The studies on the toxicity mechanism of environmentally hazardous natural (IAA) and synthetic (NAA) auxin--The experiments on model Arabidopsis thaliana and rat liver plasma membranes.

PubMed

Hąc-Wydro, Katarzyna; Flasiński, Michał

2015-06-01

This paper concerns the studies towards membrane-damage effect of two auxins: indole-3-acetic acid - IAA and 1-naphthaleneacetic acid - NAA on plant (Arabidopsis thaliana) and animal (rat liver) model membranes. The foregoing auxins are plant growth regulators widely used in agriculture to control the quality of the crop. However, their accumulation in the environment makes them hazardous for the living organisms. The aim of our investigations was to compare the effect of natural (IAA) vs. synthetic (NAA) auxin on the organization of plant and animal model membranes and find a possible correlation between membrane-disturbing effect of these compounds and their toxicity. The collected data evidenced that auxins cause destabilization of membranes, decrease their condensation and weakens interactions of molecules. The alterations in the morphology of model systems were also noticed. The foregoing effects of auxins are concentration-dependent and additionally NAA was found to act on animal vs. plant membranes more selectively than IAA. Interestingly, both IAA and NAA induce the strongest disordering in model lipid system at the concentration, which is frequently reported as toxic to animal and plants. Based on the above findings it was proposed that membrane-damage effect induced by IAA and NAA may be important from the point of view of the mechanism of toxicity of these compounds and cannot be ignored in further investigations in this area. Copyright © 2015 Elsevier B.V. All rights reserved.

Micropropagation and acclimatization of Stevia rebaudiana Bertoni.

PubMed

Chotikadachanarong, Kittisak; Dheeranupattana, Srisuluk

2013-09-01

Multiple shoot induction of Stevia rebaudiana Bertoni was studied by node explants that were cultured on solidified MS media and supplemented with 0, 1, 2, 3 and 4 mg L-1 kinetin for 4 weeks. The results showed the maximum amount of multiple shoot induction (9.31+/-4.17 shoots/explant) when cultured on MS media supplemented with 3 mg L-1 kinetin. In vitro shoots were rooted on solidified MS media supplemented with 0, 0.1, 0.5 and 2 mg L-1 Naphthaleneacetic Acid (NAA) for 4 weeks. The highest number of roots (11.18+/-1.34 roots/shoot) was detected on a concentration of 0.1 mg L-1 NAA while the high survival rate (80%) was obtained when the rooted plantlets were transferred to greenhouse conditions.

Micropropagation and assessment of genetic fidelity of Henckelia incana: an endemic and medicinal Gesneriad of South India.

PubMed

Prameela, J; Ramakrishnaiah, H; Krishna, V; Deepalakshmi, A P; Naveen Kumar, N; Radhika, R N

2015-07-01

Henckelia incana is an endemic medicinal plant used for the treatment of fever and skin allergy. In the present study shoot regeneration was evaluated on Murashige and Skoog's (MS) medium supplemented with auxins, Indole-3-acetic acid (IAA), Indole-3- butyric acid (IBA), 1-Naphthaleneacetic acid (NAA), 2, 4-Dichlorophenoxyacetic acid (2, 4-D) and cytokinins, 6-Benzylaminopurine (BAP) and Kinetin (Kn) at concentrations of 0.5, 1.0, 2.0, 3.0, 4.0 and 5.0 mgl(-1). MS medium with IBA (18.08), NAA (17.83) and IAA (17.58) at 0.5 mgl(-1) concentrations showed efficient regeneration. Regenerated shoots were rooted on half-strength MS medium with and without 0.5 mgl(-1) IBA or NAA. The plantlets were successfully hardened in rooting trays (peat, vermiculite and sand) and transferred to field mileu. The genetic fidelity of in vitro raised plants was assessed by using three different single primer amplification reaction (SPAR) markers namely random amplified polymorphic DNA (RAPD), inter-simple sequence repeat (ISSR) and direct amplification of mini-satellite DNA region (DAMD). The results consistently demonstrated true-to-true type propagation. This is the first report of in vitro propagation and establishment of true-to-true type genetic fidelity in H. incana.

In vitro callus culture of Heliotropium indicum Linn. for assessment of total phenolic and flavonoid content and antioxidant activity.

PubMed

Kumar, Muthusamy Senthil; Chaudhury, Shibani; Balachandran, Srinivasan

2014-12-01

The total phenolic and flavonoid content and percentage of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of callus and in vivo plant parts of Heliotropium indicum Linn. were estimated. Murashige and Skoog (MS) basal medium supplemented with α-naphthaleneacetic acid (NAA) 2.0 mg/l with benzyladenine (BA) 0.5 mg/l showed the highest amount of callus biomass (1.87 g/tube). The morphology of callus was significantly different according to the plant growth regulators and their concentrations used in the medium. The highest amount of total phenolic (21.70 mg gallic acid equivalent per gram (GAE/g)) and flavonoid (4.90 mg quercetin equivalent per gram (QE/g)) content and the maximum percentage (77.78 %) of radical scavenging activity were estimated in the extract of inflorescence. The synergistic effect of NAA (2.0 mg/l) and BA (0.5 mg/l) enhances the synthesis of total phenolic (9.20 mg GAE/g) and flavonoid (1.25 mg QE/g) content in the callus tissue. The callus produced by the same concentration shows 45.24 % of free radical scavenging activity. While comparing the various concentrations of NAA with 2,4-dichlorophenoxyacetic acid (2,4-D) for the production of callus biomass, total phenolic and flavonoid content and free radical scavenging activity, all the concentrations of NAA were found to be superior than those of 2,4-D.

Effects of natural and synthetic auxins on the gravitropic growth habit of roots in two auxin-resistant mutants of Arabidopsis, axr1 and axr4: evidence for defects in the auxin influx mechanism of axr4

NASA Technical Reports Server (NTRS)

Yamamoto, M.; Yamamoto, K. T.

1999-01-01

The partially agravitropic growth habit of roots of an auxin-resistant mutant of Arabidopsis thaliana, axr4, was restored by the addition of 30-300 nM 1-naphthaleneacetic acid (NAA) to the growth medium. Neither indole 3-acetic acid (IAA) nor 2,4-dichlorophenoxyacetic acid (2,4-D) showed such an effect. Growth of axr4 roots was resistant to IAA and 2,4-D, but not at all to NAA. The differential effects of the three auxins suggest that the defects of axr4 result from a lower auxin influx into its cells. The partially agravitropic growth habit of axr1 roots, which was less severe than that of axr4 roots, was only slightly affected by the three auxins in the growth medium at concentrations up to 300 nM; growth of axr1 roots was resistant to all three of the auxins. These results suggest that the lesion of axrl mutants is different from that of axr4.

A new genetic factor for root gravitropism in rice (Oryza sativa L.).

PubMed

Shi, Jiang-hua; Hao, Xi; Wu, Zhong-chang; Wu, Ping

2009-10-01

Root gravitropism is one of the important factors to determine root architecture. To understand the mechanism underlying root gravitropism, we isolated a rice (Xiushui63) mutant defective in root gravitropism, designated as gls1. Vertical sections of root caps revealed that gls1 mutant displayed normal distribution of amyloplast in the columella cells compared with the wild type. The gls1 mutant was less sensitive to 2,4-dichlorophenoxyacetic acid (2,4-D) and alpha-naphthaleneacetic acid (NAA) than the wild type. Genetic analysis indicated that the phenotype of gls1 mutant was caused by a single recessive mutation, which is mapped in a 255-kb region between RM16253 and CAPS1 on the short arm of chromosome 4.

Aminopropyl-modified mesoporous molecular sieves as efficient adsorbents for removal of auxins

NASA Astrophysics Data System (ADS)

Moritz, Michał; Geszke-Moritz, Małgorzata

2015-03-01

In the present study, mesoporous siliceous materials grafted with 3-aminopropyltriethoxysilane (APTES) were examined as sorbents for removal of chosen plant growth factors (auxins) such as 1-naphthaleneacetic acid (NAA), indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA). Four different types of mesoporous molecular sieves including SBA-15, PHTS, SBA-16 and MCF have been prepared via non-ionic surfactant-assisted soft templating method. Silica molecular sieves were thoroughly characterized by nitrogen adsorption-desorption analysis, powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FT-IR). The maximum adsorption capacity (Qmax) for NAA, IAA and IBA was in the range from 51.0 to 140.8 mg/g and from 4.3 to 7.3 mg/g for aminopropyl-modified adsorbents and pure silicas, respectively. The best adsorption performance was observed for IAA entrapment using both APTES-functionalized SBA-15 and MCF matrices (Qmax of 140.8 and 137.0 mg/g, respectively) which can be ascribed to their larger pore volumes and pore diameters. Moreover, these silicas were characterized by the highest adsorption efficiency exceeding 90% at low pollutant concentration. The experimental points for adsorption of plant growth factors onto aminopropyl-modified mesoporous molecular sieves fitted well to the Langmuir equation.

75 FR 37738 - 1-Naphthaleneacetic Acid; Time-Limited Tolerance, Technical Correction

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-30

...-Naphthaleneacetic Acid; Time-Limited Tolerance, Technical Correction AGENCY: Environmental Protection Agency (EPA..., ethylene oxide, fenvalerate, et al.; tolerance actions. Today's rule restores the time-limited tolerance...-3) establishing a time-limited tolerance for residues of 1-naphthaleneacetic acid ethyl ester in or...

