose with leucine or essential amino acids: effects on myofibrillar protein synthesis at rest and following resistance exercise in men

    PubMed Central

    Churchward-Venne, Tyler A; Burd, Nicholas A; Mitchell, Cameron J; West, Daniel W D; Philp, Andrew; Marcotte, George R; Baker, Steven K; Baar, Keith; Phillips, Stuart M

    2012-01-01

    Leucine is a nutrient regulator of muscle protein synthesis by activating mTOR and possibly other proteins in this pathway. The purpose of this study was to examine the role of leucine in the regulation of human myofibrillar protein synthesis (MPS). Twenty-four males completed an acute bout of unilateral resistance exercise prior to consuming either: a dose (25 g) of whey protein (WHEY); 6.25 g whey protein with total leucine equivalent to WHEY (LEU); or 6.25 g whey protein with total essential amino acids (EAAs) equivalent to WHEY for all EAAs except leucine (EAA-LEU). Measures of MPS, signalling through mTOR, and amino acid transporter (AAT) mRNA abundance were made while fasted (FAST), and following feeding under rested (FED) and post-exercise (EX-FED) conditions. Leucinaemia was equivalent between WHEY and LEU and elevated compared to EAA-LEU (P = 0.001). MPS was increased above FAST at 1–3 h post-exercise in both FED (P < 0.001) and EX-FED (P < 0.001) conditions with no treatment effect. At 3–5 h, only WHEY remained significantly elevated above FAST in EX-FED (WHEY 184%vs. LEU 55% and EAA-LEU 35%; P = 0.036). AAT mRNA abundance was increased above FAST after feeding and exercise with no effect of leucinaemia. In summary, a low dose of whey protein supplemented with leucine or all other essential amino acids was as effective as a complete protein (WHEY) in stimulating postprandial MPS; however only WHEY was able to sustain increased rates of MPS post-exercise and may therefore be most suited to increase exercise-induced muscle protein accretion. PMID:22451437

  2. Leucine aminopeptidase - urine

    MedlinePlus

    Leucine aminopeptidase is a type of protein called an enzyme. It is normally found in liver cells ... Increased levels of leucine aminopeptidase can be seen in ... Hepatitis Liver cancer Liver ischemia (reduced blood flow to the ...

  3. Leucine supplementation of a low-protein meal increases skeletal muscle and visceral tissue protein synthesis in neonatal pigs by stimulating mTOR-dependent translation initiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Protein synthesis and eukaryotic initiation factor (eIF) activation are increased in skeletal muscle of neonatal pigs parenterally infused with amino acids. Leucine appears to be the most effective single amino acid to trigger these effects. To examine the response to enteral leucine supplementation...

  4. Hypoxia and Leucine Deprivation Induce Human Insulin-Like Growth Factor Binding Protein-1 Hyperphosphorylation and Increase Its Biological Activity

    PubMed Central

    Seferovic, Maxim D.; Ali, Rashad; Kamei, Hiroyasu; Liu, Suya; Khosravi, Javad M.; Nazarian, Steven; Han, Victor K. M.; Duan, Cunming; Gupta, Madhulika B.

    2009-01-01

    Fetal growth restriction is often caused by uteroplacental insufficiency that leads to fetal hypoxia and nutrient deprivation. Elevated IGF binding protein (IGFBP)-1 expression associated with fetal growth restriction has been documented. In this study we tested the hypothesis that hypoxia and nutrient deprivation induce IGFBP-1 phosphorylation and increase its biological potency in inhibiting IGF actions. HepG2 cells were subjected to hypoxia and leucine deprivation to mimic the deprivation of metabolic substrates. The total IGFBP-1 levels measured by ELISA were approximately 2- to 2.5-fold higher in hypoxia and leucine deprivation-treated cells compared with the controls. Two-dimensional immunoblotting showed that whereas the nonphosphorylated isoform is the predominant IGFBP-1 in the controls, the highly phosphorylated isoforms were dominant in hypoxia and leucine deprivation-treated cells. Liquid chromatography-tandem mass spectrometry analysis revealed four serine phosphorylation sites: three known sites (pSer 101, pSer 119, and pSer 169); and a novel site (pSer 98). Liquid chromatography-mass spectrometry was used to estimate the changes of phosphorylation upon treatment. Biacore analysis indicated that the highly phosphorylated IGFBP-1 isoforms found in hypoxia and leucine deprivation-treated cells had greater affinity for IGF-I [dissociation constant 5.83E (times 10 to the power)−10 m and 6.40E−09 m] relative to the IGFBP-1 from the controls (dissociation constant ∼1.54E−07 m). Furthermore, the highly phosphorylated IGFBP-1 had a stronger effect in inhibiting IGF-I-stimulated cell proliferation. These findings suggest that IGFBP-1 phosphorylation may be a novel mechanism of fetal adaptive response to hypoxia and nutrient restriction. PMID:18772238

  5. Chronic enteral leucine supplementation of a low protein diet increases skeletal muscle protein synthesis in neonatal pigs by stimulating mTOR-dependent translation initiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leucine appears to be the key amino acid that positively regulates mTOR signalling. We hypothesized that prolonged feeding (24 hours) of a Leu supplemented low protein (LP) diet in neonatal pigs will increase protein synthesis in skeletal muscle to a rate similar to that of a high protein diet (HP)....

  6. The combination of arginine and leucine supplementation of reduced crude protein diets for boars increases eating quality of pork.

    PubMed

    Madeira, M S; Alfaia, C M; Costa, P; Lopes, P A; Lemos, J P C; Bessa, R J B; Prates, J A M

    2014-05-01

    Fifty-four entire male pigs (Duroc × Pietrain × Large White × Landrace) from a commercial crossbred operation were used to investigate the effect of dietary Arg supplementation, protein reduction (PR), and Leu supplementation on performance, carcass traits, and meat quality. Pigs weighing 58.9 ± 1.6 kg BW were randomly assigned to 1 of 6 treatments (n = 9). The 6 dietary treatments were normal CP diet (16% CP, NPD), reduced CP diet (13% CP, RPD), reduced CP diet with Leu addition to 2.0% (RPDL), normal CP diet supplemented with 1% Arg (16% CP, Arg-NPD), reduced CP diet supplemented with 1% Arg (13% CP, Arg-RPD), and reduced CP diet with Leu addition to 2.0% and supplemented with 1% Arg (13% CP, Arg-RPDL). Pigs were slaughtered at 91.7 ± 1.6 kg BW. Dietary Arg supplementation had no effect on intramuscular fat (IMF) content but produced meat off-flavor and increased meat tenderness and overall acceptability. The PR increased (P < 0.001) IMF content (45% to 48%) but negatively affected the growth performance of pigs. In addition, PR increased (P < 0.05) back fat thickness and decreased loin weight. Leucine addition did not affect IMF content, back fat thickness, or loin weight. There was an increase of juiciness with PR and Leu addition, which accompanied the increase of IMF content with the low-CP diet. The PR increased meat deposition of 18:1c9, SFA, MUFA, and PUFA, which were not correlated with any pork sensory trait. The main combined effect of Arg was an increased tenderness and overall acceptability of pork. In conclusion, it was confirmed that dietary CP reduction enhances pork eating quality but negatively affects growth performance and carcass characteristics of pigs. PMID:24663178

  7. Increased occupational radiation doses: nuclear fuel cycle.

    PubMed

    Bouville, André; Kryuchkov, Victor

    2014-02-01

    The increased occupational doses resulting from the Chernobyl nuclear reactor accident that occurred in Ukraine in April 1986, the reactor accident of Fukushima that took place in Japan in March 2011, and the early operations of the Mayak Production Association in Russia in the 1940s and 1950s are presented and discussed. For comparison purposes, the occupational doses due to the other two major reactor accidents (Windscale in the United Kingdom in 1957 and Three Mile Island in the United States in 1979) and to the main plutonium-producing facility in the United States (Hanford Works) are also covered but in less detail. Both for the Chernobyl nuclear reactor accident and the routine operations at Mayak, the considerable efforts made to reconstruct individual doses from external irradiation to a large number of workers revealed that the recorded doses had been overestimated by a factor of about two.Introduction of Increased Occupational Exposures: Nuclear Industry Workers. (Video 1:32, http://links.lww.com/HP/A21). PMID:24378501

  8. Leucine aminopeptidase blood test

    MedlinePlus

    Serum leucine aminopeptidase ... Leucine aminopeptidase is a type of protein called an enzyme . This enzyme is normally found in cells ... check if your liver is damaged. Too much leucine aminopeptidase is released into your blood when you ...

  9. Deletion of internal structured repeats increases the stability of a leucine-rich repeat protein, YopM

    PubMed Central

    Barrick, Doug

    2011-01-01

    Mapping the stability distributions of proteins in their native folded states provides a critical link between structure, thermodynamics, and function. Linear repeat proteins have proven more amenable to this kind of mapping than globular proteins. C-terminal deletion studies of YopM, a large, linear leucine-rich repeat (LRR) protein, show that stability is distributed quite heterogeneously, yet a high level of cooperativity is maintained [1]. Key components of this distribution are three interfaces that strongly stabilize adjacent sequences, thereby maintaining structural integrity and promoting cooperativity. To better understand the distribution of interaction energy around these critical interfaces, we studied internal (rather than terminal) deletions of three LRRs in this region, including one of these stabilizing interfaces. Contrary to our expectation that deletion of structured repeats should be destabilizing, we find that internal deletion of folded repeats can actually stabilize the native state, suggesting that these repeats are destabilizing, although paradoxically, they are folded in the native state. We identified two residues within this destabilizing segment that deviate from the consensus sequence at a position that normally forms a stacked leucine ladder in the hydrophobic core. Replacement of these nonconsensus residues with leucine is stabilizing. This stability enhancement can be reproduced in the context of nonnative interfaces, but it requires an extended hydrophobic core. Our results demonstrate that different LRRs vary widely in their contribution to stability, and that this variation is context-dependent. These two factors are likely to determine the types of rearrangements that lead to folded, functional proteins, and in turn, are likely to restrict the pathways available for the evolution of linear repeat proteins. PMID:21764506

  10. Differential effects of leucine on translation initiation factor activation and protein synthesis in skeletal muscle, renal and adipose tissues of neonatal pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In adult rats, protein synthesis in skeletal muscle and adipose tissue increases in response to pharmacological doses of leucine (Leu) administered orally. In neonatal pigs, a physiological increase in plasma leucine stimulates protein synthesis in skeletal muscle without increasing hepatic protein...

  11. Anthocyanin excretion increases linearly with increasing strawberry dose.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A clinical study was conducted to investigate the dose response and metabolism of strawberry anthocyanins. In a crossover study design, twelve healthy adults consumed each of three strawberry treatments. The treatments were 100 g, 200 g, and 400 g of pureed strawberries, delivering 15 micromol, 30 m...

  12. Leucine aminopeptidase - urine

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003617.htm Leucine aminopeptidase - urine To use the sharing features on this page, please enable JavaScript. Leucine aminopeptidase is a type of protein called an ...

  13. Chronic leucine supplementation of a low protein diet increases protein synthesis in skeletal muscle and visceral tissues of neonatal pigs through mTOR signaling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leucine acutely stimulates protein synthesis by activating the mammalian target of rapamycin (mTOR) signaling pathway. We hypothesized that leucine supplementation of a low protein diet will enhance protein synthesis and mTOR signaling in the neonate for prolonged periods. Fasted 5-d-old pigs (n=6–8...

  14. Effect of very high dose D-leucine6-gonadotropin-releasing hormone proethylamide on the hypothalamic-pituitary testicular axis in patients with prostatic cancer.

    PubMed Central

    Warner, B; Worgul, T J; Drago, J; Demers, L; Dufau, M; Max, D; Santen, R J

    1983-01-01

    Potent synthetic analogs of gonadotropin-releasing hormone produce parodoxical antireproductive effects when administered chronically. These compounds are minimally toxic and may exhibit no plateau of the dose-response curve even at very high doses. These considerations served as the basis for our systematic evaluation of [D-leucine6-desarginine-glycine-NH2(10)]gonadotropin-releasing hormone (GnRH-A) proethylamide in the very high dose range (i.e., 10-fold larger amounts than previously used). In rats given the analog for 12 wk, prostate, testis, and seminal vesicle weights were suppressed to a greater extent with 200 micrograms q.d. than with 40 micrograms q.d. (P less than 0.01 prostate, less than 0.01 testis, less than 0.01 seminal vesicles), indicating dose-response effects in the very high dose range. 200 micrograms of [D-Leu6-des-Gly-NH2(10]-GnRH-A consistently suppressed leutinizing hormone (LH) values at 6 and 12 wk (basal 71 +/- 9.5; 6 wk 34 +/- 3.8; 12 wk 28 +/- 5 ng/ml) whereas 40 micrograms suppressed LH variably (basal 33 +/- 3.8; 6 wk 17 +/- 3.9; 12 wk 32 +/- 5.2). Testosterone fell to 15 +/- 2.4 and 19 +/- 2.0 ng/100 ml in response to 200 micrograms q.d. and to 27 +/- 6.4 and 22 +/- 7.4 ng/100 ml with the 40-micrograms dose. These findings in the rodent prompted treatment of stage D prostate cancer patients with similarly high doses of [D-Leu6-des-Gly-NH2(10)]-GnRH-A. After treatment for 11 wk with 1,000 or 10,000 micrograms/d of the analog, testosterone and dihydrotestosterone levels transiently rose and then fell into the surgically castrate range (testosterone 19 +/- 4.4 ng/100 ml [D-Leu6-des-Gly-NH2(10)]-GnRH-A vs. surgically castrate 11 +/- 0.9 ng/100 ml, P = NS; dihydrotestosterone 15 +/- 1.7 ng/100 ml GnRH-A vs. surgically castrate 15 +/- 4.1 ng/100 ml. P = NS). However, unlike the chronic stimulatory effect on the pituitary at lower doses, very high dose therapy resulted in profound suppression of plasma and urine LH. Plasma levels fell to

  15. Functional characterization of leucine transport induced in Xenopus laevis oocytes injected with mRNA isolated from midguts of lepidopteran larvae (Philosamia cynthia).

    PubMed

    Sacchi, V F; Perego, C; Magagnin, S

    1995-04-01

    The injection of poly(A)+ mRNA prepared from Philosamia cynthia midgut caused time- and dose-dependent increases of leucine transport in Xenopus laevis oocytes, with an increase in leucine uptake 1.5-3 times that of oocytes injected with water. When the NaCl concentration was reduced from 100 to 5 mmol l-1, the difference between mRNA- and water-injected oocytes was greater and a fourfold increase of L-leucine uptake was measured. D-Leucine (10 mmol l-1) completely inhibited the induced uptake of 0.1 mmol l-1 L-leucine. The newly expressed component of L-leucine uptake increased at alkaline pH and was abolished by incubation for 15 min with 15 mmol l-1 phenylglyoxal. The mean Km values, calculated using Na+ activation curves of leucine uptake, were 23.3 +/- 6.1 mmol l-1 in water-injected oocytes and 0.4 +/- 0.2 mmol l-1 for the newly expressed component of leucine uptake in mRNA-injected oocytes. On the basis of these results, we conclude that the increase of L-leucine uptake in mRNA-injected oocytes was due to the expression of a new transport system, which differs from the endogenous ones and shares many features with that found previously in Philosamia cynthia midgut. PMID:7730757

  16. Role of Insulin in the Regulation of Leucine Kinetics in the Conscious Dog

    PubMed Central

    Abumrad, Naji N.; Jefferson, L. S.; Rannels, S. R.; Williams, P. E.; Cherrington, A. D.; Lacy, W. W.

    1982-01-01

    To study the effect of insulin on leucine kinetics, three groups of conscious dogs were studied after an overnight fast (16-18 h). One, saline-infused group (n = 5), served as control. The other two groups were infused with somatostatin and constant replacement amount of glucagon; one group (n = 6) received no insulin replacement, to produce acute insulin deficiency, and the other (n = 6) was constantly replaced with 600 μU/kg per min insulin, to produce twice basal hyperinsulinemia. Hepatic and extrahepatic splanchnic (gut) balance of leucine and α-ketoisocaproate (KIC) were calculated using the arteriovenous difference technique. l,4,5,[3H]Leucine was used to measure the rates (micromoles per kilogram per minute) of appearance (Ra) and disappearance (Rd), and clearance (Cl) of plasma leucine (milliliters per kilogram per minute). Saline infusion for 7 h resulted in isotopic steady state, where Ra and Rd were equal (3.2±0.2 μmol/kg per min). Acute insulin withdrawal of 4-h duration caused the plasma leucine to increase by 40% (P < 0.005). This change was caused by a decrease in the outflow of leucine (Cl) from the plasma, since Ra did not change. The net hepatic release of the amino acid (0.24±0.03 μmol/kg per min) did not change significantly; the arterio-deep femoral venous differences of leucine (−10±1 μmol/liter) and KIC (−12±2 μmol/liter) did not change significantly indicating net release of the amino and ketoacids across the hindlimb. Selective twice basal hyperinsulinemia resulted in a 36% drop in plasma leucine (from control levels of 128±8 to 82±7 μmol/liter, P < 0.005) within 4 h. This was accompanied by a 15% reduction in Ra and a 56% rise in clearance (P < 0.001, both). Net hepatic leucine production and net release of leucine and KIC across the hindlimb fell markedly. These studies indicate that physiologic changes in circulating insulin levels result in a differential dose-dependent effect on total body leucine metabolism in the

  17. N-acetyl-L-leucine accelerates vestibular compensation after unilateral labyrinthectomy by action in the cerebellum and thalamus.

    PubMed

    Günther, Lisa; Beck, Roswitha; Xiong, Guoming; Potschka, Heidrun; Jahn, Klaus; Bartenstein, Peter; Brandt, Thomas; Dutia, Mayank; Dieterich, Marianne; Strupp, Michael; la Fougère, Christian; Zwergal, Andreas

    2015-01-01

    An acute unilateral vestibular lesion leads to a vestibular tone imbalance with nystagmus, head roll tilt and postural imbalance. These deficits gradually decrease over days to weeks due to central vestibular compensation (VC). This study investigated the effects of i.v. N-acetyl-DL-leucine, N-acetyl-L-leucine and N-acetyl-D-leucine on VC using behavioural testing and serial [18F]-Fluoro-desoxyglucose ([18F]-FDG)-μPET in a rat model of unilateral chemical labyrinthectomy (UL). Vestibular behavioural testing included measurements of nystagmus, head roll tilt and postural imbalance as well as sequential whole-brain [18F]-FDG-μPET was done before and on days 1,3,7 and 15 after UL. A significant reduction of postural imbalance scores was identified on day 7 in the N-acetyl-DL-leucine (p < 0.03) and the N-acetyl-L-leucine groups (p < 0.01), compared to the sham treatment group, but not in the N-acetyl-D-leucine group (comparison for applied dose of 24 mg i.v. per rat, equivalent to 60 mg/kg body weight, in each group). The course of postural compensation in the DL- and L-group was accelerated by about 6 days relative to controls. The effect of N-acetyl-L-leucine on postural compensation depended on the dose: in contrast to 60 mg/kg, doses of 15 mg/kg and 3.75 mg/kg had no significant effect. N-acetyl-L-leucine did not change the compensation of nystagmus or head roll tilt at any dose. Measurements of the regional cerebral glucose metabolism (rCGM) by means of μPET revealed that only N-acetyl-L-leucine but not N-acetyl-D-leucine caused a significant increase of rCGM in the vestibulocerebellum and a decrease in the posterolateral thalamus and subthalamic region on days 3 and 7. A similar pattern was found when comparing the effect of N-acetyl-L-leucine on rCGM in an UL-group and a sham UL-group without vestibular damage. In conclusion, N-acetyl-L-leucine improves compensation of postural symptoms after UL in a dose-dependent and specific manner, most likely by

  18. N-Acetyl-L-Leucine Accelerates Vestibular Compensation after Unilateral Labyrinthectomy by Action in the Cerebellum and Thalamus

    PubMed Central

    Xiong, Guoming; Potschka, Heidrun; Jahn, Klaus; Bartenstein, Peter; Brandt, Thomas; Dutia, Mayank; Dieterich, Marianne; Strupp, Michael; la Fougère, Christian; Zwergal, Andreas

    2015-01-01

    An acute unilateral vestibular lesion leads to a vestibular tone imbalance with nystagmus, head roll tilt and postural imbalance. These deficits gradually decrease over days to weeks due to central vestibular compensation (VC). This study investigated the effects of i.v. N-acetyl-DL-leucine, N-acetyl-L-leucine and N-acetyl-D-leucine on VC using behavioural testing and serial [18F]-Fluoro-desoxyglucose ([18F]-FDG)-μPET in a rat model of unilateral chemical labyrinthectomy (UL). Vestibular behavioural testing included measurements of nystagmus, head roll tilt and postural imbalance as well as sequential whole-brain [18F]-FDG-μPET was done before and on days 1,3,7 and 15 after UL. A significant reduction of postural imbalance scores was identified on day 7 in the N-acetyl-DL-leucine (p < 0.03) and the N-acetyl-L-leucine groups (p < 0.01), compared to the sham treatment group, but not in the N-acetyl-D-leucine group (comparison for applied dose of 24 mg i.v. per rat, equivalent to 60 mg/kg body weight, in each group). The course of postural compensation in the DL- and L-group was accelerated by about 6 days relative to controls. The effect of N-acetyl-L-leucine on postural compensation depended on the dose: in contrast to 60 mg/kg, doses of 15 mg/kg and 3.75 mg/kg had no significant effect. N-acetyl-L-leucine did not change the compensation of nystagmus or head roll tilt at any dose. Measurements of the regional cerebral glucose metabolism (rCGM) by means of μPET revealed that only N-acetyl-L-leucine but not N-acetyl-D-leucine caused a significant increase of rCGM in the vestibulocerebellum and a decrease in the posterolateral thalamus and subthalamic region on days 3 and 7. A similar pattern was found when comparing the effect of N-acetyl-L-leucine on rCGM in an UL-group and a sham UL-group without vestibular damage. In conclusion, N-acetyl-L-leucine improves compensation of postural symptoms after UL in a dose-dependent and specific manner, most likely by

  19. Leucine metabolism in patients with Hepatic Encephalopathy

    SciTech Connect

    McGhee, A.S.; Kassouny, M.E.; Matthews, D.E.; Millikan, W.

    1986-03-01

    A primed continuous infusion of (/sup 15/N, 1-/sup 13/C)leucine was used to determine whether increased oxidation and/or protein synthesis of leucine occurs in patients with cirrhosis. Five controls and patients were equilibrated on a metabolic balance diet (0.6 g protein per kg ideal body weight (IBW)). An additional four patients were equilibrated in the same manner with the same type of diet with a protein level of 0.75 g per kg IBW. Plasma leucine and breath CO/sub 2/ enrichments were measured by mass spectrometry. Protein synthesis and leucine metabolism were identical in controls and patients when both were fed a diet with 0.6 g protein/kg IBW. Results indicate that systemic derangements of leucine metabolism are not the cause of Hepatic Encephalopathy.

  20. LEUCINE STIMULATION OF SKELETAL MUSCLE PROTEIN SYNTHESIS DURING PROLONGED LEUCINE INFUSION IS DEPENDENT ON AMINO ACID AVAILABILITY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leucine stimulates protein synthesis in cultured cells, mature rats and neonatal pigs. We have reported that leucine infusion increases protein synthesis in skeletal muscle of neonatal pigs during a 60-min infusion. When leucine infusion was prolonged for 120 min, however, protein synthesis was no...

  1. Multilateral analysis of increasing collective dose and new ALARA programme.

    PubMed

    Oumi, Tadashi; Morii, Yasuki; Imai, Toshirou

    2011-07-01

    JAPC (The Japan Atomic Power Company) is the only electric power company that operates different types of nuclear reactors in Japan; it operates two BWRs (boiling water reactors), one pressurised water reactor and one gas cooled reactor. JAPC has been conducting various activities aimed at reducing radiation dose received by workers for over 45 y. Recently, the collective dose resulting from periodic maintenance has increased at each plant because of the replacement of large equipment and the unexpected extension of the outage period. In particular, the collective dose at Tokai-2 is one of the highest among Japanese BWR plants((1)), owing to the replacement and strengthening of equipment to meet earthquake-proof requirements. In this study, the authors performed a multilateral analysis of unacceptably a large collective dose and devised a new ALARA programme that includes a 3D dose prediction map and the development of machines to assist workers. PMID:21652597

  2. Does administering iodine in radiological procedures increase patient doses?

    SciTech Connect

    He, Wenjun; Yao, Hai; Huda, Walter; Mah, Eugene

    2014-11-01

    Purpose: The authors investigated the changes in the pattern of energy deposition in tissue equivalent phantoms following the introduction of iodinated contrast media. Methods: The phantom consisted of a small “contrast sphere,” filled with water or iodinated contrast, located at the center of a 28 cm diameter water sphere. Monte Carlo simulations were performed using MCNP5 codes, validated by simulating irradiations with analytical solutions. Monoenergetic x-rays ranging from 35 to 150 keV were used to simulate exposures to spheres containing contrast agent with iodine concentrations ranging from 1 to 100 mg/ml. Relative values of energy imparted to the contrast sphere, as well as to the whole phantom, were calculated. Changes in patterns of energy deposition around the contrast sphere were also investigated. Results: Small contrast spheres can increase local absorbed dose by a factor of 13, but the corresponding increase in total energy absorbed was negligible (<1%). The highest localized dose increases were found to occur at incident photon energies of about 60 keV. For a concentration of about 10 mg/ml, typical of clinical practice, localized absorbed doses were generally increased by about a factor of two. At this concentration of 10 mg/ml, the maximum increase in total energy deposition in the phantom was only 6%. These simulations demonstrated that increases in contrast sphere doses were offset by corresponding dose reductions at distal and posterior locations. Conclusions: Adding iodine can result in values of localized absorbed dose increasing by more than an order of magnitude, but the total energy deposition is generally very modest (i.e., <10%). Their data show that adding iodine primarily changes the pattern of energy deposition in the irradiated region, rather than increasing patient doses per se.

  3. Enteral leucine supplementation increases protein synthesis in skeletal and cardiac muscles and visceral tissues of neonatal pigs through mTORC1-dependent pathways

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leucine activates mammalian target of rapamycin (mTOR) to upregulate protein synthesis (PS). To examine enteral Leu effects on PS and signaling activation, 5-d-old piglets were fed for 24 h diets containing: (i) LP, (ii) LP+L, or (iii) HP. PS in skeletal muscles, heart, liver, pancreas, and jejunum...

  4. Leucine supplementation of an infant formula increases skeletal muscle and visceral tissue protein synthesis in a neonatal animal model by stimulating mTOR-dependent translation initiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Low birth weight infants are often discharged weighing less than the tenth percentile for age and some remain small to adulthood with adverse long-term outcomes related to inadequate nutrition. Infant formula fortifiers had been used to improve the nutritional value of milk formulas. Leucine (Leu) a...

  5. Leucine in Obesity: Therapeutic Prospects.

    PubMed

    Yao, Kang; Duan, Yehui; Li, Fengna; Tan, Bie; Hou, Yongqing; Wu, Guoyao; Yin, Yulong

    2016-08-01

    Obesity develops from an imbalance of energy homeostasis and is associated with chronic low-grade inflammation in white adipose tissues (WAT). Inflammation is involved in the pathophysiology of many obesity-induced disorders including insulin resistance and diabetes. Increasing evidence has shown that dietary leucine supplementation positively affects the parameters associated with obesity and obesity-related metabolic disorders. The beneficial effects include increased loss of body weight, reduced WAT inflammation, improved lipid and glucose metabolism, enhanced mitochondrial function, and preserved lean body mass. Although these beneficial effects have not been clearly established, dietary leucine supplementation, either alone or as part of a therapeutic regimen, may be a good nutritional tool in the prevention and management of obesity and obesity-induced metabolic disorders. PMID:27256112

  6. Compartmental model of leucine kinetics in humans.

    PubMed

    Cobelli, C; Saccomani, M P; Tessari, P; Biolo, G; Luzi, L; Matthews, D E

    1991-10-01

    The complexity of amino acid and protein metabolism has limited the development of comprehensive, accurate whole body kinetic models. For leucine, simplified approaches are in use to measure in vivo leucine fluxes, but their domain of validity is uncertain. We propose here a comprehensive compartmental model of the kinetics of leucine and alpha-ketoisocaproate (KIC) in humans. Data from a multiple-tracer administration were generated with a two-stage (I and II) experiment. Six normal subjects were studied. In experiment I, labeled leucine and KIC were simultaneously injected into plasma. Four plasma leucine and KIC tracer concentration curves and label in the expired CO2 were measured. In experiment II, labeled bicarbonate was injected into plasma, and labeled CO2 in the expired air was measured. Radioactive (L-[1-14C]leucine, [4,5-3H]KIC, [14C]bicarbonate) and stable isotope (L-[1-13C]leucine, [5,5,5-2H3]KIC, [13C]bicarbonate) tracers were employed. The input format was a bolus (impulse) dose in the radioactive case and a constant infusion in the stable isotope case. A number of physiologically based, linear time-invariant compartmental models were proposed and tested against the data. The model finally chosen for leucine-KIC kinetics has 10 compartments: 4 for leucine, 3 for KIC, and 3 for bicarbonate. The model is a priori uniquely identifiable, and its parameters were estimated with precision from the five curves of experiment I. The separate assessment of bicarbonate kinetics (experiment II) was shown to be unnecessary. The model defines masses and fluxes of leucine in the organism, in particular its intracellular appearance from protein breakdown, its oxidation, and its incorporation into proteins. An important feature of the model is its ability to estimate leucine oxidation by resolving the bicarbonate model in each individual subject. Finally, the model allows the assessment of the domain of validity of the simpler commonly used models. PMID:1928344

  7. Organized Pneumonia Secondary to Increasing Doses of Temozolomide

    PubMed Central

    Consuegra Vanegas, Angélica; Matachana Martínez, María; Cordero Lorenzana, Lourdes; Vidal García, Iria; Montero Martínez, Carmen

    2015-01-01

    Surgery, radiotherapy (RT), and chemotherapy have a role in the control of tumor growth, progression, and recurrence in high-grade gliomas. Temozolomide has been incorporated as the main chemotherapy agent for managing these tumors. Here, we present a case of a patient who developed a severe organizing pneumonia after increasing doses of temozolomide for a high-grade glioma. PMID:26487994

  8. Increasing the dose of varenicline in patients who do not respond to the standard dose.

    PubMed

    Jiménez-Ruiz, Carlos A; Barrios, Malena; Peña, Sandra; Cicero, Ana; Mayayo, Marisa; Cristóbal, Maribel; Perera, Lidia

    2013-12-01

    Varenicline is a partial agonist of α4β2 nicotinic acetylcholine receptors. It is effective at dosages of 2 mg/d for 12 weeks, but not for all smokers. It is possible that increasing the dose can increase the drug efficacy. We reviewed the clinical records of consecutive smokers who had been treated in 2 smoking cessation services with varenicline at doses of 3 mg/d. In all cases, the treatment program consisted of a combination of behavioral therapy and drug treatment. Varenicline was prescribed at a standard dosage for 8 weeks. After 8 weeks of treatment, the dose was increased to 3 mg/d if patients tolerated varenicline well and continued smoking or, in spite of not smoking, if they experienced severe withdrawal symptoms. The sample included 73 patients, of whom 52 continued to smoke at 8 weeks and 21 stopped smoking but reported severe withdrawal discomfort. Carbon monoxide-validated continuous abstinence rates from week 9 to week 24 were 40% and 48% in these 2 subgroups, respectively. The increase in dosage was associated with adverse events in 22 patients (30%). These were mostly mild and included nausea, vomiting, abnormal dreams, and insomnia. Only 2 patients discontinued treatment (both because of nausea and vomiting). Thus, we conclude that increasing the varenicline dose in smokers who do not respond to the standard dose after 8 weeks of treatment is associated with limited adverse events and high success rates. PMID:24290118

  9. Potent anti-seizure effects of D-leucine.

    PubMed

    Hartman, Adam L; Santos, Polan; O'Riordan, Kenneth J; Stafstrom, Carl E; Hardwick, J Marie

    2015-10-01

    There are no effective treatments for millions of patients with intractable epilepsy. High-fat ketogenic diets may provide significant clinical benefit but are challenging to implement. Low carbohydrate levels appear to be essential for the ketogenic diet to work, but the active ingredients in dietary interventions remain elusive, and a role for ketogenesis has been challenged. A potential antiseizure role of dietary protein or of individual amino acids in the ketogenic diet is understudied. We investigated the two exclusively ketogenic amino acids, L-leucine and L-lysine, and found that only L-leucine potently protects mice when administered prior to the onset of seizures induced by kainic acid injection, but not by inducing ketosis. Unexpectedly, the D-enantiomer of leucine, which is found in trace amounts in the brain, worked as well or better than L-leucine against both kainic acid and 6Hz electroshock-induced seizures. However, unlike L-leucine, D-leucine potently terminated seizures even after the onset of seizure activity. Furthermore, D-leucine, but not L-leucine, reduced long-term potentiation but had no effect on basal synaptic transmission in vitro. In a screen of candidate neuronal receptors, D-leucine failed to compete for binding by cognate ligands, potentially suggesting a novel target. Even at low doses, D-leucine suppressed ongoing seizures at least as effectively as diazepam but without sedative effects. These studies raise the possibility that D-leucine may represent a new class of anti-seizure agents, and that D-leucine may have a previously unknown function in eukaryotes. PMID:26054437

  10. Pathology effects at radiation doses below those causing increased mortality

    NASA Technical Reports Server (NTRS)

    Carnes, Bruce A.; Gavrilova, Natalia; Grahn, Douglas

    2002-01-01

    Mortality data from experiments conducted at the Argonne National Laboratory (ANL) on the long-term effects of external whole-body irradiation on B6CF(1) mice were used to investigate radiation-induced effects at intermediate doses of (60)Co gamma rays or fission-spectrum neutrons either delivered as a single exposure or protracted over 60 once-weekly exposures. Kaplan-Meier analyses were used to identify the lowest dose in the ANL data (within radiation quality, pattern of exposure, and sex) at which radiation-induced mortality caused by primary tumors could be detected (approximately 1-2 Gy for gamma rays and 10-15 cGy for neutrons). Doses at and below these levels were then examined for radiation-induced shifts in the spectrum of pathology detected at death. To do this, specific pathology events were pooled into larger assemblages based on whether they were cancer, cardiovascular disease or non-neoplastic diseases detected within the lungs and pleura, liver and biliary tract, reproductive organs, or urinary tract. Cancer and cardiovascular disease were further subdivided into categories based on whether they caused death, contributed to death, or were simply observed at death. Counts of how often events falling within each of these combined pathology categories occurred within a mouse were then used as predictor variables in logistic regression to determine whether irradiated mice could be distinguished from control mice. Increased pathology burdens were detected in irradiated mice at doses lower than those causing detectable shifts in mortality-22 cGy for gamma rays and 2 cGy for neutrons. These findings suggest that (1) models based on mortality data alone may underestimate radiation effects, (2) radiation may have adverse health consequences (i.e. elevated health risks) even when mortality risks are not detected, and (3) radiation-induced pathologies other than cancer do occur, and they involve multiple organ systems.

  11. Increased radiation dose at mammography due to prolonged exposure, delayed processing, and increased film darkening

    SciTech Connect

    Kimme-Smith, C.; Bassett, L.W.; Gold, R.H.; Chow, S. )

    1991-02-01

    Four single-emulsion films introduced over the past 2 years--Du Pont Microvision, Fuji MiMa, Konica CM, and Eastman Kodak OM--were compared with Eastman Kodak OM SO-177 (Min-RE) film to evaluate their varying effects on mean glandular dose of reciprocity law failure due to prolonged exposure, delayed processing, and increased film darkening as a result of increased radiation exposure to improve penetration of glandular tissue. Exposures over 1.3 seconds led to increased radiation doses of 20%-30%. Delays in processing of 6 hours decreased processing speed by 11%-32% for all films except Du Pont Microvision. Optical density increases of 0.40 required 20%-30% more skin exposure for all five films. Optimal viewing densities were also evaluated and found to be different for each of the five films. Mammographers need to be aware of these differences in mammographic films to achieve maximum contrast at mammography.

  12. Leucine metabolism in human newborns

    SciTech Connect

    Denne, S.C.; Kalhan, S.C. )

    1987-12-01

    The present study was designed to (1) determine whether a relationship exists between newborn birth weight and leucine metabolism and (2) compare leucine and energy metabolism in a period of rapid growth and development (i.e., newborn) with a constant nongrowth period (i.e., adult). Leucine kinetics and energy expenditure were measured in the postabsorptive state in 12 normal full-term newborns in early neonatal life and in 11 normal adults using a primed constant L-(1-{sup 13}C)leucine infusion combined with respiratory calorimetry. A significant positive correlation between newborn birth weight and leucine flux was observed. These data suggest the following. (1) A relationship exists between newborn birth weight and protein metabolism, as reflected by the correlation between leucine flux when expressed as micromoles per kilogram per hour and birth weight. (2) The high rate of leucine flux measured in newborns probably reflects the rapid remodeling of protein that occurs in this period of development, even during fasting. (3) The similar values in newborns and adults of leucine kinetics and energy expenditure when normalized to metabolic body weight and the nearly equivalent allometric exponents relating body weight to leucine flux and energy expenditure support a close relationship between leucine and energy metabolism, at least at the extremes of human growth.

  13. Stimulating effects of inosine, uridine and glutamine on the tissue distribution of radioactive D-leucine in tumor bearing mice.

    PubMed

    Goto, R; Takeda, A; Tamemasa, O; Chaney, J E; Digenis, G A

    1984-02-01

    This experiment was carried out in search for stimulators of the in vivo uptake of D- and L-leucine by tumor and pancreas for the possible application to gamma-emitter labeled amino acids in nuclear medical diagnosis. Inosine, uridine, and glutamine which are stimulators of the in vitro incorporation of radioactive L-amino acids into some tumor cells significantly enhanced the uptake of D-leucine into the pancreas, while in Ehrlich solid tumor only a little if any increase was observed. Of the compounds tested inosine showed the highest stimulation of pancreas uptake in the range of doses used, resulting in the best pancreas-to-liver concentration ratio, a factor of significant consideration for pancreas imaging. The uptake of L-leucine by the tumor and pancreas was little affected by these compounds. PMID:6739860

  14. Leucine metabolism in stable cirrhosis.

    PubMed

    Mullen, K D; Denne, S C; McCullough, A J; Savin, S M; Bruno, D; Tavill, A S; Kalhan, S C

    1986-01-01

    Alterations in protein and amino acid metabolism have been postulated to explain the frequent observations of muscle wasting and decreased plasma branched-chain amino acid concentrations in cirrhosis. In order to investigate the changes in protein metabolism, we have measured the rates of leucine turnover and oxidation in six stable, biopsy-proven cirrhotics and six age and sex-matched healthy control subjects after an overnight fast, using [1-13C]leucine tracer. Following a primed constant-rate infusion of [1-13C]leucine, the 13C enrichments of plasma leucine and expired CO2 were used to estimate leucine turnover and oxidation, respectively. Fat-free body mass was estimated from the measurements of total body water as quantified by H2[18O] tracer dilution. The rates of CO2 production and oxygen consumption were measured hourly during the study period, using open-circuit respiratory calorimetry. Urinary urea, ammonia and total nitrogen excretion rates were quantified from timed urine samples. Even though the plasma leucine levels were lower in cirrhotics as compared with controls (100.5 +/- 17.1 vs. 138.3 +/- 20.4 mumoles per liter, mean +/- S.D., p less than 0.001), the rates of leucine turnover were not significantly different in the two groups (89.4 +/- 19.0 vs. 87.8 +/- 19.0 mumoles per kg X hr). In contrast, the rates of leucine oxidation were significantly reduced in cirrhosis (8.1 +/- 2.5 vs. 12.7 +/- 3.1 mumoles per kg X hr, p less than 0.01). When all subjects were considered, the leucine oxidation rate was correlated with plasma leucine concentration (r = 0.62, p less than 0.03).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3089896

  15. Relationship between surface concentration of L-leucine and bulk powder properties in spray dried formulations.

    PubMed

    Mangal, Sharad; Meiser, Felix; Tan, Geoffrey; Gengenbach, Thomas; Denman, John; Rowles, Matthew R; Larson, Ian; Morton, David A V

    2015-08-01

    The amino acid L-leucine has been demonstrated to act as a lubricant and improve the dispersibility of otherwise cohesive fine particles. It was hypothesized that optimum surface L-leucine concentration is necessary to achieve optimal surface and bulk powder properties. Polyvinylpyrrolidone was spray dried with different concentration of L-leucine and the change in surface composition of the formulations was determined using X-ray photoelectron spectroscopy (XPS) and time of flight-secondary ion mass spectrometry (ToF-SIMS). The formulations were also subjected to powder X-ray diffraction analysis in order to understand the relationship between surface concentration and solid-state properties of L-leucine. In addition, the morphology, surface energy and bulk cohesion of spray dried formulations were also assessed to understand the relation between surface L-leucine concentration and surface and bulk properties. The surface concentration of L-leucine increased with higher feed concentrations and plateaued at about 10% L-leucine. Higher surface L-leucine concentration also resulted in the formation of larger L-leucine crystals and not much change in crystal size was noted above 10% L-leucine. A change in surface morphology of particles from spherical to increasingly corrugated was also observed with increasing surface l-leucine concentration. Specific collapsed/folded over particles were only seen in formulations with 10% or higher l-leucine feed concentration suggesting a change in particle surface formation process. In addition, bulk cohesion also reduced and approached a minimum with 10% L-leucine concentration. Thus, the surface concentration of L-leucine governs particle formation and optimum surface L-leucine concentration results in optimum surface and bulk powder properties. PMID:26007290

  16. Leucine Supplementation Improves Acquired Growth Hormone Resistance in Rats with Protein-Energy Malnutrition

    PubMed Central

    Wang, Xinying; Zhao, Jie; Wan, Xiao; Zhang, Li; Wu, Chao; Li, Ning; Li, Jieshou

    2015-01-01

    Background Protein-energy malnutrition (PEM) can lead to growth hormone (GH) resistance. Leucine supplementation diets have been shown to increase protein synthesis in muscles. Our study aimed at investigating if long-term leucine supplementation could modulate GH-insulin-like growth factor (IGF)-1 system function and mammalian target of rapamycin (mTOR)-related signal transduction in skeletal muscles in a rat model of severe malnutrition. Methodology/Principal Findings Male Sprague-Dawley rats (n = 50; weight, 302 ± 5 g) were divided into 5 treatment groups, including 2 control groups (a normal control group that was fed chow and ad libitum water [CON, n = 10] and a malnourished control group [MC, n = 10] that was fed a 50% chow diet). After undergoing a weight loss stage for 4 weeks, rats received either the chow diet (MC-CON, n = 10), the chow diet supplemented with low-dose leucine (MC-L, n = 10), or the chow diet supplemented with high-dose leucine (MC-H, n = 10) for 2 weeks. The muscle masses of the gastrocnemius, soleus, and extensor digitorum longus were significantly reduced in the MC group. Re-feeding increased muscle mass, especially in the MC-L and MC-H groups. In the MC group, serum IGF-1, IGF-binding protein (IGFBP)-3, and hepatic growth hormone receptor (GHR) levels were significantly decreased and phosphorylation of the downstream anabolic signaling effectors protein kinase B (Akt), mTOR, and ribosomal protein S6 kinase 1 (S6K1) were significantly lower than in other groups. However, serum IGF-1 and IGF binding protein (IGFBP)-3 concentrations and hepatic growth hormone receptor (GHR) levels were significantly higher in the MC-L and MC-H groups than in the MC-CON group, and serum IGFBP-1 levels was significantly reduced in the MC-L and MC-H groups. These changes were consistent with those observed for hepatic mRNA expression levels. Phosphorylation of the downstream anabolic signaling effectors Akt, mTOR, and S6K1 were also significantly higher in

  17. L-Leucine prevents ammonia-induced changes in glutamate receptors in the brain and in visual evoked potentials in the rabbit.

    PubMed

    Ferenci, P; Pappas, C S; Jones, E A

    1984-01-01

    The effect of L-leucine on glutamate receptors in the brain and on visual evoked potentials was studied in hyperammonemic rabbits. Hyperammonemia was induced by the iv infusion of 2.1 mmol NH4Cl/h over 3 hr. Hyperammonemia was followed by a 116% increase in the specific binding of 3H-glutamate to synaptic membranes prepared from the hippocampus. This increase was due to both an increase in the affinity and in the density of the glutamate receptor. The simultaneous infusion of L-leucine (6.7 mmol/hr) completely prevented the ammonia-induced increase in the specific glutamate binding, whereas L-valine and D-leucine had no effect. Hyperammonemia was also associated with typical, reproducible, and reversible changes in visual evoked potentials. The amplitudes of the first negative and the second positive peak decreased, whereas the latencies of these peaks remained unchanged. The simultaneous infusion of L-leucine completely prevented these changes. These findings indicate (1) that L-leucine prevents ammonia-induced changes in the glutamatergic excitatory neurotransmitter system and (2) that pharmacologic doses of L-leucine modulate the effects of hyperammonemia on central neurotransmission as assessed by visual evoked potentials. A causal relationship between the effects of L-leucine on ammonia-induced changes in glutamate receptors and in visual evoked potentials cannot be inferred with confidence. These findings provide a potential alternative explanation for the apparent beneficial effects of infusions of branched-chain amino acids on hepatic encephalography in patients with chronic liver disease. PMID:6151602

  18. Leucine Metabolism in T Cell Activation: mTOR Signaling and Beyond.

    PubMed

    Ananieva, Elitsa A; Powell, Jonathan D; Hutson, Susan M

    2016-07-01

    In connection with the increasing interest in metabolic regulation of the immune response, this review discusses current advances in understanding the role of leucine and leucine metabolism in T lymphocyte (T cell) activation. T cell activation during the development of an immune response depends on metabolic reprogramming to ensure that sufficient nutrients and energy are taken up by the highly proliferating T cells. Leucine has been described as an important essential amino acid and a nutrient signal that activates complex 1 of the mammalian target of rapamycin (mTORC1), which is a critical regulator of T cell proliferation, differentiation, and function. The role of leucine in these processes is further discussed in relation to amino acid transporters, leucine-degrading enzymes, and other metabolites of leucine metabolism. A new model of T cell regulation by leucine is proposed and outlines a chain of events that leads to the activation of mTORC1 in T cells. PMID:27422517

  19. Structural basis for leucine sensing by the Sestrin2-mTORC1 pathway

    PubMed Central

    Saxton, Robert A.; Knockenhauer, Kevin E.; Wolfson, Rachel L.; Chantranupong, Lynne; Pacold, Michael E.; Wang, Tim; Schwartz, Thomas U.; Sabatini, David M.

    2015-01-01

    Eukaryotic cells coordinate growth with the availability of nutrients through mTOR complex 1 (mTORC1), a master growth regulator. Leucine is of particular importance and activates mTORC1 via the Rag GTPases and their regulators GATOR1 and GATOR2. Sestrin2 interacts with GATOR2 and is a leucine sensor. We present the 2.7-Å crystal structure of Sestrin2 in complex with leucine. Leucine binds through a single pocket that coordinates its charged functional groups and confers specificity for the hydrophobic side chain. A loop encloses leucine and forms a lid-latch mechanism required for binding. A structure-guided mutation in Sestrin2 that decreases its affinity for leucine leads to a concomitant increase in the leucine concentration required for mTORC1 activation in cells. These results provide a structural mechanism of amino acid sensing by the mTORC1 pathway. PMID:26586190

  20. Leucine supplementation improves regeneration of skeletal muscles from old rats.

    PubMed

    Pereira, Marcelo G; Silva, Meiricris T; da Cunha, Fernanda M; Moriscot, Anselmo S; Aoki, Marcelo S; Miyabara, Elen H

    2015-12-01

    The decreased regenerative capacity of old skeletal muscles involves disrupted turnover of proteins. This study investigated whether leucine supplementation in old rats could improve muscle regenerative capacity. Young and old male Wistar rats were supplemented with leucine; then, the muscles were cryolesioned and examined after 3 and 10 days. Leucine supplementation attenuated the decrease in the expression of eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1) and eukaryotic translation initiation factor 4E (eIF4E) in young and old muscles on day 3 post-injury and promoted an increase in the cross-sectional area of regenerating myofibers from both young and old soleus muscles on day 10 post-injury. This supplementation decreased the levels of ubiquitinated proteins and increased the proteasome activity in young regenerating muscles, but the opposite effect was observed in old regenerating muscles. Moreover, leucine decreased the inflammation area and induced an increase in the number of proliferating satellite cells in both young and old muscles. Our results suggest that leucine supplementation improves the regeneration of skeletal muscles from old rats, through the preservation of certain biological responses upon leucine supplementation. Such responses comprise the decrease in the inflammation area, increase in the number of proliferating satellite cells and size of regenerating myofibers, combined with the modulation of components of the phosphoinositide 3-kinase/Akt-protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway and ubiquitin-proteasome system. PMID:26481769

  1. Deletion of the PH-domain and Leucine-rich Repeat Protein Phosphatase 1 (Phlpp1) Increases Fibroblast Growth Factor (Fgf) 18 Expression and Promotes Chondrocyte Proliferation*

    PubMed Central

    Bradley, Elizabeth W.; Carpio, Lomeli R.; Newton, Alexandra C.; Westendorf, Jennifer J.

    2015-01-01

    Endochondral ossification orchestrates formation of the vertebrate skeleton and is often induced during disease and repair processes of the musculoskeletal system. Here we show that the protein phosphatase Phlpp1 regulates endochondral ossification. Phlpp1 null mice exhibit decreased bone mass and notable changes in the growth plate, including increased BrdU incorporation and matrix production. Phosphorylation of known Phlpp1 substrates, Akt2, PKC, and p70 S6 kinase, were enhanced in ex vivo cultured Phlpp1−/− chondrocytes. Furthermore, Phlpp1 deficiency diminished FoxO1 levels leading to increased expression of Fgf18, Mek/Erk activity, and chondrocyte metabolic activity. Phlpp inhibitors also increased matrix content, Fgf18 production and Erk1/2 phosphorylation. Chemical inhibition of Fgfr-signaling abrogated elevated Erk1/2 phosphorylation and metabolic activity in Phlpp1-null cultures. These results demonstrate that Phlpp1 controls chondrogenesis via multiple mechanisms and that Phlpp1 inhibition could be a strategy to promote cartilage regeneration and repair. PMID:25953896

  2. CYP2D6 genotype- and endoxifen-guided tamoxifen dose escalation increases endoxifen serum concentrations without increasing side effects.

    PubMed

    Dezentjé, V O; Opdam, F L; Gelderblom, H; Hartigh den, J; Van der Straaten, T; Vree, R; Maartense, E; Smorenburg, C H; Putter, H; Dieudonné, A S; Neven, P; Van de Velde, C J H; Nortier, J W R; Guchelaar, H-J

    2015-10-01

    Breast cancer patients with absent or reduced CYP2D6 activity and consequently low endoxifen levels may benefit less from tamoxifen treatment. CYP2D6 poor and intermediate metabolizers may need a personalized increased tamoxifen dose to achieve effective endoxifen serum concentrations, without increasing toxicity. From a prospective study population of early breast cancer patients using tamoxifen (CYPTAM: NTR1509), 12 CYP2D6 poor and 12 intermediate metabolizers were selected and included in a one-step tamoxifen dose escalation study during 2 months. The escalated dose was calculated by multiplying the individual's endoxifen level at baseline relative to the average endoxifen concentration observed in CYP2D6 extensive metabolizers by 20 mg (120 mg maximum). Endoxifen levels and tamoxifen toxicity were determined at baseline and after 2 months, just before patients returned to the standard dose of 20 mg. Tamoxifen dose escalation in CYP2D6 poor and intermediate metabolizers significantly increased endoxifen concentrations (p < 0.001; p = 0.002, respectively) without increasing side effects. In intermediate metabolizers, dose escalation increased endoxifen to levels comparable with those observed in extensive metabolizers. In poor metabolizers, the mean endoxifen level increased from 24 to 81 % of the mean concentration in extensive metabolizers. In all patients, the endoxifen threshold of 5.97 ng/ml (=16.0 nM) reported by Madlensky et al. was reached following dose escalation. CYP2D6 genotype- and endoxifen-guided tamoxifen dose escalation increased endoxifen concentrations without increasing short-term side effects. Whether such tamoxifen dose escalation is effective and safe in view of long-term toxic effects is uncertain and needs to be explored. PMID:26369533

  3. Stimulation of skeletal muscle protein synthesis in neonatal pigs by long-term infusion of leucine is amino acid dependent

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infusing leucine for 1 hr increases skeletal muscle protein synthesis in neonatal pigs, but this is not sustained for 2 h unless the leucine-induced fall in amino acids is prevented. We aimed to determine whether continuous leucine infusion can stimulate protein synthesis for a prolonged period whe...

  4. Stimulation of muscle protein synthesis by prolonged parenteral infusion of leucine is dependent on amino acid availability in neonatal pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The postprandial rise in amino acids, particularly leucine, stimulates muscle protein synthesis in neonates. Previously, we showed that a 1-h infusion of leucine increased protein synthesis, but this response was not sustained for 2 h unless the leucine-induced decrease in amino acids was prevented....

  5. Effectiveness of an Increased Dose of Bovamine Compared to a Lower Dose to Reduce Salmonella in Fed Cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Category: Pre-harvest pathogen reduction Published: unpublished to date Objective: To examine the effect of increasing the probiotic dose from Bovamine® to Bovamine® Defend™ on the prevalence of Salmonella in pen environments, fecal samples and subiliac lymph nodes of fed cattle. Experimental ...

  6. Effects of leucine supplemented diet on intestinal absorption in tumor bearing pregnant rats

    PubMed Central

    Ventrucci, Gislaine; de Mello, Maria Alice Roston; Gomes-Marcondes, Maria Cristina Cintra

    2002-01-01

    Background It is known that amino acid oxidation is increased in tumor-bearing rat muscles and that leucine is an important ketogenic amino acid that provides energy to the skeletal muscle. Methods To evaluate the effects of a leucine supplemented diet on the intestinal absorption alterations produced by Walker 256, growing pregnant rats were distributed into six groups. Three pregnant groups received a normal protein diet (18% protein): pregnant (N), tumor-bearing (WN), pair-fed rats (Np). Three other pregnant groups were fed a diet supplemented with 3% leucine (15% protein plus 3% leucine): leucine (L), tumor-bearing (WL) and pair-fed with leucine (Lp). Non pregnant rats (C), which received a normal protein diet, were used as a control group. After 20 days, the animals were submitted to intestinal perfusion to measure leucine, methionine and glucose absorption. Results Tumor-bearing pregnant rats showed impairment in food intake, body weight gain and muscle protein content, which were less accentuated in WL than in WN rats. These metabolic changes led to reduction in both fetal and tumor development. Leucine absorption slightly increased in WN group. In spite of having a significant decrease in leucine and methionine absorption compared to L, the WL group has shown a higher absorption rate of methionine than WN group, probably due to the ingestion of the leucine supplemented diet inducing this amino acid uptake. Glucose absorption was reduced in both tumor-bearing groups. Conclusions Leucine supplementation during pregnancy in tumor-bearing rats promoted high leucine absorption, increasing the availability of the amino acid for neoplasic cells and, mainly, for fetus and host utilization. This may have contributed to the better preservation of body weight gain, food intake and muscle protein observed in the supplemented rats in relation to the non-supplemented ones. PMID:11955290

  7. Failure of dietary leucine to influence the tryptophan-niacin pathway in the chicken.

    PubMed

    Penz, A M; Clifford, A J; Rogers, Q R; Kratzer, F H

    1984-01-01

    Three experiments were conducted with young chicks to determine whether dietary leucine affects the conversion of tryptophan to niacin. Either tryptophan or niacin improved growth and reduced perosis when chicks were fed a purified diet marginal in tryptophan and deficient in niacin. Addition of 4.8% L-leucine to the diet did not alter the growth and perosis prevention response obtained with tryptophan. Liver weight was slightly increased by the addition of 5.4% L-leucine to the diet. Plasma insulin was slightly reduced by leucine and by isoleucine and valine. Picolinic carboxylase in the kidney was reduced in chicks fed 0.2% tryptophan with no niacin and was also reduced when isoleucine and valine were added to the diets. Liver picolinic carboxylase activity was not influenced by diet. Plasma isoleucine and valine were reduced by the addition of leucine to the diet and were increased again when isoleucine and valine were added to the diet. Plasma leucine was increased by the addition of leucine but was not altered by valine and isoleucine. Plasma tryptophan was not influenced by dietary supplements of leucine or isoleucine and valine. The results show that in the chick there is no evidence for an effect of leucine on the tryptophan to niacin pathway. PMID:6693983

  8. Increasing the Therapeutic Ratio of Stereotactic Ablative Radiotherapy by Individualized Isotoxic Dose Prescription.

    PubMed

    Zindler, Jaap D; Thomas, Charles R; Hahn, Stephen M; Hoffmann, Aswin L; Troost, Esther G C; Lambin, Philippe

    2016-02-01

    To obtain a favorable tradeoff between treatment benefits and morbidity ("therapeutic ratio"), radiotherapy (RT) dose is prescribed according to the tumor volume, with the goal of controlling the disease while respecting normal tissue tolerance levels. We propose a new paradigm for tumor dose prescription in stereotactic ablative radiotherapy (SABR) based on organ-at-risk (OAR) tolerance levels called isotoxic dose prescription (IDP), which is derived from experiences and limitations of conventionally fractionated radiotherapy. With IDP, the radiation dose is prescribed based on the predefined level of normal tissue complication probability of a nearby dose-limiting OAR at a prespecified dose-volume constraint. Simultaneously, the prescribed total tumor dose (TTD) is maximized to the technically highest achievable level in order to increase the local tumor control probability (TCP). IDP is especially relevant for tumors located at eloquent locations or for large tumors in which severe toxicity has been described. IDP will result in a lower RT dose or a treatment scheduled with more fractions if the OAR tolerance level is exceeded, and potential dose escalation occurs when the OAR tolerance level allows it and when it is expected to be beneficial (if TCP < 90%). For patients with small tumors at noneloquent sites, the current SABR dose prescription already results in high rates of local control at low toxicity rates. In this review, the concept of IDP is described in the context of SABR. PMID:26476075

  9. Triennial growth symposium: Leucine acts as a nutrient signal to stimulate protein synthesis in neonatal pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The postprandial increases in AA and insulin independently stimulate protein synthesis in skeletal muscle of piglets. Leucine is an important mediator of the response to AA. We have shown that the postprandial increase in leucine, but not isoleucine or valine, acutely stimulates muscle protein synth...

  10. Stimulation of muscle protein synthesis by leucine is dependent on plasma amino acid availability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have reported that a physiological increase in plasma leucine increased translation initiation factor activity during 60- and 120-min leucine infusion. Muscle protein synthesis was stimulated at 60 min but not at 120 min, perhaps due to the decrease (-50%) in plasma essential amino acids (AA). ...

  11. Increasing Use of Dose-Escalated External Beam Radiation Therapy for Men With Nonmetastatic Prostate Cancer

    SciTech Connect

    Swisher-McClure, Samuel; Mitra, Nandita; Woo, Kaitlin; Smaldone, Marc; Uzzo, Robert; Bekelman, Justin E.

    2014-05-01

    Purpose: To examine recent practice patterns, using a large national cancer registry, to understand the extent to which dose-escalated external beam radiation therapy (EBRT) has been incorporated into routine clinical practice for men with prostate cancer. Methods and Materials: We conducted a retrospective observational cohort study using the National Cancer Data Base, a nationwide oncology outcomes database in the United States. We identified 98,755 men diagnosed with nonmetastatic prostate cancer between 2006 and 2011 who received definitive EBRT and classified patients into National Comprehensive Cancer Network (NCCN) risk groups. We defined dose-escalated EBRT as total prescribed dose of ≥75.6 Gy. Using multivariable logistic regression, we examined the association of patient, clinical, and demographic characteristics with the use of dose-escalated EBRT. Results: Overall, 81.6% of men received dose-escalated EBRT during the study period. The use of dose-escalated EBRT did not vary substantially by NCCN risk group. Use of dose-escalated EBRT increased from 70.7% of patients receiving treatment in 2006 to 89.8% of patients receiving treatment in 2011. On multivariable analysis, year of diagnosis and use of intensity modulated radiation therapy were significantly associated with receipt of dose-escalated EBRT. Conclusions: Our study results indicate that dose-escalated EBRT has been widely adopted by radiation oncologists treating prostate cancer in the United States. The proportion of patients receiving dose-escalated EBRT increased nearly 20% between 2006 and 2011. We observed high utilization rates of dose-escalated EBRT within all disease risk groups. Adoption of intensity modulated radiation therapy was strongly associated with use of dose-escalated treatment.

  12. Exogenous valine reduces conversion of leucine to 3-methyl-1-butanol in Saccharomyces cerevisiae

    SciTech Connect

    Bigelis, R.; Weir, P.D.; Jones, R.R.M.; Umbarger, H.E.

    1983-02-01

    Mutant strains of the yeast Saccharomyces cerevisiae that require branched-chain amino acids must be supplemented with large concentrations (up to 10 mM) of these amino acids to satisfy their nutritional requirements. The utilization of one branched-chain amino acid, leucine, was examined in several leul strains of yeast grown aerobically in a glucose-ammonium salts minimal medium containing a limiting concentration (0.2 mM) of leucine. In this medium, the leucine requirement of the auxotrophic strains could be reduced by valine, another branched-chain amino acid. Increasing the valine concentration increased the cell yields of cultures and also reduced the levels of 3-methyl-1-butanol detected in the medium by gas chromatography. The concentration of 3-methyl-1-butanol was reduced from 122.0 to 48.9 ..mu..M when 5.0 mM valine was supplemented to limiting-leucine cultures. The amino acids isoleucine, threonine, norleucine, norvaline, ..cap alpha..-amino-butyrate, alanine, and glycine also spared the leucine requirement of leucine auxotrophs, most likely because they resemble leucine and competed for its uptake. We propose that leucine analogs restrict the entry and degradation of leucine and thus reduce its conversion to 3-methyl-1-butanol, a major component of fuel oil.

  13. Increase of onion yield through low dose of gamma irradiation of its seeds

    NASA Astrophysics Data System (ADS)

    Wiendl, F. M.; Wiendl, F. W.; Wiendl, J. A.; Vedovatto, A.; Arthur, V.

    1995-02-01

    The increase of onions' yield could be achieved by the common farmer through the use of nuclear techniques. This report describes the results obtained with the irradiation of onion seeds, with low doses of gamma radiations (Cobalt-60), at doses of 0 (control), 150, 400 and 700 Gy. Beyond the proper onion's variety also the use of low dose rates of 13.1, 39.2 and 52.3 Gy per hour were of the great importance during irradiation. The results showed to be promising, both in laboratory studies and in the field, resulting in an increase of onions production: A greater number of seedlings, bulbs and a higher yield in weight per hectar were planted. In the field the most promising dose and dose rate to the variety "Super-X" were respectively 150 Gy and 13.1 Gy per hour, yielding an 24.9 percent heavier weight of onions than the control. The other tested variety was "Granex-33", which did not respond so favorable to irradiation. However, also with this variety we harvested a 2.1 percent heavier weight than its control, if the onion seeds were irradiated with the dose of 700 Gy at a dose dose rate of 13.1 Gy per hour.

  14. Differential transport properties of D-leucine and L-leucine in the archaeon, Halobacterium salinarum.

    PubMed

    Tanaka, M; Mukohata, Y; Yuasa, S

    2000-04-01

    The transport of D-leucine was compared with that of L-leucine in Halobacterium salinarum. When a high-outside/low-inside Na+ gradient was imposed, D-leucine as well as L-leucine accumulated in envelope vesicles, supporting the hypothesis that D-leucine is transported via a symport system along with Na+. Kinetic analyses, including inhibition experiments, indicated that both enantiomers are transported via a common carrier. However, a Hill plot indicated a single binding site for Na+ during L-leucine transport, but dual binding sites for Na+ during D-leucine transport. Furthermore, D-leucine transport was dependent on electrical membrane potential, suggesting that a transporter bound with D-leucine is positively charged. L-leucine transport was slightly, if at all, dependent on membrane potential, suggesting that a transporter bound with L-leucine is electrically neutral. These results indicate that the leucine carrier in Halobacterium salinarum translocates two moles of Na+ per mole of D-leucine, and one mole of Na+ per mole of L-leucine. PMID:10779875

  15. Is Increased Low-dose somatic Radiosensitivity Associated with Increased Transgenerational Germline Mutation

    SciTech Connect

    Brenner, David J.

    2008-10-02

    Using single-molecule polymerase chain reaction, the frequency of spontaneous and radiation-induced mutation at an expanded simple tandem repeat (ESTR) locus was studied in DNA samples extracted from sperm and bone marrow of Atm knockout (Atm+/–) heterozygous male mice. The frequency of spontaneous mutation in sperm and bone marrow in Atm+/– males did not significantly differ from that in wild-type BALB/c mice. Acute gamma-ray exposure did not affect ESTR mutation frequency in bone marrow and resulted in similar increases in sperm samples taken from Atm+/– and BALB/c males. Taken together, these results suggest that the Atm haploinsufficiency analyzed in our study does not affect spontaneous and radiation-induced ESTR mutation frequency in mice.

  16. Effect of Increasing Radiation Doses on Local and Distant Failures in Patients With Localized Prostate Cancer

    SciTech Connect

    Kupelian, Patrick A. Ciezki, Jay; Reddy, Chandana A.; Klein, Eric A.; Mahadevan, Arul

    2008-05-01

    Purpose: To study the effect of radiation dose on local failure (LF) and distant metastasis (DM) in prostate cancer patients treated with external beam radiotherapy. Methods and Materials: The study sample consisted of 919 Stage T1-T3N0M0 patients treated with radiotherapy alone. Three separate dose groups were analyzed: <72 Gy (n = 552, median dose, 68.4 Gy), {>=}72 but <82 Gy (n = 215, median dose, 78 Gy), and {>=}82 Gy (n = 152, median dose, 83 Gy). The median follow-up period for all patients and those receiving <72 Gy, {>=}72 but <82 Gy, and {>=}82 Gy was 97, 112, 94, and 65 months, respectively. Results: For all patients, the LF rate at 10 and 15 years was 6% and 13%, respectively. The 7-year LF rate stratified by dose group (<72 Gy, {>=}72 but <82 Gy, and {>=}82 Gy) was 6%, 2%, and 2%, respectively (p 0.012). For all patients, the DM rate at 10 and 15 years was 10% and 17%, respectively. The 7-year DM rate stratified by dose group (<72 Gy, {>=}72 but <82 Gy, and {>=}82 Gy) was 9%, 6%, and 1%, respectively (p = 0.008). Multivariate analysis revealed T stage (p < 0.001), pretreatment prostate-specific antigen level (p = 0.001), Gleason score (p < 0.001), and dose (p = 0.018) to be independent predictors of DM. For all 919 patients, multivariate analysis revealed only Gleason score (p = 0.009) and dose (p 0.004) to be independent predictors of LF. Conclusion: Although the effect of increasing radiation doses has been documented mostly for biochemical failure rates, the results of our study have shown a clear association between greater radiation doses and lower LF and DM rates.

  17. Long-term leucine induced stimulation of muscle protein synthesis is amino acid dependent

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infusing leucine for 1 h increases skeletal muscle protein synthesis in the neonate, but this is not sustained for 2 h unless the corresponding fall in amino acids is prevented. This study aimed to determine whether a continuous leucine infusion can stimulate protein synthesis for a prolonged period...

  18. Dietary leucine requirement of juvenile Japanese seabass ( Lateolabrax japonicus)

    NASA Astrophysics Data System (ADS)

    Li, Yan; Cheng, Zhenyan; Mai, Kangsen; Ai, Qinghui

    2015-02-01

    A 56-day feeding trial was conducted to examine the dietary leucine requirement of juvenile Japanese seabass in seawater floating net cages (1.5 m × 1.5 m × 2.0 m). Six isonitrogenous (crude protein 40%) and isoenergetic (gross energy 20 kJ g-1) diets were formulated to contain different concentrations of leucine (0.9%, 1.49%, 2.07%, 2.70%, 3.30% and 3.88% of dry matter). Crystalline L-amino acids were supplemented to simulate the whole body amino acid pattern of Japanese seabass except for leucine. Three groups (30 fish individuals each, 8.0 g ± 0.20 g in initial weight) were fed to apparent satiation at 5:00 and 17:30 every day. During the experimental period, the water temperature ranged from 26 to 32δC and salinity from 26 to 30, and the dissolved oxygen was maintained at 7 mg L-1. The results showed that weight gain ( WG), nitrogen retention ( NR), feed efficiency ( FE) and protein efficiency ratio ( PER) were significantly increased when dietary leucine was increased from 0.90% to 2.70% of dry matter, and then declined. WG was the highest when fish were fed D4 containing 2.70% of leucine. No significant differences were observed in body composition among dietary treatments ( P > 0.05). Considering the change of WG, the optimum dietary leucine requirement of juvenile Japanese seabass was either 2.39% of dry matter or 5.68% of dietary protein.

  19. A method to evaluate the dose increase in CT with iodinated contrast medium

    SciTech Connect

    Amato, Ernesto; Lizio, Domenico; Settineri, Nicola; Di Pasquale, Andrea; Salamone, Ignazio; Pandolfo, Ignazio

    2010-08-15

    Purpose: The objective of this study is to develop a method to calculate the relative dose increase when a computerized tomography scan (CT) is carried out after administration of iodinated contrast medium, with respect to the same CT scan in absence of contrast medium. Methods: A Monte Carlo simulation in GEANT4 of anthropomorphic neck and abdomen phantoms exposed to a simplified model of CT scanner was set up in order to calculate the increase of dose to thyroid, liver, spleen, kidneys, and pancreas as a function of the quantity of iodine accumulated; a series of experimental measurements of Hounsfield unit (HU) increment for known concentrations of iodinated contrast medium was carried out on a Siemens Sensation 16 CT scanner in order to obtain a relationship between the increment in HU and the relative dose increase in the organs studied. The authors applied such a method to calculate the average dose increase in three patients who underwent standard CT protocols consisting of one native scan in absence of contrast, followed by a contrast-enhanced scan in venous phase. Results: The authors validated their GEANT4 Monte Carlo simulation by comparing the resulting dose increases for iodine solutions in water with the ones presented in literature and with their experimental data obtained through a Roentgen therapy unit. The relative dose increases as a function of the iodine mass fraction accumulated and as a function of the Hounsfield unit increment between the contrast-enhanced scan and the native scan are presented. The data shown for the three patients exhibit an average relative dose increase between 22% for liver and 74% for kidneys; also, spleen (34%), pancreas (28%), and thyroid (48%) show a remarkable average increase. Conclusions: The method developed allows a simple evaluation of the dose increase when iodinated contrast medium is used in CT scans, basing on the increment in Hounsfield units observed on the patients' organs. Since many clinical protocols

  20. Protein-leucine ingestion activates a regenerative inflammo-myogenic transcriptome in skeletal muscle following intense endurance exercise.

    PubMed

    Rowlands, David S; Nelson, Andre R; Raymond, Frederic; Metairon, Sylviane; Mansourian, Robert; Clarke, Jim; Stellingwerff, Trent; Phillips, Stuart M

    2016-01-01

    Protein-leucine supplement ingestion following strenuous endurance exercise accentuates skeletal-muscle protein synthesis and adaptive molecular responses, but the underlying transcriptome is uncharacterized. In a randomized single-blind triple-crossover design, 12 trained men completed 100 min of high-intensity cycling then ingested 70/15/180/30 g protein-leucine-carbohydrate-fat (15LEU), 23/5/180/30 g (5LEU), or 0/0/274/30 g (CON) beverages during the first 90 min of a 240 min recovery period. Vastus lateralis muscle samples (30 and 240 min postexercise) underwent transcriptome analysis by microarray followed by bioinformatic analysis. Gene expression was regulated by protein-leucine in a dose-dependent manner affecting the inflammatory response and muscle growth and development. At 30 min, 15LEU and 5LEU vs. CON activated transcriptome networks with gene-set functions involving cell-cycle arrest (Z-score 2.0-2.7, P < 0.01), leukocyte maturation (1.7, P = 0.007), cell viability (2.4, P = 0.005), promyogenic networks encompassing myocyte differentiation and myogenin (MYOD1, MYOG), and a proteinaceous extracellular matrix, adhesion, and development program correlated with plasma lysine, arginine, tyrosine, taurine, glutamic acid, and asparagine concentrations. High protein-leucine dose (15LEU-5LEU) activated an IL-1I-centered proinflammatory network and leukocyte migration, differentiation, and survival functions (2.0-2.6, <0.001). By 240 min, the protein-leucine transcriptome was anti-inflammatory and promyogenic (IL-6, NF- β, SMAD, STAT3 network inhibition), with overrepresented functions including decreased leukocyte migration and connective tissue development (-1.8-2.4, P < 0.01), increased apoptosis of myeloid and muscle cells (2.2-3.0, P < 0.002), and cell metabolism (2.0-2.4, P < 0.01). The analysis suggests protein-leucine ingestion modulates inflammatory-myogenic regenerative processes during skeletal muscle recovery from endurance exercise. Further

  1. Regulation of Leucine Biosynthesis in Bacillus subtilis

    PubMed Central

    Ward, Jonathan B.; Zahler, Stanley A.

    1973-01-01

    The biosynthesis of α-isopropylmalate (αIPM) synthetase, IPM isomerase, and βIPM dehydrogenase in Bacillus subtilis can be derepressed in leucine auxotrophs by limiting them for leucine. The derepression of the three enzymes is apparently coordinate. A class of mutants resistant to 4-azaleucine excretes leucine and has derepressed levels of all three enzymes. The azaleucine-resistance mutations may lie in a gene (azlA) encoding a repressor. Efforts to find mutations characteristic of a constitutive operator have been unsuccessful. No polar mutations have been found among nine leucine auxotrophs that have characteristics of frameshift mutations. The enzyme catalyzing the first step in leucine biosynthesis, αIPM synthetase, is sensitive to feedback inhibition by leucine. We conclude that leucine biosynthesis is controlled by the inhibition of the activity of the first biosynthetic enzyme by leucine, and by the repression of the synthesis of the first three biosynthetic enzymes by leucine. The repression of the three enzymes may be under the control of a single repressor and a single operator, or of a single repressor and a separate operator for each structural gene. PMID:4200854

  2. Leucine metabolism in cirrhotic patients with hepatic encephalopathy

    SciTech Connect

    McGhee, A.S.

    1985-01-01

    The purpose of this study was to determine whether increased oxidation of or protein synthesis requiring leucine occurs in cirrhotic patients. Five control subjects and four subjects with cirrhosis were equilibrated on a baseline diet (0.6 g protein per kg ideal body weight (IBW)) with sufficient nonprotein calories to preclude negative nitrogen balance. An additional four patients were equilibrated on the same type of diet with a higher protein level (0.75 g per kg IBW). Control subjects and the patients were then studied during continuous infusion of L-(/sup 15/N, 1-/sup 13/C) leucine in the fasted state and, in the fed state, with a Propac diet which had the same distribution of energy nutrients as the baseline diets. Plasma levels of L-(/sup 15/N, 1-/sup 13/C), L-(1-/sup 13/C) and L-(/sup 15/N) leucine were measured during isotopic steady state by gas chromatography-mass spectrometry and fractional excretion of /sup 13/CO/sup 2/ in breath samples were analyzed by isotopic ratio mass spectrometry. During the fasted and fed states leucine metabolism was measured to quantitate rates of nitrogen flux (Q/sub N/), carbon flux (Q/sub c/) and oxidation to carbon dioxide and water (C). From these measured values, proteins breakdown (B), protein synthesis (S), deamination (X/sup 0/) and reamination (X/sub N/) were calculated. The results showed that protein synthesis and leucine metabolism were identical in controls and patients when both were fed a diet with 0.6 g protein/kg IBW and maintenance level of nonprotein calories. The data also showed that leucine metabolism can be quantitatively and reproducibly measured in subjects with cirrhosis.

  3. Leucine supplementation via drinking water reduces atherosclerotic lesions in apoE null mice

    PubMed Central

    Zhao, Yang; Dai, Xiao-yan; Zhou, Zhou; Zhao, Ge-xin; Wang, Xian; Xu, Ming-jiang

    2016-01-01

    Aim: Recent evidence suggests that the essential amino acid leucine may be involved in systemic cholesterol metabolism. In this study, we investigated the effects of leucine supplementation on the development of atherosclerosis in apoE null mice. Methods: ApoE null mice were fed with chow supplemented with leucine (1.5% w/v) in drinking water for 8 week. Aortic atherosclerotic lesions were examined using Oil Red O staining. Plasma lipoprotein-cholesterol levels were measured with fast protein liquid chromatography. Hepatic gene expression was detected using real-time PCR and Western blot analyses. Results: Leucine supplementation resulted in 57.6% reduction of aortic atherosclerotic lesion area in apoE null mice, accompanied by 41.2% decrease of serum LDL-C levels and 40.2% increase of serum HDL-C levels. The body weight, food intake and blood glucose level were not affected by leucine supplementation. Furthermore, leucine supplementation increased the expression of Abcg5 and Abcg8 (that were involved in hepatic cholesterol efflux) by 1.28- and 0.86-fold, respectively, and significantly increased their protein levels. Leucine supplementation also increased the expression of Srebf1, Scd1 and Pgc1b (that were involved in hepatic triglyceride metabolism) by 3.73-, 1.35- and 1.71-fold, respectively. Consequently, leucine supplementation resulted in 51.77% reduction of liver cholesterol content and 2.2-fold increase of liver triglyceride content. Additionally, leucine supplementation did not affect the serum levels of IL-6, IFN-γ, TNF-α, IL-10 and IL-12, but markedly decreased the serum level of MCP-1. Conclusion: Leucine supplementation effectively attenuates atherosclerosis in apoE null mice by improving the plasma lipid profile and reducing systemic inflammation. PMID:26687933

  4. Low-dose oral cadmium increases airway reactivity and lung neuronal gene expression in mice.

    PubMed

    Chandler, Joshua D; Wongtrakool, Cherry; Banton, Sophia A; Li, Shuzhao; Orr, Michael L; Barr, Dana Boyd; Neujahr, David C; Sutliff, Roy L; Go, Young-Mi; Jones, Dean P

    2016-07-01

    Inhalation of cadmium (Cd) is associated with lung diseases, but less is known concerning pulmonary effects of Cd found in the diet. Cd has a decades-long half-life in humans and significant bioaccumulation occurs with chronic dietary intake. We exposed mice to low-dose CdCl2 (10 mg/L in drinking water) for 20 weeks, which increased lung Cd to a level similar to that of nonoccupationally exposed adult humans. Cd-treated mice had increased airway hyperresponsiveness to methacholine challenge, and gene expression array showed that Cd altered the abundance of 443 mRNA transcripts in mouse lung. In contrast to higher doses, low-dose Cd did not elicit increased metallothionein transcripts in lung. To identify pathways most affected by Cd, gene set enrichment of transcripts was analyzed. Results showed that major inducible targets of low-dose Cd were neuronal receptors represented by enriched olfactory, glutamatergic, cholinergic, and serotonergic gene sets. Olfactory receptors regulate chemosensory function and airway hypersensitivity, and these gene sets were the most enriched. Targeted metabolomics analysis showed that Cd treatment also increased metabolites in pathways of glutamatergic (glutamate), serotonergic (tryptophan), cholinergic (choline), and catecholaminergic (tyrosine) receptors in the lung tissue. Protein abundance measurements showed that the glutamate receptor GRIN2A was increased in mouse lung tissue. Together, these results show that in mice, oral low-dose Cd increased lung Cd to levels comparable to humans, increased airway hyperresponsiveness and disrupted neuronal pathways regulating bronchial tone. Therefore, dietary Cd may promote or worsen airway hyperresponsiveness in multiple lung diseases including asthma. PMID:27401458

  5. Metabolic Effects of Increasing Doses of Nitisinone in the Treatment of Alkaptonuria.

    PubMed

    Gertsman, Ilya; Barshop, Bruce A; Panyard-Davis, Jan; Gangoiti, Jon A; Nyhan, William L

    2015-01-01

    Alkaptonuria is an autosomal recessive disease involving a deficiency of the enzyme homogentisate dioxygenase, which is involved in the tyrosine degradation pathway. The enzymatic deficiency results in high concentrations of homogentisic acid (HGA), which results in orthopedic and cardiac complications, among other symptoms. Nitisinone (NTBC) has been shown to effectively treat alkaptonuria by blocking the conversion of 4-hydroxyphenylpyruvate to HGA, but there have been concerns that using doses higher than about 2 mg/day could cause excessively high levels of tyrosine, resulting in crystal deposition and corneal pathology. We have enrolled seven patients in a study to determine whether higher doses of NTBC were effective at further reducing HGA levels while maintaining tyrosine at acceptable levels. Patients were given varying doses of NTBC (ranging from 2 to 8 mg/day) over the course of between 0.5 and 3.5 years. Urine HGA, plasma tyrosine levels, and plasma NTBC were then measured longitudinally at various doses. We found that tyrosine concentrations plateaued and did not reach significantly higher levels as NTBC doses were increased above 2 mg/day, while a significant drop in HGA continued from 2 to 4 mg/day, with no significant changes at higher doses. We also demonstrated using untargeted metabolomics that elevations in tyrosine from treatment resulted in proportional elevations in alternative tyrosine metabolic products, that of N-acetyltyrosine and γ-glutamyltyrosine. PMID:25665838

  6. Value of increasing film processing time to reduce radiation dose during mammography

    SciTech Connect

    Skubic, S.E.; Yagan, R.; Oravec, D.; Shah, Z. )

    1990-12-01

    We systematically tested the effects on radiation dose and image quality of increasing the mammographic film processing time from the standard 90 sec to 3 min. Hurter and Driffield curves were obtained for a Kodak Min-R-OM1-SO177 screen-film combination processed with Kodak chemistry. Image contrast and radiation dose were measured for two tissue-equivalent breast phantoms. We also compared sequential pairs of mammograms, one processed at 90 sec and one at 3 min, from 44 patients on the basis of nine categories of image quality. Increased processing time reduced breast radiation dose by 30%, increased contrast by 11%, and produced slight overall gains in image quality. Simple modifications can convert a 90-sec processor to a 3-min unit. We recommend that implementation of extended processing be considered, especially by those centers that obtain a large number of screening mammograms. Three-minute film processing can reduce breast radiation dose by 30% and increase contrast by 11% without compromising image quality.

  7. A Heterospecific Leucine Zipper Tetramer

    SciTech Connect

    Deng, Y.; Liu, J; Zheng, Q; Li, Q; Kallenbach, N; Lu, M

    2008-01-01

    Protein-protein interactions dictate the assembly of the macromolecular complexes essential for functional networks and cellular behavior. Elucidating principles of molecular recognition governing important interfaces such as coiled coils is a challenging goal for structural and systems biology. We report here that two valine-containing mutants of the GCN4 leucine zipper that fold individually as four-stranded coiled coils associate preferentially in mixtures to form an antiparallel, heterotetrameric structure. X-ray crystallographic analysis reveals that the coinciding hydrophobic interfaces of the hetero- and homotetramers differ in detail, explaining their partnering and structural specificity. Equilibrium disulfide exchange and thermal denaturation experiments show that the 50-fold preference for heterospecificity results from a combination of preferential packing and hydrophobicity. The extent of preference is sensitive to the side chains comprising the interface. Thus, heterotypic versus homotypic interaction specificity in coiled coils reflects a delicate balance in complementarity of shape and chemistry of the participating side chains.