Transcriptomics of shading-induced and NAA-induced abscission in apple (Malus domestica) reveals a shared pathway involving reduced photosynthesis, alterations in carbohydrate transport and signaling and hormone crosstalk

PubMed Central

2011-01-01

Background Naphthaleneacetic acid (NAA), a synthetic auxin analogue, is widely used as an effective thinner in apple orchards. When applied shortly after fruit set, some fruit abscise leading to improved fruit size and quality. However, the thinning results of NAA are inconsistent and difficult to predict, sometimes leading to excess fruit drop or insufficient thinning which are costly to growers. This unpredictability reflects our incomplete understanding of the mode of action of NAA in promoting fruit abscission. Results Here we compared NAA-induced fruit drop with that caused by shading via gene expression profiling performed on the fruit abscission zone (FAZ), sampled 1, 3, and 5 d after treatment. More than 700 genes with significant changes in transcript abundance were identified from NAA-treated FAZ. Combining results from both treatments, we found that genes associated with photosynthesis, cell cycle and membrane/cellular trafficking were downregulated. On the other hand, there was up-regulation of genes related to ABA, ethylene biosynthesis and signaling, cell wall degradation and programmed cell death. While the differentially expressed gene sets for NAA and shading treatments shared only 25% identity, NAA and shading showed substantial similarity with respect to the classes of genes identified. Specifically, photosynthesis, carbon utilization, ABA and ethylene pathways were affected in both NAA- and shading-induced young fruit abscission. Moreover, we found that NAA, similar to shading, directly interfered with leaf photosynthesis by repressing photosystem II (PSII) efficiency within 10 minutes of treatment, suggesting that NAA and shading induced some of the same early responses due to reduced photosynthesis, which concurred with changes in hormone signaling pathways and triggered fruit abscission. Conclusions This study provides an extensive transcriptome study and a good platform for further investigation of possible regulatory genes involved in the induction of young fruit abscission in apple, which will enable us to better understand the mechanism of fruit thinning and facilitate the selection of potential chemicals for the thinning programs in apple. PMID:22003957

Transcriptomics of shading-induced and NAA-induced abscission in apple (Malus domestica) reveals a shared pathway involving reduced photosynthesis, alterations in carbohydrate transport and signaling and hormone crosstalk.

PubMed

Zhu, Hong; Dardick, Chris D; Beers, Eric P; Callanhan, Ann M; Xia, Rui; Yuan, Rongcai

2011-10-17

Naphthaleneacetic acid (NAA), a synthetic auxin analogue, is widely used as an effective thinner in apple orchards. When applied shortly after fruit set, some fruit abscise leading to improved fruit size and quality. However, the thinning results of NAA are inconsistent and difficult to predict, sometimes leading to excess fruit drop or insufficient thinning which are costly to growers. This unpredictability reflects our incomplete understanding of the mode of action of NAA in promoting fruit abscission. Here we compared NAA-induced fruit drop with that caused by shading via gene expression profiling performed on the fruit abscission zone (FAZ), sampled 1, 3, and 5 d after treatment. More than 700 genes with significant changes in transcript abundance were identified from NAA-treated FAZ. Combining results from both treatments, we found that genes associated with photosynthesis, cell cycle and membrane/cellular trafficking were downregulated. On the other hand, there was up-regulation of genes related to ABA, ethylene biosynthesis and signaling, cell wall degradation and programmed cell death. While the differentially expressed gene sets for NAA and shading treatments shared only 25% identity, NAA and shading showed substantial similarity with respect to the classes of genes identified. Specifically, photosynthesis, carbon utilization, ABA and ethylene pathways were affected in both NAA- and shading-induced young fruit abscission. Moreover, we found that NAA, similar to shading, directly interfered with leaf photosynthesis by repressing photosystem II (PSII) efficiency within 10 minutes of treatment, suggesting that NAA and shading induced some of the same early responses due to reduced photosynthesis, which concurred with changes in hormone signaling pathways and triggered fruit abscission. This study provides an extensive transcriptome study and a good platform for further investigation of possible regulatory genes involved in the induction of young fruit abscission in apple, which will enable us to better understand the mechanism of fruit thinning and facilitate the selection of potential chemicals for the thinning programs in apple.

In vitro propagation and assessment of genetic stability of acclimated plantlets of Cornus alba L. using RAPD and ISSR markers.

PubMed

Ilczuk, Agnieszka; Jacygrad, Ewelina

2016-01-01

Cornus alba L. (white dogwood) is an important ornamental shrub having a wide range of applications such as reforestation programs and soil retention systems. The vegetative propagation of dogwood by cuttings may be slow, difficult, and cultivar dependent; therefore, an improved micropropagation method was developed. Nodal stem segments of C. alba cultivars 'Aurea' and 'Elegantissima' were cultured on media enriched with six different sources of macronutrients. Media were supplemented with either N 6 -benzyladenine (BA) or thidiazuron (TDZ) in combination with 1-naphthaleneacetic acid (NAA). Regardless of the cultivar, the best shoot proliferation was observed on Lloyd and McCown medium (woody plant medium (WPM)) at pH 6.2, containing 1.0 mg L -1 BA, 0.1 mg L -1 NAA, and 20-30 g L -1 sucrose. Rooting of regenerated shoots was achieved by an in vitro method when different concentrations of NAA or indole-3-butyric acid (IBA) were tested. Microcuttings were rooted for 8 wk on medium enriched with 0.25 mg L -1 NAA and potted into P9 containers in the greenhouse. The final survival rate of the plants after 20 wk was 80% for 'Aurea' and 90% for 'Elegantissima'. Genetic stability of the micropropagated plants was confirmed by using two DNA-based molecular marker techniques. A total of 30 random amplified polymorphic DNA (RAPD) and 20 inter-simple sequence repeat (ISSR) primers resulted in 197-199 and 184-187 distinct and reproducible band classes, respectively, in 'Aurea' and 'Elegantissima' plantlets. All of the RAPD and ISSR profiles were monomorphic and comparable with the mother plant.

In vitro propagation and cryopreservation of Aerides odorata Lour. (Orchidaceae).

PubMed

Hongthongkham, J; Bunnag, S

2014-05-01

An efficient method for in vitro propagation and cryopreservation of Aerides odorata was established. Leaf segments were cultured on New Dogashima (ND) mediums supplemented with various concentrations of Benzyladenine (BA) (0-5 mg L(-1)) combined with Naphthaleneacetic Acid (NAA) (0-2 mg L(-1)). The optimal treatment for inducing Protocorm-like Bodies (PLBs) from leaf segments was obtained from the combination of 1 or 3 mg L(-1) BA and 0.5 or 1 mg L(-1) NAA; whereas, the addition of BA or NAA alone induced shoot and/or root initiation rather than PLB or callus formation. Shoots rapidly developed on ND mediums containing 5 mg L(-1) BA. Cryopreservation of leaf segment-derived PLBs was successful using the encapsulation-dehydration method. The maximum survival percentage of Cryopreserved (Cryp) PLBs was achieved by encapsulating PLBs with 2% Na-alginate combined with 2 M glycerol and 0.4 M sucrose. The encapsulated PLBs were then precultured in 0.75 M sucrose for 24 h and dehydrated for 6 h before plunging into liquid nitrogen. Genetic stability of Cryp PLBs after regrowth was assessed by flow cytometry. The findings showed no different patterns of ploidy levels and morphology between Cryp and non-cryopreserved (Ncryp) control plantlets.

Plant regeneration from leaf protoplasts of Solanum torvum.

PubMed

Guri, A; Volokita, M; Sink, K C

1987-07-01

A protocol to obtain regenerated plants from protoplasts of Solanum torvum Sw a wild species of eggplant resistant to Verticillium wilt is reported. Leaf protoplasts were enzymatically isolated from six-week old seedlings grown in a controlled environment chamber. Protoplasts were plated on modified KM medium (0.4 M glucose)+(mg/l): 1.0 p-chlorophenoxyacetic acid (CPA)+1.0 naphthaleneacetic acid (NAA)+0.5 6-benzylaminopurine (BAP) and 0.02 abscisic acid (ABA). The protoplast density was 5×10(4) per ml with 5 ml placed in each of two quadrants in X-dishes (100×15 mm). The reservoir medium was modified KM+(mg/l): 0.1 NAA+0.5 BAP+0.1 M sucrose+0.1 M mannitol+0.6% washed agar+1% activated charcoal. Dishes were initially placed in the dark at 27°C. Protoplast division was initiated in 1-2 weeks and 4 weeks later p-calli were 1-3 mm. Plating efficiency was 11% when measured at 3 weeks. Six-week old p-calli were transferred individually onto Whatman No. 1 filter paper layered on modified KM (0.15 M sucrose)+mg/l: 2.0 indoleacetic acid (IAA)+2.0 zeatin+0.5% washed agar for 2 weeks. Subsequently, shoots occurred within 4 weeks at 70% efficiency on MS+30 g/l sucrose+2 mg/l zeatin. Shoots were rooted on half strength MS+10 g/l sucrose.

[Separation and determination of eight plant hormones by reversed-phase high performance liquid chromatography].

PubMed

Fang, N; Hou, S; Shao, X; He, Y; Zhao, G

1998-09-01

In this paper, reversed-phase high performance liquid chromatographic technique was used for the separation and determination of eight plant hormones. Methanol-water-acetic acid system was chosen as the mobile phase. The effects of different separation conditions, such as the methanol and acetic acid concentrations in mobile phase, on the retention behaviours of eight plant hormones in this system were studied. The general trends in retention behaviours could be correlated to the methanol concentration in mobile phase. The experimental results showed that the optimum separation was achieved with following gradient elution condition: 0-3 minutes, 70% (water percentage in mobile phase), 3-13 minutes, 70%-20%, 13-48 minutes, 20%. Benzene was added to be as the internal standard. Under this experimental condition, the eight plant hormones could be separated completely and detected quantitatively at 260 nm within 16 minutes. The calibration curves for the eight compounds gave linearity over a wide range. The correlation coefficients of each components were r(ZT) = 0.9971, r(GAs) = 0.9999, r(K) = 0.9997, r(BA) = 0.9995, r(IAA) = 0.9998, r(IPA) = 0.9982, r(IBA) = 0.9995 and r(NAA) = 0.9995. The method is rapid, simple and efficient. It is a suitable method for the accurate determination of gibberellic acid (GA) and alpha-naphthaleneacetic acid (alpha-NAA) in products for agricultural use.

Alkaloid production in Vernonia cinerea: Callus, cell suspension and root cultures.

PubMed

Maheshwari, Priti; Songara, Bharti; Kumar, Shailesh; Jain, Prachi; Srivastava, Kamini; Kumar, Anil

2007-08-01

Fast-growing callus, cell suspension and root cultures of Vernonia cinerea, a medicinal plant, were analyzed for the presence of alkaloids. Callus and root cultures were established from young leaf explants in Murashige and Skoog (MS) basal media supplemented with combinations of auxins and cytokinins, whereas cell suspension cultures were established from callus cultures. Maximum biomass of callus, cell suspension and root cultures were obtained in the medium supplemented with 1 mg/L alpha-naphthaleneacetic acid (NAA) and 5 mg/L benzylaminopurine (BA), 1.0 mg/L NAA and 0.1 mg/L BA and 1.5 mg/L NAA, respectively. The 5-week-old callus cultures resulted in maximum biomass and alkaloid contents (750 microg/g). Cell suspension growth and alkaloid contents were maximal in 20-day-old cultures and alkaloid contents were 1.15 mg/g. A 0.2-g sample of root tissue regenerated in semi-solid medium upon transfer to liquid MS medium containing 1.5 mg/L NAA regenerated a maximum increase in biomass of 6.3-fold over a period of 5 weeks. The highest root growth and alkaloid contents of 2 mg/g dry weight were obtained in 5-week-old cultures. Maximum alkaloid contents were obtained in root cultures in vitro compared to all others including the alkaloid content of in vivo obtained with aerial parts and roots (800 microg/g and 1.2 mg/g dry weight, respectively) of V. cinerea.

Micropropagation of Phalaenopsis and Doritaenopsis by culturing shoot tips of flower stalk buds.

PubMed

Tokuhara, K; Mii, M

1993-11-01

Green Protocorm-like Bodies (PLB) with high multiplication capacity were induced from shoot tips of flower stalk buds having 1 or 2 leaf primordia using New Dogashima Medium (NDM) containing 0.1 mg l(-1) α-naphthaleneacetic acid (NAA) and 1 mg 1(-1) 6-benzylaminopurine (BAP). These PLB were subcultured on the same medium. More than 10,000 PLBs were obtained from a few buds on a single flower stalk within one year. After transfer onto NDM containing no plant growth regulator (PGR), the PLB developed into plantlets. The micropropagation method formulated in this study was applicable to 12 different genotypes. These results suggest that the methodology could be used on a commercial scale for vegetative propagation of Phalaenopsis and Doritaenopsis.

Cytokinin profiles in ex vitro acclimatized Eucomis autumnalis plants pre-treated with smoke-derived karrikinolide.

PubMed

Aremu, Adeyemi O; Plačková, Lenka; Novák, Ondřej; Stirk, Wendy A; Doležal, Karel; Van Staden, Johannes

2016-01-01

The current evidence of regulatory effect of smoke-water (SW) and karrikinolide (KAR(1)) on the concentrations of endogenous cytokinins in plants partly explain the basis for their growth stimulatory activity. Karrikinolide (KAR1) which is derived from smoke-water (SW) is involved in some physiological aspects in the life-cycle of plants. This suggests a potential influence on the endogenous pool (quantity and quality) of phytohormones such as cytokinins (CKs). In the current study, the effect of SW (1:500; 1:1000; 1:1500 v/v dilutions) and KAR1 (10(-7); 10(-8); 10(-9) M) applied during micropropagation of Eucomis autumnalis subspecies autumnalis on the ex vitro growth and CKs after 4 months post-flask duration was evaluated. The interactions of SW and KAR(1) with benzyladenine (BA), α-naphthaleneacetic acid (NAA) or BA+NAA were also assessed. Plants treated with SW (1:500) and KAR1 (10(-8) M) demonstrated superior growth in terms of the rooting, leaf and bulb sizes and fresh biomass than the control and plants treated with BA and BA+NAA. However, plant growth was generally inhibited with either SW (1:500) or KAR1 (10(-8) M) and BA when compared to BA (alone) treatment. Relative to NAA treatment, the presence of KAR(1) (10(-7) M) with NAA significantly increased the leaf area and fresh biomass. Both SW and KAR1-treated plants accumulated more total CKs, mainly isoprenoid-type than the control and NAA-treated plants. The highest CK content was also accumulated in SW (1:500) with BA+NAA treatments. Similar stimulatory effects were observed with increasing concentrations of KAR(1) and BA. The current findings establish that SW and KAR1 exert significant influence on the endogenous CK pools. However, the better growth of plants treated with SW and KAR1 treatments was not exclusively related to the endogenous CKs.

Accurate Analysis and Evaluation of Acidic Plant Growth Regulators in Transgenic and Nontransgenic Edible Oils with Facile Microwave-Assisted Extraction-Derivatization.

PubMed

Liu, Mengge; Chen, Guang; Guo, Hailong; Fan, Baolei; Liu, Jianjun; Fu, Qiang; Li, Xiu; Lu, Xiaomin; Zhao, Xianen; Li, Guoliang; Sun, Zhiwei; Xia, Lian; Zhu, Shuyun; Yang, Daoshan; Cao, Ziping; Wang, Hua; Suo, Yourui; You, Jinmao

2015-09-16

Determination of plant growth regulators (PGRs) in a signal transduction system (STS) is significant for transgenic food safety, but may be challenged by poor accuracy and analyte instability. In this work, a microwave-assisted extraction-derivatization (MAED) method is developed for six acidic PGRs in oil samples, allowing an efficient (<1.5 h) and facile (one step) pretreatment. Accuracies are greatly improved, particularly for gibberellin A3 (-2.72 to -0.65%) as compared with those reported (-22 to -2%). Excellent selectivity and quite low detection limits (0.37-1.36 ng mL(-1)) are enabled by fluorescence detection-mass spectrum monitoring. Results show the significant differences in acidic PGRs between transgenic and nontransgenic oils, particularly 1-naphthaleneacetic acid (1-NAA), implying the PGRs induced variations of components and genes. This study provides, for the first time, an accurate and efficient determination for labile PGRs involved in STS and a promising concept for objectively evaluating the safety of transgenic foods.

Differential effects of NAA and 2,4-D in reducing floret abscission in cestrum (Cestrum elegans) cut flowers are associated with their differential activation of Aux/IAA homologous genes.

PubMed

Abebie, Bekele; Lers, Amnon; Philosoph-Hadas, Sonia; Goren, Raphael; Riov, Joseph; Meir, Shimon

2008-01-01

A previous study showed that the relative effectiveness of 2,4-dichlorophenoxyacetic acid (2,4-D) compared with that of 1-naphthaleneacetic acid (NAA) in reducing floret bud abscission in cestrum (Cestrum elegans) cut flowers was due to its acropetal transport. The aim of the present study was to examine if the differential effect of these auxins on floret abscission is reflected in the expression of Aux/IAA genes in the floret abscission zone (AZ). cDNAs were isolated by PCR-based cloning from the floret AZ of auxin-treated cut flowers. The expression patterns of the cDNAs in various tissues and the effect of indole-3-acetic acid (IAA), applied with or without cycloheximide, on their expression in the floret AZ were examined by northern blot analysis. The regulation of transcript accumulation in the floret AZ in response to NAA or 2,4-D was measured by real-time PCR during auxin pulsing of cut flowers and vase life, concomitantly with floret abscission. Six isolated cDNAs were identified to represent Aux/IAA homologous genes, designated as Cestrum elegans (Ce)-IAA1 to Ce-IAA6. Four Ce-IAA genes were characterized as early auxin-responsive genes (ARGs), and two (Ce-IAA1 and Ce-IAA5) as late ARGs. Only Ce-IAA5 was AZ-specific in floret buds. A temporal regulation of Ce-IAA transcript levels in the floret AZ was found, with 2,4-D inducing higher expression levels than NAA in floret buds. These Ce-IAA expression levels were negatively correlated with floret abscission. The differential transport characteristics of NAA and 2,4-D in cestrum cut flowers were reflected in differential activation of the Ce-IAA genes identified in the floret AZ. Therefore, Aux/IAA genes can be used as molecular markers to measure auxin activity, which reflects free auxin level in the AZ. Two of the identified genes, Ce-IAA1 and Ce-IAA5, may also have a regulatory role in abscission.