  8. Do Increased Doses to Stem-Cell Niches during Radiation Therapy Improve Glioblastoma Survival?

    PubMed Central

    Adeberg, Sebastian; Harrabi, Semi Ben; Mohr, Angela; Rieber, Juliane; Rieken, Stefan; Debus, Juergen

    2016-01-01

    Background and Purpose. The reasons for the inevitable glioblastoma recurrence are yet understood. However, recent data suggest that tumor cancer stem cells (CSCs) in the stem-cell niches, with self-renewing capacities, might be responsible for tumor initiation, propagation, and recurrence. We aimed to analyze the effect of higher radiation doses to the stem-cell niches on progression-free survival (PFS) and overall survival (OS) in glioblastoma patients. Materials and Methods. Sixty-five patients with primary glioblastoma treated with radiation therapy were included in this retrospective analysis. The SVZ and DG were segmented on treatment planning magnetic resonance imaging, and the dose distributions to the structures were calculated. The relationship of dosimetry data and survival was evaluated using the Cox regression analysis. Results. Conventionally fractionated patients (n = 54) who received higher doses (Dmean ≥ 40 Gy) to the IL SVZ showed improved PFS (8.5 versus 5.2 months; p = 0.013). Furthermore, higher doses (Dmean ≥ 30 Gy) to the CL SVZ were associated with increased PFS (10.1 versus 6.9 months; p = 0.025). Conclusion. Moderate higher IL SVZ doses (≥40 Gy) and CL SVZ doses (≥30 Gy) are associated with improved PFS. Higher doses to the DG, the second stem-cell niche, did not influence the survival. Targeting the potential cancer stem cells in the SVZ might be a promising treatment approach for glioblastoma and should be addressed in a prospective randomized trial. PMID:27429623

  9. Increased Skin Dose With the Use of a Custom Mattress for Prone Breast Radiotherapy

    SciTech Connect

    Becker, Stewart J. Patel, Rakesh R.; Mackie, Thomas R.

    2007-10-01

    The purpose of this study was to measure and compare the loss of buildup to the skin of the breast in the prone position due to 2 different positioning systems during tangential external beam irradiation. Two experiments were performed; one with a standard nylon-covered foam support and another with a novel helium-filled Mylar bag support. The choice of helium-filled Mylar was to reduce the contamination to as low as possible. The experiments were designed to allow a surface dose measurement and a depth dose profile with the pads placed in the path of the beam in front of the detector. All measurements were taken using a Capintec PS-033 thin-window parallel plate ionization chamber. The standard nylon-covered foam pad caused the surface dose to rise as it got closer to the skin. When the pad was directly touching the surface, the surface dose increased by 300% compared to the result when no pad was present. This loss of buildup to the surface was similar to that of a custom bolus material. The opposite effect occurred with the use of the helium-filled Mylar bag, namely the surface dose gradually decreased as the pad got closer to the phantom. When the Mylar pad was directly touching the phantom, the surface dose was decreased by 7% compared to when no pad was present. The use of a foam pad could potentially result in a significant higher dose to the skin, resulting in an enhanced acute skin reaction. Therefore, special care should be taken in this clinical scenario and further investigation of an air- or helium-based mylar support pad should be investigated in the context of definitive breast radiation treatment.

  10. Phosphorylation of 4EBP by oral leucine administration was suppressed in the skeletal muscle of PGC-1α knockout mice.

    PubMed

    Yoshimura, Ryoji; Minami, Kimiko; Matsuda, Junichiro; Sawada, Naoki; Miura, Shinji; Kamei, Yasutomi

    2016-01-01

    Leucine is known to increase mTOR-mediated phosphorylation of 4EBP. In this study, leucine was administered to skeletal muscle-PGC-1α knockout mice. We observed attenuated 4EBP phosphorylation in the skeletal muscle, but not in the liver, of the PGC-1α knockout mice. These data suggest that skeletal muscle-PGC-1α is important for leucine-mediated mTOR activation and protein biosynthesis. PMID:26745679

  11. Leucine supplementation accelerates connective tissue repair of injured tibialis anterior muscle.

    PubMed

    Pereira, Marcelo G; Silva, Meiricris T; Carlassara, Eduardo O C; Gonçalves, Dawit A; Abrahamsohn, Paulo A; Kettelhut, Isis C; Moriscot, Anselmo S; Aoki, Marcelo S; Miyabara, Elen H

    2014-10-01

    This study investigated the effect of leucine supplementation on the skeletal muscle regenerative process, focusing on the remodeling of connective tissue of the fast twitch muscle tibialis anterior (TA). Young male Wistar rats were supplemented with leucine (1.35 g/kg per day); then, TA muscles from the left hind limb were cryolesioned and examined after 10 days. Although leucine supplementation induced increased protein synthesis, it was not sufficient to promote an increase in the cross-sectional area (CSA) of regenerating myofibers (p > 0.05) from TA muscles. However, leucine supplementation reduced the amount of collagen and the activation of phosphorylated transforming growth factor-β receptor type I (TβR-I) and Smad2/3 in regenerating muscles (p < 0.05). Leucine also reduced neonatal myosin heavy chain (MyHC-n) (p < 0.05), increased adult MyHC-II expression (p < 0.05) and prevented the decrease in maximum tetanic strength in regenerating TA muscles (p < 0.05). Our results suggest that leucine supplementation accelerates connective tissue repair and consequent function of regenerating TA through the attenuation of TβR-I and Smad2/3 activation. Therefore, future studies are warranted to investigate leucine supplementation as a nutritional strategy to prevent or attenuate muscle fibrosis in patients with several muscle diseases. PMID:25268835

  12. Leucine Supplementation Accelerates Connective Tissue Repair of Injured Tibialis Anterior Muscle

    PubMed Central

    Pereira, Marcelo G.; Silva, Meiricris T.; Carlassara, Eduardo O. C.; Gonçalves, Dawit A.; Abrahamsohn, Paulo A.; Kettelhut, Isis C.; Moriscot, Anselmo S.; Aoki, Marcelo S.; Miyabara, Elen H.

    2014-01-01

    This study investigated the effect of leucine supplementation on the skeletal muscle regenerative process, focusing on the remodeling of connective tissue of the fast twitch muscle tibialis anterior (TA). Young male Wistar rats were supplemented with leucine (1.35 g/kg per day); then, TA muscles from the left hind limb were cryolesioned and examined after 10 days. Although leucine supplementation induced increased protein synthesis, it was not sufficient to promote an increase in the cross-sectional area (CSA) of regenerating myofibers (p > 0.05) from TA muscles. However, leucine supplementation reduced the amount of collagen and the activation of phosphorylated transforming growth factor-β receptor type I (TβR-I) and Smad2/3 in regenerating muscles (p < 0.05). Leucine also reduced neonatal myosin heavy chain (MyHC-n) (p < 0.05), increased adult MyHC-II expression (p < 0.05) and prevented the decrease in maximum tetanic strength in regenerating TA muscles (p < 0.05). Our results suggest that leucine supplementation accelerates connective tissue repair and consequent function of regenerating TA through the attenuation of TβR-I and Smad2/3 activation. Therefore, future studies are warranted to investigate leucine supplementation as a nutritional strategy to prevent or attenuate muscle fibrosis in patients with several muscle diseases. PMID:25268835

  13. Slowing the increase in the population dose resulting from CT scans.

    PubMed

    Brenner, D J

    2010-12-01

    The annual number of CT scans in the U.S. is now over 70 million. The concern is that organ doses from CT are typically far larger than those from conventional X-ray examinations, and there is epidemiological evidence of a small but significant increased cancer risk at typical CT doses. Because CT is a superb diagnostic tool and because individual CT risks are small, when a CT scan is clinically indicated, the CT benefit/risk balance is by far in the patient's favor. Nevertheless, CT should operate under the ALARA (As Low As Reasonably Achievable) principle, and opportunities exist to reduce the significant population dose associated with CT without compromising patient care. The first opportunity is to reduce the dose per scan, and improved technology has much potential here. The second opportunity is selective replacement of CT with other modalities, such as for many head and spinal examinations (with MRI), and for diagnosing appendicitis (selective use of ultrasound + CT). Finally, a fraction of CT scans could be avoided entirely, as indicated by CT decision rules: Clinical decision rules for CT use represent a powerful approach for slowing down the increase in CT use, because they have the potential to overcome some of the major factors that result in some CT scans being undertaken when they are potentially not clinically helpful. In the U.S. and potentially elsewhere, legislative approaches are a possible option, to improve quality control and reduce clinically unneeded CT use, and it is also possible that upcoming changes in heath care economics will tend to slow the increase in such CT use. PMID:20731591

  14. Determination of the safety of leucine supplementation in healthy elderly men.

    PubMed

    Rasmussen, Betina; Gilbert, Erin; Turki, Abrar; Madden, Kenneth; Elango, Rajavel

    2016-07-01

    Leucine, a branched-chain amino acid (BCAA), has been shown to stimulate muscle protein synthesis, and thus has been proposed to prevent age-related muscle atrophy (sarcopenia). Therefore, leucine supplementation may have potential benefits in elderly populations to preserve muscle mass. The tolerable upper intake level (UL) for leucine intake in young men has recently been determined to be 500 mg kg(-1) day(-1), and increases in blood ammonia concentrations were seen at intake levels above 500 mg kg(-1) day(-1); the UL for leucine in elderly is unknown. The objective of the current study was to determine the safety of leucine supplementation in healthy elderly men. Six healthy elderly men (72.2 ± 3.5 years) received graded stepwise increases in leucine intakes ranging from 50 to 750 mg kg(-1) day(-1), on eight separate study days. Plasma and urinary biochemical variables, including blood ammonia, and an oral primed-continuous protocol of L-1-(13)C-Leucine was performed. Blood ammonia concentrations above normal values (35 µmol/L) were observed at leucine intakes >550 mg kg(-1) day(-1). Leucine oxidation measured as a F(13)CO2 (rate of label tracer oxidation) increased with increasing leucine intakes and started to plateau after 450 mg kg(-1) day(-1). Two-phased linear regression analysis of the F(13)CO2 data revealed a breakpoint of 431 mg kg(-1) day(-1) (R (2) = 0.73), suggesting that the upper limit to oxidize leucine was reached at that point. Taking the data together the upper limit for leucine intake in healthy elderly could be set similar to young men at 500 mg kg(-1) day(-1) or ~35 g/day for an individual weighing 70 kg. PMID:27138628

  15. Transactivation and transformation by Myb are negatively regulated by a leucine-zipper structure.

    PubMed Central

    Kanei-Ishii, C; MacMillan, E M; Nomura, T; Sarai, A; Ramsay, R G; Aimoto, S; Ishii, S; Gonda, T J

    1992-01-01

    The negative regulatory domain of the c-myb protooncogene product (c-Myb) normally represses transcriptional activation by c-Myb. We show here that a leucine-zipper structure is a component of the negative regulatory domain, because its disruption markedly increases both the transactivating and transforming capacities of c-Myb. We also demonstrate that this leucine-zipper structure can interact with cellular proteins. Our results suggest that an inhibitor that suppresses transactivation binds to c-Myb through the leucine zipper and that c-Myb can be oncogenically activated by missense mutation. Images PMID:1557416

  16. Impact of body weight and missed doses on lopinavir concentrations with standard and increased lopinavir/ritonavir doses during late pregnancy

    PubMed Central

    Cressey, Tim R.; Urien, Saik; Capparelli, Edmund V.; Best, Brookie M.; Buranabanjasatean, Sudanee; Limtrakul, Aram; Rawangban, Boonsong; Sabsanong, Prapan; Treluyer, Jean-Marc; Jourdain, Gonzague; Stek, Alice; Lallemant, Marc; Mirochnick, Mark

    2015-01-01

    Objectives To assess the influence of body weight and missed doses on lopinavir pharmacokinetics with standard and increased doses of lopinavir/ritonavir melt extrusion tablets during late pregnancy. Patients and methods Lopinavir concentration data during the third trimester of pregnancy were pooled from clinical trials in Thailand (NCT00409591) and the USA (NCT00042289). A total of 154 HIV-infected pregnant women receiving either 400/100 mg (standard) or 600/150 mg (increased) twice daily had lopinavir plasma concentration data available. Population parameters were estimated using non-linear mixed-effects regression models. Monte Carlo simulations were performed to estimate the probability of achieving target lopinavir trough concentrations (>1.0 mg/L) with standard and increased doses of lopinavir/ritonavir during pregnancy. Results The median (range) age, weight and gestational age were 28 years (18–43), 62 kg (45–123) and 33 weeks (29–38), respectively. Body weight influenced lopinavir oral clearance (CL/F) and volume of distribution (V/F). Population estimates of lopinavir CL/F and V/F were 6.21 L/h/70 kg and 52.6 L/70 kg, respectively. Based on simulations, the highest risk of subtherapeutic trough concentrations was for women weighing >100 kg using the standard dose (∼7%), while the risk was <2% with the 600/150 mg dose for women weighing 40–130 kg. After a missed dose, 61% of women have lopinavir concentrations below target prior to the next dose with the standard dose compared with 42% with the increased dose. Conclusions Standard dosing provides adequate lopinavir trough concentrations for the majority of pregnant women but increased doses may be preferable for women weighing >100 kg and with a history of lopinavir/ritonavir use and/or adherence issues. PMID:25261418

  17. Structure and dissolution of L-leucine-coated salbutamol sulphate aerosol particles.

    PubMed

    Raula, Janne; Seppälä, Jukka; Malm, Jari; Karppinen, Maarit; Kauppinen, Esko I

    2012-06-01

    L-Leucine formed different crystalline coatings on salbutamol sulphate aerosol particles depending on the saturation conditions of L-leucine. The work emphasizes a careful characterization of powders where structural compartments such as crystal size and particle coating may affect the performance of drug when administered. The sublimation of L-leucine from the aerosol particles took place 90°C lower temperature than the bulk L-leucine which was attributed to result from the sublimation of L-leucine from nano-sized crystalline domains. The dissolution slowed down and initial dissolution rate decreased with increasing L-leucine content. Decreasing crystalline domains to nano-scale improve heat and mass transfer which was observed as the lowered decomposition temperature of the drug salbutamol sulphate and the sublimation temperature of surface material L-leucine as well as the altered dissolution characteristics of the drug. The structure of the coated drug particles was studied by means of thermal analysis techniques (DSC and TG), and the dissolution of salbutamol sulphate was studied as an on-line measurement in a diffusion cell. PMID:22562614

  18. Purification and identification of a novel leucine aminopeptidase from Bacillus thuringiensis israelensis.

    PubMed

    Cahan, Rivka; Hetzroni, Efrat; Nisnevitch, Marina; Nitzan, Yeshayahu

    2007-11-01

    A novel leucine aminopeptidase was purified from a Bacillus thuringiensis israelensis (Bti) culture. The purification stages included heating the concentrated supernatant to 65 degrees C for 90 min, anion-exchange chromatography by DEAE cellulose, and hydrophobic chromatography by phenyl Sepharose. The specific activity of leucine aminopeptidase after the hydrophobic chromatography increased by 215.5-fold and the yield was 16%. The molecular weight of the active enzyme was 59 kDa. Mass spectrometry analysis of the 59-kDa leucine aminopeptidase revealed that this protein has at least 41% homology with the cytosol leucine aminopeptidase produced by Bacillus cereus. Maximal leucine aminopeptidase activity occurred at 65 degrees C, pH 10 toward leucine as the amino acid terminus. The enzyme was strongly inhibited by bestatin, dithiothreitol, and 1,10-phenanthroline, indicating that the enzyme might be considered as a metallo-aminopeptidase that has disulfide bonds at the catalytic site or at a region that influences its configuration. Examination of the purified leucine aminopeptidase's effect on the activation of the protoxin Cyt1Aa from Bti revealed that when it acts synergistically with Bti endogenous proteases, it has only a minor role in the processing of Cyt1Aa into an active toxin. PMID:17682820

  19. Leucine induced dephosphorylation of Sestrin2 promotes mTORC1 activation.

    PubMed

    Kimball, Scot R; Gordon, Bradley S; Moyer, Jenna E; Dennis, Michael D; Jefferson, Leonard S

    2016-08-01

    The studies described herein were designed to explore the role of Sestrin2 in mediating the selective action of leucine to activate mTORC1. The results demonstrate that Sestrin2 is a phosphoprotein and that its phosphorylation state is responsive to the availability of leucine, but not other essential amino acids. Moreover, leucine availability-induced alterations in Sestrin2 phosphorylation correlated temporally and dose dependently with the activation state of mTORC1, there being a reciprocal relationship between the degree of phosphorylation of Sestrin2 and the extent of repression of mTORC1. With leucine deprivation, Sestrin2 became more highly phosphorylated and interacted more strongly with proteins of the GATOR2 complex. Notably, in cells lacking the protein kinase ULK1, the activation state of mTORC1 was elevated in leucine-deficient medium, such that the effect of re-addition of the amino acid was blunted. In contrast, overexpression of ULK1 led to hyperphosphorylation of Sestrin2 and enhanced its interaction with GATOR2. Neither rapamycin nor Torin2 had any effect on Sestrin2 phosphorylation, suggesting that leucine deprivation-induced repression of mTORC1 was not responsible for the action of ULK1 on Sestrin2. Mass spectrometry analysis of Sestrin2 revealed three phosphorylation sites that are conserved across mammalian species. Mutation of the three sites to phospho-mimetic amino acids in exogenously expressed Sestrin2 promoted its interaction with GATOR2 and dramatically repressed mTORC1 even in the presence of leucine. Overall, the results support a model in which leucine selectively promotes dephosphorylation of Sestrin2, causing it to dissociate from and thereby activate GATOR2, leading to activation of mTORC1. PMID:27010498

  20. Dietary arachidonic acid dose-dependently increases the arachidonic acid concentration in human milk.

    PubMed

    Weseler, Antje R; Dirix, Chantal E H; Bruins, Maaike J; Hornstra, Gerard

    2008-11-01

    Lactation hampers normalization of the maternal arachidonic acid (AA) status, which is reduced after pregnancy and can further decline by the presently recommended increased consumption of (n-3) long-chain PUFA [(n-3) LCPUFA]. This may be unfavorable for breast-fed infants, because they also require an optimum supply of (n-6) LCPUFA. We therefore investigated the LCPUFA responses in nursing mothers upon increased consumption of AA and (n-3) LCPUFA. In a parallel, double-blind, controlled trial, lactating women received for 8 wk no extra LCPUFA (control group, n = 8), 200 (low AA group, n = 9), or 400 (high AA group, n = 8) mg/d AA in combination with (n-3) LCPUFA [320 mg/d docosahexaenoic acid (DHA), 80 mg/d eicosapentaenoic acid, and 80 mg/d other (n-3) fatty acids], or this dose of (n-3) LCPUFA alone [DHA + eicosapentaenoic acid group, n = 8]. Relative concentrations of AA, DHA, and sums of (n-6) and (n-3) LCPUFA were measured in milk total lipids (TL) and erythrocyte phospholipids (PL) after 2 and 8 wk and changes were compared by ANCOVA. The combined consumption of AA and (n-3) LCPUFA caused dose-dependent elevations of AA and total (n-6) LCPUFA concentrations in milk TL and did not significantly affect the DHA and total (n-3) LCPUFA increases caused by (n-3) LCPUFA supplementation only. This latter treatment did not significantly affect breast milk AA and total (n-6) LCPUFA concentrations. AA and DHA concentrations in milk TL and their changes were strongly and positively correlated with their corresponding values in erythrocyte PL (r(2) = 0.27-0.50; P dose dependently increased the AA concentration of their milk TL. PMID:18936218

  1. Leucine modulates peptide transport system-1 across the blood-brain barrier at the stereospecific site within the central nervous system.

    PubMed

    Banks, W A; Kastin, A J

    1991-04-01

    Previous results have shown that leucine injected into a cerebral ventricle (i.c.v.) can act as an allosteric regulator of peptide transport system-1 (PTS-1), the system that transports Tyr-Pro-Leu-Gly-NH2 (Tyr-MIF-1) and the enkephalins out of the central nervous system (CNS). D-Leucine appeared more potent than L-leucine. In the current study, dose-response curves were constructed for each compound after both intravenous (i.v.) and i.c.v. injection. Based on ED50 values after i.c.v. injection, D-leucine was about 200 times more potent than L-leucine in its inhibition of PTS-1, thereby confirming stereospecificity of the allosteric site. D- and L-Leucine were also more potent when given i.c.v. than when given i.v., suggesting that the site is located on the CNS side of the blood-brain barrier (BBB). The finding that D-leucine was less potent than L-leucine when given i.v. is also consistent with a CNS site of action because the L-isomer of leucine has been shown to be preferentially transported into the brain. These findings agree with the previous suggestion that some of the neurotoxic effects of leucine may be mediated through PTS-1 and could help explain how D-amino acids can exert opiate-related effects on the CNS. PMID:1676737

  2. Calculations of increased solar UV fluxes and DUV doses due to stratospheric-ozone depletions

    SciTech Connect

    Zardecki, A.; Gerstl, S.A.W.

    1982-02-01

    Accurate radiative transfer calculations are performed in the middle ultraviolet spectral region for aerosol-loaded atmospheres with the goal of determining the solar irradiance at the ground and quantifying the irradiance perturbations due to the presence of aerosols and various ozone depletions. The extent of the increase of UV-B radiation as a function of wave-length and solar zenith angle is calculated for five model atmospheres. In addition, the damaging ultraviolet dose rates and radiation amplification factors are evaluated at different latitudes and seasons for erythemal and DNA action spectra.

  3. Pharmacoepidemiology of opiate use in the Neonatal ICU: Increasing cumulative doses and iatrogenic opiate withdrawal

    PubMed Central

    Lewis, Tamorah; Erfe, Betty Luan; Ezell, Tarrah; Gauda, Estelle

    2015-01-01

    Objective Neonatal ICU care involves use of opiates to treat post-operative, ventilated or chronically ill infants. Opiates provide necessary analgesia and sedation, but the morbidities include prolonged Neonatal Abstinence Syndrome (NAS) and extended length of stay for dose tapering. Our objective was to quantify trends in opiate exposure in a tertiary care NICU. We hypothesize that medical opiate exposure and resultant ICU-acquired NAS would increase over time. Design retrospective cross-sectional cohort study Setting tertiary care NICU Patients high risk inborn infants admitted in fiscal years 2003–2004, 2007–2008 and 2010–2011 Main Outcome Measure Average cumulative morphine exposure (all opiate doses converted to morphine equivalents) per time epoch was compared in cohorts of clinically similar infants. Linear regression was used to assess the primary outcome, assessing changes in opiate exposure over time. Results 63 infants were included in the final analysis. The primary analysis assessing cumulative opiate exposure per infant showed an increase of 134 mg per time epoch (95% CI −12, 279 mg, p-value 0.071). There was a statistically significant increase in the percent of infants with a diagnosis of iatrogenic NAS, increasing from 9 to 35 to 50% (p-value 0.012). Conclusion Medical opiate exposure is increasing over time in ICU infants. In association, there are increased diagnoses of ICU-acquired NAS. This trend should be monitored closely and further studies to assess interventions including more strident pain and sedation monitoring, weaning protocols and other efforts to decrease opiate exposure are warranted. PMID:26312957

  4. Leucine metabolism in rat liver after a bolus injection of endotoxin.

    PubMed

    Holecek, M; Sprongl, L; Tichý, M; Pecka, M

    1998-06-01

    To evaluate the contribution of hepatic tissue to alterations in the metabolism of proteins and the branched-chain amino acids (BCAA) leucine, isoleucine, and valine in systemic inflammatory response syndrome, we studied the changes of leucine metabolism in isolated perfused liver (IPL) of endotoxin-treated rats. Male albino rats were injected with the endotoxin of Salmonella enteritidis (5 mg x kg(-1)) or saline (control). Four hours later, leucine and ketoisocaproate (KIC) oxidation and incorporation into liver proteins were determined in IPL using the single-pass liver perfusion technique. L-[1-(14)C]leucine and alpha-keto[1-(14)C]isocaproic acid were used as a tracer in two separate experiments. Endotoxin treatment resulted in a decrease of plasma BCAA levels, an increase of leucine oxidation, and a decrease of KIC oxidation by IPL. Leucine incorporation into liver proteins was lower in endotoxin-treated rats, and we did not find measurable incorporation of the labeled carbon of KIC in liver proteins in either group of animals. The sum of individual amino acid concentrations in the effluent perfusate was higher in endotoxin-treated animals, although only leucine and phenylalanine increased significantly. The decrease in KIC oxidation indicates a decreased capacity of hepatic tissue to oxidize branched-chain ketoacids (BCKA). The increase in leucine oxidation by IPL of endotoxin-treated rats indicates an increase in BCAA aminotransferase activity. These changes demonstrate an important response of the body that enables the resynthesis of essential BCAA from their ketoanalogs delivered to the liver from peripheral tissues, particularly muscle. PMID:9627366

  5. Desensitization Using Bortezomib and High-dose Immunoglobulin Increases Rate of Deceased Donor Kidney Transplantation.

    PubMed

    Jeong, Jong Cheol; Jambaldorj, Enkthuya; Kwon, Hyuk Yong; Kim, Myung-Gyu; Im, Hye Jin; Jeon, Hee Jung; In, Ji Won; Han, Miyeun; Koo, Tai Yeon; Chung, Junho; Song, Eun Young; Ahn, Curie; Yang, Jaeseok

    2016-02-01

    Combination therapy of intravenous immunoglobulin (IVIG) and rituximab showed a good transplant rate in highly sensitized wait-listed patients for deceased donor kidney transplantation (DDKT), but carried the risk of antibody-mediated rejection. The authors investigated the impact of a new combination therapy of bortezomib, IVIG, and rituximab on transplantation rate.This study was a prospective, open-labeled clinical trial. The desensitization regimen consisted of 2 doses of IVIG (2  g/kg), a single dose of rituximab (375  mg/m), and 4 doses of bortezomib (1.3  mg/m). The transplant rate was analyzed. Anti-Human leukocyte antigen (HLA) DRB antibodies were determined by a Luminex solid-phase bead assay at baseline and after 2, 3, and 6 months in the desensitized patients.There were 19 highly sensitized patients who received desensitization and 17 patients in the control group. Baseline values of class I and II panel reactive antibody (%, peak mean fluorescence intensity) were 83  ±  16.0 (14952  ±  5820) and 63  ±  36.0 (10321  ±  7421), respectively. Deceased donor kidney transplantation was successfully performed in 8 patients (42.1%) in the desensitization group versus 4 (23.5%) in the control group. Multivariate time-varying covariate Cox regression analysis showed that desensitization increased the probability of DDKT (hazard ratio, 46.895; 95% confidence interval, 3.468-634.132; P = 0.004). Desensitization decreased mean fluorescence intensity values of class I panel reactive antibody by 15.5% (20.8%) at 2 months. In addition, a liberal mismatch strategy in post hoc analysis increased the benefit of desensitization in donor-specific antibody reduction. Desensitization was well tolerated, and acute rejection occurred only in the control group.In conclusion, a desensitization protocol using bortezomib, high-dose IVIG, and rituximab increased the DDKT rate in highly sensitized, wait-listed patients. PMID:26844479

  6. Desensitization Using Bortezomib and High-dose Immunoglobulin Increases Rate of Deceased Donor Kidney Transplantation

    PubMed Central

    Jeong, Jong Cheol; Jambaldorj, Enkthuya; Kwon, Hyuk Yong; Kim, Myung-Gyu; Im, Hye Jin; Jeon, Hee Jung; In, Ji Won; Han, Miyeun; Koo, Tai Yeon; Chung, Junho; Song, Eun Young; Ahn, Curie; Yang, Jaeseok

    2016-01-01

    Abstract Combination therapy of intravenous immunoglobulin (IVIG) and rituximab showed a good transplant rate in highly sensitized wait-listed patients for deceased donor kidney transplantation (DDKT), but carried the risk of antibody-mediated rejection. The authors investigated the impact of a new combination therapy of bortezomib, IVIG, and rituximab on transplantation rate. This study was a prospective, open-labeled clinical trial. The desensitization regimen consisted of 2 doses of IVIG (2 g/kg), a single dose of rituximab (375 mg/m2), and 4 doses of bortezomib (1.3 mg/m2). The transplant rate was analyzed. Anti-Human leukocyte antigen (HLA) DRB antibodies were determined by a Luminex solid-phase bead assay at baseline and after 2, 3, and 6 months in the desensitized patients. There were 19 highly sensitized patients who received desensitization and 17 patients in the control group. Baseline values of class I and II panel reactive antibody (%, peak mean fluorescence intensity) were 83 ± 16.0 (14952 ± 5820) and 63 ± 36.0 (10321 ± 7421), respectively. Deceased donor kidney transplantation was successfully performed in 8 patients (42.1%) in the desensitization group versus 4 (23.5%) in the control group. Multivariate time-varying covariate Cox regression analysis showed that desensitization increased the probability of DDKT (hazard ratio, 46.895; 95% confidence interval, 3.468–634.132; P = 0.004). Desensitization decreased mean fluorescence intensity values of class I panel reactive antibody by 15.5% (20.8%) at 2 months. In addition, a liberal mismatch strategy in post hoc analysis increased the benefit of desensitization in donor-specific antibody reduction. Desensitization was well tolerated, and acute rejection occurred only in the control group. In conclusion, a desensitization protocol using bortezomib, high-dose IVIG, and rituximab increased the DDKT rate in highly sensitized, wait-listed patients. PMID:26844479

  7. A Randomized Controlled Trial of Increased Dose and Frequency of Albendazole with Standard Dose DEC for Treatment of Wuchereria bancrofti Microfilaremics in Odisha, India

    PubMed Central

    Kerketa, Anna Salomi; Maharana, Antaryami; Panda, Sudanshu S; Mohanty, Prafulla Chandra; Horton, John; Ramachandran, Cherubala P

    2015-01-01

    Although current programmes to eliminate lymphatic filariasis have made significant progress it may be necessary to use different approaches to achieve the global goal, especially where compliance has been poor and ‘hot spots’ of continued infection exist. In the absence of alternative drugs, the use of higher or more frequent dosing with the existing drugs needs to be explored. We examined the effect of higher and/or more frequent dosing with albendazole with a fixed 300mg dose of diethylcarbamazine in a Wuchereria bancrofti endemic area in Odisha, India. Following screening, 104 consenting adults were randomly assigned to treatment with the standard regimen annually for 24 months (S1), or annually with increased dose (800mg albendazole)(H1) or with increased frequency (6 monthly) with either standard (S2) or increased (H2) dose. Pre-treatment microfilaria counts (GM) ranged from 348 to 459 mf/ml. Subjects were followed using microfilaria counts, OG4C3 antigen levels and ultrasound scanning for adult worm nests. Microfilarial counts tended to decrease more rapidly with higher or more frequent dosing at all time points. At 12 months, Mf clearance was marginally greater with the high dose regimens, while by 24 months, there was a trend to higher Mf clearance in the arm with increased frequency and 800mg of albendazole (76.9%) compared to other arms, (S1:64%, S2:69.2% & H1:73.1%). Although higher and/or more frequent dosing showed a trend towards a greater decline in antigenemia and clearance of “nests”, all regimens demonstrated the potential macrofilaricidal effect of the combination. The higher doses of albendazole did not result in a greater number or more severe side effects. The alternative regimens could be useful in the later stages of existing elimination programmes or achieving elimination more rapidly in areas where programmes have yet to start. PMID:25781977

  8. A randomized controlled trial of increased dose and frequency of albendazole with standard dose DEC for treatment of Wuchereria bancrofti microfilaremics in Odisha, India.

    PubMed

    Kar, Shantanu Kumar; Dwibedi, Bhagirathi; Kerketa, Anna Salomi; Maharana, Antaryami; Panda, Sudanshu S; Mohanty, Prafulla Chandra; Horton, John; Ramachandran, Cherubala P

    2015-03-01

    Although current programmes to eliminate lymphatic filariasis have made significant progress it may be necessary to use different approaches to achieve the global goal, especially where compliance has been poor and 'hot spots' of continued infection exist. In the absence of alternative drugs, the use of higher or more frequent dosing with the existing drugs needs to be explored. We examined the effect of higher and/or more frequent dosing with albendazole with a fixed 300 mg dose of diethylcarbamazine in a Wuchereria bancrofti endemic area in Odisha, India. Following screening, 104 consenting adults were randomly assigned to treatment with the standard regimen annually for 24 months (S1), or annually with increased dose (800 mg albendazole)(H1) or with increased frequency (6 monthly) with either standard (S2) or increased (H2) dose. Pre-treatment microfilaria counts (GM) ranged from 348 to 459 mf/ml. Subjects were followed using microfilaria counts, OG4C3 antigen levels and ultrasound scanning for adult worm nests. Microfilarial counts tended to decrease more rapidly with higher or more frequent dosing at all time points. At 12 months, Mf clearance was marginally greater with the high dose regimens, while by 24 months, there was a trend to higher Mf clearance in the arm with increased frequency and 800 mg of albendazole (76.9%) compared to other arms, (S1:64%, S2:69.2% & H1:73.1%). Although higher and/or more frequent dosing showed a trend towards a greater decline in antigenemia and clearance of "nests", all regimens demonstrated the potential macrofilaricidal effect of the combination. The higher doses of albendazole did not result in a greater number or more severe side effects. The alternative regimens could be useful in the later stages of existing elimination programmes or achieving elimination more rapidly in areas where programmes have yet to start. PMID:25781977

  9. Subpressor doses of angiotensin II do not increase albumin excretion in humans.

    PubMed

    Erley, C M; Grau, C; Furian, T C; Wolf, S; Braun, N; Risler, T

    1996-11-01

    The objective of our study was to evaluate the effects of subpressor doses of angiotensin II and mild physical stress on renal hemodynamics and urinary albumin excretion (UAE) in a group of young patients with essential hypertension compared to normotensive subjects. Eleven patients (26 +/- 6 years) and ten healthy control persons (25 +/- 2 years) were enrolled in the study. Secondary forms of hypertension had been excluded. Angiotensin II was infused at a dose of 0.3 and 1.0 ng/kg/min and physical stress testing was done with a cycle ergometer (50 W at 10 min for hypertensives, 100 W at 10 min for normotensives). Renal hemodynamics were assessed by clearance techniques (continuous insulin and p-aminohippurate clearance). Mean arterial pressure (MAP) and UAE were significantly higher in the hypertensive group than in normotensive control persons at any time of measurement. There was no significant increase in MAP or UAE under angiotensin II infusion either in the hypertensive group or in the normotensive group. MAP increased significantly under physical stress in the normotensive group only (83 +/- 7 mmHg baseline vs. 108 +/- mmHg during physical stress, p < 0.05). Angiotensin II infusion resulted in a significant change concerning renal hemodynamics in the hypertensive group only. The filtration fraction increased (18 +/- 3% baseline vs. 25 +/- 7% under infusion of 1.0 ng/kg/min angiotensin II, p < 0.05) due to a decline in ERPF and an increase in GFR in the hypertensive group. The amount of UAE correlated with the magnitude of the MAP in both groups. No correlation was found between renal hemodynamic parameters and the UAE. A significant correlation was found between the norepinephrine levels and the UAE in the control group. We could not demonstrate an albuminuric effect of subpressor doses of angiotensin II in normotensive or hypertensive subjects despite its well known effects on renal hemodynamics with an increase of the filtration fraction. These data

  10. Study on increasing production of natural silk by using low dose irradiation

    SciTech Connect

    Ruiying, Z.; Yinfen, Z.; Dingzhu, C.; Jinxian, R.

    1985-01-01

    Radiation effect on silkworm irradiated by low dose fast neutron and ..gamma..-ray emitted from Ra-Be neutron source are reported. It is shown that increasing production of natural silk can only be obtained by irradiation under specified conditions. It was found that an appropriate fluence employed could lead to increase hatching rate of silkworm eggs, make silkworms' bodies strong, grow fast, possess high disease resistance and reduce the whole stadium by 1/2 to 2 1/2 days. In addition, the irradiated silkworm can be expected to spin bigger cocoons with thick layers and the quality of cocoon silk are remarkable improved. The application of irradiation technique has now been extended to the suburbs of Beijing and welcomed by sericulturist.

  11. Leptin Signaling Is Required for Leucine Deprivation-enhanced Energy Expenditure*

    PubMed Central

    Zhang, Qian; Liu, Bin; Cheng, Ying; Meng, Qingshu; Xia, Tingting; Jiang, Lei; Chen, Shanghai; Liu, Yong; Guo, Feifan

    2014-01-01

    Leptin signaling in the hypothalamus is crucial in energy homeostasis. We have previously shown that dietary deprivation of the essential amino acid leucine in mice stimulates fat loss by increasing energy expenditure. The involvement of leptin signaling in this regulation, however, has not been reported. Here, we show that leucine deprivation promotes leptin signaling in mice maintained on an otherwise normal diet and restores leptin responses in mice maintained on a high fat diet, a regimen known to induce leptin resistance. In addition, we found that leucine deprivation stimulated energy expenditure, and fat loss was largely blocked in db/db mice homozygous for a mutation in leptin receptor and a knock-in mouse line Y3F with abrogation of leptin receptor Tyr1138-mediated signal transducer and activator transcript 3 signaling. Overall, our studies describe a novel link between hypothalamic leptin signaling and stimulation of energy expenditure under leucine deprivation. PMID:24302741

  12. Ozone Inhalation Leads to a Dose-Dependent Increase of Cytogenetic Damage in Human Lymphocytes

    PubMed Central

    Holland, Nina; Davé, Veronica; Venkat, Subha; Wong, Hofer; Donde, Aneesh; Balmes, John R; Arjomandi, Mehrdad

    2014-01-01

    Ozone is an important constituent of ambient air pollution and represents a major public health concern. Oxidative injury due to ozone inhalation causes the generation of reactive oxygen species and can be genotoxic. To determine whether ozone exposure causes genetic damage in peripheral blood lymphocytes, we employed a well-validated cytokinesis-block micronucleus Cytome assay. Frequencies of micronuclei (MN) and nucleoplasmic bridges (NB) were used as indicators of cytogenetic damage. Samples were obtained from 22 non-smoking healthy subjects immediately before and 24-hr after controlled 4-hr exposures to filtered air, 100 ppb, and 200 ppb ozone while exercising in a repeated-measure study design. Inhalation of ozone at different exposure levels was associated with a significant dose-dependent increase in MN frequency (P < 0.0001) and in the number of cells with more than 1 MN per cell (P < 0.0005). Inhalation of ozone also caused an increase in the number of apoptotic cells (P = 0.002). Airway neutrophilia was associated with an increase in MN frequency (P = 0.033) independent of the direct effects of ozone exposure (P < 0.0001). We also observed significant increases in both MN and NB frequencies after exercise in filtered air, suggesting that physical activity is also an important inducer of oxidative stress. These results corroborate our previous findings that cytogenetic damage is associated with ozone exposure, and show that damage is dose-dependent. Further study of ozone-induced cytogenetic damage in airway epithelial cells could provide evidence for the role of oxidative injury in lung carcinogenesis, and help to address the potential public health implications of exposures to oxidant environments. PMID:25451016

  13. Relationships between leucine and the pancreatic exocrine function for improving starch digestibility in ruminants.

    PubMed

    Liu, K; Liu, Y; Liu, S M; Xu, M; Yu, Z P; Wang, X; Cao, Y C; Yao, J H

    2015-04-01

    Four Holstein heifers (215 ± 7 kg; means ± SD), fitted with one pancreatic pouch, duodenal re-entrant cannulas, and duodenal infusion catheters, were used in this experiment. In phase 1, the 24-h profile of pancreatic fluid was determined. Pancreatic fluid flow peaked 1h after feeding, but peaks of similar magnitude also occurred before the morning feed, necessitating 24-h collection of pancreatic fluid to estimate daily excretion. In phase 2, the effects of duodenal infusions of 0, 10, 20, or 30 g of leucine on pancreatic fluid flow were determined in a 4 × 4 Latin square design. The leucine was infused for 12h in 2,500 mL of the infusate, and samples of pancreatic fluid and jugular blood were collected in 1-h intervals from the beginning of the infusion for 36 h. The results showed that the secretion rate of pancreatic fluid (mL/h) was significantly higher in 10-g leucine group than the other groups (mL/h). Protein concentration (mg/mL) in pancreatic fluid was elevated proportional to the amount of leucine infused. Leucine infusions increased both the concentration (U/mL) and secretion rate (U/h) of α-amylase. Infusion of 10 g of leucine also increased the secretion rates (U/h) of trypsin, chymotrypsin, and lipase, but did not change their concentrations. No significant effects of leucine infusions on plasma glucose and insulin concentrations were found. The results indicate that leucine could act as a nutrient signal to stimulate α-amylase production and pancreatic exocrine function in dairy heifers. PMID:25648818

  14. Diurnal variation in glucose and leucine metabolism in non-insulin-dependent diabetes.

    PubMed

    Umpleby, A M; Scobie, I N; Boroujerdi, M A; Carson, E R; Sonksen, P H

    1990-04-01

    Glucose and leucine metabolism were investigated in 5 poorly controlled non-insulin-dependent diabetics (NIDDM) following an i.v. injection of 3-[3H]glucose and 1-[14C]leucine in the morning and evening. In the morning glucose concentration (11.2 +/- 0.8 mmol/l) (mean +/- SEM) and production rate (14.2 +/- 1.3 mumol/min/kg) were significantly greater (P less than 0.001, P less than 0.05) and glucose metabolic clearance rate (MCR) (1.3 +/- 0.2 ml/min/kg) significantly lower (P less than 0.05) than in a group of control subjects. Glucose concentration was lower in the evening (P less than 0.05) as a result of a decrease in glucose production rate (P less than 0.05). Leucine concentration and production rate were not significantly different from normal but leucine oxidation rate was increased (P less than 0.05). There was no diurnal variation in leucine metabolism. Since leucine production is a measure of protein breakdown, the higher morning glucose production rate was not due to an increased supply of gluconeogenic precursors from protein catabolism. PMID:2190784

  15. Leucine Promotes Proliferation and Differentiation of Primary Preterm Rat Satellite Cells in Part through mTORC1 Signaling Pathway

    PubMed Central

    Dai, Jie-Min; Yu, Mu-Xue; Shen, Zhen-Yu; Guo, Chu-Yi; Zhuang, Si-Qi; Qiu, Xiao-Shan

    2015-01-01

    Signaling through the mammalian target of rapamycin (mTOR) in response to leucine modulates many cellular and developmental processes. However, in the context of satellite cell proliferation and differentiation, the role of leucine and mTORC1 is less known. This study investigates the role of leucine in the process of proliferation and differentiation of primary preterm rat satellite cells, and the relationship with mammalian target of rapamycin complex 1 (mTORC1) activation. Dissociation of primary satellite cells occurred with type I collagenase and trypsin, and purification, via different speed adherence methods. Satellite cells with positive expression of Desmin were treated with leucine and rapamycin. We observed that leucine promoted proliferation and differentiation of primary satellite cells and increased the phosphorylation of mTOR. Rapamycin inhibited proliferation and differentiation, as well as decreased the phosphorylation level of mTOR. Furthermore, leucine increased the expression of MyoD and myogenin while the protein level of MyoD decreased due to rapamycin. However, myogenin expressed no affect by rapamycin. In conclusion, leucine may up-regulate the activation of mTORC1 to promote proliferation and differentiation of primary preterm rat satellite cells. We have shown that leucine promoted the differentiation of myotubes in part through the mTORC1-MyoD signal pathway. PMID:26007333

  16. Extracting the normal lung dose-response curve from clinical DVH data: a possible role for low dose hyper-radiosensitivity, increased radioresistance

    NASA Astrophysics Data System (ADS)

    Gordon, J. J.; Snyder, K.; Zhong, H.; Barton, K.; Sun, Z.; Chetty, I. J.; Matuszak, M.; Ten Haken, R. K.

    2015-09-01

    In conventionally fractionated radiation therapy for lung cancer, radiation pneumonitis’ (RP) dependence on the normal lung dose-volume histogram (DVH) is not well understood. Complication models alternatively make RP a function of a summary statistic, such as mean lung dose (MLD). This work searches over damage profiles, which quantify sub-volume damage as a function of dose. Profiles that achieve best RP predictive accuracy on a clinical dataset are hypothesized to approximate DVH dependence. Step function damage rate profiles R(D) are generated, having discrete steps at several dose points. A range of profiles is sampled by varying the step heights and dose point locations. Normal lung damage is the integral of R(D) with the cumulative DVH. Each profile is used in conjunction with a damage cutoff to predict grade 2 plus (G2+) RP for DVHs from a University of Michigan clinical trial dataset consisting of 89 CFRT patients, of which 17 were diagnosed with G2+ RP. Optimal profiles achieve a modest increase in predictive accuracy—erroneous RP predictions are reduced from 11 (using MLD) to 8. A novel result is that optimal profiles have a similar distinctive shape: enhanced damage contribution from low doses (<20 Gy), a flat contribution from doses in the range ~20-40 Gy, then a further enhanced contribution from doses above 40 Gy. These features resemble the hyper-radiosensitivity / increased radioresistance (HRS/IRR) observed in some cell survival curves, which can be modeled using Joiner’s induced repair model. A novel search strategy is employed, which has the potential to estimate RP dependence on the normal lung DVH. When applied to a clinical dataset, identified profiles share a characteristic shape, which resembles HRS/IRR. This suggests that normal lung may have enhanced sensitivity to low doses, and that this sensitivity can affect RP risk.

  17. Isolation and characterization of awamori yeast mutants with L-leucine accumulation that overproduce isoamyl alcohol.

    PubMed

    Takagi, Hiroshi; Hashida, Keisuke; Watanabe, Daisuke; Nasuno, Ryo; Ohashi, Masataka; Iha, Tomoya; Nezuo, Maiko; Tsukahara, Masatoshi

    2015-02-01

    Awamori shochu is a traditional distilled alcoholic beverage made from steamed rice in Okinawa, Japan. Although it has a unique aroma that is distinguishable from that of other types of shochu, no studies have been reported on the breeding of awamori yeasts. In yeast, isoamyl alcohol (i-AmOH), known as the key flavor of bread, is mainly produced from α-ketoisocaproate in the pathway of L-leucine biosynthesis, which is regulated by end-product inhibition of α-isopropylmalate synthase (IPMS). Here, we isolated mutants resistant to the L-leucine analog 5,5,5-trifluoro-DL-leucine (TFL) derived from diploid awamori yeast of Saccharomyces cerevisiae. Some of the mutants accumulated a greater amount of intracellular L-leucine, and among them, one mutant overproduced i-AmOH in awamori brewing. This mutant carried an allele of the LEU4 gene encoding the Ser542Phe/Ala551Val variant IPMS, which is less sensitive to feedback inhibition by L-leucine. Interestingly, we found that either of the constituent mutations (LEU4(S542F) and LEU4(A551V)) resulted in the TFL tolerance of yeast cells and desensitization to L-leucine feedback inhibition of IPMS, leading to intracellular L-leucine accumulation. Homology modeling also suggested that L-leucine binding was drastically inhibited in the Ser542Phe, Ala551Val, and Ser542Phe/Ala551Val variants due to steric hindrance in the cavity of IPMS. As we expected, awamori yeast cells expressing LEU4(S542F), LEU4(A551V), and LEU4(S542F/A551V) showed a prominent increase in extracellular i-AmOH production, compared with that of cells carrying the vector only. The approach described here could be a practical method for the breeding of novel awamori yeasts to expand the diversity of awamori taste and flavor. PMID:25060730

  18. Directed evolution of leucine dehydrogenase for improved efficiency of L-tert-leucine synthesis.

    PubMed

    Zhu, Lin; Wu, Zhe; Jin, Jian-Ming; Tang, Shuang-Yan

    2016-07-01

    L-tert-Leucine and its derivatives are used as synthetic building blocks for pharmaceutical active ingredients, chiral auxiliaries, and ligands. Leucine dehydrogenase (LeuDH) is frequently used to prepare L-tert-leucine from the α-keto acid precursor trimethylpyruvate (TMP). In this study, a high-throughput screening method for the L-tert-leucine synthesis reaction based on a spectrophotometric approach was developed. Directed evolution strategy was applied to engineer LeuDH from Lysinibacillus sphaericus for improved efficiency of L-tert-leucine synthesis. After two rounds of random mutagenesis, the specific activity of LeuDH on the substrate TMP was enhanced by more than two-fold, compared with that of the wild-type enzyme, while the activity towards its natural substrate, leucine, decreased. The catalytic efficiencies (k cat/K m) of the best mutant enzyme, H6, on substrates TMP and NADH were all enhanced by more than five-fold as compared with that of the wild-type enzyme. The efficiency of L-tert-leucine synthesis by mutant H6 was significantly improved. A productivity of 1170 g/l/day was achieved for the mutant enzyme H6, compared with 666 g/l/day for the wild-type enzyme. PMID:26898942

  19. The SOS response increases bacterial fitness, but not evolvability, under a sublethal dose of antibiotic

    PubMed Central

    Torres-Barceló, Clara; Kojadinovic, Mila; Moxon, Richard; MacLean, R. Craig

    2015-01-01

    Exposure to antibiotics induces the expression of mutagenic bacterial stress–response pathways, but the evolutionary benefits of these responses remain unclear. One possibility is that stress–response pathways provide a short-term advantage by protecting bacteria against the toxic effects of antibiotics. Second, it is possible that stress-induced mutagenesis provides a long-term advantage by accelerating the evolution of resistance. Here, we directly measure the contribution of the Pseudomonas aeruginosa SOS pathway to bacterial fitness and evolvability in the presence of sublethal doses of ciprofloxacin. Using short-term competition experiments, we demonstrate that the SOS pathway increases competitive fitness in the presence of ciprofloxacin. Continued exposure to ciprofloxacin results in the rapid evolution of increased fitness and antibiotic resistance, but we find no evidence that SOS-induced mutagenesis accelerates the rate of adaptation to ciprofloxacin during a 200 generation selection experiment. Intriguingly, we find that the expression of the SOS pathway decreases during adaptation to ciprofloxacin, and this helps to explain why this pathway does not increase long-term evolvability. Furthermore, we argue that the SOS pathway fails to accelerate adaptation to ciprofloxacin because the modest increase in the mutation rate associated with SOS mutagenesis is offset by a decrease in the effective strength of selection for increased resistance at a population level. Our findings suggest that the primary evolutionary benefit of the SOS response is to increase bacterial competitive ability, and that stress-induced mutagenesis is an unwanted side effect, and not a selected attribute, of this pathway. PMID:26446807

  20. Minimal skin dose increase in longitudinal rotating biplanar linac-MR systems: examination of radiation energy and flattening filter design

    NASA Astrophysics Data System (ADS)

    Keyvanloo, A.; Burke, B.; St. Aubin, J.; Baillie, D.; Wachowicz, K.; Warkentin, B.; Steciw, S.; Fallone, B. G.

    2016-05-01

    The magnetic fields of linac-MR systems modify the path of contaminant electrons in photon beams, which alters patient entrance skin dose. Also, the increased SSD of linac-MR systems reduces the maximum achievable dose rate. To accurately quantify the changes in entrance skin dose, the authors use EGSnrc Monte Carlo calculations that incorporate 3D magnetic field of the Alberta 0.5 T longitudinal linac-MR system. The Varian 600C linac head geometry assembled on the MRI components is used in the BEAMnrc simulations for 6 MV and 10 MV beam models and skin doses are calculated at an average depth of 70 μm using DOSXYZnrc. 3D modeling shows that magnetic fringe fields decay rapidly and are small at the linac head. SSDs between 100 and 120 cm result in skin-dose increases of between ~6%–19% and ~1%–9% for the 6 and 10 MV beams, respectively. For 6 MV, skin dose increases from ~10.5% to ~1.5% for field-size increases of 5  ×  5 cm2 to 20  ×  20 cm2. For 10 MV, skin dose increases by ~6% for a 5  ×  5 cm2 field, and decreases by ~1.5% for a 20  ×  20 cm2 field. Furthermore, the proposed reshaped flattening filter increases the dose rate from the current 355 MU min‑1 to 529 MU min‑1 (6 MV) or 604 MU min‑1 (10 MV), while the skin-dose increases by only an additional ~2.6% (all percent increases in skin dose are relative to D max). This study suggests that there is minimal increase in the entrance skin dose and minimal/no decrease in the dose rate of the Alberta longitudinal linac-MR system. The even lower skin dose increase at 10 MV offers further advantages in future designs of linac-MR prototypes.

  1. Minimal skin dose increase in longitudinal rotating biplanar linac-MR systems: examination of radiation energy and flattening filter design.

    PubMed

    Keyvanloo, A; Burke, B; St Aubin, J; Baillie, D; Wachowicz, K; Warkentin, B; Steciw, S; Fallone, B G

    2016-05-01

    The magnetic fields of linac-MR systems modify the path of contaminant electrons in photon beams, which alters patient entrance skin dose. Also, the increased SSD of linac-MR systems reduces the maximum achievable dose rate. To accurately quantify the changes in entrance skin dose, the authors use EGSnrc Monte Carlo calculations that incorporate 3D magnetic field of the Alberta 0.5 T longitudinal linac-MR system. The Varian 600C linac head geometry assembled on the MRI components is used in the BEAMnrc simulations for 6 MV and 10 MV beam models and skin doses are calculated at an average depth of 70 μm using DOSXYZnrc. 3D modeling shows that magnetic fringe fields decay rapidly and are small at the linac head. SSDs between 100 and 120 cm result in skin-dose increases of between ~6%-19% and ~1%-9% for the 6 and 10 MV beams, respectively. For 6 MV, skin dose increases from ~10.5% to ~1.5% for field-size increases of 5  ×  5 cm(2) to 20  ×  20 cm(2). For 10 MV, skin dose increases by ~6% for a 5  ×  5 cm(2) field, and decreases by ~1.5% for a 20  ×  20 cm(2) field. Furthermore, the proposed reshaped flattening filter increases the dose rate from the current 355 MU min(-1) to 529 MU min(-1) (6 MV) or 604 MU min(-1) (10 MV), while the skin-dose increases by only an additional ~2.6% (all percent increases in skin dose are relative to D max). This study suggests that there is minimal increase in the entrance skin dose and minimal/no decrease in the dose rate of the Alberta longitudinal linac-MR system. The even lower skin dose increase at 10 MV offers further advantages in future designs of linac-MR prototypes. PMID:27050044

  2. Sustained delivery by leucine-modified chitosan spray-dried respirable powders.

    PubMed

    Learoyd, Tristan P; Burrows, Jane L; French, Eddie; Seville, Peter C

    2009-05-01

    The controlled co-delivery of multiple agents to the lung offers potential benefits to patients. This study investigated the preparation and characterisation of highly respirable spray-dried powders displaying the sustained release of two chemically distinct therapeutic agents. Spray-dried powders were produced from 30% (v/v) aqueous ethanol formulations that contained hydrophilic (terbutaline sulphate) and hydrophobic (beclometasone dipropionate) model drugs, chitosan (as a drug release modifier) and leucine (aerosolisation enhancer). The influence of chitosan molecular weight on spray-drying thermal efficiency, aerosol performance and drug release profile was investigated. Resultant powders were physically characterised: with in vitro aerosolisation performance and drug release profile investigated by the Multi-Stage Liquid Impinger and modified USP II dissolution apparatus, respectively. It was found that increased chitosan molecular weight gave increased spray-drying thermal efficiency. The powders generated were of a suitable size for inhalation-with emitted doses over 90% and fine particle fractions up to 72% of the loaded dose. Sustained drug release profiles were observed in dissolution tests for both agents: increased chitosan molecular weight associated with increased duration of drug release. The controlled co-delivery of hydrophilic and hydrophobic entities underlines the capability of spray drying to produce respirable particles with sustained release for delivery to the lung. PMID:19429272

  3. Leucine alleviates dexamethasone-induced suppression of muscle protein synthesis via synergy involvement of mTOR and AMPK pathways.

    PubMed

    Wang, Xiao J; Yang, Xin; Wang, Ru X; Jiao, Hong C; Zhao, Jing P; Song, Zhi G; Lin, Hai

    2016-07-01

    Glucocorticoids (GCs) are negative muscle protein regulators that contribute to the whole-body catabolic state during stress. Mammalian target of rapamycin (mTOR)-signalling pathway, which acts as a central regulator of protein metabolism, can be activated by branched-chain amino acids (BCAA). In the present study, the effect of leucine on the suppression of protein synthesis induced by GCs and the pathway involved were investigated. In vitro experiments were conducted using cultured C2C12 myoblasts to study the effect of GCs on protein synthesis, and the involvement of mTOR pathway was investigated as well. After exposure to dexamethasone (DEX, 100 μmol/l) for 24 h, protein synthesis in muscle cells was significantly suppressed (P<0.05), the phosphorylations of mTOR, ribosomal protein S6 protein kinase 1 (p70s6k1) and eukaryotic initiation factor 4E binding protein 1 (4EBP1) were significantly reduced (P<0.05). Leucine supplementation (5 mmol/l, 10 mmol/l and 15 mmol/l) for 1 h alleviated the suppression of protein synthesis induced by DEX (P<0.05) and was accompanied with the increased phosphorylation of mTOR and decreased phosphorylation of AMPK (P<0.05). Branched-chain amino transferase 2 (BCAT2) mRNA level was not influenced by DEX (P>0.05) but was increased by leucine supplementation at a dose of 5 mmol/l (P<0.05). PMID:27129299

  4. Ingestion of a moderately high caffeine dose before exercise increases postexercise energy expenditure.

    PubMed

    Fernández-Elías, Valentín E; Del Coso, Juan; Hamouti, Nassim; Ortega, Juan F; Muñoz, Gloria; Muñoz-Guerra, Jesus; Mora-Rodríguez, Ricardo

    2015-02-01

    Caffeine is an ergogenic aid widely used before and during prolonged exercise. Due to its prolonged biological half-life caffeine effects could remain after exercise. We aimed to investigate the metabolic, respiratory, and cardiovascular postexercise responses to preexercise graded caffeine ingestion. Twelve aerobically trained subjects (mean VO₂max = 54 ± 7 ml · min⁻¹ · kg⁻¹) cycled for 60-min at 75% VO₂max after ingesting placebo (0 mg of caffeine per kg of body weight) or 0.5, 1.5, 3.0 and 4.5 mg · kg⁻¹ on five occasions. During the 3 hr postexercise, heart rate, blood pressure, glucose, lactate, and fatty acids were analyzed. None of these variables were statistically affected by preexercise caffeine ingestion between 0.5 and 4.5 mg · kg⁻¹. However, ingestion of 4.5 mg · kg⁻¹ of caffeine raised postexercise energy expenditure 15% above placebo (233 ± 58 vs. 202 ± 49 kcal/3 hr; p < .05). Ventilation and tidal volume were elevated after the 4.5 mg · kg⁻¹ caffeine dose above placebo (9.2 ± 2.5 L · min⁻¹ and 0.67 ± 0.29 L · breath⁻¹ vs. 7.8 ± 1.5 L · min⁻¹ and 0.56 ± 0.20 L · breath⁻¹, respectively; p < .05). Ventilation correlated with tidal volume (r = .45; p < .05) and energy expenditure (r = .72; p < .05). In summary, preexercise ingestion of ergogenic caffeine doses do not alter postexercise cardiovascular responses. However, ingestion of 4.5 mg · kg⁻¹ of caffeine raises 3-hr postexercise energy expenditure (i.e., 31 kcal) likely through increased energy cost of ventilation. PMID:24901809

  5. Persistent increases in rat hypothalamic POMC gene expression following chronic withdrawal from chronic “binge” pattern escalating-dose, but not steady-dose, cocaine

    PubMed Central

    Zhou, Yan; Kreek, Mary Jeanne

    2016-01-01

    Recent research suggests an involvement of pro-opiomelanocortin (POMC) gene products (e.g., beta-endorphin) in modulating cocaine-induced reward and addiction-like behaviors in rodents. In this study, we investigated whether chronic “binge” cocaine and its withdrawal altered POMC gene expression in the brain of rats. Male Fischer rats were treated with two different chronic (14-day) “binge” pattern cocaine administration regimens (3 injections at 1-h intervals, i.p.): steady-dose (45 mg/kg/day) and escalating-dose (90 mg/kg on the last day). Although there was no POMC mRNA alteration after chronic steady-dose cocaine, a significant decrease in POMC mRNA levels in the hypothalamus was found after chronic escalating-dose cocaine. In contrast, after acute (1-day) withdrawal from chronic “binge” escalating-dose regimen, but not steady-dose regimen, there were increased hypothalamic POMC mRNA levels that persisted into 14 days of protracted withdrawal. To study the role of the endogenous opioid systems in the cocaine withdrawal effects, we administered a single naloxone injection (1 mg/kg) that caused an elevated POMC mRNA levels observed 24 h later in cocaine naïve rats, but it did not lead to further increases in cocaine-withdrawn rats. Our results suggest that during withdrawal from chronic “binge” escalating-dose cocaine: (1) there was a persistent increase in hypothalamic POMC gene expression; and (2) hyposensitivity of the POMC gene expression to naloxone indicates altered opioidergic tone at or above the hypothalamic level. PMID:25595971

  6. Increasing food deprivation relative to baseline influences D-amphetamine dose-response gradients.

    PubMed

    Lotfizadeh, Amin D; Zimmermann, Zachary J; Watkins, Erin E; Edwards, Timothy L; Poling, Alan

    2014-10-01

    Several studies using non-pharmacological discriminative stimuli have found that stimulus control, as evident in generalization gradients, changes when motivation for (i.e., deprivation of) the relevant reinforcer is altered. Drug-discrimination studies, however, have not consistently revealed such an effect. A procedural detail that may account for the lack of a reliable effect in drug-discrimination studies is that motivation was characteristically reduced relative to the training condition in these studies. The present experiment examined how substantially increasing motivation affects D-amphetamine discrimination. Rats initially were trained to discriminate D-amphetamine (1.0 mg/kg) from vehicle (0 mg/kg) injections under 22-h food deprivation conditions. Dose-response gradients were then obtained under 22-h and 46-h deprivation levels. The ED50 was significantly higher with greater deprivation. This finding suggests that increasing motivation relative to the training condition may reduce stimulus control by drugs, while decreasing it may sharpen stimulus control. PMID:25179163

  7. Increased thermal pain sensitivity in animals exposed to chronic high dose Vicodin but not pure hydrocodone.

    PubMed

    O'Connell, Thomas F; Carpenter, Patrick S; Caballero, Nadia; Putnam, Andrew J; Steere, Joshua T; Matz, Gregory J; Foecking, Eileen M

    2014-01-01

    Vicodin, the combination drug of acetaminophen and the opioid hydrocodone, is one of the most prescribed drugs on the market today. Opioids have demonstrated the ability to paradoxically cause increased pain sensitivity to users in a phenomena called opioid-induced hyperalgesia (OIH). While selected opioids have been shown to produce OIH symptoms in an animal model, hydrocodone and the combination drug Vicodin have yet to be studied. The purpose of this study was to explore the effect of exposure to chronic high dose Vicodin or its components on the sensitivity to both thermal and mechanical pain. Animals were randomly divided into 4 groups, Vicodin, acetaminophen, hydrocodone, or vehicle control, and administered the drug daily for 120 days. Rats were subsequently tested for thermal and mechanical sensitivity. The rats in the Vicodin group displayed a significant decrease in withdrawal time to thermal pain. The rats receiving acetaminophen, hydrocodone, and vehicle showed no statistically significant hypersensitivity in thermal testing. None of the groups demonstrated statistically significant hypersensitivity to mechanical testing. The data suggests Vicodin produces signs of OIH in a rodent model. However, increased pain sensitivity was only noted in the thermal pathway and the hypersensitivity was only seen with the opioid combination drug, not the opioid alone. The results of this study both support the results of previous rodent opioid studies while generating further questions about the specific properties of Vicodin that contribute to pain hypersensitivity. The growing use of Vicodin to treat chronic pain necessitates further research looking into this paradoxical pain response. PMID:25054394

  8. Neurotoxic Methamphetamine Doses Increase LINE-1 Expression in the Neurogenic Zones of the Adult Rat Brain

    PubMed Central

    Moszczynska, Anna; Flack, Amanda; Qiu, Ping; Muotri, Alysson R.; Killinger, Bryan A.

    2015-01-01

    Methamphetamine (METH) is a widely abused psychostimulant with the potential to cause neurotoxicity in the striatum and hippocampus. Several epigenetic changes have been described after administration of METH; however, there are no data regarding the effects of METH on the activity of transposable elements in the adult brain. The present study demonstrates that systemic administration of neurotoxic METH doses increases the activity of Long INterspersed Element (LINE-1) in two neurogenic niches in the adult rat brain in a promoter hypomethylation-independent manner. Our study also demonstrates that neurotoxic METH triggers persistent decreases in LINE-1 expression and increases the LINE-1 levels within genomic DNA in the striatum and dentate gyrus of the hippocampus, and that METH triggers LINE-1 retrotransposition in vitro. We also present indirect evidence for the involvement of glutamate (GLU) in LINE-1 activation. The results suggest that LINE-1 activation might occur in neurogenic areas in human METH users and might contribute to METH abuse-induced hippocampus-dependent memory deficits and impaired performance on several cognitive tasks mediated by the striatum. PMID:26463126

  9. Is increasing the dose of Entecavir effective in partial virological responders?

    PubMed Central

    Erturk, Ayse; Adnan Akdogan, Remzi; Parlak, Emine; Cure, Erkan; Cumhur Cure, Medine; Ozturk, Cinar

    2014-01-01

    Objective To analyze the effect of increasing Entecavir (ETV) dosage in patients with chronic hepatitis B (CHB) who partially responded to ETV after 1 year. Methods Twenty-three hepatitis B e antigen (HBeAg)-positive and 36 HBeAg-negative patients with CHB were treated with ETV 0.5 mg daily. After 1 year of the treatment, those with detectable hepatitis B virus (HBV-DNA) were randomized to either ETV 0.5 mg or 1 mg daily. The resistance to ETV was excluded. Both groups received ETV for 3 years. The groups were compared in aspects of undetectable DNA. Results Group 1 was given 0.5 mg ETV and included 32 patients (20 HBeAg-negative and 12 HBeAg-positive). Group 2 was given 1 mg ETV and consisted of 27 patients (16 HBeAg-negative and eleven HBeAg-positive). Group 2 had more effective suppression of HBV-DNA while both groups had comparable rates of HBeAg loss (58% and 63% for group 1 and group 2, respectively) and alanine transaminase (ALT) normalization at the end of 4 years. Conclusion Increasing ETV dose from 0.5 mg to 1 mg after 1 year of ETV treatment may provide an effective suppression of viral replication. PMID:24936126

  10. A SINGLE HIGH DOSE OF METHAMPHETAMINE INCREASES COCAINE SELF-ADMINISTRATION BY DEPLETION OF STRIATAL DOPAMINE IN RATS

    PubMed Central

    XI, Z.-X.; KLEITZ, H. K.; DENG, X.; LADENHEIM, B.; PENG, X.-Q.; LI, X.; GARDNER, E. L.; STEIN, E. A.; CADET, J. L.

    2013-01-01

    Psychostimulant addicts often take high doses of drugs, and high doses of psychostimulants such as methamphetamine (METH) are neurotoxic to striatal dopamine (DA) terminals. Yet, the effects of high doses of METH on drug-seeking and drug-taking behavior have not been examined. In the present study, we found that single high doses of METH in rats (10–20 mg/kg) dose-dependently increased cocaine self-administration under fixed-ratio 2 (FR2) reinforcement conditions, while higher doses (40 mg/kg×1 or 10 mg/kg/2 h×4) caused high mortality among rats maintained on daily cocaine self-administration. The increased cocaine self-administration appeared to be a compensatory response to reduced cocaine reward after METH, because the same doses of METH caused a dose-dependent reduction both in “breakpoint” levels for cocaine self-administration under progressive-ratio reinforcement and in nucleus accumbens DA response to acute cocaine. Further, METH (10–20 mg/kg) produced large DA release (4000%–6000% over baseline), followed by a significant reduction in striatal DA and 3,4-dihydroxyphenylacetic acid (DOPAC) contents, but without significant changes in striatal DA transporter levels. These findings suggest that the present high doses of METH caused striatal DA depletion or hypofunction without severe damage in DA terminals, which may contribute to the increased cocaine-taking behavior observed in the present study. Provided that the present doses of METH may mimic METH overdose incidents in humans, the present findings suggest that METH-induced DA depletion or neurotoxicity may lead to an increase in subsequent drug-taking and drug-seeking behavior. PMID:19336247

  11. A single high dose of methamphetamine increases cocaine self-administration by depletion of striatal dopamine in rats.

    PubMed

    Xi, Z-X; Kleitz, H K; Deng, X; Ladenheim, B; Peng, X-Q; Li, X; Gardner, E L; Stein, E A; Cadet, J L

    2009-06-30

    Psychostimulant addicts often take high doses of drugs, and high doses of psychostimulants such as methamphetamine (METH) are neurotoxic to striatal dopamine (DA) terminals. Yet, the effects of high doses of METH on drug-seeking and drug-taking behavior have not been examined. In the present study, we found that single high doses of METH in rats (10-20 mg/kg) dose-dependently increased cocaine self-administration under fixed-ratio 2 (FR2) reinforcement conditions, while higher doses (40 mg/kgx1 or 10 mg/kg/2 hx4) caused high mortality among rats maintained on daily cocaine self-administration. The increased cocaine self-administration appeared to be a compensatory response to reduced cocaine reward after METH, because the same doses of METH caused a dose-dependent reduction both in "break-point" levels for cocaine self-administration under progressive-ratio reinforcement and in nucleus accumbens DA response to acute cocaine. Further, METH (10-20 mg/kg) produced large DA release (4000%-6000% over baseline), followed by a significant reduction in striatal DA and 3,4-dihydroxyphenylacetic acid (DOPAC) contents, but without significant changes in striatal DA transporter levels. These findings suggest that the present high doses of METH caused striatal DA depletion or hypofunction without severe damage in DA terminals, which may contribute to the increased cocaine-taking behavior observed in the present study. Provided that the present doses of METH may mimic METH overdose incidents in humans, the present findings suggest that METH-induced DA depletion or neurotoxicity may lead to an increase in subsequent drug-taking and drug-seeking behavior. PMID:19336247

  12. 21 CFR 582.5406 - Leucine.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Leucine. 582.5406 Section 582.5406 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements...

  13. 21 CFR 582.5406 - Leucine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Leucine. 582.5406 Section 582.5406 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements...

  14. Amino acid availability and age affect the leucine stimulation of protein synthesis and eIF4F formation in muscle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have previously shown that a physiological increase in plasma leucine for 60 and 120 min increases translation initiation factor activation in muscle of neonatal pigs. Although muscle protein synthesis is increased by leucine at 60 min, it is not maintained at 120 min, perhaps because of the decr...

  15. Beta-carotene conversion to vitamin A decreases as the dietary dose increases in humans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It has been suggested that high doses of B-carotene limit its conversion to vitamin A, yet this effect has not been well established in humans. A feeding study was conducted in which volunteers consumed two doses of deuterium labeled B-carotene on two occasions, with B-carotene and vitamin A respon...

  16. Fitness costs of increased cataract frequency and cumulative radiation dose in natural mammalian populations from Chernobyl

    PubMed Central

    Lehmann, Philipp; Boratyński, Zbyszek; Mappes, Tapio; Mousseau, Timothy A.; Møller, Anders P.

    2016-01-01

    A cataract is a clouding of the lens that reduces light transmission to the retina, and it decreases the visual acuity of the bearer. The prevalence of cataracts in natural populations of mammals, and their potential ecological significance, is poorly known. Cataracts have been reported to arise from high levels of oxidative stress and a major cause of oxidative stress is ionizing radiation. We investigated whether elevated frequencies of cataracts are found in eyes of bank voles Myodes glareolus collected from natural populations in areas with varying levels of background radiation in Chernobyl. We found high frequencies of cataracts in voles collected from different areas in Chernobyl. The frequency of cataracts was positively correlated with age, and in females also with the accumulated radiation dose. Furthermore, the number of offspring in female voles was negatively correlated with cataract severity. The results suggest that cataracts primarily develop as a function of ionizing background radiation, most likely as a plastic response to high levels of oxidative stress. It is therefore possible that the elevated levels of background radiation in Chernobyl affect the ecology and fitness of local mammals both directly through, for instance, reduced fertility and indirectly, through increased cataractogenesis. PMID:26814168

  17. Fitness costs of increased cataract frequency and cumulative radiation dose in natural mammalian populations from Chernobyl.

    PubMed

    Lehmann, Philipp; Boratyński, Zbyszek; Mappes, Tapio; Mousseau, Timothy A; Møller, Anders P

    2016-01-01

    A cataract is a clouding of the lens that reduces light transmission to the retina, and it decreases the visual acuity of the bearer. The prevalence of cataracts in natural populations of mammals, and their potential ecological significance, is poorly known. Cataracts have been reported to arise from high levels of oxidative stress and a major cause of oxidative stress is ionizing radiation. We investigated whether elevated frequencies of cataracts are found in eyes of bank voles Myodes glareolus collected from natural populations in areas with varying levels of background radiation in Chernobyl. We found high frequencies of cataracts in voles collected from different areas in Chernobyl. The frequency of cataracts was positively correlated with age, and in females also with the accumulated radiation dose. Furthermore, the number of offspring in female voles was negatively correlated with cataract severity. The results suggest that cataracts primarily develop as a function of ionizing background radiation, most likely as a plastic response to high levels of oxidative stress. It is therefore possible that the elevated levels of background radiation in Chernobyl affect the ecology and fitness of local mammals both directly through, for instance, reduced fertility and indirectly, through increased cataractogenesis. PMID:26814168

  18. Reduction in plasma leucine after sprint exercise is greater in males than in females.

    PubMed

    Esbjörnsson, M; Rooyackers, O; Norman, B; Rundqvist, H C; Nowak, J; Bülow, J; Simonsen, L; Jansson, E

    2012-06-01

    There is a pronounced gender difference in the accumulation of plasma ammonia after sprint exercise. Ammonia is a key intermediate in amino acid metabolism, which implies that gender-related differences in plasma and muscle amino acid concentrations after sprint exercise exist. To study this, three bouts of 30-s sprint exercise were performed by healthy females (n=8) and males (n=6). Blood leucine and muscle leucine were collected over the exercise period. Basal arterial plasma and skeletal muscle leucine were 40% higher in males than females (P<0.010 and P<0.020). Plasma, but not muscle, leucine decreased by sprint exercise and more so in males than females (g × t: P=0.025). Increase in ammonia was higher in males than females in both plasma and muscle (g × t: P<0.001 and P=0.003). An opposite pattern was shown for plasma glutamine, where an increase was found in females (P<0.001), but not in males. In conclusion, the lower plasma ammonia after sprint exercise in females seems to be explained by a lower accumulation of ammonia in skeletal muscle and by a buffering of ammonia in the form of glutamine in females. The greater reduction in plasma leucine in males seems to be related to their greater increase in muscle ammonia after sprint exercise. PMID:22612362

  19. Lowering photosensitizer doses and increasing fluences induce apoptosis in tumor bearing mice

    PubMed Central

    Haedicke, Katja; Graefe, Susanna; Teichgraeber, Ulf; Hilger, Ingrid

    2016-01-01

    The objective of this study was to determine an optimal dose of photodynamic therapy (PDT) for inducing apoptotic tumor cells in vivo. In this context, mice bearing human tongue-squamous epithelium carcinomas were treated with various photosensitizer concentrations and fluences. Tumor apoptosis was imaged after 2 days via a self-designed DY-734-annexin V probe using near-infrared fluorescence (NIRF) optical imaging. Apoptosis was verified ex vivo via TUNEL staining. Apoptotic tumor cells were detected in vivo at a dose of 40 µg photosensitizer and a fluency of 100 J/cm2. This is the lowest photosensitizer dose reported so far. PMID:27446695

  20. Low-dose ionizing radiation induces mitochondrial fusion and increases expression of mitochondrial complexes I and III in hippocampal neurons

    PubMed Central

    Chang, Chuang-Rung; Kao, Mou-Chieh; Chen, Kuan-Wei; Chiu, Shih-Che; Hsu, Ming-Ling; Hsiang, I-Chou; Chen, Yu-Jen; Chen, Linyi

    2015-01-01

    High energy ionizing radiation can cause DNA damage and cell death. During clinical radiation therapy, the radiation dose could range from 15 to 60 Gy depending on targets. While 2 Gy radiation has been shown to cause cancer cell death, studies also suggest a protective potential by low dose radiation. In this study, we examined the effect of 0.2-2 Gy radiation on hippocampal neurons. Low dose 0.2 Gy radiation treatment increased the levels of MTT. Since hippocampal neurons are post-mitotic, this result reveals a possibility that 0.2 Gy irradiation may increase mitochondrial activity to cope with stimuli. Maintaining neural plasticity is an energy-demanding process that requires high efficient mitochondrial function. We thus hypothesized that low dose radiation may regulate mitochondrial dynamics and function to ensure survival of neurons. Our results showed that five days after 0.2 Gy irradiation, no obvious changes on neuronal survival, neuronal synapses, membrane potential of mitochondria, reactive oxygen species levels, and mitochondrial DNA copy numbers. Interestingly, 0.2 Gy irradiation promoted the mitochondria fusion, resulting in part from the increased level of a mitochondrial fusion protein, Mfn2, and inhibition of Drp1 fission protein trafficking to the mitochondria. Accompanying with the increased mitochondrial fusion, the expressions of complexes I and III of the electron transport chain were also increased. These findings suggest that, hippocampal neurons undergo increased mitochondrial fusion to modulate cellular activity as an adaptive mechanism in response to low dose radiation. PMID:26415228

  1. Excess leucine intake enhances muscle anabolic signaling but not net protein anabolism in young men and women.

    PubMed

    Glynn, Erin L; Fry, Christopher S; Drummond, Micah J; Timmerman, Kyle L; Dhanani, Shaheen; Volpi, Elena; Rasmussen, Blake B

    2010-11-01

    Essential amino acids (EAA) stimulate skeletal muscle protein synthesis (MPS) in humans. Leucine may have a greater stimulatory effect on MPS than other EAA and/or decrease muscle protein breakdown (MPB). To determine the effect of 2 different leucine concentrations on muscle protein turnover and associated signaling, young men (n = 6) and women (n = 8) ingested 10 g EAA in 1 of 2 groups: composition typical of high quality proteins (CTRL; 1.8 g leucine) or increased leucine concentration (LEU; 3.5 g leucine). Participants were studied for 180 min postingestion. Fractional synthetic rate and leg phenylalanine and leucine kinetics were assessed on muscle biopsies using stable isotopic techniques. Signaling was determined by immunoblotting. Arterial leucine concentration and delivery to the leg increased in both groups and was significantly higher in LEU than in CTRL; however, transport into the muscle and intracellular availability did not differ between groups. MPS increased similarly in both groups 60 min postingestion. MPB decreased at 60 min only in LEU, but net muscle protein balance improved similarly. Components of mammalian target of rapamycin (mTOR) signaling were improved in LEU, but no changes were observed in ubiquitin-proteasome system signaling. Changes in light chain 3 and mTOR association with Unc-51-like kinase 1 indicate autophagy decreased more in LEU. We conclude that in 10 g of EAA, the leucine content typical of high quality proteins (~1.8 g) is sufficient to induce a maximal skeletal muscle protein anabolic response in young adults, but leucine may play a role in autophagy regulation. PMID:20844186

  2. Plasma arginine and leucine kinetics and urea production rates in burn patients.

    PubMed

    Yu, Y M; Young, V R; Castillo, L; Chapman, T E; Tompkins, R G; Ryan, C M; Burke, J F

    1995-05-01

    We measured plasma arginine and leucine kinetics and rates of urea production (appearance) in 12 severely burned patients (mean body surface burn area, 48%) during a basal state (low-dose intravenous glucose) and while receiving routine, total parenteral nutrition ([TPN] fed state) including an L-amino acid mixture, supplying a generous level of nitrogen (mean, 0.36 g N.kg-1.d-1). The two nutritional states were studied in random order using a primed 4-hour constant intravenous tracer infusion protocol. Stable-nuclide-labeled tracers were L-[guanidino-13C]arginine, L-[1-13C]leucine, [18O]urea, and NaH13CO3 (prime only), with blood and expired air samples drawn at intervals to determine isotopic abundance of arginine, citrulline, ornithine, alpha-ketoisocaproate ([KIC] for leucine), and urea in plasma and 13CO2 in breath. Results are compared with data obtained in these laboratories in healthy adults. Leucine kinetics (flux and disappearance into protein synthesis) indicated the expected higher turnover in burn patients than in healthy controls. Mean leucine oxidation rates are also higher and compared well with values predicted from urea production rates, provided that urea nitrogen recycling via intestinal hydrolysis is taken into account. The plasma urea flux was also higher than for normal subjects. Arginine fluxes as measured in the systemic whole body, via the plasma pool, were correspondingly higher in burned patients than in healthy controls and were in good agreement with values predicted from leucine-KIC kinetics. However, systemic whole-body arginine flux measured via the plasma pool was only 20% of the arginine flux estimated from the urea flux plus the rate of protein synthesis.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7752916

  3. Glucose and leucine kinetics in idiopathic ketotic hypoglycaemia

    PubMed Central

    Bodamer, O A; Hussein, K; Morris, A A; Langhans, C‐D; Rating, D; Mayatepek, E; Leonard, J V

    2006-01-01

    Aims To investigate glucose and leucine kinetics in association with metabolic and endocrine investigations in children with ketotic hypoglycaemia (KH) in order to elucidate the underlying pathophysiology. Methods Prospective interventional study using stable isotope tracer in nine children (mean age 4.23 years, range 0.9–9.8 years; seven males) with KH and 11 controls (mean age 4.57 years, range 0.16–12.3 years; four males). Results Plasma insulin levels were significantly lower in KH compared to subjects in the non‐KH group. Plasma ketone body levels were significantly higher in KH than in non‐KH. Basal metabolic rate was significantly higher in subjects with KH (45.48±7.41 v 31.81±6.72 kcal/kg/day) but the respiratory quotients were similar in both groups (KH v non‐KH, 0.84±0.05 v 0.8±0.04. Leucine oxidation rates were significantly lower in children with KH (12.25±6.25 v 31.96±8.59 μmol/kg/h). Hepatic glucose production rates were also significantly lower in KH (3.84±0.46 v 6.6±0.59 mg/kg/min). Conclusions KH is caused by a failure to sustain hepatic glucose production rather than by increased glucose oxidation rates. Energy demand is significantly increased, whereas leucine oxidation is reduced. PMID:16443613

  4. Responses of astrocytes in culture after low dose laser irradiation

    SciTech Connect

    Yew, D.T.; Zheng, D.R.; Au, C.; Li, W.W. )

    1990-03-01

    The effect of Helium-Neon low dose laser on astrocytes was investigated in cultures of isolated astrocytes from albino neonatal rats. The laser appeared to inhibit the growth of astrocytes as exemplified by the smaller sizes of the cells and the decreased leucine uptake in each cell after treatment. Temporary decrease in the number of mitoses was also observed, but this trend was reversed soon after. Electron microscopic studies revealed an increase in buddings from cell bodies and processes (branches) after irradiation.

  5. Protein Ingestion Induces Muscle Insulin Resistance Independent of Leucine-Mediated mTOR Activation

    PubMed Central

    Smith, Gordon I.; Yoshino, Jun; Stromsdorfer, Kelly L.; Klein, Seth J.; Magkos, Faidon; Reeds, Dominic N.; Klein, Samuel

    2015-01-01

    Increased plasma branched-chain amino acid concentrations are associated with insulin resistance, and intravenous amino acid infusion blunts insulin-mediated glucose disposal. We tested the hypothesis that protein ingestion impairs insulin-mediated glucose disposal by leucine-mediated mTOR signaling, which can inhibit AKT. We measured glucose disposal and muscle p-mTORSer2448, p-AKTSer473, and p-AKTThr308 in 22 women during a hyperinsulinemic-euglycemic clamp procedure with and without concomitant ingestion of whey protein (0.6 g/kg fat-free mass; n = 11) or leucine that matched the amount given with whey protein (n = 11). Both whey protein and leucine ingestion raised plasma leucine concentration by approximately twofold and muscle p-mTORSer2448 by ∼30% above the values observed in the control (no amino acid ingestion) studies; p-AKTSer473 and p-AKTThr308 were not affected by whey protein or leucine ingestion. Whey protein ingestion decreased insulin-mediated glucose disposal (median 38.8 [quartiles 30.8, 61.8] vs. 51.9 [41.0, 77.3] µmol glucose/µU insulin · mL−1 · min−1; P < 0.01), whereas ingestion of leucine did not (52.3 [43.3, 65.4] vs. 52.3 [43.9, 73.2]). These results indicate that 1) protein ingestion causes insulin resistance and could be an important regulator of postprandial glucose homeostasis and 2) the insulin-desensitizing effect of protein ingestion is not due to inhibition of AKT by leucine-mediated mTOR signaling. PMID:25475435

  6. Systemic exchangeability of enteral leucine: relationship to plasma flux

    SciTech Connect

    Istfan, N.W.; Ling, P.R.; Bistrian, B.R.; Blackburn, G.L.