Enhanced production of phenolic acids in cell suspension culture of Salvia leriifolia Benth. using growth regulators and sucrose.

PubMed

Modarres, Masoomeh; Esmaeilzadeh Bahabadi, Sedigheh; Taghavizadeh Yazdi, Mohammad Ehsan

2018-04-01

Salvia leriifolia Benth. (Lamiaceae) is an endangered medicinal plant with hypoglycemic, anti-inflammatory and analgesic properties. Many of the beneficial effects of Salvia spp. are attributed to the phenolic compounds. In the present study, an efficient procedure has been developed for establishment of cell suspension culture of S. leriifolia as a strategy to obtain an in vitro phenolic acids producing cell line for the first time. The effect of growth regulators and various concentrations of sucrose have been analyzed, to optimize biomass growth and phenolic acids production. The callus used for this purpose was obtained from leaves of 15-day-old in vitro seedlings, on Murashige and Skoog (MS) basal medium supplemented with different hormone balances including benzylaminopurine (BAP) and indole butyric acid (IBA); 2,4-dichlorophenoxyacetic acid (2,4-D) and kinetin (KIN); naphthaleneacetic acid (NAA) and BAP. Modified MS medium supplemented with 5 mg/L BAP and 5 mg/L NAA was the optimal condition for callus formation with the highest induction rate (100%), the best callus growth and the highest phenolic acids content. No callus induction was observed in combinations of IBA and BAP. Cell suspension cultures were established by transferring 0.5 g of callus to 30 mL liquid MS medium supplemented with 5 mg/L BAP and 5 mg/L NAA. Dynamics of phenolic acids production has been investigated during the growth cycle of the suspension cultures. The maximum content of caffeic acid and salvianolic acid B were observed on the 15th day of the cultivation cycle while the highest amount of rosmarinic acid was observed on the first day. In response to various sucrose concentrations, cell cultures with 40 g/L sucrose not only produced the highest dry biomass but also the highest induction of caffeic acid and salvianolic acid B. The highest amount of rosmarinic acid was observed in media containing 50 g/L sucrose. These prepared cell suspension cultures provided a useful system for further enhanced production of phenolic acids at a large scale.

Auxin-Regulated Polypeptide Changes at Different Stages of Strawberry Fruit Development 1

PubMed Central

Veluthambi, K.; Poovaiah, B. W.

1984-01-01

The pattern of polypeptides at different stages of strawberry (Fragaria ananassa Duch. cv Ozark Beauty) fruit development was studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. An 81,000-dalton polypeptide appeared between 5 and 10 days after pollination. Polypeptides with molecular weights of 76,000 and 37,000 daltons were formed after 10 days. The control exerted by auxin in the stage-specific formation of polypeptides was investigated by stopping fruit growth after removing the achenes and reinitiating fruit growth by the application of a synthetic auxin, α-naphthaleneacetic acid (NAA). When the achenes were removed from the 5- and 10-day-old fruits, the fruits failed to grow, the 81,000 dalton polypeptide was not formed between 5 and 10 days, and the 76,000- and 37,000-dalton polypeptides were not formed between 10 and 20 days. Application of NAA to fruits deprived of auxin by removal of achenes resulted in the resumption of growth and also in the appearance of these polypeptides. Removal of achenes of the 5- or 10-day-old fruits and growing them without auxin resulted in the formation of 52,000- and 57,000-dalton polypeptides. These two polypeptides were not formed when NAA was applied to fruits after removal of achenes. Supply of NAA to auxin-deprived fruits 5 days after removal of achenes resulted in resumption of growth and also in the disappearance of these two polypeptides, pointing out their possible relation to the inhibition of fruit growth. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:16663624

Induction of tetraploids from petiole explants through colchicine treatments in Echinacea purpurea L.

PubMed

Nilanthi, Dahanayake; Chen, Xiao-Lu; Zhao, Fu-Cheng; Yang, Yue-Sheng; Wu, Hong

2009-01-01

Petiole explants were obtained from in vitro grown diploid (2x = 22) Echinacea purpurea plantlets. Shoots were regenerated by culturing the explants on MS basal medium containing 0.3 mg/L benzyladenine (BA), 0.01 mg/L naphthaleneacetic acid (NAA) and four concentrations (30, 60, 120, and 240 mg/L) of colchicine for 30 days, or 120 mg/L of colchicine for various durations (7, 14, 21, and 28 days). The regenerated shoots were induced to root on MS basal medium with 0.01 mg/L NAA, and then the root-tips of the regenerated shoots were sampled for count of chromosome number. It was found that a treatment duration of >7 days was necessary for induction of tetraploid (4x = 44) shoots, and treatment with 120 mg/L colchicine for 28 days was the most efficient for induction of tetraploids, yielding 23.5% of tetraploids among all the regenerated shoots. Chimeras were observed in almost all the treatments. However, the ratio of tetraploid to diploid cells in a chimeric plant was usually low. In comparison with diploid plants, tetraploid plants in vitro had larger stomata and thicker roots with more root branches, and had prominently shorter inflorescence stalk when mature.

Influence of Culture Medium Composition and Light Conditions on the Accumulation of Bioactive Compounds in Shoot Cultures of Scutellaria lateriflora L. (American Skullcap) Grown In Vitro.

PubMed

Kawka, Beata; Kwiecień, Inga; Ekiert, Halina

2017-12-01

Methanolic extracts from in vitro grown Scutellaria lateriflora shoots cultured on five Murashige and Skoog (MS) medium variants supplemented with different combinations of 6-benzylaminopurine (BAP) and α-naphthaleneacetic acid (NAA) under different light conditions (monochromatic light, white light and no light) were analysed by HPLC for three groups of metabolites: flavonoids (26 compounds), phenolic acids and their precursors (19+2) and phenylethanoid glycosides (2). The analyses revealed the presence of baicalein, baicalin, wogonin, wogonoside, 3,4-dihydroxyphenylacetic acid and verbascoside. There was clear evidence of the influence of plant growth regulators and light conditions on the accumulation of the analysed groups of secondary metabolites. The amounts of the compounds changed within a wide range-for the total flavonoid content, 30.2-fold (max. 1204.3 mg·100 g -1 dry weight (DW)); for 3,4-dihydroxyphenylacetic acid, 5.5-fold (max. 33.56 mg·100 g -1 DW); and for verbascoside, 1.5-fold (169.15 max. mg·100 g -1 DW). The best medium for the production of most of the compounds was the Murashige and Skoog variant with 1 mg l -1 BAP and 1 mg l -1 NAA. For verbascoside, the best 'productive' medium was the MS variant supplemented with 0.5 mg l -1 BAP and 2 mg l -1 NAA. The accumulation of the metabolites was stimulated to the greatest extent by blue light, under which the extracts were found to contain the highest total amount of flavonoids and the highest amounts of flavonoid glucuronides, baicalin and wogonoside, as well as of verbascoside. Their amounts were, respectively, 1.54-, 1.49-, 2.05- and 1.86-fold higher than under the control white light.

40 CFR 180.155 - 1-Naphthaleneacetic acid; tolerances for residues.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific... established for the combined residues of the plant growth regulator 1-naphthaleneacetic acid and its...

40 CFR 180.155 - 1-Naphthaleneacetic acid; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific... established for the combined residues of the plant growth regulator 1-naphthaleneacetic acid and its...

Studies on the tissue culture of Stevia rebaudiana and its components; (II). Induction of shoot primordia.

PubMed

Miyagawa, H; Fujioka, N; Kohda, H; Yamasaki, K; Taniguchi, K; Tanaka, R

1986-08-01

Shoot primordia, which were able to propagate vegetatively with a very high rate and to redifferentiate easily to new plants, were induced from shoot tips of Stevia rebaudiana Bertoni on Gamborg B5 medium containing 6-benzylaminopurine (BAP) and alpha-naphthaleneacetic acid (NAA) under light. The propagation of the shoot primordia of Stevia rebaudiana is rapid, and they are highly stable in chromosome number and karyotype. The shoot primordia can propagate at a high rate for a long time without differentiation. At any time, the shoot primordia readily developed into plantlets with shoots and roots within 2 or 3 weeks in static culture on B5 medium containing 0.02 mg/l BAP and 2% sucrose. The plantlets were transplanted to sterilized soil to grow to normal adult plants.

Simultaneous determination of four plant hormones in bananas by molecularly imprinted solid-phase extraction coupled with high performance liquid chromatography.

PubMed

Yan, Hongyuan; Wang, Fang; Han, Dandan; Yang, Gengliang

2012-06-21

A highly selective molecularly imprinted solid-phase extraction (MISPE) combined with liquid chromatography-ultraviolet detection was developed for the simultaneous isolation and determination of four plant hormones including indole-3-acetic acid (IAA), indole-3-propionic acid (IPA), indole-3-butyric acid (IBA) and 1-naphthaleneacetic acid (NAA) in banana samples. The new molecularly imprinted microspheres (MIMs) prepared by aqueous suspension polymerization using 3-hydroxy-2-naphthoic acid and 1-methylpiperazine as mimic templates performed with high selectivity and affinity for the four plant hormones, and applied as selective sorbents of solid-phase extraction could effectively eliminate the interferences of the banana matrix. Good linearity was obtained in a range of 0.04-4.00 μg g(-1) and the recoveries of the four plant hormones at three spiked levels ranged from 78.5 to 107.7% with the relative standard deviations (RSD) of less than 4.6%. The developed MISPE-HPLC protocol obviously improved the selectivity and eliminated the effect of template leakage on quantitative analysis, and could be applied for the determination of plant hormones in complicated biological samples.

Micropropagation and subsequent enrichment of carotenoids, fatty acids and tocopherol contents in Sedum dasyphyllum L

NASA Astrophysics Data System (ADS)

Park, Han Yong; Saini, Ramesh Kumar; Gopal, Judy; Keum, Young-Soo; Kim, Doo Hwan; Lee, Onew; Sivanesan, Iyyakkannu

2017-10-01

A promising micropropagation protocol has been systematically established and demonstrated for the enhanced production of carotenoids, tocopherol and fatty acids in shoot tissues of Sedum dasyphyllum. Shoot tip explants were grown on Murashige and Skoog (MS) medium. Different concentrations of N6-benzyladenine (BA) or thidiazuron (TDZ) alone or in combination with α-naphthaleneacetic acid (NAA) were tested in order to stimulate multiple shoot production. Ideal shoot induction (100%) and maximized shoot numbers (36.4) were obtained on explants cultured on media incorporated with 2 µM BA and 1 µM NAA combinations. The in vitro-developed shoots rooted best on half-strength MS media incorporated with 2 µM indole 3-butyric acid. Plantlets were effectively acclimatized in the greenhouse with 100% survival rate. The composition and contents of bioactive compounds such as carotenoids, tocopherol and fatty acids in shoot tissues of S. dasyphyllum were investigated using HPLC and GC-MS. The most abundant carotenoid in the shoot tissue was all-E-lutein (40.3-70.5 µg g-1 FW) followed by 9'-Z-neoxanthin (5.3-9.9 µg g-1 FW), all-E-violaxanthin (4.4-8.2 µg g-1 FW), and all-E-β-carotene (1.6-3.6 µg g-1 FW). The α-tocopherol contents of in vitro-raised shoots was 6.5-fold higher than shoots of greenhouse-grown plants. The primary fatty acids found in shoot tissues were α-linolenic acid (32.0-39.3%), linoleic acid (27.4-38.2%), palmitic acid (13.3-15.5%) and stearic acid (5.2-12.2%). In all, summarizing the findings, the micropropagated S. dasyphyllum showed significant enrichment of valuable bioactive carotenoids (92.3 µg g-1 FW), tocopherols (14.6 µg g-1 FW) and α-linolenic acid (39.3%) compared to their greenhouse counterparts. The protocol demonstrated here could be applied for the mass propagation and production of enhanced bioactive compounds from S. dasyphyllum with credibility.

Effects of light and growth regulators on adventitious bud formation in horseradish (Armoracia rusticana).

PubMed

Kamada, H; Tachikawa, Y; Saitou, T; Harada, H

1995-07-01

To clarify that the presence of Ri T-DNA genes are not prerequisite for the light-induced bud formation in horseradish (Armoracia rusticana) hairy roots, leaf and root segments of nontransformed horseradish plants were used as explants. Bud formation from nontransformed tissues was observed in hormone-free medium under 16 h daylight conditions, but not under continuous darkness. To investigate the effects of growth regulators on bud formation, leaf and root explants were treated with auxin (1-naphthaleneacetic acid; NAA) and / or cytokinin (6-benzyl-aminopurine; BA). The most effective treatment in the dark to stimulate bud formation was BA at 1 mg·1(-1). These results show that adventitious bud formation in horseradish can be induced by light and growth regulators, and especially cytokinin, may be involved in bud formation, irrespective of whether the tissues were transformed with Ri T-DNA.

Induction of Tetraploids from Petiole Explants through Colchicine Treatments in Echinacea purpurea L.

PubMed Central

Nilanthi, Dahanayake; Chen, Xiao-Lu; Zhao, Fu-Cheng; Yang, Yue-Sheng; Wu, Hong

2009-01-01

Petiole explants were obtained from in vitro grown diploid (2x = 22) Echinacea purpurea plantlets. Shoots were regenerated by culturing the explants on MS basal medium containing 0.3 mg/L benzyladenine (BA), 0.01 mg/L naphthaleneacetic acid (NAA) and four concentrations (30, 60, 120, and 240 mg/L) of colchicine for 30 days, or 120 mg/L of colchicine for various durations (7, 14, 21, and 28 days). The regenerated shoots were induced to root on MS basal medium with 0.01 mg/L NAA, and then the root-tips of the regenerated shoots were sampled for count of chromosome number. It was found that a treatment duration of >7 days was necessary for induction of tetraploid (4x = 44) shoots, and treatment with 120 mg/L colchicine for 28 days was the most efficient for induction of tetraploids, yielding 23.5% of tetraploids among all the regenerated shoots. Chimeras were observed in almost all the treatments. However, the ratio of tetraploid to diploid cells in a chimeric plant was usually low. In comparison with diploid plants, tetraploid plants in vitro had larger stomata and thicker roots with more root branches, and had prominently shorter inflorescence stalk when mature. PMID:19696915

In vitro propagation via organogenesis and synthetic seeds of Urginea altissima (L.f.) Baker: a threatened medicinal plant.

PubMed

Baskaran, Ponnusamy; Kumari, Aloka; Van Staden, Johannes

2018-01-01

Efficient in vitro propagation systems via organogenesis and synthetic seeds were developed for the first time for conservation and commercial propagation from leaf or longitudinal thin cell layer (lTCL) leaf or shoot-tip explants of Urginea altissima . Various plant growth regulators and phloroglucinol were used in semi-solid and liquid Murashige and Skoog (MS) medium to establish multiplication of shoots and roots for in vitro regeneration. Of the various treatments, the highest number of shoots (17.4 per lTCL leaf explant) was obtained on liquid MS medium supplemented with 10 µM meta -Topolin ( m T) and 2 µM benzyladenine followed by transferal to semi-solid MS media. The shoot tips were encapsulated with liquid MS medium plus 3% (w/v) sodium alginate and 100 mM calcium chloride. Adventitious shoot regeneration (91.0%; 12.6 shoots per synthetic seed) of synthetic seeds was achieved on semi-solid MS medium supplemented with 10 µM m T and 2 µM naphthaleneacetic acid (NAA) after 15 days of storage in darkness at 25 ± 2 °C. Regenerated shoots rooted (9.8 roots per shoot; 6.5 cm long) efficiently when transferred to 5 µM indole-3-butyric acid and 2.5 µM NAA. All the plantlets were successfully acclimatized (100%) in a vermiculite:soil (1:1 v/v) mixture in the greenhouse.

Auxins differentially regulate root system architecture and cell cycle protein levels in maize seedlings.

PubMed

Martínez-de la Cruz, Enrique; García-Ramírez, Elpidio; Vázquez-Ramos, Jorge M; Reyes de la Cruz, Homero; López-Bucio, José

2015-03-15

Maize (Zea mays) root system architecture has a complex organization, with adventitious and lateral roots determining its overall absorptive capacity. To generate basic information about the earlier stages of root development, we compared the post-embryonic growth of maize seedlings germinated in water-embedded cotton beds with that of plants obtained from embryonic axes cultivated in liquid medium. In addition, the effect of four different auxins, namely indole-3-acetic acid (IAA), 1-naphthaleneacetic acid (NAA), indole-3-butyric acid (IBA) and 2,4-dichlorophenoxyacetic acid (2,4-D) on root architecture and levels of the heat shock protein HSP101 and the cell cycle proteins CKS1, CYCA1 and CDKA1 were analyzed. Our data show that during the first days after germination, maize seedlings develop several root types with a simultaneous and/or continuous growth. The post-embryonic root development started with the formation of the primary root (PR) and seminal scutellar roots (SSR) and then continued with the formation of adventitious crown roots (CR), brace roots (BR) and lateral roots (LR). Auxins affected root architecture in a dose-response fashion; whereas NAA and IBA mostly stimulated crown root formation, 2,4-D showed a strong repressing effect on growth. The levels of HSP101, CKS1, CYCA1 and CDKA in root and leaf tissues were differentially affected by auxins and interestingly, HSP101 registered an auxin-inducible and root specific expression pattern. Taken together, our results show the timing of early branching patterns of maize and indicate that auxins regulate root development likely through modulation of the HSP101 and cell cycle proteins. Copyright © 2014 Elsevier GmbH. All rights reserved.

Separation of plant hormones from biofertilizer by capillary electrophoresis using a capillary coated dynamically with polycationic polymers.