    1988-04-01

    The exchangeability of enterally infused leucine within the systemic compartment was estimated in fasted and fed rats using L-(1-/sup 14/C)leucine as a tracer. The experimental design consisted of enteral and parenteral feedings with intravenous or intragastric tracer infusions. During continuous intragastric feeding, only 73 +/- 6% (SE) of the intragastric leucine tracer infusion was accounted for in the systemic circulation. When comparing intravenous vs. intragastric tracer, the estimate of the contribution of protein breakdown to plasma leucine flux was 6 +/- 1 (SE) mumol.h-1.100 g-1 and 18 +/- 3 (SE) mumol.h-1.100 g-1 (P less than 0.01), respectively, for the two routes of administration. Correction of enteral input (either isotope or total leucine), by a factor of 27% for first-pass extraction, eliminated all significant differences in plasma leucine kinetics. Of the 27% of enterally infused tracer not appearing systemically, only 3% could be accounted for in newly synthesized protein in the liver. The remainder is hypothesized to represent first-pass utilization of leucine in intestinal protein synthesis and other metabolic pathways in the splanchnic bed. In contrast, systemic appearance of enteral leucine was essentially complete in the fasted rats, indicating less splanchnic metabolism of leucine in this state. These data indicate that significant error can result in estimating the contribution of endogenous protein breakdown to plasma leucine flux during feeding if the systemic exchangeability of dietary leucine is not considered.

  7. Differentiating mucosal and hepatic metabolism of budesonide by local pretreatment with increasing doses of ketoconazole in the proximal jejunum.

    PubMed

    Seidegård, Janeric; Nyberg, Lars; Borgå, Olof

    2012-08-15

    Many drugs undergo first-pass metabolism both in the gut mucosa and the liver, but little is known about the relative efficiency of these two pathways. The objective of this study was to differentiate between mucosal and hepatic metabolism using budesonide as a probe. After a light breakfast, budesonide, 3mg, was infused locally in the proximal jejunum of eight healthy men on seven occasions, on six occasions after administering the CYP3A4 inhibitor ketoconazole 5 min before in the same jejunal position. The dose range of local inhibitor was 1-128 mg, the highest dose also preceded by an oral dose of 200mg given 12h earlier. Simultaneously with intrajejunal budesonide, deuterium-labelled budesonide (0.2mg) was administered intravenously. Pharmacokinetics of unlabelled and labelled budesonide in plasma was evaluated after LC-MS/MS analysis. Bioavailability of budesonide without inhibition was 27(12-42)%. All ketoconazole doses increased budesonide bioavailability. However, systemic clearance of labelled budesonide was unaffected by ketoconazole doses up to 16 mg but decreased significantly at doses of 64 mg and above. At the two highest doses (128 mg and above) bioavailability approached 100%, showing that budesonide was completely absorbed from jejunum. Ketoconazole doses up to 16 mg appeared to inhibit only mucosal enzymes, while higher doses inhibited also hepatic metabolism. Applying sigmoid E(max)-models of the mean inhibitions in mucosa and liver indicated that, in this study performed under fed conditions, their uninhibited extraction ratios of budesonide were approximately 0.32 and 0.60, respectively. Ketoconazole doses that inhibited half the metabolism were estimated at about 1mg in the mucosa and about 50mg in the liver. In conclusion, this study gave a rough estimate of the relation between mucosal and hepatic first-pass metabolism of budesonide. PMID:22538054

  8. Leucine metabolism in TNF-alpha- and endotoxin-treated rats: contribution of hepatic tissue.

    PubMed

    Holecek, M; Sprongl, L; Skopec, F; Andrýs, C; Pecka, M

    1997-12-01

    The effects of tumor necrosis factor-alpha (TNF-alpha; cachectin) and lipopolysaccharide of Salmonella enteritidis (LPS; endotoxin) on leucine metabolism in rats were evaluated in the whole body using intravenous infusion of L-[1-14C]leucine and in isolated perfused liver (IPL) using the single-pass perfusion technique with alpha-keto[1-14C]isocaproate as a tracer for measurement of ketoisocaproic acid (KIC) oxidation, and the recirculation technique for measurement of hepatic amino acid exchanges. The data obtained in TNF-alpha and LPS groups were compared with those obtained in controls. Both TNF-alpha and LPS treatment induced an increase of whole body leucine turnover, oxidation, and clearance. As the result of a higher increase of leucine oxidation than of incorporation into the pool of body proteins, the fractional oxidation of leucine was increased. The fractional rate of protein synthesis increased significantly in the spleen (both in TNF-alpha and LPS rats), in blood plasma, liver, colon, kidneys, gastrocnemius muscle (in LPS rats), and in lungs (TNF-alpha-treated rats), whereas it decreased in the jejunum (LPS rats). In IPL of TNF-alpha- and LPS-treated rats a decrease of KIC oxidation and higher uptake of branched-chain amino acids (BCAA; valine, leucine, and isoleucine) were observed when compared with control animals. We hypothesize that the negative consequences of increased whole body proteolysis and of increased oxidation of BCAA induced by TNF-alpha and/or LPS are reduced by decreased activity of hepatic branched-chain ketoacid dehydrogenase that can help resupply BCAA to the body. PMID:9435518

  9. Low doses of cocaine decrease, and high doses increase, anxiety-like behavior and brain progestogen levels among intact rats.

    PubMed

    Kohtz, Amy S; Paris, Jason J; Frye, Cheryl A

    2010-04-01

    There are sex and hormonal differences in response to cocaine that have been demonstrated in people and animal models. Cocaine can alter secretion of progestogens, such as progesterone (P), and its neuroactive metabolite, 5alpha-pregnan-3alpha-ol-20-one (3alpha,5alpha-THP). However, little research has been done on the neuroendocrine effects in the initiation phase of cocaine use. We hypothesize that some sex/hormonal differences in initiation phase responses to cocaine may be related to formation of progestogens. To investigate the role of progestogens in sex differences in response to acute cocaine, male and female rats in the high (proestrous) or low (diestrous) progestogen phase of the estrous cycle were administered cocaine (0, 5, 10, or 20mg/kg, IP). We examined cocaine's acute neuroendocrine effects on P and 3alpha,5alpha-THP levels, as well as its effects on acute psychomotor stimulation, anxiety, and sexual behaviors. Among rats that had P and/or 3alpha,5alpha-THP levels increased in response to cocaine, enhanced acute psychomotor stimulation was observed. Results suggest that cocaine produces U-shaped curves for progestogens, and anxiety-like behaviors. Male rats were less susceptible to these effects of cocaine than were proestrous or diestrous female rats. However, cocaine's disruption of sexual behaviors was similar among males and proestrous females. These data suggest a complex interaction between hormonal milieu and the neuroendocrine and behavioral effects of cocaine. PMID:20171966

  10. Dose-dependent consumption of farmed Atlantic salmon (salmo salar) increases plasma phospholipid n-3 fatty acids differentially

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ABSTRACT Background: Enhanced n-3 intake benefit CVD risk reduction. Increasing consumption at a population level will be better addressed by dietary modification than through supplementation. However, limited data are available on the effect of increasing doses of fish intake on circulating level...

  11. Kinetics of sequential metabolism from D-leucine to L-leucine via alpha-ketoisocaproic acid in rat.

    PubMed

    Hasegawa, Hiroshi; Matsukawa, Takehisa; Shinohara, Yoshihiko; Hashimoto, Takao

    2002-12-01

    D-Leucine is considered to be converted into the L-enantiomer by two steps: oxidative deamination to form alpha-ketoisocaproic acid (KIC) and subsequent stereospecific reamination of KIC. We investigated the pharmacokinetics of leucine enantiomers and KIC in rats to evaluate how deamination of D-leucine, reamination of KIC, and decarboxylation of KIC were affected to the overall extent that converted D-leucine into the L-enantiomer. After intravenous administrations of D-[(2)H(7)]leucine, L-[(2)H(7)]leucine, or [(2)H(7)]KIC, their plasma concentrations together with endogenous L-leucine and KIC were determined by gas chromatography-mass spectrometry. The rapid appearances of [(2)H(7)]KIC and L-[(2)H(7)]leucine were observed after administration of D-[(2)H(7)]leucine, whereas no detectable amount of D-[(2)H(7)]leucine was found after administrations of [(2)H(7)]KIC or L-[(2)H(7)]leucine. The fraction of conversion from D-[(2)H(7)]leucine into [(2)H(7)]KIC (F(D-->KIC)) was estimated by using the area under the curve (AUC) of [(2)H(7)]KIC on the D-[(2)H(7)]leucine administration [AUC(KIC(D))] and that of [(2)H(7)]KIC on the [(2)H(7)]KIC administration (AUC(KIC)) to yield 70.1%. The fraction of conversion from [(2)H(7)]KIC to L-[(2)H(7)]leucine (F(KIC-->L)) was 40.2%. The fraction of conversion from D-leucine to the L-enantiomer (F(D-->L)) was considered to be the product of F(D-->KIC) and F(KIC-->L), indicating that 28.2% of D-[(2)H(7)]leucine was metabolized to L-[(2)H(7)]leucine via [(2)H(7)]KIC. These results suggested that the relatively low conversion of D-leucine into the L-enantiomer might depend on irreversible decarboxylation of KIC. Regardless of [(2)H(7)]KIC, F(D-->L) was also calculated directly using AUC(L(D)) and AUC(L) to yield 27.5%. There were no differences between the two F(D-->L) values, suggesting that almost all of the formation of L-[(2)H(7)]leucine from D-[(2)H(7)]leucine occurred via [(2)H(7)]KIC as an intermediate. PMID:12433816

  12. Increased Computed Tomography Dose Due to Miscentering With Use of Automated Tube Voltage Selection: Phantom and Patient Study.

    PubMed

    Filev, Peter D; Mittal, Pardeep K; Tang, Xiangyang; Duong, Phuong-Anh; Wang, Xiaojing; Small, William C; Applegate, Kimberly; Moreno, Courtney C

    2016-01-01

    The purpose of the article is to determine if miscentering affected dose with use of automated tube voltage selection software. An anthropomorphic phantom was imaged at different table heights (centered in the computed tomography [CT] gantry, and -6, -3, +3, and +5.7cm relative to the centered position). Topogram magnification, tube voltage selection, and dose were assessed. Effect of table height on dose also was assessed retrospectively in human subjects (n = 50). When the CT table was positioned closer to the x-ray source, subjects appeared up to 33% magnified in topogram images. When subjects appeared magnified in topogram images, automated software selected higher tube potentials and tube currents that were based on the magnified size of the subject rather than the subject׳s true size. Table height strongly correlated with CT dose index (r = 0.98, P < 0.05) and dose length product (r = 0.98, P < 0.05) in the phantom study. Transverse dimension in the topogram highly correlated with dose in human subjects (r = 0.75-0.87, P <0.05). Miscentering results in increased dose due to topogram magnification with automated voltage selection software. PMID:26810714

  13. Age Attenuates Leucine Oxidation after Eccentric Exercise

    PubMed Central

    Kullman, E. L.; Campbell, W. W.; Krishnan, R. K.; Yarasheski, K. E.; Evans, W. J.; Kirwan, J. P.

    2013-01-01

    Aging may alter protein metabolism during periods of metabolic and physiologic challenge. The purpose of this study was to assess the effects of age on whole-body amino acid turnover in response to eccentric exercise and hyperglycemia-induced hyperinsulinemia. 16 healthy men were divided into young (N = 8) and older (N = 8) groups. Protein metabolism was assessed using a [1-13C]-leucine isotopic tracer approach. Measures were obtained under fasted basal conditions and during 3-h hyperglycemic clamps that were performed without (control) and 48 h after eccentric exercise. Exercise reduced leucine oxidation in the younger men (P < 0.05), but not in older men. Insulin sensitivity was inversely correlated with leucine oxidation (P < 0.05), and was lower in older men (P < 0.05). Healthy aging is associated with an impaired capacity to adjust protein oxidation in response to eccentric exercise. The decreased efficiency of protein utilization in older men may contribute to impaired maintenance, growth, and repair of body tissues with advancing age. PMID:23325713

  14. Differential regulation of protein synthesis in skeletal muscle and liver of neonatal pigs by leucine through an mTORC1-dependent pathway.

    PubMed

    Suryawan, Agus; Nguyen, Hanh V; Almonaci, Rosemarie D; Davis, Teresa A

    2012-02-28

    Neonatal growth is characterized by a high protein synthesis rate that is largely due to an enhanced sensitivity to the postprandial rise in insulin and amino acids, especially leucine. The mechanism of leucine's action in vivo is not well understood. In this study, we investigated the effect of leucine infusion on protein synthesis in skeletal muscle and liver of neonatal pigs. To evaluate the mode of action of leucine, we used rapamycin, an inhibitor of mammalian target of rapamycin (mTOR) complex-1 (mTORC1). Overnight-fasted 7-day-old piglets were treated with rapamycin for 1 hour and then infused with leucine (400 μmol·kg(-1)·h(-1)) for 1 hour. Leucine infusion increased the rate of protein synthesis, and ribosomal protein S6 kinase 1 (S6K1) and eukaryotic initiation factor (eIF) 4E-binding protein-1 (4E-BP1) phosphorylation in gastrocnemius and masseter muscles (P < 0.05), but not in the liver. The leucine-induced stimulation of protein synthesis and S6K1 and 4E-BP1 phosphorylation were completely blocked by rapamycin, suggesting that leucine action is by an mTORC1-dependent mechanism. Neither leucine nor rapamycin had any effect on the activation of the upstream mTORC1 regulators, AMP-activated protein kinase and protein kinase B, in skeletal muscle or liver. The activation of eIF2α and elongation factor 2 was not affected by leucine or rapamycin, indicating that these two pathways are not limiting steps of leucine-induced protein synthesis. These results suggest that leucine stimulates muscle protein synthesis in neonatal pigs by inducing the activation of mTORC1 and its downstream pathway leading to mRNA translation. PMID:22675606

  15. Dose-Dependent Changes in Influenza Virus-Infected Dendritic Cells Result in Increased Allogeneic T-Cell Proliferation at Low, but Not High, Doses of Virus

    PubMed Central

    Oh, SangKon; McCaffery, J. Michael; Eichelberger, Maryna C.

    2000-01-01

    During the acute phase of infection with influenza A virus, the degree of lymphopenia correlates with severity of disease. Factors that contribute to T-cell activation during influenza virus infection may contribute to this observation. Since the immune response is initiated when dendritic cells (DC) interact with T cells, we have established an in vitro system to examine the effects of influenza virus infection on DC function. Our results show that allogeneic T-cell proliferation was dependent on the dose of A/PR/8/34 used to infect DC, with enhanced responses at low, but not high, multiplicities of infection. The lack of enhancement at high virus doses was not primarily due to the increased rate of DC apoptosis, but required viral replication and neuraminidase (NA) activity. Clusters that formed between DC or between DC and T cells were also dependent on the viral dose. This change in cellular interaction may oppose T-cell proliferation in response to DC infected with high doses of PR8, since the increased contact between DC resulted in the exclusion of T cells. The enhanced alloreactive T-cell response was restored by neutralization of transforming growth factor β1 (TGF-β1). It is likely that NA present on viral particles released from DC infected with high doses of PR8 activates TGF-β1. Future studies will determine the mechanism by which TGF-β1 modifies the in vitro T-cell response and address the contribution of this cytokine to the lymphopenia observed in severe disease. PMID:10823850

  16. High Dose Atorvastatin Associated with Increased Risk of Significant Hepatotoxicity in Comparison to Simvastatin in UK GPRD Cohort

    PubMed Central

    Clarke, Alan T.; Johnson, Paul C. D.; Hall, Gillian C.; Ford, Ian; Mills, Peter R.

    2016-01-01

    Background & Aims Occasional risk of serious liver dysfunction and autoimmune hepatitis during atorvastatin therapy has been reported. We compared the risk of hepatotoxicity in atorvastatin relative to simvastatin treatment. Methods The UK GPRD identified patients with a first prescription for simvastatin [164,407] or atorvastatin [76,411] between 1997 and 2006, but with no prior record of liver disease, alcohol-related diagnosis, or liver dysfunction. Incident liver dysfunction in the following six months was identified by biochemical value and compared between statin groups by Cox regression model adjusting for age, sex, year treatment started, dose, alcohol consumption, smoking, body mass index and comorbid conditions. Results Moderate to severe hepatotoxicity [bilirubin >60μmol/L, AST or ALT >200U/L or alkaline phosphatase >1200U/L] developed in 71 patients on atorvastatin versus 101 on simvastatin. Adjusted hazard ratio [AHR] for all atorvastatin relative to simvastatin was 1.9 [95% confidence interval 1.4–2.6]. High dose was classified as 40–80mg daily and low dose 10–20mg daily. Hepatotoxicity occurred in 0.44% of 4075 patients on high dose atorvastatin [HDA], 0.07% of 72,336 on low dose atorvastatin [LDA], 0.09% of 44,675 on high dose simvastatin [HDS] and 0.05% of 119,732 on low dose simvastatin [LDS]. AHRs compared to LDS were 7.3 [4.2–12.7] for HDA, 1.4 [0.9–2.0] for LDA and 1.5 [1.0–2.2] for HDS. Conclusions The risk of hepatotoxicity was increased in the first six months of atorvastatin compared to simvastatin treatment, with the greatest difference between high dose atorvastatin and low dose simvastatin. The numbers of events in the analyses were small. PMID:26983033

  17. Strontium increases vertebral bone volume in rats at a low dose that does not induce detectable mineralization defect.

    PubMed

    Grynpas, M D; Hamilton, E; Cheung, R; Tsouderos, Y; Deloffre, P; Hott, M; Marie, P J

    1996-03-01

    Low doses of strontium and fluoride were shown to increase bone formation and trabecular bone density in rodents. To assess whether strontium or fluoride affect the quality of the mineral at doses known to increase bone density, we have determined the effects of low doses of strontium and fluoride on bone formation and bone mineral characteristics in rats. Adult rats were given strontium alone (0.20%), fluoride alone (1 mg/kg per day), or the combined treatment for 8 weeks. Strontium levels in serum and femur were similar in groups treated with strontium alone or in combination, being about 5% of calcium levels. Biochemical and neutron activation analyses in femur showed that calcium and magnesium contents did not differ in the four group of rats, suggesting that strontium was incorporated in the apatite lattice of the bone minerals in the strontium-treated rats. The mineralized bone volume was significantly increased by 17% in the strontium-treated group, by 20% in the fluoride-treated group, and by 19% in rats given with the combined treatment. This was associated with increased osteoid surface, osteoblast surface, and double tetracycline labeled surfaces in the strontium-treated and fluoride-treated groups, showing that the number of bone forming sites was increased. However, the mineral apposition rate, the osteoid thickness, and the mineralization lag time were similar in controls and treated groups, reflecting the lack of deleterious effects of low doses of strontium and fluoride on bone mineralization. The density fractionation analysis measured in the femur also showed that neither strontium, nor fluoride at the low doses used, significantly altered the mineralization profile. The results indicate that treatment with low doses of strontium or fluoride increase the number of bone forming sites and vertebral bone volume in rats, but does not have detectable adverse effects on the mineral profile, bone mineral chemistry or bone matrix mineralization. PMID

  18. Leucine Loading Test is Only Discriminative for 3-Methylglutaconic Aciduria Due to AUH Defect.

    PubMed

    Wortmann, Saskia B; Kluijtmans, Leo A J; Sequeira, Silvia; Wevers, Ron A; Morava, Eva

    2014-01-01

    Currently, six inborn errors of metabolism with 3-methylglutaconic aciduria as discriminative feature are known. The "Primary 3-methylglutaconic aciduria," 3-methylglutaconyl-CoA hydratase deficiency or AUH defect, is a disorder of leucine catabolism. For all other subtypes, also denoted "Secondary 3-methylglutaconic acidurias" (TAZ defect or Barth syndrome, SERAC1 defect or MEGDEL syndrome, OPA3 defect or Costeff syndrome, DNAJC19 defect or DCMA syndrome, TMEM70 defect, "not otherwise specified (NOS) 3-MGA-uria"), the origin of 3-methylglutaconic aciduria remains enigmatic but is hypothesized to be independent from leucine catabolism. Here we show the results of leucine loading test in 21 patients with different inborn errors of metabolism who present with 3-methylglutaconic aciduria. After leucine loading urinary 3-methylglutaconic acid levels increased only in the patients with an AUH defect. This strongly supports the hypothesis that 3-methylglutaconic aciduria is independent from leucine breakdown in other inborn errors of metabolism with 3-methylglutaconic aciduria and also provides a simple test to discriminate between primary and secondary 3-methylglutaconic aciduria in regular patient care. PMID:24757000

  19. Functional Profiling Discovers the Dieldrin Organochlorinated Pesticide Affects Leucine Availability in Yeast

    PubMed Central

    Vulpe, Chris D.

    2013-01-01

    Exposure to organochlorinated pesticides such as dieldrin has been linked to Parkinson’s and Alzheimer’s diseases, endocrine disruption, and cancer, but the cellular and molecular mechanisms of toxicity behind these effects remain largely unknown. Here we demonstrate, using a functional genomics approach in the model eukaryote Saccharomyces cerevisiae, that dieldrin alters leucine availability. This model is supported by multiple lines of congruent evidence: (1) mutants defective in amino acid signaling or transport are sensitive to dieldrin, which is reversed by the addition of exogenous leucine; (2) dieldrin sensitivity of wild-type or mutant strains is dependent upon leucine concentration in the media; (3) overexpression of proteins that increase intracellular leucine confer resistance to dieldrin; (4) leucine uptake is inhibited in the presence of dieldrin; and (5) dieldrin induces the amino acid starvation response. Additionally, we demonstrate that appropriate negative regulation of the Ras/protein kinase A pathway, along with an intact pyruvate dehydrogenase complex, is required for dieldrin tolerance. Many yeast genes described in this study have human orthologs that may modulate dieldrin toxicity in humans. PMID:23358190

  20. Effect of strength training session on plasma amino acid concentration following oral ingestion of leucine, BCAAs or glutamine in men.

    PubMed

    Mero, Antti; Leikas, Anne; Knuutinen, Juha; Hulmi, Juha J; Kovanen, Vuokko

    2009-01-01

    We examined the acute effects of a 1-h strength training session (STS) on plasma amino acid concentration following orally ingestion of leucine, branched-chain amino acids (BCAAs) or glutamine in nine physically active men who participated in double-blinded and randomised experiments. The subjects took placebo, leucine, BCAAs, or glutamine capsules (50 mg/kg) in either rest (REST) or STS condition. Blood samples were taken before and at 30, 60, 90, and 120 min after the beginning of the treatment and they were assayed for plasma amino acids with HPLC. Following both leucine and BCAA ingestion the peak concentration of leucine was similar at rest (524 +/- 46 and 530 +/- 29 nmol/ml, respectively) and similar after STS (398 +/- 43 and 387 +/- 46 nmol/ml, respectively) but the rest and STS concentrations differed from each other (P < 0.01-0.001). The modelled polynomial data for the leucine treatment showed that the peak concentration of leucine occurred at 67 min at rest and at 90 min in STS (difference between REST and STS: P = 0.012). For the BCAA treatment the polynomial data showed that the peak concentration of leucine occurred at 72 min at rest and at 78 min in STS (P = 0.067). The peak concentration of glutamine was similar in both rest and STS condition and occurred at 60 min at rest and at 57 min in STS. In conclusion, 1-h of STS slows the increase in the peak concentration of plasma leucine similarly after oral ingestion of leucine or BCAAs but after oral ingestion of glutamine it has no slowing effect on glutamine concentration. PMID:19015870

  1. The time variation of dose rate artificially increased by the Fukushima nuclear crisis

    PubMed Central

    Hosoda, Masahiro; Tokonami, Shinji; Sorimachi, Atsuyuki; Monzen, Satoru; Osanai, Minoru; Yamada, Masatoshi; Kashiwakura, Ikuo; Akiba, Suminori

    2011-01-01

    A car-borne survey for dose rate in air was carried out in March and April 2011 along an expressway passing northwest of the Fukushima Dai-ichi Nuclear Power Station which released radionuclides starting after the Great East Japan Earthquake on March 11, 2011, and in an area closer to the Fukushima NPS which is known to have been strongly affected. Dose rates along the expressway, i.e. relatively far from the power station were higher after than before March 11, in some places by several orders of magnitude, implying that there were some additional releases from Fukushima NPS. The maximum dose rate in air within the high level contamination area was 36 μGy h−1, and the estimated maximum cumulative external dose for evacuees who came from Namie Town to evacuation sites (e.g. Fukushima, Koriyama and Nihonmatsu Cities) was 68 mSv. The evacuation is justified from the viewpoint of radiation protection. PMID:22355606

  2. Increased Subventricular Zone Radiation Dose Correlates With Survival in Glioblastoma Patients After Gross Total Resection

    SciTech Connect

    Chen, Linda; Guerrero-Cazares, Hugo; Ye, Xiaobu; Ford, Eric; McNutt, Todd; Kleinberg, Lawrence; Lim, Michael; Chaichana, Kaisorn; Quinones-Hinojosa, Alfredo; Redmond, Kristin

    2013-07-15

    Purpose: Neural progenitor cells in the subventricular zone (SVZ) have a controversial role in glioblastoma multiforme (GBM) as potential tumor-initiating cells. The purpose of this study was to examine the relationship between radiation dose to the SVZ and survival in GBM patients. Methods and Materials: The study included 116 patients with primary GBM treated at the Johns Hopkins Hospital between 2006 and 2009. All patients underwent surgical resection followed by adjuvant radiation therapy with intensity modulated radiation therapy (60 Gy/30 fractions) and concomitant temozolomide. Ipsilateral, contralateral, and bilateral SVZs were contoured on treatment plans by use of coregistered magnetic resonance imaging and computed tomography. Multivariate Cox regression was used to examine the relationship between mean SVZ dose and progression-free survival (PFS), as well as overall survival (OS). Age, Karnofsky Performance Status score, and extent of resection were used as covariates. The median age was 58 years (range, 29-80 years). Results: Of the patients, 12% underwent biopsy, 53% had subtotal resection (STR), and 35% had gross total resection (GTR). The Karnofsky Performance Status score was less than 90 in 54 patients and was 90 or greater in 62 patients. The median ipsilateral, contralateral, and bilateral mean SVZ doses were 48.7 Gy, 34.4 Gy, and 41.5 Gy, respectively. Among patients who underwent GTR, a mean ipsilateral SVZ dose of 40 Gy or greater was associated with a significantly improved PFS compared with patients who received less than 40 Gy (15.1 months vs 10.3 months; P=.028; hazard ratio, 0.385 [95% confidence interval, 0.165-0.901]) but not in patients undergoing STR or biopsy. The subgroup of GTR patients who received an ipsilateral dose of 40 Gy or greater also had a significantly improved OS (17.5 months vs 15.6 months; P=.027; hazard ratio, 0.385 [95% confidence interval, 0.165-0.895]). No association was found between SVZ radiation dose and PFS

  3. Increasing dose gradient and uniformity in small fields using modulation: Theory and prototypes for cone-based stereotactic radiosurgery

    SciTech Connect

    Bender, Edward T.

    2014-05-15

    Purpose: To investigate the theoretical limits to the tradeoff between dose gradient and uniformity when modulation is used in the context of cone based SRS, and to design a prototype collimation device that allows for steeper dose gradients and/or higher target uniformity as compared to a standard circular collimator. Methods: An inverse planning optimization is performed in the context of idealized phantom geometry to determine the ideal fluence pattern that best approximates a “rect function” dose distribution. Ideal fluence patterns were approximated in a prototype device and radiochromic film dosimetry was utilized to compare the prototype device to a standard circular collimator. Results: For choices of prescription isodose lines above approximately 50%, utilizing modulation allows for an improved tradeoff between dose gradient index and dose heterogeneity index. Compensators placed within the circular collimator can achieve the necessary modulation. Conclusions: Using modulation with features on a submillimeter distance scale, it is possible to increase the dose gradient and/or uniformity in small fields.

  4. Incorporation of fucose and leucine into PNS myelin proteins in nerves undergoing early Wallerian degeneration

    SciTech Connect

    Peterson, R.G.; Baughman, S.; Scheidler, D.M.

    1981-02-01

    The simultaneous incorporation of (/sup 3/H)fucose and (1-/sup 14/C)leucine into normal rat sciatic nerve was examined using an in vitro incubation model. A linear rate of protein precursor uptake was found in purified myelin protein over 1/2-6 hr of incubation utilizing a supplemented medium containing amino acids. This model was then used to examine myelin protein synthesis in nerves undergoing degeneration at 1-4 days following a crush injury. Data showed a statistically significant decrease in the ratio of fucose to leucine at 2, 3, and 4 days of degeneration, which was the consequence of a significant increase in leucine uptake. These results, plus substantial protein recovery in axotomized nerves, are indicative of active synthesis of proteins that purify with myelin during early Wallerian degeneration.

  5. Dose escalation in brachytherapy for cervical cancer: impact on (or increased need for) MRI-guided plan optimisation

    PubMed Central

    Paton, A M; Chalmers, K E; Coomber, H; Cameron, A L

    2012-01-01

    Objective The aim of this study was to assess the impact of dose escalation on the proportion of patients requiring MR image-guided optimisation rather than standard Manchester-based CT-guided planning, and the level of escalation achievable. Methods 30 patients with cervical cancer treated with external beam radiotherapy and image-guided brachytherapy (IGBT) had MR images acquired at the first fraction of IGBT. Gross tumour volume and high-risk clinical target volume (HR CTV) were contoured and treatment plans retrospectively produced for a range of total 2-Gy equivalent (EQD2) prescription doses from 66 Gyα/β=10 to 90 Gyα/β=10 (HR CTV D90). Standard Manchester system-style plans were produced, prescribed to point A and then optimised where necessary with the aim of delivering at least the prescription dose to the HR CTV D90 while respecting organ-at-risk (OAR) tolerances. Results Increasing the total EQD2 from 66 Gyα/β=10 to 90 Gyα/β=10 increased the number of plans requiring optimisation from 13.3% to 90%. After optimisation, the number of plans achieving the prescription dose ranged from 93.3% (66 Gyα/β=10) to 63.3% (90 Gyα/β=10) with the mean±standard deviation for HR CTV D90 EQD2 from 78.4±12.4 Gyα/β=10 (66 Gyα/β=10) to 94.1±19.9 Gyα/β=10 (90 Gyα/β=10). Conclusion As doses are escalated, the need for non-standard optimised planning increases, while benefits in terms of increased target doses actually achieved diminish. The maximum achievable target dose is ultimately limited by proximity of OARs. Advances in knowledge This work represents a guide for other centres in determining the highest practicable prescription doses while considering patient throughput and maintaining acceptable OAR doses. PMID:23175490

  6. Hypertrophy-Promoting Effects of Leucine Supplementation and Moderate Intensity Aerobic Exercise in Pre-Senescent Mice

    PubMed Central

    Xia, Zhi; Cholewa, Jason; Zhao, Yan; Yang, Yue-Qin; Shang, Hua-Yu; Guimarães-Ferreira, Lucas; Naimo, Marshall Alan; Su, Quan-Sheng; Zanchi, Nelo Eidy

    2016-01-01

    Several studies have indicated a positive influence of leucine supplementation and aerobic training on the aging skeletal muscle signaling pathways that control muscle protein balance and muscle remodeling. However, the effect of a combined intervention requires further clarification. Thirteen month old CD-1® mice were subjected to moderate aerobic exercise (45 min swimming per day with 3% body weight workload) and fed a chow diet with 5% leucine or 3.4% alanine for 8 weeks. Serum and plasma were prepared for glucose, urea nitrogen, insulin and amino acid profile analysis. The white gastrocnemius muscles were used for determination of muscle size and signaling proteins involved in protein synthesis and degradation. The results show that both 8 weeks of leucine supplementation and aerobic training elevated the activity of mTOR (mammalian target of rapamycin) and its downstream target p70S6K and 4E-BP1, inhibited the ubiquitin-proteasome system, and increased fiber cross-sectional area (CSA) in white gastrocnemius muscle. Moreover, leucine supplementation in combination with exercise demonstrated more significant effects, such as greater CSA, protein content and altered phosphorylation (suggestive of increased activity) of protein synthesis signaling proteins, in addition to lower expression of proteins involved in protein degradation compared to leucine or exercise alone. The current study shows moderate aerobic training combined with 5% leucine supplementation has the potential to increase muscle size in fast-twitch skeletal muscle during aging, potentially through increased protein synthesis and decreased protein breakdown. PMID:27144582

  7. Hypertrophy-Promoting Effects of Leucine Supplementation and Moderate Intensity Aerobic Exercise in Pre-Senescent Mice.

    PubMed

    Xia, Zhi; Cholewa, Jason; Zhao, Yan; Yang, Yue-Qin; Shang, Hua-Yu; Guimarães-Ferreira, Lucas; Naimo, Marshall Alan; Su, Quan-Sheng; Zanchi, Nelo Eidy

    2016-01-01

    Several studies have indicated a positive influence of leucine supplementation and aerobic training on the aging skeletal muscle signaling pathways that control muscle protein balance and muscle remodeling. However, the effect of a combined intervention requires further clarification. Thirteen month old CD-1(®) mice were subjected to moderate aerobic exercise (45 min swimming per day with 3% body weight workload) and fed a chow diet with 5% leucine or 3.4% alanine for 8 weeks. Serum and plasma were prepared for glucose, urea nitrogen, insulin and amino acid profile analysis. The white gastrocnemius muscles were used for determination of muscle size and signaling proteins involved in protein synthesis and degradation. The results show that both 8 weeks of leucine supplementation and aerobic training elevated the activity of mTOR (mammalian target of rapamycin) and its downstream target p70S6K and 4E-BP1, inhibited the ubiquitin-proteasome system, and increased fiber cross-sectional area (CSA) in white gastrocnemius muscle. Moreover, leucine supplementation in combination with exercise demonstrated more significant effects, such as greater CSA, protein content and altered phosphorylation (suggestive of increased activity) of protein synthesis signaling proteins, in addition to lower expression of proteins involved in protein degradation compared to leucine or exercise alone. The current study shows moderate aerobic training combined with 5% leucine supplementation has the potential to increase muscle size in fast-twitch skeletal muscle during aging, potentially through increased protein synthesis and decreased protein breakdown. PMID:27144582

  8. Double-Blind, Randomized Trial of Alternative Letrozole Dosing Regimens in Postmenopausal Women with Increased Breast Cancer Risk.

    PubMed

    López, Ana Maria; Pruthi, Sandhya; Boughey, Judy C; Perloff, Marjorie; Hsu, Chiu-Hsieh; Lang, Julie E; Ley, Michele; Frank, Denise; Taverna, Josephine A; Chow, H-H Sherry

    2016-02-01

    Aromatase inhibitors (AI) profoundly suppress estrogen levels in postmenopausal women and are effective in breast cancer prevention among high-risk postmenopausal women. Unfortunately, AI treatment is associated with undesirable side effects that limit patient acceptance for primary prevention of breast cancer. A double-blind, randomized trial was conducted to determine whether low and intermittent doses of letrozole can achieve effective estrogen suppression with a more favorable side-effect profile. Overall, 112 postmenopausal women at increased risk for breast cancer were randomized to receive letrozole at 2.5 mg once daily (QD, standard dose arm), 2.5 mg every Monday, Wednesday, and Friday (Q-MWF), 1.0 mg Q-MWF, or 0.25 mg Q-MWF for 24 weeks. Primary endpoint was suppression in serum estradiol levels at the end of letrozole intervention. Secondary endpoints included changes in serum estrone, testosterone, C-telopeptide (marker of bone resorption), lipid profile, and quality-of-life measures (QoL) following treatment. Significant estrogen suppression was observed in all dose arms with an average of 75% to 78% and 86% to 93% reduction in serum estradiol and estrone levels, respectively. There were no differences among dose arms with respect to changes in C-telopeptide levels, lipid profile, adverse events (AE), or QoL measures. We conclude that low and intermittent doses of letrozole are not inferior to standard dose in estrogen suppression and resulted in a similar side-effect profile compared with standard dose. Further studies are needed to determine the feasibility of selecting an effective AI dosing schedule with better tolerability. Cancer Prev Res; 9(2); 142-8. ©2015 AACR. PMID:26667449

  9. Increased level/dose ratio of amphotericin-B in premature infants with renal failure.

    PubMed

    Higuchi, R; Kusumoto, S; Ban, H; Iwahashi, S; Kobayashi, M; Sumiyama, K; Koike, M

    1993-06-01

    We introduced continuous intravenous infusion of amphotericin-B (AMPH-B) to extremely low birthweight (ELBW) infants (< 1000 g) with or without renal failure as a single agent for treating definite or probable systemic candidiasis. The species of Candida isolated from blood or tracheal aspirate or urine were C. albicans in seven infants, C glabrata in two, C. tropicalis in one and C. parapsilosis in one. The minimal inhibitory concentrations (MIC) of AMPH-B required against these isolates were less than 0.2 micrograms/mL except for that against one strain of C. albicans (0.78 microgram/mL). Serum AMPH-B levels were 0.31-0.78 (0.51 +/- 0.14) micrograms/mL when doses of 0.2-0.55 (0.32 +/- 0.11) mg/kg per day were being administered. The serum level was higher than the MIC of each isolate in all but one infant who died of disseminated intravascular coagulation and Candida pneumonia. Another infant died of congenital heart disease. The other nine infants survived. The serum level showed no correlation with the daily dose. The ratio of the serum level to the daily dose (L/D ratio) showed a significant correlation to serum creatinine (r = 0.787) and the linear regression curve followed the equation: L/D ratio = 0.223 x serum creatinine + 1.11 (P < 0.01). Few adverse effects due to AMPH-B were noted. Our data may give a simple reference to serum AMPH-B levels during continuous intravenous infusion from the dose and the serum creatinine level. PMID:8351992

  10. Efavirenz and rifampicin in the South African context: is there a need to dose increase efavirenz with concurrent rifampicin therapy?

    PubMed Central

    Orrell, Catherine; Cohen, Karen; Conradie, Francesca; Zeinecker, Jennifer; Ive, Prudence; Sanne, Ian; Wood, Robin

    2011-01-01

    Introduction Increasing EFV dose from 600mg to 800mg daily has been suggested with concomitant RFN, as induction of cytochrome p450 isoenzymes may reduce EFV plasma concentrations Methods Individuals from the CIPRA-South Africa cohort taking EFV-based ART with concomitant TB were dosed with either increased-(800mg) or standard-(600mg) dose EFV during TB treatment. After TB therapy all took 600mg EFV. Two mid-dosing interval EFV concentrations were determined from each individual: after 4 weeks of concomitant EFV and RFN therapy, and at least 4 weeks after TB therapy completion. Mid-dosing interval EFV concentrations were compared within individuals using the Wilcoxon signed rank test. Results Paired-samples were collected from 72 individuals. 45(63%) were women; median weight 59kg (IQR52-67kg). At ART start median CD4 count was114 cells/mm3 (IQR37-165), median viral load 5.5log (IQR5.1–5.9). 38 (53%) took 800mg EFV during TB treatment and 34(47%) took 600mg. EFV concentrations in the 800mg group were higher with RFN [[2.9mg/L (IQR 1.8–5.6)] than without [2.1mg/L (IQR 1.4–3.0)

  11. Pathway for isoleucine formation form pyruvate by leucine biosynthetic enzymes in leucine-accumulating isoleucine revertants of Serratia marcescens.

    PubMed

    Kisumi, M; Komatsubara, S; Chibata, I

    1977-07-01

    Leaky revertants isolated from isoleucine auxotrophs of Serratia marcescens mutant resistant to alpha-aminobutyric acid were previously reported to accumulate leucine in the medium, due to the absence of both feedback inhibition and repression of leucine biosynthesis. Growth of the revertant was accelerated by pyruvate, D(-)-citramalate, citraconate, and alpha-ketobutyrate, but not by threonine. Extracts of the revertant exhibited high activities of pyruvate-dependent coenzyme A liberation from acetyl-coenzyme A, hydration of citraconate, and conversion of citraconate to alpha-ketobutyrate, but showed no threonine-deaminating activity. In the leucine-accumulating revertants the above three activities were not affected by leucine, but in the wild strain and other revertants accumulating no leucine all or one of these activities was controlled by leucine. A leucine auxotroph isolated from the leucine-accumulating revertant showed isoleucine auxotrophy as well. From these data, it is concluded that, in leucine-accumulating revertants, of S. marcescent, isoleucine, is synthesized from alpha-ketobutyrate via citramalate formed from pyruvate annd acetyl-coenzyme A by leucine biosynthetic enzymes, as a result of desensitization of alpha-isopropylmalate synthetase to feedback inhibition. PMID:142769

  12. Efficacy of increasing the therapeutic index of irinotecan, plasma and tissue selenium concentrations is methylselenocysteine dose dependent

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to understand the basis for the efficacy of methylselenocysteine (MSC) in increasing the therapeutic index of irinotecan against human tumore xenografts. Nude mice bearing human FaDu and A253 tumors were treated orally with different doses of MSC and irinotecan. Plasma, tum...

  13. L-leucine transport in human breast cancer cells (MCF-7 and MDA-MB-231): kinetics, regulation by estrogen and molecular identity of the transporter.

    PubMed

    Shennan, D B; Thomson, J; Gow, I F; Travers, M T; Barber, M C

    2004-08-30

    The transport of L-leucine by two human breast cancer cell lines has been examined. L-leucine uptake by MDA-MB-231 and MCF-7 cells was via a BCH-sensitive, Na+ -independent pathway. L-leucine uptake by both cell lines was inhibited by L-alanine, D-leucine and to a lesser extent by L-lysine but not by L-proline. Estrogen (17beta-estradiol) stimulated L-leucine uptake by MCF-7 but not by MDA-MB-231 cells. L-leucine efflux from MDA-MB-231 and MCF-7 cells was trans-stimulated by BCH in a dose-dependent fashion. The effect of external BCH on L-leucine efflux from both cell types was almost abolished by reducing the temperature from 37 to 4 degrees C. There was, however, a significant efflux of L-leucine under zero-trans conditions which was also temperature-sensitive. L-glutamine, L-leucine, D-leucine, L-alanine, AIB and L-lysine all trans-stimulated L-leucine release from MDA-MB-231 and MCF-7 cells. In contrast, D-alanine and L-proline had little or no effect. The anti-cancer agent melphalan inhibited L-leucine uptake by MDA-MB-231 cells but had no effect on L-leucine efflux. Quantitative real-time PCR revealed that LAT1 mRNA was approximately 200 times more abundant than LAT2 mRNA in MCF-7 cells and confirmed that MDA-MB-231 cells express LAT1 but not LAT2 mRNA. LAT1 mRNA levels were higher in MCF-7 cells than in MDA-MB-231 cells. Furthermore, LAT1 mRNA was more abundant than CD98hc mRNA in both MDA-MB-231 and MCF-7 cells. The results suggest that system L is the major transporter for L-leucine in both MDA-MB-231 and MCF-7 cells. It is possible that LAT1 may be the major molecular correlate of system L in both cell types. However, not all of the properties of system L reflected those of LAT1/LAT2/CD98hc. PMID:15328053

  14. Physical exercise and a leucine-rich diet modulate the muscle protein metabolism in Walker tumor-bearing rats.

    PubMed

    Salomão, Emilianne M; Toneto, Aline T; Silva, Gisele O; Gomes-Marcondes, Maria Cristina C

    2010-01-01

    Leucine-supplemented diet can recover lean body mass and preserve muscle protein mass. Additionally, physical exercise can be an excellent alternative to improve the rehabilitation of cancer patients. Knowing these facts, we examined the effects of a leucine-rich diet with or without physical aerobic exercise on muscle protein metabolism in Walker tumor-bearing rats. Young rats were divided into 4 groups that did or did not perform light aerobic exercise (swim training) and were on a leucine-rich diet or a control diet for 2 mo. After this time, these animals were implanted or not with tumors (subcutaneously) following groups for either control diet or leucine-rich diet fed rats: control, trained, tumor-bearing, and trained tumor-bearing. Twenty-one days after implantation, the tumor growth induced a decrease in the muscle protein synthesis and increased the catabolic process, which was associated with an increase in the expression of the ubiquitin-proteasome subunits (20S, 19S, and 11S). In contrast, the exercise program minimized the muscle degradation process and increased muscle myosin content. Additionally, leucine supplementation also modulated proteasome subunits, especially the 19S and 11S. In summary, the exercise has beneficial effects by reducing tumor growth, leading to an improvement in protein turnover especially when in conjunction with a leucine-rich diet. PMID:21058197

  15. Life-Span Exposure to Low Doses of Aspartame Beginning during Prenatal Life Increases Cancer Effects in Rats

    PubMed Central

    Soffritti, Morando; Belpoggi, Fiorella; Tibaldi, Eva; Esposti, Davide Degli; Lauriola, Michelina

    2007-01-01

    Background In a previous study conducted at the Cesare Maltoni Cancer Research Center of the European Ramazzini Foundation (CMCRC/ERF), we demonstrated for the first time that aspartame (APM) is a multipotent carcinogenic agent when various doses are administered with feed to Sprague-Dawley rats from 8 weeks of age throughout the life span. Objective The aim of this second study is to better quantify the carcinogenic risk of APM, beginning treatment during fetal life. Methods We studied groups of 70–95 male and female Sprague-Dawley rats administered APM (2,000, 400, or 0 ppm) with feed from the 12th day of fetal life until natural death. Results Our results show a) a significant dose-related increase of malignant tumor–bearing animals in males (p < 0.01), particularly in the group treated with 2,000 ppm APM (p < 0.01); b) a significant increase in incidence of lymphomas/leukemias in males treated with 2,000 ppm (p < 0.05) and a significant dose-related increase in incidence of lymphomas/leukemias in females (p < 0.01), particularly in the 2,000-ppm group (p < 0.01); and c) a significant dose-related increase in incidence of mammary cancer in females (p < 0.05), particularly in the 2,000-ppm group (p < 0.05). Conclusions The results of this carcinogenicity bioassay confirm and reinforce the first experimental demonstration of APM’s multipotential carcinogenicity at a dose level close to the acceptable daily intake for humans. Furthermore, the study demonstrates that when life-span exposure to APM begins during fetal life, its carcinogenic effects are increased. PMID:17805418

  16. Impact of Leucine Supplementation on Exercise Training Induced Anti-Cardiac Remodeling Effect in Heart Failure Mice

    PubMed Central

    de Moraes, Wilson Max Almeida Monteiro; Melara, Thaís Plasti; de Souza, Pamella Ramona Moraes; de Salvi Guimarães, Fabiana; Bozi, Luiz Henrique Marchesi; Brum, Patricia Chakur; Medeiros, Alessandra

    2015-01-01

    Leucine supplementation potentiates the effects of aerobic exercise training (AET) on skeletal muscle; however, its potential effects associated with AET on cardiac muscle have not been clarified yet. We tested whether leucine supplementation would potentiate the anti-cardiac remodeling effect of AET in a genetic model of sympathetic hyperactivity-induced heart failure in mice (α2A/α2CARKO). Mice were assigned to five groups: wild type mice treated with placebo and sedentary (WT, n = 11), α2A/α2CARKO treated with placebo and sedentary (KO, n = 9), α2A/α2CARKO treated with leucine and sedentary (KOL, n = 11), α2A/α2CARKO treated with placebo and AET (KOT, n = 12) or α2A/α2CARKO treated with leucine and AET (KOLT, n = 12). AET consisted of four weeks on a treadmill with 60 min sessions (six days/week, 60% of maximal speed) and administration by gavage of leucine (1.35 g/kg/day) or placebo (distilled water). The AET significantly improved exercise capacity, fractional shortening and re-established cardiomyocytes’ diameter and collagen fraction in KOT. Additionally, AET significantly prevented the proteasome hyperactivity, increased misfolded proteins and HSP27 expression. Isolated leucine supplementation displayed no effect on cardiac function and structure (KOL), however, when associated with AET (KOLT), it increased exercise tolerance to a higher degree than isolated AET (KOT) despite no additional effects on AET induced anti-cardiac remodeling. Our results provide evidence for the modest impact of leucine supplementation on cardiac structure and function in exercised heart failure mice. Leucine supplementation potentiated AET effects on exercise tolerance, which might be related to its recognized impact on skeletal muscle. PMID:25988767

  17. Leucine: tRNA Ligase from Cultured Cells of Nicotiana tabacum var. Xanthi

    PubMed Central

    Gore, Nigel R.; Wray, John L.

    1978-01-01

    Leucine:tRNA ligase was assayed in extracts from cultured tobacco (Nicotiana tabacum) XD cells by measuring the initial rate of aminoacylation of transfer RNA with l-[4,5-3H]leucine. Transfer RNA was purified from tobacco XD cells after the method of Vanderhoef et al. (Phytochemistry 9: 2291-2304). The buoyant density of leucine:tRNA ligase from cells grown for 100 generations in 2.5 mm [15N]nitrate and 30% deuterium oxide was 1.3397. After transfer of cells into light medium (2.5 mm [14N]nitrate and 100% H2O) the ligase activity increased and the buoyant density decreased with time to 1.3174 at 72 hours after transfer. It was concluded that leucine:tRNA ligase molecules were synthesized de novo from light amino acids during the period of activity increase. The width at half-peak height of the enzyme distribution profiles following isopycnic equilibrium centrifugation in caesium chloride remained constant at all times after transfer into light medium providing evidence for the loss of preexisting functional ligase molecules. It was concluded that during the period of activity increase the cellular level of enzyme activity was determined by a balance between de novo synthesis and the loss of functional enzyme molecules due to either inactivation or degradation. PMID:16660229

  18. Assessment of the metabolic chiral inversion of D-leucine in rat by gas chromatography-mass spectrometry combined with a stable isotope dilution analysis.

    PubMed

    Hasegawa, H; Matsukawa, T; Shinohara, Y; Hashimoto, T

    2000-08-01

    The stereoselective pharmacokinetics of leucine enantiomers in rats has been investigated to evaluate the inversion of D-leucine to L-enantiomer. After a bolus i.v. administration of D- or L-[2H7]leucine to rats, blood samples were obtained over 6 h after administration and analyzed by a stereoselective gas chromatography-mass spectrometry method. Racemic [2H3]leucine was used as an internal standard. The method involved methyl esterification and subsequent chiral derivatization with (+)-alpha-methoxy-alpha-trifluoromethylphenylacetyl chloride to form the diastereomeric amide. The derivatization made possible the separation of leucine enantiomers with good gas chromatographic behavior. Plasma concentration of both D- and L-[2H7]leucine declined biexponentially, with elimination half-lives of 60 and 14 min, respectively. In contrast to the L-enantiomer, the D-enantiomer had a lower systemic clearance. When D-[2H7]leucine was administered, the L-enantiomer was found to rapidly appear in plasma. About 30% of an administered dose of the D-isomer was stereospecifically inverted to the L-enantiomer. There was no measurable inversion of the L- to D-enantiomer. This methodology has made it possible to evaluate the pharmacokinetics of each enantiomer of amino acids and estimate of chiral inversion after administration of D-amino acids. PMID:10901701

  19. Protein and leucine metabolism in maple syrup urine disease

    SciTech Connect

    Thompson, G.N.; Bresson, J.L.; Pacy, P.J.; Bonnefont, J.P.; Walter, J.H.; Leonard, J.V.; Saudubray, J.M.; Halliday, D. )

    1990-04-01

    Constant infusions of (13C)leucine and (2H5)phenylalanine were used to trace leucine and protein kinetics, respectively, in seven children with maple syrup urine disease (MSUD) and eleven controls matched for age and dietary protein intake. Despite significant elevations of plasma leucine (mean 351 mumol/l, range 224-477) in MSUD subjects, mean whole body protein synthesis (3.78 +/- 0.42 (SD) g.kg-1. 24 h-1) and catabolism (4.07 +/- 0.46) were similar to control values (3.69 +/- 0.50 and 4.09 +/- 0.50, respectively). The relationship between phenylalanine and leucine fluxes was also similar in MSUD subjects (mean phenylalanine-leucine flux ratio 0.35 +/- 0.07) and previously reported adult controls (0.33 +/- 0.02). Leucine oxidation was undetectable in four of the MSUD subjects and very low in the other three (less than 4 mumol.kg-1.h-1; controls 13-20). These results show that persistent elevation in leucine concentration has no effect on protein synthesis. The marked disturbance in leucine metabolism in MSUD did not alter the relationship between rates of catabolism of protein to phenylalanine and leucine, which provides further support for the validity of the use of a single amino acid to trace whole body protein metabolism. The minimal leucine oxidation in MSUD differs from findings in other inborn metabolic errors and indicates that in patients with classical MSUD there is no significant route of leucine disposal other than through protein synthesis.

  20. Ceruletide increases dose dependently both jejunal motor activity and threshold and tolerance to experimentally induced pain in healthy man.

    PubMed Central

    Stacher, G; Steinringer, H; Schmierer, G; Schneider, C; Winklehner, S; Mittelbach, G; De Paolis, C; Praga, C

    1984-01-01

    The effects of ceruletide on jejunal motility and experimentally induced pain were studied in 16 healthy men, who participated each in four experiments and received in random double blind fashion 5, 10, or 20 micrograms ceruletide intramuscularly or placebo. Jejunal pressures were recorded by three perfused catheters with orifices between 10 and 20 cm aboral of the ligament of Treitz. Ceruletide dose dependently diminished phase I and increased phase II type activity and tended to reduce the number, but not the duration, of activity fronts. The number and amplitude of contractions as well as the area under the curve increased significantly and dose dependently as did threshold and tolerance to electrically and threshold to thermally induced pain. Only mild sedative and other side effects occurred. PMID:6714795

  1. Investigations on particle surface characteristics vs. dispersion behaviour of L-leucine coated carrier-free inhalable powders.

    PubMed

    Raula, Janne; Thielmann, Frank; Naderi, Majid; Lehto, Vesa-Pekka; Kauppinen, Esko I

    2010-01-29

    Aerosol microparticles of salbutamol sulphate are gas-phase coated with an amino acid L-leucine. Depending of the saturated state of L-leucine, the coating is formed by the surface diffusion of L-leucine molecules within a droplet or by the physical vapour deposition (PVD) of L-leucine or by the combination thereof. The PVD coated particles showed excellent aerosolization characteristics in a carrier-free powder delivery from an inhaler. The aerosolization of the fine powders is compared with surface energy parameters analysed by inverse gas chromatography (IGC). The dispersion testing is conducted by a Inhalation Simulator using a fast inhalation profile with inhalation flow rate of 67 l min(-1). It is found that the powder emission is affected by the morphology, surface roughness (asperity size and density) of the particles and acidity of particle surface. The latter affects the dispersion and dose repeatability of fine powder in a case if L-leucine content is high enough. However, there is no direct correlation between dispersive surface energies and aerosolization performances of the powders. Crucial factors for the improved aerosolization rely weakly on surface acid-base properties but strongly on particle morphology and fine-scale surface roughness. PMID:19879344

  2. Pushing product formation to its limit: metabolic engineering of Corynebacterium glutamicum for L-leucine overproduction.

    PubMed

    Vogt, Michael; Haas, Sabine; Klaffl, Simon; Polen, Tino; Eggeling, Lothar; van Ooyen, Jan; Bott, Michael

    2014-03-01

    Using metabolic engineering, an efficient L-leucine production strain of Corynebacterium glutamicum was developed. In the wild type of C. glutamicum, the leuA-encoded 2-isopropylmalate synthase (IPMS) is inhibited by low L-leucine concentrations with a K(i) of 0.4 mM. We identified a feedback-resistant IMPS variant, which carries two amino acid exchanges (R529H, G532D). The corresponding leuA(fbr) gene devoid of the attenuator region and under control of a strong promoter was integrated in one, two or three copies into the genome and combined with additional genomic modifications aimed at increasing L-leucine production. These modifications involved (i) deletion of the gene encoding the repressor LtbR to increase expression of leuBCD, (ii) deletion of the gene encoding the transcriptional regulator IolR to increase glucose uptake, (iii) reduction of citrate synthase activity to increase precursor supply, and (iv) introduction of a gene encoding a feedback-resistant acetohydroxyacid synthase. The production performance of the resulting strains was characterized in bioreactor cultivations. Under fed-batch conditions, the best producer strain accumulated L-leucine to levels exceeding the solubility limit of about 24 g/l. The molar product yield was 0.30 mol L-leucine per mol glucose and the volumetric productivity was 4.3 mmol l⁻¹ h⁻¹. These values were obtained in a defined minimal medium with a prototrophic and plasmid-free strain, making this process highly interesting for industrial application. PMID:24333966

  3. Leucine acts as a nutrient signal to stimulate protein synthesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The postprandial rise in amino acids and insulin independently stimulates protein synthesis in skeletal muscle of piglets. Leucine is an important mediator of the response to amino acids. We have shown that the postprandial rise in leucine, but not isoleucine or valine, acutely stimulates muscle pro...

  4. 21 CFR 862.1460 - Leucine aminopeptidase test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Leucine aminopeptidase test system. 862.1460 Section 862.1460 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1460 Leucine aminopeptidase...

  5. Novel Dosing Strategies Increase Exposures of the Potent Antituberculosis Drug Rifapentine but Are Poorly Tolerated in Healthy Volunteers

    PubMed Central

    Savic, Radojka M.; Park, Jeong-Gun; Cramer, Yoninah; Hafner, Richard; Hogg, Evelyn; Janik, Jennifer; Marzinke, Mark A.; Patterson, Kristine; Benson, Constance A.; Hovind, Laura; Dorman, Susan E.; Haas, David W.

    2015-01-01

    Rifapentine is a potent antituberculosis drug currently in phase III trials. Bioavailability decreases with increasing dose, yet high daily exposures are likely needed to improve efficacy and shorten the tuberculosis treatment duration. Further, the limits of tolerability are poorly defined. The phase I multicenter trial in healthy adults described here investigated two strategies to increase rifapentine exposures: dividing the dose or giving the drug with a high-fat meal. In arm 1, rifapentine was administered at 10 mg/kg of body weight twice daily and 20 mg/kg once daily, each for 14 days, separated by a 28-day washout; the dosing sequence was randomized. In arm 2, 15 mg/kg rifapentine once daily was given with a high-fat versus a low-fat breakfast. Sampling for pharmacokinetic analysis was performed on days 1 and 14. Population pharmacokinetic analyses were performed. This trial was stopped early for poor tolerability and because of safety concerns. Of 44 subjects, 20 discontinued prematurely; 11 of these discontinued for protocol-defined toxicity (a grade 3 or higher adverse event or grade 2 or higher rifamycin hypersensitivity). Taking rifapentine with a high-fat meal increased the median steady-state area under the concentration-time curve from time zero to 24 h (AUC0–24ss) by 31% (relative standard error, 6%) compared to that obtained when the drug was taken with a low-fat breakfast. Dividing the dose increased exposures substantially (e.g., 38% with 1,500 mg/day). AUC0–24ss was uniformly higher in our study than in recent tuberculosis treatment trials, in which toxicity was rare. In conclusion, two strategies to increase rifapentine exposures, dividing the dose or giving it with a high-fat breakfast, successfully increased exposures, but toxicity was common in healthy adults. The limits of tolerability in patients with tuberculosis remain to be defined. (AIDS Clinical Trials Group study A5311 has been registered at ClinicalTrials.gov under registration

  6. Leucine minimizes denervation-induced skeletal muscle atrophy of rats through akt/mtor signaling pathways

    PubMed Central

    Ribeiro, Carolina B.; Christofoletti, Daiane C.; Pezolato, Vitor A.; de Cássia Marqueti Durigan, Rita; Prestes, Jonato; Tibana, Ramires A.; Pereira, Elaine C. L.; de Sousa Neto, Ivo V.; Durigan, João L. Q.; da Silva, Carlos A.

    2015-01-01

    The aim of the present study was to evaluate the effect of leucine treatment (0.30 mM) on muscle weight and signaling of myoproteins related to synthesis and degradation pathways of soleus muscle following seven days of complete sciatic nerve lesion. Wistar rats (n = 24) of 3–4 months of age (192 ± 23 g) were used. The animals were randomly distributed into four experimental groups (n = 6/group): control, treated with leucine (L), denervated (D) and denervated treated with leucine (DL). Dependent measures were proteins levels of AKT, AMPK, mTOR, and ACC performed by Western blot. Leucine induced a reduction in the phosphorylation of AMPK (p < 0.05) by 16% in the L and by 68% in the DL groups as compared with control group. Denervation increased AMPK by 24% in the D group as compared with the control group (p < 0.05). AKT was also modulated by denervation and leucine treatment, highlighted by the elevation of AKT phosphorylation in the D (65%), L (98%) and DL (146%) groups as compared with the control group (p < 0.05). AKT phosphorylation was 49% higher in the D group as compared with the DL group. Furthermore, denervation decreased mTOR phosphorylation by 29% in the D group as compared with the control group. However, leucine treatment induced an increase of 49% in the phosphorylation of mTOR in the L group as compared with the control group, and an increase of 154% in the DL as compared with the D group (p < 0.05). ACC phosphorylation was 20% greater in the D group than the control group. Furthermore, ACC in the soleus was 22% lower in the in the L group and 50% lower in the DL group than the respective control group (p < 0.05). In conclusion, leucine treatment minimized the deleterious effects of denervation on rat soleus muscle by increasing anabolic (AKT and mTOR) and decreasing catabolic (AMPK) pathways. These results may be interesting for muscle recovery following acute denervation, which may contribute to musculoskeletal rehabilitation after denervation

  7. Leucine-rich glioma-inactivated protein 1 antibody encephalitis

    PubMed Central

    Mayasi, Yunis; Takhtani, Deepak

    2014-01-01

    Objective: To describe a case of leucine-rich glioma-inactivated protein 1 (LGI1) antibody–associated encephalitis. Methods: The clinical and ancillary data and brain MRIs were gathered retrospectively by chart review. Relevant literature on similar cases was also reviewed. Results: The diagnosis of LGI1 antibody–associated autoimmune encephalitis was based on the typical clinical presentation of seizures, psychiatric symptoms, and memory loss as well as negative diagnostic testing for cancer; the diagnosis was confirmed by positive LGI1 antibody. The patient responded favorably to treatment with IV immunoglobulin and continues to do well. Conclusion: LGI1 antibody–associated encephalitis has increasingly been recognized as a primary autoimmune disorder with good prognosis and response to treatment. PMID:25520958

  8. Leucine for retention of lean mass on a hypocaloric diet.

    PubMed

    Jitomir, Jean; Willoughby, Darryn S

    2008-12-01

    As obesity rates continue to climb, there is a pressing need for novel weight loss techniques. However, the energy-restricted diets recommended for weight loss typically result in significant amounts of lean tissue loss, in addition to the desired body fat loss. Leucine, a supported anticatabolic agent, has shown promise in research at many levels. First, leucine is known to stimulate the mammalian target of rapamycin pathway, which initiates translation and protein synthesis in muscle cells. Furthermore, leucine may help to regulate blood glucose levels by promoting gluconeogenesis. Finally, several recent studies provide evidence that leucine aids in the retention of lean mass in a hypocaloric state. The aim of this paper is to review relevant leucine research in the three areas described and assess its potential as supplement for obese individuals. PMID:19053849

  9. An increase of serum lipids after cumulative doses of doxorubicin and epirubicin in experimental animals.

    PubMed

    Stathopoulos, G P; Papadopoulos, N G; Stephanopoulou, A; Dontas, I; Kotsarelis, D; Karayannacos, P E

    1996-01-01

    A wide range of pharmacological actions has been attributed to the anthracyclins. In this study we examined their effect on serum lipids in experimental animals in parallel with histological alterations. Three Wistar rat groups were injected with doxorubicin, epirubicin or normal saline once a week for 12 weeks. Total serum lipids, cholesterol, triglycerides, HDL-cholesterol, transaminases, proteins and alkaline phosphatase were assayed weekly. A proportion of the animals were sacrificed at the same time points and the cardiac muscle, large vessels, liver and abdominal muscle were stained and examined under light microscopy. Serum lipids were found to increase gradually, starting after 8 weeks of drug administration, until the end of the experiment. Tissue damage was noted in the cardiac muscle, abdominal muscle and large vessels, also following an increasing trend. Doxorubicin had a more pronounced effect than epirubicin on both serum lipid increase and tissue destruction. These alterations may contribute to anthracyclin-related cardiac damage. PMID:9042202

  10. Dose Relations between Goal Setting, Theory-Based Correlates of Goal Setting and Increases in Physical Activity during a Workplace Trial

    ERIC Educational Resources Information Center

    Dishman, Rod K.; Vandenberg, Robert J.; Motl, Robert W.; Wilson, Mark G.; DeJoy, David M.

    2010-01-01

    The effectiveness of an intervention depends on its dose and on moderators of dose, which usually are not studied. The purpose of the study is to determine whether goal setting and theory-based moderators of goal setting had dose relations with increases in goal-related physical activity during a successful workplace intervention. A…

  11. Acute prenatal exposure to a moderate dose of valproic acid increases social behavior and alters gene expression in rats.

    PubMed

    Cohen, Ori S; Varlinskaya, Elena I; Wilson, Carey A; Glatt, Stephen J; Mooney, Sandra M

    2013-12-01

    Prenatal exposure to moderate doses of valproic acid (VPA) produces brainstem abnormalities, while higher doses of this teratogen elicit social deficits in the rat. In this pilot study, we examined effects of prenatal exposure to a moderate dose of VPA on behavior and on transcriptomic expression in three brain regions that mediate social behavior. Pregnant Long Evans rats were injected with 350 mg/kg VPA or saline on gestational day 13. A modified social interaction test was used to assess social behavior and social preference/avoidance during early and late adolescence and in adulthood. VPA-exposed animals demonstrated more social investigation and play fighting than control animals. Social investigation, play fighting, and contact behavior also differed as a function of age; the frequency of these behaviors increased in late adolescence. Social preference and locomotor activity under social circumstances were unaffected by treatment or age. Thus, a moderate prenatal dose of VPA produces behavioral alterations that are substantially different from the outcomes that occur following exposure to a higher dose. At adulthood, VPA-exposed subjects exhibited transcriptomic abnormalities in three brain regions: anterior amygdala, cerebellar vermis, and orbitofrontal cortex. A common feature among the proteins encoded by the dysregulated genes was their ability to be modulated by acetylation. Analysis of the expression of individual exons also revealed that genes involved in post-translational modification and epigenetic regulation had particular isoforms that were ubiquitously dysregulated across brain regions. The vulnerability of these genes to the epigenetic effects of VPA may highlight potential mechanisms by which prenatal VPA exposure alters the development of social behavior. PMID:24055786

  12. High-Dose Testosterone Treatment Increases Serotonin Transporter Binding in Transgender People

    PubMed Central

    Kranz, Georg S.; Wadsak, Wolfgang; Kaufmann, Ulrike; Savli, Markus; Baldinger, Pia; Gryglewski, Gregor; Haeusler, Daniela; Spies, Marie; Mitterhauser, Markus; Kasper, Siegfried; Lanzenberger, Rupert

    2015-01-01

    Background Women are two times more likely to be diagnosed with depression than men. Sex hormones modulating serotonergic transmission are proposed to partly underlie these epidemiologic findings. Here, we used the cross-sex steroid hormone treatment of transsexuals seeking sex reassignment as a model to investigate acute and chronic effects of testosterone and estradiol on serotonin reuptake transporter (SERT) binding in female-to-male and male-to-female transsexuals. Methods Thirty-three transsexuals underwent [11C]DASB positron emission tomography before start of treatment, a subset of which underwent a second scan 4 weeks and a third scan 4 months after treatment start. SERT nondisplaceable binding potential was quantified in 12 regions of interest. Treatment effects were analyzed using linear mixed models. Changes of hormone plasma levels were correlated with changes in regional SERT nondisplaceable binding potential. Results One and 4 months of androgen treatment in female-to-male transsexuals increased SERT binding in amygdala, caudate, putamen, and median raphe nucleus. SERT binding increases correlated with treatment-induced increases in testosterone levels, suggesting that testosterone increases SERT expression on the cell surface. Conversely, 4 months of antiandrogen and estrogen treatment in male-to-female transsexuals led to decreases in SERT binding in insula, anterior, and mid-cingulate cortex. Increases in estradiol levels correlated negatively with decreases in regional SERT binding, indicating a protective effect of estradiol against SERT loss. Conclusions Given the central role of the SERT in the treatment of depression and anxiety disorders, these findings may lead to new treatment modalities and expand our understanding of the mechanism of action of antidepressant treatment properties. PMID:25497691

  13. Effect of hyperglucagonemia on whole-body leucine metabolism in immature pigs before and during a meal

    SciTech Connect

    Ostaszewski, P.; Nissen, S. )

    1988-03-01

    Leucine metabolism was measured isotopically in 12 immature female pigs to assess the effect of acute hyperglucagonemia on leucine kinetics in both the fed and fasting states. After an overnight fast, immature pigs were infused with {alpha}-({sup 3}H)ketoisocaproate and ({sup 14}C)leucine. After a 2-h equilibration period, an infusion of either saline or 7 pg {center dot} kg{sup {minus}1} {center dot} min{sup {minus}1} of glucagon was begun, which increased plasma glucagon from {approximately}140 to {approximately}640 pg/ml and doubled the insulin concentrations. Two hours later, pigs were fed small meals to which (5,5,5-{sup 2}H{sub 3})leucine was added to trace absorption. By subtracting absorption from total leucine flux, an estimate of endogenous proteolysis during the meal was made. In the fasting state, glucagon increased proteolysis and increased oxidation. No significant glucagon-related changes in any other flux parameters occurred in the fasting state. Ingestion of the meals caused oxidation to increase 41% in control animals, whereas in glucagon-infused animals, oxidation increased 84%. Additional, animals infused with glucagon suppressed endogenous proteolysis 43% after the meal compared with 55% decrease in control animals. These data indicate that glucagon stimulates whole-body proteolysis in both the fasting and fed states.

  14. Change of teicoplanin loading dose requirement for incremental increases of systemic inflammatory response syndrome score in the setting of sepsis.

    PubMed

    Nakano, Takafumi; Nakamura, Yoshihiko; Takata, Tohru; Irie, Keiichi; Sano, Kazunori; Imakyure, Osamu; Mishima, Kenichi; Futagami, Koujiro

    2016-08-01

    Background Target trough concentrations are recommended for teicoplanin (TEIC) to minimize its adverse effects and to maximize efficacy in sepsis caused by grampositive cocci, including methicillin-resistant Staphylococcus aureus infection. However, optimal doses to attain proper trough values in patients with sepsis have not yet been well established for TEIC. Objective This study investigated whether the systemic inflammatory response syndrome (SIRS) score could predict the pharmacokinetics of TEIC in patients with sepsis. Setting This study was conducted at Fukuoka University Hospital in Japan. Methods We retrospectively reviewed the records of patients using TEIC between April 2012 and March 2015. SIRS positive was defined as infection with a SIRS score ≥2. Estimates of pharmacokinetic parameters were calculated using a Bayesian method. Creatinine clearance rates were estimated by the Cockcroft-Gault formula (eCcr). Main outcome measure Change of TEIC loading dose requirement for incremental increases of SIRS score. Results In total, 133 patients were enrolled: 50 non-SIRS patients and 83 patients with SIRS. The TEIC plasma trough concentration was significantly lower in SIRS than non-SIRS patients (15.7 ± 7.1 vs. 20.1 ± 8.6 μg/mL; P < 0.01), although there was no significant difference in the loading dose administered. Moreover, SIRS scores were increasingly predictive of eCcr and TEIC clearance in a stepwise manner. To achieve the target trough concentration (15-30 μg/mL), the optimal doses required in non-SIRS versus SIRS patients were 12-24 versus 18-30 mg/kg/day, respectively, during the first 48 h. Conclusions These findings suggest that the pharmacokinetics of TEIC are altered in SIRS patients, who required higher doses than non-SIRS patients to achieve the target trough concentration. We suggest that the SIRS score can become a new modality to determine the initial TEIC loading dose. PMID:27125378

  15. Leucine-Enriched Essential Amino Acids Augment Mixed Protein Synthesis, But Not Collagen Protein Synthesis, in Rat Skeletal Muscle after Downhill Running.

    PubMed

    Kato, Hiroyuki; Suzuki, Hiromi; Inoue, Yoshiko; Suzuki, Katsuya; Kobayashi, Hisamine

    2016-01-01

    Mixed and collagen protein synthesis is elevated for as many as 3 days following exercise. Immediately after exercise, enhanced amino acid availability increases synthesis of mixed muscle protein, but not muscle collagen protein. However, the potential for synergic effects of amino acid ingestion with exercise on both mixed and collagen protein synthesis remains unclear. We investigated muscle collagen protein synthesis in rats following post-exercise ingestion of leucine-enriched essential amino acids. We determined fractional protein synthesis rates (FSR) at different time points following exercise. Mixed protein and collagen protein FSRs in skeletal muscle were determined by measuring protein-bound enrichments of hydroxyproline and proline, and by measuring the intracellular enrichment of proline, using injections of flooding d₃-proline doses. A leucine-enriched mixture of essential amino acids (or distilled water as a control) was administrated 30 min or 1 day post-exercise. The collagen protein synthesis in the vastus lateralis was elevated for 2 days after exercise. Although amino acid administration did not increase muscle collagen protein synthesis, it did lead to augmented mixed muscle protein synthesis 1 day following exercise. Thus, contrary to the regulation of mixed muscle protein synthesis, muscle collagen protein synthesis is not affected by amino acid availability after damage-inducing exercise. PMID:27367725

  16. Leucine-Enriched Essential Amino Acids Augment Mixed Protein Synthesis, But Not Collagen Protein Synthesis, in Rat Skeletal Muscle after Downhill Running

    PubMed Central

    Kato, Hiroyuki; Suzuki, Hiromi; Inoue, Yoshiko; Suzuki, Katsuya; Kobayashi, Hisamine

    2016-01-01

    Mixed and collagen protein synthesis is elevated for as many as 3 days following exercise. Immediately after exercise, enhanced amino acid availability increases synthesis of mixed muscle protein, but not muscle collagen protein. However, the potential for synergic effects of amino acid ingestion with exercise on both mixed and collagen protein synthesis remains unclear. We investigated muscle collagen protein synthesis in rats following post-exercise ingestion of leucine-enriched essential amino acids. We determined fractional protein synthesis rates (FSR) at different time points following exercise. Mixed protein and collagen protein FSRs in skeletal muscle were determined by measuring protein-bound enrichments of hydroxyproline and proline, and by measuring the intracellular enrichment of proline, using injections of flooding d3-proline doses. A leucine-enriched mixture of essential amino acids (or distilled water as a control) was administrated 30 min or 1 day post-exercise. The collagen protein synthesis in the vastus lateralis was elevated for 2 days after exercise. Although amino acid administration did not increase muscle collagen protein synthesis, it did lead to augmented mixed muscle protein synthesis 1 day following exercise. Thus, contrary to the regulation of mixed muscle protein synthesis, muscle collagen protein synthesis is not affected by amino acid availability after damage-inducing exercise. PMID:27367725

  17. Regions of the Bacillus subtilis ilv-leu operon involved in regulation by leucine.

    PubMed Central

    Grandoni, J A; Fulmer, S B; Brizzio, V; Zahler, S A; Calvo, J M

    1993-01-01

    The ilv-leu operon of Bacillus subtilis is regulated in part by transcription attenuation. The cis-acting elements required for regulation by leucine lie within a 683-bp fragment of DNA from the region upstream of ilvB, the first gene of the operon. This fragment contains the ilv-leu promoter and 482 bp of the ilv-leu leader region. Spontaneous mutations that lead to increased expression of the operon were shown to lie in an imperfect inverted repeat encoding the terminator stem within the leader region. Mutations within the inverted repeat of the terminator destroyed most of the leucine-mediated repression. The remaining leucine-mediated repression probably resulted from a decrease in transcription initiation. A systematic analysis of other deletions within the ilv-leu leader region identified a 40-bp region required for the derepression that occurred during leucine limitation. This region lies within a potential RNA stem-and-loop structure that is probably required for leucine-dependent control. Deletion analysis also suggested that alternate secondary structures proximal to the terminator are involved in allowing transcription to proceed beyond the terminator. Additional experiments suggested that attenuation of the ilv-leu operon is not dependent on coupling translation to transcription of the leader region. Our data support a model proposed by Grundy and Henkin (F. J. Grundy and T. M. Henkin, Cell 74:475-482, 1993) in which uncharged tRNA acts as a positive regulatory factor to increase gene expression during amino acid limitation. Images PMID:8244927

  18. Increased efficacy of a trivalent nicotine vaccine compared to a dose-matched monovalent vaccine when formulated with alum.

    PubMed

    de Villiers, Sabina H L; Cornish, Katherine E; Troska, Andrew J; Pravetoni, Marco; Pentel, Paul R

    2013-12-16

    Vaccination against nicotine is a potential treatment for tobacco smoking. Clinical trials show effect only in high antibody responders; therefore it is necessary to increase the effectiveness of nicotine vaccines. The use of a multivalent vaccine that activates several B cell populations is a possible approach to increase antibody response. The aim of this study was to investigate whether three different nicotine immunogens could be mixed to generate independent responses resulting in additive antibody titers, and whether this would alter nicotine distribution to a greater extent than antibodies generated by a monovalent vaccine. When immunogens were administered s.c. with alum adjuvant, the trivalent vaccine generated significantly higher titers and prevented the distribution of an i.v. nicotine dose to brain to a greater extent than an equivalent dose of a monovalent vaccine. The number of rats with antibody titers >1:10,000 was significantly increased in the trivalent group compared to the monovalent group. There were no correlations between the titers generated by the different nicotine immunogens in the trivalent vaccine, supporting the hypothesis that the immunogens generated independent responses from distinct populations of B cells. In contrast, when administered i.p. in Freund's adjuvant, the trivalent nicotine vaccine was not more immunogenic than its component monovalent vaccine. Vaccine immunogenicity was suppressed if unconjugated protein was added to the monovalent vaccine formulated in Freund's adjuvant, compared to monovalent vaccine alone. These data suggest a protein-protein interaction that affects titers negatively and is apparent when the vaccines are formulated with Freund's adjuvant. In summary, a trivalent nicotine vaccine formulated with alum showed significantly higher efficacy than a dose-matched monovalent vaccine and may offer a strategy for increasing nicotine vaccine immunogenicity. This approach may be generalizable to other

  19. l-Ala-γ-d-Glu-meso-diaminopimelic Acid (DAP) Interacts Directly with Leucine-rich Region Domain of Nucleotide-binding Oligomerization Domain 1, Increasing Phosphorylation Activity of Receptor-interacting Serine/Threonine-protein Kinase 2 and Its Interaction with Nucleotide-binding Oligomerization Domain 1*

    PubMed Central

    Laroui, Hamed; Yan, Yutao; Narui, Yoshie; Ingersoll, Sarah A.; Ayyadurai, Saravanan; Charania, Moiz A.; Zhou, Feimeng; Wang, Binghe; Salaita, Khalid; Sitaraman, Shanthi V.; Merlin, Didier

    2011-01-01

    The oligopeptide transporter PepT1 expressed in inflamed colonic epithelial cells transports small bacterial peptides, such as muramyl dipeptide (MDP) and l-Ala-γ-d-Glu-meso-diaminopimelic acid (Tri-DAP) into cells. The innate immune system uses various proteins to sense pathogen-associated molecular patterns. Nucleotide-binding oligomerization domain (NOD)-like receptors of which there are more than 20 related family members are present in the cytosol and recognize intracellular ligands. NOD proteins mediate NF-κB activation via receptor-interacting serine/threonine-protein kinase 2 (RICK or RIPK). The specific ligands for some NOD-like receptors have been identified. NOD type 1 (NOD1) is activated by peptides that contain a diaminophilic acid, such as the PepT1 substrate Tri-DAP. In other words, PepT1 transport activity plays an important role in controlling intracellular loading of ligands for NOD1 in turn determining the activation level of downstream inflammatory pathways. However, no direct interaction between Tri-DAP and NOD1 has been identified. In the present work, surface plasmon resonance and atomic force microscopy experiments showed direct binding between NOD1 and Tri-DAP with a Kd value of 34.5 μm. In contrast, no significant binding was evident between muramyl dipeptide and NOD1. Furthermore, leucine-rich region (LRR)-truncated NOD1 did not interact with Tri-DAP, indicating that Tri-DAP interacts with the LRR domain of NOD1. Next, we examined binding between RICK and NOD1 proteins and found that such binding was significant with a Kd value of 4.13 μm. However, NOD1/RICK binding was of higher affinity (Kd of 3.26 μm) when NOD1 was prebound to Tri-DAP. Furthermore, RICK phosphorylation activity was increased when NOD was prebound to Tri-DAP. In conclusion, we have shown that Tri-DAP interacts directly with the LRR domain of NOD1 and consequently increases RICK/NOD1 association and RICK phosphorylation activity. PMID:21757725

  20. Reduced cerebral glucose metabolism and increased brain capillary permeability following high-dose methotrexate chemotherapy: a positron emission tomographic study

    SciTech Connect

    Phillips, P.C.; Dhawan, V.; Strother, S.C.; Sidtis, J.J.; Evans, A.C.; Allen, J.C.; Rottenberg, D.A.

    1987-01-01

    Regional glucose metabolic rate constants and blood-to-brain transport of rubidium were estimated using positron emission tomography in an adolescent patient with a brain tumor, before and after chemotherapy with intravenous high-dose methotrexate. Widespread depression of cerebral glucose metabolism was apparent 24 hours after drug administration, which may reflect reduced glucose phosphorylation, and the influx rate constant for /sup 82/Rb was increased, indicating a drug-induced alteration in blood-brain barrier function. Associated changes in neuropsychological performance, electroencephalogram, and plasma amino acid concentration were identified in the absence of evidence of systemic methotrexate toxicity, suggesting primary methotrexate neurotoxicity.

  1. Leucine and Protein Metabolism in Obese Zucker Rats

    PubMed Central

    She, Pengxiang; Olson, Kristine C.; Kadota, Yoshihiro; Inukai, Ayami; Shimomura, Yoshiharu; Hoppel, Charles L.; Adams, Sean H.; Kawamata, Yasuko; Matsumoto, Hideki; Sakai, Ryosei; Lang, Charles H.; Lynch, Christopher J.

    2013-01-01

    Branched-chain amino acids (BCAAs) are circulating nutrient signals for protein accretion, however, they increase in obesity and elevations appear to be prognostic of diabetes. To understand the mechanisms whereby obesity affects BCAAs and protein metabolism, we employed metabolomics and measured rates of [1-14C]-leucine metabolism, tissue-specific protein synthesis and branched-chain keto-acid (BCKA) dehydrogenase complex (BCKDC) activities. Male obese Zucker rats (11-weeks old) had increased body weight (BW, 53%), liver (107%) and fat (∼300%), but lower plantaris and gastrocnemius masses (−21–24%). Plasma BCAAs and BCKAs were elevated 45–69% and ∼100%, respectively, in obese rats. Processes facilitating these rises appeared to include increased dietary intake (23%), leucine (Leu) turnover and proteolysis [35% per g fat free mass (FFM), urinary markers of proteolysis: 3-methylhistidine (183%) and 4-hydroxyproline (766%)] and decreased BCKDC per g kidney, heart, gastrocnemius and liver (−47–66%). A process disposing of circulating BCAAs, protein synthesis, was increased 23–29% by obesity in whole-body (FFM corrected), gastrocnemius and liver. Despite the observed decreases in BCKDC activities per gm tissue, rates of whole-body Leu oxidation in obese rats were 22% and 59% higher normalized to BW and FFM, respectively. Consistently, urinary concentrations of eight BCAA catabolism-derived acylcarnitines were also elevated. The unexpected increase in BCAA oxidation may be due to a substrate effect in liver. Supporting this idea, BCKAs were elevated more in liver (193–418%) than plasma or muscle, and per g losses of hepatic BCKDC activities were completely offset by increased liver mass, in contrast to other tissues. In summary, our results indicate that plasma BCKAs may represent a more sensitive metabolic signature for obesity than BCAAs. Processes supporting elevated BCAA]BCKAs in the obese Zucker rat include increased dietary intake, Leu and

  2. Oxytocin and a C-terminal derivative (Z-prolyl-D-leucine) attenuate tolerance to and dependence on morphine and interact with dopaminergic neurotransmission in the mouse brain.