PubMed

Jiang, Ting-Fu; Lv, Zhi-Hua; Wang, Yuan-Hong; Yue, Mei-E

2006-06-01

A new, simple and rapid capillary electrophoresis (CE) method, using hexadimethrine bromide (HDB) as electroosmotic flow (EOF) modifier, was developed for the identification and quantitative determination of four plant hormones, including gibberellin A3 (GA3), indole-3-acetic acid (IAA), alpha-naphthaleneacetic acid (NAA) and 4-chlorophenoxyacetic acid (4-CA). The optimum separation was achieved with 20 mM borate buffer at pH 10.00 containing 0.005% (w/v) of HDB. The applied voltage was -25 kV and the capillary temperature was kept constant at 25 degrees C. Salicylic acid was used as internal standard for quantification. The calibration dependencies exhibited good linearity within the ratios of the concentrations of standard samples and internal standard and the ratios of the peak areas of samples and internal standard. The correlation coefficients were from 0.9952 to 0.9997. The relative standard deviations of migration times and peak areas were < 1.93 and 6.84%, respectively. The effects of buffer pH, the concentration of HDB and the voltage on the resolution were studied systematically. By this method, the contents of plant hormone in biofertilizer were successfully determined within 7 min, with satisfactory repeatability and recovery.

Simultaneous analysis of different classes of phytohormones in coconut (Cocos nucifera L.) water using high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry after solid-phase extraction.

PubMed

Ma, Zhen; Ge, Liya; Lee, Anna S Y; Yong, Jean Wan Hong; Tan, Swee Ngin; Ong, Eng Shi

2008-03-10

Coconut (Cocos nucifera L.) water, which contains many uncharacterized phytohormones is extensively used as a growth promoting supplement in plant tissue culture. In this paper, a high-performance liquid chromatography (HPLC) method was developed for the simultaneous determination of various classes phytohormones, including indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), abscisic acid (ABA), gibberellic acid (GA), zeatin (Z), N(6)-benzyladenine (BA), alpha-naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D) in young coconut water (CW). The analysis was carried out using a reverse-phase HPLC gradient elution, with an aqueous mobile phase (containing 0.1% formic acid, pH adjusted to 3.2 with triethylamine (TEA)) modified by methanol, and solute detection made at 265 nm wavelength. The method was validated for specificity, quantification, accuracy and precision. After preconcentration of putative endogenous phytohormones in CW using C(18) solid-phase extraction (SPE) cartridges, the HPLC method was able to screen for putative endogenous phytohormones present in CW. Finally, the identities of the putative phytohormones present in CW were further confirmed using independent liquid chromatography-tandem mass spectrometry (LC-MS/MS) equipped with an electrospray ionization (ESI) interface.

Hormonal regulation of floret closure of rice (Oryza sativa)

PubMed Central

Huang, Youming; Zeng, Xiaochun

2018-01-01

Plant hormones play important roles in regulating every aspect of growth, development, and metabolism of plants. We are interested in understanding hormonal regulation of floret opening and closure in plants. This is a particularly important problem for hybrid rice because regulation of flowering time is vitally important in hybrid rice seed production. However, little was known about the effects of plant hormones on rice flowering. We have shown that jasmonate and methyl jasmonate play significant roles in promoting rice floret opening. In this study, we investigated the effects of auxins including indole-3-acidic acid (IAA), indole-3-butyric acid (IBA), 1-naphthalene-acetic acid (NAA), 2,4-dichlorophenoxy acetic acid (2,4-D) and 3,6-dichloro-2-methoxybenzoic acid (DIC) and abscisic acid (ABA) on floret closure of four fertile and three sterile varieties of rice. The results from field studies in three growing seasons in 2013–2015 showed that the percentages of closed florets were significantly lower in plants treated with IAA, IBA, 2,4-D, DIC and NAA and that the durations of floret opening were significantly longer in plants treated with the same auxins. The auxins exhibited time- and concentration-dependant effects on floret closure. ABA displayed opposite effects of auxins because it increased the percentages of floret closure and decreased the length of floret opening of rice varieties. The degree of auxin-inhibiting and ABA-promoting effects on floret closure was varied somewhat but not significantly different among the rice varieties. Endogenous IAA levels were the highest in florets collected shortly before opening followed by a sharp decline in florets with maximal angles of opening and a significant jump of IAA levels shortly after floret closure in both fertile and sterile rice plants. ABA levels showed an opposite trend in the same samples. Our results showed that auxins delayed but ABA promoted the closure of rice floret regardless of the varieties. PMID:29879200

New auxin analogs with growth-promoting effects in intact plants reveal a chemical strategy to improve hormone delivery.

PubMed

Savaldi-Goldstein, Sigal; Baiga, Thomas J; Pojer, Florence; Dabi, Tsegeye; Butterfield, Cristina; Parry, Geraint; Santner, Aaron; Dharmasiri, Nihal; Tao, Yi; Estelle, Mark; Noel, Joseph P; Chory, Joanne

2008-09-30

Plant growth depends on the integration of environmental cues and phytohormone-signaling pathways. During seedling emergence, elongation of the embryonic stem (hypocotyl) serves as a readout for light and hormone-dependent responses. We screened 10,000 chemicals provided exogenously to light-grown seedlings and identified 100 compounds that promote hypocotyl elongation. Notably, one subset of these chemicals shares structural characteristics with the synthetic auxins, 2,4-dichlorophenoxyacetic acid (2,4-D), and 1-naphthaleneacetic acid (1-NAA); however, traditional auxins (e.g., indole-3-acetic acid [IAA], 2,4-D, 1-NAA) have no effect on hypocotyl elongation. We show that the new compounds act as "proauxins" akin to prodrugs. Our data suggest that these compounds diffuse efficiently to the hypocotyls, where they undergo cleavage at varying rates, releasing functional auxins. To investigate this principle, we applied a masking strategy and designed a pro-2,4-D. Unlike 2,4-D alone, this pro-2,4-D enhanced hypocotyl elongation. We further demonstrated the utility of the proauxins by characterizing auxin responses in light-grown hypocotyls of several auxin receptor mutants. These new compounds thus provide experimental access to a tissue previously inaccessible to exogenous application of auxins. Our studies exemplify the combined power of chemical genetics and biochemical analyses for discovering and refining prohormone analogs with selective activity in specific plant tissues. In addition to the utility of these compounds for addressing questions related to auxin and light-signaling interactions, one can envision using these simple principles to study other plant hormone and small molecule responses in temporally and spatially controlled ways.

New auxin analogs with growth-promoting effects in intact plants reveal a chemical strategy to improve hormone delivery

PubMed Central

Savaldi-Goldstein, Sigal; Baiga, Thomas J.; Pojer, Florence; Dabi, Tsegeye; Butterfield, Cristina; Parry, Geraint; Santner, Aaron; Dharmasiri, Nihal; Tao, Yi; Estelle, Mark; Noel, Joseph P.; Chory, Joanne

2008-01-01

Plant growth depends on the integration of environmental cues and phytohormone-signaling pathways. During seedling emergence, elongation of the embryonic stem (hypocotyl) serves as a readout for light and hormone-dependent responses. We screened 10,000 chemicals provided exogenously to light-grown seedlings and identified 100 compounds that promote hypocotyl elongation. Notably, one subset of these chemicals shares structural characteristics with the synthetic auxins, 2,4-dichlorophenoxyacetic acid (2,4-D), and 1-naphthaleneacetic acid (1-NAA); however, traditional auxins (e.g., indole-3-acetic acid [IAA], 2,4-D, 1-NAA) have no effect on hypocotyl elongation. We show that the new compounds act as “proauxins” akin to prodrugs. Our data suggest that these compounds diffuse efficiently to the hypocotyls, where they undergo cleavage at varying rates, releasing functional auxins. To investigate this principle, we applied a masking strategy and designed a pro-2,4-D. Unlike 2,4-D alone, this pro-2,4-D enhanced hypocotyl elongation. We further demonstrated the utility of the proauxins by characterizing auxin responses in light-grown hypocotyls of several auxin receptor mutants. These new compounds thus provide experimental access to a tissue previously inaccessible to exogenous application of auxins. Our studies exemplify the combined power of chemical genetics and biochemical analyses for discovering and refining prohormone analogs with selective activity in specific plant tissues. In addition to the utility of these compounds for addressing questions related to auxin and light-signaling interactions, one can envision using these simple principles to study other plant hormone and small molecule responses in temporally and spatially controlled ways. PMID:18818305

Micropropagation and Subsequent Enrichment of Carotenoids, Fatty Acids, and Tocopherol Contents in Sedum dasyphyllum L

PubMed Central

Park, Han Yong; Saini, Ramesh Kumar; Gopal, Judy; Keum, Young-Soo; Kim, Doo Hwan; Lee, Onew; Sivanesan, Iyyakkannu