    PubMed

    Kovács, G L; Horváth, Z; Sarnyai, Z; Faludi, M; Telegdy, G

    1985-05-01

    The effects of oxytocin (OXT) and of dipeptides derived from the C-terminal portion of oxytocin (Z-prolyl-leucine and Z-prolyl-D-leucine) on the development of acute and chronic tolerance to, and dependence on morphine were tested in the mouse. Oxytocin and the dipeptides attenuated the development of acute and chronic tolerance to the antinociceptive effect of morphine and delayed the onset of the naloxone-precipitated withdrawal syndrome. Both oxytocin and Z-prolyl-D-leucine affected drug-induced behavioural responses related to dopamine (DA) in the brain. Thus, oxytocin potentiated the hypermotility induced by a large dose of apomorphine and decreased the supersensitivity of the DA receptors. Small doses of Z-prolyl-D-leucine inhibited the hypomotility elicited by a small dose of apomorphine and potentiated the hyperactivity induced by amphetamine. The data indicate that both oxytocin and Z-prolyl-D-leucine affect tolerance to and dependence on morphine. While oxytocin interacts mainly with postsynaptic DA-ergic neuronal elements, the dipeptide primarily affects DA-ergic neurotransmission at the presynaptic level. PMID:2991800

  3. Enhancement of energy expenditure following a single oral dose of flavan-3-ols associated with an increase in catecholamine secretion.

    PubMed

    Matsumura, Yusuke; Nakagawa, Yuta; Mikome, Katsuyuki; Yamamoto, Hiroki; Osakabe, Naomi

    2014-01-01

    Numerous clinical studies have reported that ingestion of chocolate reduces the risk of metabolic syndrome. However, the mechanisms by which this occurs remain unclear. In this murine study, the metabolic-enhancing activity of a 10 mg/kg mixture of flavan-3-ol fraction derived from cocoa (FL) was compared with the same single dose of (-)-epicatechin (EC). Resting energy expenditure (REE) was significantly increased in mice treated with the FL versus the group administered the distilled water vehicle (Cont) during periods of ad libitum feeding and fasting. Mice were euthanized under the effect of anesthesia 2, 5, and 20 hr after treatment with FL or Cont while subsequently fasting. The mRNA levels of the uncoupling protein-1 (UCP-1) and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) in brown adipose tissue (BAT) were significantly increased 2 hr after administration of FL. UCP-3 and PGC-1α in the gastrocnemius were significantly increased 2 and 5 hr after administration of the FL. The concentrations of phosphorylated AMP-activated protein kinase (AMPK) 1α were found to be significant in the gastrocnemius of mice 2 and 5 hr after ingesting FL. However, these changes were not observed following treatment with EC. Plasma was collected for measurement of catecholamine levels in other animals euthanized by decapitation 2 and 4 hr after their respective group treatment. Plasma adrenaline level was significantly elevated 2 hr after treatment with FL; however, this change was not observed following the administration of EC alone. The present results indicated that FL significantly enhanced systemic energy expenditure, as evidenced by an accompanying increase in the type of gene expression responsible for thermogenesis and lipolysis, whereas EC exhibited this less robustly or effectively. It was suggested the possible interaction between thermogenic and lipolytic effects and the increase in plasma catecholamine concentrations after

  4. Enhancement of Energy Expenditure following a Single Oral Dose of Flavan-3-Ols Associated with an Increase in Catecholamine Secretion

    PubMed Central

    Matsumura, Yusuke; Nakagawa, Yuta; Mikome, Katsuyuki; Yamamoto, Hiroki; Osakabe, Naomi

    2014-01-01

    Numerous clinical studies have reported that ingestion of chocolate reduces the risk of metabolic syndrome. However, the mechanisms by which this occurs remain unclear. In this murine study, the metabolic-enhancing activity of a 10 mg/kg mixture of flavan-3-ol fraction derived from cocoa (FL) was compared with the same single dose of (-)-epicatechin (EC). Resting energy expenditure (REE) was significantly increased in mice treated with the FL versus the group administered the distilled water vehicle (Cont) during periods of ad libitum feeding and fasting. Mice were euthanized under the effect of anesthesia 2, 5, and 20 hr after treatment with FL or Cont while subsequently fasting. The mRNA levels of the uncoupling protein-1 (UCP-1) and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) in brown adipose tissue (BAT) were significantly increased 2 hr after administration of FL. UCP-3 and PGC-1α in the gastrocnemius were significantly increased 2 and 5 hr after administration of the FL. The concentrations of phosphorylated AMP-activated protein kinase (AMPK) 1α were found to be significant in the gastrocnemius of mice 2 and 5 hr after ingesting FL. However, these changes were not observed following treatment with EC. Plasma was collected for measurement of catecholamine levels in other animals euthanized by decapitation 2 and 4 hr after their respective group treatment. Plasma adrenaline level was significantly elevated 2 hr after treatment with FL; however, this change was not observed following the administration of EC alone. The present results indicated that FL significantly enhanced systemic energy expenditure, as evidenced by an accompanying increase in the type of gene expression responsible for thermogenesis and lipolysis, whereas EC exhibited this less robustly or effectively. It was suggested the possible interaction between thermogenic and lipolytic effects and the increase in plasma catecholamine concentrations after

  5. Relations among arginine, citrulline, ornithine, and leucine kinetics in adult burn patients.

    PubMed

    Yu, Y M; Ryan, C M; Burke, J F; Tompkins, R G; Young, V R

    1995-11-01

    Plasma fluxes of arginine, citrulline, and leucine, and the rate of conversion of labeled citrulline to arginine (Qcit-->arg) were determined in nine severely burned patients (mean: 56% body surface burn area, mean 10 d postinjury) while they received total parenteral nutrition (TPN) including an L-amino acid mixture that supplied a generous amount of nitrogen (mean: 0.39 +/- 0.02 g.kg-1.d-1). Plasma fluxes were also studied in these patients during a basal state (low-dose intravenous glucose) by using a primed, 4-h constant intravenous tracer-infusion protocol. Stable-nuclide labeled tracers were L-[15N-15N-guanidino,5,5,2H2]arginine; L-[13C-ureido]citrulline; L-[1-13C]leucine; and NaH13CO3 (prime only), with blood and expired air samples drawn at intervals to determine isotopic abundance of arginine, citrulline, ornithine, and alpha-ketoisocaproate (KIC; for leucine) in plasma and 13CO2 in breath. Leucine kinetics (flux and disappearance into protein synthesis) confirmed the anticipated higher protein turnover in these burn patients compared with healthy control subjects. The plasma arginine fluxes were correspondingly higher in burn patients than in healthy control subjects. However, the citrulline flux and rate of conversion of citrulline to arginine were not higher than values obtained in our laboratories in healthy adult subjects. We hypothesize that the higher rates of arginine loss from the body after burn injury would need to be balanced by an appropriate exogenous intake of preformed arginine to maintain protein homeostasis and promote recovery from this catabolic condition. PMID:7572742

  6. Additive insulinogenic action of Opuntia ficus-indica cladode and fruit skin extract and leucine after exercise in healthy males

    PubMed Central

    2013-01-01

    Background Oral intake of a specific extract of Opuntia ficus-indica cladode and fruit skin (OpunDia™) (OFI) has been shown to increase serum insulin concentration while reducing blood glucose level for a given amount of glucose ingestion after an endurance exercise bout in healthy young volunteers. However, it is unknown whether OFI-induced insulin stimulation after exercise is of the same magnitude than the stimulation by other insulinogenic agents like leucine as well as whether OFI can interact with those agents. Therefore, the aims of the present study were: 1) to compare the degree of insulin stimulation by OFI with the effect of leucine administration; 2) to determine whether OFI and leucine have an additive action on insulin stimulation post-exercise. Methods Eleven subjects participated in a randomized double-blind cross-over study involving four experimental sessions. In each session the subjects successively underwent a 2-h oral glucose tolerance test (OGTT) after a 30-min cycling bout at ~70% VO2max. At t0 and t60 during the OGTT, subjects ingested 75 g glucose and capsules containing either 1) a placebo; 2) 1000 mg OFI; 3) 3 g leucine; 4) 1000 mg OFI + 3 g leucine. Blood samples were collected before and at 30-min intervals during the OGTT for determination of blood glucose and serum insulin. Results Whereas no effect of leucine was measured, OFI reduced blood glucose at t90 by ~7% and the area under the glucose curve by ~15% and increased serum insulin concentration at t90 by ~35% compared to placebo (P<0.05). From t60 to the end of the OGTT, serum insulin concentration was higher in OFI+leucine than in placebo which resulted in a higher area under the insulin curve (+40%, P<0.05). Conclusion Carbohydrate-induced insulin stimulation post-exercise can be further increased by the combination of OFI with leucine. OFI and leucine could be interesting ingredients to include together in recovery drinks to resynthesize muscle glycogen faster post

  7. Leucine-induced activation of translational initiation is partly regulated by the branched-chain {alpha}-keto acid dehydrogenase complex in C2C12 cells

    SciTech Connect

    Nakai, Naoya . E-mail: nakai@hss.osaka-u.ac.jp; Shimomura, Yoshiharu; Tamura, Tomohiro; Tamura, Noriko; Hamada, Koichiro; Kawano, Fuminori; Ohira, Yoshinobu

    2006-05-19

    Branched-chain amino acid leucine has been shown to activate the translational regulators through the mammalian target of rapamycin. However, the leucine's effects are self-limiting because leucine promotes its own disposal by an oxidative pathway. The irreversible and rate-limiting step in the leucine oxidation pathway is catalyzed by the branched-chain {alpha}-keto acid dehydrogenase (BCKDH) complex. The complex contains E1 ({alpha}2{beta}2), E2, and E3 subunits, and its activity is abolished by phosphorylation of the E1{alpha} subunit by BCKDH kinase. The relationship between the activity of BCKDH complex and leucine-mediated activation of the protein translation was investigated using the technique of RNA interference. The activity of BCKDH complex in C2C12 cell was modulated by transfection of small interfering RNA (siRNA) for BCKDH E2 subunit or BCKDH kinase. Transfection of siRNAs decreased the mRNA expression and protein amount of corresponding gene. Suppression of either E2 subunit or kinase produced opposite effects on the cell proliferation and the activation of translational regulators by leucine. Suppression of BCKDH kinase for 48 h resulted in decreasing cell proliferation. In contrast, E2 suppression led to increased amount of total cellular protein. The phosphorylation of p70 S6 kinase by leucine was increased in E2-siRNA transfected C2C12 cells, whereas the leucine's effect was diminished in kinase-siRNA transfected cells. These results suggest that the activation of the translational regulators by leucine was partly regulated by the activity of BCKDH complex.

  8. Increasing the Vegetable Intake Dose Is Associated with a Rise in Plasma Carotenoids without Modifying Oxidative Stress or Inflammation in Overweight or Obese Postmenopausal Women123

    PubMed Central

    Crane, Tracy E.; Kubota, Chieri; West, Julie L.; Kroggel, Mark A.; Wertheim, Betsy C.; Thomson, Cynthia A.

    2011-01-01

    The optimal amount of vegetable consumption required to reduce chronic disease risk is widely debated. Intervention trials evaluating biological activity of vegetables at various doses are limited. We conducted a 3-dose, crossover feeding trial to test the hypothesis that vegetable intake is associated in a dose-dependent manner with increased plasma carotenoids and subsequently reduced oxidative stress and inflammation in 49 overweight, postmenopausal women. Participants were assigned in random order to 2 (130 g), 5 (287 g), and 10 (614 g) daily servings of fresh, greenhouse-grown vegetables for 3-wk intervals with a 4-wk washout period between treatments. Plasma total carotenoids significantly increased from 1.63 to 2.07 μmol/L with a dose of 2 vegetable servings, from 1.49 to 2.84 μmol/L with a dose of 5 vegetable servings, and from 1.40 to 4.42 μmol/L with a dose of 10 vegetable servings (pre-post paired ttests, all P < 0.001). The change during each feeding period increased with each dose level (P < 0.001). Urine concentrations of 8-isoprostane F2α, hexanoyl lysine, and serum high sensitivity C-reactive protein were not affected by any administered vegetable dose. In this variable-dose vegetable study, a dose-response for plasma carotenoids was demonstrated without significant change in oxidative stress and inflammation in overweight, postmenopausal women. PMID:21865569

  9. Response of CFU-GM to increasing doses of rhGM-CSF in patients with aplastic anemia.

    PubMed

    Bacigalupo, A; Piaggio, G; Figari, O; Tong, J; Sogno, G; Tedone, E; Sette, A; Ratto, M R; Caciagli, P; Badolati, G

    1991-09-01

    The aim of this study was to test whether large amounts of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) are capable of promoting the growth of hemopoietic progenitors from patients with marrow failure. For this purpose 0.1, 100, 1000, 10,000 and 20,000 ng/ml of rhGM-CSF were added to 10(5) light-density (adherent cell-depleted) bone marrow cells from 9 normal controls and from 52 patients with aplastic anemia, 25 cases of which were transfusion-dependent (Tx-D) aplastic anemia (AA) and 27 of which were transfusion-independent (Tx-I) aplastic anemia (AA). A dose-dependent increase of granulocyte-macrophage colony-forming units (CFU-GM) was observed in healthy donors, from 81 to 247 colonies at 0.1 and 1000 ng/ml of rhGM-CSF, with a plateau thereafter. Tx-I AA patients showed the best increase of CFU-GM in response to colony-stimulating factor, from 0.1 to 32.7 mean colonies at 0.1 and 20,000 ng/ml of rhGM-CSF, and the increment was greater when compared to controls. The ratio of CFU-GM grown from these patients and controls was 1:810 at 0.1 ng/ml of rhGM-CSF and 1:7.9 at 20,000 ng/ml. Eleven patients were studied at diagnosis; there was no in vitro response to rhGM-CSF (0 and 1.8 mean colonies/10(5) cells at 0.1 and 10,000 ng/ml). Overall, Tx-D AA patients showed minimal increments of CFU-GM growth at very high doses of rhGM-CSF. Two suggestions come from this study: 1) maturation of CFU-GM from recovering AA patients appears to require larger doses of GM-CSF than normal controls, and 2) very high doses of rhGM-CSF have little or no effect on CFU-GM growth in AA patients. This may be relevant for clinical studies designed to improve hemopoiesis in patients with marrow failure. PMID:1868897

  10. Perineural Invasion Predicts Increased Recurrence, Metastasis, and Death From Prostate Cancer Following Treatment With Dose-Escalated Radiation Therapy

    SciTech Connect

    Feng, Felix Y.; Qian Yushen; Stenmark, Matthew H.; Halverson, Schuyler; Blas, Kevin; Vance, Sean; Sandler, Howard M.; Hamstra, Daniel A.

    2011-11-15

    Purpose: To assess the prognostic value of perineural invasion (PNI) for patients treated with dose-escalated external-beam radiation therapy for prostate cancer. Methods and Materials: Outcomes were analyzed for 651 men treated for prostate cancer with EBRT to a minimum dose {>=}75 Gy. We assessed the impact of PNI as well as pretreatment and treatment-related factors on freedom from biochemical failure (FFBF), freedom from metastasis (FFM), cause-specific survival (CSS), and overall survival. Results: PNI was present in 34% of specimens at biopsy and was significantly associated with higher Gleason score (GS), T stage, and prostate-specific antigen level. On univariate and multivariate analysis, the presence of PNI was associated with worse FFBF (hazard ratio = 1.7, p <0.006), FFM (hazard ratio = 1.8, p <0.03), and CSS (HR = 1.4, p <0.05) compared with absence of PNI; there was no difference in overall survival. Seven-year rates of FFBF, FFM, and CCS were 64% vs. 80%, 84% vs. 92%, and 91% vs. 95% for those patients with and without PNI, respectively. On recursive partitioning analysis, PNI predicted for worse FFM and CSS in patients with GS 8-10, with FFM of 67% vs. 89% (p <0.02), and CSS of 69% vs. 91%, (p <0.04) at 7 years for those with and without PNI, respectively. Conclusions: The presence of PNI in the prostate biopsy predicts worse clinical outcome for patients treated with dose-escalated external-beam radiation therapy. Particularly in patients with GS 8-10 disease, the presence of PNI suggests an increased risk of metastasis and prostate cancer death.

  11. Leucine improves glucose and lipid status in offspring from obese dams, dependent on diet type, but not caloric intake.

    PubMed

    Chen, H; Simar, D; Ting, J H Y; Erkelens, J R S; Morris, M J

    2012-10-01

    Previously, we showed that offspring from obese rat dams were hyperphagic, with increased adiposity, hyperlipidaemia and glucose intolerance associated with increased orexigenic neuropeptide expression after fasting. Mammalian target of rapamycin (mTOR) can inhibit food intake through a hypothalamic action. As we previously showed that maternal obesity down-regulated hypothalamic mTOR, in the present study, we hypothesised that dietary leucine supplementation would activate hypothalamic mTOR to reduce food intake, thus limiting metabolic disorders in offspring from obese dams, regardless of postweaning diet. Obesity was induced in Sprague-Dawley females by high-fat diet (HFD) for 5 weeks before mating, throughout gestation and lactation. Male pups from HFD-fed mothers were weaned onto chow or HFD; within each dietary group, half were supplied with leucine via drinking water (1.5%) versus water control for 10 weeks. Those from chow-fed mothers were fed chow and water. Maternal obesity led to increased adiposity in chow-fed offspring. Postweaning HFD consumption exaggerated adiposity, hyperglycaemia, hyperinsulinaemia and hyperlipidaemia. Supplementation with leucine doubled leucine intake and increased hypothalamic mTOR activation; however, appetite regulation was not affected. A reduction in blood lipid levels was observed in offspring regardless of diet, as well as improved glucose tolerance in HFD-fed rats. In HFD-fed rats, up-regulated carnitine palmitoyl-transferase-1 and peroxisome-proliferator-activated receptor-γ coactivator-1α in muscle and glucose transporter 4 in fat suggested that leucine improved peripheral fat oxidation and glucose transport. Leucine is able to improve peripheral glucose and lipid metabolism independent of appetite and weight regulation, suggesting its potential application in the management of metabolic disorders. PMID:22612562

  12. Increased serum bile acid concentration following low-dose chronic administration of thioacetamide in rats, as evidenced by metabolomic analysis.

    PubMed

    Jeong, Eun Sook; Kim, Gabin; Shin, Ho Jung; Park, Se-Myo; Oh, Jung-Hwa; Kim, Yong-Bum; Moon, Kyoung-Sik; Choi, Hyung-Kyoon; Jeong, Jayoung; Shin, Jae-Gook; Kim, Dong Hyun

    2015-10-15

    A liquid chromatography/time-of-flight mass spectrometry (LC/TOF-MS)-based metabolomics approach was employed to identify endogenous metabolites as potential biomarkers for thioacetamide (TAA)-induced liver injury. TAA (10 and 30mg/kg), a well-known hepatotoxic agent, was administered daily to male Sprague-Dawley (SD) rats for 28days. We then conducted untargeted analyses of endogenous serum and liver metabolites. Partial least squares discriminant analysis (PLS-DA) was performed on serum and liver samples to evaluate metabolites associated with TAA-induced perturbation. TAA administration resulted in altered levels of bile acids, acyl carnitines, and phospholipids in serum and in the liver. We subsequently demonstrated and confirmed the occurrence of compromised bile acid homeostasis. TAA treatment significantly increased serum levels of conjugated bile acids in a dose-dependent manner, which correlated well with toxicity. However, hepatic levels of these metabolites were not substantially changed. Gene expression profiling showed that the hepatic mRNA levels of Ntcp, Bsep, and Oatp1b2 were significantly suppressed, whereas those of basolateral Mrp3 and Mrp4 were increased. Decreased levels of Ntcp, Oatp1b2, and Ostα proteins in the liver were confirmed by western blot analysis. These results suggest that serum bile acids might be increased due to the inhibition of bile acid enterohepatic circulation rather than increased endogenous bile acid synthesis. Moreover, serum bile acids are a good indicator of TAA-induced hepatotoxicity. PMID:26222700

  13. Fetoplacental deamination and decarboxylation of leucine

    SciTech Connect

    Loy, G.L.; Quick, A.N. Jr.; Hay, W.W. Jr.; Meschia, G.; Battaglia, F.C.; Fennessey, P.V. )

    1990-10-01

    Fetal and placental metabolism of leucine (Leu) and ketoisocaproic acid (KIC) were studied in seven fetal lambs at 132 +/- 1.3-days gestation. Fetal infusions of (1-13C)Leu, (1-14C)Leu, and antipyrine were carried out for 4 h. Uterine and umbilical blood flows were measured using the antipyrine steady-state diffusion technique. Leu and KIC concentrations, (14C)Leu-specific activities, 14CO2, (13C)Leu, and (13C)KIC enrichment (mole percent enrichment) were measured in the maternal artery, uterine vein, and umbilical artery and vein to calculate net fluxes of tracee and tracer molecules between fetus and placenta and between the uteroplacenta and the maternal circulation. There were net Leu and KIC fluxes into the fetus from the placenta with the KIC flux equal to approximately 19% of the combined Leu plus KIC flux. In addition, there was a net KIC flux into the uterine circulation. The fraction of infused tracer Leu escaping the placenta into the mother was small (approximately 6%). By contrast, there was a rapid exchange of tracer Leu carbon between placenta and fetus resulting in a significant flux of labeled KIC from placenta to fetus. Approximately 20% of the infused tracer carbon was converted to CO2 within the fetus. This rate of conversion was greater than 80% of the total fetoplacental conversion rate and significantly higher than the flux of KIC tracer carbon from placenta to fetus. Fetal KIC decarboxylation rate, calculated from the fetal KIC enrichment data, was 2.83 +/- 0.40 mumol.min-1.kg fetus-1 and approximately 60% of the combined net Leu and KIC flux into the fetus from the placenta.

  14. One calcitriol dose transiently increases Helios+ FoxP3+ T cells and ameliorates autoimmune demyelinating disease.

    PubMed

    Nashold, Faye E; Nelson, Corwin D; Brown, Lauren M; Hayes, Colleen E

    2013-10-15

    Multiple sclerosis (MS) is an incurable inflammatory demyelinating disease. We investigated one calcitriol dose plus vitamin D3 (calcitriol/+D) as a demyelinating disease treatment in experimental autoimmune encephalomyelitis (EAE). Evidence that calcitriol-vitamin D receptor pathway deficits may promote MS, and data showing calcitriol enhancement of autoimmune T cell apoptosis provided the rationale. Whereas vitamin D3 alone was ineffective, calcitriol/+D transiently increased central nervous system (CNS) Helios(+)FoxP3(+) T cells and sustainably decreased CNS T cells, pathology, and neurological deficits in mice with EAE. Calcitriol/+D, which was more effective than methylprednisolone, has potential for reversing inflammatory demyelinating disease safely and cost-effectively. PMID:23968560

  15. Mitochondrial and sarcoplasmic proteins, but not myosin heavy chain, are sensitive to leucine supplementation in old rat skeletal muscle.

    PubMed

    Guillet, Christelle; Zangarelli, Aude; Mishellany, Anne; Rousset, Paulette; Sornet, Claire; Dardevet, Dominique; Boirie, Yves

    2004-05-01

    Leucine has a major anabolic impact on muscle protein synthesis in young as in old animals. However, myosin heavy chain (MHC), sarcoplasmic and mitochondrial proteins may differently respond to anabolic factors, especially during aging. To test this hypothesis, fractional synthesis rates (FSR) of the three muscle protein fractions were measured using a flooding dose of [1-(13)C] phenylalanine, in gastrocnemius muscle of adult (8 months) and old (22 months) rats, either in postabsorptive state (PA), or 90-120 min after ingestion of a alanine-supplemented meal (PP+A) or a leucine-supplemented meal (PP+L). In adult and old rats, in comparison with PA, leucine stimulated mitochondrial (adult: 0.260+/-0.011 vs 0.238+/-0.012%h(-1); old: 0.289+/-0.010 vs 0.250+/-0.010%h(-1); PP+L vs PA, P<0.05) and sarcoplasmic (adult: 0.182+/-0.011 vs 0.143+/-0.006%h(-1); old: 0.195+/-0.010 vs 0.149+/-0.008%h(-1); PP+L vs PA, P<0.05) protein FSR, but not MHC synthesis in old rats (0.101+/-0.009 vs 0.137+/-0.018%h(-1); PP+L vs PA, P=NS). In conclusion, synthesis of specific muscle protein is activated by leucine supplementation, but MHC may be less sensitive to anabolic factors with aging. PMID:15130669

  16. Single-Dose Local Simvastatin Injection Improves Implant Fixation via Increased Angiogenesis and Bone Formation in an Ovariectomized Rat Model

    PubMed Central

    Tan, Jie; Yang, Ning; Fu, Xin; Cui, Yueyi; Guo, Qi; Ma, Teng; Yin, Xiaoxue; Leng, Huijie; Song, Chunli

    2015-01-01

    Background Statins have been reported to promote bone formation. However, taken orally, their bioavailability is low to the bones. Implant therapies require a local repair response, topical application of osteoinductive agents, or biomaterials that promote implant fixation. Material/Methods The present study evaluated the effect of a single local injection of simvastatin on screw fixation in an ovariectomized rat model of osteoporosis. Results Dual-energy X-ray absorptiometry, micro-computed tomography, histology, and biomechanical tests revealed that 5 and 10 mg simvastatin significantly improved bone mineral density by 18.2% and 22.4%, respectively (P<0.05); increased bone volume fraction by 51.0% and 57.9%, trabecular thickness by 16.4% and 18.9%, trabeculae number by 112.0% and 107.1%, and percentage of osseointegration by 115.7% and 126.3%; and decreased trabeculae separation by 34.1% and 36.6%, respectively (all P<0.01). Bone mineral apposition rate was significantly increased (P<0.01). Furthermore, implant fixation was significantly increased (P<0.05), and bone morphogenetic protein 2 (BMP2) expression was markedly increased. Local injection of a single dose of simvastatin also promoted angiogenesis. Vessel number, volume, thickness, surface area, and vascular volume per tissue volume were significantly increased (all P<0.01). Vascular endothelial growth factor (VEGF), VEGF receptor-2, von Willebrand factor, and platelet endothelial cell adhesion molecule-1 expression were enhanced. Conclusions A single local injection of simvastatin significantly increased bone formation, promoted osseointegration, and enhanced implant fixation in ovariectomized rats. The underlying mechanism appears to involve enhanced BMP2 expression and angiogenesis in the target bone. PMID:25982481

  17. Leukemia patient-derived lymphoblastoid cell lines exhibit increased induction of leukemia-associated transcripts following high-dose irradiation.

    PubMed

    Spencer, A; Granter, N

    1999-09-01

    Improvement in diagnostic cytogenetic techniques has led to the recognition of an increasing number of leukemia-associated chromosomal translocations and inversions. These genetic lesions frequently are associated with the disruption of putative transcription factors and the production of hybrid transcripts that are implicated in leukemogenesis. Epidemiologic evidence suggests that some, but not all, individuals with a history of gamma-irradiation exposure are at increased risk of developing chronic myeloid leukemia (CML). CML is characterized by the Philadelphia chromosome and transcription of the resulting hybrid BCR-ABL gene. Utilizing the leukemia-associated BCR-ABL p210 transcript as a marker, we sought differences in the induction of illegitimate genetic recombination following high-dose gamma-irradiation of karyotypically normal lymphoblastoid cell lines (LCL) derived from individuals with and without a history of myeloid leukemias. Six LCL [4 leukemia patient derived [2 acute myeloid leukemia and 2 CML] and 2 from normal individuals were analyzed with reverse transcriptase polymerase chain reaction for BCR-ABL under stringent conditions following exposure to 0, 50, or 100 Gy of LET gamma-irradiation delivered via a Varian linear accelerator at 4 MV. Transcripts identical to disease-associated b2a2 and b3a2 transcripts were detected both spontaneously (background illegitimate genetic recombination) and following gamma-irradiation. Background BCR-ABL positivity was demonstrable in 4 of the 6 LCL, with no significant difference in detection between leukemic- and nonleukemic-derived LCL. Overall, increasing gamma-irradiation dose resulted in an increased frequency of BCR-ABL transcript detection (0 Gy vs 50 Gy vs 100 Gy,p = 0.0023, Chi-square test). Within the leukemic- but not the nonleukemic-derived LCL there was significantly greater BCR-ABL positivity after gamma-irradiation compared to unirradiated equivalents. Furthermore, the BCR-ABL positivity of both

  18. Impact of prolonged leucine supplementation on protein synthesis and lean growth in neonatal pigs.

    PubMed

    Columbus, Daniel A; Steinhoff-Wagner, Julia; Suryawan, Agus; Nguyen, Hanh V; Hernandez-Garcia, Adriana; Fiorotto, Marta L; Davis, Teresa A

    2015-09-15

    Most low-birth weight infants experience extrauterine growth failure due to reduced nutrient intake as a result of feeding intolerance. The objective of this study was to determine whether prolonged enteral leucine supplementation improves lean growth in neonatal pigs fed a restricted protein diet. Neonatal pigs (n = 14-16/diet, 5 days old, 1.8 ± 0.3 kg) were fed by gastric catheter a whey-based milk replacement diet with either a high protein (HP) or restricted protein (RP) content or RP supplemented with leucine to the same level as in the HP diet (RPL). Pigs were fed 40 ml·kg body wt(-1)·meal(-1) every 4 h for 21 days. Feeding the HP diet resulted in greater total body weight and lean body mass compared with RP-fed pigs (P < 0.05). Masses of the longissimus dorsi muscle, heart, and kidneys were greater in the HP- than RP-fed pigs (P < 0.05). Body weight, lean body mass, and masses of the longissimus dorsi, heart, and kidneys in pigs fed the RPL diet were intermediate to RP- and HP-fed pigs. Protein synthesis and mTOR signaling were increased in all muscles with feeding (P < 0.05); leucine supplementation increased mTOR signaling and protein synthesis rate in the longissimus dorsi (P < 0.05). There was no effect of diet on indices of protein degradation signaling in any tissue (P > 0.05). Thus, when protein intake is chronically restricted, the capacity for leucine supplementation to enhance muscle protein accretion in neonatal pigs that are meal-fed milk protein-based diets is limited. PMID:26374843

  19. Perinatal exposure to low-dose DE-71 increases serum thyroid hormones and gonadal osteopontin gene expression

    PubMed Central

    Blake, Charles A; McCoy, George L; Hui, Yvonne Y; LaVoie, Holly A

    2014-01-01

    Polybrominated diphenyl ethers (PBDEs) are flame retardants that have been widely used in manufacturing. They are major household and environmental contaminants that bioaccumulate. Humans are exposed primarily through dust inhalation and dietary ingestion of animal products. In animal studies, high doses of penta-brominated diphenyl ethers (penta-BDEs) in the mg/kg body weight (BW) range negatively impact brain development, behavior, memory, circulating thyroid hormone concentrations, the reproductive system and bone development. We investigated the effects of ingestion of a relatively low dose of the penta-BDE mixture DE-71 by pregnant and lactating rats on reproductive and thyroid parameters of the F1 offspring. F0 mothers received 60 μg/kg BW of DE-71 or vehicle daily by gavage from Day 1.5 of pregnancy through lactation (except the day of parturition). F1 pups were sacrificed at 21 d of age or outbred at approximately 80 d of age. Bred F1 females were sacrificed at Day 14.5 of pregnancy or at five months of age. Bred F1 males were sacrificed at five months of age. DE-71 treatment of the mothers affected the F1 females as evidenced by lower body weights at 80 d and five months of age, elevated serum T3 and T4 concentrations at Day 14.5 of pregnancy and increased thyroid gland weight and ovarian osteopontin mRNA at five months of age. Perinatal DE-71 exposure also increased testicular osteopontin mRNA in 21-day-old F1 males. Utilizing a granulosa cell in vitro model, we demonstrated that DE-71 activated the rat osteopontin gene promoter. Our results are the first to demonstrate that PBDEs increase rodent circulating T3 and T4 concentrations and gonadal osteopontin mRNA, and activate the osteopontin gene promoter. These changes may have clinical implications as others have shown associations between human exposure to PBDEs and subclinical hyperthyroidism, and overexpression of ovarian osteopontin has been associated with ovarian cancer. PMID:21367881

  20. Low-Dose Bisphenol A and Estrogen Increase Ventricular Arrhythmias Following Ischemia-Reperfusion in Female Rat Hearts

    PubMed Central

    Yan, Sujuan; Song, Weizhong; Chen, Yamei; Hong, Kui; Rubinstein, Jack; Wang, Hong-Sheng

    2013-01-01

    Bisphenol A (BPA) is an environmental estrogenic endocrine disruptor that may have adverse health impacts on a range of tissue/systems. In previous studies, we reported that BPA rapidly promoted arrhythmias in female rodent hearts through alteration of myocyte calcium handling. In the present study we investigated the acute effects of BPA on ventricular arrhythmias and infarction following ischemia-reperfusion in rat hearts. Rat hearts were subjected to 20 minutes of global ischemia followed by reperfusion. In female, but not male hearts, acute exposure to 1 nM BPA, either alone or combined with 1 nM 17β-estradiol (E2), during reperfusion resulted in a marked increase in the duration of sustained ventricular arrhythmias. BPA plus E2 increased the duration ventricular fibrillation, and the duration of VF as a fraction of total duration of sustained ventricular arrhythmia. The pro-arrhythmic effects of estrogens were abolished by MPP combined with PHTPP, suggesting the involvements of both ERα and ERβ signaling. In contrast to their pro-arrhythmic effects, BPA and E2 reduced infarction size, agreeing with previously described protective effect of estrogen against cardiac infarction. In conclusion, rapid exposure to low dose BPA, particularly when combined with E2, exacerbates ventricular arrhythmia following IR injury in female rat hearts. PMID:23429042

  1. Atrazine Does Not Induce Pica Behavior at Doses that Increase Hypothalamic-Pituitary-Adrenal Axis Activation and Cause Conditioned Taste Avoidance.

    EPA Science Inventory

    Previous work has shown that a single oral administration of atrazine (ATR), a chlorotriazine herbicide, induces dose-dependent increases in plasma adrenocorticotropic hormone (ACTH), serum corticosterone (CORT) and progesterone. The mechanism for these effects is unknown. To tes...

  2. Acute effects of enteral leucine supplementation of a low protein diet on muscle protein synthesis in neonatal pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Protein synthesis and eukaryotic initiation factor (eIF) activation are increased in skeletal muscle of neonatal pigs parenterally infused with insulin and amino acids (AA), particularly leucine. We hypothesized that enteral Leu supplementation of a low protein diets in neonatal pigs will acutely in...

  3. 250 mSv: temporary increase in the emergency exposure dose limit in response to the TEPCO Fukushima Daiichi NPP accident and its decision making process.

    PubMed

    Yasui, Shojiro

    2015-01-01

    The Great East Japan Earthquake on March 11, 2011, led to an accident at the Fukushima Daiichi Nuclear Power Plant of the Tokyo Electric Power Company (TEPCO). In response to this accident, on March 14, 2011, the Ministry of Health, Labour, and Welfare (MHLW) of Japan enforced an ordinance that temporarily increased the radiation exposure dose limit allowed to 250 mSv during the emergency. This article explains the processes of a) temporarily increasing emergency dose limits, b) controlling for the combined emergency and normal exposure doses, and c) reducing the limit back to 100 mSv. Major issues addressed when deliberating the reduction of the emergency limits includes the following: a) political initiative, b) a phased reduction of dose limits, and c) transitional measures for workers who were exposed to more than 100 mSv. This article also identifies key challenges that need further deliberation to be resolved. These include: a) establishing a pre-defined protocol for applying pre-accident emergency dose limits and/or amending post-accident limits; b) designating the conditions in which to apply or amend emergency dose limits; c) selecting methods of radiation control for individuals who are exposed to more than the normal exposure dose limit during emergency work; and d) designating the conditions under which to terminate or reduce emergency dose limits after the accident. PMID:25436995

  4. Low-dose testosterone protects against renal ischemia-reperfusion injury by increasing renal IL-10-to-TNF-α ratio and attenuating T-cell infiltration.

    PubMed

    Patil, Chetan N; Wallace, Kedra; LaMarca, Babbette D; Moulana, Mohadetheh; Lopez-Ruiz, Arnaldo; Soljancic, Andrea; Juncos, Luis A; Grande, Joseph P; Reckelhoff, Jane F

    2016-08-01

    Renal ischemia-reperfusion (I/R) in male rats causes reductions in plasma testosterone, and infusion of testosterone 3 h postreperfusion is protective. We tested the hypotheses that acute high doses of testosterone promote renal injury after I/R, and that acute low-dose testosterone is protective by the following: 1) increasing renal IL-10 and reducing TNF-α; 2) its effects on nitric oxide; and 3) reducing intrarenal T-cell infiltration. Rats were subjected to renal I/R, followed by intravenous infusion of vehicle or testosterone (20, 50, or 100 μg/kg) 3 h postreperfusion. Low-dose testosterone (20 μg/kg) reduced plasma creatinine, increased nitrate/nitrite excretion, increased intrarenal IL-10, and reduced intrarenal TNF-α, whereas 50 μg/kg testosterone failed to reduce plasma creatinine, increased IL-10, but failed to reduce TNF-α. A higher dose of testosterone (100 mg/kg) not only failed to reduce plasma creatinine, but significantly increased both IL-10 and TNF-α compared with other groups. Low-dose nitro-l-arginine methyl ester (1 mg·kg(-1)·day(-1)), given 2 days before I/R, prevented low-dose testosterone (20 μg/kg) from protecting against I/R injury, and was associated with lack of increase in intrarenal IL-10. Intrarenal CD4(+) and CD8(+) T cells were significantly increased with I/R, but were attenuated with low-dose testosterone, as were effector T helper 17 cells. The present studies suggest that acute, low-dose testosterone is protective against I/R AKI in males due to its effects on inflammation by reducing renal T-cell infiltration and by shifting the balance to favor anti-inflammatory cytokine production rather than proinflammatory cytokines. PMID:27252490

  5. MicroRNA-27a is induced by leucine and contributes to leucine-induced proliferation promotion in C2C12 cells.

    PubMed

    Chen, Xiaoling; Huang, Zhiqing; Chen, Daiwen; Yang, Ting; Liu, Guangmang

    2013-01-01

    Leucine, a branched chain amino acid, is well known to stimulate protein synthesis in skeletal muscle. However, the role of leucine in myoblast proliferation remains unclear. In this study, we found that leucine could promote proliferation of C2C12 cells. Moreover, expressions of miR-27a and myostatin (a bona fide target of miR-27a) were upregulated and downregulated, respectively, following leucine treatment. We also found that miR-27a loss-of-function by transfection of a miR-27a inhibitor suppressed the promotion of myoblast proliferation caused by leucine. Our results suggest that miR-27a is induced by leucine and contributes to leucine-induced proliferation promotion of myoblast. PMID:23880856

  6. Has the sensitivity of soybean cultivars to ozone pollution increased with time? An analysis of published dose-response data.

    PubMed

    Osborne, Stephanie A; Mills, Gina; Hayes, Felicity; Ainsworth, Elizabeth A; Büker, Patrick; Emberson, Lisa

    2016-09-01

    The rising trend in concentrations of ground-level ozone (O3 ) - a common air pollutant and phytotoxin - currently being experienced in some world regions represents a threat to agricultural yield. Soybean (Glycine max (L.) Merr.) is an O3 -sensitive crop species and is experiencing increasing global demand as a dietary protein source and constituent of livestock feed. In this study, we collate O3 exposure-yield data for 49 soybean cultivars, from 28 experimental studies published between 1982 and 2014, to produce an updated dose-response function for soybean. Different cultivars were seen to vary considerably in their sensitivity to O3 , with estimated yield loss due to O3 ranging from 13.3% for the least sensitive cultivar to 37.9% for the most sensitive, at a 7-h mean O3 concentration (M7) of 55 ppb - a level frequently observed in regions of the USA, India and China in recent years. The year of cultivar release, country of data collection and type of O3 exposure used were all important explanatory variables in a multivariate regression model describing soybean yield response to O3 . The data show that the O3 sensitivity of soybean cultivars increased by an average of 32.5% between 1960 and 2000, suggesting that selective breeding strategies targeting high yield and high stomatal conductance may have inadvertently selected for greater O3 sensitivity over time. Higher sensitivity was observed in data from India and China compared to the USA, although it is difficult to determine whether this effect is the result of differential cultivar physiology, or related to local environmental factors such as co-occurring pollutants. Gaining further understanding of the underlying mechanisms that govern the sensitivity of soybean cultivars to O3 will be important in shaping future strategies for breeding O3 -tolerant cultivars. PMID:27082950

  7. Phosphate depletion impairs leucine-induced insulin secretion.

    PubMed

    Oh, H Y; Fadda, G Z; Smogorzewski, M; Liou, H H; Massry, S G

    1994-11-01

    Phosphate depletion (PD) in vivo causes a sundry of abnormalities in pancreatic islets including a rise in cytosolic calcium, low ATP content, reduced Ca2+ ATPase and Na(+)-K+ ATPase activity, and impaired insulin secretion in response to glucose or potassium. L-Leucine is a strong secretagogue that triggers insulin secretion by deamination to alpha-ketoisocaproic acid (KIC) and the subsequent metabolism of the latter to ATP and by the activation of glutamate dehydrogenase (GLDH), which acts on glutamate to generate alpha-ketoglutarate, the metabolism of which results in ATP production. The generation of ATP triggers events that lead to insulin secretion. It is not known whether PD impairs leucine-induced insulin secretion, and the cellular derangements that are involved in such an abnormality are not defined. These issues were studied in PD rats and in pair-weighed normal animals as controls. D-Leucine uptake by islets from PD rats is normal, but both leucine- and KIC-induced insulin secretions are impaired and the activity of branched-chain keto acid dehydrogenase, which facilitates the metabolism of KIC, is reduced. Both leucine and 2-aminobicyclo (2-2-1) haptene failed to stimulate GLDH and to augment the generation of alpha-ketoglutarate in the islets of PD rats. Also, the concentration of basal alpha-ketoglutarate was significantly higher in the islets of PD rats, suggesting that its metabolism is impaired. In addition, the activity of glutaminase is significantly reduced, an abnormality that would result in decreased production of glutamate, the substrate for GLDH. The data show that PD impairs leucine-induced insulin secretion.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7873737

  8. Analysis of the effects of increasing doses of ionizing radiation to the exteriorized rat ovary on follicular development, atresia, and serum gonadotropin levels

    SciTech Connect

    Jarrell, J.; YoungLai, E.V.; Barr, R.; O'Connell, G.; Belbeck, L.; McMahon, A.

    1986-02-01

    There is increasing interest in the effects of environmental and therapeutic agents on the reproductive system, in particular, the ovary. To study the effects of controlled doses of ionizing radiation to the ovary, Sprague-Dawley rats had their ovaries exteriorized and subjected to increasing doses of radiation. There was a significant increase in ovarian follicular atresia, a significant increase in serum follicle-stimulating hormone levels, but no change in serum luteinizing hormone levels. This experimental protocol may facilitate the testing putative radioprotectants.

  9. Meta-analysis of comparative efficacy of increasing dose of Atorvastatin versus Rosuvastatin versus Simvastatin on lowering levels of atherogenic lipids (from VOYAGER).

    PubMed

    Nicholls, Stephen J; Brandrup-Wognsen, Gunnar; Palmer, Mike; Barter, Philip J

    2010-01-01

    Statins are the most commonly prescribed agents for lowering levels of low-density lipoprotein (LDL) cholesterol. Although dose-dependent reductions in levels of atherogenic lipids are observed with all statins, the impact of increasing dose has not been fully elucidated. An individual patient data pooled analysis was performed of 32,258 patients in studies comparing the efficacy of rosuvastatin with that of atorvastatin or simvastatin. The impact of increasing dose on lowering LDL cholesterol, triglycerides, non-high-density lipoprotein (HDL) cholesterol, and apolipoprotein B was investigated. Doubling the dose of each statin was accompanied by a 4% to 7% greater degree of lowering of all atherogenic lipids. A stronger correlation was observed between changes in LDL cholesterol and non-HDL cholesterol (r = 0.92, p <0.001) or apolipoprotein B (r = 0.76, p <0.001) than triglycerides (r = 0.14, p <0.001). On multivariate analysis, baseline lipid level (p <0.0001) and increasing statin dose (p <0.0001) were strong predictors of achieving treatment goals in high-risk patients. Increasing age was a strong independent predictor of achieving goal for all atherogenic lipids (p <0.0001). Achieving LDL cholesterol goals was also more likely in women (p <0.0001), patients with diabetes (p <0.0001), and patients without atherosclerotic disease (p = 0.0002). In contrast, normal triglyceride levels were more often observed in men (p <0.0001) and patients without diabetes mellitus (p = 0.03). In conclusion, doubling statin dose was associated with greater lowering of LDL cholesterol by 4% to 6% and non-HDL cholesterol by 3% to 6%. Greater lipid goal achievement with increasing dose supports the use of high-dose statin therapy for more effective cardiovascular prevention. PMID:20102893

  10. Addition of a third field significantly increases dose to the brachial plexus for patients undergoing tangential whole-breast therapy after lumpectomy

    SciTech Connect

    Stanic, Sinisa; Mathai, Mathew; Mayadev, Jyoti S.; Do, Ly V.; Purdy, James A.; Chen, Allen M.

    2012-07-01

    Our goal was to evaluate brachial plexus (BP) dose with and without the use of supraclavicular (SCL) irradiation in patients undergoing breast-conserving therapy with whole-breast radiation therapy (RT) after lumpectomy. Using the standardized Radiation Therapy Oncology Group (RTOG)-endorsed guidelines delineation, we contoured the BP for 10 postlumpectomy breast cancer patients. The radiation dose to the whole breast was 50.4 Gy using tangential fields in 1.8-Gy fractions, followed by a conedown to the operative bed using electrons (10 Gy). The prescription dose to the SCL field was 50.4 Gy, delivered to 3-cm depth. The mean BP volume was 14.5 {+-} 1.5 cm{sup 3}. With tangential fields alone, the median mean dose to the BP was 0.57 Gy, the median maximum dose was 1.93 Gy, and the irradiated volume of the BP receiving 40, 45, and 50 Gy was 0%. When the third (SCL field) was added, the dose to the BP was significantly increased (P = .01): the median mean dose to the BP was 40.60 Gy, and the median maximum dose was 52.22 Gy. With 3-field RT, the median irradiated volume of the BP receiving 40, 45, and 50 Gy was 83.5%, 68.5%, and 24.6%, respectively. The addition of the SCL field significantly increases dose to the BP. The possibility of increasing the risk of BP morbidity should be considered in the context of clinical decision making.

  11. Leucine disposal rate for assessment of amino acid metabolism in maintenance hemodialysis patients

    PubMed Central

    Denny, Gerald B.; Deger, Serpil M.; Chen, Guanhua; Bian, Aihua; Sha, Feng; Booker, Cindy; Kesler, Jaclyn T.; David, Sthuthi; Ellis, Charles D.; Ikizler, T. Alp

    2016-01-01

    Background Protein energy wasting (PEW) is common in patients undergoing maintenance hemodialysis (MHD) and closely associated with poor outcomes. Insulin resistance and associated alterations in amino acid metabolism are potential pathways leading to PEW. We hypothesized that the measurement of leucine disposal during a hyperinsulinemic- euglycemic-euaminoacidemic clamp (HEAC) procedure would accurately measure the sensitivity to insulin for its actions on concomitant carbohydrate and protein metabolism in MHD patients. Methods We examined 35 MHD patients and 17 control subjects with normal kidney function by hyperinsulinemic-euglycemic clamp (HEGC) followed by HEAC clamp procedure to obtain leucine disposal rate (LDR) along with isotope tracer methodology to assess whole body protein turnover. Results The glucose disposal rate (GDR) by HEGC was 5.1 ± 2.1 mg/kg/min for the MHD patients compared to 6.3 ± 3.9 mg/kg/min for the controls (p = 0.38). The LDR during HEAC was 0.09 ± 0.03 mg/kg/min for the MHD patients compared to 0.11 ± 0.05 mg/kg/min for the controls (p = 0.009). The LDR level was correlated with whole body protein synthesis (r = 0.25; p = 0.08), with whole body protein breakdown (r = −0.38 p = 0.01) and net protein balance (r = 0.85; p < 0.001) in the overall study population. Correlations remained significant in subgroup analysis. The GDR derived by HEGC and LDR correlated well in the controls (r = 0.79, p < 0.001), but less so in the MHD patients (r = 0.58, p < 0.001). Conclusions Leucine disposal rate reliably measures amino acid utilization in MHD patients and controls in response to high dose insulin. PMID:27413537

  12. The increase in animal mortality risk following exposure to sparsely ionizing radiation is not linear quadratic with dose

    DOE PAGESBeta

    Haley, Benjamin M.; Paunesku, Tatjana; Grdina, David J.; Woloschak, Gayle E.; Aravindan, Natarajan

    2015-12-09

    The US government regulates allowable radiation exposures relying, in large part, on the seventh report from the committee to estimate the Biological Effect of Ionizing Radiation (BEIR VII), which estimated that most contemporary exposures- protracted or low-dose, carry 1.5 fold less risk of carcinogenesis and mortality per Gy than acute exposures of atomic bomb survivors. This correction is known as the dose and dose rate effectiveness factor for the life span study of atomic bomb survivors (DDREFLSS). As a result, it was calculated by applying a linear-quadratic dose response model to data from Japanese atomic bomb survivors and a limitedmore » number of animal studies.« less

  13. The increase in animal mortality risk following exposure to sparsely ionizing radiation is not linear quadratic with dose

    SciTech Connect

    Haley, Benjamin M.; Paunesku, Tatjana; Grdina, David J.; Woloschak, Gayle E.; Aravindan, Natarajan

    2015-12-09

    The US government regulates allowable radiation exposures relying, in large part, on the seventh report from the committee to estimate the Biological Effect of Ionizing Radiation (BEIR VII), which estimated that most contemporary exposures- protracted or low-dose, carry 1.5 fold less risk of carcinogenesis and mortality per Gy than acute exposures of atomic bomb survivors. This correction is known as the dose and dose rate effectiveness factor for the life span study of atomic bomb survivors (DDREFLSS). As a result, it was calculated by applying a linear-quadratic dose response model to data from Japanese atomic bomb survivors and a limited number of animal studies.

  14. Modeling leucine's metabolic pathway and knockout prediction improving the production of surfactin, a biosurfactant from Bacillus subtilis.

    PubMed

    Coutte, François; Niehren, Joachim; Dhali, Debarun; John, Mathias; Versari, Cristian; Jacques, Philippe

    2015-08-01

    A Bacillus subtilis mutant strain overexpressing surfactin biosynthetic genes was previously constructed. In order to further increase the production of this biosurfactant, our hypothesis is that the surfactin precursors, especially leucine, must be overproduced. We present a three step approach for leucine overproduction directed by methods from computational biology. Firstly, we develop a new algorithm for gene knockout prediction based on abstract interpretation, which applies to a recent modeling language for reaction networks with partial kinetic information. Secondly, we model the leucine metabolic pathway as a reaction network in this language, and apply the knockout prediction algorithm with the target of leucine overproduction. Out of the 21 reactions corresponding to potential gene knockouts, the prediction algorithm selects 12 reactions. Six knockouts were introduced in B. subtilis 168 derivatives strains to verify their effects on surfactin production. For all generated mutants, the specific surfactin production is increased from 1.6- to 20.9-fold during the exponential growth phase, depending on the medium composition. These results show the effectiveness of the knockout prediction approach based on formal models for metabolic reaction networks with partial kinetic information, and confirms our hypothesis that precursors supply is one of the main parameters to optimize surfactin overproduction. PMID:26220295

  15. Leucine regulation of the ilvGEDA operon of Serratia marcescens by attenuation is modulated by a single leucine codon.

    PubMed Central

    Hsu, J H; Harms, E; Umbarger, H E

    1985-01-01

    The effect of leucine limitation and of restricted leucine tRNA charging on the expression of the ilvGEDA operon of Serratia marcescens was examined. In this organism, the ilv leader region specifies a putative peptide containing only a single leucine codon that could be involved in leucine-mediated control by attenuation (E. Harms, J.-H. Hsu, C. S. Subrahmanyam, and H. E. Umbarger, J. Bacteriol. 164:207-216, 1985). A plasmid (pPU134) containing the DNA of the S. marcescens ilv control region and three of the associated structural genes was studied as a single chromosomal copy in an Escherichia coli strain auxotrophic for all three branched-chain amino acids. The S. marcescens ilv genes responded to a multivalent control similar to that found in other enteric organisms. Furthermore, the S. marcescens ilv genes were derepressed when the charging of leucine tRNA was restricted in a leuS derivative of E. coli that had been transformed with pPU134. It was concluded that ribosome stalling leading to deattenuation is not dependent on either tandem or a consecutive series of codons for the regulatory amino acid. However, the fact that the single leucine codon is a less frequently used codon (CUA) may be important. The procedure for obtaining the cloned ilv genes in single chromosomal copy exploited the dependence of ColE1 replicons on the polA gene. The cloning experiments also revealed a branched-chain amino acid-glutamate transaminase in S. marcescens that is different from transaminase B. PMID:3900038

  16. A multi-head intradermal electroporation device allows for tailored and increased dose DNA vaccine delivery to the skin.

    PubMed

    McCoy, Jay R; Mendoza, Janess M; Spik, Kristin W; Badger, Catherine; Gomez, Alan F; Schmaljohn, Connie S; Sardesai, Niranjan Y; Broderick, Kate E

    2015-01-01

    The identification of an effective and tolerable delivery method is a necessity for the success of DNA vaccines in the clinic. This article describes the development and validation of a multi-headed intradermal electroporation device which would be applicable for delivering multiple DNA vaccine plasmids simultaneously but spatially separated. Reporter gene plasmids expressing green and red fluorescent proteins were used to demonstrate the impact of spatial separation on DNA delivery to increase the number of transfected cells and avoid interference through visible expression patterns. To investigate the impact of plasmid interference on immunogenicity, a disease target was investigated where issues with multi-valent vaccines had been previously described. DNA-based Hantaan and Puumala virus vaccines were delivered separately or as a combination and the effect of multi-valence was determined by appropriate assays. While a negative impact was observed for both antigenic vaccines when delivered together, these effects were mitigated when the vaccine was delivered using the multi-head device. We also demonstrate how the multi-head device facilitates higher dose delivery to the skin resulting in improved immune responses. This new multi-head platform device is an efficient, tolerable and non-invasive method to deliver multiple plasmid DNA constructs simultaneously allowing the tailoring of delivery sites for combination vaccines. Additionally, this device would allow the delivery of multi-plasmid vaccine formulations without risk of impacted immune responses through interference. Such a low-cost, easy to use device platform for the delivery of multi-agent DNA vaccines would have direct applications by the military and healthcare sectors for mass vaccination purposes. PMID:25839221

  17. A multi-head intradermal electroporation device allows for tailored and increased dose DNA vaccine delivery to the skin.

    PubMed

    McCoy, Jay R; Mendoza, Janess M; Spik, Kristin W; Badger, Catherine; Gomez, Alan F; Schmaljohn, Connie S; Sardesai, Niranjan Y; Broderick, Kate E

    2014-01-01

    The identification of an effective and tolerable delivery method is a necessity for the success of DNA vaccines in the clinic. This manuscript describes the development and validation of a multi-headed intradermal electroporation device which would be applicable for delivering multiple DNA vaccine plasmids simultaneously but spatially separated. Reporter gene plasmids expressing green and red fluorescent proteins were used to demonstrate the impact of spatial separation on DNA delivery to increase the number of transfected cells and avoid interference through visible expression patterns. To investigate the impact of plasmid interference on immunogenicity, a disease target was investigated where issues with multi-valent vaccines had been previously described. DNA-based Hantaan and Puumala virus vaccines were delivered separately or as a combination and the effect of multi-valence was determined by appropriate assays. While a negative impact was observed for both antigenic vaccines when delivered together, these effects were mitigated when the vaccine was delivered using the multi-head device. We also demonstrate how the multi-head device facilitates higher dose delivery to the skin resulting in improved immune responses. This new multi-head platform device is an efficient, tolerable and non-invasive method to deliver multiple plasmid DNA constructs simultaneously allowing the tailoring of delivery sites for combination vaccines. Additionally, this device would allow the delivery of multi-plasmid vaccine formulations without risk of impacted immune responses through interference. Such a low-cost, easy to use device platform for the delivery of multi-agent DNA vaccines would have direct applications by the military and healthcare sectors for mass vaccination purposes. PMID:25483486

  18. Median infectious dose of human norovirus GII.4 in gnotobiotic pigs is decreased by simvastatin treatment and increased by age

    PubMed Central

    Bui, Tammy; Kocher, Jacob; Li, Yanru; Wen, Ke; Li, Guohua; Liu, Fangning; Yang, Xingdong; LeRoith, Tanya; Tan, Ming; Xia, Ming; Zhong, Weiming; Jiang, Xi

    2013-01-01

    Human noroviruses (NoVs), a major cause of viral gastroenteritis, are difficult to study due to the lack of a cell-culture and a small-animal model. Pigs share with humans the types A and H histo-blood group antigens on the intestinal epithelium and have been suggested as a potential model for studies of NoV pathogenesis, immunity and vaccines. In this study, the effects of age and a cholesterol-lowering drug, simvastatin, on the susceptibility of pigs to NoV infection were evaluated. The median infectious dose (ID50) of a genogroup II, genotype 4 (GII.4) 2006b variant was determined. The ID50 in neonatal (4–5 days of age) pigs was ≤2.74×103 viral RNA copies. In older pigs (33–34 days of age), the ID50 was 6.43×104 but decreased to <2.74×103 in simvastatin-fed older pigs. Evidence of NoV infection was obtained by increased virus load in the intestinal contents, cytopathological changes in the small intestine, including irregular microvilli, necrosis and apoptosis, and detection of viral antigen in the tip of villi in duodenum. This GII.4 variant was isolated in 2008 from a patient from whom a large volume of stool was collected. GII.4 NoVs are continuously subjected to selective pressure by human immunity, and antigenically different GII.4 NoV variants emerge every 1–2 years. The determination of the ID50 of this challenge virus is valuable for evaluation of protection against different GII.4 variants conferred by NoV vaccines in concurrence with other GII.4 variants in the gnotobiotic pig model. PMID:23804568

  19. A multi-head intradermal electroporation device allows for tailored and increased dose DNA vaccine delivery to the skin

    PubMed Central

    McCoy, Jay R; Mendoza, Janess M; Spik, Kristin W; Badger, Catherine; Gomez, Alan F; Schmaljohn, Connie S; Sardesai, Niranjan Y; Broderick, Kate E

    2015-01-01

    The identification of an effective and tolerable delivery method is a necessity for the success of DNA vaccines in the clinic. This article describes the development and validation of a multi-headed intradermal electroporation device which would be applicable for delivering multiple DNA vaccine plasmids simultaneously but spatially separated. Reporter gene plasmids expressing green and red fluorescent proteins were used to demonstrate the impact of spatial separation on DNA delivery to increase the number of transfected cells and avoid interference through visible expression patterns. To investigate the impact of plasmid interference on immunogenicity, a disease target was investigated where issues with multi-valent vaccines had been previously described. DNA-based Hantaan and Puumala virus vaccines were delivered separately or as a combination and the effect of multi-valence was determined by appropriate assays. While a negative impact was observed for both antigenic vaccines when delivered together, these effects were mitigated when the vaccine was delivered using the multi-head device. We also demonstrate how the multi-head device facilitates higher dose delivery to the skin resulting in improved immune responses. This new multi-head platform device is an efficient, tolerable and non-invasive method to deliver multiple plasmid DNA constructs simultaneously allowing the tailoring of delivery sites for combination vaccines. Additionally, this device would allow the delivery of multi-plasmid vaccine formulations without risk of impacted immune responses through interference. Such a low-cost, easy to use device platform for the delivery of multi-agent DNA vaccines would have direct applications by the military and healthcare sectors for mass vaccination purposes. PMID:25839221

  20. Low-dose irradiation prior to bone marrow transplantation results in ATM activation and increased lethality in Atm-deficient mice.

    PubMed

    Pietzner, J; Merscher, B M; Baer, P C; Duecker, R P; Eickmeier, O; Fußbroich, D; Bader, P; Del Turco, D; Henschler, R; Zielen, S; Schubert, R

    2016-04-01

    Ataxia telangiectasia is a genetic instability syndrome characterized by neurodegeneration, immunodeficiency, severe bronchial complications, hypersensitivity to radiotherapy and an elevated risk of malignancies. Repopulation with ATM-competent bone marrow-derived cells (BMDCs) significantly prolonged the lifespan and improved the phenotype of Atm-deficient mice. The aim of the present study was to promote BMDC engraftment after bone marrow transplantation using low-dose irradiation (IR) as a co-conditioning strategy. Atm-deficient mice were transplanted with green fluorescent protein-expressing, ATM-positive BMDCs using a clinically relevant non-myeloablative host-conditioning regimen together with TBI (0.2-2.0 Gy). IR significantly improved the engraftment of BMDCs into the bone marrow, blood, spleen and lung in a dose-dependent manner, but not into the cerebellum. However, with increasing doses, IR lethality increased even after low-dose IR. Analysis of the bronchoalveolar lavage fluid and lung histochemistry revealed a significant enhancement in the number of inflammatory cells and oxidative damage. A delay in the resolution of γ-H2AX-expression points to an insufficient double-strand break repair capacity following IR with 0.5 Gy in Atm-deficient splenocytes. Our results demonstrate that even low-dose IR results in ATM activation. In the absence of ATM, low-dose IR leads to increased inflammation, oxidative stress and lethality in the Atm-deficient mouse model. PMID:26752140

  1. High-dose atorvastatin causes a rapid sustained increase in human serum PCSK9 and disrupts its correlation with LDL cholesterol.

    PubMed

    Welder, Greg; Zineh, Issam; Pacanowski, Michael A; Troutt, Jason S; Cao, Guoqing; Konrad, Robert J

    2010-09-01

    Proprotein convertase subtilisin kexin type 9 (PCSK9) is a key regulator of serum LDL-cholesterol (LDL-C) levels. PCSK9 is secreted by the liver into the plasma and binds the hepatic LDL receptor (LDLR), causing its subsequent degradation. We first demonstrated that a moderate dose of atorvastatin (40 mg) increases PCSK9 serum levels, suggesting why increasing statin doses may have diminished efficacy with regard to further LDL-C lowering. Since that initial observation, at least two other groups have reported statin-induced PCSK9 increases. To date, no analysis of the effect of high-dose atorvastatin (80 mg) on PCSK9 over time has been conducted. Therefore, we studied the time course of atorvastatin (80 mg) in human subjects. We measured PCSK9 and lipid levels during a 2-week lead-in baseline period and every 4 weeks thereafter for 16 weeks. We observed that atorvastatin (80 mg) caused a rapid 47% increase in serum PCSK9 at 4 weeks that was sustained throughout 16 weeks of dosing. Importantly, while PCSK9 levels were highly correlated with total cholesterol (TC), LDL-C, and triglyceride (TG) levels at baseline, atorvastatin (80 mg) completely abolished all of these correlations. Together, these results further suggest an explanation for why increasing doses of statins fail to achieve proportional LDL-C lowering. PMID:20525997

  2. L-leucine, L-methionine, and L-phenylalanine share a Na(+)/K (+)-dependent amino acid transporter in shrimp hepatopancreas.

    PubMed

    Duka, Ada; Ahearn, Gregory A

    2013-08-01

    Hepatopancreatic brush border membrane vesicles (BBMV), made from Atlantic White shrimp (Litopenaeus setiferus), were used to characterize the transport properties of (3)H-L-leucine influx by these membrane systems and how other essential amino acids and the cations, sodium and potassium, interact with this transport system. (3)H-L-leucine uptake by BBMV was pH-sensitive and occurred against transient transmembrane concentration gradients in both Na(+)- and K(+)-containing incubation media, suggesting that either cation was capable of providing a driving force for amino acid accumulation. (3)H-L-leucine uptake in NaCl or KCl media were each three times greater in acidic pH (pH 5.5) than in alkaline pH (pH 8.5). The essential amino acid, L-methionine, at 20 mM significantly (p < 0.0001) inhibited the 2-min uptakes of 1 mM (3)H-L-leucine in both Na(+)- and K(+)-containing incubation media. The residual (3)H-L-leucine uptake in the two media were significantly greater than zero (p < 0.001), but not significantly different from each other (p > 0.05) and may represent an L-methionine- and cation-independent transport system. (3)H-L-leucine influxes in both NaCl and KCl incubation media were hyperbolic functions of [L-leucine], following the carrier-mediated Michaelis-Menten equation. In NaCl, (3)H-L-leucine influx displayed a low apparent K M (high affinity) and low apparent J max, while in KCl the transport exhibited a high apparent K M (low affinity) and high apparent J max. L-methionine or L-phenylalanine (7 and 20 mM) were competitive inhibitors of (3)H-L-leucine influxes in both NaCl and KCl media, producing a significant (p < 0.01) increase in (3)H-L-leucine influx K M, but no significant response in (3)H-L-leucine influx J max. Potassium was a competitive inhibitor of sodium co-transport with (3)H-L-leucine, significantly (p < 0.01) increasing (3)H-L-leucine influx K M in the presence of sodium, but having negligible effect on (3)H-L-leucine influx J

  3. Progressive recruitment of cortical and striatal regions by inducible postsynaptic density transcripts after increasing doses of antipsychotics with different receptor profiles: insights for psychosis treatment.

    PubMed

    de Bartolomeis, Andrea; Iasevoli, Felice; Marmo, Federica; Buonaguro, Elisabetta F; Eramo, Anna; Rossi, Rodolfo; Avvisati, Livia; Latte, Gianmarco; Tomasetti, Carmine

    2015-04-01

    Antipsychotics may modulate the transcription of multiple gene programs, including those belonging to postsynaptic density (PSD) network, within cortical and subcortical brain regions. Understanding which brain region is activated progressively by increasing doses of antipsychotics and how their different receptor profiles may impact such an activation could be relevant to better correlate the mechanism of action of antipsychotics both with their efficacy and side effects. We analyzed the differential topography of PSD transcripts by incremental doses of two antipsychotics: haloperidol, the prototypical first generation antipsychotic with prevalent dopamine D2 receptors antagonism, and asenapine, a second generation antipsychotic characterized by multiple receptors occupancy. We investigated the expression of PSD genes involved in synaptic plasticity and previously demonstrated to be modulated by antipsychotics: Homer1a, and its related interacting constitutive genes Homer1b/c and PSD95, as well as Arc, C-fos and Zif-268, also known to be induced by antipsychotics administration. We found that increasing acute doses of haloperidol induced immediate-early genes (IEGs) expression in different striatal areas, which were progressively recruited by incremental doses with a dorsal-to-ventral gradient of expression. Conversely, increasing acute asenapine doses progressively de-recruited IEGs expression in cortical areas and increased striatal genes signal intensity. These effects were mirrored by a progressive reduction in locomotor animal activity by haloperidol, and an opposite increase by asenapine. Thus, we demonstrated for the first time that antipsychotics may progressively recruit PSD-related IEGs expression in cortical and subcortical areas when administered at incremental doses and these effects may reflect a fine-tuned dose-dependent modulation of the PSD. PMID:25649681

  4. Enteral leucine and protein synthesis in skeletal and cardiac muscle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are three members of the Branch Chain Amino Acids: leucine, isoleucine, and valine. As essential amino acids, these amino acids have important functions which include a primary role in protein structure and metabolism. It is intriguing that the requirement for BCAA in humans comprise about 40–...

  5. 21 CFR 862.1460 - Leucine aminopeptidase test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Leucine aminopeptidase test system. 862.1460 Section 862.1460 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...

  6. 21 CFR 862.1460 - Leucine aminopeptidase test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Leucine aminopeptidase test system. 862.1460 Section 862.1460 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...

  7. 21 CFR 862.1460 - Leucine aminopeptidase test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Leucine aminopeptidase test system. 862.1460 Section 862.1460 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...

  8. 21 CFR 862.1460 - Leucine aminopeptidase test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Leucine aminopeptidase test system. 862.1460 Section 862.1460 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...

  9. Sparing Healthy Tissue and Increasing Tumor Dose Using Bayesian Modeling of Geometric Uncertainties for Planning Target Volume Personalization

    SciTech Connect

    Herschtal, Alan; Te Marvelde, Luc; Mengersen, Kerrie; Foroudi, Farshad; Eade, Thomas; Pham, Daniel; Caine, Hannah; Kron, Tomas

    2015-06-01

    Objective: To develop a mathematical tool that can update a patient's planning target volume (PTV) partway through a course of radiation therapy to more precisely target the tumor for the remainder of treatment and reduce dose to surrounding healthy tissue. Methods and Materials: Daily on-board imaging was used to collect large datasets of displacements for patients undergoing external beam radiation therapy for solid tumors. Bayesian statistical modeling of these geometric uncertainties was used to optimally trade off between displacement data collected from previously treated patients and the progressively accumulating data from a patient currently partway through treatment, to optimally predict future displacements for that patient. These predictions were used to update the PTV position and margin width for the remainder of treatment, such that the clinical target volume (CTV) was more precisely targeted. Results: Software simulation of dose to CTV and normal tissue for 2 real prostate displacement datasets consisting of 146 and 290 patients treated with a minimum of 30 fractions each showed that re-evaluating the PTV position and margin width after 8 treatment fractions reduced healthy tissue dose by 19% and 17%, respectively, while maintaining CTV dose. Conclusion: Incorporating patient-specific displacement patterns from early in a course of treatment allows PTV adaptation for the remainder of treatment. This substantially reduces the dose to healthy tissues and thus can reduce radiation therapy–induced toxicities, improving patient outcomes.

  10. Plasma reciprocal pool specific activity predicts that of intracellular free leucine for protein synthesis

    SciTech Connect

    Horber, F.F.; Horber-Feyder, C.M.; Krayer, S.; Schwenk, W.F.; Haymond, M.W. )

    1989-09-01

    We previously proposed that, during the infusion of either labeled leucine or its alpha-ketoacid, alpha-ketoisocaproate (KIC), the plasma specific activity (SA) of the transaminated product of the infused tracer (reciprocal pool SA) may better reflect the intracellular leucine SA than the plasma SA of either infused tracer (primary pool SA). To test this hypothesis, 14 dogs were simultaneously infused intravenously with (3H)leucine and (14C)KIC, and blood and tissue compartments were sampled. The ratios of (3H)-leucine to (14C)leucine (3H)/(14C)leucine in mixed tissue proteins and in the intracellular space of striated muscle were the same as the ratio of the isotope infusion rates and similar, although slightly lower (P less than 0.01), than (3H)KIC/(14C)leucine SA (ratio of reciprocal pool SA) in plasma. Plasma (3H)KIC/(14C)leucine SA were essentially identical to the (3H)/(14C) of leucine in (1) mixed liver proteins, (2) intrahepatic free leucine, and (3) fibrin. The (3H)/(14C)leucine in mixed renal proteins and in the intracellular space of kidney and erythrocytes were similar to those of the venous plasma (3H)/(14C)leucine SA. The plasma (3H)KIC and (14C)leucine SA (the reciprocal pool SA) were similar to the SA of (3H)- and (14C)leucine in the intracellular space of all organs investigated with the exception of kidney. Therefore, in postabsorptive dogs, the plasma SA of the transaminated product of the infused labeled KIC or leucine is an excellent predictor of the intracellular leucine SA in all tissues investigated with the exception of kidney.

  11. Differential increase in taurine levels by low-dose ethanol in the dorsal and ventral striatum revealed by microdialysis with on-line capillary electrophoresis.

    PubMed

    Smith, A; Watson, C J; Frantz, K J; Eppler, B; Kennedy, R T; Peris, J

    2004-07-01

    Ethanol increases taurine efflux in the nucleus accumbens or ventral striatum (VS), a dopaminergic terminal region involved in positive reinforcement. However, this has been found only at ethanol doses above 1 g/kg intraperitoneally, which is higher than what most rats will self-administer. We used a sensitive on-line assay of microdialysate content to test whether lower doses of ethanol selectively increase taurine efflux in VS as opposed to other dopaminergic regions not involved in reinforcement (e.g., dorsal striatum; DS). Adult male rats with microdialysis probes in VS or DS were injected with ethanol (0, 0.5, 1, and 2 g/kg intraperitoneally), and the amino acid content of the dialysate was measured every 11 sec using capillary electrophoresis and laser-induced fluorescence detection. In VS, 0.5 g/kg ethanol significantly increased taurine levels by 20% for 10 min. A similar increase was seen after 1 g/kg ethanol, which lasted for about 20 min after injection. A two-phased taurine efflux was observed with the 2.0 g/kg dose, where taurine was increased by 2-fold after 5 min but it remained elevated by 30% for at least 60 min. In contrast, DS exhibited much smaller dose-related increases in taurine. Glycine, glutamate, serine, and gamma-aminobutyric acid were not systematically affected by lower doses of ethanol; however, 2 g/kg slowly decreased these amino acids in both brain regions during the hour after injection. These data implicate a possible role of taurine in the mechanism of action of ethanol in the VS. The high sensitivity and time resolution afforded by capillary electrophoresis and laser-induced fluorescence detection will be useful for detecting subtle changes of neuronally active amino acids levels due to low doses of ethanol. PMID:15252289

  12. Low-dose sirolimus-eluting hydroxyapatite coating on stents does not increase platelet activation and adhesion ex vivo.

    PubMed

    Alviar, Carlos L; Tellez, Armando; Wang, Michael; Potts, Pamela; Smith, Doug; Tsui, Manus; Budzynski, Wladyslaw; Raizner, Albert E; Kleiman, Neal S; Lev, Eli I; Granada, Juan F; Kaluza, Greg L

    2012-07-01

    We previously found paclitaxel-eluting polymer-coated stents causing more human platelet-monocyte complex formation than bare metal stents in vitro. Presently, we examined patterns of platelet activation and adhesion after exposure to 6 nanofilm HAp-coated (HAp-nano) stents, 6 HAp-microporous-coated (HAp-micro) stents, 5 HAp sirolimus-eluting microporous-coated (HAp-SES) stents and 5 cobalt-chromium stents (BMS) deployed in an in vitro flow system. Blood obtained from healthy volunteers was circulated and sampled at 0, 10, 30 and 60 min. By flow cytometry, there were no significant differences in P-Selectin expression between the 4 stent types (HAp-nano = 32.5%; HAp-micro = 42.5%, HAp-SES = 10.23%, BMS = 7% change from baseline at 60 min, p = NS); PAC-1 antibody binding (HAp-nano = 11.8%; HAp-micro = 2.9%, HAp-SES = 18%, BMS = 6.4% change from baseline at 60 min, p = NS) or PMC formation (HAp-nano = 21.6%; HAp-micro = 4%, HAp-SES = 6.6%, BMS = 17.4% change from baseline at 60 min, p = NS). The 4 stent types did not differ in the average number of platelet clusters >10 μm in diameter by SEM (HAp-nano = 2.39 ± 5.75; HAp-micro = 2.26 ± 3.43; HAp-SES = 1.93 ± 3.24; BMS = 1.94 ± 2.41, p = NS). The majority of the struts in each stent group were only mildly covered by platelets, (HAp-nano = 80%, HAp-micro = 61%, HAp-SES = 78% and BMS = 52.1%, p = NS). The HAp-microporous-coated stents (ECD) attracted slightly more proteinaceous material than bare metal stents (HAp-micro = 35% struts with complete protein coverage, P < 0.0001 vs. other 3 stent types). In conclusion, biomimetic stent coating with nanofilm or microporous hydroxyapatite, even when eluting low-dose sirolimus, does not increase the platelet activation in circulating human blood, or platelet adhesion to stent surface when compared to bare metal stents in vitro. PMID:22350685

  13. Improved tumor localization with increasing dose of indium-111-labeled anti-carcinoembryonic antigen monoclonal antibody ZCE-025 in metastatic colorectal cancer

    SciTech Connect

    Patt, Y.Z.; Lamki, L.M.; Haynie, T.P.; Unger, M.W.; Rosenblum, M.G.; Shirkhoda, A.; Murray, J.L.

    1988-08-01

    Monoclonal antibodies (MoAbs) against carcinoembryonic antigen (CEA) react with human colorectal cancer cells, and when labeled with a gamma-emitting radioisotope, may help to localize known and occult metastatic disease. We tested ZCE-025, a high-affinity immune gamma globulin1 (IgG1) MoAb anti-CEA that does not react with normal granulocyte glycoproteins in a phase I/II trial to determine the reagent's toxicity and its maximum efficacy in detecting metastatic colorectal cancer. Increasing doses of unlabeled ZCE-025 were mixed with 1 mg of Indium-111 (111In)-radiolabeled MoAb and administered intravenously (IV) to 34 patients who had metastatic colorectal cancer. Planar nuclear or single photon emission computed tomographic (SPECT) scans were performed 48 to 72 and 120 to 144 hours later. Total dose of MoAb and scanning sensitivity (number of imaged lesions/number of known lesions) were correlated up to 80 mg. At doses of 2.5 to 20 mg, a mean of 22% of the lesions were imaged; at 40 mg, 77% were imaged (P less than .01). Liver metastases were detected as areas of increased activity (hot) at the 40 mg dose but showed decreased MoAb uptake at lower doses. At the 40 mg dose normal liver parenchymal uptake of the labeled MoAb was lower with respect to blood pool compared with the other doses. At 80 mg, however, sensitivity of detection declined to 21%. One milligram of 111In-labeled ZCE-025 antibody coinfused with 39 mg of unlabeled antibody appeared optimal for detecting metastatic colorectal cancer, particularly in the liver. Although the exact mechanism(s) for this dose effect is currently unknown, a partial blocking effect of unlabeled antibody with a change in MoAb biodistribution may be occurring.

  14. High dose lycopene supplementation increases hepatic CYP2E1 protein and TNF-alpha expression in alcohol fed rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lycopene (LYC) has attracted considerable attention due to its antioxidant and anti-inflammatory effects. However, in vivo knowledge of possible interactions between escalating doses of LYC and chronic alcohol ingestion are lacking. F-344 rats (6 groups, n = 10) were fed either a liquid ethanol Lie...

  15. High Dose Lycopene Supplementation Increases Hepatic CYP2E1 Protein and Inflammation in Alcohol-Fed Rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent in vitro evidence suggests that the antioxidant lycopene can prevent alcohol induced oxidative stress and inflammation. However, in vivo knowledge of possible interactions between escalating doses of lycopene and chronic alcohol ingestion are lacking. In the present study, we investigated p...

  16. Increased active metabolite formation explains the greater platelet inhibition with prasugrel compared to high-dose clopidogrel.

    PubMed

    Payne, Christopher D; Li, Ying Grace; Small, David S; Ernest, C Steven; Farid, Nagy A; Jakubowski, Joseph A; Brandt, John T; Salazar, Daniel E; Winters, Kenneth J

    2007-11-01

    Prasugrel pharmacodynamics and pharmacokinetics after a 60-mg loading dose (LD) and daily 10-mg maintenance doses (MD) were compared in a 3-way crossover study to clopidogrel 600-mg/75-mg and 300-mg/75-mg LD/MD in 41 healthy, aspirin-free subjects. Each LD was followed by 7 days of daily MD and a 14-day washout period. Inhibition of platelet aggregation (IPA) was assessed by turbidometric aggregometry (20 and 5 microM ADP). Prasugrel 60-mg achieved higher mean IPA (54%) 30 minutes post-LD than clopidogrel 300-mg (3%) or 600-mg (6%) (P < 0.001) and greater IPA by 1 hour (82%) and 2 hours (91%) than the 6-hour IPA for clopidogrel 300-mg (51%) or 600-mg (69%) (P < 0.01). During MD, IPA for prasugrel 10-mg (78%) exceeded that of clopidogrel (300-mg/75-mg, 56%; 600-mg/75-mg, 52%; P < 0.001). Active metabolite area under the concentration-time curve (AUC0-tlast) after prasugrel 60-mg (594 ng.hr/mL) was 2.2 times that after clopidogrel 600-mg. Prasugrel active metabolite AUC0-tlast was consistent with dose-proportionality from 10-mg to 60-mg, while clopidogrel active metabolite AUC0-tlast exhibited saturable absorption and/or metabolism. In conclusion, greater exposure to prasugrel's active metabolite results in faster onset, higher levels, and less variability of platelet inhibition compared with high-dose clopidogrel in healthy subjects. PMID:18030066

  17. Clinical factors increasing radiation doses to patients undergoing long-lasting procedures: Abdominal stent-graft implantation

    PubMed Central

    Majewska, Natalia; Stanisic, Michal G.; Blaszak, Magdalena Aleksandra; Juszkat, Robert; Frankiewicz, Maciej; Krasinski, Zbigniew; Makalowski, Marcin; Majewski, Waclaw

    2011-01-01

    Summary Background An important negative factor of EVAR is the radiation acquired during long-lasting procedures. The aim of the study was to document the radiation doses of EVAR and to discuss potential reasons for prolongation of radiological procedures. Material/Methods Dose-area product (DAP) (Gy cm2) and air kerma (AK) (Gy) obtained during EVAR from 92 patients were analyzed retrospectively in regards to body mass index (BMI), angulations of aneurysm neck, length of aneurysm neck and occurrence of tortuosity of iliac arteries. Results Total AK for fluoroscopy differed significantly between normal BMI (373 mGy) and BMI 25–29.9 (1125 mGy) or BMI >30 (1085 mGy). Iliac artery tortuosities >45° and short aneurysm necks caused higher doses of total AK (1097 mGy and 1228 mGy, respectively) than iliac artery tortuosities <45° and long aneurysm necks (605 mGy and 720 mGy, respectively). Conclusions The main factors contributing to a high radiation dose being acquired by patients during EVAR are: BMI >25, tortuosity of iliac arteries >45° and short aneurysm necks. PMID:22037751

  18. Leucine kinetics from (2H3)- and ( sup 13 C)leucine infused simultaneously by gut and vein

    SciTech Connect

    Hoerr, R.A.; Matthews, D.E.; Bier, D.M.; Young, V.R. )

    1991-01-01

    In amino acid tracer kinetic studies of the fed state, ingested amino acid may be taken up during its initial transit through splanchnic tissues and thus not enter the plasma compartment where tracer is infused. To investigate this possibility, adult human subjects received simultaneous intravenous (iv) and intragastric (ig) leucine tracer infusions, first during a postabsorptive (PA) 4-h primed continuous ig infusion of L-(1-13C)-leucine and L-(5,5,5-2H3)leucine iv, followed on a separate day by a fed infusion, in which an ig infusion of a liquid formula was started 2 h before the tracer infusion and continued throughout the tracer study. Subjects were accustomed to a constant experimental diet supplying 1.5 g protein.kg-1.day-1 and 41-45 kcal.kg-1.day-1 for 7 and 12 days before the PA and fed studies, respectively. For the PA study, plasma enrichment for the ig tracer was 3.34 +/- 0.27 (SE) mol + excess and for the iv tracer it was 4.18 +/- 0.10 (P less than 0.02). Enrichments of alpha-keto-isocaproic acid (KIC) were 3.24 +/- 0.16 (ig) and 3.02 +/- 0.14 (iv), respectively (not significant (NS)). For the fed study, plasma leucine enrichment for the ig tracer was 2.15 +/- 0.14 and for the iv tracer was 2.84 +/- 0.09 (P less than 0.02). KIC enrichments were 2.02 +/- 0.08 (ig) and 2.24 +/- 0.08 (iv), respectively (NS). In the PA study, the ratio of the plasma leucine enrichments for the ig and iv tracers was 0.80 +/- 0.06 and in the fed experiment, 0.76 +/- 0.05, respectively.

  19. Interaction of Prevotella intermedia Strain 17 Leucine-Rich Repeat Domain Protein AdpF with Eukaryotic Cells Promotes Bacterial Internalization

    PubMed Central

    Sengupta, Dipanwita; Kang, Dae-Joong; Anaya-Bergman, Cecilia; Wyant, Tiana; Ghosh, Arnab K.; Miyazaki, Hiroshi

    2014-01-01

    Prevotella intermedia is an oral bacterium implicated in a variety of oral diseases. Although internalization of this bacterium by nonphagocytic host cells is well established, the molecular players mediating the process are not well known. Here, the properties of a leucine-rich repeat (LRR) domain protein, designated AdpF, are described. This protein contains a leucine-rich region composed of 663 amino acid residues, and molecular modeling shows that it folds into a classical curved solenoid structure. The cell surface localization of recombinant AdpF (rAdpF) was confirmed by electron and confocal microscopy analyses. The recombinant form of this protein bound fibronectin in a dose-dependent manner. Furthermore, the protein was internalized by host cells, with the majority of the process accomplished within 30 min. The internalization of rAdpF was inhibited by nystatin, cytochalasin, latrunculin, nocodazole, and wortmannin, indicating that microtubules, microfilaments, and signal transduction are required for the invasion. It is noteworthy that preincubation of eukaryotic cells with AdpF increased P. intermedia 17 internalization by 5- and 10-fold for HeLa and NIH 3T3 fibroblast cell lines, respectively. The addition of the rAdpF protein was also very effective in inducing bacterial internalization into the oral epithelial cell line HN4, as well as into primary cells, including human oral keratinocytes (HOKs) and human umbilical vein endothelial cells (HUVECs). Finally, cells exposed to P. intermedia 17 internalized the bacteria more readily upon reinfection. Taken together, our data demonstrate that rAdpF plays a role in the internalization of P. intermedia 17 by a variety of host cells. PMID:24711565

  20. Dietary Leucine Supplementation Improves the Mucin Production in the Jejunal Mucosa of the Weaned Pigs Challenged by Porcine Rotavirus.

    PubMed

    Mao, Xiangbing; Liu, Minghui; Tang, Jun; Chen, Hao; Chen, Daiwen; Yu, Bing; He, Jun; Yu, Jie; Zheng, Ping

    2015-01-01

    The present study was mainly conducted to determine whether dietary leucine supplementation could attenuate the decrease of the mucin production in the jejunal mucosa of weaned pigs infected by porcine rotavirus (PRV). A total of 24 crossbred barrows weaned at 21 d of age were assigned randomly to 1 of 2 diets supplemented with 1.00% L-leucine or 0.68% L-alanine (isonitrogenous control) for 17 d. On day 11, all pigs were orally infused PRV or the sterile essential medium. During the first 10 d of trial, dietary leucine supplementation could improve the feed efficiency (P = 0.09). The ADG and feed efficiency were impaired by PRV infusion (P<0.05). PRV infusion also increased mean cumulative score of diarrhea, serum rotavirus antibody concentration and crypt depth of the jejunal mucosa (P<0.05), and decreased villus height: crypt depth (P = 0.07), goblet cell numbers (P<0.05), mucin 1 and 2 concentrations (P<0.05) and phosphorylated mTOR level (P<0.05) of the jejunal mucosa in weaned pigs. Dietary leucine supplementation could attenuate the effects of PRV infusion on feed efficiency (P = 0.09) and mean cumulative score of diarrhea (P = 0.09), and improve the effects of PRV infusion on villus height: crypt depth (P = 0.06), goblet cell numbers (P<0.05), mucin 1 (P = 0.08) and 2 (P = 0.07) concentrations and phosphorylated mTOR level (P = 0.08) of the jejunal mucosa in weaned pigs. These results suggest that dietary 1% leucine supplementation alleviated the decrease of mucin production and goblet cell numbers in the jejunal mucosa of weaned pigs challenged by PRV possibly via activation of the mTOR signaling. PMID:26336074

  1. Dietary Leucine Supplementation Improves the Mucin Production in the Jejunal Mucosa of the Weaned Pigs Challenged by Porcine Rotavirus

    PubMed Central

    Mao, Xiangbing; Liu, Minghui; Tang, Jun; Chen, Hao; Chen, Daiwen; Yu, Bing; He, Jun; Yu, Jie; Zheng, Ping

    2015-01-01

    The present study was mainly conducted to determine whether dietary leucine supplementation could attenuate the decrease of the mucin production in the jejunal mucosa of weaned pigs infected by porcine rotavirus (PRV). A total of 24 crossbred barrows weaned at 21 d of age were assigned randomly to 1 of 2 diets supplemented with 1.00% L-leucine or 0.68% L-alanine (isonitrogenous control) for 17 d. On day 11, all pigs were orally infused PRV or the sterile essential medium. During the first 10 d of trial, dietary leucine supplementation could improve the feed efficiency (P = 0.09). The ADG and feed efficiency were impaired by PRV infusion (P<0.05). PRV infusion also increased mean cumulative score of diarrhea, serum rotavirus antibody concentration and crypt depth of the jejunal mucosa (P<0.05), and decreased villus height: crypt depth (P = 0.07), goblet cell numbers (P<0.05), mucin 1 and 2 concentrations (P<0.05) and phosphorylated mTOR level (P<0.05) of the jejunal mucosa in weaned pigs. Dietary leucine supplementation could attenuate the effects of PRV infusion on feed efficiency (P = 0.09) and mean cumulative score of diarrhea (P = 0.09), and improve the effects of PRV infusion on villus height: crypt depth (P = 0.06), goblet cell numbers (P<0.05), mucin 1 (P = 0.08) and 2 (P = 0.07) concentrations and phosphorylated mTOR level (P = 0.08) of the jejunal mucosa in weaned pigs. These results suggest that dietary 1% leucine supplementation alleviated the decrease of mucin production and goblet cell numbers in the jejunal mucosa of weaned pigs challenged by PRV possibly via activation of the mTOR signaling. PMID:26336074

  2. Paramagnetic molecular centers in the gamma-irradiated novel compound of aluminum and leucine, Al 6O 4(OH) 10(leucine) 2·5H 2O

    NASA Astrophysics Data System (ADS)

    Nothig-Laslo, Vesna; Himdan, Takialdin A.; Bilinski, Halka

    A new microcrystalline compound Al 6O 4(OH) 10(leucine) 2·5H 2O of possible biological and biochemical interest has been prepared and characterized by chemical analysis, i.r. spectrum, X-ray diffraction and thermogravimetric analysis. It was exposed to γ-irradiation at 77 K and at room temperature. Paramagnetic species formed were studied by ESR spectroscopy. The leucine radical ? has been identified which seems to be stabilized in the aluminium leucine compound by crystalline water. Coordinated leucine molecule in aluminium hydroxide acts as a trap for γ-irradiation energy.

  3. Augmented renal clearance implies a need for increased amoxicillin-clavulanic acid dosing in critically ill children.

    PubMed

    De Cock, Pieter A J G; Standing, Joseph F; Barker, Charlotte I S; de Jaeger, Annick; Dhont, Evelyn; Carlier, Mieke; Verstraete, Alain G; Delanghe, Joris R; Robays, Hugo; De Paepe, Peter

    2015-11-01

    There is little data available to guide amoxicillin-clavulanic acid dosing in critically ill children. The primary objective of this study was to investigate the pharmacokinetics of both compounds in this pediatric subpopulation. Patients admitted to the pediatric intensive care unit (ICU) in whom intravenous amoxicillin-clavulanic acid was indicated (25 to 35 mg/kg of body weight every 6 h) were enrolled. Population pharmacokinetic analysis was conducted, and the clinical outcome was documented. A total of 325 and 151 blood samples were collected from 50 patients (median age, 2.58 years; age range, 1 month to 15 years) treated with amoxicillin and clavulanic acid, respectively. A three-compartment model for amoxicillin and a two-compartment model for clavulanic acid best described the data, in which allometric weight scaling and maturation functions were added a priori to scale for size and age. In addition, plasma cystatin C and concomitant treatment with vasopressors were identified to have a significant influence on amoxicillin clearance. The typical population values of clearance for amoxicillin and clavulanic acid were 17.97 liters/h/70 kg and 12.20 liters/h/70 kg, respectively. In 32% of the treated patients, amoxicillin-clavulanic acid therapy was stopped prematurely due to clinical failure, and the patient was switched to broader-spectrum antibiotic treatment. Monte Carlo simulations demonstrated that four-hourly dosing of 25 mg/kg was required to achieve the therapeutic target for both amoxicillin and clavulanic acid. For patients with augmented renal function, a 1-h infusion was preferable to bolus dosing. Current published dosing regimens result in subtherapeutic concentrations in the early period of sepsis due to augmented renal clearance, which risks clinical failure in critically ill children, and therefore need to be updated. (This study has been registered at Clinicaltrials.gov as an observational study [NCT02456974].). PMID:26349821

  4. Augmented Renal Clearance Implies a Need for Increased Amoxicillin-Clavulanic Acid Dosing in Critically Ill Children

    PubMed Central

    Standing, Joseph F.; Barker, Charlotte I. S.; de Jaeger, Annick; Dhont, Evelyn; Carlier, Mieke; Verstraete, Alain G.; Delanghe, Joris R.; Robays, Hugo; De Paepe, Peter

    2015-01-01

    There is little data available to guide amoxicillin-clavulanic acid dosing in critically ill children. The primary objective of this study was to investigate the pharmacokinetics of both compounds in this pediatric subpopulation. Patients admitted to the pediatric intensive care unit (ICU) in whom intravenous amoxicillin-clavulanic acid was indicated (25 to 35 mg/kg of body weight every 6 h) were enrolled. Population pharmacokinetic analysis was conducted, and the clinical outcome was documented. A total of 325 and 151 blood samples were collected from 50 patients (median age, 2.58 years; age range, 1 month to 15 years) treated with amoxicillin and clavulanic acid, respectively. A three-compartment model for amoxicillin and a two-compartment model for clavulanic acid best described the data, in which allometric weight scaling and maturation functions were added a priori to scale for size and age. In addition, plasma cystatin C and concomitant treatment with vasopressors were identified to have a significant influence on amoxicillin clearance. The typical population values of clearance for amoxicillin and clavulanic acid were 17.97 liters/h/70 kg and 12.20 liters/h/70 kg, respectively. In 32% of the treated patients, amoxicillin-clavulanic acid therapy was stopped prematurely due to clinical failure, and the patient was switched to broader-spectrum antibiotic treatment. Monte Carlo simulations demonstrated that four-hourly dosing of 25 mg/kg was required to achieve the therapeutic target for both amoxicillin and clavulanic acid. For patients with augmented renal function, a 1-h infusion was preferable to bolus dosing. Current published dosing regimens result in subtherapeutic concentrations in the early period of sepsis due to augmented renal clearance, which risks clinical failure in critically ill children, and therefore need to be updated. (This study has been registered at Clinicaltrials.gov as an observational study [NCT02456974].) PMID:26349821

  5. Effect of Increasing Doses of γ-Radiation on Bone Marrow Stromal Cells Grown on Smooth and Rough Titanium Surfaces

    PubMed Central

    Huang, Bo; Guang, Mengkai; Ye, Jun; Gong, Ping; Tang, Hua

    2015-01-01

    Radiation therapy for oral and maxillofacial tumors could damage bone marrow stromal cells (BMSCs) in jaw, which caused dental implant failure. However, how radiation affects BMSCs on SLA (sandblasted with large-grits, acid-etched) surfaces is still unknown. The aim of this study was to investigate effect of different dose of γ-radiation on BMSCs on SLA and PT (polished titanium) surfaces. Rat BMSCs were radiated with 2, 4, and 8 Gy γ-radiation and then seeded on both surfaces. Cell adhesion, spreading, and proliferation were tested. The osteogenesis and the adipogenesis ability were examined by Alizarin-Red and Oil-Red staining, respectively. Real-time PCR was performed to detect osteogenic (osteocalcin, OCN; runt-related transcription factor 2, Runx2) and adipogenic (peroxisome proliferator-activated receptor gamma, PPARγ) gene expression at days 7 and 14 postirradiation. Results showed that γ-radiation reduced cell proliferation, adhesion, spreading, and osteogenic differentiation. 2 Gy radiation promoted adipogenic differentiation, but it was significantly decreased when dosage reached 4 Gy. In conclusion, results suggest that γ-radiation influenced BMSCs behaviors in a dosage-dependent manner except adipogenic differentiation, low dose promoted it, and high dose inhibited it. This effect was influenced by surface characteristics, which may explain the different failure rate of various implants in patients after radiation. PMID:26257788

  6. SU-E-I-82: Improving CT Image Quality for Radiation Therapy Using Iterative Reconstruction Algorithms and Slightly Increasing Imaging Doses

    SciTech Connect

    Noid, G; Chen, G; Tai, A; Li, X

    2014-06-01

    Purpose: Iterative reconstruction (IR) algorithms are developed to improve CT image quality (IQ) by reducing noise without diminishing spatial resolution or contrast. For CT in radiation therapy (RT), slightly increasing imaging dose to improve IQ may be justified if it can substantially enhance structure delineation. The purpose of this study is to investigate and to quantify the IQ enhancement as a result of increasing imaging doses and using IR algorithms. Methods: CT images were acquired for phantoms, built to evaluate IQ metrics including spatial resolution, contrast and noise, with a variety of imaging protocols using a CT scanner (Definition AS Open, Siemens) installed inside a Linac room. Representative patients were scanned once the protocols were optimized. Both phantom and patient scans were reconstructed using the Sinogram Affirmed Iterative Reconstruction (SAFIRE) and the Filtered Back Projection (FBP) methods. IQ metrics of the obtained CTs were compared. Results: IR techniques are demonstrated to preserve spatial resolution as measured by the point spread function and reduce noise in comparison to traditional FBP. Driven by the reduction in noise, the contrast to noise ratio is doubled by adopting the highest SAFIRE strength. As expected, increasing imaging dose reduces noise for both SAFIRE and FBP reconstructions. The contrast to noise increases from 3 to 5 by increasing the dose by a factor of 4. Similar IQ improvement was observed on the CTs for selected patients with pancreas and prostrate cancers. Conclusion: The IR techniques produce a measurable enhancement to CT IQ by reducing the noise. Increasing imaging dose further reduces noise independent of the IR techniques. The improved CT enables more accurate delineation of tumors and/or organs at risk during RT planning and delivery guidance.

  7. ATRAZINE DOES NOT INDUCE GASTROINTESTINAL DISCOMFORT (PICA) IN RATS AT DOSES THAT INCREASE HPA-AXIS ACTIVATION AND CAUSE CONDITIONED TASTE AVERSION.

    EPA Science Inventory

    Previous work has shown that a single oral administration of atrazine (ATR), a chlorotriazine herbicide, induces dose-dependent increases in plasma adrenocorticotropic hormone (ACTH) and serum corticosterone (CORT), with a NOEL equal to 5mg/kg. The mechanism for these effects ...

  8. ATRAZINE DOES NOT INDUCE GASTROINTESTINAL DISCOMFORT (PICA) IN RATS AT DOSES THAT INCREASE ACTH ANDCORTICOSTERONE RELEASE AND CAUSE CONDITIONED TASTE AVERSION.

    EPA Science Inventory

    Previous work has shown that a single oral administration of atrazine (ATR), a chlorotriazine herbicide, induces dose-dependent increases in plasma adrenocorticotropic hormone (ACTH) and serum corticosterone (CORT), with a LOEL of 12.5mg/kg. The mechanism for these effects is unk...

  9. The Increase in Animal Mortality Risk following Exposure to Sparsely Ionizing Radiation Is Not Linear Quadratic with Dose

    PubMed Central

    Haley, Benjamin M.; Paunesku, Tatjana; Grdina, David J.; Woloschak, Gayle E.

    2015-01-01

    Introduction The US government regulates allowable radiation exposures relying, in large part, on the seventh report from the committee to estimate the Biological Effect of Ionizing Radiation (BEIR VII), which estimated that most contemporary exposures- protracted or low-dose, carry 1.5 fold less risk of carcinogenesis and mortality per Gy than acute exposures of atomic bomb survivors. This correction is known as the dose and dose rate effectiveness factor for the life span study of atomic bomb survivors (DDREFLSS). It was calculated by applying a linear-quadratic dose response model to data from Japanese atomic bomb survivors and a limited number of animal studies. Methods and Results We argue that the linear-quadratic model does not provide appropriate support to estimate the risk of contemporary exposures. In this work, we re-estimated DDREFLSS using 15 animal studies that were not included in BEIR VII’s original analysis. Acute exposure data led to a DDREFLSS estimate from 0.9 to 3.0. By contrast, data that included both acute and protracted exposures led to a DDREFLSS estimate from 4.8 to infinity. These two estimates are significantly different, violating the assumptions of the linear-quadratic model, which predicts that DDREFLSS values calculated in either way should be the same. Conclusions Therefore, we propose that future estimates of the risk of protracted exposures should be based on direct comparisons of data from acute and protracted exposures, rather than from extrapolations from a linear-quadratic model. The risk of low dose exposures may be extrapolated from these protracted estimates, though we encourage ongoing debate as to whether this is the most valid approach. We also encourage efforts to enlarge the datasets used to estimate the risk of protracted exposures by including both human and animal data, carcinogenesis outcomes, a wider range of exposures, and by making more radiobiology data publicly accessible. We believe that these steps will

  10. Activation of the mTOR pathway by the amino acid (L)-leucine in the 5q- syndrome and other ribosomopathies.

    PubMed

    Boultwood, Jacqueline; Yip, Bon Ham; Vuppusetty, Chaitanya; Pellagatti, Andrea; Wainscoat, James S

    2013-01-01

    Patients with the 5q- syndrome and Diamond-Blackfan anemia (DBA) suffer from a severe macrocytic anemia. The 5q- syndrome and DBA are disorders of aberrant ribosome biogenesis (ribosomopathies) and haploinsufficiency of the ribosomal protein genes RPS14 and RPS19, respectively, underlies the anemia found in these disorders. Erythroblasts obtained from patients with the 5q- syndrome and DBA show impaired mRNA translation and this defect in translation may represent a potential therapeutic target in these ribosomopathies. There are some indications that the amino acid l-leucine, a translation enhancer, may have some efficacy in this group of disorders. Recent studies have shown that l-leucine treatment of zebrafish and murine models of the 5q- syndrome and DBA results in a marked improvement in the anemia. l-leucine treatment of RPS14-deficient and RPS19-deficient erythroblasts and erythroblasts from patients with the 5q- syndrome has been shown to result in an increase in cell proliferation, erythroid differentiation and mRNA translation in culture. l-leucine has been shown to improve hemoglobin levels and transfusion independence in a patient with DBA. l-leucine activates the mTOR (mammalian target of rapamycin) signaling pathway that controls cell growth and mRNA translation. There is evidence to suggest that the promotion of translation via the mTOR pathway by l-leucine is the mechanism that underlies the enhanced erythroid progenitor cell growth and differentiation observed in animal and cellular models of the 5q- syndrome and DBA treated with this amino acid. These data support the rationale for clinical trials of l-leucine as a therapeutic agent for the 5q- syndrome and DBA. PMID:23031788

  11. Leucine-enriched essential amino acids attenuate inflammation in rat muscle and enhance muscle repair after eccentric contraction.

    PubMed

    Kato, Hiroyuki; Miura, Kyoko; Nakano, Sayako; Suzuki, Katsuya; Bannai, Makoto; Inoue, Yoshiko

    2016-09-01

    Eccentric exercise results in prolonged muscle damage that may lead to muscle dysfunction. Although inflammation is essential to recover from muscle damage, excessive inflammation may also induce secondary damage, and should thus be suppressed. In this study, we investigated the effect of leucine-enriched essential amino acids on muscle inflammation and recovery after eccentric contraction. These amino acids are known to stimulate muscle protein synthesis via mammalian target of rapamycin (mTOR), which, is also considered to alleviate inflammation. Five sets of 10 eccentric contractions were induced by electrical stimulation in the tibialis anterior muscle of male SpragueDawley rats (8-9 weeks old) under anesthesia. Animals received a 1 g/kg dose of a mixture containing 40 % leucine and 60 % other essential amino acids or distilled water once a day throughout the experiment. Muscle dysfunction was assessed based on isometric dorsiflexion torque, while inflammation was evaluated by histochemistry. Gene expression of inflammatory cytokines and myogenic regulatory factors was also measured. We found that leucine-enriched essential amino acids restored full muscle function within 14 days, at which point rats treated with distilled water had not fully recovered. Indeed, muscle function was stronger 3 days after eccentric contraction in rats treated with amino acids than in those treated with distilled water. The amino acid mix also alleviated expression of interleukin-6 and impeded infiltration of inflammatory cells into muscle, but did not suppress expression of myogenic regulatory factors. These results suggest that leucine-enriched amino acids accelerate recovery from muscle damage by preventing excessive inflammation. PMID:27168073

  12. Characterization of Leucine Auxotrophs of the White Rot Basidiomycete Phanerochaete chrysosporium

    PubMed Central

    Molskness, Theodore A.; Alic, Margaret; Gold, Michael H.

    1986-01-01

    Six leucine auxotrophic strains of the white rot basidiomycete Phanerochaete chrysosporium were characterized genetically and biochemically. Complementation studies involving the use of heterokaryons identified three leucine complementation groups. Since all of the leucine auxotrophs grew on minimal medium supplemented with α-ketoisocaproate as well as with leucine, the transaminase catalyzing the last step in the leucine pathway was apparently normal in all strains. Therefore, the wild-type, auxotrophic, and several heterokaryotic strains were assayed for the activities of the other enzymes specific to leucine biosynthesis. Leu2 and Leu4 strains (complementation group I) lacked only α-isopropylmalate synthase activity; Leu3 and Leu6 strains (group III) lacked isopropylmalate isomerase activity; and Leu1 and Leu5 strains (group II) lacked β-isopropylmalate dehydrogenase. Heterokaryons formed from leucine auxotrophs of different complementation groups had levels of activity for all three enzymes similar to those found in the wild-type strain. PMID:16347073

  13. [Treatment of overactive bladder in older women increased doses of antimuscarinic drugs safe and effective alternative to existing methods].

    PubMed

    Kosilov, K V; Loparev, S A; Krasnykh, M A; Kosilova, L V

    2014-01-01

    The study included 95 female patients of 65 to 74 years (average age 67,1 years), who previously (more than 6 months before this study) took a course of monotherapy with hydrochloride trospium in higher dosages with unstable or weak effect. In this study, all patients were divided into three groups and were treated with two antimuscarinic drugs. The majority of older women suffering from OAB and treatment-resistant taking one antimuscarinic drug in high doses showed a significant positive progress in a state by adding a second antimuscarinic agent. The received side effects do not exceed thereof in comparison with treatment with a single drug. PMID:25051773

  14. Leucine incorporation into mixed skeletal muscle protein in humans

    SciTech Connect

    Nair, K.S.; Halliday, D.; Griggs, R.C. Clinical Research Centre, Harrow )

    1988-02-01

    Fractional mixed skeletal muscle protein synthesis (FMPS) was estimated in 10 postabsorptive healthy men by determining the increment in the abundance of ({sup 13}C)-leucine in quadriceps muscle protein during an intravenous infusion of L-(1-{sup 13}C)leucine. Whole-body muscle protein synthesis (MPS) was calculated based on the estimation of muscle mass from creatinine excretion and compared with whole-body protein synthesis (WBPS) calculated from the nonoxidative portion of leucine flux. A significant correlation was found between MPS. The contribution of MPS to WBPS was 27 {plus minus} 1%, which is comparable to the reports in other species. Morphometric analyses of adjacent muscle samples in eight subjects demonstrated that the biopsy specimens consisted of 86.5 {plus minus} 2% muscular as opposed to other tissues. Because fiber type composition varies between biopsies, the authors examined the relationship between proportions of each fiber type and FMPS. Variation in the composition of biopsies and in fiber-type proportion did not affect the estimation of muscle protein synthesis rate. They conclude that stable isotope techniques using serial needle biopsies permit the direct measurement of FMPS in humans and that this estimation is correlated with an indirect estimation of WBPS.

  15. Penicillin concentrations in serum, milk, and urine following intramuscular and subcutaneous administration of increasing doses of procaine penicillin G in lactating dairy cows.

    PubMed Central

    Dubreuil, P; Daigneault, J; Couture, Y; Guay, P; Landry, D

    2001-01-01

    Eight healthy, non-pregnant, crossbred Holstein dairy cows (557-682 kg) within their first 3 months of lactation (13-21.5 kg of milk/day) were used. Cows were kept in tie stalls for the whole experiment. The 8 cows were randomly assigned to 2 (IM and SC) 4 x 4 balanced Latin square design experiments. Doses of procaine penicillin G (PPG) (300000 IU/mL) in each square were 7000, 14000, 21000 and 28000 IU/kg and were injected IM or SC once daily for 5 consecutive days. Volumes of PPG per site of injection never exceeded 20 mL. Blood was collected to determine the Cmax, Tmax, and AUC; urine and milk were also taken to measure the persistence of PPG in these fluids. Results show that serum Cmax and Tmax were only slightly affected by increasing the doses or the route of administration, whereas the AUC was linearly increased in relation to the dose injected in both modes of injection. In the urine, Cmax varied from 160 to 388 IU/mL and Tmax from 72-120 h during 5 consecutive days of PPG injection. A dose effect in Cmax was observed only for the IM route of administration and no variation (P > 0.05) was found between the IM and SC routes. Milk Cmax concentrations were only increased by the dose regimen in the IM group. At doses of 21000 and 28000 IU/kg, the IM group had a higher (P > 0.05) Cmax when compared with the SC groups. Milk PPG residues were not detectable over 96 h following the last IM injection, independently of the dose injected. However milk PPG residues were detected for up to 132 h following the last SC injection. These results show that when PPG is injected IM once daily in volumes not exceeding 20 mL/site at doses as high as 28000 IU/kg, the withdrawal period should be at least 96 h. Therefore, in the present model, there was no advantage to inject PPG by SC route to improve PPG kinetic parameters as the AUC, Cmax, or Tmax. PMID:11480523

  16. Leucine supplementation does not affect protein turnover and impairs the beneficial effects of endurance training on glucose homeostasis in healthy mice.

    PubMed

    Costa Júnior, José M; Rosa, Morgana R; Protzek, André O; de Paula, Flávia M; Ferreira, Sandra M; Rezende, Luiz F; Vanzela, Emerielle C; Zoppi, Cláudio C; Silveira, Leonardo R; Kettelhut, Isis C; Boschero, Antonio C; de Oliveira, Camila A M; Carneiro, Everardo M

    2015-04-01

    Endurance exercise training as well as leucine supplementation modulates glucose homeostasis and protein turnover in mammals. Here, we analyze whether leucine supplementation alters the effects of endurance exercise on these parameters in healthy mice. Mice were distributed into sedentary (C) and exercise (T) groups. The exercise group performed a 12-week swimming protocol. Half of the C and T mice, designated as the CL and TL groups, were supplemented with leucine (1.5 % dissolved in the drinking water) throughout the experiment. As well known, endurance exercise training reduced body weight and the retroperitoneal fat pad, increased soleus mass, increased VO2max, decreased muscle proteolysis, and ameliorated peripheral insulin sensitivity. Leucine supplementation had no effect on any of these parameters and worsened glucose tolerance in both CL and TL mice. In the soleus muscle of the T group, AS-160(Thr-642) (AKT substrate of 160 kDa) and AMPK(Thr-172) (AMP-Activated Protein Kinase) phosphorylation was increased by exercise in both basal and insulin-stimulated conditions, but it was reduced in TL mice with insulin stimulation compared with the T group. Akt phosphorylation was not affected by exercise but was lower in the CL group compared with the other groups. Leucine supplementation increased mTOR phosphorylation at basal conditions, whereas exercise reduced it in the presence of insulin, despite no alterations in protein synthesis. In trained groups, the total FoxO3a protein content and the mRNA for the specific isoforms E2 and E3 ligases were reduced. In conclusion, leucine supplementation did not potentiate the effects of endurance training on protein turnover, and it also reduced its positive effects on glucose homeostasis. PMID:25575490

  17. High-dose green tea polyphenol intake decreases CYP3A expression in a liver-specific manner with increases in blood substrate drug concentrations.

    PubMed

    Ikarashi, Nobutomo; Ogawa, Sosuke; Hirobe, Ryuta; Kusunoki, Yoshiki; Kon, Risako; Ochiai, Wataru; Sugiyama, Kiyoshi

    2016-06-30

    In recent years, the intake of functional foods containing high-doses of green tea polyphenols (GP) has been increasing. In this study, the long-term safety of high-dose GP was assessed from a pharmacokinetic point of view by focusing on the drug-metabolizing enzyme, cytochrome P450 (CYP). Mice were fed a diet containing 3% GP for 4weeks, and the CYP expression levels and activity were determined. The GP-treated group showed a significant decrease in the hepatic CYP3A and an increase in the hepatic CYP2C expression compared with the control group. CYP1A, CYP2D, and CYP2E expression were not different between the GP-treated and the control groups. In the small intestine, there were no differences in the CYP3A protein levels between the groups. The increase in the plasma triazolam concentration in the GP-treated group was observed. Although no changes were found in the hepatic CYP3A levels in mice receiving a diet containing 0.1% GP for 4weeks, a significant decrease was seen in the hepatic CYP3A level in mice receiving a diet containing 3% GP for only 1week. This study revealed that the intake of a high-dose GP results in a liver-specific decrease in the CYP3A expression level. The results also indicated that the effects of GP on CYP3A were not observed following the intake of a low-dose GP. In the future, caution should be taken in cases when functional foods containing a high-dose GP are concomitantly consumed with a CYP3A substrate drug. PMID:27130545

  18. A nuclear factor containing the leucine-rich repeats expressed in murine cerebellar neurons.

    PubMed Central

    Matsuoka, K; Taoka, M; Satozawa, N; Nakayama, H; Ichimura, T; Takahashi, N; Yamakuni, T; Song, S Y; Isobe, T

    1994-01-01

    A nuclear protein, termed leucine-rich acidic nuclear protein (LANP), has been isolated from among rat cerebellar proteins whose expression was transiently increased during an early stage of postnatal development. The amino acid sequence, deduced from its cDNA, showed that LANP contains 247 amino acids consisting of two distinct structural domains: the N-terminal domain characterized by "leucine-rich repeat," which is found in many eukaryotic proteins and which potentially functions in mediating protein-protein interactions, and the C-terminal domain characterized by a cluster of acidic amino acids with a putative nuclear localization signal. Immunohistochemical study using an antibody against LANP revealed that the protein is localized mainly in nuclei of Purkinje cells. In the rat cerebellum on postnatal day 7, LANP mRNA was expressed moderately in the external granule and Purkinje cells and weakly in the internal granule cells. The expression in these cells, especially in Purkinje cells, increased in the second postnatal week and thereafter decreased to an adult level. The structural characteristics, localization, and the stage- and cell type-specific expression suggest a potential role of LANP in a signal transduction pathway that directs differentiation of cerebellar neurons. Images PMID:7937870

  19. Transcription attenuation in Salmonella typhimurium: the significance of rare leucine codons in the leu leader.

    PubMed Central

    Carter, P W; Bartkus, J M; Calvo, J M

    1986-01-01

    The leucine operon of Salmonella typhimurium is controlled by a transcription attenuation mechanism. Four adjacent leucine codons within a 160-nucleotide leu leader RNA are thought to play a central role in this mechanism. Three of the four codons are CUA, a rarely used leucine codon within enteric bacteria. To determine whether the nature of the leucine codon affects the regulation of the leucine operon, we used oligonucleotide-directed mutagenesis to first convert one CUA of the leader to CUG and then convert all three CUA codons to CUG. CUG is the most frequently used leucine codon in enteric bacteria. A mutant having (CUA)2CUGCUC in place of (CUA)3CUC has an altered response to leucine limitation, requiring a slightly higher degree of limitation to effect derepression. Changing (CUA)3CUC to (CUG)3CUC has more dramatic effects upon operon expression. First, the basal level of expression is lowered to the point that the mutant grows more slowly than the parent in a minimal medium lacking leucine. Second, the response of the mutant to a leucine limitation is dramatically altered such that even a strong limitation elicits only a modest degree of derepression. If the mutant is grown under conditions of leucyl-tRNA limitation rather than leucine limitation, complete derepression can be achieved, but only at a much higher degree of limitation than for the wild-type operon. These results provide a clear-cut example of codon usage having a dramatic effect upon gene expression. PMID:3534884

  20. A leucine-rich diet and exercise affect the biomechanical characteristics of the digital flexor tendon in rats after nutritional recovery.

    PubMed

    Barbosa, Alexandre Wesley Carvalho; Benevides, Gustavo Pereira; Alferes, Leda Maria Totti; Salomão, Emilianne Miguel; Gomes-Marcondes, Maria Cristina Cintra; Gomes, Laurecir

    2012-01-01

    An increase in the capacity of athletic performance depends on adequate nutrition, which ensures optimal function of the musculoskeletal system, including tendon stability. However, little is known about the status of tendons and extracellular matrix modifications during malnutrition and nutritional recovery when leucine is used in response to exercise conditioning. The purpose of this study was to evaluate the collagen content and biomechanical aspects of the deep digital flexor tendon (DDFT) in malnourished rats submitted to nutritional recovery (control diet or leucine-rich diet) and aerobic physical activity. After 60 days of undernourishment (6% protein diet), the malnourished rats were subsequently nutritionally recovered with a control diet or leucine-rich diet and trained or not (swimming, without overload) for 5 weeks. The biomechanical analysis and quantification of hydroxyproline were assessed in the DDFT in all experimental groups. The leucine-rich diet increased hydroxyproline content in the tension region, independently of the training. In the compression region, hydroxyproline content was higher in the malnourished and leucine-trained groups. Biomechanical analysis showed a lower load in the malnourished and all-trained groups. The lowest stress was observed with control-trained animals. The nutritional-recovered groups showed higher strain values corresponding to control group, while the lowest values were observed in malnourished and trained groups. The results suggest that a leucine-rich diet stimulates collagen synthesis of the DDFT, especially when in combination with physical exercise, and seems to determine the increase of resistance and the biomechanical characteristics of tendons. PMID:21107621

  1. Exposure to low UVA doses increases KatA and KatB catalase activities, and confers cross-protection against subsequent oxidative injuries in Pseudomonas aeruginosa.

    PubMed

    Pezzoni, Magdalena; Tribelli, Paula M; Pizarro, Ramón A; López, Nancy I; Costa, Cristina S

    2016-05-01

    Solar UVA radiation is one of the main environmental stress factors for Pseudomonas aeruginosa. Exposure to high UVA doses produces lethal effects by the action of the reactive oxygen species (ROS) it generates. P. aeruginosa has several enzymes, including KatA and KatB catalases, which provide detoxification of ROS. We have previously demonstrated that KatA is essential in defending P. aeruginosa against high UVA doses. In order to analyse the mechanisms involved in the adaptation of this micro-organism to UVA, we investigated the effect of exposure to low UVA doses on KatA and KatB activities, and the physiological consequences. Exposure to UVA induced total catalase activity; assays with non-denaturing polyacrylamide gels showed that both KatA and KatB activities were increased by radiation. This regulation occurred at the transcriptional level and depended, at least partly, on the increase in H2O2 levels. We demonstrated that exposure to low UVA produced a protective effect against subsequent lethal doses of UVA, sodium hypochlorite and H2O2. Protection against lethal UVA depends on katA, whilst protection against sodium hypochlorite depends on katB, demonstrating that different mechanisms are involved in the defence against these oxidative agents, although both genes can be involved in the global cellular response. Conversely, protection against lethal doses of H2O2 could depend on induction of both genes and/or (an)other defensive factor(s). A better understanding of the adaptive response of P. aeruginosa to UVA is relevant from an ecological standpoint and for improving disinfection strategies that employ UVA or solar irradiation. PMID:26940049

  2. ANTIDEPRESSANT-LIKE EFFECTS OF LOW KETAMINE DOSE IS ASSOCIATED WITH INCREASED HIPPOCAMPAL AMPA/NMDA RECEPTOR DENSITY RATIO IN FEMALE WISTAR-KYOTO RATS

    PubMed Central

    Tizabi, Yousef; Bhatti, Babur H; Manaye, Kebreten F; Das, Jharna R; Akinfiresoye, Luli

    2012-01-01

    Preclinical as well as limited clinical studies indicate that ketamine, a non-competitive glutamate NMDA receptor antagonist, may exert a quick and prolonged antidepressant effect. It has been postulated that ketamine action is due to inhibition of NMDA and stimulation of AMPA receptors. Here, we sought to determine whether ketamine would exert antidepressant effects in Wistar-Kyoto (WKY) rats, a putative animal model of depression and whether this effect would be associated with changes in AMPA/NMDA receptor densities in the hippocampus. Adult female WKY rats and their control Wistar rats were subjected to acute and chronic ketamine doses and their locomotor activity (LMA) and immobility in the forced swim test (FST) were evaluated. Hippocampal AMPA and NMDA receptor densities were also measured following a chronic ketamine dose. Ketamine, both acutely (0.5–5.0 mg/kg ip) and chronically (0.5–2.5 mg/kg daily for 10 days) resulted in a dose-dependent and prolonged decrease in immobility in the FST in WKY rats only, suggesting an antidepressant-like effect in this model. Chronic treatment with an effective dose of ketamine also resulted in an increase in AMPA/NMDA receptor density ratio in the hippocampus of WKY rats. LMA was not affected by any ketamine treatment in either strain. These results indicate a rapid and lasting antidepressant-like effect of a low ketamine dose in WKY rat model of depression. Moreover, the increase in AMPA/NMDA receptor density in hippocampus could be a contributory factor to behavioral effects of ketamine. These findings suggest potential therapeutic benefit in simultaneous reduction of central NMDA and elevation of AMPA receptor function in treatment of depression. PMID:22521815

  3. Accelerated Onset of Action and Increased Tolerability in Treating Acne With a Fixed-Dose Combination Gel.

    PubMed

    Friedman, Adam; Waite, Kim; Brandt, Staci; Meckfessel, Matthew H

    2016-02-01

    Nonadherence to topical acne therapies is a major contributing factor to poor treatment outcomes. Multiple contributing factors have been identified, including a lack of perceived efficacy and fear of side effects. A fixed-dose combination gel of adapalene/benzoyl peroxide gel, 0.1%/2.5% (A-BPO) is an efficacious and safe treatment for a range of acne severities in patients as young as 9 years old. A meta-analysis of 14 clinical studies involving A-BPO was conducted to assess the 4 week efficacy and overall tolerability of this treatment. Over 2,300 subjects were included in the analysis. Mean total, inflammatory, and non-inflammatory lesion counts decreased at 4 weeks by 40.8%, 46.2%, and 37.5%, respectively. Worst post-baseline tolerability scores for stinging/burning, dryness, scaling, and erythema were none or mild for a majority of subjects. The result of this meta-analysis add to the body of literature supporting the use of A-BPO in a variety of acne patients and shows that A-BPO provides meaningful clinical results within 4 weeks and will be well-tolerated for a majority of patients. With a demonstrable quick onset of action and high tolerability, A-BPO may improve adherence, and ultimately treatment outcomes, by addressing factors that contribute to nonadherence.

    J Drugs Dermatol. 2016;15(2):231-236. PMID:26885793

  4. The Role of Leucine-Rich Repeat Containing Protein 10 (LRRC10) in Dilated Cardiomyopathy

    PubMed Central

    Brody, Matthew J.; Lee, Youngsook

    2016-01-01

    Leucine-rich repeat containing protein 10 (LRRC10) is a cardiomyocyte-specific member of the Leucine-rich repeat containing (LRRC) protein superfamily with critical roles in cardiac function and disease pathogenesis. Recent studies have identified LRRC10 mutations in human idiopathic dilated cardiomyopathy (DCM) and Lrrc10 homozygous knockout mice develop DCM, strongly linking LRRC10 to the molecular etiology of DCM. LRRC10 localizes to the dyad region in cardiomyocytes where it can interact with actin and α-actinin at the Z-disc and associate with T-tubule components. Indeed, this region is becoming increasingly recognized as a signaling center in cardiomyocytes, not only for calcium cycling, excitation-contraction coupling, and calcium-sensitive hypertrophic signaling, but also as a nodal signaling hub where the myocyte can sense and respond to mechanical stress. Disruption of a wide range of critical structural and signaling molecules in cardiomyocytes confers susceptibility to cardiomyopathies in addition to the more classically studied mutations in sarcomeric proteins. However, the molecular mechanisms underlying DCM remain unclear. Here, we review what is known about the cardiomyocyte functions of LRRC10, lessons learned about LRRC10 and DCM from the Lrrc10 knockout mouse model, and discuss ongoing efforts to elucidate molecular mechanisms whereby mutation or absence of LRRC10 mediates cardiac disease. PMID:27536250

  5. Complex coacervates obtained from peptide leucine and gum arabic: formation and characterization.

    PubMed

    Gulão, Eliana da S; de Souza, Clitor J F; Andrade, Cristina T; Garcia-Rojas, Edwin E

    2016-03-01

    In this study, interactions between polypeptide-leucine (0.2% w/w) and gum arabic (0.03, 0.06, 0.09, 0.12, and 0.15% w/w) were examined at concentrations of NaCl (0, 0.01, 0.25, 0.3, 0.5mol/l) and at different pH values (from 1.0 to 12.0). Formation of insoluble complex coacervates was highest at pH 4.0. At pH 2.0, which is the pKa of the gum Arabic, the dissociation of precipitate occurred. The pHØ2 positively shifted with the addition of higher concentrations of salt. Samples containing 0.2% PL and 0.03% GA and no salt had higher turbidity and increased formation of precipitates showing greater turbidity and particle sizes. The Fourier transform infrared spectroscopy confirms the complex coacervate formation of leucine and gum arabic, and rheological measurements suggest the elastic behavior of 0.2% PL and 0.03% GA complex. Overall, the study suggests that complex coacervates of PLs could be one feasible ways of incorporating amino acids in food products. PMID:26471607

  6. The Role of Leucine-Rich Repeat Containing Protein 10 (LRRC10) in Dilated Cardiomyopathy.

    PubMed

    Brody, Matthew J; Lee, Youngsook

    2016-01-01

    Leucine-rich repeat containing protein 10 (LRRC10) is a cardiomyocyte-specific member of the Leucine-rich repeat containing (LRRC) protein superfamily with critical roles in cardiac function and disease pathogenesis. Recent studies have identified LRRC10 mutations in human idiopathic dilated cardiomyopathy (DCM) and Lrrc10 homozygous knockout mice develop DCM, strongly linking LRRC10 to the molecular etiology of DCM. LRRC10 localizes to the dyad region in cardiomyocytes where it can interact with actin and α-actinin at the Z-disc and associate with T-tubule components. Indeed, this region is becoming increasingly recognized as a signaling center in cardiomyocytes, not only for calcium cycling, excitation-contraction coupling, and calcium-sensitive hypertrophic signaling, but also as a nodal signaling hub where the myocyte can sense and respond to mechanical stress. Disruption of a wide range of critical structural and signaling molecules in cardiomyocytes confers susceptibility to cardiomyopathies in addition to the more classically studied mutations in sarcomeric proteins. However, the molecular mechanisms underlying DCM remain unclear. Here, we review what is known about the cardiomyocyte functions of LRRC10, lessons learned about LRRC10 and DCM from the Lrrc10 knockout mouse model, and discuss ongoing efforts to elucidate molecular mechanisms whereby mutation or absence of LRRC10 mediates cardiac disease. PMID:27536250

  7. Activation of mTORC1 by leucine is potentiated by branched-chain amino acids and even more so by essential amino acids following resistance exercise.

    PubMed

    Moberg, Marcus; Apró, William; Ekblom, Björn; van Hall, Gerrit; Holmberg, Hans-Christer; Blomstrand, Eva

    2016-06-01

    Protein synthesis is stimulated by resistance exercise and intake of amino acids, in particular leucine. Moreover, activation of mammalian target of rapamycin complex 1 (mTORC1) signaling by leucine is potentiated by the presence of other essential amino acids (EAA). However, the contribution of the branched-chain amino acids (BCAA) to this effect is yet unknown. Here we compare the stimulatory role of leucine, BCAA, and EAA ingestion on anabolic signaling following exercise. Accordingly, eight trained volunteers completed four sessions of resistance exercise during which they ingested either placebo, leucine, BCAA, or EAA (including the BCAA) in random order. Muscle biopsies were taken at rest, immediately after exercise, and following 90 and 180 min of recovery. Following 90 min of recovery the activity of S6 kinase 1 (S6K1) was greater than at rest in all four trials (Placebo<Leucineincrease in the EAA trial. At this same time point, phosphorylation of eukaryotic translation initiation factor 4E (eIF4E)-binding protein 1 (4E-BP1) at Thr(37/46) was unaffected by supplementation, while that of Thr(46) alone exhibited a pattern similar to that of S6K1, being 18% higher with EAA than BCAA. However, after 180 min of recovery this difference between EAA and BCAA had disappeared, although with both these supplements the increases were still higher than with leucine (40%, P < 0.05) and placebo (100%, P < 0.05). In summary, EAA ingestion appears to stimulate translation initiation more effectively than the other supplements, although the results also suggest that this effect is primarily attributable to the BCAA. PMID:27053525

  8. Enhanced production of branched-chain amino acids by Gluconacetobacter europaeus with a specific regional deletion in a leucine responsive regulator.

    PubMed

    Akasaka, Naoki; Ishii, Yuri; Hidese, Ryota; Sakoda, Hisao; Fujiwara, Shinsuke

    2014-12-01

    Vinegar with increased amounts of branched-chain amino acids (BCAAs; valine, leucine and isoleucine) is favorable for human health as BCAAs decrease diet-induced obesity and hyperglycemia. To construct Gluconacetobacter europaeus which produces BCAAs, leucine responsive regulator (GeLrp) is focused and two Gelrp mutants were constructed. Wild-type KGMA0119 didn't produce significant amount of valine (0.13 mM) and leucine (0 mM) and strain KGMA7110 which lacks complete Gelrp accumulated valine (0.48 mM) and leucine (0.11 mM) but showed impaired growth, and it was fully restored in the presence of essential amino acids. Strain KGMA7203 was then constructed with a nonsense mutation at codon Trp132 in the Gelrp, which leads a specific deletion at an estimated ligand-sensing region in the C-terminal domain. KGMA7203 produced greater quantities of valine (0.80 mM) and leucine (0.26 mM) and showed the same growth characteristics as KGMA0119. mRNA levels of BCAAs biosynthesis genes (ilvI and ilvC) and probable BCAAs efflux pump (leuE) were determined by quantitative reverse-transcription PCR. Expression rates of ilvI and ilvC in the two Gelrp disruptants were greater than those in KGMA0119. leuE was highly expressed in KGMA7110 only, suggesting that the accumulation in KGMA7110 culture was caused by increased expression of the biosynthesis genes and abnormal enhanced export of amino acids resulting in impaired cell growth. In contrast, KGMA7203 would achieve the high level production through enhanced expression of the biosynthesis genes without enhancing that for the efflux pump. KGMA7203 was considered advantageous for production of vinegar with higher amounts of valine and leucine. PMID:24985571

  9. Crystal Engineering of l-Alanine with l-Leucine Additive using Metal-Assisted and Microwave-Accelerated Evaporative Crystallization

    PubMed Central

    2015-01-01

    In this work, we demonstrated that the change in the morphology of l-alanine crystals can be controlled with the addition of l-leucine using the metal-assisted and microwave accelerated evaporative crystallization (MA-MAEC) technique. Crystallization experiments, where an increasing stoichiometric amount of l-leucine is added to initial l-alanine solutions, were carried out on circular poly(methyl methacrylate) (PMMA) disks modified with a 21-well capacity silicon isolator and silver nanoparticle films using microwave heating (MA-MAEC) and at room temperature (control experiments). The use of the MA-MAEC technique afforded for the growth of l-alanine crystals with different morphologies up to ∼10-fold faster than those grown at room temperature. In addition, the length of l-alanine crystals was systematically increased from ∼380 to ∼2000 μm using the MA-MAEC technique. Optical microscope images revealed that the shape of l-alanine crystals was changed from tetragonal shape (without l-leucine additive) to more elongated and wire-like structures with the addition of the l-leucine additive. Further characterization of l-alanine crystals was undertaken by Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy and powder X-ray diffraction (PXRD) measurements. In order to elucidate the growth mechanism of l-alanine crystals, theoretical simulations of l-alanine’s morphology with and without l-leucine additive were carried out using Materials Studio software in conjunction with our experimental data. Theoretical simulations revealed that the growth of l-alanine’s {011} and {120} crystal faces were inhibited due to the incorporation of l-leucine into these crystal faces in selected positions. PMID:24839404

  10. Leucine leucine-37 uses formyl peptide receptor-like 1 to activate signal transduction pathways, stimulate oncogenic gene expression, and enhance the invasiveness of ovarian cancer cells.

    PubMed

    Coffelt, Seth B; Tomchuck, Suzanne L; Zwezdaryk, Kevin J; Danka, Elizabeth S; Scandurro, Aline B

    2009-06-01

    Emerging evidence suggests that the antimicrobial peptide, leucine leucine-37 (LL-37), could play a role in the progression of solid tumors. LL-37 is expressed as the COOH terminus of human cationic antimicrobial protein-18 (hCAP-18) in ovarian, breast, and lung cancers. Previous studies have shown that the addition of LL-37 to various cancer cell lines in vitro stimulates proliferation, migration, and invasion. Similarly, overexpression of hCAP-18/LL-37 in vivo accelerates tumor growth. However, the receptor or receptors through which these processes are mediated have not been thoroughly examined. In the present study, expression of formyl peptide receptor-like 1 (FPRL1) was confirmed on ovarian cancer cells. Proliferation assays indicated that LL-37 does not signal through a G protein-coupled receptor, such as FPRL1, to promote cancer cell growth. By contrast, FPRL1 was required for LL-37-induced invasion through Matrigel. The peptide stimulated mitogen-activated protein kinase and Janus-activated kinase/signal transducers and activators of transcription signaling cascades and led to the significant activation of several transcription factors, through both FPRL1-dependent and FPRL1-independent pathways. Likewise, expression of some LL-37-stimulated genes was attenuated by the inhibition of FPRL1. Increased expression of CXCL10, EGF, and PDGF-BB as well as other soluble factors was confirmed from conditioned medium of LL-37-treated cells. Taken together, these data suggest that LL-37 potentiates a more aggressive behavior from ovarian cancer cells through its interaction with FPRL1. PMID:19491199

  11. Leucine Leucine-37 Uses Formyl Peptide Receptor–Like 1 to Activate Signal Transduction Pathways, Stimulate Oncogenic Gene Expression, and Enhance the Invasiveness of Ovarian Cancer Cells

    PubMed Central

    Coffelt, Seth B.; Tomchuck, Suzanne L.; Zwezdaryk, Kevin J.; Danka, Elizabeth S.; Scandurro, Aline B.

    2009-01-01

    Emerging evidence suggests that the antimicrobial peptide, leucine leucine-37 (LL-37), could play a role in the progression of solid tumors. LL-37 is expressed as the COOH terminus of human cationic antimicrobial protein-18 (hCAP-18) in ovarian, breast, and lung cancers. Previous studies have shown that the addition of LL-37 to various cancer cell lines in vitro stimulates proliferation, migration, and invasion. Similarly, overexpression of hCAP-18/LL-37 in vivo accelerates tumor growth. However, the receptor or receptors through which these processes are mediated have not been thoroughly examined. In the present study, expression of formyl peptide receptor–like 1 (FPRL1) was confirmed on ovarian cancer cells. Proliferation assays indicated that LL-37 does not signal through a G protein–coupled receptor, such as FPRL1, to promote cancer cell growth. By contrast, FPRL1 was required for LL-37–induced invasion through Matrigel. The peptide stimulated mitogen-activated protein kinase and Janus-activated kinase/signal transducers and activators of transcription signaling cascades and led to the significant activation of several transcription factors, through both FPRL1-dependent and FPRL1-independent pathways. Likewise, expression of some LL-37–stimulated genes was attenuated by the inhibition of FPRL1. Increased expression of CXCL10, EGF, and PDGF-BB as well as other soluble factors was confirmed from conditioned medium of LL-37–treated cells. Taken together, these data suggest that LL-37 potentiates a more aggressive behavior from ovarian cancer cells through its interaction with FPRL1. PMID:19491199

  12. Exponentially increasing incidences of cutaneous malignant melanoma in Europe correlate with low personal annual UV doses and suggests 2 major risk factors

    PubMed Central

    Merrill, Stephen J; Ashrafi, Samira; Subramanian, Madhan; Godar, Dianne E

    2015-01-01

    For several decades the incidence of cutaneous malignant melanoma (CMM) steadily increased in fair-skinned, indoor-working people around the world. Scientists think poor tanning ability resulting in sunburns initiate CMM, but they do not understand why the incidence continues to increase despite the increased use of sunscreens and formulations offering more protection. This paradox, along with lower incidences of CMM in outdoor workers, although they have significantly higher annual UV doses than indoor workers have, perplexes scientists. We found a temporal exponential increase in the CMM incidence indicating second-order reaction kinetics revealing the existence of 2 major risk factors. From epidemiology studies, we know one major risk factor for getting CMM is poor tanning ability and we now propose the other major risk factor may be the Human Papilloma Virus (HPV) because clinicians find β HPVs in over half the biopsies. Moreover, we uncovered yet another paradox; the increasing CMM incidences significantly correlate with decreasing personal annual UV dose, a proxy for low vitamin D3 levels. We also discovered the incidence of CMM significantly increased with decreasing personal annual UV dose from 1960, when it was almost insignificant, to 2000. UV and other DNA-damaging agents can activate viruses, and UV-induced cytokines can hide HPV from immune surveillance, which may explain why CMM also occurs in anatomical locations where the sun does not shine. Thus, we propose the 2 major risk factors for getting CMM are intermittent UV exposures that result in low cutaneous levels of vitamin D3 and possibly viral infection. PMID:26413188

  13. Role of renal D-amino-acid oxidase in pharmacokinetics of D-leucine.

    PubMed

    Hasegawa, Hiroshi; Matsukawa, Takehisa; Shinohara, Yoshihiko; Konno, Ryuichi; Hashimoto, Takao

    2004-07-01

    d-Amino acids are now recognized to be widely present in mammals. Renal d-amino-acid oxidase (DAO) is associated with conversion of d-amino acids to the corresponding alpha-keto acids, but its contribution in vivo is poorly understood because the alpha-keto acids and/or l-amino acids formed are indistinguishable from endogenous compounds. First, we examined whether DAO is indispensable for conversion of d-amino acids to their alpha-keto acids by using the stable isotope tracer technique. After a bolus intravenous administration of d-[(2)H(7)]leucine to mutant mice lacking DAO activity (ddY/DAO(-)) and normal mice (ddY/DAO(+)), elimination of d-[(2)H(7)]leucine and formation of alpha-[(2)H(7)]ketoisocaproic acid ([(2)H(7)]KIC) and l-[(2)H(7)]leucine in plasma were determined. The ddY/DAO(-) mice, in contrast to ddY/DAO(+) mice, failed to convert d-[(2)H(7)]leucine to [(2)H(7)]KIC and l-[(2)H(7)]leucine. This result clearly revealed that DAO was indispensable for the process of chiral inversion of d-leucine. We further investigated the effect of renal mass reduction by partial nephrectomy on elimination of d-[(2)H(7)]leucine and formation of [(2)H(7)]KIC and l-[(2)H(7)]leucine. Renal mass reduction slowed down the elimination of d-[(2)H(7)]leucine. The fraction of conversion of d-[(2)H(7)]leucine to [(2)H(7)]KIC in sham-operated rats was 0.77, whereas that in five-sixths-nephrectomized rats was 0.25. The elimination behavior of d-[(2)H(7)]leucine observed in rats suggested that kidney was the principal organ responsible for converting d-leucine to KIC. PMID:15026304

  14. Knockout of leucine aminopeptidase in Toxoplasma gondii using CRISPR/Cas9.

    PubMed

    Zheng, Jun; Jia, Honglin; Zheng, Yonghui

    2015-02-01

    Leucine aminopeptidases of the M17 peptidase family represent ideal drug targets for therapies directed against the pathogens Plasmodium, Babesia and Trypanosoma. Previously, we characterised Toxoplasma gondii leucine aminopeptidase and demonstrated its role in regulating the levels of free amino acids. In this study, we evaluated the potential of T. gondii leucine aminopeptidase as a drug target in T. gondii by a knockout method. Existing knockout methods for T. gondii have many drawbacks; therefore, we developed a new technique that takes advantage of the CRISPR/Cas9 system. We first chose a Cas9 target site in the gene encoding T. gondii leucine aminopeptidase and then constructed a knockout vector containing Cas9 and the single guide RNA. After transfection, single tachyzoites were cloned in 96-well plates by limiting dilution. Two transfected strains derived from a single clone were cultured in Vero cells, and then subjected to expression analysis by western blotting. The phenotypic analysis revealed that knockout of T. gondii leucine aminopeptidase resulted in inhibition of attachment/invasion and replication; both the growth and attachment/invasion capacity of knockout parasites were restored by complementation with a synonymously substituted allele of T. gondii leucine aminopeptidase. Mouse experiments demonstrated that T. gondii leucine aminopeptidase knockout somewhat reduced the pathogenicity of T. gondii. An enzymatic activity assay showed that T. gondii leucine aminopeptidase knockout reduced the processing of a leucine aminopeptidase-specific substrate in T. gondii. The absence of leucine aminopeptidase activity could be slightly compensated for in T. gondii. Overall, T. gondii leucine aminopeptidase knockout influenced the growth of T. gondii, but did not completely block parasite development, virulence or enzymatic activity. Therefore, we conclude that leucine aminopeptidase would be useful only as an adjunctive drug target in T. gondii. PMID

  15. Has the sensitivity of soybean cultivars to ozone pollution increased with time? An analysis of published dose-response data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rising trend in concentrations of ground-level ozone (O3) – a common air pollutant and phytotoxin – currently being experienced in some world regions represents a threat to agricultural yield. Soybean (Glycine max (L.) Merr.) is an O3-sensitive crop species, and is experiencing increasing globa...

  16. Histochemistry of leucine aminonaphthylamidase (LAN) in rainbow trout (Salmo gairdneri)

    USGS Publications Warehouse

    Bouck, Gerald R.

    1979-01-01

    The histochemistry of leucine aminonaphthylamidase (LAN) was studied in frozen tissue sections of rainbow trout both in yearling and adult fish. Age of fish had relatively little effect upon the results. The most intense LAN color production was in epithelial cells of midgut, pyloric ceca, hindgut, and in some segments of kidney tubules. Lower levels of LAN were evident in liver cells of Kupffer, and still lower or slight levels of LAN activity were found in blood cells, muscle, nerve, connective tissue, gonad, and pancreas. The results indicate that LAN might be useful in assessing histotoxicity to LAN-rich areas of the body.

  17. Effects of Increasing Doses of UV-B on Main Phenolic Acids Content, Antioxidant Activity and Estimated Biomass in Lavandin (Lavandula x intermedia).

    PubMed

    Usano-Alemany, Jaime; Panjai, Lachinee

    2015-07-01

    Lavandin is a well-known aromatic plant cultivated mainly for its valuable essential oil. Nonetheless, little attention has been paid so far to the quantification of other natural products such as polyphenols. Accordingly, we examined the effect of increasing doses of UV-B radiation on the main phenolic content, antioxidant activity and estimated biomass of one year old lavandin pots compared with pots grown outdoors. Significantly higher total phenolic content and concentration of main polyphenols have been found in outdoor plants. Rosmarinic acid has been described as the major phenolic compound in methanolic extracts (max. 25.9 ± 9.7 mg/g(-1) DW). Furthermore, we found that increasing doses of UV-B promote the plant growth of this species as well as the accumulation of phenolic compounds although with less antioxidant capacity in scavenging DPPH radicals. On the other hand, our results showed a remarkable variability among individual plants regarding the content of major phenolic acids. The application of UV-B doses during plant growth could be a method to promote biomass in this species along with the promotion of higher content of valuable secondary metabolites. PMID:26411027

  18. Lack of glucocorticoid-induced leucine zipper (GILZ) deregulates B-cell survival and results in B-cell lymphocytosis in mice

    PubMed Central

    Bruscoli, Stefano; Biagioli, Michele; Sorcini, Daniele; Frammartino, Tiziana; Cimino, Monica; Sportoletti, Paolo; Mazzon, Emanuela; Bereshchenko, Oxana

    2015-01-01

    Glucocorticoids (GC) are widely used as antiinflammatory/immunosuppressive drugs and antitumor agents in several types of lymphoma and leukemia. Therapeutic doses of GC induce growth-suppressive and cytotoxic effects on various leukocytes including B cells. Molecular mechanisms of GC action include induction of GC target genes. Glucocorticoid-induced leucine zipper (GILZ) is a rapidly, potently, and invariably GC-induced gene. It mediates a number of GC effects, such as control of cell proliferation, differentiation, and apoptosis. Here we show that deletion of GILZ in mice leads to an accumulation of B lymphocytes in the bone marrow, blood, and lymphoid tissues. Gilz knockout (KO) mice develop a progressive nonlethal B lymphocytosis, with expansion of B220+ cells in the bone marrow and in the periphery, dependent on increased B-cell survival. Decreased B-cell apoptosis in mice lacking GILZ correlates with increased NF-κB transcriptional activity and Bcl-2 expression. B cell–specific gilz KO mice confirmed that the effect of GILZ deletion is B-cell self-intrinsic. These results establish GILZ as an important regulator of B-cell survival and suggest that the deregulation of GILZ expression could be implicated in the pathogenesis of B-cell disorders. PMID:26276664

  19. The thermodynamic characteristics of complex formation between calcium ions and L-leucine in aqueous solution

    NASA Astrophysics Data System (ADS)

    Kurochkin, V. Yu.; Chernikov, V. V.; Orlova, T. D.

    2011-04-01

    Complex formation of L-leucine with calcium ions in aqueous solution was studied by potentiometric titration at 298.15 K and ionic strength values I = 0.5, 1.0, and 1.5 (KNO3). The formation of the CaL+ and CaHL2+ complex particles was established and their stability constants were determined. The enthalpies of protolytic equilibria of leucine and formation of calcium ion complexes with leucine were determined calorimetrically at 298.15 K and I = 0.5 (KNO3). The thermodynamic characteristics of complex formation between calcium ions and L-leucine were calculated.

  20. Acetone formation in the Vibrio family: a new pathway for bacterial leucine catabolism.

    PubMed

    Nemecek-Marshall, M; Wojciechowski, C; Wagner, W P; Fall, R

    1999-12-01

    There is current interest in biological sources of acetone, a volatile organic compound that impacts atmospheric chemistry. Here, we determined that leucine-dependent acetone formation is widespread in the Vibrionaceae. Sixteen Vibrio isolates, two Listonella species, and two Photobacterium angustum isolates produced acetone in the presence of L-leucine. Shewanella isolates produced much less acetone. Growth of Vibrio splendidus and P. angustum in a fermentor with controlled aeration revealed that acetone was produced after a lag in late logarithmic or stationary phase of growth, depending on the medium, and was not derived from acetoacetate by nonenzymatic decarboxylation in the medium. L-Leucine, but not D-leucine, was converted to acetone with a stoichiometry of approximately 0.61 mol of acetone per mol of L-leucine. Testing various potential leucine catabolites as precursors of acetone showed that only alpha-ketoisocaproate was efficiently converted by whole cells to acetone. Acetone production was blocked by a nitrogen atmosphere but not by electron transport inhibitors, suggesting that an oxygen-dependent reaction is required for leucine catabolism. Metabolic labeling with deuterated (isopropyl-d(7))-L-leucine revealed that the isopropyl carbons give rise to acetone with full retention of deuterium in each methyl group. These results suggest the operation of a new catabolic pathway for leucine in vibrios that is distinct from the 3-hydroxy-3-methylglutaryl-coenzyme A pathway seen in pseudomonads. PMID:10601206

  1. Leucine Transport in Cells Isolated from Cold-Hardened and Nonhardened Winter Rye 1

    PubMed Central

    Barran, Leslie R.; Singh, Jas

    1982-01-01

    The properties of the leucine transport systems of cells isolated from dark-grown cold-hardened and nonhardened winter rye (Secale cereale L. cv. Puma) epicotyls were remarkably similar. After 1 hour of incubation, leucine was accumulated in the cells 80- to 100-fold above that of the external medium, but the transported leucine was not metabolized. Approximately one-third of the accumulated leucine was present in the vacuole after 40 minutes of incubation. At 25°C, efflux of leucine from the vacuole was 6 to 10 times slower than it was from the cytoplasm, while at 5°C efflux from the cells was inhibited. The apparent Km and Vmax for leucine uptake for both types of cells were of the order of 20 to 60 micromolar and 0.5 to 1.3 nanomoles per minute per 106 cells. The pH and temperature optima for both types of cells were 5 and 25°C, respectively. The leucine transport system for these cells was relatively specific for amino acids lacking either bulky or charged groups on the amino acid side chains. Arrhenius plots for leucine uptake by hardened and nonhardened cells showed discontinuities at 13°C, and the energies of activation were similar. The results suggests that biochemical changes which occur in rye cells upon cold hardening did not result in an observable perturbation of the properties of the leucine transport system. PMID:16662298

  2. Long-term low-level laser therapy promotes an increase in maximal oxygen uptake and exercise performance in a dose-dependent manner in Wistar rats.

    PubMed

    Perini, Júlia Luiza; Hentschke, Vítor Scotta; Sonza, Anelise; Dal Lago, Pedro

    2016-02-01

    The use of low-level laser therapy (LLLT) represents a new intervention modality that has been explored to enhance exercise performance. The aim of this study was to evaluate the influence of LLLT (GaAIAs-850 nm) at different doses on VO2max and on exercise performance in rats. Male Wistar rats were divided into three groups: "placebo" rats (P-LLLT, n = 10), rats at a dose of 0.315 J per treatment point of LLLT (8.7 J/cm(2)-LLLT, n = 10), and rats at a dose of 2.205 J per treatment point of LLLT (61.2 J/cm(2)-LLLT, n = 10). The LLLT was applied bilaterally at the biceps femoris, gluteus, lateral and medial gastrocnemius, iliopsoas, and adductor longus muscles. One spot in each muscle belly was applied, with a sum of 12 spots in each rat, once a day, for 10 days. All animals performed the maximal exercise test (ET) at a metabolic treadmill for rats, with simultaneous gas analysis. The distance covered was measured during ET, before and after the conclusion of the LLLT protocol. The data were compared by a repeated measures two-way ANOVA followed by the Student-Newman-Keuls post hoc tests (p < .05). The 61.2 J/cm(2)-LLLT group increased VO2basal (~40 %), VO2max (~24 %), VCO2max (~17 %), and distance covered (~34 %) after LLLT application on the skeletal muscle. No significant results were found comparing before and after conditions for the studied variables considering P-LLLT and 8.7 J/cm(2)-LLLT groups. The LLLT promoted in a dose-dependent manner an increase in oxygen consumption uptake and a performance increment of male Wistar rats. PMID:26714977

  3. Comparative analysis of pharmacological treatments with N-acetyl-dl-leucine (Tanganil) and its two isomers (N-acetyl-L-leucine and N-acetyl-D-leucine) on vestibular compensation: Behavioral investigation in the cat.

    PubMed

    Tighilet, Brahim; Leonard, Jacques; Bernard-Demanze, Laurence; Lacour, Michel

    2015-12-15

    Head roll tilt, postural imbalance and spontaneous nystagmus are the main static vestibular deficits observed after an acute unilateral vestibular loss (UVL). In the UVL cat model, these deficits are fully compensated over 6 weeks as the result of central vestibular compensation. N-Acetyl-dl-leucine is a drug prescribed in clinical practice for the symptomatic treatment of acute UVL patients. The present study investigated the effects of N-acetyl-dl-leucine on the behavioral recovery after unilateral vestibular neurectomy (UVN) in the cat, and compared the effects of each of its two isomers N-acetyl-L-leucine and N-acetyl-D-leucine. Efficacy of these three drug treatments has been evaluated with respect to a placebo group (UVN+saline water) on the global sensorimotor activity (observation grids), the posture control (support surface measurement), the locomotor balance (maximum performance at the rotating beam test), and the spontaneous vestibular nystagmus (recorded in the light). Whatever the parameters tested, the behavioral recovery was strongly and significantly accelerated under pharmacological treatments with N-acetyl-dl-leucine and N-acetyl-L-leucine. In contrast, the N-acetyl-D-leucine isomer had no effect at all on the behavioral recovery, and animals of this group showed the same recovery profile as those receiving a placebo. It is concluded that the N-acetyl-L-leucine isomer is the active part of the racemate component since it induces a significant acceleration of the vestibular compensation process similar (and even better) to that observed under treatment with the racemate component only. PMID:26607469

  4. Effects of Leucin-Enkephalins on Surface Characteristics and Morphology of Model Membranes Composed of Raft-Forming Lipids.

    PubMed

    Tsanova, Asya; Jordanova, A; Lalchev, Z

    2016-06-01

    During the last decades opioid peptides, like enkephalins (Tyr-Gly-Gly-Phe-Met/Leu) are subject to extensive studies due to their antinociceptive action in organism. According to the membrane catalysis theory, in order to adopt a proper conformation for binding to their receptors, opioid peptides interact with the lipid phase of the membrane receptor surrounding. With this regard, the aim of the present work was to study the effects of synthetic leucine-enkephalin and leucine-enkephalinamide on surface characteristics and morphology of lipid monolayers, composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, sphingomyelin, and cholesterol alone and with their mixtures. The lipids were chosen to represent a model of a membrane raft, since it is known that G-protein-coupled receptors, including opioid receptors, are located preferably in membrane rafts. By using Langmuir's monolayer method, the change in surface pressure of the model membranes before and after the addition of the synthetic enkephalins was studied, and the compressional moduli of the lipids and lipid-peptides monolayers were determined. In addition, by Brewster angle microscopy, the surface morphology of the lipid monolayers alone and after the injection of both enkephalins was monitored. Our results showed that both leucine-enkephalins affected the lipid monolayers surface characteristics, and led to an increase in surface density of the mixed surface lipids/enkephalins films at loose lipid packing. This effect was more pronounced for the enkephalinamide, suggesting a different mechanism of interaction for the amidated enkephalin with the lipid phase, as compared to leucine-enkephalin. PMID:26661722

  5. GCN2 contributes to mTORC1 inhibition by leucine deprivation through an ATF4 independent mechanism.

    PubMed

    Averous, Julien; Lambert-Langlais, Sarah; Mesclon, Florent; Carraro, Valérie; Parry, Laurent; Jousse, Céline; Bruhat, Alain; Maurin, Anne-Catherine; Pierre, Philippe; Proud, Christopher G; Fafournoux, Pierre

    2016-01-01

    It is well known that the GCN2 and mTORC1 signaling pathways are regulated by amino acids and share common functions, in particular the control of translation. The regulation of GCN2 activity by amino acid availability relies on the capacity of GCN2 to sense the increased levels of uncharged tRNAs upon amino acid scarcity. In contrast, despite recent progress in the understanding of the regulation of mTORC1 by amino acids, key aspects of this process remain unsolved. In particular, while leucine is well known to be a potent regulator of mTORC1, the mechanisms by which this amino acid is sensed and control mTORC1 activity are not well defined. Our data establish that GCN2 is involved in the inhibition of mTORC1 upon leucine or arginine deprivation. However, the activation of GCN2 alone is not sufficient to inhibit mTORC1 activity, indicating that leucine and arginine exert regulation via additional mechanisms. While the mechanism by which GCN2 contributes to the initial step of mTORC1 inhibition involves the phosphorylation of eIF2α, we show that it is independent of the downstream transcription factor ATF4. These data point to a novel role for GCN2 and phosphorylation of eIF2α in the control of mTORC1 by certain amino acids. PMID:27297692

  6. GCN2 contributes to mTORC1 inhibition by leucine deprivation through an ATF4 independent mechanism

    PubMed Central

    Averous, Julien; Lambert-Langlais, Sarah; Mesclon, Florent; Carraro, Valérie; Parry, Laurent; Jousse, Céline; Bruhat, Alain; Maurin, Anne-Catherine; Pierre, Philippe; Proud, Christopher G.; Fafournoux, Pierre

    2016-01-01

    It is well known that the GCN2 and mTORC1 signaling pathways are regulated by amino acids and share common functions, in particular the control of translation. The regulation of GCN2 activity by amino acid availability relies on the capacity of GCN2 to sense the increased levels of uncharged tRNAs upon amino acid scarcity. In contrast, despite recent progress in the understanding of the regulation of mTORC1 by amino acids, key aspects of this process remain unsolved. In particular, while leucine is well known to be a potent regulator of mTORC1, the mechanisms by which this amino acid is sensed and control mTORC1 activity are not well defined. Our data establish that GCN2 is involved in the inhibition of mTORC1 upon leucine or arginine deprivation. However, the activation of GCN2 alone is not sufficient to inhibit mTORC1 activity, indicating that leucine and arginine exert regulation via additional mechanisms. While the mechanism by which GCN2 contributes to the initial step of mTORC1 inhibition involves the phosphorylation of eIF2α, we show that it is independent of the downstream transcription factor ATF4. These data point to a novel role for GCN2 and phosphorylation of eIF2α in the control of mTORC1 by certain amino acids. PMID:27297692

  7. LEUCINE-RICH AMELOGENIN PEPTIDE INDUCES OSTEOGENESIS IN MOUSE EMBRYONIC STEM CELLS

    PubMed Central

    Warotayanont, Rungnapa; Zhu, Danhong; Snead, Malcolm L.; Zhou, Yan

    2008-01-01

    Leucine-rich amelogenin peptide (LRAP), an alternatively spliced amelogenin protein, possesses a signaling property shown to induce osteogenic differentiation. In the current study, we detected LRAP expression during osteogenesis of wild-type (WT) embryonic stem (ES) cells and observed the absence of LRAP expression in amelogenin-null (KO) ES cells. We explored the signaling effect of LRAP on wild-type ES cells, and the ability of LRAP to rescue the impaired osteogenesis phenotype observed in KO ES cells. Our data indicate that LRAP treatment of WT and KO ES cells induces a significant increase in mineral matrix formation, and significant increases in bone sialoprotein and osterix gene expression. In addition, the amelogenin KO phenotype is partially rescued by the addition of exogenous LRAP. These data suggest a unique function of LRAP during ES cell differentiation along osteogenic lineage. PMID:18086559

  8. Sestrin regulation of TORC1: Is Sestrin a leucine sensor?

    PubMed

    Lee, Jun Hee; Cho, Uhn-Soo; Karin, Michael

    2016-01-01

    Sestrins are highly conserved, stress-inducible proteins that inhibit target of rapamycin complex 1 (TORC1) signaling. After their transcriptional induction, both vertebrate and invertebrate Sestrins turn on the adenosine monophosphate (AMP)-activated protein kinase (AMPK), which activates the tuberous sclerosis complex (TSC), a key inhibitor of TORC1 activation. However, Sestrin overexpression, on occasion, can result in TORC1 inhibition even in AMPK-deficient cells. This effect has been attributed to Sestrin's ability to bind the TORC1-regulating GATOR2 protein complex, which was postulated to control trafficking of TORC1 to lysosomes. How the binding of Sestrins to GATOR2 is regulated and how it contributes to TORC1 inhibition are unknown. New findings suggest that the amino acid leucine specifically disrupts the association of Sestrin2 with GATOR2, thus explaining how leucine and related amino acids stimulate TORC1 activity. We discuss whether and how these findings fit what has already been learned about Sestrin-mediated TORC1 inhibition from genetic studies conducted in fruit flies and mammals. PMID:27273098

  9. Increased Hypoxic Dose After Training at Low Altitude with 9h Per Night at 3000m Normobaric Hypoxia.

    PubMed

    Carr, Amelia J; Saunders, Philo U; Vallance, Brent S; Garvican-Lewis, Laura A; Gore, Christopher J

    2015-12-01

    This study examined effects of low altitude training and a live-high: train-low protocol (combining both natural and simulated modalities) on haemoglobin mass (Hbmass), maximum oxygen consumption (VO2max), time to exhaustion, and submaximal exercise measures. Eighteen elite-level race-walkers were assigned to one of two experimental groups; lowHH (low Hypobaric Hypoxia: continuous exposure to 1380 m for 21 consecutive days; n = 10) or a combined low altitude training and nightly Normobaric Hypoxia (lowHH+NHnight: living and training at 1380 m, plus 9 h.night(-1) at a simulated altitude of 3000 m using hypoxic tents; n = 8). A control group (CON; n = 10) lived and trained at 600 m. Measurement of Hbmass, time to exhaustion and VO2max was performed before and after the training intervention. Paired samples t-tests were used to assess absolute and percentage change pre and post-test differences within groups, and differences between groups were assessed using a one-way ANOVA with least significant difference post-hoc testing. Statistical significance was tested at p < 0.05. There was a 3.7% increase in Hbmass in lowHH+NHnight compared with CON (p = 0.02). In comparison to baseline, Hbmass increased by 1.2% (±1.4%) in the lowHH group, 2.6% (±1.8%) in lowHH+NHnight, and there was a decrease of 0.9% (±4.9%) in CON. VO2max increased by ~4% within both experimental conditions but was not significantly greater than the 1% increase in CON. There was a ~9% difference in pre and post-intervention values in time to exhaustion after lowHH+NH-night (p = 0.03) and a ~8% pre to post-intervention difference (p = 0.006) after lowHH only. We recommend low altitude (1380 m) combined with sleeping in altitude tents (3000 m) as one effective alternative to traditional altitude training methods, which can improve Hbmass. Key pointsIn some countries, it may not be possible to perform classical altitude training effectively, due to the low elevation at altitude training venues. An

  10. Increased Hypoxic Dose After Training at Low Altitude with 9h Per Night at 3000m Normobaric Hypoxia

    PubMed Central

    Carr, Amelia J.; Saunders, Philo U.; Vallance, Brent S.; Garvican-Lewis, Laura A.; Gore, Christopher J.

    2015-01-01

    This study examined effects of low altitude training and a live-high: train-low protocol (combining both natural and simulated modalities) on haemoglobin mass (Hbmass), maximum oxygen consumption (VO2max), time to exhaustion, and submaximal exercise measures. Eighteen elite-level race-walkers were assigned to one of two experimental groups; lowHH (low Hypobaric Hypoxia: continuous exposure to 1380 m for 21 consecutive days; n = 10) or a combined low altitude training and nightly Normobaric Hypoxia (lowHH+NHnight: living and training at 1380 m, plus 9 h.night-1 at a simulated altitude of 3000 m using hypoxic tents; n = 8). A control group (CON; n = 10) lived and trained at 600 m. Measurement of Hbmass, time to exhaustion and VO2max was performed before and after the training intervention. Paired samples t-tests were used to assess absolute and percentage change pre and post-test differences within groups, and differences between groups were assessed using a one-way ANOVA with least significant difference post-hoc testing. Statistical significance was tested at p < 0.05. There was a 3.7% increase in Hbmass in lowHH+NHnight compared with CON (p = 0.02). In comparison to baseline, Hbmass increased by 1.2% (±1.4%) in the lowHH group, 2.6% (±1.8%) in lowHH+NHnight, and there was a decrease of 0.9% (±4.9%) in CON. VO2max increased by ~4% within both experimental conditions but was not significantly greater than the 1% increase in CON. There was a ~9% difference in pre and post-intervention values in time to exhaustion after lowHH+NH-night (p = 0.03) and a ~8% pre to post-intervention difference (p = 0.006) after lowHH only. We recommend low altitude (1380 m) combined with sleeping in altitude tents (3000 m) as one effective alternative to traditional altitude training methods, which can improve Hbmass. Key points In some countries, it may not be possible to perform classical altitude training effectively, due to the low elevation at altitude training venues. An

  11. High-dose vitamin C supplementation increases skeletal muscle vitamin C concentration and SVCT2 transporter expression but does not alter redox status in healthy males.

    PubMed

    Mason, Shaun A; Baptista, Raquel; Della Gatta, Paul A; Yousif, Adel; Russell, Aaron P; Wadley, Glenn D

    2014-12-01

    Antioxidant vitamin C (VC) supplementation is of potential clinical benefit to individuals with skeletal muscle oxidative stress. However, there is a paucity of data reporting on the bioavailability of high-dose oral VC in human skeletal muscle. We aimed to establish the time course of accumulation of VC in skeletal muscle and plasma during high-dose VC supplementation in healthy individuals. Concurrently we investigated the effects of VC supplementation on expression levels of the key skeletal muscle VC transporter sodium-dependent vitamin C transporter 2 (SVCT2) and intramuscular redox and mitochondrial measures. Eight healthy males completed a randomized placebo-controlled, crossover trial involving supplementation with ascorbic acid (2×500 mg/day) over 42 days. Participants underwent muscle and blood sampling on days 0, 1, 7, and 42 during each treatment. VC supplementation significantly increased skeletal muscle VC concentration after 7 days, which was maintained at 42 days (VC 3.0±0.2 (mean±SEM) to 3.9±0.4 mg/100 g wet weight (ww) versus placebo 3.1±0.3 to 2.9±0.2 mg/100 g ww, p=0.001). Plasma VC increased after 1 day, which was maintained at 42 days (VC 61.0±6.1 to 111.5±10.4 µmol/L versus placebo 60.7±5.3 to 59.2±4.8 µmol/L, p<0.001). VC supplementation significantly increased skeletal muscle SVCT2 protein expression (main treatment effect p=0.006) but did not alter skeletal muscle redox measures or citrate synthase activity. A main finding of our study was that 7 days of high-dose VC supplementation was required to significantly increase skeletal muscle vitamin C concentration in healthy males. Our findings implicate regular high-dose vitamin C supplementation as a means to safely increase skeletal muscle vitamin C concentration without impairing intramuscular ascorbic acid transport, antioxidant concentrations, or citrate synthase activity. PMID:25242204

  12. Use of increasing doses of a degradable Deslorelin implant to enhance uterine involution in postpartum lactating dairy cows.

    PubMed

    Silvestre, F T; Risco, C A; Lopez, M; de Sá, M J S; Bilby, T R; Thatcher, W W

    2009-12-01

    Holstein cows received, subcutaneously 1 (1DESL, n=15) or 2 (2DESL, n=12) degradable implant containing 2.1mg of the GnRH agonist Deslorelin or no implant (CON, n=18) within 1.5 days postpartum (dpp). Previous pregnant (PPH) and non-pregnant (PNPH) uterine horns were determined by palpation per rectum. Cows were examined by ultrasonography at 8dpp, 15dpp, 22dpp, 29dpp, and 36dpp (S.E.=1 day) to record ovarian structures, cervical diameter, uterine horns cross-section and lumen diameters, myometrial and endometrial widths. Uterine tone was recorded before ultrasonography. Vaginoscopy was conducted just after ultrasonography for cervical discharge score. At 44dpp cows were inserted with a CIDR followed 7 days later by its removal and injection of PGF(2alpha) 8h later, followed by the Ovsynch 10 days after for timed artificial insemination (TAI). Plasma was analyzed for PGFM daily from parturition to 14dpp and for P(4) trice weekly until 44dpp. Additionally, strategic blood samples were collected during the synchronization protocol to determine whether estrous cyclicity was occurring and ovulation status before and after TAI, respectively. Cows in 1DESL and 2DESL groups had more class 1 follicles (P<0.01), less class 2 (P<0.01) and class 3 follicles (P<0.01) compared with CON. First increase of P(4), indicative of ovulation, occurred in CON (55.5%) cows at 28dpp (S.E.=9 days) and in 1DESL (13.3%) treated cows at 43dpp (S.E.=3). Plasma concentrations of P(4) were suppressed completely in all 2DESL-treated cows before initiation of estrous synchronization. Diameters of PPH (P<0.01), PNPH (P<0.01), uterine horn lumens (P<0.01) were less in the 1DESL and 2DESL groups with greater uterine tone (P=0.07). Frequency distribution of cervical discharge categories did not differ among groups. Proportion of cows with estrous cycles and having ovulations was less (P<0.01) in DESL implant cows compared with CON that was to a greater (P<0.01) extent in the 2DESL. Treatment with

  13. High ethanol dose during early adolescence induces locomotor activation and increases subsequent ethanol intake during late adolescence.