2017-01-01

A promising micropropagation protocol has been systematically established and demonstrated for the enhanced production of carotenoids, tocopherol and fatty acids in shoot tissues of Sedum dasyphyllum. Shoot tip explants were grown on Murashige and Skoog (MS) medium. Different concentrations of N6-benzyladenine (BA) or thidiazuron (TDZ) alone or in combination with α-naphthaleneacetic acid (NAA) were tested in order to stimulate multiple shoot production. Ideal shoot induction (100%) and maximized shoot numbers (36.4) were obtained on explants cultured on media incorporated with 2 μM BA and 1 μM NAA combinations. The in vitro-developed shoots rooted best on half-strength MS media incorporated with 2 μM indole 3-butyric acid. Plantlets were effectively acclimatized in the greenhouse with 100% survival rate. The composition and contents of bioactive compounds such as carotenoids, tocopherol and fatty acids in shoot tissues of S. dasyphyllum were investigated using HPLC and GC-MS. The most abundant carotenoid in the shoot tissue was all-E-lutein (40.3–70.5 μg g−1 FW) followed by 9′-Z-neoxanthin (5.3–9.9 μg g−1 FW), all-E-violaxanthin (4.4–8.2 μg g−1 FW), and all-E-β-carotene (1.6–3.6 μg g−1 FW). The α-tocopherol contents of in vitro-raised shoots was 6.5-fold higher than shoots of greenhouse-grown plants. The primary fatty acids found in shoot tissues were α-linolenic acid (32.0–39.3%), linoleic acid (27.4–38.2%), palmitic acid (13.3–15.5%), and stearic acid (5.2–12.2%). In all, summarizing the findings, the micropropagated S. dasyphyllum showed significant enrichment of valuable bioactive carotenoids (92.3 μg g−1 FW), tocopherols (14.6 μg g−1 FW), and α-linolenic acid (39.3%) compared to their greenhouse counterparts. The protocol demonstrated here could be applied for the mass propagation and production of enhanced bioactive compounds from S. dasyphyllum with credibility. PMID:29062834

Micropropagation and Subsequent Enrichment of Carotenoids, Fatty Acids, and Tocopherol Contents in Sedum dasyphyllum L.

PubMed

Park, Han Yong; Saini, Ramesh Kumar; Gopal, Judy; Keum, Young-Soo; Kim, Doo Hwan; Lee, Onew; Sivanesan, Iyyakkannu

2017-01-01

A promising micropropagation protocol has been systematically established and demonstrated for the enhanced production of carotenoids, tocopherol and fatty acids in shoot tissues of Sedum dasyphyllum . Shoot tip explants were grown on Murashige and Skoog (MS) medium. Different concentrations of N 6 -benzyladenine (BA) or thidiazuron (TDZ) alone or in combination with α-naphthaleneacetic acid (NAA) were tested in order to stimulate multiple shoot production. Ideal shoot induction (100%) and maximized shoot numbers (36.4) were obtained on explants cultured on media incorporated with 2 μM BA and 1 μM NAA combinations. The in vitro -developed shoots rooted best on half-strength MS media incorporated with 2 μM indole 3-butyric acid. Plantlets were effectively acclimatized in the greenhouse with 100% survival rate. The composition and contents of bioactive compounds such as carotenoids, tocopherol and fatty acids in shoot tissues of S. dasyphyllum were investigated using HPLC and GC-MS. The most abundant carotenoid in the shoot tissue was all- E -lutein (40.3-70.5 μg g -1 FW) followed by 9'- Z -neoxanthin (5.3-9.9 μg g -1 FW), all- E -violaxanthin (4.4-8.2 μg g -1 FW), and all- E -β-carotene (1.6-3.6 μg g -1 FW). The α-tocopherol contents of in vitro -raised shoots was 6.5-fold higher than shoots of greenhouse-grown plants. The primary fatty acids found in shoot tissues were α-linolenic acid (32.0-39.3%), linoleic acid (27.4-38.2%), palmitic acid (13.3-15.5%), and stearic acid (5.2-12.2%). In all, summarizing the findings, the micropropagated S. dasyphyllum showed significant enrichment of valuable bioactive carotenoids (92.3 μg g -1 FW), tocopherols (14.6 μg g -1 FW), and α-linolenic acid (39.3%) compared to their greenhouse counterparts. The protocol demonstrated here could be applied for the mass propagation and production of enhanced bioactive compounds from S. dasyphyllum with credibility.

The impact of auxins used in assisted phytoextraction of metals from the contaminated environment on the alterations caused by lead(II) ions in the organization of model lipid membranes.

PubMed

Hąc-Wydro, Katarzyna; Sroka, Aleksandra; Jabłońska, Klaudia

2016-07-01

Auxins are successfully used to improve phytoextraction efficiency of metal ions from the contaminated environment, however, the mechanism of their activity in this field is not explained. Auxins are known to exert various biochemical alterations in the plant membranes and cells, but their activity involves also direct interactions with lipids leading to changes in membrane organization. Following the suggestion that the auxins-induced modifications in membrane properties alleviate toxic effect of metal ions in this paper we have undertaken the comparative studies on the effect of metal ions and metal ions/auxins mixtures on model membrane systems. The experiments were done on lipid monolayers differing in their composition spread on water subphase and on Pb(2+), Indole-3-acetic acid (IAA), 1-Naphthaleneacetic acid (NAA) and Pb(2+)/IAA and Pb(2+)/NAA water solutions. The analysis of the collected data suggests that metal ions and auxins can change fluidity of the lipid systems and weaken the interactions between monolayer components. This manifested in the increase of the mean area per molecule and the excess area per molecule values for the films on Pb(2+), auxins as well as Pb(2+)/auxin solutions as compared to the values on pure water subphase. However, the presence of auxin in the mixture with lead(II) ions makes the alterations induced by sole metal ions weaker. This effect was more pronounced for the membranes of a higher packing. Thus it was proposed that auxins may enhance phytoextraction of metal ions by weakening their destabilizing effect on membrane. Copyright © 2016 Elsevier B.V. All rights reserved.

Efficient plant regeneration through somatic embryogenesis from callus cultures of Oncidium (Orchidaceae).

PubMed

Chen, J -T.; Chang, W -C.

2000-12-07

An efficient method was established for high frequency somatic embryogenesis and plant regeneration from callus cultures of a hybrid of sympodial orchid (Oncidium 'Gower Ramsey'). Compact and yellow-white embryogenic calli formed from root tips and cut ends of stem and leaf segments on 1/2 MS [11] basal medium supplemented with 1-phenyl-3-(1,2,3-thiadiazol-5-yl)-urea (TDZ, 0.1-3 mg/l), 2,4-dichlorophenoxyacetic acid (2,4-D, 3-10 mg/l) and peptone (1 g/l) for 4-7 weeks. Embryogenic callus was maintained by subculture on the same medium for callus induction and proliferated 2-4 times (fresh weight) in 1 month. Initiation of somatic embryogenesis and development up to the protocorm-like-bodies (PLBs) from callus cultures was achieved on hormone-free basal medium. Regenerants were recovered from somatic embryos (SEs) after transfer to the same medium and showed normal development. The optimized protocol required about 12-14 weeks from the initiation of callus to the plantlet formation. Generally, the frequency of embryo formation of root-derived callus was higher than stem- and leaf-derived calli. Combinations of naphthaleneacetic acid (NAA) and TDZ significantly promoted embryo formation from callus cultures. The high-frequency (93.8%) somatic embryogenesis and an average of 29.1 SEs per callus (3x3 mm(2)) was found in root-derived callus on a basal medium supplemented with 0.1 mg/l NAA and 3 mg/l TDZ. Almost all the SEs converted and the plantlets grew well with an almost 100% survival rate when potted in sphagnum moss and acclimatized in the greenhouse.

Volatile organic compounds obtained by in vitro callus cultivation of Plectranthus ornatus Codd. (Lamiaceae).

PubMed

Passinho-Soares, Helna C; Meira, Paloma R; David, Juceni P; Mesquita, Paulo R R; do Vale, Ademir E; de M Rodrigues, Frederico; de P Pereira, Pedro A; de Santana, José Raniere F; de Oliveira, Fabio S; de Andrade, Jailson B; David, Jorge M

2013-08-26

Plectranthus spp (Lamiaceae) are plants of economic importance because they are sources of aromatic essential oils and are also cultivated and several species of this genus are used as folk medicines. This paper describes the effects of different concentrations of the 2,4-dichlorophenoxyacetic acid (2,4-D) and 1-naphthaleneacetic acid (NAA) on the induction of callus from nodal segments of Plectranthus ornatus Codd and in the production of volatile organic compounds (monoterpenes and sesquiterpenes). The 20 and 40 day calli were subjected to solid phase micro extraction (HS-SPME) and submitted to GCMS analysis. Variations in VOCs between the samples were observed and, a direct relationship was observed between of the major constituent detected (α-terpinyl acetate) and the monoterpenes α-thujene, α-pinene, β-pinene, camphene, sabinene and α-limonene that were present in the volatile fractions. Besides α-terpinyl acetate, isobornyl acetate and α-limonene were also major constituents. Variations were observed in VOCs in the analyzed periods. The best cultivation media for the production of VOCs was found to be MS0 (control). Moderate success was achieved by treatment with 2.68 µM and 5:37 µM NAA (Group 2). With 2,4-D (9.0 µM), only the presence of α-terpinyl acetate and isocumene were detected and, with 2.26 µM of 2,4-D was produced mainly α-terpinyl acetate, α-thujene and β-caryophyllene (16.2%). The VOC profiles present in P. ornatus were interpreted using PCA and HCA. The results permitted us to determine the best cultivation media for VOC production and, the PCA and HCA analysis allowed us to recognize four groups among the different treatments from the compounds identified in this set of treatments.