    PubMed

    Acevedo, María Belén; Molina, Juan Carlos; Nizhnikov, Michael E; Spear, Norman E; Pautassi, Ricardo Marcos

    2010-07-01

    Adolescent initiation of ethanol consumption is associated with subsequent heightened probability of ethanol use disorders. The present study examined the relationship between motivational sensitivity to ethanol initiation in adolescent rats and later ethanol intake. Experiment 1 determined that ethanol induces locomotor activation shortly after administration but not if tested at a later post-administration interval. In Experiment 2, adolescent rats were assessed for ethanol-induced locomotor activation on postnatal Day 28. These animals were then evaluated for ethanol-mediated conditioned taste aversion and underwent a 16-day-long ethanol intake protocol. Ethanol-mediated aversive effects were unrelated to ethanol locomotor stimulation or subsequent ethanol consumption patterns. Ethanol intake during late adolescence was greatest in animals initiated to ethanol earliest at postnatal Day 28. Females that were more sensitive to ethanol's locomotor-activating effects showed a transient increase in ethanol self-administration. Blood ethanol concentrations during initiation were not related to ethanol-induced locomotor activation. Adolescent rats appeared sensitive to the locomotor-stimulatory effects of ethanol. Even brief ethanol exposure during adolescence may promote later ethanol intake. PMID:20373327

  14. Castration differentially alters basal and leucine-stimulated tissue protein synthesis in skeletal muscle and adipose tissue.

    PubMed

    Jiao, Qianning; Pruznak, Anne M; Huber, Danuta; Vary, Thomas C; Lang, Charles H

    2009-11-01

    Reduced testosterone as a result of catabolic illness or aging is associated with loss of muscle and increased adiposity. We hypothesized that these changes in body composition occur because of altered rates of protein synthesis under basal and nutrient-stimulated conditions that are tissue specific. The present study investigated such mechanisms in castrated male rats (75% reduction in testosterone) with demonstrated glucose intolerance. Over 9 wk, castration impaired body weight gain, which resulted from a reduced lean body mass and preferential sparing of adipose tissue. Castration decreased gastrocnemius weight, but this atrophy was not associated with reduced basal muscle protein synthesis or differences in plasma IGF-I, insulin, or individual amino acids. However, oral leucine failed to normally stimulate muscle protein synthesis in castrated rats. In addition, castration-induced atrophy was associated with increased 3-methylhistidine excretion and in vitro-determined ubiquitin proteasome activity in skeletal muscle, changes that were associated with decreased atrogin-1 or MuRF1 mRNA expression. Castration decreased heart and kidney weight without reducing protein synthesis and did not alter either cardiac output or glomerular filtration. In contradistinction, the weight of the retroperitoneal fat depot was increased in castrated rats. This increase was associated with an elevated rate of basal protein synthesis, which was unresponsive to leucine stimulation. Castration also decreased whole body fat oxidation. Castration increased TNFα, IL-1α, IL-6, and NOS2 mRNA in fat but not muscle. In summary, the castration-induced muscle wasting results from an increased muscle protein breakdown and the inability of leucine to stimulate protein synthesis, whereas the expansion of the retroperitoneal fat depot appears mediated in part by an increased basal rate of protein synthesis-associated increased inflammatory cytokine expression. PMID:19755668

  15. Transition in Survival From Low-Dose Hyper-Radiosensitivity to Increased Radioresistance Is Independent of Activation of ATM SER1981 Activity

    SciTech Connect

    Krueger, Sarah A.; Collis, Spencer J.; Joiner, Michael C.; Wilson, George D.; Marples, Brian

    2007-11-15

    Purpose: The molecular basis of low-dose hyper-radiosensitivity (HRS) is only partially understood. The aim of this study was to define the roles of ataxia telangiectasia mutated (ATM) activity and the downstream ATM-dependent G{sub 2}-phase cell cycle checkpoint in overcoming HRS and triggering radiation resistance. Methods and Materials: Survival was measured using a high-resolution clonogenic assay. ATM Ser1981 activation was measured by Western blotting. The role of ATM was determined in survival experiments after molecular (siRNA) and chemical (0.4 mM caffeine) inhibition and chemical (20 {mu}g/mL chloroquine, 15 {mu}M genistein) activation 4-6 h before irradiation. Checkpoint responsiveness was assessed in eight cell lines of differing HRS status using flow cytometry to quantify the progression of irradiated (0-2 Gy) G{sub 2}-phase cells entering mitosis, using histone H3 phosphorylation analysis. Results: The dose-response pattern of ATM activation was concordant with the transition from HRS to radioresistance. However, ATM activation did not play a primary role in initiating increased radioresistance. Rather, a relationship was discovered between the function of the downstream ATM-dependent early G{sub 2}-phase checkpoint and the prevalence and overcoming of HRS. Four cell lines that exhibited HRS failed to show low-dose (<0.3-Gy) checkpoint function. In contrast, four HRS-negative cell lines exhibited immediate cell cycle arrest for the entire 0-2-Gy dose range. Conclusion: Overcoming HRS is reliant on the function of the early G{sub 2}-phase checkpoint. These data suggest that clinical exploitation of HRS could be achieved by combining radiotherapy with chemotherapeutic agents that modulate this cell cycle checkpoint.

  16. Low dose of IGF-I increases cell size of skeletal muscle satellite cells via Akt/S6K signaling pathway.

    PubMed

    Gao, Chun-qi; Zhi, Rui; Yang, Zhou; Li, Hai-chang; Yan, Hui-chao; Wang, Xiu-qi

    2015-11-01

    The objective of this study was to investigate the effect of insulin growth factor-I (IGF-I) on the size of pig skeletal muscle satellite cells (SCs). Using microarray, real-time RT-PCR, radioimmunoassay analysis and western blot, we first showed that supplementation of low-dose of IGF-I in culture medium resulted in enlarged cell size of Lantang SCs, only Akt and S6K were up-regulated at both the mRNA and protein levels among almost all of the mTOR pathway key genes, but had no effect on cell number. To elucidate the signaling mechanisms responsible for regulating cell size under low-dose of IGF-I treatment, we blocked Akt and S6K activity with the specific inhibitors MK2206 and PF4708671, respectively. Both inhibitors caused a decrease in cell size. In addition, MK2206 lowered the protein level of p-Akt (Ser473), p-S6K (Thr389), and p-rpS6 (Ser235/236), whereas PF4708671 lowered the protein level of p-S6K (Thr389) and p-rpS6 (Ser235/236). However, low dose of IGF-I didn't affect the protein level of p-mTOR (Ser2448) and p-mTOR (Ser2481). When both inhibitors were applied simultaneously, the effect was the same as that of the Akt inhibition alone. Taken together, we report for the first time that low-dose of IGF-I treatment increases cell size via Akt/S6K signaling pathway. PMID:25923195

  17. Effect of post-exercise protein-leucine feeding on neutrophil function, immunomodulatory plasma metabolites and cortisol during a 6-day block of intense cycling.

    PubMed

    Nelson, Andre R; Jackson, Lara; Clarke, Jim; Stellingwerff, Trent; Broadbent, Suzanne; Rowlands, David S

    2013-09-01

    Whey protein and leucine ingestion following exercise increases muscle protein synthesis and could influence neutrophil function during recovery from prolonged intense exercise. We examined the effects of whey protein and leucine ingestion post-exercise on neutrophil function and immunomodulators during a period of intense cycling. In a randomized double-blind crossover, 12 male cyclists ingested protein/leucine/carbohydrate/fat (LEUPRO 20/7.5/89/22 g h(-1), respectively) or isocaloric carbohydrate/fat control (CON 119/22 g h(-1)) beverages for 1-3 h post-exercise during 6 days of high-intensity training. Blood was taken pre- and post-exercise on days 1, 2, 4 and 6 for phorbol myristate acetate (PMA)-stimulated neutrophil superoxide (O2 (-)) production, immune cell counts, amino acid and lipid metabolism via metabolomics, hormones (cortisol, testosterone) and cytokines (interleukin-6, interleukin-10). During recovery on day 1, LEUPRO ingestion increased mean concentrations of plasma amino acids (glycine, arginine, glutamine, leucine) and myristic acid metabolites (acylcarnitines C14, myristoylcarnitine; and C14:1-OH, hydroxymyristoleylcarnitine) with neutrophil priming capacity, and reduced neutrophil O2 production (15-17 mmol O2 (-) cell(-1) ± 90 % confidence limits 20 mmol O2 (-) cell(-1)). On day 2, LEUPRO increased pre-exercise plasma volume (6.6 ± 3.8 %) but haematological effects were trivial. LEUPRO supplementation did not substantially alter neutrophil elastase, testosterone, or cytokine concentrations. By day 6, however, LEUPRO reduced pre-exercise cortisol 21 % (±15 %) and acylcarnitine C16 (palmitoylcarnitine) during exercise, and increased post-exercise neutrophil O2 (-) (33 ± 20 mmol O2 (-) cell(-1)), relative to control. Altered plasma amino acid and acylcarnitine concentrations with protein-leucine feeding might partly explain the acute post-exercise reduction in neutrophil function and increased exercise-stimulated neutrophil oxidative burst on

  18. One-step biosynthesis of α-ketoisocaproate from L-leucine by an Escherichia coli whole-cell biocatalyst expressing an L-amino acid deaminase from Proteus vulgaris.

    PubMed

    Song, Yang; Li, Jianghua; Shin, Hyun-dong; Du, Guocheng; Liu, Long; Chen, Jian

    2015-01-01

    This work aimed to develop a whole-cell biotransformation process for the production of α-ketoisocaproate from L-leucine. A recombinant Escherichia coli strain was constructed by expressing an L-amino acid deaminase from Proteus vulgaris. To enhance α-ketoisocaproate production, the reaction conditions were optimized as follows: whole-cell biocatalyst 0.8 g/L, leucine concentration 13.1 g/L, temperature 35 °C, pH 7.5, and reaction time 20 h. Under the above conditions, the α-ketoisocaproate titer reached 12.7 g/L with a leucine conversion rate of 97.8%. In addition, different leucine feeding strategies were examined to increase the α-ketoisocaproate titer. When 13.1 g/L leucine was added at 2-h intervals (from 0 to 22 h, 12 addition times), the α-ketoisocaproate titer reached 69.1 g/L, while the leucine conversion rate decreased to 50.3%. We have developed an effective process for the biotechnological production of α-ketoisocaproate that is more environmentally friendly than the traditional petrochemical synthesis approach. PMID:26217895

  19. Human circulating plasma DNA significantly decreases while lymphocyte DNA damage increases under chronic occupational exposure to low-dose gamma-neutron and tritium β-radiation.

    PubMed

    Korzeneva, Inna B; Kostuyk, Svetlana V; Ershova, Liza S; Osipov, Andrian N; Zhuravleva, Veronika F; Pankratova, Galina V; Porokhovnik, Lev N; Veiko, Natalia N

    2015-09-01

    The blood plasma of healthy people contains cell-fee (circulating) DNA (cfDNA). Apoptotic cells are the main source of the cfDNA. The cfDNA concentration increases in case of the organism's cell death rate increase, for example in case of exposure to high-dose ionizing radiation (IR). The objects of the present research are the blood plasma and blood lymphocytes of people, who contacted occupationally with the sources of external gamma/neutron radiation or internal β-radiation of tritium N = 176). As the controls (references), blood samples of people, who had never been occupationally subjected to the IR sources, were used (N = 109). With respect to the plasma samples of each donor there were defined: the cfDNA concentration (the cfDNA index), DNase1 activity (the DNase1 index) and titre of antibodies to DNA (the Ab DNA index). The general DNA damage in the cells was defined (using the Comet assay, the tail moment (TM) index). A chronic effect of the low-dose ionizing radiation on a human being is accompanied by the enhancement of the DNA damage in lymphocytes along with a considerable cfDNA content reduction, while the DNase1 content and concentration of antibodies to DNA (Ab DNA) increase. All the aforementioned changes were also observed in people, who had not worked with the IR sources for more than a year. The ratio cfDNA/(DNase1×Ab DNA × TM) is proposed to be used as a marker of the chronic exposure of a person to the external low-dose IR. It was formulated the assumption that the joint analysis of the cfDNA, DNase1, Ab DNA and TM values may provide the information about the human organism's cell resistivity to chronic exposure to the low-dose IR and about the development of the adaptive response in the organism that is aimed, firstly, at the effective cfDNA elimination from the blood circulation, and, secondly - at survival of the cells, including the cells with the damaged DNA. PMID:26113293

  20. Contrarily to whey and high protein diets, dietary free leucine supplementation cannot reverse the lack of recovery of muscle mass after prolonged immobilization during ageing

    PubMed Central

    Magne, Hugues; Savary-Auzeloux, Isabelle; Migné, Carole; Peyron, Marie-Agnès; Combaret, Lydie; Rémond, Didier; Dardevet, Dominique

    2012-01-01

    During ageing, immobilization periods increase and are partially responsible of sarcopaenia by inducing a muscle atrophy which is hardly recovered from. Immobilization-induced atrophy is due to an increase of muscle apoptotic and proteolytic processes and decreased protein synthesis. Moreover, previous data suggested that the lack of muscle mass recovery might be due to a defect in protein synthesis response during rehabilitation. This study was conducted to explore protein synthesis during reloading and leucine supplementation effect as a nutritional strategy for muscle recovery. Old rats (22–24 months old) were subjected to unilateral hindlimb casting for 8 days (I8) and allowed to recover for 10–40 days (R10–R40). They were fed a casein (±leucine) diet during the recovery. Immobilized gastrocnemius muscles atrophied by 20%, and did not recover even at R40. Amount of polyubiquitinated conjugates and chymotrypsin- and trypsin-like activities of the 26S proteasome increased. These changes paralleled an ‘anabolic resistance’ of the protein synthesis at the postprandial state (decrease of protein synthesis, P-S6 and P-4E-BP1). During the recovery, proteasome activities remained elevated until R10 before complete normalization and protein synthesis was slightly increased. With free leucine supplementation during recovery, if proteasome activities were normalized earlier and protein synthesis was higher during the whole recovery, it nevertheless failed in muscle mass gain. This discrepancy could be due to a ‘desynchronization’ between the leucine signal and the availability of amino acids coming from casein digestion. Thus, when supplemented with leucine-rich proteins (i.e. whey) and high protein diets, animals partially recovered the muscle mass loss. PMID:22351629

  1. Complete genome sequence of Corynebacterium glutamicum CP, a Chinese l-leucine producing strain.

    PubMed

    Gui, Yongli; Ma, Yuechao; Xu, Qingyang; Zhang, Chenglin; Xie, Xixian; Chen, Ning

    2016-02-20

    Here, we report the complete genome sequence of Corynebacterium glutamicum CP, an industrial l-leucine producing strain in China. The whole genome consists of a circular chromosome and a plasmid. The comparative genomics analysis shows that there are many mutations in the key enzyme coding genes relevant to l-leucine biosynthesis compared to C. glutamicum ATCC 13032. PMID:26784991

  2. Differential effects of long-term leucine infusion on tissue protein synthesis in neonatal pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leucine is unique among the amino acids in its ability to promote protein synthesis by activating translation initiation via the mammalian target of rapamycin (mTOR) pathway. Previously, we showed that leucine infusion acutely stimulates protein synthesis in fast-twitch glycolytic muscle of neonatal...

  3. Ultraviolet B radiation increases hairless mouse mast cells in a dose-dependent manner and alters distribution of UV-induced mast cell growth factor.

    PubMed

    Kligman, L H; Murphy, G F

    1996-01-01

    In studies of the effects of chronic UVB irradiation on dermal connective tissue in the hairless mouse, we observed that the number and size of mast cells was increased. Because mast cells are known to be associated with connective tissue remodeling, we examined and quantified the effect of increasing UVB (290-320 nm) doses on this cell. Groups of mice were exposed to filtered FS-40 Westinghouse lamps (290-400 nm: peak irradiance 313 nm) for 1-5 minimal erythema doses (MED) thrice weekly for 10 weeks. Appropriate controls were included. Biopsies, processed for light microscopy, were stained with toluidine blue. Mast cells were counted in 15 high-magnification fields per specimen with upper and lower dermis scored separately. Significant increases in large densely granular mast cells occurred at 2 MED in the lower dermis, in association with a UVB-exacerbated granulomatous reaction. In the upper dermis, mast cells were significantly increased with 3 MED. These findings suggest that mast cells may play a dual role in UV-irradiated skin with those in the lower dermis related to inflammation processes and those in the upper dermis involved in connective tissue modeling. To gain understanding of the mechanism of mast cell recruitment and maturation, we examined the effect of UVB on mast cell growth factor expression. This was enhanced in the epidermis by UVB, with a shift from cytoplasmic staining to membrane-associated or intercellular staining at 2 MED and higher. Dermal dendritic and mononuclear cells also showed increased reactivity. PMID:8577864

  4. Ten Years and Counting: Moving Leucine-Rich Repeat Kinase 2 Inhibitors to the Clinic

    PubMed Central

    West, Andrew B

    2015-01-01

    The burden that Parkinson's disease (PD) exacts on the population continues to increase year after year. Though refinement of symptomatic treatments continues at a reasonable pace, no accepted therapies are available to slow or prevent disease progression. The leucine-rich repeat kinase 2 (LRRK2) gene was identified in PD genetic studies and offers new hope for novel therapeutic approaches. The evidence linking LRRK2 kinase activity to PD susceptibility is presented, as well as seminal discoveries relevant to the prosecution of LRRK2 kinase inhibition. Finally, suggestions are made for predictive preclinical modeling and successful first-in-human trials. © 2014 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society. PMID:25448543

  5. Regulation of Beta-Cell Function and Mass by the Dual Leucine Zipper Kinase.

    PubMed

    Oetjen, Elke

    2016-06-01

    Diabetes mellitus is one of the most rapidly increasing diseases worldwide, whereby approximately 90-95% of patients suffer from type 2 diabetes. Considering its micro- and macrovascular complications like blindness and myocardial infarction, a reliable anti-diabetic treatment is needed. Maintaining the function and the mass of the insulin producing beta-cells despite elevated levels of beta-cell-toxic prediabetic signals represents a desirable mechanism of action of anti-diabetic drugs. The dual leucine zipper kinase (DLK) inhibits the action of two transcription factors within the beta-cell, thereby interfering with insulin secretion and production and the conservation of beta-cell mass. Furthermore, DLK action is regulated by prediabetic signals. Hence, the inhibition of this kinase might protect beta-cells against beta-cell-toxic prediabetic signals and prevent the development of diabetes. DLK might thus present a novel drug target for the treatment of diabetes mellitus type 2. PMID:27100796

  6. Chronic exposure to low doses of lipopolysaccharide and high-fat feeding increases body mass without affecting glucose tolerance in female rats

    PubMed Central

    Dudele, Anete; Fischer, Christina W; Elfving, Betina; Wegener, Gregers; Wang, Tobias; Lund, Sten

    2015-01-01

    Obesity-related inflammation may have a causal role in the development of diabetes and insulin resistance, and studies using animal models of chronic experimental endotoxemia have shown the link. However, many studies use only males, and much less is known about the role of obesity-related inflammation in females. Therefore, we addressed how experimentally induced chronic inflammation affects body mass, energy intake, and glucose metabolism in female rats. Adult female Sprague Dawley rats were instrumented with slow release pellets that delivered a constant daily dose of 53 or 207 μg of lipopolysaccharide (LPS) per rat for 60 days. Control rats were instrumented with vehicle pellets. Due to inflammatory nature of high-fat diet (HFD) half of the rats received HFD (60% of calories from lard), while the other half remained on control diet to detect possible interactions between two modes of induced inflammation. Our results showed that chronic LPS administration increased female rat body mass and calorie intake in a dose-dependent manner, and that HFD further exacerbated these effects. Despite these effects, no effects of LPS and HFD were evident on female rat glucose metabolism. Only LPS elevated expression of inflammatory markers in the hypothalamus. To conclude, female rats respond to experimentally induced chronic inflammation by increasing body mass, but do not develop glucose intolerance in the given period of time. PMID:26537342

  7. Chronic cigarette smoke exposure increases the pulmonary retention and radiation dose of {sup 239}Pu inhaled as {sup 239}PuO{sub 2} by F344 rats

    SciTech Connect

    Finch, G.L.; Lundgren, D.L.; Barr, E.B.; Chen, B.T.; Griffith, W.C.; Hobbs, C.H.; Hoover, M.D.; Nikula, K.J.; Mauderly, J.L.

    1998-12-01

    As a portion of a study to examine how chronic cigarette smoke exposure might alter the risk of lung tumors from inhaled {sup 239}PuO{sub 2} in rats, the effects of smoke exposure on alpha-particle lung dosimetry over the life-span of exposed rats were determined. Male and female rats were exposed to inhaled {sup 239}PuO{sub 2} alone or in combination with cigarette smoke. Animals exposed to filtered air along served as controls for the smoke exposure. Whole-body exposure to mainstream smoke diluted to concentrations of either 100 or 250 mg total particulate matter m{sup {minus}3} began at 6 wk of age and continued for 6 h d{sup {minus}1}, 5 d wk{sup {minus}1}, for 30 mo. A single, pernasal, acute exposure to {sup 239}PuO{sub 2} was given to all rats at 12 wk of age. Exposure to cigarette smoke caused decreased body weight gains in a concentration dependent manner. Lung-to-body weight ratios were increased in smoke-exposed rats. Rats exposed to cigarette smoke before the {sup 239}PuO{sub 2} exposure deposited less {sup 239}Pu in the lung than did controls. Except for male rats exposed to LCS, exposure to smoke retarded the clearance of {sup 239}Pu from the lung compared to control rats through study termination at 870 d after {sup 239}PuO{sub 2} exposure. Radiation doses to lungs were calculated by sex and by exposure group for rats on study for at least 360 d using modeled body weight changes, lung-to-body weight ratios, and standard dosimetric calculations. For both sexes, estimated lifetime radiation doses from the time of {sup 239}PuO{sub 2} exposure to death were 3.8 Gy, 4.4 Gy, or 6.7 Gy for the control, LCS, or HCS exposure groups, respectively. Assuming an approximately linear dose-response relationship between radiation dose and lung neoplasm incidence, approximate increases of 20% or 80% in tumor incidence over controls would be expected in rats exposed to {sup 239}PuO{sub 2} and LCS or {sup 239}PuO{sub 2} and HCS, respectively.

  8. Increased Biological Effective Dose of Radiation Correlates with Prolonged Survival of Patients with Limited-Stage Small Cell Lung Cancer: A Systematic Review

    PubMed Central

    Xu, Xiao; Wang, Bing; Wu, Kan; Deng, Qinghua; Xia, Bing; Ma, Shenglin

    2016-01-01

    Objective Thoracic radiotherapy (TRT) is a critical component of the treatment of limited-stage small cell lung cancer (LS-SCLC). However, the optimal radiation dose/fractionation remains elusive. This study reviewed current evidence and explored the dose-response relationship in patients with LS-SCLC who were treated with radiochemotherapy. Materials and Methods A quantitative analysis was performed through a systematic search of PubMed, Web of Science, and the Cochrane Library. The correlations between the biological effective dose (BED) and median overall survival (mOS), median progression-free survival (mPFS), 1-, 3-, and 5-year overall survival (OS) as well as local relapse (LR) were evaluated. Results In all, 2389 patients in 19 trials were included in this study. Among these 19 trials, seven were conducted in Europe, eight were conducted in Asia and four were conducted in the United States. The 19 trials that were included consisted of 29 arms with 24 concurrent and 5 sequential TRT arms. For all included studies, the results showed that a higher BED prolonged the mOS (R2 = 0.198, p<0.001) and the mPFS (R2 = 0.045, p<0.001). The results also showed that increased BED improved the 1-, 3-, and 5-year OS. A 10-Gy increment added a 6.3%, a 5.1% and a 3.7% benefit for the 1-, 3-, and 5-year OS, respectively. Additionally, BED was negatively correlated with LR (R2 = 0.09, p<0.001). A subgroup analysis of concurrent TRT showed that a high BED prolonged the mOS (p<0.001) and the mPFS (p<0.001), improved the 1-, 3-, and 5-year OS (p<0.001) and decreased the rate of LR (p<0.001). Conclusion This study showed that an increased BED was associated with improved OS, PFS and decreased LR in patients with LS-SCLC who were treated with combined chemoradiotherapy, which indicates that the strategy of radiation dose escalation over a limited time frame is worth exploring in a prospective clinical trial. PMID:27227819

  9. Inosine Triphosphatase Genetic Variants are Protective Against Anemia During Antiviral Therapy for HCV2/3 But Do Not Decrease Dose Reductions of RBV Or Increase SVR

    PubMed Central

    Thompson, Alexander J.; Santoro, Rosanna; Piazzolla, Valeria; Clark, Paul J.; Naggie, Susanna; Tillmann, Hans L.; Patel, Keyur; Muir, Andrew J.; Shianna, Kevin V.; Mottola, Leonardo; Petruzzellis, Daniela; Romano, Mario; Sogari, Fernando; Facciorusso, Domenico; Goldstein, David B.; McHutchison, John G.; Mangia, Alessandra

    2016-01-01

    Two functional variants in the inosine triphosphatase (ITPA) gene causing inosine triphos-phatase (ITPase) deficiency protect against ribavirin (RBV)-induced hemolytic anemia and the need for RBV dose reduction in patients with genotype 1 hepatitis C virus (HCV). No data are available for genotype 2/3 HCV. We evaluated the association between the casual ITPA variants and on-treatment anemia in a well-characterized cohort of genotype 2/3 patients treated with variable-duration pegylated interferon alfa-2b (PEG-IFN-α2b) and RBV. Two hundred thirty-eight Caucasian patients were included in this retrospective study [185 (78%) with genotype 2 and 53 (22%) with genotype 3]. Patients were treated with PEG-IFN-α2b plus weight-based RBV (1000/1200 mg) for 12 (n = 109) or 24 weeks (n = 129). The ITPA polymorphisms rs1127354 and rs7270101 were genotyped, and an ITPase deficiency variable was defined that combined both ITPA variants according to their effect on ITPase activity. The primary endpoint was hemoglobin (Hb) reduction in week 4. We also considered Hb reduction over the course of therapy, the need for RBV dose modification, and the rate of sustained virological response (SVR). The ITPA variants were strongly and independently associated with protection from week 4 anemia (P = 10−6 for rs1127354 and P = 10−7 for rs7270101). Combining the variants into the ITPase deficiency variable increased the strength of association (P = 10−11). ITPase deficiency protected against anemia throughout treatment. ITPase deficiency was associated with a delayed time to an Hb level < 10 g/dL (hazard ratio = 0.25, 95% confidence interval = 0.08–0.84, P = 0.025) but not with the rate of RBV dose modification (required per protocol at Hb < 9.5 g/dL). There was no association between the ITPA variants and SVR. Conclusion Two ITPA variants were strongly associated with protection against treatment-related anemia in patients with genotype 2/3 HCV, but they did not decrease the need

  10. Increase of EPA-derived hydroxy, epoxy and dihydroxy fatty acid levels in human plasma after a single dose of long-chain omega-3 PUFA

    PubMed Central

    Schuchardt, Jan Philipp; Schneider, Inga; Willenberg, Ina; Yang, Jun; Hammock, Bruce D.; Hahn, Andreas; Schebb, Nils Helge

    2014-01-01

    Introduction Several supplementation studies with long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) describe an increase of EPA-derived hydroxy, epoxy and dihydroxy fatty acids in blood, while changes in levels of other LC n-3 and n-6 PUFA-derived oxylipins were minor. In order to investigate the kinetics of changes in oxylipin levels in response to LC n-3 PUFA ingestion, we conducted a single dose treatment study with healthy subjects. Subjects and methods In the present kinetic study, we compared patterns of hydroxy, epoxy and dihydroxy fatty acids in plasma of 6 healthy men before and after 6, 8, 24, and 48 h of fish oil (1008 mg EPA and 672 mg DHA) ingestion. Levels of EPA- as well as other LC PUFA-derived hydroxy, epoxy and dihydroxy fatty acids were analyzed in plasma by LC–MS. Additionally, levels of these oxylipins were compared with their parent PUFA levels in plasma phospholipids. Results All EPA-derived oxylipin levels were significantly increased 6 h after LC n-3 PUFA ingestion and gradually drop thereafter reaching the baseline levels about 48 h after treatment. The relative increase in EPA plasma phospholipid levels highly correlated with the increase of plasma EPA-derived oxylipin levels at different time points. In contrast, plasma levels of arachidonic acid- and DHA-derived oxylipins as well as parent PUFA levels in plasma phospholipids were hardly changed. Discussion and conclusions Our findings demonstrate that a single dose of LC n-3 PUFAs can rapidly induce a shift in the EPA oxylipin profile of healthy subjects within a few hours. Taking the high biological activity of the EPA-derived epoxy fatty acids into account, even short-term treatment with LC n-3 PUFAs may cause systemic effects, which warrant further investigation. PMID:24667634

  11. Chiral conducting surfaces via electrochemical oxidation of L-leucine-oligothiophenes.

    PubMed

    McTiernan, Christopher D; Omri, Karim; Chahma, M'hamed

    2010-09-17

    Polythiophenes bearing a specific chiral center such as L-leucine have been prepared via the electrochemical oxidation of a series of L-leucine functionalized oligothiophenes (monothiophenes and terthiophenes). These oligothiophenes have been prepared through the condensation of L-leucine methyl ester and the corresponding thiophene monomers in the presence of hydroxybenzotriazole (HOBt) and N,N'-dicyclohexylcarbodiimide (DCC) followed by hydrolysis of the esters. The electroactive polymers are electrochemically stable and exhibit excellent adhesive properties on electrode surfaces (platinum, gold, and glassy carbon) as well as interesting optical properties in both doped and undoped states. Hydrogen bonds between a free amino acid (L-leucine, D-leucine, L-alanine, D-alanine, and D/L-alanine) and the L-leucine based polythiophenes (chiral conducting surface) were probed using cyclic voltammetry. Preliminary results show that the capacitive current of a modified L-leucine-polythiophene electrode decreases as a result of the formation of a hydrogen bond barrier on the surface of the chiral conducting surface accompanied with a shift of the oxidation potential. Cyclic voltammetry responses resulting from the interaction of the chiral conducting surface with L and Dfree amino acid isomers are similar. The formation of hydrogen bonds between the chiral conducting surfaces and the free amino acids was characterized by (1)H NMR. A chemical shift was observed for the N-H group in monomer 6 as a result of the hydrogen bond formation between the L-leucine methyl ester (D-leucine methyl ester, D/L-leucine methyl ester) and monomer 6. PMID:20718451

  12. Sodium orthovanadate associated with pharmacological doses of ascorbate causes an increased generation of ROS in tumor cells that inhibits proliferation and triggers apoptosis.

    PubMed

    Günther, Tânia Mara Fischer; Kviecinski, Maicon Roberto; Baron, Carla Cristine; Felipe, Karina Bettega; Farias, Mirelle Sifroni; da Silva, Fabiana Ourique; Bücker, Nádia Cristina Falcão; Pich, Claus Tröger; Ferreira, Eduardo Antonio; Wilhelm Filho, Danilo; Verrax, Julien; Calderon, Pedro Buc; Pedrosa, Rozangela Curi

    2013-01-18

    Pharmacological doses of ascorbate were evaluated for its ability to potentiate the toxicity of sodium orthovanadate (Na(3)VO(4)) in tumor cells. Cytotoxicity, inhibition of cell proliferation, generation of ROS and DNA fragmentation were assessed in T24 cells. Na(3)VO(4) was cytotoxic against T24 cells (EC(50)=5.8 μM at 24 h), but in the presence of ascorbate (100 μM) the EC(50) fell to 3.3 μM. Na(3)VO(4) plus ascorbate caused a strong inhibition of cell proliferation (up to 20%) and increased the generation of ROS (4-fold). Na(3)VO(4) did not directly cleave plasmid DNA, at this aspect no synergism was found occurring between Na(3)VO(4) and ascorbate once the resulting action of the combination was no greater than that of both substances administered separately. Cells from Ehrlich ascites carcinoma-bearing mice were used to determine the activity of antioxidant enzymes, the extent of the oxidative damage and the type of cell death. Na(3)VO(4) alone, or combined with ascorbate, increased catalase activity, but only Na(3)VO(4) plus ascorbate increased superoxide dismutase activity (up to 4-fold). Oxidative damage on proteins and lipids was higher due to the treatment done with Na(3)VO(4) plus ascorbate (2-3-fold). Ascorbate potentiated apoptosis in tumor cells from mice treated with Na(3)VO(4). The results indicate that pharmacological doses of ascorbate enhance the generation of ROS induced by Na(3)VO(4) in tumor cells causing inhibition of proliferation and apoptosis. Apoptosis induced by orthovanadate and ascorbate is closer related to inhibition on Bcl-xL and activation of Bax. Our data apparently rule out a mechanism of cell demise p53-dependent or related to Cdk2 impairment. PMID:23261463

  13. Prenatal Exposure to Low Doses of Bisphenol A Increases Pituitary Proliferation and Gonadotroph Number in Female Mice Offspring at Birth1

    PubMed Central

    Brannick, Katherine E.; Craig, Zelieann R.; Himes, Ashley D.; Peretz, Jackye R.; Wang, Wei; Flaws, Jodi A.; Raetzman, Lori T.

    2012-01-01

    ABSTRACT The pituitary gland is composed of hormone-producing cells essential for homeostasis and reproduction. Pituitary cells are sensitive to endocrine feedback in the adult and can have altered hormonal secretion from exposure to the endocrine disruptor bisphenol A (BPA). BPA is a prevalent plasticizer used in food and beverage containers, leading to widespread human exposure. Although prenatal exposure to BPA can impact reproductive function in the adult, the effects of BPA on the developing pituitary are unknown. We hypothesized that prenatal exposure to low doses of BPA impacts gonadotroph cell number or parameters of hormone synthesis. To test this, pregnant mice were administered 0.5 μg/kg/day of BPA, 50 μg/kg/day of BPA, or vehicle beginning on Embryonic Day 10.5. At parturition, pituitaries from female offspring exposed in utero to either dose of BPA had increased proliferation, as assessed by mKi67 mRNA levels and immunohistochemistry. Coincidently, gonadotroph number also increased in treated females. However, we observed a dichotomy between mRNA levels of Lhb and Fshb. Female mice exposed to 0.5 μg/kg/day BPA had increased mRNA levels of gonadotropins and the gonadotropin-receptor hormone (GNRH) receptor (Gnrhr), which mediates GNRH regulation of gonadotropin production and release. In contrast, mice treated with 50 μg/kg/day of BPA had decreased gonadotropin mRNA levels, Gnrhr and Nr5a1, a transcription factor required for gonadotroph differentiation. No other pituitary hormones were altered on the day of birth in response to in utero BPA exposure, and male pituitaries showed no change in the parameters tested. Collectively, these results show that prenatal exposure to BPA affects pituitary gonadotroph development in females. PMID:22875908

  14. Prebiotic fibres dose-dependently increase satiety hormones and alter Bacteroidetes and Firmicutes in lean and obese JCR:LA-cp rats.

    PubMed

    Parnell, Jill A; Reimer, Raylene A

    2012-02-01

    There is a growing interest in modulating gut microbiota with diet in the context of obesity. The purpose of the present study was to evaluate the dose-dependent effects of prebiotics (inulin and oligofructose) on gut satiety hormones, energy expenditure, gastric emptying and gut microbiota. Male lean and obese JCR:LA-cp rats were randomised to either of the following: lean 0 % fibre (LC), lean 10 % fibre (LF), lean 20 % fibre (LHF), obese 0 % fibre (OC), obese 10 % fibre (OF) or obese 20 % fibre (OHF). Body composition, gastric emptying, energy expenditure, plasma satiety hormone concentrations and gut microbiota (using quantitative PCR) were measured. Caecal proglucagon and peptide YY mRNA levels were up-regulated 2-fold in the LF, OF and OHF groups and 3-fold in the LHF group. Ghrelin O-acyltransferase mRNA levels were higher in obese v. lean rats and decreased in the OHF group. Plasma ghrelin response was attenuated in the LHF group. Microbial species measured in the Bacteroidetes division decreased, whereas those in the Firmicutes increased in obese v. lean rats and improved with prebiotic intake. Bifidobacterium and Lactobacillus increased in the OHF v. OC group. Bacteroides and total bacteria negatively correlated with percentage of body fat and body weight. Enterobacteriaceae increased in conjunction with glucose area under the curve (AUC) and glucagon-like peptide-1 AUC. Bacteroides and total bacteria correlated positively with ghrelin AUC yet negatively with insulin AUC and energy intake (P < 0·05). Several of the mechanisms through which prebiotics act (food intake, satiety hormones and alterations in gut microbiota) are regulated in a dose-dependent manner. The combined effects of prebiotics may have therapeutic potential for obesity. PMID:21767445

  15. Vaccination of cattle with a high dose of BCG vaccine 3 weeks after experimental infection with Mycobacterium bovis increased the inflammatory response, but not tuberculous pathology.

    PubMed

    Buddle, Bryce M; Shu, Dairu; Parlane, Natalie A; Subharat, Supatsak; Heiser, Axel; Hewinson, R Glyn; Vordermeier, H Martin; Wedlock, D Neil

    2016-07-01

    A study was undertaken to determine whether BCG vaccination of cattle post-challenge could have an effect on a very early Mycobacterium bovis infection. Three groups of calves (n = 12/group) were challenged endobronchially with M. bovis and slaughtered 13 weeks later to examine for tuberculous lesions. One group had been vaccinated prophylactically with BCG Danish vaccine 21 weeks prior to challenge; a second group was vaccinated with a 4-fold higher dose of BCG Danish 3 weeks post-challenge and the third group, remained non-vaccinated. Vaccination prior to challenge induced only minimal protection with just a significant reduction in the lymph node lesion scores. Compared to the non-vaccinated group, BCG vaccination post-challenge produced no reduction in gross pathology and histopathology, but did result in significant increases in mRNA expression of pro-inflammatory mediators (IFN-γ, IL-12p40, IL-17A, IRF-5, CXCL9, CXCL10, iNOs, and TNF-α) in the pulmonary lymph nodes. Although there was no significant differences in the gross pathology and histopathology between the post-challenge BCG and non-vaccinated groups, the enhanced pro-inflammatory immune responses observed in the post-challenge BCG group suggest caution in the use of high doses of BCG where there is a possibility that cattle may be infected with M. bovis prior to vaccination. PMID:27450013

  16. γ-Tocopherol abolishes postprandial increases in plasma methylglyoxal following an oral dose of glucose in healthy, college-aged men.

    PubMed

    Masterjohn, Christopher; Mah, Eunice; Guo, Yi; Koo, Sung I; Bruno, Richard S

    2012-03-01

    Postprandial hyperglycemia contributes to the risk of cardiovascular disease in part by increasing concentrations of the reactive dicarbonyl methylglyoxal (MGO), a byproduct of glucose metabolism. Oxidative stress increases MGO formation from glucose in vitro and decreases its glutathione-dependent detoxification to lactate. We hypothesized that the antioxidant γ-tocopherol, a form of vitamin E, would decrease hyperglycemia-mediated postprandial increases in plasma MGO in healthy, normoglycemic, college-aged men. Participants (n=12 men; 22.3±1.0 years; 29.3±2.4 kg/m(2)) received an oral dose of glucose (75 g) in the fasted state prior to and following 5-day ingestion of a vitamin E supplement enriched in γ-tocopherol (500 mg/day). γ-Tocopherol supplementation increased (P<.0001) plasma γ-tocopherol from 2.22±0.32 to 7.06±0.71 μmol/l. Baseline MGO concentrations and postprandial hyperglycemic responses were unaffected by γ-tocopherol supplementation (P>.05). Postprandial MGO concentrations increased in the absence of supplemental γ-tocopherol (P<.05), but not following γ-tocopherol supplementation (P>.05). Area under the curve for plasma MGO was significantly (P<.05) smaller with the supplementation of γ-tocopherol than without (area under the curve (0-180 min), -778±1010 vs. 2277±705). Plasma concentrations of γ-carboxyethyl-hydroxychroman, reduced glutathione and markers of total antioxidant capacity increased after supplementation, and these markers and plasma γ-tocopherol were inversely correlated with plasma MGO (r=-0.48 to -0.67, P<.05). These data suggest that short-term supplementation of γ-tocopherol abolishes the oral glucose-mediated increases in postprandial MGO through its direct and indirect antioxidant properties and may reduce hyperglycemia-mediated cardiovascular disease risk. PMID:21543210

  17. High-dose dibutyl phthalate improves performance of F1 generation male rats in spatial learning and increases hippocampal BDNF expression independent on p-CREB immunocontent.

    PubMed

    Li, Yuanfeng; Li, Tao; Zhuang, Meizhu; Wang, Kailiang; Zhang, Juan; Shi, Nian

    2010-01-01

    Dibutyl phthalate (DBP), an important representative of endocrine disrupting chemical, is suspected of affecting the cognitive function of humans and animals. In this study, effects of DBP on maze performance in male rats were evaluated by spatial learning tasks; the effects of DBP on the expression of brain-derived neurotrophic factor (BDNF) were also analyzed in both mRNA and mature protein levels in the hippocampus, with intent to investigate the possible mechanism underlying the behavioral findings. Pregnant Wistar rats were treated orally by gavage with 0, 25, 75, 225 and 675mgDBP/kgBW/day from gestational day (GD) 6 to postnatal day (PND) 21, and then the weaned offspring continued receiving the same treatment till PND 28. We found that male pups treated with high-dose DBP showed enhancement in spatial acquisition in a Morris water maze during PNDs 30-33, and displayed better retention of spatial memory in a probe trial after a reverse trail during PNDs 60-62. Real-time PCR and western blotting analysis of the hippocampus from DBP-treated male rats on PND 21 revealed an increase in BDNF expression, compared to the vehicle-matched control. BDNF variant III, a transcription promoted by active CREB (i.e. p-CREB), as well as the immunocontent of p-CREB, was scarcely altered by the treatment. Our results suggest that developmental treatment with high-dose DBP improves spatial memory in male rats, and this effect may be related to an increase in BDNF expression in the hippocampus in a p-CREB independent route. PMID:21787579

  18. Adrenal Insufficiency in Australia: Is it Possible that the Use of Lower Dose, Short-Acting Glucocorticoids has Increased the Risk of Adrenal Crises?

    PubMed

    Rushworth, R L; Torpy, D J

    2015-06-01

    Morbidity from adrenal insufficiency (AI) in Australia is poorly described. The objective of this study was to evaluate AI morbidity patterns in adults between 1999/2000 and 2011/2012 using national databases. A descriptive study of hospitalisations for AI and adrenal crises (AC) in adults and trends in prescriptions for 2 short-acting glucocorticoids (GC) was designed. The setting was the Australian healthcare system. Main outcome measures are the trends in hospitalisation and prescription rates. There were 7,378 hospital admissions for treatment of AI in adults between 1999/00 and 2011/12. Of these, 29.5% were for an AC. Admission rates for AC increased from 9.5 to 12.4 admissions/10(6)/year (p < 0.05). There was a 5.8% decrease in admission rates for AI (excluding AC), from 27.0 to 25.5/10(6)/year (p = ns). Short-acting GC [hydrocortisone (HCT) and cortisone acetate (CA)] prescription rates increased significantly (p < 0.001) from 3,176.1/10(6) to 3,463.8/10(6). Prescription rates for CA decreased by 22.4% (p < 0.001) but HCT prescription rates increased to 77.1% (p < 0.001). The increase in AC admission rates was positively correlated with the rise in both the total GC prescription rate (r = 0.63, p < 0.05) and the HCT prescription rate (r = 0.74, p< 0.01). Over the 13-year study period, there was a 30.8% increase in hospitalisation rates for ACs and a concomitant 77.1% increase in prescribing of HCT. The association between AC events and HCT use and/or reduced effective GC dose is plausibly causal, but confirmatory studies are required before suggesting any change to GC replacement in AI. PMID:25738995

  19. Design and characterization of short antimicrobial peptides using leucine zipper templates with selectivity towards microorganisms.

    PubMed

    Ahmad, Aqeel; Azmi, Sarfuddin; Srivastava, Saurabh; Kumar, Amit; Tripathi, Jitendra Kumar; Mishra, Nripendra N; Shukla, Praveen K; Ghosh, Jimut Kanti

    2014-11-01

    Design of antimicrobial peptides with selective activity towards microorganisms is an important step towards the development of new antimicrobial agents. Leucine zipper sequence has been implicated in cytotoxic activity of naturally occurring antimicrobial peptides; moreover, this motif has been utilized for the design of novel antimicrobial peptides with modulated cytotoxicity. To understand further the impact of substitution of amino acids at 'a' and/or 'd' position of a leucine zipper sequence of an antimicrobial peptides on its antimicrobial and cytotoxic properties four short peptides (14-residue) were designed on the basis of a leucine zipper sequence without or with replacement of leucine residues in its 'a' and 'd' positions with D-leucine or alanine or proline residue. The original short leucine zipper peptide (SLZP) and its D-leucine substituted analog, DLSA showed comparable activity against the tested Gram-positive and negative bacteria and the fungal strains. The alanine substituted analog (ASA) though showed appreciable activity against the tested bacteria, it showed to some extent lower activity against the tested fungi. However, the proline substituted analog (PSA) showed lower activity against the tested bacterial or fungal strains. Interestingly, DLSA, ASA and PSA showed significantly lower cytotoxicity than SLZP against both human red blood cells (hRBCs) and murine 3T3 cells. Cytotoxic and bactericidal properties of these peptides matched with peptide-induced damage/permeabilization of mammalian cells and bacteria or their mimetic lipid vesicles suggesting cell membrane could be the target of these peptides. As evidenced by tryptophan fluorescence and acrylamide quenching studies the peptides showed similarities either in interaction or in their localization within the bacterial membrane mimetic negatively charged lipid vesicles. Only SLZP showed localization inside the mammalian membrane mimetic zwitterionic lipid vesicles. The results show

  20. Axon reaction in hypoglossal and dorsal motor vagal neurons of adult rat: incorporation of (3H)leucine

    SciTech Connect

    Aldskogius, H.; Barron, K.D.; Regal, R.

    1984-07-01

    Pairs of adult rats received (/sup 3/H)leucine 0.25, 1, and 16 h before killing and zero to 164 days after unilateral cervical vagotomy and hypoglossal neurotomy. Grain counts and morphometric measurements were made on axotomized and uninjured neurons in histoautoradiographs of the medullary nuclei. Axotomized hypoglossal neurons, which largely survive the injury, both enlarged and incorporated increased amounts of tritiated leucine at each labeling interval, 3 through 28 days postoperatively. In the vagal dorsal motor nucleus (DMN), axotomized cells, which frequently die after neurotomy, enlarged slightly through 28 days postoperatively, then atrophied; DMN neurons increased amino acid uptake for a shorter period (days 7 through 14) than hypoglossal neurons. Axotomized DMN neurons did not sustain increased protein synthesis as long as their hypoglossal counterparts and seemed to fail to increase synthesis of structural proteins with long half-lives (16-h labeling interval). The frequently necrobiotic response of axotomized DMN neurons may relate to these phenomena. From these and earlier results, the authors conclude that axon reaction appears to differ fundamentally in peripheral and central neurons. This difference may have significance for research on regeneration in the central nervous system.

  1. Escherichia coli Lrp (Leucine-Responsive Regulatory Protein) Does Not Directly Regulate Expression of the leu Operon Promoter

    PubMed Central

    Landgraf, Jeffrey R.; Boxer, Jonathan A.; Calvo, Joseph M.

    1999-01-01

    Studies by R. Lin et al. (J. Bacteriol. 174:1948–1955, 1992) suggested that the Escherichia coli leu operon might be a member of the Lrp regulon. Their results were obtained with a leucine auxotroph; in leucine prototrophs grown in a medium lacking leucine, there was little difference in leu operon expression between lrp+ and lrp strains. Furthermore, when leuP-lacZ transcriptional fusions that lacked the leu attenuator were used, expression from the leu promoter varied less than twofold between lrp+ and lrp strains, irrespective of whether or not excess leucine was added to the medium. The simplest explanation of the observations of Lin et al. is that the known elevated leucine transport capacity of lrp strains (S. A. Haney et al., J. Bacteriol. 174:108–115, 1992) leads to very high intracellular levels of leucine for strains grown with leucine, resulting in the superattenuation of leu operon expression. PMID:10515950

  2. Sodium orthovanadate associated with pharmacological doses of ascorbate causes an increased generation of ROS in tumor cells that inhibits proliferation and triggers apoptosis

    SciTech Connect

    Günther, T-hat nia Mara Fischer; Kviecinski, Maicon Roberto; Baron, Carla Cristine; Felipe, Karina Bettega; Farias, Mirelle Sifroni; Ourique da Silva, Fabiana; Bücker, Nádia Cristina Falcão; Pich, Claus Tröger; Ferreira, Eduardo Antonio; Filho, Danilo Wilhelm; Verrax, Julien; Calderon, Pedro Buc; Pedrosa, Rozangela Curi

    2013-01-18

    Graphical abstract: -- Abstract: Pharmacological doses of ascorbate were evaluated for its ability to potentiate the toxicity of sodium orthovanadate (Na{sub 3}VO{sub 4}) in tumor cells. Cytotoxicity, inhibition of cell proliferation, generation of ROS and DNA fragmentation were assessed in T24 cells. Na{sub 3}VO{sub 4} was cytotoxic against T24 cells (EC{sub 50} = 5.8 μM at 24 h), but in the presence of ascorbate (100 μM) the EC{sub 50} fell to 3.3 μM. Na{sub 3}VO{sub 4} plus ascorbate caused a strong inhibition of cell proliferation (up to 20%) and increased the generation of ROS (4-fold). Na{sub 3}VO{sub 4} did not directly cleave plasmid DNA, at this aspect no synergism was found occurring between Na{sub 3}VO{sub 4} and ascorbate once the resulting action of the combination was no greater than that of both substances administered separately. Cells from Ehrlich ascites carcinoma-bearing mice were used to determine the activity of antioxidant enzymes, the extent of the oxidative damage and the type of cell death. Na{sub 3}VO{sub 4} alone, or combined with ascorbate, increased catalase activity, but only Na{sub 3}VO{sub 4} plus ascorbate increased superoxide dismutase activity (up to 4-fold). Oxidative damage on proteins and lipids was higher due to the treatment done with Na{sub 3}VO{sub 4} plus ascorbate (2–3-fold). Ascorbate potentiated apoptosis in tumor cells from mice treated with Na{sub 3}VO{sub 4}. The results indicate that pharmacological doses of ascorbate enhance the generation of ROS induced by Na{sub 3}VO{sub 4} in tumor cells causing inhibition of proliferation and apoptosis. Apoptosis induced by orthovanadate and ascorbate is closer related to inhibition on Bcl-xL and activation of Bax. Our data apparently rule out a mechanism of cell demise p53-dependent or related to Cdk2 impairment.

  3. Prophylactic activity of increasing doses of intravenous histamine in refractory migraine: Retrospective observations of a series of patients with migraine without aura

    PubMed Central

    Pietrini, Umberto; De Luca, Massimo; Del Bene, Enrico; De Cesaris, Francesco; Bertinotti, Luca; Colangelo, Nicola; Moggi Pignone, Alberto

    2004-01-01

    Background: Histamine is thought to play a pivotal role in the modulation of peripheral and central pain. The administration of increasing doses of histamine may lead to desensitization of receptors of histamine types 1 and 2, causing meningeal vasodilation, and to depletion of neuropeptides in the trigeminal ganglion, thus inhibiting the initiation of migraine. Objective: In this study, the efficacy and tolerability of increasing doses of IV histamine in migraine prophylaxis were investigated. Methods: This single-center, open-label, retrospective, controlled study was conducted at the Headache Center (Department of Internal Medicine, University of Florence, Villa Monna Tessa, Italy). Patients included in the study had 3 to 6 migraines without aura per month that were refractory to common symptomatic and prophylactic agents in the 6 months preceding the study. Patients were treated with IV histamine hydrochloride for 21 days starting with a dosage of 0.5 mg/d and increasing to 4.0 mg/d. To assess the efficacy of the treatment, these patients were matched for age; sex; and frequency, duration, and severity of attacks with untreated migraineurs. Clinical benefit was defined as ⩽ 1 migraine of mild intensity per month. Tolerability was assessed during the hospitalization period, and patients were instructed to contact the Headache Center to report any adverse effects after hospital discharge. Results: The histamine group comprised 47 patients (40 women, 7 men; mean [SD] age, 42.0 [8.6] years) and the control group comprised 23 patients (20 women, 3 men; mean [SD] age, 38.8 [8.4] years). The histamine-treated patients showed a clinical benefit lasting for a mean of 10.4 (4.2) months, while the patients in the control group showed a clinical benefit of 3.8 (1.9) months. The difference in the duration of the clinical benefit between the 2 groups was 6.6 months (95% CI, 5.15-7.99). Adverse effects consisted of flushing, heat sensation during infusion, headache, and

  4. Trophic restructuring (Wieser 1953) of free-living nematode in marine sediment experimentally enriched to increasing doses of pharmaceutical penicillin G.

    PubMed

    Nasri, Ahmed; Jouili, Soufiane; Boufahja, Fehmi; Hedfi, Amor; Saidi, Ibtihel; Mahmoudi, Ezzeddine; Aïssa, Patricia; Essid, Naceur; Hamouda, Beyrem

    2016-08-01

    Trophic structure of free living nematode from Bizerte lagoon was tested by a microcosmic study after 30 days of exposure with 5 increasing doses of pharmaceutical penicillin G (D1: 3 mg L(-1), D2: 30 mg L(-1), D3: 300 mg L(-1), D4: 600 mg L(-1), D5: 700 mg L(-1)). Results showed significant differences between nematode assemblages from undisturbed controls and those from penicillin G treatments. Selective deposit-feeders (1A) or nonselective deposit-feeders (1B), very abundant in the control microcosm, were significantly affected and their dominance declined significantly. Epistrate feeders (2A) were significantly gradual increase for all microcosms treated with penicillin G, appeared to be more tolerant to the antibiotic and to take advantage of the growing scarcity of other trophic groups. Compared to the control microcosms, omnivorous-carnivorous (2B) was found to be higher in all treated microcosms, with the exception of those treated with D5. Trophic index (Σθ(2)) was significantly reduced in all microcosms treated whereas trophic ratio 1B/2A appears to be insignificant. PMID:27230096

  5. Increased phytotoxic O3 dose accelerates autumn senescence in an O3-sensitive beech forest even under the present-level O3.

    PubMed

    Kitao, Mitsutoshi; Yasuda, Yukio; Kominami, Yuji; Yamanoi, Katsumi; Komatsu, Masabumi; Miyama, Takafumi; Mizoguchi, Yasuko; Kitaoka, Satoshi; Yazaki, Kenichi; Tobita, Hiroyuki; Yoshimura, Kenichi; Koike, Takayoshi; Izuta, Takeshi

    2016-01-01

    Ground-level ozone (O3) concentrations are expected to increase over the 21(st) century, especially in East Asia. However, the impact of O3 has not been directly assessed at the forest level in this region. We performed O3 flux-based risk assessments of carbon sequestration capacity in an old cool temperate deciduous forest, consisting of O3-sensitive Japanese beech (Fagus crenata), and in a warm temperate deciduous and evergreen forest dominated by O3-tolerant Konara oak (Quercus serrata) based on long-term CO2 flux observations. On the basis of a practical approach for a continuous estimation of canopy-level stomatal conductance (Gs), higher phytotoxic ozone dose above a threshold of 0 uptake (POD0) with higher Gs was observed in the beech forest than that in the oak forest. Light-saturated gross primary production, as a measure of carbon sequestration capacity of forest ecosystem, declined earlier in the late growth season with increasing POD0, suggesting an earlier autumn senescence, especially in the O3-sensitive beech forest, but not in the O3-tolerant oak forest. PMID:27601188

  6. Increased phytotoxic O3 dose accelerates autumn senescence in an O3-sensitive beech forest even under the present-level O3

    PubMed Central

    Kitao, Mitsutoshi; Yasuda, Yukio; Kominami, Yuji; Yamanoi, Katsumi; Komatsu, Masabumi; Miyama, Takafumi; Mizoguchi, Yasuko; Kitaoka, Satoshi; Yazaki, Kenichi; Tobita, Hiroyuki; Yoshimura, Kenichi; Koike, Takayoshi; Izuta, Takeshi

    2016-01-01

    Ground-level ozone (O3) concentrations are expected to increase over the 21st century, especially in East Asia. However, the impact of O3 has not been directly assessed at the forest level in this region. We performed O3 flux-based risk assessments of carbon sequestration capacity in an old cool temperate deciduous forest, consisting of O3-sensitive Japanese beech (Fagus crenata), and in a warm temperate deciduous and evergreen forest dominated by O3-tolerant Konara oak (Quercus serrata) based on long-term CO2 flux observations. On the basis of a practical approach for a continuous estimation of canopy-level stomatal conductance (Gs), higher phytotoxic ozone dose above a threshold of 0 uptake (POD0) with higher Gs was observed in the beech forest than that in the oak forest. Light-saturated gross primary production, as a measure of carbon sequestration capacity of forest ecosystem, declined earlier in the late growth season with increasing POD0, suggesting an earlier autumn senescence, especially in the O3-sensitive beech forest, but not in the O3-tolerant oak forest. PMID:27601188

  7. Glucocorticoid Induced Leucine Zipper inhibits apoptosis of cardiomyocytes by doxorubicin

    SciTech Connect

    Aguilar, David; Strom, Joshua; Chen, Qin M.

    2014-04-01

    Doxorubicin (Dox) is an indispensable chemotherapeutic agent for the treatment of various forms of neoplasia such as lung, breast, ovarian, and bladder cancers. Cardiotoxicity is a major concern for patients receiving Dox therapy. Previous work from our laboratory indicated that glucocorticoids (GCs) alleviate Dox-induced apoptosis in cardiomyocytes. Here we have found Glucocorticoid-Induced Leucine Zipper (GILZ) to be a mediator of GC-induced cytoprotection. GILZ was found to be induced in cardiomyocytes by GC treatment. Knocking down of GILZ using siRNA resulted in cancelation of GC-induced cytoprotection against apoptosis by Dox treatment. Overexpressing GILZ by transfection was able to protect cells from apoptosis induced by Dox as measured by caspase activation, Annexin V binding and morphologic changes. Western blot analyses indicate that GILZ overexpression prevented cytochrome c release from mitochondria and cleavage of caspase-3. When bcl-2 family proteins were examined, we found that GILZ overexpression causes induction of the pro-survival protein Bcl-xL. Since siRNA against Bcl-xL reverses GC induced cytoprotection, Bcl-xL induction represents an important event in GILZ-induced cytoprotection. Our data suggest that GILZ functions as a cytoprotective gene in cardiomyocytes. - Highlights: • Corticosteroids act as a cytoprotective agent in cardiomyocytes • Corticosteroids induce GILZ expression in cardiomyocytes • Elevated GILZ results in resistance against apoptosis induced by doxorubicin • GILZ induces Bcl-xL protein without inducing Bcl-xL mRNA.

  8. The Effects of Leucine, Zinc, and Chromium Supplements on Inflammatory Events of the Respiratory System in Type 2 Diabetic Rats

    PubMed Central

    Kolahian, Saeed; Sadri, Hassan; Shahbazfar, Amir Ali; Amani, Morvarid; Mazadeh, Anis; Mirani, Mehdi

    2015-01-01

    Diabetes mellitus is a major cause of serious micro- and macrovascular diseases that affect nearly every system in the body, including the respiratory system. Non-enzymatic protein glycation due to hyperglycaemic stress has fundamental implications due to the large capillary network and amount of connective tissue in the lung. The current study was designed to determine whether leucine, zinc, and chromium supplementations influence the function and histological structure of the respiratory tract in a rat model of type 2 diabetes. Seventy-seven rats were divided into eleven groups, consisting of 7 animals each. One group served as negative control and insulin and glibenclamide were used as positive control drugs. Thus, eight groups received the nutritional supplements alone or in combination with each other. Nutritional supplements and glibenclamide were added to the drinking water and neutral protamine Hagedorn insulin was subcutaneously injected during the 4 weeks of treatment period. The induction of type 2 diabetes in the rats caused an infiltration of mononuclear cells and edema in the submucosa of the trachea and lung, severe fibrosis around the vessels and airways, and perivascular and peribronchial infiltration of inflammatory cells and fibrin. In the diabetic group, the total inflammation score and Reid index significantly increased. Diabetes induction significantly reduced the total antioxidant status and elevated the lipid peroxidation products in the serum, lung lavage and lung tissue of the diabetic animals. Treatment with nutritional supplements significantly decreased the histopathological changes and inflammatory indices in the diabetic animals. Supplementation of diabetic rats with leucine, zinc, and chromium, alone and in combination, significantly increased the total antioxidant status and lipid peroxidation level in the diabetic animals. The nutritional supplements improved the enzymatic antioxidant activity of catalase, glutathione peroxidase

  9. The Effects of Leucine, Zinc, and Chromium Supplements on Inflammatory Events of the Respiratory System in Type 2 Diabetic Rats.

    PubMed

    Kolahian, Saeed; Sadri, Hassan; Shahbazfar, Amir Ali; Amani, Morvarid; Mazadeh, Anis; Mirani, Mehdi

    2015-01-01

    Diabetes mellitus is a major cause of serious micro- and macrovascular diseases that affect nearly every system in the body, including the respiratory system. Non-enzymatic protein glycation due to hyperglycaemic stress has fundamental implications due to the large capillary network and amount of connective tissue in the lung. The current study was designed to determine whether leucine, zinc, and chromium supplementations influence the function and histological structure of the respiratory tract in a rat model of type 2 diabetes. Seventy-seven rats were divided into eleven groups, consisting of 7 animals each. One group served as negative control and insulin and glibenclamide were used as positive control drugs. Thus, eight groups received the nutritional supplements alone or in combination with each other. Nutritional supplements and glibenclamide were added to the drinking water and neutral protamine Hagedorn insulin was subcutaneously injected during the 4 weeks of treatment period. The induction of type 2 diabetes in the rats caused an infiltration of mononuclear cells and edema in the submucosa of the trachea and lung, severe fibrosis around the vessels and airways, and perivascular and peribronchial infiltration of inflammatory cells and fibrin. In the diabetic group, the total inflammation score and Reid index significantly increased. Diabetes induction significantly reduced the total antioxidant status and elevated the lipid peroxidation products in the serum, lung lavage and lung tissue of the diabetic animals. Treatment with nutritional supplements significantly decreased the histopathological changes and inflammatory indices in the diabetic animals. Supplementation of diabetic rats with leucine, zinc, and chromium, alone and in combination, significantly increased the total antioxidant status and lipid peroxidation level in the diabetic animals. The nutritional supplements improved the enzymatic antioxidant activity of catalase, glutathione peroxidase

  10. Role of glucocorticoid-induced leucine zipper (GILZ) in bone acquisition.

    PubMed

    Pan, Guodong; Cao, Jay; Yang, Nianlan; Ding, Kehong; Fan, Cheng; Xiong, Wen-Cheng; Hamrick, Mark; Isales, Carlos M; Shi, Xing-Ming

    2014-07-11

    Glucocorticoids (GCs) have both anabolic and catabolic effects on bone. However, no GC anabolic effect mediator has been identified to date. Here we show that targeted expression of glucocorticoid-induced leucine zipper (GILZ), a GC anti-inflammatory effect mediator, enhances bone acquisition in mice. Transgenic mice, in which the expression of GILZ is under the control of a 3.6-kb rat type I collagen promoter, exhibited a high bone mass phenotype with significantly increased bone formation rate and osteoblast numbers. The increased osteoblast activity correlates with enhanced osteogenic differentiation and decreased adipogenic differentiation of bone marrow stromal cell cultures in vitro. In line with these changes, the mRNA levels of key osteogenic regulators (Runx2 and Osx) increased, and the level of adipogenic regulator peroxisome proliferator-activated receptor (PPAR) γ2 decreased significantly. We also found that GILZ physically interacts with C/EBPs and disrupts C/EBP-mediated PPARγ gene transcription. In conclusion, our results showed that GILZ is capable of increasing bone acquisition in vivo, and this action is mediated via a mechanism involving the inhibition of PPARγ gene transcription and shifting of bone marrow MSC/progenitor cell lineage commitment in favor of the osteoblast pathway. PMID:24860090

  11. Signal Increase on Unenhanced T1-Weighted Images in the Rat Brain After Repeated, Extended Doses of Gadolinium-Based Contrast Agents

    PubMed Central

    Jost, Gregor; Lenhard, Diana Constanze; Sieber, Martin Andrew; Lohrke, Jessica; Frenzel, Thomas; Pietsch, Hubertus

    2016-01-01

    Objectives In this prospective preclinical study, we evaluated T1-weighted signal intensity in the deep cerebellar nuclei (CN) and globus pallidus (GP) up to 24 days after repeated administration of linear and macrocyclic gadolinium-based contrast agents (GBCAs) using homologous imaging and evaluation methods as in the recently published retrospective clinical studies. In a second part of the study, cerebrospinal fluid (CSF) spaces were evaluated for contrast enhancement by fluid-attenuated magnetic resonance imaging (MRI). Materials and Methods Sixty adult male Wistar-Han rats were randomly divided into a control and 5 GBCA groups (n = 10 per group). The administered GBCAs were gadodiamide, gadopentetate dimeglumine, and gadobenate dimeglumine (linear GBCAs) as well as gadobutrol and gadoterate meglumine (macrocyclic GBCAs) and saline (control). Over a period of 2 weeks, the animals received 10 intravenous injections at a dose of 2.5 mmol Gd/kg body weight, each on 5 consecutive days per week. Before GBCA administration, as well as 3 and 24 days after the last injection, a whole-brain MRI was performed using a standard T1-weighted 3-dimensional turbo spin echo sequence on a clinical 1.5 T scanner. The ratios of signal intensities in deep CN to pons (CN/Po) and GP to thalamus (GP/Th) were determined. For the evaluation of the CSF spaces, 18 additional rats were randomly divided into 6 groups (n = 3 per group) that received the same GBCAs as in the first part of the study. After MR cisternography for anatomical reference, a fluid-attenuated inversion recovery sequence was performed before and 1 minute after intravenous injection of a dose of 1 mmol Gd/kg body weight GBCA or saline. Results A significantly increased signal intensity ratio of CN/Po was observed 3 and 24 days after the last injection of gadodiamide and gadobenate dimeglumine. No significant changes were observed between the 2 time points. Gadopentetate dimeglumine injection led to a moderately elevated

  12. Differential Assimilation of Inorganic Carbon and Leucine by Prochlorococcus in the Oligotrophic North Pacific Subtropical Gyre.

    PubMed

    Björkman, Karin M; Church, Matthew J; Doggett, Joseph K; Karl, David M

    2015-01-01

    The light effect on photoheterotrophic processes in Prochlorococcus, and primary and bacterial productivity in the oligotrophic North Pacific Subtropical Gyre was investigated using (14)C-bicarbonate and (3)H-leucine. Light and dark incubation experiments were conducted in situ throughout the euphotic zone (0-175 m) on nine expeditions to Station ALOHA over a 3-year period. Photosynthetrons were also used to elucidate rate responses in leucine and inorganic carbon assimilation as a function of light intensity. Taxonomic group and cell-specific rates were assessed using flow cytometric sorting. The light:dark assimilation rate ratios of leucine in the top 150 m were ∼7:1 for Prochlorococcus, whereas the light:dark ratios for the non-pigmented bacteria (NPB) were not significant different from 1:1. Prochlorococcus assimilated leucine in the dark at per cell rates similar to the NPB, with a contribution to the total community bacterial production, integrated over the euphotic zone, of approximately 20% in the dark and 60% in the light. Depth-resolved primary productivity and leucine incorporation showed that the ratio of Prochlorococcus leucine:primary production peaked at 100 m then declined steeply below the deep chlorophyll maximum (DCM). The photosynthetron experiments revealed that, for Prochlorococcus at the DCM, the saturating irradiance (E k) for leucine incorporation was reached at approximately half the light intensity required for light saturation of (14)C-bicarbonate assimilation. Additionally, high and low red fluorescing Prochlorococcus populations (HRF and LRF), co-occurring at the DCM, had similar E k values for their respective substrates, however, maximum assimilation rates, for both leucine and inorganic carbon, were two times greater for HRF cells. Our results show that Prochlorococcus contributes significantly to bacterial production estimates using (3)H-leucine, whether or not the incubations are conducted in the dark or light, and this should

  13. Differential Assimilation of Inorganic Carbon and Leucine by Prochlorococcus in the Oligotrophic North Pacific Subtropical Gyre

    PubMed Central

    Björkman, Karin M.; Church, Matthew J.; Doggett, Joseph K.; Karl, David M.

    2015-01-01

    The light effect on photoheterotrophic processes in Prochlorococcus, and primary and bacterial productivity in the oligotrophic North Pacific Subtropical Gyre was investigated using 14C-bicarbonate and 3H-leucine. Light and dark incubation experiments were conducted in situ throughout the euphotic zone (0–175 m) on nine expeditions to Station ALOHA over a 3-year period. Photosynthetrons were also used to elucidate rate responses in leucine and inorganic carbon assimilation as a function of light intensity. Taxonomic group and cell-specific rates were assessed using flow cytometric sorting. The light:dark assimilation rate ratios of leucine in the top 150 m were ∼7:1 for Prochlorococcus, whereas the light:dark ratios for the non-pigmented bacteria (NPB) were not significant different from 1:1. Prochlorococcus assimilated leucine in the dark at per cell rates similar to the NPB, with a contribution to the total community bacterial production, integrated over the euphotic zone, of approximately 20% in the dark and 60% in the light. Depth-resolved primary productivity and leucine incorporation showed that the ratio of Prochlorococcus leucine:primary production peaked at 100 m then declined steeply below the deep chlorophyll maximum (DCM). The photosynthetron experiments revealed that, for Prochlorococcus at the DCM, the saturating irradiance (Ek) for leucine incorporation was reached at approximately half the light intensity required for light saturation of 14C-bicarbonate assimilation. Additionally, high and low red fluorescing Prochlorococcus populations (HRF and LRF), co-occurring at the DCM, had similar Ek values for their respective substrates, however, maximum assimilation rates, for both leucine and inorganic carbon, were two times greater for HRF cells. Our results show that Prochlorococcus contributes significantly to bacterial production estimates using 3H-leucine, whether or not the incubations are conducted in the dark or light, and this should be

  14. Sestrin2 is a leucine sensor for the mTORC1 pathway.

    PubMed

    Wolfson, Rachel L; Chantranupong, Lynne; Saxton, Robert A; Shen, Kuang; Scaria, Sonia M; Cantor, Jason R; Sabatini, David M

    2016-01-01

    Leucine is a proteogenic amino acid that also regulates many aspects of mammalian physiology, in large part by activating the mTOR complex 1 (mTORC1) protein kinase, a master growth controller. Amino acids signal to mTORC1 through the Rag guanosine triphosphatases (GTPases). Several factors regulate the Rags, including GATOR1, aGTPase-activating protein; GATOR2, a positive regulator of unknown function; and Sestrin2, a GATOR2-interacting protein that inhibits mTORC1 signaling. We find that leucine, but not arginine, disrupts the Sestrin2-GATOR2 interaction by binding to Sestrin2 with a dissociation constant of 20 micromolar, which is the leucine concentration that half-maximally activates mTORC1. The leucine-binding capacity of Sestrin2 is required for leucine to activate mTORC1 in cells. These results indicate that Sestrin2 is a leucine sensor for the mTORC1 pathway. PMID:26449471

  15. Sestrin2 is a leucine sensor for the mTORC1 pathway

    PubMed Central

    Wolfson, Rachel L.; Chantranupong, Lynne; Saxton, Robert A.; Shen, Kuang; Scaria, Sonia M.; Cantor, Jason R.; Sabatini, David M.

    2015-01-01

    Leucine is a proteogenic amino acid that also regulates many aspects of mammalian physiology, in large part by activating the mTOR complex 1 (mTORC1) protein kinase, a master growth controller. Amino acids signal to mTORC1 through the Rag guanine triphosphatases (GTPases). Several factors regulate the Rags, including GATOR1, a GTPase activating protein (GAP); GATOR2, a positive regulator of unknown function; and Sestrin2, a GATOR2-interacting protein that inhibits mTORC1 signaling. We find that leucine, but not arginine, disrupts the Sestrin2-GATOR2 interaction by binding to Sestrin2 with a Kd of 20 µM, which is the leucine concentration that half-maximally activates mTORC1. The leucine-binding capacity of Sestrin2 is required for leucine to activate mTORC1 in cells. These results indicate that Sestrin2 is a leucine sensor for the mTORC1 pathway. PMID:26449471

  16. The maternal embryonic leucine zipper kinase (MELK) is upregulated in high-grade prostate cancer.

    PubMed

    Kuner, Ruprecht; Fälth, Maria; Pressinotti, Nicole Chui; Brase, Jan C; Puig, Sabrina Balaguer; Metzger, Jennifer; Gade, Stephan; Schäfer, Georg; Bartsch, Georg; Steiner, Eberhard; Klocker, Helmut; Sültmann, Holger

    2013-02-01

    Loss of cell cycle control is a prerequisite for cancer onset and progression. In prostate cancer, increased activity of cell cycle genes has been associated with prognostic parameters such as biochemical relapse and survival. The identification of novel oncogenic and druggable targets in patient subgroups with poor prognosis may help to develop targeted therapy approaches. We analyzed prostate cancer and corresponding benign tissues (n = 98) using microarrays. The comparison of high- and low-grade tumors (Gleason score ≥ 4 + 3 vs. ≤ 3 + 4) revealed 144 differentially expressed genes (p < 0.05). Out of these, 15 genes were involved in the cell cycle process. The gene maternal embryonic leucine zipper kinase (MELK) was identified to be highly correlated with cell cycle genes like UBE2C, TOP2A, CCNB2, and AURKB. Increased MELK gene expression in high-risk prostate cancer was validated by qPCR in an independent patient cohort (p < 0.005, n = 79). Immunohistochemistry analysis using a tissue microarray (n = 94) revealed increased MELK protein expression in prostate cancer tissues of high Gleason scores. RNAi-based inhibition of MELK in PC3 and LNCaP cells suggested putative function in chromatin modification, embryonic development and cell migration. The concerted inhibition of MELK and other cell cycle targets by the antibiotic siomycin A strongly impaired cell viability of prostate cancer cells, and may point to a novel therapy approach for a subset of high-risk prostate cancer patients. PMID:22945237

  17. Regulation of taste-active components of meat by dietary leucine.

    PubMed

    Imanari, M; Kadowaki, M; Fujimura, S

    2007-04-01

    1. Regulation of meat taste is one effective method for improvement of meat quality. In this study, effects of dietary leucine (Leu) content on taste-active components, especially free glutamate (Glu), in meat were investigated. 2. Broiler chickens (28 d old) were fed on diets with graded dietary Leu content (100, 130 or 150% of Leu requirement in NRC, 1994) for 10 d before marketing. Taste-active components of meat (free amino acids and ATP metabolites) and sensory score of meat soup were estimated. 3. Free Glu content, the main taste-active component of meat, was significantly increased by dietary Leu. Compared with the Leu 130% group, free Glu was increased by 17% in the Leu 100% group. Free Glu of meat tended to decrease in the Leu 150% group. In contrast, inosine monophosphate content in meat did not change among all groups. 4. Sensory evaluation of meat soup from the Leu 100 and 150% groups showed that they had different meat tastes. Sensory scores of overall preference, umami taste and chicken-like taste were significantly higher in the Leu 100% group. 5. These results suggest that dietary Leu content is a regulating factor of free Glu in meat. Decreasing dietary Leu induces an increase in the free Glu content of meat and improves meat taste. PMID:17453808

  18. Acute depletion of plasma glutamine increases leucine oxidation in prednisone-treated humans.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To determine whether depletion in plasma glutamine worsens the catabolic response to corticosteroids, seven healthy volunteers received oral prednisone for 6 days on two separate occasions, at least 2 weeks apart, and in random order. On the sixth day of each treatment course, they received 5 h intr...

  19. Tooth loss is associated with increased risk of esophageal cancer: evidence from a meta-analysis with dose-response analysis

    PubMed Central

    Chen, Qi-Lin; Zeng, Xian-Tao; Luo, Zhi-Xiao; Duan, Xiao-Li; Qin, Jie; Leng, Wei-Dong

    2016-01-01

    Epidemiological studies have revealed the association between tooth loss and the risk of esophageal cancer (EC); however, consistent results were not obtained from different single studies. Therefore, we conducted the present meta-analysis to evaluate the association between tooth loss and EC. We conducted electronic searches of PubMed until to February 10, 2015 to identify relevant observational studies that examined the association between tooth loss and the risk of EC. Study selection and data extraction from eligible studies were independently performed by two authors. The meta-analysis was conducted using Stata 12.0 software. Finally eight eligible publications with ten studies involving 3 cohort studies, 5 case-control studies, and 1 cross-sectional study were yielded. Meta-analysis identified tooth loss increased risk of EC 1.30 times (Relative risk = 1.30, 95% confidence interval = 1.06–1.60, I2 = 13.5%). Dose-response analysis showed linear relationship between tooth loss and risk of EC (RR = 1.01, 95%CI = 1.00–1.03; P for non-linearity test was 0.45). Subgroup analysis proved similar results and publication bias was not detected. In conclusion, tooth loss could be considered to be a significant and dependent risk factor for EC based on the current evidence. PMID:26742493

  20. The local application of a flavonoid, (-)-epicatechin, increases the spiking of globus pallidus neurons in a dose-dependent manner and diminishes the catalepsy induced by haloperidol.

    PubMed

    Alatorre, Alberto; Oviedo-Chávez, Aldo; Villalobos, Nelson; Ríos, Alain; Barrientos, Rafael; Querejeta, Enrique

    2015-02-01

    Flavonoids are natural substances obtained from plants. Most flavonoids cross the blood-brain barrier and exert a wide range of effects on the central nervous system. These actions have been attributed to the modulation of GABA-A receptors. Although motor systems in the central nervous system express a high density of GABA-A receptors, physiological studies about the effects of flavonoids on motor nuclei are scarce. Among the nuclei of the basal ganglia, the globus pallidus is potentially important for the processing of information related to movement. The electrical activity of globus pallidus neurons depends on the GABAergic fibers coming from the striatum and recurrent collateral fibers. It is known that the basal activity of the globus pallidus is modified by blocking dopaminergic receptors. In the present work, we analyzed the effects of the local application of a flavonoid, (-)-epicatechin, on the spiking of globus pallidus neurons in chloral hydrate-anesthetized rats and determined whether (-)-epicatechin applied bilaterally to the globus pallidus can modify the catalepsy induced by systemic administration of haloperidol. The results showed that (-)-epicatechin increased the basal firing of globus pallidus neurons in a dose-dependent manner and antagonized the inhibitory effect of GABA. Bilateral infusion of (-)-epicatechin to the globus pallidus diminished the catalepsy induced by haloperidol. PMID:25503260

  1. Angiotensin II stimulates /sup 3/H-leucine and /sup 3/H-thymidine incorporation in cultured vascular smooth muscle cells

    SciTech Connect

    Dwyer, S.D.; Smith, J.B.

    1987-05-01

    Angiotensin II (ANG) stimulates the hydrolysis of phosphatidylinositol bisphosphate with the consequent formation of inositol trisphosphate and diacylglycerol in cultured smooth muscle cells derived from rat aorta. They have observed the effects of ANG on protein and DNA synthesis by measuring the incorporation of /sup 3/H-leucine and /sup 3/H-thymidine, respectively, into acid-precipitable material. Aortic muscle cells were grown to confluence in medium containing 10% fetal bovine serum (FBS) and incubated for 24 hours in serum-free medium to arrest growth. Then fresh serum-free medium was added with the following additions: ANG (100 nM), insulin (2 ..mu..g/ml), or 10% FBS. After an additional 24 hours the cells were pulse labeled for 30 min with either /sup 3/H-leucine or /sup 3/H-thymidine. FBS increased /sup 3/H-leucine incorporation by -2.5 fold and /sup 3/H-thymidine incorporation by 7-10 fold. ANG or insulin increased /sup 3/H-leucine incorporation by 40-50%, and the combination of ANG and insulin was nearly as effective as 10% FBS. ANG stimulated /sup 3/H-thymidine incorporation by -2.5 fold. Insulin, which was less effective than ANG, increased /sup 3/H-thymidine incorporation by about 50%. ANG and insulin added together synergistically increased /sup 3/H-thymidine incorporation by 5-6 fold. An ANG antagonist, Sarl,leu8-ANG, at 2 ..mu..M markedly decreased /sup 3/H-thymidine incorporation in the presence of ANG and insulin.

  2. Leucine supplementation of a chronically restricted protein and energy diet enhances mTOR pathway activation but not muscle protein synthesis in neonatal pigs.

    PubMed

    Manjarín, Rodrigo; Columbus, Daniel A; Suryawan, Agus; Nguyen, Hanh V; Hernandez-García, Adriana D; Hoang, Nguyet-Minh; Fiorotto, Marta L; Davis, Teresa

    2016-01-01

    Suboptimal nutrient intake represents a limiting factor for growth and long-term survival of low-birth weight infants. The objective of this study was to determine if in neonates who can consume only 70 % of their protein and energy requirements for 8 days, enteral leucine supplementation will upregulate the mammalian target of rapamycin (mTOR) pathway in skeletal muscle, leading to an increase in protein synthesis and muscle anabolism. Nineteen 4-day-old piglets were fed by gastric tube 1 of 3 diets, containing (kg body weight(-1) · day(-1)) 16 g protein and 190 kcal (CON), 10.9 g protein and 132 kcal (R), or 10.8 g protein + 0.2 % leucine and 136 kcal (RL) at 4-h intervals for 8 days. On day 8, plasma AA and insulin levels were measured during 6 post-feeding intervals, and muscle protein synthesis rate and mTOR signaling proteins were determined at 120 min post-feeding. At 120 min, leucine was highest in RL (P < 0.001), whereas insulin, isoleucine and valine were lower in RL and R compared to CON (P < 0.001). Compared to RL and R, the CON diet increased (P < 0.01) body weight, protein synthesis, phosphorylation of S6 kinase (p-S6K1) and 4E-binding protein (p-4EBP1), and activation of eukaryotic initiation factor 4 complex (eIF4E · eIF4G). RL increased (P ≤ 0.01) p-S6K1, p-4EBP1 and eIF4E · eIF4G compared to R. In conclusion, when protein and energy intakes are restricted for 8 days, leucine supplementation increases muscle mTOR activation, but does not improve body weight gain or enhance skeletal muscle protein synthesis in neonatal pigs. PMID:26334346

  3. Kinase domain inhibition of leucine rich repeat kinase 2 (LRRK2) using a [1,2,4]triazolo[4,3-b]pyridazine scaffold.

    PubMed

    Galatsis, Paul; Henderson, Jaclyn L; Kormos, Bethany L; Han, Seungil; Kurumbail, Ravi G; Wager, Travis T; Verhoest, Patrick R; Noell, G Stephen; Chen, Yi; Needle, Elie; Berger, Zdenek; Steyn, Stefanus J; Houle, Christopher; Hirst, Warren D

    2014-09-01

    Leucine rich repeat kinase 2 (LRRK2) has been genetically linked to Parkinson's disease (PD). The most common mutant, G2019S, increases kinase activity, thus LRRK2 kinase inhibitors are potentially useful in the treatment of PD. We herein disclose the structure, potential ligand-protein binding interactions, and pharmacological profiling of potent and highly selective kinase inhibitors based on a triazolopyridazine chemical scaffold. PMID:25113930

  4. Distribution and Evolution of Yersinia Leucine-Rich Repeat Proteins.

    PubMed

    Hu, Yueming; Huang, He; Hui, Xinjie; Cheng, Xi; White, Aaron P; Zhao, Zhendong; Wang, Yejun

    2016-08-01

    Leucine-rich repeat (LRR) proteins are widely distributed in bacteria, playing important roles in various protein-protein interaction processes. In Yersinia, the well-characterized type III secreted effector YopM also belongs to the LRR protein family and is encoded by virulence plasmids. However, little has been known about other LRR members encoded by Yersinia genomes or their evolution. In this study, the Yersinia LRR proteins were comprehensively screened, categorized, and compared. The LRR proteins encoded by chromosomes (LRR1 proteins) appeared to be more similar to each other and different from those encoded by plasmids (LRR2 proteins) with regard to repeat-unit length, amino acid composition profile, and gene expression regulation circuits. LRR1 proteins were also different from LRR2 proteins in that the LRR1 proteins contained an E3 ligase domain (NEL domain) in the C-terminal region or an NEL domain-encoding nucleotide relic in flanking genomic sequences. The LRR1 protein-encoding genes (LRR1 genes) varied dramatically and were categorized into 4 subgroups (a to d), with the LRR1a to -c genes evolving from the same ancestor and LRR1d genes evolving from another ancestor. The consensus and ancestor repeat-unit sequences were inferred for different LRR1 protein subgroups by use of a maximum parsimony modeling strategy. Structural modeling disclosed very similar repeat-unit structures between LRR1 and LRR2 proteins despite the different unit lengths and amino acid compositions. Structural constraints may serve as the driving force to explain the observed mutations in the LRR regions. This study suggests that there may be functional variation and lays the foundation for future experiments investigating the functions of the chromosomally encoded LRR proteins of Yersinia. PMID:27217422

  5. Proteomic analysis of post-nuclear supernatant fraction and percoll-purified membranes prepared from brain cortex of rats exposed to increasing doses of morphine

    PubMed Central

    2014-01-01

    Background Proteomic analysis was performed in post-nuclear supernatant (PNS) and Percoll-purified membranes (PM) prepared from fore brain cortex of rats exposed to increasing doses of morphine (10–50 mg/kg) for 10 days. Results In PNS, the 10 up (↑)- or down (↓)-regulated proteins exhibiting the largest morphine-induced change were selected, excised manually from the gel and identified by MALDI-TOF MS/MS: 1-(gi|148747414, Guanine deaminase), ↑2.5×; 2-(gi|17105370, Vacuolar-type proton ATP subunit B, brain isoform), ↑2.6×; 3-(gi|1352384, Protein disulfide-isomerase A3), ↑3.4×; 4-(gi|40254595, Dihydropyrimidinase-related protein 2), ↑3.6×; 5-(gi|149054470, N-ethylmaleimide sensitive fusion protein, isoform CRAa), ↑2.0×; 6-(gi|42476181, Malate dehydrogenase, mitochondrial precursor), ↑1.4×; 7-(gi|62653546, Glyceraldehyde-3-phosphate dehydrogenase), ↑1.6×; 8-(gi|202837, Aldolase A), ↑1.3×; 9-(gi|31542401, Creatine kinase B-type), ↓0.86×; 10-(gi|40538860, Aconitate hydratase, mitochondrial precursor), ↑1.3×. The identified proteins were of cytoplasmic (1, 4, 5, 7, 9), cell membrane (2), endoplasmic reticulum (3) and mitochondrial (6, 8, 10) origin and 9 of them were significantly increased, 1.3-3.6×. The 4 out of 9 up-regulated proteins (4, 6, 7, 10) were described as functionally related to oxidative stress; the 2 proteins participate in genesis of apoptotic cell death. In PM, the 18 up (↑)- or down (↓)-regulated proteins were identified by LC-MS/MS and were of plasma membrane [Brain acid soluble protein, ↓2.1×; trimeric Gβ subunit, ↓2.0x], myelin membrane [MBP, ↓2.5×], cytoplasmic [Internexin, ↑5.2×; DPYL2, ↑4.9×; Ubiquitin hydrolase, ↓2.0×; 60S ribosomal protein, ↑2.7×; KCRB, ↓2.6×; Sirtuin-2, ↑2.5×; Peroxiredoxin-2, ↑2.2×; Septin-11, ↑2.2×; TERA, ↑2.1×; SYUA, ↑2.0×; Coronin-1A, ↓5.4×] and mitochondrial [Glutamate dehydrogenase 1, ↑2.7×; SCOT1, ↑2.2×; Prohibitin, ↑2.2

  6. Function and dysfunction of leucine-rich repeat kinase 2 (LRRK2): Parkinson's disease and beyond.

    PubMed

    Bae, Jae Ryul; Lee, Byoung Dae

    2015-05-01

    Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common cause of familial Parkinson's disease (PD). As such, functions and dysfunctions of LRRK2 in PD have been the subject of extensive investigation. In addition to PD, increasing evidence is suggesting that LRRK2 is associated with a wide range of diseases. Genome-wide association studies have implicated LRRK2 in Crohn's disease (CD) and leprosy, and the carriers with pathogenic mutations of LRRK2 show increased risk to develop particular types of cancer. LRRK2 mutations are rarely found in Alzheimer's disease (AD), but LRRK2 might play a part in tauopathies. The association of LRRK2 with the pathogenesis of apparently unrelated diseases remains enigmatic, but it might be related to the yet unknown diverse functions of LRRK2. Here, we reviewed current knowledge on the link between LRRK2 and several diseases, including PD, AD, CD, leprosy, and cancer, and discussed the possibility of targeting LRRK2 in such diseases. PMID:25703537

  7. The role of leucine and its metabolites in protein and energy metabolism.

    PubMed

    Duan, Yehui; Li, Fengna; Li, Yinghui; Tang, Yulong; Kong, Xiangfeng; Feng, Zemeng; Anthony, Tracy G; Watford, Malcolm; Hou, Yongqing; Wu, Guoyao; Yin, Yulong

    2016-01-01

    Leucine (Leu) is a nutritionally essential branched-chain amino acid (BCAA) in animal nutrition. It is usually one of the most abundant amino acids in high-quality protein foods. Leu increases protein synthesis through activation of the mammalian target of rapamycin (mTOR) signaling pathway in skeletal muscle, adipose tissue and placental cells. Leu promotes energy metabolism (glucose uptake, mitochondrial biogenesis, and fatty acid oxidation) to provide energy for protein synthesis, while inhibiting protein degradation. Approximately 80 % of Leu is normally used for protein synthesis, while the remainder is converted to α-ketoisocaproate (α-KIC) and β-hydroxy-β-methylbutyrate (HMB) in skeletal muscle. Therefore, it has been hypothesized that some of the functions of Leu are modulated by its metabolites. Both α-KIC and HMB have recently received considerable attention as nutritional supplements used to increase protein synthesis, inhibit protein degradation, and regulate energy homeostasis in a variety of in vitro and in vivo models. Leu and its metabolites hold great promise to enhance the growth and health of animals (including humans, birds and fish). PMID:26255285

  8. The role and effects of glucocorticoid-induced leucine zipper in the context of inflammation resolution.

    PubMed

    Vago, Juliana P; Tavares, Luciana P; Garcia, Cristiana C; Lima, Kátia M; Perucci, Luiza O; Vieira, Érica L; Nogueira, Camila R C; Soriani, Frederico M; Martins, Joilson O; Silva, Patrícia M R; Gomes, Karina B; Pinho, Vanessa; Bruscoli, Stefano; Riccardi, Carlo; Beaulieu, Elaine; Morand, Eric F; Teixeira, Mauro M; Sousa, Lirlândia P

    2015-05-15

    Glucocorticoid (GC)-induced leucine zipper (GILZ) has been shown to mediate or mimic several actions of GC. This study assessed the role of GILZ in self-resolving and GC-induced resolution of neutrophilic inflammation induced by LPS in mice. GILZ expression was increased during the resolution phase of LPS-induced pleurisy, especially in macrophages with resolving phenotypes. Pretreating LPS-injected mice with trans-activator of transcription peptide (TAT)-GILZ, a cell-permeable GILZ fusion protein, shortened resolution intervals and improved resolution indices. Therapeutic administration of TAT-GILZ induced inflammation resolution, decreased cytokine levels, and promoted caspase-dependent neutrophil apoptosis. TAT-GILZ also modulated the activation of the survival-controlling proteins ERK1/2, NF-κB and Mcl-1. GILZ deficiency was associated with an early increase of annexin A1 (AnxA1) and did not modify the course of neutrophil influx induced by LPS. Dexamethasone treatment resolved inflammation and induced GILZ expression that was dependent on AnxA1. Dexamethasone-induced resolution was not altered in GILZ(-/-) mice due to compensatory expression and action of AnxA1. Our results show that therapeutic administration of GILZ efficiently induces a proapoptotic program that promotes resolution of neutrophilic inflammation induced by LPS. Alternatively, a lack of endogenous GILZ during the resolution of inflammation is compensated by AnxA1 overexpression. PMID:25876761

  9. Generating and using patient-specific whole-body models for organ dose estimates in CT with increased accuracy: feasibility and validation.

    PubMed

    Kalender, Willi A; Saltybaeva, Natalia; Kolditz, Daniel; Hupfer, Martin; Beister, Marcel; Schmidt, Bernhard

    2014-12-01

    The estimation of patient dose using Monte Carlo (MC) simulations based on the available patient CT images is limited to the length of the scan. Software tools for dose estimation based on standard computational phantoms overcome this problem; however, they are limited with respect to taking individual patient anatomy into account. The purpose of this study was to generate whole-body patient models in order to take scattered radiation and over-scanning effects into account. Thorax examinations were performed on three physical anthropomorphic phantoms at tube voltages of 80 kV and 120 kV; absorbed dose was measured using thermoluminescence dosimeters (TLD). Whole-body voxel models were built as a combination of the acquired CT images appended by data taken from widely used anthropomorphic voxel phantoms. MC simulations were performed both for the CT image volumes alone and for the whole-body models. Measured and calculated dose distributions were compared for each TLD chip position; additionally, organ doses were determined. MC simulations based only on CT data underestimated dose by 8%-15% on average depending on patient size with highest underestimation values of 37% for the adult phantom at the caudal border of the image volume. The use of whole-body models substantially reduced these errors; measured and simulated results consistently agreed to better than 10%. This study demonstrates that combined whole-body models can provide three-dimensional dose distributions with improved accuracy. Using the presented concept should be of high interest for research studies which demand high accuracy, e.g. for dose optimization efforts. PMID:25288527

  10. SU-F-BRF-14: Increasing the Accuracy of Dose Calculation On Cone-Beam Imaging Using Deformable Image Registration in the Case of Prostate Translation

    SciTech Connect

    Fillion, O; Gingras, L; Archambault, L

    2014-06-15

    Purpose: Artifacts can reduce the quality of dose re-calculations on CBCT scans during a treatment. The aim of this project is to correct the CBCT images in order to allow for more accurate and exact dose calculations in the case of a translation of the tumor in prostate cancer. Methods: Our approach is to develop strategies based on deformable image registration algorithms using the elastix software (Klein et al., 2010) to register the treatment planning CT on a daily CBCT scan taken during treatment. Sets of images are provided by a 3D deformable phantom and comprise two CT and two CBCT scans: one of both with the reference anatomy and the others with known deformations (i.e. translations of the prostate). The reference CT is registered onto the deformed CBCT and the deformed CT serves as the control for dose calculation accuracy. The planned treatment used for the evaluation of dose calculation is a 2-Gy fraction prescribed at the location of the reference prostate and assigned to 7 rectangular fields. Results: For a realistic 0.5-cm translation of the prostate, the relative dose discrepancy between the CBCT and the CT control scan at the prostate's centroid is 8.9 ± 0.8 % while dose discrepancy between the registered CT and the control scan lessens to −2.4 ± 0.8 %. For a 2-cm translation, clinical indices like the V90 and the D100 are more accurate by 0.7 ± 0.3 % and 8.0 ± 0.5 cGy respectively when using registered CT than when using CBCT for dose calculation. Conclusion: The results show that this strategy gives doses in agreement within a few percents with those from calculations on actual CT scans. In the future, various deformations of the phantom anatomy will allow a thorough characterization of the registration strategies needed for more complex anatomies.

  11. Simulations of potentials of mean force for separating a leucine zipper dimer and the basic region of a basic region leucine zipper dimer.

    PubMed

    Cukier, Robert I

    2014-09-01

    Basic region leucine zipper (bZIP) transcription factors involved in DNA recognition are dimeric proteins. The monomers consist of two subdomains, a leucine zipper sequence responsible for dimerization and a highly basic DNA recognition sequence. Leucine zippers are strongly dimerized, and in a bZIP, the basic region can, in the absence of DNA, undergo extensive relative monomer-to-monomer fluctuations. In this work, LZ and bZIP potentials of mean force (PMFs), which provide free energies along reaction coordinates, are simulated with a distance replica exchange method. The method uses restraint potentials to provide sampling along a reaction coordinate and enhances configuration space exploration by exchanging information between neighboring restraint potential configurations. Restraint potentials that are constructed from sums over a number of atom distances are employed. Their use requires a modification of the Weighted Histogram Analysis Method (WHAM) procedure to combine and unbias the data from the different restraint-potential-biased window densities to provide a PMF. These methods are first used to obtain a PMF for separating a leucine zipper (GCN4-p1) of the yeast transcriptional activator GCN4. The PMF indicates a very strong binding free energy that only weakens when the monomers are separated by about 12 Å, which is about 6 Å beyond their bound, dimer equilibrium distance. PMFs are also obtained for separating the basic subdomain monomer parts of the GCN4 bZIP transcriptional factor, in the absence of DNA. In a monomer separation range spanning the open, crystal-based structure to closer configurations, the basic subdomain PMF is quite flat, implying essentially thermal sampling in this distance range. A PMF generated starting from a "collapsed" state, taken from a previous simulation ( J. Phys. Chem. B 2012 , 116 , 6071 ), where collapsed refers to the feature that the basic subdomain monomers are also effectively dimerized, shows that this state is

  12. MODEL-BASED ITERATIVE RECONSTRUCTION ENABLES THE EVALUATION OF THIN-SLICE COMPUTED TOMOGRAPHY IMAGES WITHOUT DEGRADING IMAGE QUALITY OR INCREASING RADIATION DOSE.

    PubMed

    Aurumskjöld, Marie-Louise; Ydström, Kristina; Tingberg, Anders; Söderberg, Marcus

    2016-06-01

    Computed tomography (CT) is one of the most important modalities in a radiological department. This technique not only produces images that enable radiological reports with high diagnostic confidence, but it may also provide an elevated radiation dose to the patient. The radiation dose can be reduced by using advanced image reconstruction algorithms. This study was performed on a Brilliance iCT, equipped with iDose(4) iterative reconstruction and an iterative model-based reconstruction (IMR) method. The purpose was to investigate the effect of reduced slice thickness combined with an IMR method on image quality compared with standard slice thickness with iDose(4) reconstruction. The results of objective and subjective image quality evaluations showed that a thinner slice combined with IMR can improve the image quality and reduce partial volume artefacts compared with the standard slice thickness with iDose(4) In conclusion, IMR enables reduction of the slice thickness while maintaining or even improving image quality versus iDose(4). PMID:26590394

  13. A single dose of vortioxetine, but not ketamine or fluoxetine, increases plasticity-related gene expression in the rat frontal cortex.

    PubMed

    du Jardin, Kristian Gaarn; Müller, Heidi Kaastrup; Sanchez, Connie; Wegener, Gregers; Elfving, Betina

    2016-09-01

    Ketamine is a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist that has been shown to induce a rapid antidepressant effect in treatment-resistant patients. Vortioxetine is a multimodal-acting antidepressant that exert its therapeutic activity through serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibition and modulation of several 5-HT receptors. In clinical trials, vortioxetine improves depression symptoms and cognitive dysfunction. Neuroplasticity as well as serotonergic and glutamatergic signaling attain significant roles in depression pathophysiology and antidepressant responses. Here, we investigate the effects of ketamine and vortioxetine on gene expression related to serotonergic and glutamatergic neurotransmission as well as neuroplasticity and compare them to those of the selective serotonin reuptake inhibitor fluoxetine. Rats were injected with fluoxetine (10mg/kg), ketamine (15mg/kg), or vortioxetine (10mg/kg) at 2, 8, 12, or 27h prior to harvesting of the frontal cortex and hippocampus. mRNA levels were measured by real-time quantitative polymerase chain reaction (qPCR). The main finding was that vortioxetine enhanced plasticity-related gene expression (Mtor, Mglur1, Pkcα, Homer3, Spinophilin, and Synapsin3) in the frontal cortex at 8h after a single dose. Ingenuity pathway analysis of this subset of data identified a biological network that was engaged by vortioxetine and is plausibly associated with neuroplasticity. Transcript levels had returned to baseline levels 12h after injection. Only minor effects on gene expression were found for ketamine or fluoxetine. In conclusion, acute vortioxetine, but not fluoxetine or ketamine, transiently increased plasticity-related gene expression in the frontal cortex. These effects may be ascribed to the direct 5-HT receptor activities of vortioxetine. PMID:27235984

  14. Delivering a “Dose of Hope”: A Faith-Based Program to Increase Older African Americans’ Participation in Clinical Trials

    PubMed Central

    Omer, Saad B; Parker, Kimberly; Bolton, Marcus; Schamel, Jay; Shapiro, Eve; Owens, Lauren; Saint-Victor, Diane; Boggavarapu, Sahithi; Braxton, Nikia; Archibald, Matthew; Kalokhe, Ameeta S; Horton, Takeia; Root, Christin M; Fenimore, Vincent L; Anderson, Aaron M

    2015-01-01

    Background Underrepresentation of older-age racial and ethnic minorities in clinical research is a significant barrier to health in the United States, as it impedes medical research advancement of effective preventive and therapeutic strategies. Objective The objective of the study was to develop and test the feasibility of a community-developed faith-based intervention and evaluate its potential to increase the number of older African Americans in clinical research. Methods Using a cluster-randomized design, we worked with six matched churches to enroll at least 210 persons. We provided those in the intervention group churches with three educational sessions on the role of clinical trials in addressing health disparity topics, and those in the comparison group completed surveys at the same timepoints. All persons enrolled in the study received ongoing information via newsletters and direct outreach on an array of clinical studies seeking participants. We evaluated the short-, mid-, and longer-term effects of the interventional program on clinical trial-related outcomes (ie, screening and enrollment). Results From 2012 to 2013, we enrolled a balanced cohort of 221 persons in the program. At a 3-month follow-up, mean intention to seek information about clinical trials was higher than baseline in both treatment (mu=7.5/10; sigma=3.1) and control arms (mu=6.6/10; sigma=3.3), with the difference more pronounced in the treatment arm. The program demonstrated strong retention at 3-month (95.4%, 211/221) and 6-month timepoints (94.1%, 208/221). Conclusions The “Dose of Hope” program addressed an unmet need to reach an often overlooked audience of older African Americans who are members of churches and stimulate their interest in clinical trial participation. The program demonstrated its appeal in the delivery of effective messages and information about health disparities, and the role of clinical research in addressing these challenges. PMID:26036841

  15. Influence of the Valine Zipper Region on the Structure and Aggregation of the Basic Leucine Zipper (bZIP) Domain of Activating Transcription Factor 5 (ATF5)

    PubMed Central

    Ciaccio, Natalie A.; Reynolds, T. Steele; Middaugh, C. Russell; Laurence, Jennifer S.

    2012-01-01

    Protein aggregation is a major problem for biopharmaceuticals. While the control of aggregation is critically important for the future of protein pharmaceuticals, mechanisms of aggregate assembly, particularly the role that structure plays, are still poorly understood. Increasing evidence indicates that partially folded intermediates critically influence the aggregation pathway. We have previously reported the use of the basic leucine zipper (bZIP) domain of Activating Transcription Factor 5 (ATF5) as a partially folded model system to investigate protein aggregation. This domain contains three regions with differing structural propensity: a N-terminal polybasic region, a central helical leucine zipper region, and a C-terminal extended valine zipper region. Additionally, a centrally positioned cysteine residue readily forms an intermolecular disulfide bond that reduces aggregation. Computational analysis of ATF5 predicts that the valine zipper region facilitates self-association. Here we test this hypothesis using a truncated mutant lacking the C-terminal valine zipper region. We compare the structure and aggregation of this mutant to the wild-type (WT) form under both reducing and non-reducing conditions. Our data indicate that removal of this region results in a loss of alpha-helical structure in the leucine zipper and a change in the mechanism of self-association. The mutant form displays increased association at low temperature but improved resistance to thermally induced aggregation. PMID:23067245

  16. The mechanism of transfer for L-leucine into the vascular bed of the Anuran small intestine.

    PubMed Central

    Cheeseman, C I

    1981-01-01

    1. The vascularly perfused small intestine of Rana pipiens was used to investigate the movement of the amino acid L-leucine from the epithelium into the vascular bed. It was found that only a few amino acids when present in the lumen inhibited the wash-out leucine into the vascular bed. The series of amino acids which had this effect belonged to the group previously shown to be transported by 'L-type' carrier systems. 2. Nearly all amino acids when present in the lumen accelerated the flux of leucine from the vascular bed to the lumen and there was little correlation between the amino acids which caused this effect and those which inhibited leucine wash-out into the vascular bed. Replacement of luminal sodium also promoted serosal-to-mucosal leucine flux. 3. The effect of the presence of amino acids in the lumen on the uptake of leucine from the vascular bed was measured using a fractional extraction technique; sucrose was the extracellular marker. There was complete correlation between the amino acids which promoted the extraction of leucine from the vascular bed and those which inhibited leucine wash-out into the vascular bed. 4. In contrast, the wash-out of leucine into the vascular bed was not accelerated by the addition of amino acids to the vascular perfusate, and the presence of 10 mM-leucine in the vascular bed had very little effect upon the mucosal-to-serosal flux of leucine. 5. These results are discussed with regard to the specificity of an exit system for leucine, in the intestinal epithelium, which appears to have an energy requirement. PMID:6975822

  17. Reevaluation of Phosphorylation Sites in the Parkinson Disease-associated Leucine-rich Repeat Kinase 2*

    PubMed Central

    Li, Xiaojie; Moore, Darren J.; Xiong, Yulan; Dawson, Ted M.; Dawson, Valina L.

    2010-01-01

    Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene have been identified as an important cause of late-onset, autosomal dominant familial Parkinson disease and contribute to sporadic Parkinson disease. LRRK2 is a large complex protein with multiple functional domains, including a Roc-GTPase, protein kinase, and multiple protein-protein interaction domains. Previous studies have suggested an important role for kinase activity in LRRK2-induced neuronal toxicity and inclusion body formation. Disease-associated mutations in LRRK2 also tend to increase kinase activity. Thus, enhanced kinase activity may therefore underlie LRRK2-linked disease. Similar to the closely related mixed-lineage kinases, LRRK2 can undergo autophosphorylation in vitro. Three putative autophosphorylation sites (Thr-2031, Ser-2032, and Thr-2035) have been identified within the activation segment of the LRRK2 kinase domain based on sequence homology to mixed-lineage kinases. Phosphorylation at one or more of these sites is critical for the kinase activity of LRRK2. Sensitive phopho-specific antibodies to each of these three sites have been developed and validated by ELISA, dot-blot, and Western blot analysis. Using these antibodies, we have found that all three putative sites are phosphorylated in LRRK2, and Ser-2032 and Thr-2035 are the two important sites that regulate LRRK2 kinase activity. PMID:20595391

  18. Dual leucine zipper kinase is required for excitotoxicity-induced neuronal degeneration

    PubMed Central

    Pozniak, Christine D.; Sengupta Ghosh, Arundhati; Gogineni, Alvin; Hanson, Jesse E.; Lee, Seung-Hye; Larson, Jessica L.; Solanoy, Hilda; Bustos, Daisy; Li, Hong; Ngu, Hai; Jubb, Adrian M.; Ayalon, Gai; Wu, Jiansheng; Scearce-Levie, Kimberly; Zhou, Qiang; Weimer, Robby M.; Kirkpatrick, Donald S.

    2013-01-01

    Excessive glutamate signaling is thought to underlie neurodegeneration in multiple contexts, yet the pro-degenerative signaling pathways downstream of glutamate receptor activation are not well defined. We show that dual leucine zipper kinase (DLK) is essential for excitotoxicity-induced degeneration of neurons in vivo. In mature neurons, DLK is present in the synapse and interacts with multiple known postsynaptic density proteins including the scaffolding protein PSD-95. To examine DLK function in the adult, DLK-inducible knockout mice were generated through Tamoxifen-induced activation of Cre-ERT in mice containing a floxed DLK allele, which circumvents the neonatal lethality associated with germline deletion. DLK-inducible knockouts displayed a modest increase in basal synaptic transmission but had an attenuation of the JNK/c-Jun stress response pathway activation and significantly reduced neuronal degeneration after kainic acid–induced seizures. Together, these data demonstrate that DLK is a critical upstream regulator of JNK-mediated neurodegeneration downstream of glutamate receptor hyper-activation and represents an attractive target for the treatment of indications where excitotoxicity is a primary driver of neuronal loss. PMID:24166713

  19. Maternal embryonic leucine zipper kinase regulates pancreatic ductal, but not β-cell, regeneration.

    PubMed

    Chung, Cheng-Ho; Miller, Amber; Panopoulos, Andreas; Hao, Ergeng; Margolis, Robert; Terskikh, Alexey; Levine, Fred

    2014-09-01

    The maternal embryonic leucine zipper kinase (MELK) is expressed in stem/progenitor cells in some adult tissues, where it has been implicated in diverse biological processes, including the control of cell proliferation. Here, we described studies on its role in adult pancreatic regeneration in response to injury induced by duct ligation and β-cell ablation. MELK expression was studied using transgenic mice expressing GFP under the control of the MELK promoter, and the role of MELK was studied using transgenic mice deleted in the MELK kinase domain. Pancreatic damage was initiated using duct ligation and chemical beta-cell ablation. By tracing MELK expression using a MELK promoter-GFP transgene, we determined that expression was extremely low in the normal pancreas. However, following duct ligation and β-cell ablation, it became highly expressed in pancreatic ductal cells while remaining weakly expressed in α-cells and β- cells. In a mutant mouse in which the MELK kinase domain was deleted, there was no effect on pancreatic development. There was no apparent effect on islet regeneration, either. However, following duct ligation there was a dramatic increase in the number of small ducts, but no change in the total number of duct cells or duct cell proliferation. In vitro studies indicated that this was likely due to a defect in cell migration. These results implicate MELK in the control of the response of the pancreas to injury, specifically controlling cell migration in normal and transformed pancreatic duct cells. PMID:25194022

  20. The Importance of Being Flexible: The Case of Basic Region Leucine Zipper Transcriptional Regulators

    PubMed Central

    Miller, Maria

    2009-01-01

    Large volumes of protein sequence and structure data acquired by proteomic studies led to the development of computational bioinformatic techniques that made possible the functional annotation and structural characterization of proteins based on their primary structure. It has become evident from genome-wide analyses that many proteins in eukaryotic cells are either completely disordered or contain long unstructured regions that are crucial for their biological functions. The content of disorder increases with evolution indicating a possibly important role of disorder in the regulation of cellular systems. Transcription factors are no exception and several proteins of this class have recently been characterized as premolten/molten globules. Yet, mammalian cells rely on these proteins to control expression of their 30,000 or so genes. Basic region:leucine zipper (bZIP) DNA-binding proteins constitute a major class of eukaryotic transcriptional regulators. This review discusses how conformational flexibility “built” into the amino acid sequence allows bZIP proteins to interact with a large number of diverse molecular partners and to accomplish their manifold cellular tasks in a strictly regulated and coordinated manner. PMID:19519454

  1. Anti-leucine-rich glioma-inactivated 1 limbic encephalitis: A case report and literature review

    PubMed Central

    LIU, JINGYAO; LI, MIN; LI, GUIBO; ZHOU, CHUNKUI; ZHANG, RENSHENG

    2016-01-01

    This study describes the case of a 41-year-old woman admitted for anterograde memory loss, right facial grimacing and right arm posturing that had begun 1 month previously. Cranial magnetic resonance-diffusion weighted imaging and -fluid-attenuated inversion recovery imaging revealed a hyperintense signal in the left hippocampus and right basal ganglia, but no contrast enhancement. An electroencephalogram revealed rhythmic sharp and slow waves and rhythmic θ build-ups in the left temporal area. Single-photon emission computed tomography showed increased regional blood flow perfusion in the left cerebral frontal lobe and the right basal ganglia. The cerebrospinal fluid was normal, with the exception of the presence of leucine-rich glioma-inactivated 1 (LGI1) antibodies, and LGI1 antibodies were also found in the blood serum. The presence of the antibodies, the faciobrachial dystonic seizures (FBDSs) and the memory loss indicated limbic encephalitis. After 3 months of immunotherapy, the patient was free from epileptic seizures and had undergone a partial memory restoration. FBDSs alone justify the immediate initiation of immunotherapy, even prior to laboratory confirmation of the disease, as early treatment limits the duration of the illness. PMID:26889260

  2. Reviewing the Effects of l-Leucine Supplementation in the Regulation of Food Intake, Energy Balance, and Glucose Homeostasis

    PubMed Central

    Pedroso, João A.B.; Zampieri, Thais T.; Donato, Jose

    2015-01-01

    Leucine is a well-known activator of the mammalian target of rapamycin (mTOR). Because mTOR signaling regulates several aspects of metabolism, the potential of leucine as a dietary supplement for treating obesity and diabetes mellitus has been investigated. The objective of the present review was to summarize and discuss the available evidence regarding the mechanisms and the effects of leucine supplementation on the regulation of food intake, energy balance, and glucose homeostasis. Based on the available evidence, we conclude that although central leucine injection decreases food intake, this effect is not well reproduced when leucine is provided as a dietary supplement. Consequently, no robust evidence indicates that oral leucine supplementation significantly affects food intake, although several studies have shown that leucine supplementation may help to decrease body adiposity in specific conditions. However, more studies are necessary to assess the effects of leucine supplementation in already-obese subjects. Finally, although several studies have found that leucine supplementation improves glucose homeostasis, the underlying mechanisms involved in these potential beneficial effects remain unknown and may be partially dependent on weight loss. PMID:26007339

  3. IGFBP-1 hyperphosphorylation in response to leucine deprivation is mediated by the AAR pathway.

    PubMed

    Malkani, Niyati; Jansson, Thomas; Gupta, Madhulika B

    2015-09-01

    Insulin-like growth factor-1 (IGF-I) is the key regulator of fetal growth. IGF-I bioavailability is markedly diminished by IGF binding protein-1 (IGFBP-1) phosphorylation. Leucine deprivation strongly induces IGFBP-1 hyperphosphorylation, and plays an important role in fetal growth restriction (FGR). FGR is characterized by decreased amino acid availability, which activates the amino acid response (AAR) and inhibits the mechanistic target of rapamycin (mTOR) pathway. We investigated the role of AAR and mTOR in mediating IGFBP-1 secretion and phosphorylation in HepG2 cells in leucine deprivation. mTOR inhibition (rapamycin or raptor + rictor siRNA), or activation (DEPTOR siRNA) demonstrated a role of mTOR in leucine deprivation-induced IGFBP-1 secretion but not phosphorylation. When the AAR was blocked (U0126, or ERK/GCN2 siRNA), both IGFBP-1 secretion and hyperphosphorylation (pSer101/pSer119/pSer169) due to leucine deprivation were prevented. CK2 inhibition by TBB also attenuated IGFBP-1 phosphorylation in leucine deprivation. These results suggest that the AAR and mTOR independently regulate IGFBP-1 secretion and phosphorylation in response to decreased amino acid availability. PMID:25957086

  4. Incorporation and release of tritiated leucine in rat prostate during castration induced involution

    SciTech Connect

    Bockrath, J.M.; Lee, C.; Grayhack, J.T.

    1981-11-01

    Rates of 3H-leucine incorporation into and release from the ventral prostate during castration induced involution were studied in adult male rats. We measured the rate of 3H-leucine incorporation by incubating the prostatic tissue in medium 199 containing 3H-leucine at 37 C for 1 hour. The rate of radioactivity incorporated into the protein fraction was expressed as cpm mg of protein. This rate reduced linearly from Day 0 to Day 6 post castration. Subcutaneous implantation of a silastic capsule containing crystalline testosterone to castrated rats restored the rate of incorporation to that of sham operated rats. To study the rate of 3H-leucine release, 3H-leucine prepared in 0.9 per cent Na C1 solution was injected intravenously into rats 1 day before castration. The amount of radioactivity remaining in the protein fraction of the prostate, expressed as cpm per prostate, was measured at different intervals after castration or after sham operation. Radioactivity disappeared at a significantly faster rate in the prostate of castrated rats than in sham operated controls. Testosterone replacement to castrated rats delayed the rate of loss of radioactivity to a degree similar to that of sham operated rats. These findings indicate that the rapid rate of protein loss in the regressing prostate is the result of a combined action of an accelerated rate of protein degradation and a rate of protein synthesis. Testosterone administration reversed these patterns of protein metabolism.

  5. Amperometric bienzyme screen-printed biosensor for the determination of leucine.

    PubMed

    Labroo, Pratima; Cui, Yue

    2014-01-01

    Leucine plays an important role in protein synthesis, brain functions, building muscle mass, and helping the body when it undergoes stress. Here, we report a new amperometric bienzyme screen-printed biosensor for the determination of leucine, by coimmobilizing p-hydroxybenzoate hydroxylase (HBH) and leucine dehydrogenase (LDH) on a screen-printed electrode with NADP(+) and p-hydroxybenzoate as the cofactors. The detection principle of the sensor is that LDH catalyzes the specific dehydrogenation of leucine by using NADP(+) as a cofactor. The product, NADPH, triggers the hydroxylation of p-hydroxybenzoate by HBH in the presence of oxygen to produce 3,4-dihydroxybenzoate, which results in a change in electron concentration at the working carbon electrode, which is detected by the potentiostat. The sensor shows a linear detection range between 10 and 600 μM with a detection limit of 2 μM. The response is reproducible and has a fast measuring time of 5-10 s after the addition of a given concentration of leucine. PMID:24220759

  6. Bacterial incorporation of leucine into protein down to -20 degrees C with evidence for potential activity in sub-eutectic saline ice formations.

    PubMed

    Junge, Karen; Eicken, Hajo; Swanson, Brian D; Deming, Jody W

    2006-06-01

    Direct evidence for metabolism in a variety of frozen environments has pushed temperature limits for bacterial activity to increasingly lower temperatures, so far to -20 degrees C. To date, the metabolic activities of marine psychrophilic bacteria, important components of sea-ice communities, have not been studied in laboratory culture, not in ice and not below -12 degrees C. We measured [3H]-leucine incorporation into macromolecules (further fractionated biochemically) by the marine psychrophilic bacterium Colwellia psychrerythraea strain 34H over a range of anticipated activity-permissive temperatures, from +13 to -20 degrees C, including expected negative controls at -80 and -196 degrees C. For incubation temperatures below -1 degrees C, the cell suspensions [all in artificial seawater (ASW)] were first quick-frozen in liquid nitrogen. We also examined the effect of added extracellular polymeric substances (EPS) on [3H]-leucine incorporation. Results showed that live cells of strain 34H incorporated substantial amounts of [3H]-leucine into TCA-precipitable material (primarily protein) down to -20 degrees C. At temperatures from -1 to -20 degrees C, rates were enhanced by EPS. No activity was detected in the killed controls for strain 34H (or in Escherichia coli controls), which included TCA-killed, heat-killed, and sodium azide- and chloramphenicol-treated samples. Surprisingly, evidence for low but significant rates of intracellular incorporation of [3H]-leucine into protein was observed for both ASW-only and EPS-amended (and live only) samples incubated at -80 and -196 degrees C. Mechanisms that could explain the latter results require further study, but the process of vitrification promoted by rapid freezing and the presence of salts and organic polymers may be relevant. Overall, distinguishing between intracellular and extracellular aspects of bacterial activity appears important to understanding behavior at sub-freezing temperatures. PMID:16647051

  7. Leucine-684: A conserved residue of an AMP-acetyl CoA synthetase (AceCS) from Leishmania donovani is involved in substrate recognition, catalysis and acetylation.

    PubMed

    Soumya, Neelagiri; Tandan, Hitendra; Damre, Mangesh V; Gangwal, Rahul P; Sangamwar, Abhay T; Singh, Sushma

    2016-04-15

    AMP-acetyl CoA synthetase (AMP-AceCS) is a key enzyme which catalyzes the activation of acetate to acetyl CoA, an important intermediate at the cross roads of various anabolic and catabolic pathways. Multiple sequence alignment of Leishmania donovani AceCS with other organisms revealed the presence of a highly conserved leucine residue at 684 position which is known to be crucial for acetylation by protein acetyl transferases in other organisms. In an attempt to understand the role of leucine residue at 684 position in L. donovani acetyl CoA synthetase (LdAceCS), it was mutated to proline (P) by site directed mutagenesis. Kinetic analysis of the L684P-LdAceCS mutant revealed approximately two fold increased binding affinity with acetate, whereas fivefold decreased affinity was observed with ATP. There was insignificant change in secondary structure as revealed by CD however, two fold decreased fluorescence intensity was observed at an emission maxima of 340nm. Interestingly, L684P mutation abolished the acetylation of the mutant enzyme indicating the importance of L684 in acetylation of the enzyme. Changes in biochemical parameters of the mutant protein were validated by homology modeling of the wild type and mutant LdAceCS enzyme using Salmonella enterica AceCS crystal structure as template. Our data provides evidence for the role of leucine 684 residue in substrate recognition, catalysis and acetylation of the AceCS enzyme. PMID:26794803

  8. Light Conditions Affect the Measurement of Oceanic Bacterial Production via Leucine Uptake

    PubMed Central

    Morán, Xosé Anxelu G.; Massana, Ramon; Gasol, Josep M.

    2001-01-01

    The effect of irradiance in the range of 400 to 700 nm or photosynthetically active radiation (PAR) on bacterial heterotrophic production estimated by the incorporation of 3H-leucine (referred to herein as Leu) was investigated in the northwestern Mediterranean Sea and in a coastal North Atlantic site, with Leu uptake rates ranging over 3 orders of magnitude. We performed in situ incubations under natural irradiance levels of Mediterranean samples taken from five depths around solar noon and compared them to incubations in the dark. In two of the three stations large differences were found between light and dark uptake rates for the surfacemost samples, with dark values being on average 133 and 109% higher than in situ ones. Data obtained in coastal North Atlantic waters confirmed that dark enclosure may increase Leu uptake rates more than threefold. To explain these differences, on-board experiments of Leu uptake versus irradiance were performed with Mediterranean samples from depths of 5 and 40 m. Incubations under a gradient of 12 to 1,731 μmol of photons m−2 s−1 evidenced a significant increase in incorporation rates with increasing PAR in most of the experiments, with dark-incubated samples departing from this pattern. These results were not attributed to inhibition of Leu uptake in the light but to enhanced bacterial response when transferred to dark conditions. The ratio of dark to light uptake rates increased as dissolved inorganic nitrogen concentrations decreased, suggesting that bacterial nutrient deficiency was overcome by some process occurring only in the dark bottles. PMID:11525969

  9. Maternal embryonic leucine zipper kinase (MELK) reduces replication stress in glioblastoma cells.

    PubMed

    Kig, Cenk; Beullens, Monique; Beke, Lijs; Van Eynde, Aleyde; Linders, Johannes T; Brehmer, Dirk; Bollen, Mathieu

    2013-08-16

    Maternal embryonic leucine zipper kinase (MELK) belongs to the subfamily of AMP-activated Ser/Thr protein kinases. The expression of MELK is very high in glioblastoma-type brain tumors, but it is not clear how this contributes to tumor growth. Here we show that the siRNA-mediated loss of MELK in U87 MG glioblastoma cells causes a G1/S phase cell cycle arrest accompanied by cell death or a senescence-like phenotype that can be rescued by the expression of siRNA-resistant MELK. This cell cycle arrest is mediated by an increased expression of p21(WAF1/CIP1), an inhibitor of cyclin-dependent kinases, and is associated with the hypophosphorylation of the retinoblastoma protein and the down-regulation of E2F target genes. The increased expression of p21 can be explained by the consecutive activation of ATM (ataxia telangiectasia mutated), Chk2, and p53. Intriguingly, the activation of p53 in MELK-deficient cells is not due to an increased stability of p53 but stems from the loss of MDMX (mouse double minute-X), an inhibitor of p53 transactivation. The activation of the ATM-Chk2 pathway in MELK-deficient cells is associated with the accumulation of DNA double-strand breaks during replication, as demonstrated by the appearance of γH2AX foci. Replication stress in these cells is also illustrated by an increased number of stalled replication forks and a reduced fork progression speed. Our data indicate that glioblastoma cells have elevated MELK protein levels to better cope with replication stress during unperturbed S phase. Hence, MELK inhibitors hold great potential for the treatment of glioblastomas as such or in combination with DNA-damaging therapies. PMID:23836907

  10. [State of the organ of vision and behavior of rats after action on the eye of increased doses of UV-irradiation].

    PubMed

    Lobacheva, G V; Galaktionova, G V

    1990-01-01

    Male Wistar rats, weighing on the average 200 g, were used to investigate the clinical picture of photokerato-conjunctivitis and behavioral responses to the open field test after exposing their eyes to UV-radiation with an emission maximum at 302 nm. The development threshold for conjunctivitis was 0.6 kJ/m2 and that for keratitis was 0.8 kJ/m2. The corneal lesions such as perforation and formation of persistent (up to 60 days) changes emerged beginning with the dose 3 kJ/m2 (in 50% of animals). This dose is a minimally acting dose in terms of behavior. At the dose of 10 kJ/m2 the decrease of the horizontal motor activity, which was significant from day 14, became irreversible. Thus when the organ of vision is exposed to UV-radiation, it is important to take into consideration not only structural changes but also potential functional disorders, which are associated with enhancement of inhibitory processes in the CNS. PMID:2266735

  11. IMRT may increase pneumonitis risk relative to 3D-CRT in patients receiving combined chemotherapy and radiation therapy: a modeling study of dose dumping

    PubMed Central

    Vogelius, Ivan S.; Westerly, David C.; Cannon, George M.; Mackie, Thomas R.; Mehta, Minesh P.; Sugie, Chikao; Bentzen, Søren M.

    2011-01-01

    Purpose To model the possible interaction between cytotoxic chemotherapy and radiation dose distribution with respect to the risk of radiation pneumonitis (RP). Methods and materials Eighteen non-small cell lung cancer patients previously treated with helical tomotherapy at the University of Wisconsin were selected for this modeling study. Three treatment plans were considered in the study: (1) the delivered tomotherapy plans; (2) a 3D conformal radiotherapy (3D-CRT) plan; and (3) a fixed field intensity modulated radiotherapy (IMRT) plan. The IMRT and 3D-CRT plans were generated specifically for this study. Plans were optimized without adjusting for the chemotherapy effect. The effect of chemotherapy was modeled as an independent cell killing process by considering a uniform chemotherapy equivalent radiation dose (CERD) added to all voxels of the organ at risk. Risk of radiation pneumonitis was estimated for all plans using the Lyman and the Critical Volume models. Results For radiation therapy alone, the Critical Volume model predicts that the two IMRT plans are associated with a lower risk of RP than the 3D-CRT plan. However, when the CERD exceeds a certain threshold, the RP risk after IMRT is higher than after 3D-CRT. This threshold dose is in the range estimated from clinical chemo-radiation data sets. Conclusions Cytotoxic chemotherapy may affect the relative merit of competing radiation therapy plans. More work is needed to improve our understanding of the interaction between chemotherapy and radiation dose distribution in clinical settings. PMID:21477946

  12. Increasing Radiation Therapy Dose Is Associated With Improved Survival in Patients Undergoing Stereotactic Body Radiation Therapy for Stage I Non–Small-Cell Lung Cancer

    SciTech Connect

    Koshy, Matthew; Malik, Renuka; Weichselbaum, Ralph R.; Sher, David J.

    2015-02-01

    Purpose: To determine the comparative effectiveness of different stereotactic body radiation therapy (SBRT) dosing regimens for early-stage non–small-cell lung cancer, using a large national database, focusing on the relative impact of dose as a function of tumor stage. Methods and Materials: The study included patients in the National Cancer Database from 2003 to 2006 with T1-T2N0M0 inoperable lung cancer (n=498). The biologically effective dose (BED) was calculated according to the linear quadratic formula using an α/β ratio of 10. High versus lower-dose (HD vs LD) SBRT was defined as a calculated BED above or below 150 Gy. Overall survival was estimated using Kaplan-Meier methods and Cox proportional hazard regression. Results: The 5 most common dose fractionation schemes (percentage of cohort) used were 20 Gy × 3 (34%), 12 Gy × 4 (16%), 18 Gy × 3 (10%), 15 Gy × 3 (10%), and 16 Gy × 3 (4%). The median calculated BED was 150 Gy (interquartile range 106-166 Gy). The 3-year overall survival (OS) for patients who received HD versus LD was 55% versus 46% (log–rank P=.03). On subset analysis of the T1 cohort there was no association between calculated BED and 3-year OS (61% vs 60% with HD vs LD, P=.9). Among the T2 cohort, patients receiving HD experienced superior 3-year OS (37% vs 24%, P=.01). On multivariable analysis, factors independently prognostic for mortality were female gender (hazard ratio [HR] 0.76, P=.01), T2 tumor (HR 1.99, P=.0001), and HD (HR 0.68, P=.001). Conclusions: This comparative effectiveness analysis of SBRT dose for patients with stage I non–small-cell lung cancer suggests that higher doses (>150 Gy BED) are associated with a significant survival benefit in patients with T2 tumors.

  13. A Role for the Kp Leucine Zipper in Regulating P Element Transposition in Drosophila Melanogaster

    PubMed Central

    Andrews, J. D.; Gloor, G. B.

    1995-01-01

    The KP element can repress P element mobility in Drosophila melanogaster. Three mutant KP elements were made that had either two amino acid substitutions or a single amino acid deletion in the putative leucine zipper domain found in the KP polypeptide. Each KP element was expressed from the actin 5C proximal promoter. The wild-type control construct strongly repressed P element mobility, measured by the GD sterility and sn(w) mutability assays, in a position-independent manner. The single amino acid deletion mutant failed to repress P mobility regardless of its insertion site, while repression of P element mobility by the double amino acid substitution mutants was position dependent. The results show that the leucine zipper of the KP polypeptide is important for P element regulation. This supports the multimer-poisoning model of P element repression, because leucine zipper motifs are involved in protein-protein interactions. PMID:8647395

  14. Asymmetric photolysis of /RS/-leucine with circularly polarized ultraviolet light

    NASA Technical Reports Server (NTRS)

    Flores, J. J.; Bonner, W. A.; Massey, G. A.

    1977-01-01

    (RS)-leucine in 0.1 M HCl solution has been subjected to photolysis with 212.8-nm right (R-) and left circularly polarized light (LCPL) obtained from a laser source. RCPL preferentially photolyzed the (R)-leucine component and LCPL the (S)-leucine component of the RS substrate. The enantiomeric excess produced were 1.98% for the 59% conversion with RCPL and 2.50% for the 75% conversion with LCPL. These 'equal and opposite' effects represent the second highest enantiomeric enrichments yet reported for an asymmetric photolysis and the first ever reported for a prebiotically important substrate - an amino acid. Implications regarding the origin of optical activity are briefly discussed.

  15. Intensity-Modulated Radiotherapy Might Increase Pneumonitis Risk Relative to Three-Dimensional Conformal Radiotherapy in Patients Receiving Combined Chemotherapy and Radiotherapy: A Modeling Study of Dose Dumping

    SciTech Connect

    Vogelius, Ivan S.; Westerly, David C.; Cannon, George M.; Mackie, Thomas R.; Mehta, Minesh P.; Sugie, Chikao; Bentzen, Soren M.

    2011-07-01

    Purpose: To model the possible interaction between cytotoxic chemotherapy and the radiation dose distribution with respect to the risk of radiation pneumonitis. Methods and Materials: A total of 18 non-small-cell lung cancer patients previously treated with helical tomotherapy at the University of Wisconsin were selected for the present modeling study. Three treatment plans were considered: the delivered tomotherapy plans; a three-dimensional conformal radiotherapy (3D-CRT) plan; and a fixed-field intensity-modulated radiotherapy (IMRT) plan. The IMRT and 3D-CRT plans were generated specifically for the present study. The plans were optimized without adjusting for the chemotherapy effect. The effect of chemotherapy was modeled as an independent cell killing process by considering a uniform chemotherapy equivalent radiation dose added to all voxels of the organ at risk. The risk of radiation pneumonitis was estimated for all plans using the Lyman and the critical volume models. Results: For radiotherapy alone, the critical volume model predicts that the two IMRT plans are associated with a lower risk of radiation pneumonitis than the 3D-CRT plan. However, when the chemotherapy equivalent radiation dose exceeds a certain threshold, the radiation pneumonitis risk after IMRT is greater than after 3D-CRT. This threshold dose is in the range estimated from clinical chemoradiotherapy data sets. Conclusions: Cytotoxic chemotherapy might affect the relative merit of competing radiotherapy plans. More work is needed to improve our understanding of the interaction between chemotherapy and the radiation dose distribution in clinical settings.

  16. Transport of leucine, isoleucine and valine by luminal membrane vesicles from rabbit proximal tubule.

    PubMed

    Jørgensen, K E; Kragh-Hansen, U; Sheikh, M I

    1990-03-01

    1. Transport of L- and D-isomers of leucine, isoleucine and valine by luminal membrane vesicles prepared from either the convoluted part (pars convoluta) or the straight part (pars recta) of rabbit proximal tubule was studied by a rapid filtration technique and by a spectrophotometric method using a potential-sensitive carbocyanine dye. 2. Both types of renal membrane vesicle take up the amino acids in a Na(+)-dependent, H(+)-independent and electrogenic manner. The L-isomers are transported with higher affinities than their corresponding D-forms, of which only D-leucine is taken up to a significant extent. 3. Membrane vesicles prepared from pars convoluta take up the L-amino acids by a single and common system. Filtration studies showed that the Km values for L-leucine and L-valine transport are, on average, 0.23 and 0.83 mM, respectively. The values of KA (the concentration of amino acid producing a half-maximal optical response) are comparable to those of Km, namely 0.18 mM for L-leucine and 0.60 mM for L-valine. KA for L-isoleucine transport was found to be 0.19 mM. D-Leucine is taken up by the same system but with a much lower affinity (KA = 7.2 mM). 4. Membrane vesicles prepared from pars recta possess two, and probably common, transport systems for the L-isomers of the amino acids. The average Michaelis-Menten constants were as follows: L-leucine, K1m = 0.17 mM, K2m = 6.5 mM; L-valine, K1m = 0.19 mM, K2m = 11.5 mM. The KA values were: L-leucine, K1A = 0.12 mM, K2A = 7.4 mM; L-valine, K1A = 0.18 mM, K2A = 10.0 mM; L-isoleucine, K1A = 0.17 mM, K2A = 9.0 mM. D-Leucine is taken up by a low-affinity system only (KA = 6.5 mM), which seems to be the same as the low-affinity system transporting the L-forms of the amino acids. PMID:2352186

  17. Do non-targeted effects increase or decrease low dose risk in relation to the linear-non-threshold (LNT) model?

    PubMed

    Little, M P

    2010-05-01

    In this paper we review the evidence for departure from linearity for malignant and non-malignant disease and in the light of this assess likely mechanisms, and in particular the potential role for non-targeted effects. Excess cancer risks observed in the Japanese atomic bomb survivors and in many medically and occupationally exposed groups exposed at low or moderate doses are generally statistically compatible. For most cancer sites the dose-response in these groups is compatible with linearity over the range observed. The available data on biological mechanisms do not provide general support for the idea of a low dose threshold or hormesis. This large body of evidence does not suggest, indeed is not statistically compatible with, any very large threshold in dose for cancer, or with possible hormetic effects, and there is little evidence of the sorts of non-linearity in response implied by non-DNA-targeted effects. There are also excess risks of various types of non-malignant disease in the Japanese atomic bomb survivors and in other groups. In particular, elevated risks of cardiovascular disease, respiratory disease and digestive disease are observed in the A-bomb data. In contrast with cancer, there is much less consistency in the patterns of risk between the various exposed groups; for example, radiation-associated respiratory and digestive diseases have not been seen in these other (non-A-bomb) groups. Cardiovascular risks have been seen in many exposed populations, particularly in medically exposed groups, but in contrast with cancer there is much less consistency in risk between studies: risks per unit dose in epidemiological studies vary over at least two orders of magnitude, possibly a result of confounding and effect modification by well known (but unobserved) risk factors. In the absence of a convincing mechanistic explanation of epidemiological evidence that is, at present, less than persuasive, a cause-and-effect interpretation of the reported

  18. Increasing Dose of Autologous Bone Marrow Mononuclear Cells Transplantation Is Related to Stroke Outcome: Results from a Pooled Analysis of Two Clinical Trials.

    PubMed

    Moniche, Francisco; Rosado-de-Castro, Paulo Henrique; Escudero, Irene; Zapata, Elena; de la Torre Laviana, Francisco Javier; Mendez-Otero, Rosalia; Carmona, Magdalena; Piñero, Pilar; Bustamante, Alejandro; Lebrato, Lucía; Cabezas, Juan Antonio; Gonzalez, Alejandro; de Freitas, Grabriel R; Montaner, Joan

    2016-01-01

    Background and Purpose. BM-MNC transplantation improves recovery in experimental models of ischemic stroke. Clinical trials are ongoing to test efficacy in stroke patients. However, whether cell dose is related to outcomes is not known. Methods. We performed a pooling data analysis of two pilot clinical trials with autologous BM-MNCs transplantation in ischemic stroke patients. Cell dose and route were analyzed to evaluate their relation to good outcome (m-Rankin scale [mRS] score 0-2) at 6 months. Results. Twenty-two patients were included. A median of 153 × 10(6) (±121 × 10(6)) BM-MNCs was injected. Intra-arterial route was used in 77.3% of cases. A higher number of cells injected were associated with better outcomes at 180 days (390 × 10(6) [320-422] BM-MNCs injected in those patients with mRS of 0-2 at 6 months versus 130 × 10(6) [89-210] in those patients with mRS 3-6, p = 0.015). In the intra-arterially treated patients, a strong correlation between dose of cells and disability was found (r = -0.63, p = 0.006). A cut point of 310 × 10(6) injected cells predicted good outcome with 80% sensitivity and 88.2% specificity. Conclusions. Similar to preclinical studies, a higher dose of autologous BM-MNC was related to better outcome in stroke patients, especially when more than 310 × 10(6) cells are injected. Further interventional studies are warranted to confirm these data. PMID:27525011

  19. K-Ras mutant fraction in A/J mouse lung increases as a function of benzo[a]pyrene dose

    EPA Science Inventory

    K-Ras mutant fraction (MF) was measured to examine the default assumption of low dose linearity in the benzo[a]pyrene (B[a]P) mutational response. Groups of ten male A/J mice (7-9 weeks-old) received a single i.p. injection of 0, 0.05, 0.5, 5, or 50 mg/kg B[a]P, and were sacrifi...

  20. Increasing Dose of Autologous Bone Marrow Mononuclear Cells Transplantation Is Related to Stroke Outcome: Results from a Pooled Analysis of Two Clinical Trials

    PubMed Central

    Escudero, Irene; Zapata, Elena; de la Torre Laviana, Francisco Javier; Carmona, Magdalena; Piñero, Pilar; Bustamante, Alejandro; Lebrato, Lucía; Cabezas, Juan Antonio; Gonzalez, Alejandro; de Freitas, Grabriel R.; Montaner, Joan

    2016-01-01

    Background and Purpose. BM-MNC transplantation improves recovery in experimental models of ischemic stroke. Clinical trials are ongoing to test efficacy in stroke patients. However, whether cell dose is related to outcomes is not known. Methods. We performed a pooling data analysis of two pilot clinical trials with autologous BM-MNCs transplantation in ischemic stroke patients. Cell dose and route were analyzed to evaluate their relation to good outcome (m-Rankin scale [mRS] score 0–2) at 6 months. Results. Twenty-two patients were included. A median of 153 × 106 (±121 × 106) BM-MNCs was injected. Intra-arterial route was used in 77.3% of cases. A higher number of cells injected were associated with better outcomes at 180 days (390 × 106 [320–422] BM-MNCs injected in those patients with mRS of 0–2 at 6 months versus 130 × 106 [89–210] in those patients with mRS 3–6, p = 0.015). In the intra-arterially treated patients, a strong correlation between dose of cells and disability was found (r = −0.63, p = 0.006). A cut point of 310 × 106 injected cells predicted good outcome with 80% sensitivity and 88.2% specificity. Conclusions. Similar to preclinical studies, a higher dose of autologous BM-MNC was related to better outcome in stroke patients, especially when more than 310 × 106 cells are injected. Further interventional studies are warranted to confirm these data. PMID:27525011

  1. Effect of increasing doses of beta agonists on spirometric parameters, exercise capacity, and quality of life in patients with chronic airflow limitation.

    PubMed Central

    Jaeschke, R.; Guyatt, G. H.; Willan, A.; Cook, D.; Harper, S.; Morris, J.; Ramsdale, H.; Haddon, R.; Newhouse, M.

    1994-01-01

    BACKGROUND--A study was undertaken to determine the impact of different doses of inhaled terbutaline on peak flow rates, spirometric parameters, functional exercise capacity, and quality of life in patients with chronic airflow limitation. METHODS--A double blind, randomised, placebo controlled, multiple crossover trial was conducted with treatment periods of one week. Patients with a clinical diagnosis of chronic airflow limitation and FEV1 below 70% predicted after administration of bronchodilator were recruited from secondary care respiratory practices, and the effect of 500, 1000, and 1500 micrograms inhaled terbutaline four times daily on spirometric parameters (FEV1, FVC), maximum inspiratory pressures, six minute walking distance, and health-related quality of life (Chronic Respiratory Disease Questionnaire, Quality of Well Being, Standard Gamble) was measured. RESULTS--Twenty five patients completed the trial. Peak flow rates and FEV1 showed statistically significant but clinically trivial improvement on the higher drug doses. Results of maximum inspiratory pressure measurements, walk test distance, and quality of life measures showed minimal differences on the different dosages, and none of the differences approached conventional statistical significance. CONCLUSIONS--Regular use of beta agonists in doses higher than two puffs four times a day is very unlikely to provide additional functional or symptomatic benefit to patients with chronic airflow limitation. PMID:8016770

  2. Leucine stimulates protein synthesis in skeletal muscle of neonatal pigs by enhancing mTORC1 activation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Skeletal muscle in the neonate grows at a rapid rate due in part to an enhanced sensitivity to the postprandial rise in amino acids, particularly leucine. To elucidate the molecular mechanism by which leucine stimulates protein synthesis in neonatal muscle, overnight-fasted 7-day-old piglets were tr...

  3. Involvement of protein kinase C activation in L-leucine-induced stimulation of protein synthesis in l6 myotubes.

    PubMed

    Yagasaki, Kazumi; Morisaki, Naoko; Kitahara, Yoshiro; Miura, Atsuhito; Funabiki, Ryuhei

    2003-11-01

    Effects of leucine and related compounds on protein synthesis were studied in L6 myotubes. The incorporation of [(3)H]tyrosine into cellular protein was measured as an index of protein synthesis. In leucine-depleted L6 myotubes, leucine and its keto acid, alpha-ketoisocaproic acid (KIC), stimulated protein synthesis, while D-leucine did not. Mepacrine, an inhibitor of both phospholipases A(2) and C, canceled stimulatory actions of L-leucine and KIC on protein synthesis. Neither indomethacin, an inhibitor of cyclooxygenase, nor caffeic acid, an inhibitor of lipoxygenase, diminished their stimulatory actions, suggesting no involvement of arachidonic acid metabolism. Conversely, 1-O-hexadecyl-2-O-methylglycerol, an inhibitor of proteinkinase C, significantly canceled the stimulatory actions of L-leucine and KIC on protein synthesis, suggesting an involvement of phosphatidylinositol degradation and activation of protein kinase C. L-Leucine caused a rapid activation of protein kinase C in both cytosol and membrane fractions of the cells. These results strongly suggest that both L-leucine and KIC stimulate protein synthesis in L6 myotubes through activation of phospholipase C and protein kinase C. PMID:19003213

  4. The small leucine-rich proteoglycan BGN accumulates in CADASIL and binds to NOTCH3

    PubMed Central

    Zhang, Xiaojie; Lee, Soo Jung; Young, Marian F.; Wang, Michael M.

    2015-01-01

    Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited form of cerebral small vessel disease caused by mutations in conserved residues of NOTCH3. Affected arteries of CADASIL feature fibrosis and accumulation of NOTCH3. A variety of collagen subtypes (types I, III, IV, and VI) have been identified in fibrotic CADASIL vessels. Biglycan (BGN) and decorin (DCN), are Class I members of the small leucine-rich proteoglycan (SLRP) family that regulate collagen fibril size. Because DCN has been shown to deposit in arteries in cerebral small vessel disease, we tested whether BGN accumulates in arteries of CADASIL brains. BGN was strongly expressed in both small penetrating and leptomeningeal arteries of CADASIL brain. BGN protein was localized to all three layers of arteries (intima, media, and adventitia). Substantially more immunoreactivity was observed in CADASIL brains compared to controls. Immunoblotting of brain lysates showed a 4-fold increase in CADASIL brains (compared to controls). Messenger RNA encoding BGN was also increased in CADASIL and was localized by in situ hybridization to all three vascular layers in CADASIL. Human cerebrovascular smooth muscle cells exposed to purified NOTCH3 ectodomain upregulated BGN, DCN, and COL4A1 through mechanisms that are sensitive to rapamycin, a potent mTOR inhibitor. In addition, BGN protein interacted directly with NOTCH3 protein in cell culture and in direct protein interaction assays. In conclusion, BGN is a CADASIL-enriched protein that potentially accumulates in vessels by mTOR-mediated transcriptional activation and/or post-translational accumulation via protein interactions with NOTCH3 and collagen. PMID:25578324

  5. Inhibitory Role of the Small Leucine-Rich Proteoglycan Biglycan in Bladder Cancer

    PubMed Central

    Niedworok, Christian; Röck, Katharina; Kretschmer, Inga; Freudenberger, Till; Nagy, Nadine; Szarvas, Tibor; vom Dorp, Frank; Reis, Henning; Rübben, Herbert; Fischer, Jens W.

    2013-01-01

    Background Urothelial bladder cancer is the ninth most common cancer. Despite surgical and chemotherapeutic treatment the prognosis is still poor once bladder cancer progresses to a muscle-invasive state. Discovery of new diagnostic markers and pathophysiologic effectors might help to contribute to novel diagnostic and therapeutic options. The extracellular matrix microenvironment shaped by the extracellular matrix critically affects tumor cell and stroma cell functions. Therefore, aim of the present study was to assess the possible implication of the small leucine-rich proteoglycan biglycan in progression of human urothelial bladder cancer. Methods and Results For this purpose tumor biopsies of 76 bladder cancer patients with different tumor stages (pTa, pT1-T4) were investigated with respect to biglycan expression and correlated with a long-term (10 years) clinical follow-up. Interestingly, higher biglycan mRNA expression was associated with higher tumor stages and muscle invasiveness. In vitro knock-down of endogenous biglycan in human urothelial carcinoma cells (J82 cells) increased proliferation, whereas addition of recombinant biglycan and overexpression of biglycan inhibited tumor cell proliferation. In line with this growth-inhibitory effect of biglycan, transplantation of J82 cells after knock-down of biglycan resulted in significantly increased growth of subcutaneous xenograft tumors in nude mice in vivo. Furthermore, treatment with two anti-proliferative, multi-receptor tyrosine kinase inhibitors—sunitinib and sorafenib—strongly upregulated biglycan expression. Collectively, the experimental data suggest that high biglycan expression is associated with reduced tumor cell proliferation. In accordance, Kaplan-Meier analysis revealed higher 10-year survival in patients with high biglycan mRNA expression in tumor biopsies. Conclusion In conclusion, the present data suggest that biglycan is an endogenous inhibitor of bladder cancer cell proliferation that

  6. Equilibrium transitions between side-chain conformations in leucine and isoleucine.

    PubMed

    Caballero, Diego; Smith, W Wendell; O'Hern, Corey S; Regan, Lynne

    2015-08-01

    Despite recent improvements in computational methods for protein design, we still lack a quantitative, predictive understanding of the intrinsic probabilities for amino acids to adopt particular side-chain conformations. Surprisingly, this question has remained unsettled for many years, in part because of inconsistent results from different experimental approaches. To explicitly determine the relative populations of different side-chain dihedral angles, we performed all-atom hard-sphere Langevin Dynamics simulations of leucine (Leu) and isoleucine (Ile) dipeptide mimetics with stereo-chemical constraints and repulsive-only steric interactions between non-bonded atoms. We determine the relative populations of the different χ(1) and χ(2) dihedral angle combinations as a function of the backbone dihedral angles ϕ and ψ. We also propose, and test, a mechanism for inter-conversion between the different side-chain conformations. Specifically, we discover that some of the transitions between side-chain dihedral angle combinations are very frequent, whereas others are orders of magnitude less frequent, because they require rare coordinated motions to avoid steric clashes. For example, to transition between different values of χ(2), the Leu side-chain bond angles κ(1) and κ(2) must increase, whereas to transition in χ(1), the Ile bond angles λ(1) and λ(2) must increase. These results emphasize the importance of computational approaches in stimulating further experimental studies of the conformations of side-chains in proteins. Moreover, our studies emphasize the power of simple steric models to inform our understanding of protein structure, dynamics, and design. PMID:26018846

  7. Maternal embryonic leucine zipper kinase is stabilized in mitosis by phosphorylation and is partially degraded upon mitotic exit

    SciTech Connect

    Badouel, Caroline; Chartrain, Isabelle; Blot, Joelle; Tassan, Jean-Pierre

    2010-08-01

    MELK (maternal embryonic leucine zipper kinase) is a cell cycle dependent protein kinase involved in diverse cell processes including cell proliferation, apoptosis, cell cycle and mRNA processing. Noticeably, MELK expression is increased in cancerous tissues, upon cell transformation and in mitotically-blocked cells. The question of how MELK protein level is controlled is therefore important. Here, we show that MELK protein is restricted to proliferating cells derived from either cancer or normal tissues and that MELK protein level is severely decreased concomitantly with other cell cycle proteins in cells which exit the cell cycle. Moreover, we demonstrate in human HeLa cells and Xenopus embryos that approximately half of MELK protein is degraded upon mitotic exit whereas another half remains stable during interphase. We show that the stability of MELK protein in M-phase is dependent on its phosphorylation state.

  8. Low-dose radiation from 18F-FDG PET does not increase cancer frequency or shorten latency but reduces kidney disease in cancer-prone Trp53+/- mice

    SciTech Connect

    Taylor, Kristina; Lemon, Jennifer A.; Phan, Nghi; Boreham, Douglas R.

    2014-05-28

    There is considerable interest in the health effects associated with low-level radiation exposure from medical imaging procedures. Concerns in the medical community that increased radiation exposure from imaging procedures may increase cancer risk among patients are confounded by research showing that low-dose radiation exposure can extend lifespan by increasing the latency period of some types of cancer. The most commonly used radiopharmaceutical for positron emission tomography (PET) scans is 2-[18F] fluoro-2-deoxy-d-glucose (18F-FDG), which exposes tissue to a low-dose, mixed radiation quality: 634 keV β+ and 511 keV γ-rays. The goal of this research was to investigate how modification of cancer risk associated with exposure to low-dose ionising radiation in cancer-prone Trp53+/- mice is influenced by radiation quality from PET. At 7-8 weeks of age, Trp53+/- female mice were exposed to one of five treatments: 0 Gy, 10 mGy γ-rays, 10 mGy 18F-FDG, 4 Gy γ-rays, 10 mGy 18F-FDG + 4 Gy γ-rays (n > 185 per group). The large 4-Gy radiation dose significantly reduced the lifespan by shortening the latency period of cancer and significantly increasing the number of mice with malignancies, compared with unirradiated controls. The 10 mGy γ-rays and 10 mGy PET doses did not significantly modify the frequency or latency period of cancer relative to unirradiated mice. Similarly, the PET scan administered prior to a large 4-Gy dose did not significantly modify the latency or frequency of cancer relative to mice receiving a dose of only 4 Gy. The relative biological effectiveness of radiation quality from 18F-FDG, with respect to malignancy, is approximately 1. Furthermore, when non-cancer endpoints were studied, it was found that the 10-mGy PET group had a significant reduction in kidney lesions (P < 0.021), indicating that a higher absorbed dose (20 ± 0.13 mGy), relative to the whole-body average

  9. Low-dose radiation from 18F-FDG PET does not increase cancer frequency or shorten latency but reduces kidney disease in cancer-prone Trp53+/- mice

    DOE PAGESBeta

    Taylor, Kristina; Lemon, Jennifer A.; Phan, Nghi; Boreham, Douglas R.

    2014-05-28

    There is considerable interest in the health effects associated with low-level radiation exposure from medical imaging procedures. Concerns in the medical community that increased radiation exposure from imaging procedures may increase cancer risk among patients are confounded by research showing that low-dose radiation exposure can extend lifespan by increasing the latency period of some types of cancer. The most commonly used radiopharmaceutical for positron emission tomography (PET) scans is 2-[18F] fluoro-2-deoxy-d-glucose (18F-FDG), which exposes tissue to a low-dose, mixed radiation quality: 634 keV β+ and 511 keV γ-rays. The goal of this research was to investigate how modification of cancermore » risk associated with exposure to low-dose ionising radiation in cancer-prone Trp53+/- mice is influenced by radiation quality from PET. At 7-8 weeks of age, Trp53+/- female mice were exposed to one of five treatments: 0 Gy, 10 mGy γ-rays, 10 mGy 18F-FDG, 4 Gy γ-rays, 10 mGy 18F-FDG + 4 Gy γ-rays (n > 185 per group). The large 4-Gy radiation dose significantly reduced the lifespan by shortening the latency period of cancer and significantly increasing the number of mice with malignancies, compared with unirradiated controls. The 10 mGy γ-rays and 10 mGy PET doses did not significantly modify the frequency or latency period of cancer relative to unirradiated mice. Similarly, the PET scan administered prior to a large 4-Gy dose did not significantly modify the latency or frequency of cancer relative to mice receiving a dose of only 4 Gy. The relative biological effectiveness of radiation quality from 18F-FDG, with respect to malignancy, is approximately 1. Furthermore, when non-cancer endpoints were studied, it was found that the 10-mGy PET group had a significant reduction in kidney lesions (P < 0.021), indicating that a higher absorbed dose (20 ± 0.13 mGy), relative to the whole-body average, which occurs in specific tissues, may not be detrimental.« less

  10. Fludarabine-Busulfan Reduced-Intensity Conditioning in Comparison with Fludarabine-Melphalan Is Associated with Increased Relapse Risk In Spite of Pharmacokinetic Dosing.

    PubMed

    Damlaj, Moussab; Alkhateeb, Hassan B; Hefazi, Mehrdad; Partain, Daniel K; Hashmi, Shahrukh; Gastineau, Dennis A; Al-Kali, Aref; Wolf, Robert C; Gangat, Naseema; Litzow, Mark R; Hogan, William J; Patnaik, Mrinal M

    2016-08-01

    Fludarabine with busulfan (FB) and fludarabine with melphalan (FM) are commonly used reduced-intensity conditioning (RIC) regimens. Pharmacokinetic dosing of busulfan (Bu) is frequently done for myeloablative conditioning, but evidence for its use is limited in RIC transplants. We compared transplant outcomes of FB versus FM using i.v. Bu targeted to the area under the curve (AUC). A total of 134 RIC transplants (47 FB and 87 FM) for acute myelogenous leukemia and myelodysplastic syndrome were identified, and median follow-up of the cohort was 40 months (range, 0 to 63.3). A significantly higher 2-year cumulative incidence of relapse (CIR) was associated with FB versus FM at 35.6% versus 17.3%, respectively (P = .0058). Furthermore, 2-year progression-free survival rates were higher for FM versus FB at 60.5% versus 48.7%, respectively (P = .04). However, 2-year rates of nonrelapse mortality (NRM) and overall survival (OS) were similar. The need for dose adjustment based on AUC did not alter relapse risk or NRM. Patients with Karnofsky performance status ≥ 90 who received FM had a 2-year OS rate of 74.8% versus 48.3% for FB (P = .03). FB use remained prognostic for relapse in multivariable analysis (hazard ratio, 2.75; 95% confidence interval, 1.28 to 5.89; P = .0097). In summary, in spite of AUC-directed dosing, FB compared with FM was associated with a significantly higher CIR. PMID:27164061

  11. Dietary protein reduction in sheep and goats: different effects on L-alanine and L-leucine transport across the brush-border membrane of jejunal enterocytes.

    PubMed

    Schröder, B; Schöneberger, M; Rodehutscord, M; Pfeffer, E; Breves, G

    2003-08-01

    It was the aim of this study to examine the potential regulatory effects of a long-term low dietary protein supply on the transport capacity of the jejunal brush-border membrane for amino acids. For this purpose, we used the neutral amino acids L-alanine (representative for nonessential amino acids) and L-leucine (representative for essential amino acids) as model substances. Ten sheep lambs, 8 weeks of age and 19-27 kg body weight, were allotted to two dietary regimes with either adequate or reduced protein supply which was achieved by 17.9% and 9.7% of crude protein in the concentrated feed, respectively. The feeding periods were 4-6 weeks in length. Similarly, eight goat kids of 5-7 weeks of age and 8-14 kg body weight were allotted to either adequate (crude protein 20.1%, feeding period 9-12 weeks) or reduced protein supply (10.1%, feeding period 17-18 weeks). Dietary protein reduction in lambs caused a significant body weight loss of 0.6 +/- 0.7 kg, whereas the body weight in control animals increased by 1.9 +/- 0.7 kg (P<0.05). Plasma urea concentrations decreased significantly by 60% (low protein 2.3 +/- 0.1 versus control 5.7 +/- 0.2 mmol l(-1), P<0.001). In kids, reduction of dietary protein intake led to significant decreases of the daily weight gain by 48% from 181 +/- 8 g to 94 +/- 3 g (P<0.001) and daily dry matter intake by 27% from 568 +/- 13 g to 417 +/- 6 g (P<0.01). Respective urea concentrations in plasma were reduced by 77% from 5.2 +/- 0.4 to 1.2 +/- 0.2 mmol l(-1) (P<0.01). Kinetic analyses of the initial rates of alanine uptake into isolated jejunal brush-border membrane vesicles from sheep and goats as affected by low dietary protein supply yielded that the apparent Km was neither significantly different between the species nor significantly affected by the feeding regime thus ranging between 0.12 and 0.16 mmol.l(-1). Reduction of dietary protein, however, resulted in significantly decreased Vmax values of the transport system by 25

  12. Decarboxylation of [1-(13)C]leucine by hydroxyl radicals.

    PubMed

    Guitton, J; Tinardon, F; Lamrini, R; Lacan, P; Desage, M; Francina, A

    1998-08-01

    The decarboxylation of [1-13C]leucine by hydroxyl radicals was studied by using gas chromatography-isotope ratio mass spectrometry (GC-IRMS) to follow the production of 13CO2. A Fenton reaction between a (Fe2+)-porphyrin and hydrogen peroxide under aerobic conditions yielded hydroxyl radicals. The decarboxylation rates (VLeu) measured by GC-IRMS were dependent on [1-13C]leucine, porphyrin and hydrogen peroxide concentrations. The 13CO2 production was also dependent on bicarbonate or carbon dioxide added in the reaction medium. Bicarbonate facilitated 13CO2 production, whereas carbon dioxide decreased 13CO2 production. Proton effects on some decarboxylation intermediates could explain bicarbonate or carbon dioxide effects. No effect on the decarboxylation rates was observed in the presence of the classical hydroxyl radicals scavengers dimethyl sulfoxide, mannitol, and uric acid. By contrast, a competitive effect with a strong decrease of the decarboxylation rates was observed in the presence of various amino acids: unlabeled leucine, valine, phenylalanine, cysteine, lysine, and histidine. Two reaction products, methyl-4 oxo-2 pentanoate and methyl-3 butanoate were identified by gas chromatography-mass spectrometry in comparison with standards. The present results suggest that [1-13C]leucine can participate to the coordination sphere of (Fe2+)-porphyrin, with a caged process of the hydroxyl radicals which cannot get out of the coordination sphere. PMID:9680180

  13. Autophagy and leucine promote chronological longevity and respiration proficiency during calorie restriction in yeast

    PubMed Central

    Aris, John P.; Alvers, Ashley L.; Ferraiuolo, Roy A.; Fishwick, Laura K.; Hanvivatpong, Amanda; Hu, Doreen; Kirlew, Christine; Leonard, Michael T.; Losin, Kyle J.; Marraffini, Michelle; Seo, Arnold Y.; Swanberg, Veronica; Westcott, Jennifer L.; Wood, Michael S.; Leeuwenburgh, Christiaan; Dunn, William A.

    2013-01-01

    We have previously shown that autophagy is required for chronological longevity in the budding yeast Saccharomyces cerevisiae. Here we examine the requirements for autophagy during extension of chronological life span (CLS) by calorie restriction (CR). We find that autophagy is upregulated by two CR interventions that extend CLS: water wash CR and low glucose CR. Autophagy is required for full extension of CLS during water wash CR under all growth conditions tested. In contrast, autophagy was not uniformly required for full extension of CLS during low glucose CR, depending on the atg allele and strain genetic background. Leucine status influenced CLS during CR. Eliminating the leucine requirement in yeast strains or adding supplemental leucine to growth media extended CLS during CR. In addition, we observed that both water wash and low glucose CR promote mitochondrial respiration proficiency during aging of autophagy-deficient yeast. In general, the extension of CLS by water wash or low glucose CR was inversely related to respiration deficiency in autophagy-deficient cells. Also, autophagy is required for full extension of CLS under non-CR conditions in buffered media, suggesting that extension of CLS during CR is not solely due to reduced medium acidity. Thus, our findings show that autophagy is: (1) induced by CR, (2) required for full extension of CLS by CR in most cases (depending on atg allele, strain, and leucine availability) and, (3) promotes mitochondrial respiration proficiency during aging under CR conditions. PMID:23337777

  14. 'Zipbody' leucine zipper-fused Fab in E. coli in vitro and in vivo expression systems.

    PubMed

    Ojima-Kato, Teruyo; Fukui, Kansuke; Yamamoto, Hiroaki; Hashimura, Dai; Miyake, Shiro; Hirakawa, Yuki; Yamasaki, Tomomi; Kojima, Takaaki; Nakano, Hideo

    2016-04-01

    A small antibody fragment, fragment of antigen binding (Fab), is favorable for various immunological assays. However, production efficiency of active Fab in microorganisms depends considerably on the clones. In this study, leucine zipper-peptide pairs that dimerize in parallel (ACID-p1 (LZA)/BASE-p1 (LZB) or c-Jun/c-Fos) were fused to the C-terminus of heavy chain (Hc, VH-CH1) and light chain (Lc, VL-CL), respectively, to accelerate the association of Hc and Lc to form Fab in Escherichia coli in vivo and in vitro expression systems. The leucine zipper-fused Fab named 'Zipbody' was constructed using anti-E. coli O157 monoclonal antibody obtained from mouse hybridoma and produced in both in vitro and in vivo expression systems in an active form, whereas Fab without the leucine zipper fusion was not. Similarly, Zipbody of rabbit monoclonal antibody produced in in vitro expression showed significant activity. The purified, mouse Zipbody produced in the E. coli strain Shuffle T7 Express had specificity toward the antigen; in bio-layer interferometry analysis, the KD value was measured to be 1.5-2.0 × 10(-8) M. These results indicate that leucine zipper fusion to Fab C-termini markedly enhances active Fab formation in E. coli. PMID:26902097

  15. 3D Printing of Protein Models in an Undergraduate Laboratory: Leucine Zippers

    ERIC Educational Resources Information Center

    Meyer, Scott C.

    2015-01-01

    An upper-division undergraduate laboratory experiment is described that explores the structure/function relationship of protein domains, namely leucine zippers, through a molecular graphics computer program and physical models fabricated by 3D printing. By generating solvent accessible surfaces and color-coding hydrophobic, basic, and acidic amino…

  16. Two Di-Leucine Motifs Regulate Trafficking of Mucolipin-1 to Lysosomes

    PubMed Central

    Vergarajauregui, Silvia; Puertollano, Rosa

    2006-01-01

    Mutations in the mucolipin-1 gene have been linked to mucolipidosis type IV, a lysosomal storage disorder characterized by severe neurological and ophthalmologic abnormalities. Mucolipin-1 is a membrane protein containing six putative transmembrane domains with both its N- and C-termini localized facing the cytosol. To gain information on the sorting motifs that mediate the trafficking of this protein to lysosomes, we have generated chimeras in which the N- and C- terminal tail portions of mucolipin-1 were fused to a reporter gene. In this article, we report the identification of two separate di-leucine-type motifs that co-operate to regulate the transport of mucolipin-1 to lysosomes. One di-leucine motif is positioned at the N-terminal cytosolic tail and mediates direct transport to lysosomes, whereas the other di-leucine motif is found at the C-terminal tail and functions as an adaptor protein 2-dependent internalization motif. We have also found that the C-terminal tail of mucolipin-1 is palmitoylated and that this modification might regulate the efficiency of endocytosis. Finally, the mutagenesis of both di-leucine motifs abrogated lysosomal accumulation and resulted in cell-surface redistribution of mucolipin-1. Taken together, these results reveal novel information regarding the motifs that regulate mucolipin-1 trafficking and suggest a role for palmitoylation in protein sorting. PMID:16497227

  17. Prolonged leucine infusion differentially affects tissue protein synthesis in neonatal pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leucine (Leu) acutely stimulates protein synthesis by activating the mammalian target of rapamycin complex 1 (mTORC1) pathway. To determine whether Leu can stimulate protein synthesis in muscles of different fiber types and visceral tissues of the neonate for a prolonged period and to determine the ...

  18. Role of glucocorticoid-induced leucine zipper (GILZ) in bone acquisition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glucocorticoids (GCs) have both anabolic and catabolic effects on bone. However, no GC anabolic effect mediator has been identified to date. In this report, we provide the first evidence that glucocorticoid-induced leucine zipper (GILZ), a GC anti-inflammatory effect mediator, can enhance bone forma...

  19. Identification and mapping of nucleotide binding site-leucine rich repeat resistance gene analogs in bermudagrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirty-one bermudagrass (Cynodon spp.) disease resistance gene homologs (BRGH) were cloned and sequenced from diploid, triploid, and hexaploid bermudagrass using degenerate primers to target the nucleotide binding site (NBS) of the NBS- leucine rich repeat (LRR) resistance gene family. Alignment of ...

  20. Impact of prolonged leucine supplementation on protein synthesis and lean growth in neonatal pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most low-birth weight infants experience extrauterine growth failure due to reduced nutrient intake as a result of feeding intolerance. The objective of this study was to determine whether prolonged enteral leucine supplementation improves lean growth in neonatal pigs fed a restricted protein diet. ...

  1. Selective single crystal complexation of L- or D-leucine by p-sulfonatocalix[6]arene.

    PubMed

    Atwood, Jerry L; Dalgarno, Scott J; Hardie, Michaele J; Raston, Colin L

    2005-01-21

    p-Sulfonatocalix[6]arene, organised in the 'double cone' conformation, has multi-guest capability binding either L- or D-leucine in a single crystal in a bi-layer type arrangement from a racemic mixture of the amino acid. PMID:15645029

  2. FLCN Maintains the Leucine Level in Lysosome to Stimulate mTORC1

    PubMed Central

    Chen, Zhi; Ji, Xin; Qiao, Xianfeng; Jin, Yaping; Liu, Wei

    2016-01-01

    The intracellular amino acid pool within lysosome is a signal that stimulates the nutrient-sensing mTORC1 signalling pathway. The signal transduction cascade has garnered much attention, but little is known about the sequestration of the signalling molecules within the lysosome. Using human HEK293 cells as a model, we found that suppression of the BHD syndrome gene FLCN reduced the leucine level in lysosome, which correlated with decreased mTORC1 activity. Both consequences could be reversed by supplementation with high levels of leucine, but not other tested amino acids. Conversely, overexpressed FLCN could sequester lysosomal leucine and stimulate mTORC1 in an amino acid limitation environment. These results identify a novel function of FLCN: it controls mTORC1 by modulating the leucine signal in lysosome. Furthermore, we provided evidence that FLCN exerted this role by inhibiting the accumulation of the amino acid transporter PAT1 on the lysosome surface, thereby maintaining the signal level within the organelle. PMID:27280402

  3. Leucine pulses enhance skeletal muscle protein synthesis during continuous feeding in neonatal pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infants unable to maintain oral feeding can be nourished by orogastric tube. We have shown that orogastric continuous feeding restricts muscle protein synthesis compared with intermittent bolus feeding in neonatal pigs. To determine whether leucine leu infusion can be used to enhance protein synthes...

  4. Prolonged stimulation of muscle protein synthesis by leucine in neonates is dependent on amino acid availability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rise in amino acids and insulin after a meal independently stimulate protein synthesis in skeletal muscle of neonates by activating the intracellular signalling pathways that regulate mRNA translation. Leucine, in particular, is important in mediating the response to amino acids. Previously, w...

  5. FLCN Maintains the Leucine Level in Lysosome to Stimulate mTORC1.

    PubMed

    Wu, Xiaochun; Zhao, Lingling; Chen, Zhi; Ji, Xin; Qiao, Xianfeng; Jin, Yaping; Liu, Wei

    2016-01-01

    The intracellular amino acid pool within lysosome is a signal that stimulates the nutrient-sensing mTORC1 signalling pathway. The signal transduction cascade has garnered much attention, but little is known about the sequestration of the signalling molecules within the lysosome. Using human HEK293 cells as a model, we found that suppression of the BHD syndrome gene FLCN reduced the leucine level in lysosome, which correlated with decreased mTORC1 activity. Both consequences could be reversed by supplementation with high levels of leucine, but not other tested amino acids. Conversely, overexpressed FLCN could sequester lysosomal leucine and stimulate mTORC1 in an amino acid limitation environment. These results identify a novel function of FLCN: it controls mTORC1 by modulating the leucine signal in lysosome. Furthermore, we provided evidence that FLCN exerted this role by inhibiting the accumulation of the amino acid transporter PAT1 on the lysosome surface, thereby maintaining the signal level within the organelle. PMID:27280402

  6. Crystal Structure of a Super Leucine Zipper an Extended Two-Stranded Super Long Coiled Coil

    SciTech Connect

    J Diao

    2011-12-31

    Coiled coil is a ubiquitous structural motif in proteins, with two to seven alpha helices coiled together like the strands of a rope, and coiled coil folding and assembly is not completely understood. A GCN4 leucine zipper mutant with four mutations of K3A, D7A, Y17W, and H18N has been designed, and the crystal structure has been determined at 1.6 {angstrom} resolution. The peptide monomer shows a helix trunk with short curved N- and C-termini. In the crystal, two monomers cross in 35{sup o} and form an X-shaped dimer, and each X-shaped dimer is welded into the next one through sticky hydrophobic ends, thus forming an extended two-stranded, parallel, super long coiled coil rather than a discrete, two-helix coiled coil of the wild-type GCN4 leucine zipper. Leucine residues appear at every seventh position in the super long coiled coil, suggesting that it is an extended super leucine zipper. Compared to the wild-type leucine zipper, the N-terminus of the mutant has a dramatic conformational change and the C-terminus has one more residue Glu 32 determined. The mutant X-shaped dimer has a large crossing angle of 35{sup o} instead of 18{sup o} in the wild-type dimer. The results show a novel assembly mode and oligomeric state of coiled coil, and demonstrate that mutations may affect folding and assembly of the overall coiled coil. Analysis of the formation mechanism of the super long coiled coil may help understand and design self-assembling protein fibers.

  7. Glycine restores the anabolic response to leucine in a mouse model of acute inflammation.

    PubMed

    Ham, Daniel J; Caldow, Marissa K; Chhen, Victoria; Chee, Annabel; Wang, Xuemin; Proud, Christopher G; Lynch, Gordon S; Koopman, René

    2016-06-01

    Amino acids, especially leucine, potently stimulate protein synthesis and reduce protein breakdown in healthy skeletal muscle and as a result have received considerable attention as potential treatments for muscle wasting. However, the normal anabolic response to amino acids is impaired during muscle-wasting conditions. Although the exact mechanisms of this anabolic resistance are unclear, inflammation and ROS are believed to play a central role. The nonessential amino acid glycine has anti-inflammatory and antioxidant properties and preserves muscle mass in calorie-restricted and tumor-bearing mice. We hypothesized that glycine would restore the normal muscle anabolic response to amino acids under inflammatory conditions. Relative rates of basal and leucine-stimulated protein synthesis were measured using SUnSET methodology 4 h after an injection of 1 mg/kg lipopolysaccharide (LPS). Whereas leucine failed to stimulate muscle protein synthesis in LPS-treated mice pretreated with l-alanine (isonitrogenous control), leucine robustly stimulated protein synthesis (+51%) in mice pretreated with 1 g/kg glycine. The improvement in leucine-stimulated protein synthesis was accompanied by a higher phosphorylation status of mTOR, S6, and 4E-BP1 compared with l-alanine-treated controls. Despite its known anti-inflammatory action in inflammatory cells, glycine did not alter the skeletal muscle inflammatory response to LPS in vivo or in vitro but markedly reduced DHE staining intensity, a marker of oxidative stress, in muscle cross-sections and attenuated LPS-induced wasting in C2C12 myotubes. Our observations in male C57BL/6 mice suggest that glycine may represent a promising nutritional intervention for the attenuation of skeletal muscle wasting. PMID:27094036

  8. Leucine restores murine hepatic triglyceride accumulation induced by a low-protein diet by suppressing autophagy and excessive endoplasmic reticulum stress.

    PubMed

    Yokota, Shin-Ichi; Ando, Midori; Aoyama, Shinya; Nakamura, Kawai; Shibata, Shigenobu

    2016-04-01

    Although it is known that a low-protein diet induces hepatic triglyceride (TG) accumulation in both rodents and humans, little is known about the underlying mechanism. In the present study, we modeled hepatic TG accumulation by inducing dietary protein deficiency in mice and aimed to determine whether certain amino acids could prevent low-protein diet-induced TG accumulation in the mouse liver. Mice fed a diet consisting of 3 % casein (3C diet) for 7 days showed hepatic TG accumulation with up-regulation of TG synthesis for the Acc gene and down-regulation of TG-rich lipoprotein secretion from hepatocytes for Mttp genes. Supplementing the 3 % casein diet with essential amino acids, branched-chain amino acids, or the single amino acid leucine rescued hepatic TG accumulation. In the livers of mice fed the 3 % casein diet, we observed a decrease in the levels of the autophagy substrate p62, an increase in the expression levels of the autophagy marker LC3-II, and an increase in the splicing of the endoplasmic reticulum (ER) stress-dependent Xbp1 gene. Leucine supplementation to the 3 % casein diet did not affect genes related to lipid metabolism, but inhibited the decrease in p62, the increase in LC3-II, and the increase in Xbp1 splicing levels in the liver. Our results suggest that ER stress responses and activated autophagy play critical roles in low-protein diet-induced hepatic TG accumulation in mice, and that leucine suppresses these two major protein degradation systems. This study contributes to understanding the mechanisms of hepatic disorders of lipid metabolism. PMID:26707165

  9. Light aerobic physical exercise in combination with leucine and/or glutamine-rich diet can improve the body composition and muscle protein metabolism in young tumor-bearing rats.

    PubMed

    Salomão, Emilianne Miguel; Gomes-Marcondes, Maria Cristina Cintra

    2012-12-01

    Nutritional supplementation with some amino acids may influence host's responses and also certain mechanism involved in tumor progression. It is known that exercise influences body weight and muscle composition. Previous findings from our group have shown that leucine has beneficial effects on protein composition in cachectic rat model as the Walker 256 tumor. The main purpose of this study was to analyze the effects of light exercise and leucine and/or glutamine-rich diet in body composition and skeletal muscle protein synthesis and degradation in young tumor-bearing rats. Walker tumor-bearing rats were subjected to light aerobic exercise (swimming 30 min/day) and fed a leucine-rich (3%) and/or glutamine-rich (4%) diet for 10 days and compared to healthy young rats. The carcasses were analyzed as total water and fat body content and lean body mass. The gastrocnemious muscles were isolated and used for determination of total protein synthesis and degradation. The chemical body composition changed with tumor growth, increasing body water and reducing body fat content and total body nitrogen. After tumor growth, the muscle protein metabolism was impaired, showing that the muscle protein synthesis was also reduced and the protein degradation process was increased in the gastrocnemius muscle of exercised rats. Although short-term exercise (10 days) alone did not produce beneficial effects that would reduce tumor damage, host protein metabolism was improved when exercise was combined with a leucine-rich diet. Only total carcass nitrogen and protein were recovered by a glutamine-rich diet. Exercise, in combination with an amino acid-rich diet, in particular, leucine, had effects beyond reducing tumoral weight such as improving protein turnover and carcass nitrogen content in the tumor-bearing host. PMID:22460363

  10. Leucine-rich repeat kinase 2 interacts with p21-activated kinase 6 to control neurite complexity in mammalian brain.

    PubMed

    Civiero, Laura; Cirnaru, Maria Daniela; Beilina, Alexandra; Rodella, Umberto; Russo, Isabella; Belluzzi, Elisa; Lobbestael, Evy; Reyniers, Lauran; Hondhamuni, Geshanthi; Lewis, Patrick A; Van den Haute, Chris; Baekelandt, Veerle; Bandopadhyay, Rina; Bubacco, Luigi; Piccoli, Giovanni; Cookson, Mark R; Taymans, Jean-Marc; Greggio, Elisa

    2015-12-01

    Leucine-rich repeat kinase 2 (LRRK2) is a causative gene for Parkinson's disease, but the physiological function and the mechanism(s) by which the cellular activity of LRRK2 is regulated are poorly understood. Here, we identified p21-activated kinase 6 (PAK6) as a novel interactor of the GTPase/ROC domain of LRRK2. p21-activated kinases are serine-threonine kinases that serve as targets for the small GTP binding proteins Cdc42 and Rac1 and have been implicated in different morphogenetic processes through remodeling of the actin cytoskeleton such as synapse formation and neuritogenesis. Using an in vivo neuromorphology assay, we show that PAK6 is a positive regulator of neurite outgrowth and that LRRK2 is required for this function. Analyses of post-mortem brain tissue from idiopathic and LRRK2 G2019S carriers reveal an increase in PAK6 activation state, whereas knock-out LRRK2 mice display reduced PAK6 activation and phosphorylation of PAK6 substrates. Taken together, these results support a critical role of LRRK2 GTPase domain in cytoskeletal dynamics in vivo through the novel interactor PAK6, and provide a valuable platform to unravel the mechanism underlying LRRK2-mediated pathophysiology. We propose p21-activated kinase 6 (PAK6) as a novel interactor of leucine-rich repeat kinase 2 (LRRK2), a kinase involved in Parkinson's disease (PD). In health, PAK6 regulates neurite complexity in the brain and LRRK2 is required for its function, (a) whereas PAK6 is aberrantly activated in LRRK2-linked PD brain (b) suggesting that LRRK2 toxicity is mediated by PAK6. PMID:26375402

  11. Leucine-responsive regulatory protein Lrp and PapI homologues influence phase variation of CS31A fimbriae.

    PubMed

    Graveline, Richard; Garneau, Philippe; Martin, Christine; Mourez, Michaël; Hancock, Mark A; Lavoie, Rémi; Harel, Josée

    2014-08-15

    CS31A, a K88-related surface antigen specified by the clp operon, is a member of the type P family of adhesive factors and plays a key role in the establishment of disease caused by septicemic and enterotoxigenic Escherichia coli strains. Its expression is under the control of methylation-dependent transcriptional regulation, for which the leucine-responsive regulatory protein (Lrp) is essential. CS31A is preferentially in the OFF state and exhibits distinct regulatory features compared to the regulation of other P family members. In the present study, surface plasmon resonance and DNase I protection assays showed that Lrp binds to the distal moiety of the clp regulatory region with low micromolar affinity compared to its binding to the proximal moiety, which exhibits stronger, nanomolar affinity. The complex formation was also influenced by the addition of PapI or FooI, which increased the affinity of Lrp for the clp distal and proximal regions and was required to induce phase variation. The influence of PapI or FooI, however, was predominantly associated with a more complete shutdown of clp expression, in contrast to what has previously been observed with AfaF (a PapI ortholog). Taken together, these results suggest that the preferential OFF state observed in CS31A cells is mainly due to the weak interaction of the leucine-responsive regulatory protein with the clp distal region and that the PapI homolog favors the OFF phase. Within the large repertoire of fimbrial variants in the P family, our study illustrates that having a fimbrial operon that lacks its own PapI ortholog allows it to be more flexibly regulated by other orthologs in the cell. PMID:24914179

  12. Measures against increased environmental radiation dose by the TEPCO Fukushima Dai-ichi NPP accident in some local governments in the Tokyo metropolitan area: focusing on examples of both Kashiwa and Nagareyama cities in Chiba prefecture.

    PubMed

    Iimoto, T; Fujii, H; Oda, S; Nakamura, T; Hayashi, R; Kuroda, R; Furusawa, M; Umekage, T; Ohkubo, Y

    2012-11-01

    The accident of the Fukushima Dai-ichi nuclear power plant of Tokyo Electric Power Cooperation (TEPCO) after the great east Japan earthquake (11 March 2011) elevated the background level of environmental radiation in Eastern Japan. Around the Tokyo metropolitan area, especially around Kashiwa and Nagareyama cities, the ambient dose equivalent rate has been significantly increased after the accident. Responding to strong requests from citizens, the local governments started to monitor the ambient dose equivalent rate precisely and officially, about 3 months after the accident had occurred. The two cities in cooperation with each other also organised a local forum supported by three radiation specialists. In this article, the activities of the local governments are introduced, with main focus on radiation monitoring and measurements. Topics are standardisation of environmental radiation measurements for ambient dose rate, dose mapping activity, investigation of foodstuff and drinking water, lending survey meters to citizens, etc. Based on the data and facts mainly gained by radiation monitoring, risk management and relating activity have been organised. 'Small consultation meetings in kindergartens', 'health consultation service for citizens', 'education meeting on radiation protection for teachers, medical staffs, local government staffs, and leaders of active volunteer parties' and 'decontamination activity', etc. are present key activities of the risk management and restoration around the Tokyo metropolitan area. PMID:22927655

  13. BAY 50-4798, a novel, high-affinity receptor-specific recombinant interleukin-2 analog, induces dose-dependent increases in CD25 expression and proliferation among unstimulated, human peripheral blood mononuclear cells in vitro.

    PubMed

    Matthews, Lynn; Chapman, Sherita; Ramchandani, Meena S; Lane, H Clifford; Davey, Richard T; Sereti, Irini

    2004-12-01

    Interleukin-2 administration induces CD4 T cell expansion in HIV-infected patients, however, toxicity can limit dosing. BAY 50-4798 is a recombinant IL-2 analog with >1000-fold specificity for the high-affinity IL-2 receptor. The effects of this compound on unstimulated human PBMC were evaluated. PBMC from HIV(-) and HIV(+) donors were cultured in vitro with incremental doses of BAY 50-4798 or aldesleukin. CD25 expression and proliferation were evaluated with flow cytometry. Cytokine levels were measured by ELISA in culture supernatants. BAY 50-4798 induced dose-dependent increases in CD25 expression and proliferation of T cells, NK, and B cells and showed selectivity for CD4 T cells expressing CD25. Induction of pro-inflammatory cytokines was also dose-dependent and was observed at the concentrations of BAY 50-4798 with the highest biologic activity. These data suggest that BAY 50-4798 can induce proliferation of unstimulated T cells but loss of T cell selectivity and induction of pro-inflammatory cytokines occur at concentrations exerting the highest biologic activity. PMID:15507389

  14. Increase in Bacterial Colony Formation from a Permafrost Ice Wedge Dosed with a Tomitella biformata Recombinant Resuscitation-Promoting Factor Protein.

    PubMed

    Puspita, Indun Dewi; Kitagawa, Wataru; Kamagata, Yoichi; Tanaka, Michiko; Nakatsu, Cindy H

    2015-01-01

    Resuscitation-promoting factor (Rpf) is a protein that has been found in a number of different Actinobacteria species and has been shown to promote the growth of active cells and resuscitate dormant (non-dividing) cells. We previously reported the biological activity of an Rpf protein in Tomitella biformata AHU 1821(T), an Actinobacteria isolated from a permafrost ice wedge. This protein is excreted outside the cell; however, few studies have investigated its contribution in environmental samples to the growth or resuscitation of bacteria other than the original host. Therefore, the aim of the present study was to determine whether Rpf from T. biformata impacted the cultivation of other bacteria from the permafrost ice wedge from which it was originally isolated. All experiments used recombinant Rpf proteins produced using a Rhodococcus erythropolis expression system. Dilutions of melted surface sterilized ice wedge samples mixed with different doses of the purified recombinant Rpf (rRpf) protein indicated that the highest concentration tested, 1250 pM, had a significantly (p <0.05) higher number of CFUs on agar plates after 8 d, approximately 14-fold higher than that on control plates without rRpf. 16S rRNA gene sequences revealed that all the colonies on plates were mainly related to Brevibacterium antiquum strain VKM Ac-2118 (AY243344), with 98-99% sequence identity. This species is also a member of the phylum Actinobacteria and was originally isolated from Siberian permafrost sediments. The results of the present study demonstrated that rRpf not only promoted the growth of T. biformata from which it was isolated, but also enhanced colony formation by another Actinobacteria in an environmental sample. PMID:25843055

  15. Leucine and protein metabolism in obese zucker rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Branched-chain amino acids (BCAAs) are circulating nutrient signals for protein accretion, however they increase in obesity and appear to prognosticate diabetes onset. To understand the mechanisms whereby obesity affects BCAAs and protein metabolism, we employed metabolomics and measured rates of [1...

  16. Dimerization mediated through a leucine zipper activates the oncogenic potential of the met receptor tyrosine kinase.

    PubMed Central

    Rodrigues, G A; Park, M

    1993-01-01

    Oncogenic activation of the met (hepatocyte growth factor/scatter factor) receptor tyrosine kinase involves a genomic rearrangement that generates a hybrid protein containing tpr-encoded sequences at its amino terminus fused directly to the met-encoded receptor kinase domain. Deletion of Tpr sequences abolishes the transforming ability of this protein, implicating this region in oncogenic activation. We demonstrate, by site-directed mutagenesis and coimmunoprecipitation experiments, that a leucine zipper motif within Tpr mediates dimerization of the tpr-met product and is essential for the transforming activity of the met oncogene. By analogy with ligand-stimulated activation of receptor tyrosine kinases, we propose that constitutive dimerization mediated by a leucine zipper motif within Tpr is responsible for oncogenic activation of the Met kinase. The possibility that this mechanism of activation represents a paradigm for a class of receptor tyrosine kinase oncogenes activated by DNA rearrangement is discussed. Images PMID:8413267

  17. Anatomical localization of leucine-rich repeat kinase 2 in mouse brain.

    PubMed

    Melrose, H; Lincoln, S; Tyndall, G; Dickson, D; Farrer, M

    2006-01-01

    Mutations in leucine-rich repeat kinase 2 (LRRK2) have recently been identified in autosomal dominant late-onset Parkinson's disease. Expression of LRRK2 has previously been reported in brain; however, no precise anatomical information is yet available. We have performed in situ hybridization and quantitative reverse transcription polymerase chain reaction to map LRRK2 mRNA expression in mouse brain. We find LRRK2 is highly expressed in the striatum, cortex and olfactory tubercle; however, little or no expression is found in the substantia nigra, where dopaminergic neurons preferentially degenerate in Parkinson's disease. These findings suggest that LRRK2 mRNA is expressed in dopamine-receptive areas rather than in the dopamine-synthesizing neurons. Consistent with a role LRRK2 in Parkinson's disease, dysfunction of leucine-rich repeat kinase 2 protein in dopamine-innervated areas may to lead to altered dopaminergic neurotransmission and degeneration of the nigro-striatal pathway. PMID:16504409

  18. Papain-Catalyzed Chemoenzymatic Synthesis of Telechelic Polypeptides Using Bis(Leucine Ethyl Ester) Initiator.

    PubMed

    Tsuchiya, Kousuke; Numata, Keiji

    2016-07-01

    In order to construct unique polypeptide architectures, a novel telechelic-type initiator with two leucine ethyl ester units is designed for chemoenzymatic polymerization. Glycine or alanine ethyl ester is chemoenzymatically polymerized using papain in the presence of the initiator, and the propagation occurs at each leucine ethyl ester unit to produce the telechelic polypeptide. The formation of the telechelic polypeptides is confirmed by (1) H NMR and MALDI-TOF mass spectroscopies. It is revealed by AFM observation that long nanofibrils are formed from the telechelic polyalanine, whereas a conventional linear polyalanine with a similar degree of polymerization shows granule-like structures. The telechelic polyglycine and polyalanine show the crystalline structures of Polyglycine II and antiparallel β-sheet, respectively. It is demonstrated that this method to synthesize telechelic-type polypeptides potentially opens up a pathway to construct novel hierarchical structures by self-assembly. PMID:26947148

  19. The radiolysis of tryptophan and leucine with P-32 beta-radiation

    NASA Technical Reports Server (NTRS)

    Blair, N. E.; Bonner, W. A.

    1980-01-01

    The paper extends earlier experiments on the radiolysis of DL-tryptophan using P-32 beta-radiation to longer reaction times, observing complete destruction of tryptophan by secondary, nonradiolytic processes. In addition DL-leucine is irradiated with P-32 beta-irradiation at -196 C, leading to radiolyses to the extents of about 20-30%, but observing no concomitant asymmetric bias. The complete absence of asymmetric bias in the present and earlier (Bonner et al., 1979) radiolyses of aqueous tryptophan at -25 C and the present radiolyses of water-free leucine at -196 C using P-32 beta-radiation and its accompanying bremsstrahlung leave it an open question whether or not the Vester-Ulbricht beta-decay/bremsstrahlung mechanism for the origin of optical activity is a viable one.

  20. Chronic ethanol (EtOH) feeding increases muscarinic receptor (mAChR) density in esophagus without parallel change in dose response (D-R) to cholinergic agonists

    SciTech Connect

    Keshavarzian, A.; Gordon, J.H.; Urban, G.; Fields, J.Z. VA Hospital, Hines, IL )

    1991-03-11

    The mAChR/effector pathway for signal transduction is important in the physiology of esophagus and mAChR alterations are involved in EtOH induced changes in several organs. To see if EtOH-induced increases in lower esophageal sphincter pressure (LESP) are due to upregulation of mAChR, the authors evaluated mAChR binding and D-R curves for bethanechol (IV) induced increases in LESP, and compared these values to changes in LESP after acute and chronic EtOH. EtOH was given to cats acutely or chronically. The number of mAChR sites (Bmax) in esophagus was lowered by acute EtOH, withdrawal from chronic EtOH raised Bmax. Acute injection of EtOH to cats in withdrawal reversed this increase in mAChR density. These changes correlated with the earlier data on EtOH-induced changes in LESP. In contrast, the D-R curve for bethanechol shifted to the right. Thus, the withdrawal-associated increase in Bmax is more likely to be a compensatory response to deficits distal to the receptor recognition site than to proximal deficits and doesn't cause LESP hyperactivity. Also, receptor binding changes do not necessarily translate into physiological changes.

  1. DOSE-DEPENDENT INCREASE IN THE PRODUCTION OF NERVE GROWTH FACTOR, NEUROTROPHIN-3, AND NEUROTROPHIN-4 IN A PENICILLIUM CHRYSOGENUM-INDUCED ALLERGIC ASTHMA MODEL

    EPA Science Inventory


    Increased levels of neurotrophins (nerve growth factor [NGF], brain-derived neurotrophic factor [BDNF], neurotrophin [NT]-3, and/or NT-4) have been associated with asthma as well as in animal models of allergic asthma. In our mouse model for fungal allergic asthma, repeated ...

  2. Fragment-based discovery of type I inhibitors of maternal embryonic leucine zipper kinase.

    PubMed

    Johnson, Christopher N; Berdini, Valerio; Beke, Lijs; Bonnet, Pascal; Brehmer, Dirk; Coyle, Joseph E; Day, Phillip J; Frederickson, Martyn; Freyne, Eddy J E; Gilissen, Ron A H J; Hamlett, Christopher C F; Howard, Steven; Meerpoel, Lieven; McMenamin, Rachel; Patel, Sahil; Rees, David C; Sharff, Andrew; Sommen, François; Wu, Tongfei; Linders, Joannes T M

    2015-01-01

    Fragment-based drug design was successfully applied to maternal embryonic leucine zipper kinase (MELK). A low affinity (160 μM) fragment hit was identified, which bound to the hinge region with an atypical binding mode, and this was optimized using structure-based design into a low-nanomolar and cell-penetrant inhibitor, with a good selectivity profile, suitable for use as a chemical probe for elucidation of MELK biology. PMID:25589925

  3. Regulation of transaminase C synthesis in Escherichia coli: conditional leucine auxotrophy.

    PubMed

    McGilvray, D; Umbarger, H E

    1974-11-01

    The regulation of synthesis of the valine-alanine-alpha-aminobutyrate transaminase (transaminase C) was studied in Escherichia coli mutants lacking the branched-chain amino acid transaminase (transaminase B). An investigation was made of two strains, CU2 and CU2002, each carrying the same transaminase B lesion but exhibiting different growth responses on a medium supplemented with branched-chain amino acids. Both had the absolute isoleucine requirement characteristic of ilvE auxotrophs, but growth of strain CU2 was stimulated by valine, whereas that of strain CU2002 was markedly inhibited by valine. Strain CU2002 behaved like a conditional leucine auxotroph in that the inhibition by valine was reversed by leucine. Results of enzymatic studies showed that synthesis of transaminase C was repressed by valine in strain CU2002 but not in strain CU2. Inhibition by valine in strain CU2002 appears to be the combined effect of repression on transaminase C synthesis and valine-dependent feedback inhibition of alpha-acetohydroxy acid synthase activity, causing alpha-ketoisovalerate (and hence leucine) limitation. The ilvE markers of strains CU2 and CU2002 were each transferred by transduction to a wild-type genetical background. All ilvE recombinants from both crosses resembled strain CU2002 and were inhibited by valine in the presence of isoleucine. Thus, strain CU2 carries an additional lesion that allows it to grow on a medium containing isoleucine plus valine. It is concluded that conditional leucine auxotrophy is characteristic of mutants carrying an ilvE lesion alone. PMID:4616947

  4. Lysine and Leucine Deficiencies Affect Myocytes Development and IGF Signaling in Gilthead Sea Bream (Sparus aurata)

    PubMed Central

    Azizi, Sheida; Nematollahi, Mohammad Ali; Mojazi Amiri, Bagher; Vélez, Emilio J.; Lutfi, Esmail; Navarro, Isabel; Capilla, Encarnación; Gutiérrez, Joaquim

    2016-01-01

    Optimizing aquaculture production requires better knowledge of growth regulation and improvement in diet formulation. A great effort has been made to replace fish meal for plant protein sources in aquafeeds, making necessary the supplementation of such diets with crystalline amino acids (AA) to cover the nutritional requirements of each species. Lysine and Leucine are limiting essential AA in fish, and it has been demonstrated that supplementation with them improves growth in different species. However, the specific effects of AA deficiencies in myogenesis are completely unknown and have only been studied at the level of hepatic metabolism. It is well-known that the TOR pathway integrates the nutritional and hormonal signals to regulate protein synthesis and cell proliferation, to finally control muscle growth, a process also coordinated by the expression of myogenic regulatory factors (MRFs). This study aimed to provide new information on the impact of Lysine and Leucine deficiencies in gilthead sea bream cultured myocytes examining their development and the response of insulin-like growth factors (IGFs), MRFs, as well as key molecules involved in muscle growth regulation like TOR. Leucine deficiency did not cause significant differences in most of the molecules analyzed, whereas Lysine deficiency appeared crucial in IGFs regulation, decreasing significantly IGF-I, IGF-II and IGF-IRb mRNA levels. This treatment also down-regulated the gene expression of different MRFs, including Myf5, Myogenin and MyoD2. These changes were also corroborated by a significant decrease in proliferation and differentiation markers in the Lysine-deficient treatment. Moreover, both Lysine and Leucine limitation induced a significant down-regulation in FOXO3 gene expression, which deserves further investigation. We believe that these results will be relevant for the production of a species as appreciated for human consumption as it is gilthead sea bream and demonstrates the importance of

  5. Structural and functional evolution of isopropylmalate dehydrogenases in the leucine and glucosinolate pathways of Arabidopsis thaliana

    SciTech Connect

    He, Yan; Galant, Ashley; Pang, Qiuying; Strul, Johanna M.; Balogun, Sherifat F.; Jez, Joseph M.; Chen, Sixue

    2012-10-24

    The methionine chain-elongation pathway is required for aliphatic glucosinolate biosynthesis in plants and evolved from leucine biosynthesis. In Arabidopsis thaliana, three 3-isopropylmalate dehydrogenases (AtIPMDHs) play key roles in methionine chain-elongation for the synthesis of aliphatic glucosinolates (e.g. AtIPMDH1) and leucine (e.g. AtIPMDH2 and AtIPMDH3). Here we elucidate the molecular basis underlying the metabolic specialization of these enzymes. The 2.25 {angstrom} resolution crystal structure of AtIPMDH2 was solved to provide the first detailed molecular architecture of a plant IPMDH. Modeling of 3-isopropylmalate binding in the AtIPMDH2 active site and sequence comparisons of prokaryotic and eukaryotic IPMDH suggest that substitution of one active site residue may lead to altered substrate specificity and metabolic function. Site-directed mutagenesis of Phe-137 to a leucine in AtIPMDH1 (AtIPMDH1-F137L) reduced activity toward 3-(2'-methylthio)ethylmalate by 200-fold, but enhanced catalytic efficiency with 3-isopropylmalate to levels observed with AtIPMDH2 and AtIPMDH3. Conversely, the AtIPMDH2-L134F and AtIPMDH3-L133F mutants enhanced catalytic efficiency with 3-(2'-methylthio)ethylmalate {approx}100-fold and reduced activity for 3-isopropylmalate. Furthermore, the altered in vivo glucosinolate profile of an Arabidopsis ipmdh1 T-DNA knock-out mutant could be restored to wild-type levels by constructs expressing AtIPMDH1, AtIPMDH2-L134F, or AtIPMDH3-L133F, but not by AtIPMDH1-F137L. These results indicate that a single amino acid substitution results in functional divergence of IPMDH in planta to affect substrate specificity and contributes to the evolution of specialized glucosinolate biosynthesis from the ancestral leucine pathway.

  6. Site reactivity in the free radicals induced damage to leucine residues: a theoretical study.

    PubMed

    Medina, M E; Galano, A; Alvarez-Idaboy, J R

    2015-02-21

    Several recent computational studies have tried to explain the observed selectivity in radical damage to proteins. In this work we use Density Functional Theory and Transition State Theory including tunnelling corrections, reaction path degeneracy, the effect of diffusion, and the role of free radicals to get further insights into this important topic. The reaction between a leucine derivative and free radicals of biological significance, in aqueous and lipid media, has been investigated. Both thermochemical and kinetic analyses, in both hydrophilic and hydrophobic environments, have been carried out. DPPH, ˙OOH, ˙OOCH3, ˙OOCH2Cl, ˙OOCHCl2 and ˙OOCHCH2 radicals do not react with the target molecule. The reactions are proposed to be kinetically controlled. The leucine gamma site was the most reactive for the reactions with ˙N3, ˙OOCCl3, ˙OCH3, ˙OCH2Cl, and ˙OCHCl2 radicals, with rate constants equal to 1.97 × 10(5), 3.24 × 10(4), 6.68 × 10(5), 5.98 × 10(6) and 8.87 × 10(8) M(-1) s(-1), respectively, in aqueous solution. The ˙Cl, ˙OH and ˙OCCl3 radicals react with leucine at the beta, gamma, and delta positions at rates close to the diffusion limit with the alpha position which is the slowest path and the most thermodynamically favored. The presented results confirm that the Bell-Evans-Polanyi principle does not apply for the reactions between amino acid residues and free radicals. Regarding the influence of the environment on the reactivity of the studied series of free radicals towards leucine residues, it is concluded that hydrophilic media slightly lower the reactivity of the studied radicals, compared to hydrophobic ones, albeit the trends in reactivity are very similar. PMID:25592549

  7. Fragment-Based Discovery of Type I Inhibitors of Maternal Embryonic Leucine Zipper Kinase

    PubMed Central

    2014-01-01

    Fragment-based drug design was successfully applied to maternal embryonic leucine zipper kinase (MELK). A low affinity (160 μM) fragment hit was identified, which bound to the hinge region with an atypical binding mode, and this was optimized using structure-based design into a low-nanomolar and cell-penetrant inhibitor, with a good selectivity profile, suitable for use as a chemical probe for elucidation of MELK biology. PMID:25589925

  8. Leucine incorporation by aerobic anoxygenic phototrophic bacteria in the Delaware estuary

    PubMed Central

    Stegman, Monica R; Cottrell, Matthew T; Kirchman, David L

    2014-01-01

    Aerobic anoxygenic phototrophic (AAP) bacteria are well known to be abundant in estuaries, coastal regions and in the open ocean, but little is known about their activity in any aquatic ecosystem. To explore the activity of AAP bacteria in the Delaware estuary and coastal waters, single-cell 3H-leucine incorporation by these bacteria was examined with a new approach that combines infrared epifluorescence microscopy and microautoradiography. The approach was used on samples from the Delaware coast from August through December and on transects through the Delaware estuary in August and November 2011. The percent of active AAP bacteria was up to twofold higher than the percentage of active cells in the rest of the bacterial community in the estuary. Likewise, the silver grain area around active AAP bacteria in microautoradiography preparations was larger than the area around cells in the rest of the bacterial community, indicating higher rates of leucine consumption by AAP bacteria. The cell size of AAP bacteria was 50% bigger than the size of other bacteria, about the same difference on average as measured for activity. The abundance of AAP bacteria was negatively correlated and their activity positively correlated with light availability in the water column, although light did not affect 3H-leucine incorporation in light–dark experiments. Our results suggest that AAP bacteria are bigger and more active than other bacteria, and likely contribute more to organic carbon fluxes than indicated by their abundance. PMID:24824666

  9. Phase Shift of the Circadian Rhythm of Lemna Caused by Pulses of a Leucine Analog, Trifluoroleucine

    PubMed Central

    Kondo, Takao

    1988-01-01

    Pulses of a fluorinated analog of leucine, 5′,5′,5′-trifluoroleucine, reset the phase of the circadian rhythm of K+ uptake in Lemna gibba G3 under continuous light conditions. The trifluoroleucine pulse caused the largest delay phase-shifts during the early subjective phase but it caused only small phase advances. The action of trifluoroleucine was investigated and the following results were obtained. (a) The uptake of trifluoroleucine was essentially the same at all circadian phases, even though phase shifting was dramatically different at different phases. At effective phases, the magnitude of phase shifting was well correlated with the amount of trifluoroleucine taken up by the duckweed. (b) The trifluoroleucine pulse lowered the endogenous content of valine and leucine but these decreases did not correlate with phase shifting. (c) Protein synthesis was not affected by trifluoroleucine pulses which caused large phase shifts. (d) Pulses of 4-azaleucine, a different structural analog of leucine, also caused phase shifting. However, neither the direction nor the effective times of phase shifting were similar to those of trifluoroleucine. Taken together, these results negate the proposition that trifluoroleucine and azaleucine caused phase shift by disturbing amino acid metabolism and/or inhibiting protein synthesis, but they suggest instead that these analogs are incorporated into some protein(s) which are necessary for normal clock operation. PMID:16666410

  10. Leucine metabolism regulates TRI6 expression and affects deoxynivalenol production and virulence in Fusarium graminearum.

    PubMed

    Subramaniam, Rajagopal; Narayanan, Swara; Walkowiak, Sean; Wang, Li; Joshi, Manisha; Rocheleau, Hélène; Ouellet, Thérèse; Harris, Linda J

    2015-11-01

    TRI6 is a positive regulator of the trichothecene gene cluster and the production of trichothecene mycotoxins [deoxynivalenol (DON)] and acetylated forms such as 15-Acetyl-DON) in the cereal pathogen Fusarium graminearum. As a global transcriptional regulator, TRI6 expression is modulated by nitrogen-limiting conditions, sources of nitrogen and carbon, pH and light. However, the mechanism by which these diverse environmental factors affect TRI6 expression remains underexplored. In our effort to understand how nutrients affect TRI6 regulation, comparative digital expression profiling was performed with a wild-type F. graminearum and a Δtri6 mutant strain, grown in nutrient-rich conditions. Analysis showed that TRI6 negatively regulates genes of the branched-chain amino acid (BCAA) metabolic pathway. Feeding studies with deletion mutants of MCC, encoding methylcrotonyl-CoA-carboxylase, one of the key enzymes of leucine metabolism, showed that addition of leucine specifically down-regulated TRI6 expression and reduced 15-ADON accumulation. Constitutive expression of TRI6 in the Δmcc mutant strain restored 15-ADON production. A combination of cellophane breach assays and pathogenicity experiments on wheat demonstrated that disrupting the leucine metabolic pathway significantly reduced disease. These findings suggest a complex interaction between one of the primary metabolic pathways with a global regulator of mycotoxin biosynthesis and virulence in F. graminearum. PMID:26248604

  11. Conversion of L-leucine to isovaleric acid by Propionibacterium freudenreichii TL 34 and ITGP23.

    PubMed

    Thierry, Anne; Maillard, Marie-Bernadette; Yvon, Mireille

    2002-02-01

    Several branched-chain volatile compounds are involved in the flavor of Swiss cheese. These compounds are probably produced by enzymatic conversion of branched-chain amino acids, but the flora and the pathways involved remain hypothetical. Our aim was to determine the ability of Propionibacterium freudenreichii, which is one of the main components of the secondary flora of Swiss cheese, to produce flavor compounds during leucine catabolism. Cell extracts and resting cells of two strains were incubated in the presence of L-leucine, alpha-ketoglutaric acid, and cofactors, and the metabolites produced were determined by high-performance liquid chromatography and gas chromatography. The first step of leucine catabolism was a transamination that produced alpha-ketoisocaproic acid, which was enzymatically converted to isovaleric acid. Both reactions were faster at pH 8.0 than at acidic pHs. Cell extracts catalyzed only the transamination step under our experimental conditions. Small amounts of 3-methylbutanol were also produced by resting cells, but neither 3-methylbutanal noralpha-hydroxyisocaproic acid was detected. L-Isoleucine and L-valine were also converted to the corresponding acids and alcohols. Isovaleric acid was produced by both strains during growth in a complex medium, even under conditions simulating Swiss cheese conditions (2.1% NaCl, pH 5.4, 24 degrees C). Our results show that P. frendenreichii could play a significant role in the formation of isovaleric acid during ripening. PMID:11823198

  12. Specific regulatory interconnection between the leucine and histidine pathways of Neurospora crassa.

    PubMed Central

    Kidd, G L; Gross, S R

    1984-01-01

    Leucine auxotrophs of Neurospora fall into two discrete categories with respect to sensitivity to the herbicide, 3-amino-1,2,4-triazole. The pattern of resistance corresponds exactly to the ability to produce the leucine pathway control elements, alpha-isopropylmalate and the leu-3 product. An analysis of the regulatory response of the production of enzymes of histidine biosynthesis to alpha-isopropylmalate implicates the control elements of the leucine pathway as important components of the mechanism governing the production of the target enzyme of aminotriazole inhibition, imidazoleglycerol-phosphate dehydratase (EC 4.2.1.19). The evidence suggests that the regulatory interconnection between the two pathways is direct and is independent of other general integrating regulatory mechanisms which appear to be operative in both pathways. A general method for isolating leu-1 and leu-2, as well as other regulatory mutants, is described, which takes advantage of the specificity of the resistance to the inhibitor. Use of analogous systems is prescribed for the analysis of other regulatory interconnections which, like this one, might not be anticipated directly from structural or biosynthetic considerations. PMID:6325383

  13. Estimation of whole body protein synthesis from oxidation of infused [1-14C]leucine.

    PubMed

    Yagi, M; Walser, M

    1990-01-01

    In rats infused with NaH14CO3, 14CO2 exhalation approached an asymptotic rate equal to 96.0 +/- 1.3 (SD) % of the infusion rate of 14C in a monoexponential manner with a half-time of 20 min. In rats infused with [1-14C]leucine, 14CO2 exhalation (/0.96) approached an asymptotic value, (1-F), of 16-25% of 14C infusion rate (mean 20.4%) in a monoexponential manner with a half-time of approximately 31 min. Whole body protein synthesis (S) was calculated from 1-F and urea N plus ammonia N excretion (C) as S = CF/(1-F). S was a uniform function of body weight in these rats, in six additional rats in which S was measured 6 h after single intravenous injection of [1-14C]leucine and also in previously reported rats given single injections. The relationship was S (mg.100 g-1.h-1) = 11-0.143 body wt (g) +/- 8.3. In six of these rats, S was also estimated from the plateau specific activity of plasma leucine or plasma 2-ketoisocaproate (KIC); the former estimate of S was significantly lower (by an average of 17%), but S was the same when specific activity of KIC was employed. These results support the validity of the expired 14CO2 technique for measuring S. PMID:2154116

  14. Trp387 and the putative leucine zippers of PGH synthases-1 and -2.

    PubMed

    Hsi, L C; Tsai, A L; Kulmacz, R J; English, D G; Siefker, A O; Otto, J C; Smith, W L

    1993-01-01

    The active site sequence 385-YHWH-388 of ovine prostaglandin endoperoxide synthase-1 (PGHS-1) has residues critical for cyclooxygenase and peroxidase catalysis. Tyr385 is essential for cyclooxygenase activity, His386, for peroxidase activity, and His388, for both activities. To determine the importance of Trp387, we used site-directed mutagenesis to replace Trp387 of PGHS-1 with arginine, phenylalanine, and serine. W387R and W387S lacked significant activity. W387F retained both cyclooxygenase and peroxidase activities. Thus, we conclude that Trp387 is not essential for catalysis by PGHS-1. Purified PGHS-1 is a homodimer. There are two putative leucine zipper regions in ovine PGHS-1 involving residues 345-366 and 487-508. We tested for a role of these leucine zippers as determinants of dimer formation. Helix-breaking proline mutations were introduced at Leu359 or Leu501. Neither of these residues proved to be essential for peroxidase activity; but, mutations at each residue greatly reduced or eliminated cyclooxygenase activity. Both mutant proteins chromatographed as dimers on Sephacryl G-200. Thus, neither of these putative leucine zipper regions alone is responsible for PGHS-1 dimer formation. PMID:8357979

  15. Fluid flow increases mineralized matrix deposition in 3D perfusion culture of marrow stromal osteoblasts in a dose-dependent manner

    NASA Technical Reports Server (NTRS)

    Bancroft, Gregory N.; Sikavitsas, Vassilios I.; van den Dolder, Juliette; Sheffield, Tiffany L.; Ambrose, Catherine G.; Jansen, John A.; Mikos, Antonios G.; McIntire, L. V. (Principal Investigator)

    2002-01-01

    Bone is a complex highly structured mechanically active 3D tissue composed of cellular and matrix elements. The true biological environment of a bone cell is thus derived from a dynamic interaction between responsively active cells experiencing mechanical forces and a continuously changing 3D matrix architecture. To investigate this phenomenon in vitro, marrow stromal osteoblasts were cultured on 3D scaffolds under flow perfusion with different rates of flow for an extended period to permit osteoblast differentiation and significant matrix production and mineralization. With all flow conditions, mineralized matrix production was dramatically increased over statically cultured constructs with the total calcium content of the cultured scaffolds increasing with increasing flow rate. Flow perfusion induced de novo tissue modeling with the formation of pore-like structures in the scaffolds and enhanced the distribution of cells and matrix throughout the scaffolds. These results represent reporting of the long-term effects of fluid flow on primary differentiating osteoblasts and indicate that fluid flow has far-reaching effects on osteoblast differentiation and phenotypic expression in vitro. Flow perfusion culture permits the generation and study of a 3D, actively modeled, mineralized matrix and can therefore be a valuable tool for both bone biology and tissue engineering.

  16. Lean body mass change over 6 years is associated with dietary leucine intake in an older Danish population.

    PubMed

    McDonald, Cameron Keith; Ankarfeldt, Mikkel Z; Capra, Sandra; Bauer, Judy; Raymond, Kyle; Heitmann, Berit Lilienthal

    2016-05-01

    Higher protein intake, and particularly higher leucine intake, is associated with attenuated loss of lean body mass (LBM) over time in older individuals. Dietary leucine is thought to be a key mediator of anabolism. This study aimed to assess this relationship over 6 years among younger and older adult Danes. Dietary leucine intake was assessed at baseline and after 6 years in men and women, aged 35-65 years, participating in the Danish cohort of the WHO-MONICA (Multinational MONItoring of trends and determinants in CArdiovascular disease) study (n 368). Changes in LBM over the 6 years were measured by bioelectrical impedance using equations developed for this Danish population. The association between leucine and LBM changes was examined using multivariate linear regression and ANCOVA analyses adjusted for potential confounders. After adjustment for baseline LBM, sex, age, energy intake and physical activity, leucine intake was associated with LBM change in those older than 65 years (n 79), with no effect seen in those younger than 65 years. Older participants in the highest quartile of leucine intake (7·1 g/d) experienced LBM maintenance, whereas lower intakes were associated with LBM loss over 6 years (for trend: β=0·434, P=0·03). Sensitivity analysis indicated no effect modification of sex or the presence of CVD. Greater leucine intake in conjunction with adequate total protein intake was associated with long-term LBM retention in a healthy older Danish population. This study corroborates findings from laboratory investigations in relation to protein and leucine intakes and LBM change. A more diverse and larger sample is needed for confirmation of these results. PMID:26979049

  17. Altered metabolic incorporation of fucose and leucine into PNS myelin of 25-week-old diabetic (C57BL/Ks (db/db)) mice: effects of untreated diabetes on nerve metabolism

    SciTech Connect

    Chez, M.G.; Peterson, R.G.

    1983-04-01

    Sciatic nerves of 25-week-old genetically diabetic (C57BL/Ks (db/db)) mice and their litter-mate controls were removed, and their metabolic incorporation of (/sup 3/H)fucose and (/sup 14/C)leucine into myelin was studied in vitro. Untreated diabetic animals showed significant increases (p less than 0.05) in the fucose/leucine incorporation into myelin when compared to values found for their litter-mates. These results correlated well with previous experiments performed on alloxan or streptozotocin-diabetic rats and thus show the in vitro incubation procedure to be a good indicator of altered metabolic conditions in peripheral nerves due to diabetes mellitus. The resulting ratio increases seen in diabetic animals is at variance with the decrease in ratios found in animals undergoing typical Wallerian degeneration. These results suggest that different metabolic processes operate in untreated diabetics than in normals or in those undergoing other degenerative nerve processes.

  18. Biosynthesis of 4-methyleneglutamic acid by peanut seedlings: Evidence for the involvement of a distinct source of leucine

    SciTech Connect

    Winter, H.C.; Dekker, E.E. )

    1989-04-01

    Germinating peanut seeds accumulate 4-methyleneglutamic acid its {gamma}-amide(MeGlx), as well as 4-methylglutamic acid(MGlu) for which leucine has been implicated as a precursor. When we incubated detached peanut cotyledons with {sup 14}C-leucine for 24-96 hr, most of the label was found in non-extractable components, while small but significant amounts were present in MeGlx, MGlu, and free leucine. The level of leucine in storage protein of ungerminated seeds is similar to the maximum level of MeGlx found in germinated seeds; further correlations were observed in various peanut tissues between rapid accumulation of MeGlx and the presence of high levels of glyoxysomal enzymes (catalase and isocitrate lyase). These results suggest that during germination, most of the leucine in the seed storage protein is converted to MeGlx, possibly by a glyoxysomal oxidase system in cotyledons, whereas most of the free leucine for protein synthesis is formed de novo.

  19. Discovery and application of new bacterial strains for asymmetric synthesis of L-tert-butyl leucine in high enantioselectivity.

    PubMed

    Jin, Jian-Zhong; Chang, Dong-Liang; Zhang, Jie

    2011-06-01

    Discovery of new bacterial strains with fast identification in a miniaturized system was performed for the synthesis of optically active L-tert-butyl leucine. With tert-butyl leucine amide as nitrogen source, one bacterial strain with high conversion and high enantioselectivity was discovered among 120 isolated microorganisms from local soils and identified as Mycobacterium sp. JX009. Glucose and ammonium chloride were examined as the good carbon source and nitrogen source for the cells' growth separately. The cells grew better at 30 °C and at pH 7.5 with higher activity of 2,650 U/l in comparison with other conditions. Cells' stability was improved by immobilization on synthetic resin 0730 without pretreatment. Tert-butyl leucine amide (30 mM) was successfully hydrolyzed by immobilized cells and examined as the highest chemical concentration that cells could endure. After six reaction cycles, the immobilized cells retained 90% activity with production of L-tert-butyl leucine in 98% ee. The results firstly reported the application of new bacterial strain in the hydrolysis of tert-butyl leucine amide to produce optically active L-tert-butyl leucine in an efficient way with investigation in detail. PMID:21153891

  20. Leucine supplementation is anti-atrophic during paradoxical sleep deprivation in rats.

    PubMed

    de Sá Souza, Helton; Antunes, Hanna Karen Moreira; Dáttilo, Murilo; Lee, Kil Sun; Mônico-Neto, Marcos; de Campos Giampa, Sara Quaglia; Phillips, Stuart M; Tufik, Sergio; de Mello, Marco Túlio

    2016-04-01

    The purpose of this study was to identify sleep deprivation-induced atrophy and the muscle-specific fiber types affected and to determine the effects of leucine supplementation on atrophy and pertinent portions of the pathways of muscle protein synthesis and degradation in rats. A total of 46 Wistar rats were distributed in four groups: control (CTL), leucine supplementation (LEU), sleep deprivation (SD), and leucine supplementation + sleep deprivation (LEU + SD). Leucine supplementation was by gavage (1.35 g/kg/daily), and the animals were subjected to SD for 96 h. Testosterone and corticosterone concentrations, along with proteins involved in protein synthesis and degradation and proteasome activity levels, were measured in the gastrocnemius (GA) muscle. Myosin ATPase staining was used to evaluate the different muscle fibers. After sleep deprivation, GA muscle and body masses decreased in the SD group compared to the CTL, LEU, and LEU + SD groups. There was no difference between groups in type I fiber cross-sectional area (CSA). The CSAs for type IIa fibers were lower in the SD and LEU + SD groups vs. the CTL and LEU groups, while the IIb fiber CSA was lower in the SD group vs. the CSAs in all other groups. The phospho (p)-Akt levels were lower in the SD and LEU + SD groups vs. the CTL and LEU groups. The p-mTORC1 levels were higher in the LEU, SD, and LEU + SD groups vs. the CTL group. The p-p70S6k levels were higher in the LEU and LEU + SD groups; the 4E-BP1 levels were higher in the SD and LEU + SD groups compared to those in the CTL and LEU groups, and the p-4E-BP1 levels were higher in the LEU and SD groups compared to those in the CTL group and even higher in the LEU + SD group compared to those in the LEU and SD groups. Ubiquitinated proteins, LC3, and p62/SQSTM, and proteasome activity levels were higher in the SD and LEU + SD groups vs. the LEU and CTL groups. Sleep deprivation led to the atrophy of IIa and IIb muscle fibers; however, leucine

  1. The mTORC1/4E-BP pathway coordinates hemoglobin production with L-leucine availability.

    PubMed

    Chung, Jacky; Bauer, Daniel E; Ghamari, Alireza; Nizzi, Christopher P; Deck, Kathryn M; Kingsley, Paul D; Yien, Yvette Y; Huston, Nicholas C; Chen, Caiyong; Schultz, Iman J; Dalton, Arthur J; Wittig, Johannes G; Palis, James; Orkin, Stuart H; Lodish, Harvey F; Eisenstein, Richard S; Cantor, Alan B; Paw, Barry H

    2015-01-01

    In multicellular organisms, the mechanisms by which diverse cell types acquire distinct amino acids and how cellular function adapts to their availability are fundamental questions in biology. We found that increased neutral essential amino acid (NEAA) uptake was a critical component of erythropoiesis. As red blood cells matured, expression of the amino acid transporter gene Lat3 increased, which increased NEAA import. Inadequate NEAA uptake by pharmacologic inhibition or RNAi-mediated knockdown of LAT3 triggered a specific reduction in hemoglobin production in zebrafish embryos and murine erythroid cells through the mTORC1 (mammalian target of rapamycin complex 1)/4E-BP (eukaryotic translation initiation factor 4E-binding protein) pathway. CRISPR-mediated deletion of members of the 4E-BP family in murine erythroid cells rendered them resistant to mTORC1 and LAT3 inhibition and restored hemoglobin production. These results identify a developmental role for LAT3 in red blood cells and demonstrate that mTORC1 serves as a homeostatic sensor that couples hemoglobin production at the translational level to sufficient uptake of NEAAs, particularly L-leucine. PMID:25872869

  2. The mTORC1/4E-BP pathway coordinates hemoglobin production with L-leucine availability

    PubMed Central

    Chung, Jacky; Bauer, Daniel E.; Ghamari, Alireza; Nizzi, Christopher P.; Deck, Kathryn M.; Kingsley, Paul D.; Yien, Yvette Y.; Huston, Nicholas C.; Chen, Caiyong; Schultz, Iman J.; Dalton, Arthur J.; Wittig, Johannes G.; Palis, James; Orkin, Stuart H.; Lodish, Harvey F.; Eisenstein, Richard S.; Cantor, Alan B.; Paw, Barry H.

    2015-01-01

    In multicellular organisms, the mechanisms by which diverse cell types acquire distinct amino acids and how cellular function adapts to their availability are fundamental questions in biology. Here, we found that increased neutral essential amino acid (NEAA) uptake was a critical component of erythropoiesis. As red blood cells matured, expression of the amino acid transporter gene Lat3 increased, which increased NEAA import. Inadequate NEAA uptake by pharmacologic inhibition or RNAi-mediated knockdown of LAT3 triggered a specific reduction in hemoglobin production in zebrafish embryos and murine erythroid cells through the mTORC1 (mechanistic target of rapamycin complex 1)/4E-BP (eukaryotic translation initiation factor 4E-binding protein) pathway. CRISPR-mediated deletion of members of the 4E-BP family in murine erythroid cells rendered them resistant to mTORC1 and LAT3 inhibition and restored hemoglobin production. These results identify a developmental role for LAT3 in red blood cells and demonstrate that mTORC1 serves as a homeostatic sensor that couples hemoglobin production at the translational level to sufficient uptake of NEAAs, particularly L-leucine. PMID:25872869

  3. Chronic Treatment with a Clinically Relevant Dose of Methylphenidate Increases Glutamate Levels in Cerebrospinal Fluid and Impairs Glutamatergic Homeostasis in Prefrontal Cortex of Juvenile Rats.

    PubMed

    Schmitz, Felipe; Pierozan, Paula; Rodrigues, André F; Biasibetti, Helena; Coelho, Daniella M; Mussulini, Ben Hur; Pereira, Mery S L; Parisi, Mariana M; Barbé-Tuana, Florencia; de Oliveira, Diogo L; Vargas, Carmen R; Wyse, Angela T S

    2016-05-01

    The understanding of the consequences of chronic treatment with methylphenidate is very important since this psychostimulant is extensively prescribed to preschool age children, and little is known about the mechanisms underlying the persistent changes in behavior and neuronal function related with the use of methylphenidate. In this study, we initially investigate the effect of early chronic treatment with methylphenidate on amino acids profile in cerebrospinal fluid and prefrontal cortex of juvenile rats, as well as on glutamatergic homeostasis, Na(+),K(+)-ATPase function, and balance redox in prefrontal cortex of rats. Wistar rats at early age received intraperitoneal injections of methylphenidate (2.0 mg/kg) or an equivalent volume of 0.9 % saline solution (controls), once a day, from the 15th to the 45th day of age. Twenty-four hours after the last injection, the animals were decapitated and the cerebrospinal fluid and prefrontal cortex were obtained. Results showed that methylphenidate altered amino acid profile in cerebrospinal fluid, increasing the levels of glutamate. Glutamate uptake was decreased by methylphenidate administration, but GLAST and GLT-1 were not altered by this treatment. In addition, the astrocyte marker GFAP was not altered by MPH. The activity and immunocontent of catalytic subunits (α1, α2, and α3) of Na(+),K(+)-ATPase were decreased in prefrontal cortex of rats subjected to methylphenidate treatment, as well as changes in α1 and α2 gene expression of catalytic α subunits of Na(+),K(+)-ATPase were also observed. CAT activity was increased and SOD/CAT ratio and sulfhydryl content were decreased in rat prefrontal cortex. Taken together, our results suggest that chronic treatment with methylphenidate at early age induces excitotoxicity, at least in part, due to inhibition of glutamate uptake probably caused by disturbances in the Na(+),K(+)-ATPase function and/or in protein damage observed in the prefrontal cortex. PMID:26001762

  4. Effects of steroids and sex reversal on intestinal absorption of L-(/sup 14/C)leucine in vivo, in rainbow trout, Salmo gairdneri

    SciTech Connect

    Habibi, H.R.; Ince, B.W.

    1983-12-01

    The effects of steroids (17 alpha-methyltestosterone (MT), 17 beta-oestradiol (E2)), and of sex reversal (XX male) on intestinal absorption and accumulation of L-(/sup 14/C)leucine (5 mM), were investigated in unanaesthetized rainbow trout (Salmo gairdneri), using an in vivo gut perfusion technique. Each steroid was luminally perfused through the gut at a concentration of 50 micrograms/ml perfusate, during five separate perfusions carried out on the same fish at 30-min intervals (perfusion periods 1 to 5), for a total of 120 min at 14 degrees. Experiments were also conducted on masculinized, genetically female trout (XX male) with steroid-free perfusate. MT treatment significantly increased the intestinal absorption of radioleucine during periods 1 and 2, whilst E2 was without effect. Neither MT nor E2 influenced intestinal accumulation (mid- and hindgut) of radioleucine, and accumulation of /sup 14/C-solutes in skeletal muscle. Sex reversal, however, whilst having no effect on leucine absorption, nevertheless significantly increased intestinal accumulation of radioleucine, and accumulation of /sup 14/C-solutes in skeletal muscle. The effects observed in the present study are in agreement with previous work in trout using everted gut sac preparations. It is suggested that the growth-promoting effects of anabolic-androgenic steroids in fish may be partly explained by their action on gastrointestinal function.

  5. Amino acid transport across the tonoplast of vacuoles isolated from barley mesophyll protoplasts: Uptake of alanine, leucine, and glutamine. [Hordeum vulgare L

    SciTech Connect

    Dietz, K.J.; Jaeger, R.; Kaiser, G.; Martinoia, E. )

    1990-01-01

    Mesophyll protoplasts from leaves of well-fertilized barley (Hordeum vulgare L.) plants contained amino acids at concentrations as high as 120 millimoles per liter. With the exception of glutamic acid, which is predominantly localized in the cytoplasm, a major part of all other amino acids was contained inside the large central vacuole. Alanine, leucine, and glutamine are the dominant vacuolar amino acids in barley. Their transport into isolated vacuoles was studied using {sup 14}C-labeled amino acids. Uptake was slow in the absence of ATP. A three- to sixfold stimulation of uptake was observed after addition of ATP or adenylyl imidodiphosphate an ATP analogue not being hydrolyzed by ATPases. Other nucleotides were ineffective in increasing the rate of uptake. ATP-Stimulated amino acid transport was not dependent on the transtonoplast pH or membrane potential. p-Chloromercuriphenylsulfonic acid and n-ethyl maleimide increased transport independently of ATP. Neutral amino acids such as valine or leucine effectively decreased the rate of alanine transport. Glutamine and glycine were less effective or not effective as competitive inhibitors of alanine transport. The results indicate the existence of a uniport translocator specific for neutral or basic amino acids that is under control of metabolic effectors.

  6. Environmental neurotoxin interaction with proteins: Dose-dependent increase of free and protein-associated BMAA (β-N-methylamino-L-alanine) in neonatal rat brain.

    PubMed

    Karlsson, Oskar; Jiang, Liying; Ersson, Lisa; Malmström, Tim; Ilag, Leopold L; Brittebo, Eva B

    2015-01-01

    β-Methylamino-L-alanine (BMAA) is implicated in the aetiology of neurodegenerative disorders. Neonatal exposure to BMAA induces cognitive impairments and progressive neurodegenerative changes including intracellular fibril formation in the hippocampus of adult rats. It is unclear why the neonatal hippocampus is especially vulnerable and the critical cellular perturbations preceding BMAA-induced toxicity remains to be elucidated. The aim of this study was to compare the level of free and protein-associated BMAA in neonatal rat brain and peripheral tissues after different exposures to BMAA. Ultra-high performance liquid chromatography-tandem mass spectrometry analysis revealed that BMAA passed the neonatal blood-brain barrier and was distributed to all studied brain areas. BMAA was also associated to proteins in the brain, especially in the hippocampus. The level in the brain was, however, considerably lower compared to the liver that is not a target organ for BMAA. In contrast to the liver there was a significantly increased level of protein-association of BMAA in the hippocampus and other brain areas following repeated administration suggesting that the degradation of BMAA-associated proteins may be lower in neonatal brain than in the liver. Additional evidence is needed in support of a role for protein misincorporation in the neonatal hippocampus for long-term effects of BMAA. PMID:26498001

  7. Antidepressant dose of taurine increases mRNA expression of GABAA receptor α2 subunit and BDNF in the hippocampus of diabetic rats.

    PubMed

    Caletti, Greice; Almeida, Felipe Borges; Agnes, Grasiela; Nin, Maurício Schüler; Barros, Helena Maria Tannhauser; Gomez, Rosane

    2015-04-15

    Diabetes mellitus is a metabolic disorder associated with higher risk for depression. Diabetic rats present depressive-like behaviors and taurine, one of the most abundant free amino acids in the brain, reverses this depressive behaviors. Because taurine is a GABAA agonist modulator, we hypothesize that its antidepressant effect results from the interaction on this system by changing α2 GABAA receptor subunit expression, beside changes on BDNF mRNA, and memory in diabetic rats. Streptozotocin-diabetic and non-diabetic Wistar rats were daily injected with 100mg/kg of taurine or saline, intraperitoneally, for 30 days. At the end of the experiment, rats were exposed to the novel object recognition memory. Later they were euthanized, the brains were weighed, and the hippocampus was dissected for α2 GABAA subunit and BDNF mRNA expression. Real-time quantitative PCR (qPCR) showed that diabetic rats presented lower α2 GABAA subunit and BDNF mRNA expression than non-diabetic rats and taurine increased both parameters in these sick rats. Taurine also reversed the lower brain weight and improved the short-term memory in diabetic rats. Thus, the taurine antidepressant effect may be explained by interference with the GABA system, in line to its neuroprotective effect showed here by preventing brain weight loss and improving memory in diabetic rats. PMID:25612506

  8. Low-dose carbon-based nanoparticle-induced effects in A549 lung cells determined by biospectroscopy are associated with increases in genomic methylation

    PubMed Central

    Li, Junyi; Tian, Meiping; Cui, Li; Dwyer, John; Fullwood, Nigel J.; Shen, Heqing; Martin, Francis L.

    2016-01-01

    Nanotechnology has introduced many manufactured carbon-based nanoparticles (CNPs) into our environment, generating a debate into their risks and benefits. Numerous nanotoxicology investigations have been carried, and nanoparticle-induced toxic effects have been reported. However, there remain gaps in our knowledge, primarily regarding mechanism. Herein, we assessed the global alterations induced by CNPs in A549 lung cells using biospectroscopy techniques, including attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy and surface-enhanced Raman spectroscopy (SERS). A549 cells were treated with fullerene (C60), long or short multi-walled carbon nanotubes, or single-walled carbon nanotubes at concentrations of 0.1 mg/L, 0.01 mg/L and 0.001 mg/L. Exposed cells were then analysed by ATR-FTIR spectroscopy and SERS. Spectra were pre-processed via computational analysis, and information on biochemical alterations in exposed cells were identified. Additionally, global DNA methylation levels in cells exposed to CNPs at 0.1 mg/L were determined using HPLC-MS and genetic regulators (for DNA methylation) were checked by quantitative real-time RT-PCR. It was found that CNPs exert marked effects in A549 cells and also contribute to increases in global DNA methylation. For the first time, this study highlights that real-world levels of nanoparticles can alter the methylome of exposed cells; this could have enormous implications for their regulatory assessment. PMID:26831369

  9. Low-dose carbon-based nanoparticle-induced effects in A549 lung cells determined by biospectroscopy are associated with increases in genomic methylation

    NASA Astrophysics Data System (ADS)

    Li, Junyi; Tian, Meiping; Cui, Li; Dwyer, John; Fullwood, Nigel J.; Shen, Heqing; Martin, Francis L.

    2016-02-01

    Nanotechnology has introduced many manufactured carbon-based nanoparticles (CNPs) into our environment, generating a debate into their risks and benefits. Numerous nanotoxicology investigations have been carried, and nanoparticle-induced toxic effects have been reported. However, there remain gaps in our knowledge, primarily regarding mechanism. Herein, we assessed the global alterations induced by CNPs in A549 lung cells using biospectroscopy techniques, including attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy and surface-enhanced Raman spectroscopy (SERS). A549 cells were treated with fullerene (C60), long or short multi-walled carbon nanotubes, or single-walled carbon nanotubes at concentrations of 0.1 mg/L, 0.01 mg/L and 0.001 mg/L. Exposed cells were then analysed by ATR-FTIR spectroscopy and SERS. Spectra were pre-processed via computational analysis, and information on biochemical alterations in exposed cells were identified. Additionally, global DNA methylation levels in cells exposed to CNPs at 0.1 mg/L were determined using HPLC-MS and genetic regulators (for DNA methylation) were checked by quantitative real-time RT-PCR. It was found that CNPs exert marked effects in A549 cells and also contribute to increases in global DNA methylation. For the first time, this study highlights that real-world levels of nanoparticles can alter the methylome of exposed cells; this could have enormous implications for their regulatory assessment.

  10. Environmental neurotoxin interaction with proteins: Dose-dependent increase of free and protein-associated BMAA (β-N-methylamino-L-alanine) in neonatal rat brain

    PubMed Central

    Karlsson, Oskar; Jiang, Liying; Ersson, Lisa; Malmström, Tim; Ilag, Leopold L.; Brittebo, Eva B.

    2015-01-01

    β-Methylamino-L-alanine (BMAA) is implicated in the aetiology of neurodegenerative disorders. Neonatal exposure to BMAA induces cognitive impairments and progressive neurodegenerative changes including intracellular fibril formation in the hippocampus of adult rats. It is unclear why the neonatal hippocampus is especially vulnerable and the critical cellular perturbations preceding BMAA-induced toxicity remains to be elucidated. The aim of this study was to compare the level of free and protein-associated BMAA in neonatal rat brain and peripheral tissues after different exposures to BMAA. Ultra-high performance liquid chromatography-tandem mass spectrometry analysis revealed that BMAA passed the neonatal blood-brain barrier and was distributed to all studied brain areas. BMAA was also associated to proteins in the brain, especially in the hippocampus. The level in the brain was, however, considerably lower compared to the liver that is not a target organ for BMAA. In contrast to the liver there was a significantly increased level of protein-association of BMAA in the hippocampus and other brain areas following repeated administration suggesting that the degradation of BMAA-associated proteins may be lower in neonatal brain than in the liver. Additional evidence is needed in support of a role for protein misincorporation in the neonatal hippocampus for long-term effects of BMAA. PMID:26498001

  11. Blood-brain barrier permeability to leucine-enkephalin, D-alanine2-D-leucine5-enkephalin and their N-terminal amino acid (tyrosine).

    PubMed

    Zlokovic, B V; Begley, D J; Chain-Eliash, D G

    1985-06-10

    The permeability of the blood-brain barrier to [tyrosyl-3,5-3H]enkephalin-(5-L-leucine) (abbreviated to Leu-Enk) and of its synthetic analogue D-alanine2-[tyrosyl-3,5-3H]enkephalin-(5-D-leucine) (abbreviated to D-Ala2-D-Leu5-Enk) was studied, in the adult rat, by means of Oldendorf's27 intracarotid injection technique. The brain uptake index (BUI) corrected for residual vascular radioactivity was about the same for both peptides, indicating a low extraction from the blood during a 5- or 15-s period of exposure to the peptides. Transport of Leu-Enk was not saturated by unlabelled Enk at a concentration as high as 5 mM but was completely abolished by 5mM tyrosine and by the inhibitor of aminopeptidase activity, bacitracin (2 mM). Also the typical L-transport system substrate, 2-aminobicyclo(2,2,1)heptane-2 carboxylic acid (BCH)9 at 10 mM concentration markedly reduced (by 80%) Leu-Enk uptake by the brain. In contrast, brain uptake of D-Ala2-D-Leu5-Enk was reduced only to about one-half of its control value by bacitracin or by 25% by BCH. Brain uptake for L-tyrosine was typically large and markedly inhibited by BCH but not inhibited by 5 mM unlabelled Leu-Enk. These results show that the measurable but low first-pass extractions for enkephalins are not representative of the uptake of these peptides into the brain, but rather reflect their extreme sensitivity to enzymatic degradation with a release of the N-terminal tyrosine residue. The results also suggest that small amounts of D-Ala2-D-Leu5-Enk might cross the blood-brain barrier in an intact form.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3891014

  12. Carnosine as a protective factor in diabetic nephropathy: association with a leucine repeat of the carnosinase gene CNDP1.

    PubMed

    Janssen, Bart; Hohenadel, Daniela; Brinkkoetter, Paul; Peters, Verena; Rind, Nina; Fischer, Christine; Rychlik, Ivan; Cerna, Marie; Romzova, Marianna; de Heer, Emile; Baelde, Hans; Bakker, Stephan J L; Zirie, Mahmoud; Rondeau, Eric; Mathieson, Peter; Saleem, Moin A; Meyer, Jochen; Köppel, Hannes; Sauerhoefer, Sibylle; Bartram, Claus R; Nawroth, Peter; Hammes, Hans-Peter; Yard, Benito A; Zschocke, Johannes; van der Woude, Fokko J

    2005-08-01

    The risk of diabetic nephropathy is partially genetically determined. Diabetic nephropathy is linked to a gene locus on chromosome 18q22.3-q23. We aimed to identify the causative gene on chromosome 18 and to study the mechanism by which the product of this gene could be involved in the development of diabetic nephropathy. DNA polymorphisms were determined in 135 case (diabetic nephropathy) and 107 control (diabetes without nephropathy) subjects. The effect of carnosine on the production of extracellular matrix components and transforming growth factor-beta (TGF-beta) after exposure to 5 and 25 mmol/l d-glucose was studied in cultured human podocytes and mesangial cells, respectively. A trinucleotide repeat in exon 2 of the CNDP1 gene, coding for a leucine repeat in the leader peptide of the carnosinase-1 precursor, was associated with nephropathy. The shortest allelic form (CNDP1 Mannheim) was more common in the absence of nephropathy (P = 0.0028, odds ratio 2.56 [95% CI 1.36-4.84]) and was associated with lower serum carnosinase levels. Carnosine inhibited the increased production of fibronectin and collagen type VI in podocytes and the increased production of TGF-beta in mesangial cells induced by 25 mmol/l glucose. Diabetic patients with the CNDP1 Mannheim variant are less susceptible for nephropathy. Carnosine protects against the adverse effects of high glucose levels on renal cells. PMID:16046297

  13. Prolonged leucine supplementation does not augment muscle mass or affect glycemic control in elderly type 2 diabetic men.

    PubMed

    Leenders, Marika; Verdijk, Lex B; van der Hoeven, Letty; van Kranenburg, Janneau; Hartgens, Fred; Wodzig, Will K W H; Saris, Wim H M; van Loon, Luc J C

    2011-06-01

    The loss of muscle mass with aging has been, at least partly, attributed to a blunted muscle protein synthetic response to food intake. Leucine coingestion has been reported to stimulate postprandial insulin release and augment postprandial muscle protein accretion. We assessed the clinical benefits of 6 mo of leucine supplementation in elderly, type 2 diabetes patients. Sixty elderly males with type 2 diabetes (age, 71 ± 1 y; BMI, 27.3 ± 0.4 kg/m(2)) were administered 2.5 g L-leucine (n = 30) or a placebo (n = 30) with each main meal during 6 mo of nutritional intervention (7.5 g/d leucine or placebo). Body composition, muscle fiber characteristics, muscle strength, glucose homeostasis, and basal plasma amino acid and lipid concentrations were assessed prior to, during, and after intervention. Lean tissue mass did not change or differ between groups and at 0, 3, and 6 mo were 61.9 ± 1.1, 62.2 ± 1.1, and 62.0 ± 1.0 kg, respectively, in the leucine group and 62.2 ± 1.3, 62.2 ± 1.3, and 62.2 ± 1.3 kg in the placebo group. There also were no changes in body fat percentage, muscle strength, and muscle fiber type characteristics. Blood glycosylated hemoglobin did not change or differ between groups and was 7.1 ± 0.1% in the leucine group and 7.2 ± 0.2% in the placebo group. Consistent with this, oral glucose insulin sensitivity and plasma lipid concentrations did not change or differ between groups. We conclude that prolonged leucine supplementation (7.5 g/d) does not modulate body composition, muscle mass, strength, glycemic control, and/or lipidemia in elderly, type 2 diabetes patients who habitually consume adequate dietary protein. PMID:21525248

  14. Optimized determination of angiotensin I-converting enzyme activity with hippuryl-L-histidyl-L-leucine as substrate.

    PubMed

    Schnaith, E; Beyrau, R; Bückner, B; Klein, R M; Rick, W

    1994-06-01

    The determination of the angiotensin I-converting enzyme activity (ACE, kininase II, peptidyldipeptide hydrolase, EC 3.4.15.1) is necessary to control the course and the treatment of sarcoidosis, as well as to monitor the therapeutic use of enzyme inhibitors such as captopril in hypertension or congestive heart failure. Numerous synthetic substrates are known with which to measure the enzyme activity. A discontinuous method using hippuryl-L-histidyl-L-leucine was tested and improved. The cleavage product, hippurate, reacts with cyanuric chloride to give a yellow complex which can be measured at 405 nm using a spectral line photometer. Enzyme activity, kinetic constants and activation energy are dependent on the chloride ion concentration. Optimal test concentrations are 1.1 mol/l potassium chloride and 3.0 mmol/l hippuryl-L-histidyl-L-leucine at pH 8.3. Higher substrate concentrations effect an inhibition of the enzyme reaction. A Michaelis constant of 0.9 mmol/l was found with serum as enzyme source. An activation energy of 57 kJ/mol was obtained from the relation between the logarithm of velocity of enzyme reaction and reciprocal value of absolute temperature. Furthermore, a linear dependence on chloride ion concentration was observed. The histogram of the enzyme activities in sera from 146 healthy volunteers shows a non-gaussian distribution. The reference interval at 25 degrees C is characterized by a median of 24 units/l with the 2.5th and the 97.5th percentiles at 13 units/l and 42 units/l, respectively. The corresponding values at 37 degrees C are 27 units/l and 86 units/l with a median of 48 units/l. No significant sex and age dependence could be found. A potent ACE inhibitor such as captopril leads to a rapid decrease of the enzyme activity within 60 min after oral administration. In the following hours, the enzyme activity slowly increases. PMID:7955411

  15. A novel mitochondrially-targeted apocynin derivative prevents hyposmia and loss of motor function in the leucine-rich repeat kinase 2 (LRRK2(R1441G)) transgenic mouse model of Parkinson's disease.

    PubMed

    Dranka, Brian P; Gifford, Alison; McAllister, Donna; Zielonka, Jacek; Joseph, Joy; O'Hara, Crystal L; Stucky, Cheryl L; Kanthasamy, Anumantha G; Kalyanaraman, Balaraman

    2014-11-01

    Recently, we demonstrated that dimeric apocynin prevented loss of motor function in the leucine-rich repeat kinase 2 (LRRK2(R1441G)) transgenic (tg) mouse (treated with 200mg/kg, three times per week) [B.P. Dranka et al., Neurosci. Lett. 549 (2013) 57-62]. Here we extend those studies by treating LRRK2(R1441G) mice with an orally-available, mitochondrially-targeted apocynin derivative. We hypothesized that the increased mitochondrial permeability of Mito-apocynin, due to the triphenylphosphonium moiety, would allow improvement of Parkinson's disease (PD) symptoms at lower doses than those required for diapocynin. Tests of motor coordination (pole test, Rotor-Rod) revealed a significant deficit in coordinated motor function in LRRK2(R1441G) mice by 15 months of age. Decreased performance on the pole test and Rotor-Rod in the LRRK2(R1441G) mice was prevented with Mito-apocynin treatment (3mg/kg, three times per week). Decreased olfactory function is an early indication of PD in human patients. LRRK2(R1441G) tg mice displayed deficits in sense of smell in both the hidden treat test, and a radial arm maze test. Interestingly, treatment with Mito-apocynin prevented this hyposmia, and animals retained normal ability to identify either a scented treat or a food pellet as well as wild type littermates. Together, these data demonstrate that the mitochondria-targeted apocynin analog is effective in preventing early PD-like symptoms in the LRRK2(R1441G) mouse model. PMID:25263790

  16. Neutron dose equivalent meter

    DOEpatents

    Olsher, Richard H.; Hsu, Hsiao-Hua; Casson, William H.; Vasilik, Dennis G.; Kleck, Jeffrey H.; Beverding, Anthony

    1996-01-01

    A neutron dose equivalent detector for measuring neutron dose capable of accurately responding to neutron energies according to published fluence to dose curves. The neutron dose equivalent meter has an inner sphere of polyethylene, with a middle shell overlying the inner sphere, the middle shell comprising RTV.RTM. silicone (organosiloxane) loaded with boron. An outer shell overlies the middle shell and comprises polyethylene loaded with tungsten. The neutron dose equivalent meter defines a channel through the outer shell, the middle shell, and the inner sphere for accepting a neutron counter tube. The outer shell is loaded with tungsten to provide neutron generation, increasing the neutron dose equivalent meter's response sensitivity above 8 MeV.

  17. A Membrane Leucine Heptad Contributes to Trafficking, Signaling, and Transformation by Latent Membrane Protein 1▿

    PubMed Central

    Lee, Jisook; Sugden, Bill

    2007-01-01

    Latent membrane protein 1 (LMP1) of Epstein Barr virus (EBV) is important for maintaining proliferation of EBV-infected B cells. LMP1, unlike its cellular counterpart, CD40, signals without a ligand and is largely internal to the plasma membrane. In order to understand how LMP1 initiates its ligand-independent signaling, we focused on a leucine heptad in LMP1's first membrane-spanning domain that was shown to be necessary for LMP1's signaling through NF-κB. LZ1EBV, a recombinant EBV genetically altered to express LZ1, a derivative of LMP1 in which a leucine heptad was replaced with alanines, transformed B cells with 56% of wild-type (wt) EBV's efficiency, demonstrating the importance of this heptad. To elucidate the mechanism by which this domain contributes to the functions of LMP1, the properties of the wt and LZ1 were compared in transfected cells. LZ1 failed to home to lipid rafts as efficiently as did wt LMP1. The distribution of tagged derivatives of LZ1 also differed from that of wt LMP1 in transfected cells. LZ1's defect in homing to lipid rafts and altered trafficking likely underlie the defect in transformation of LZ1EBV. While the third and fourth membrane-spanning domains of LMP1 foster its trafficking to the Golgi, the leucine heptad within the first membrane-spanning domain contributes to its trafficking, particularly to internal rafts. B cells that are successfully transformed by LZ1EBV have the same average number of viral genomes and the same fraction of cells with capped LZ1 at the cell surface but express 50% more of the LZ1 allele than wt infected cells. PMID:17581993

  18. Baicalin prevents Candida albicans infections via increasing its apoptosis rate

    SciTech Connect

    Yang, Shulong; Fu, Yingyuan Wu, Xiuzhen; Zhou, Zhixing; Xu, Jing; Zeng, Xiaoping; Kuang, Nanzhen; Zeng, Yurong

    2014-08-15

    Highlights: • Baicalin increases the ratio of the G0/G1 stages and C. albicans apoptosis. • Baicalin decreases the proliferation index of C. albicans. • Baicalin inhibits the biosynthesis of DNA, RNA and protein in C. albicans. • Baicalin depresses Succinate Dehydrogenase and Ca{sup 2+}–Mg{sup 2+} ATPase in C. albicans. • Baicalin increases the endocytic free Ca{sup 2+} concentration in C. albicans. - Abstract: Background: These experiments were employed to explore the mechanisms underlying baicalin action on Candida albicans. Methodology and principal findings: We detected the baicalin inhibition effects on three isotope-labeled precursors of {sup 3}H-UdR, {sup 3}H-TdR and {sup 3}H-leucine incorporation into C. albicans using the isotope incorporation technology. The activities of Succinate Dehydrogenase (SDH), cytochrome oxidase (CCO) and Ca{sup 2+}–Mg{sup 2+} ATPase, cytosolic Ca{sup 2+} concentration, the cell cycle and apoptosis, as well as the ultrastructure of C.albicans were also tested. We found that baicalin inhibited {sup 3}H-UdR, {sup 3}H-TdR and {sup 3}H-leucine incorporation into C.albicans (P < 0.005). The activities of the SDH and Ca{sup 2+}–Mg{sup 2+} ATPase of C.albicans in baicalin groups were lower than those in control group (P < 0.05). Ca{sup 2+} concentrations of C. albicans in baicalin groups were much higher than those in control group (P < 0.05). The ratio of C.albicans at the G0/G1 stage increased in baicalin groups in dose dependent manner (P < 0.01). There were a significant differences in the apoptosis rate of C.albicans between baicalin and control groups (P < 0.01). After 12–48 h incubation with baicalin (1 mg/ml), C. albicans shown to be markedly damaged under transmission electron micrographs. Innovation and significance: Baicalin can increase the apoptosis rate of C. albicans. These effects of Baicalin may involved in its inhibiting the activities of the SDH and Ca{sup 2+}–Mg{sup 2+} ATPase, increasing

  19. Long-term remission with rituximab in refractory leucine-rich glioma inactivated 1 antibody encephalitis.

    PubMed

    Brown, J William L; Martin, Peter J; Thorpe, John W; Michell, Andrew W; Coles, Alasdair J; Cox, Amanda L; Vincent, Angela; Zandi, Michael S

    2014-06-15

    Autoimmune encephalitis associated with antibodies to leucine-rich glioma inactivated 1 (LGI1) is recently described and there is a lack of detailed reports on the treatment of relapsing or refractory cases and long-term outcomes. Two case reports are presented. Both cases had faciobrachial dystonic seizures (FBDS) and received rituximab after relapsing or refractory disease. Both cases achieved sustained clinical remission of up to 15 and 56 months respectively. Rituximab use allowed withdrawal of corticosteroids and was well tolerated. Randomized clinical trials are needed in LGI1 encephalitis and other autoimmune encephalitides. PMID:24703099

  20. Structure-Based Design of Type II Inhibitors Applied to Maternal Embryonic Leucine Zipper Kinase.

    PubMed

    Johnson, Christopher N; Adelinet, Christophe; Berdini, Valerio; Beke, Lijs; Bonnet, Pascal; Brehmer, Dirk; Calo, Frederick; Coyle, Joseph E; Day, Phillip J; Frederickson, Martyn; Freyne, Eddy J E; Gilissen, Ron A H J; Hamlett, Christopher C F; Howard, Steven; Meerpoel, Lieven; Mevellec, Laurence; McMenamin, Rachel; Pasquier, Elisabeth; Patel, Sahil; Rees, David C; Linders, Joannes T M

    2015-01-01

    A novel Type II kinase inhibitor chemotype has been identified for maternal embryonic leucine zipper kinase (MELK) using structure-based ligand design. The strategy involved structural characterization of an induced DFG-out pocket by protein-ligand X-ray crystallography and incorporation of a slender linkage capable of bypassing a large gate-keeper residue, thus enabling design of molecules accessing both hinge and induced pocket regions. Optimization of an initial hit led to the identification of a low-nanomolar, cell-penetrant Type II inhibitor suitable for use as a chemical probe for MELK. PMID:25589926