Asymbiotic seed germination and in vitro conservation of Coelogyne nervosa A. Rich. an endemic orchid to Western Ghats.

PubMed

Abraham, Sonia; Augustine, Jomy; Thomas, T Dennis

2012-07-01

Coelogyne nervosa is an epiphytic orchid endemic to Western Ghats, South India. The mature seeds of C. nervosa were cultured on ½ MS (Murashige and Skoog), MS, Kn (Knudson) and VW (Vacin and Went) media to evaluate the seed germination response. Of the four basal media used, MS medium supported maximum seed germination. Further experiments to enhance seed germination were done on MS medium supplemented with various concentrations (10, 20, 30 and 40 %) of coconut water (CW). Thirty percent CW gave the highest response in terms of percent seed germination (96), fresh weight (7.2 mg/seedling) and protocorm length (15.2 mm). Since CW containing medium did not support further seedling growth, each seedling was isolated and cultured on MS medium supplemented with either BA (6-benzylaminopurine) or Kin (kinetin) alone (1.0-4.0 mg/l each) or in combination with NAA (1-naphthaleneacetic acid; 0.2-1.0 mg/l). Maximum growth was observed on MS medium supplemented with BA (3.0 mg/l) and NAA (0.5 mg/l). On this medium, the seedlings reached an average length of 3.6 cm with 2.8 well expanded green leaves per seedling. Similarly optimum, healthy, white root induction (3.3 roots/seedlings) was also observed on the same medium. The rooted seedlings were successfully transplanted to pots with 91 % success. The 2-year-old tissue culture derived plants produced normal flowers and fruits.

In vitro propagation and reintroduction of the endangered Renanthera imschootiana Rolfe.

PubMed

Wu, Kunlin; Zeng, Songjun; Lin, Danni; Teixeira da Silva, Jaime A; Bu, Zhaoyang; Zhang, Jianxia; Duan, Jun

2014-01-01

Renanthera imschootiana Rolfe is an endangered tropical epiphytic orchid that is threatened with extinction due to over-collection and the loss of suitable habitats. In vitro propagation is a useful way to mass produce plants for re-establishment in the wild and for commercial propagation. Seeds collected 150 days after pollination (DAP) were the optimum stage for in vitro culture. Seed germination reached 93.1% on quarter-strength MS (i.e., MS containing a quarter of macro- and micronutrients) medium containing 0.5 mg l(-1) α-naphthaleneacetic acid (NAA), 20% coconut water (CW), 1.0 g l(-1) peptone, 10 g l(-1) sucrose and 1.0 g l(-1) activated charcoal (AC). Quarter-strength MS medium supplemented with 1.0 mg l(-1) BA, 0.5 mg l(-1) NAA, 1.0 g l(-1) peptone, 10 g l(-1) sucrose and 20% CW was suitable for the sub-culture of protocorm-like bodies (PLBs) in which the PLB proliferation ratio was 2.88. Quarter-strength MS medium containing 1.0 mg l(-1) NAA, 1.0 g l(-1) peptone, 100 g l(-1) banana homogenate (BH), and 1.0 g l(-1) AC was suitable for plantlet formation and 95.67% of plantlets developed from PLBs within 60 days of culture. Hyponex N016 medium supplemented with 0.5 mg l(-1) NAA, 1.0 g l(-1) peptone, 20 g l(-1) sucrose, 150 g l(-1) BH, and 1.0 g l(-1) AC was suitable for the in vitro growth of plantlets about 2-cm in height. Plantlets 3-cm in height or taller were transplanted to Chilean sphagnum moss, and 95% of plantlets survived after 60 days in a greenhouse. Three hundred transplanted of seedlings 360-days old were reintroduced into three natural habitats. Highest percentage survival (79.67%) was observed in Yuanjiang Nature Reserve two years after reintroduction, followed by Huolu Mountain forest park (71.33%). This protocol is an efficient means for the large-scale propagation and in vitro and in vivo germplasm conservation of R. imschootiana.

Micropropagation, antinociceptive and antioxidant activities of extracts of Verbena litoralis Kunth (Verbenaceae).

PubMed

Braga, Virgínia F; Mendes, Giselle C; Oliveira, Raphael T R; Soares, Carla Q G; Resende, Cristiano F; Pinto, Leandro C; Santana, Reinaldo de; Viccini, Lyderson F; Raposo, Nádia R B; Peixoto, Paulo H P

2012-03-01

This work describes an efficient micropropagation protocol for Verbena litoralis and the study of the antinociceptive and antioxidant activities in extracts of this species. For the establishment in vitro, surface-sterilization procedures and PVPP showed high efficiency in fungal-bacterial contamination and phenol oxidation controls. Nodal segments cultivation in MS medium supplemented with 6-benzyladenine (7.5 µM)/α-naphthaleneacetic acid (NAA; 0.005 µM) induced multiple shoots. Elongated shoots were rooted with IAA (0.2 µM). Acclimatization rates were elevated and the plants showed the typical features of this species. The hexanic fraction (HF) of powdered leaves presented a radical scavenging activity with IC(50) = 169.3 µg mL(-1). HF showed a non-dose dependent analgesic activity in the writhing test; its antinociceptive activity in the hot plate test was restricted to 500 mg kg(-1), which is the highest dose. The results of this study showed the potential of tissue culture on conservation and large scale multiplication and confirmed the traditional folk medicine use of V. litoralis.

A Genetic Transformation Method for Cadmium Hyperaccumulator Sedum plumbizincicola and Non-hyperaccumulating Ecotype of Sedum alfredii

PubMed Central

Liu, Huan; Zhao, Haixia; Wu, Longhua; Xu, Wenzhong

2017-01-01

The present study demonstrates the development of an Agrobacterium-mediated genetic transformation method for species of the Sedum genus, which includes the Cd/Zn hyperaccumulator Sedum plumbizincicola and the non-hyperaccumulating ecotype of S. alfredii. Multiple shoots were induced from stem nodes of two Sedum plants using Murashige and Skoog (MS) medium containing 0.1 mg/L cytokinin 6-benzyladenine (6-BA) and 1.0 mg/L auxin 1-naphthaleneacetic acid (NAA). The shoot primordia were used as direct targets for Agrobacterium infection. Selection on hygromycin was highly effective in generating Agrobacterium-transformed explants. This callus-free procedure allowed us to obtain transgenic plantlets after rooting hygromycin-resistant shoots on phytohormone-free MS medium containing the antibiotic. The presence and expression of the reporter genes gusA and GFP in transgenic plants were confirmed by a real-time polymerase chain reaction, histochemical GUS assays, and confocal microscopy. This reliable method for genetic transformation of Sedum plants will help us to understand gene functions and the molecular mechanisms underlying Cd hypertolerance and hyperaccumulation in these species. PMID:28670322

Induction of somatic embryogenesis in explants of shoot cultures established from adult Eucalyptus globulus and E. saligna × E. maidenii trees.

PubMed

Corredoira, E; Ballester, A; Ibarra, M; Vieitez, A M

2015-06-01

A reproducible procedure for induction of somatic embryogenesis (SE) from adult trees of Eucalyptus globulus Labill. and the hybrid E. saligna Smith × E. maidenii has been developed for the first time. Somatic embryos were obtained from both shoot apex and leaf explants of all three genotypes evaluated, although embryogenic frequencies were significantly influenced by the species/genotype, auxin and explant type. Picloram was more efficient for somatic embryo induction than naphthaleneacetic acid (NAA), with the highest frequency of induction being obtained in Murashige and Skoog medium containing 40 µM picloram and 40 mg l(-1) gum Arabic, in which 64% of the shoot apex explants and 68.8% of the leaf explants yielded somatic embryos. The embryogenic response of the hybrid was higher than that of the E. globulus, especially when NAA was used. The cultures initiated on picloram-containing medium consisted of nodular embryogenic structures surrounded by a mucilaginous coating layer that emerged from a watery callus developed from the initial explants. Cotyledonary somatic embryos were differentiated after subculture of these nodular embryogenic structures on a medium lacking plant growth regulators. Histological analysis confirmed the bipolar organization of the somatic embryos, with shoot and root meristems and closed procambial tissue that bifurcated into small cotyledons. The root pole was more differentiated than the shoot pole, which appeared to be formed by a few meristematic layers. Maintenance of the embryogenic lines by secondary SE was attained by subculturing individual cotyledonary embryos or small clusters of globular and torpedo embryos on medium with 16.11 µM NAA at 4- to 5-week intervals. Somatic embryos converted into plantlets after being transferred to liquid germination medium although plant regeneration remained poor. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Plant regeneration of Erigeron breviscapus (vant.) Hand. Mazz. and its chromatographic fingerprint analysis for quality control.

PubMed

Liu, Chun-Zhao; Gao, Min; Guo, Bin

2008-01-01

An efficient micropropagation system for Erigeron breviscapus (vant.) Hand. Mazz., an important medicinal plant for heart disease, has been developed. Shoot organogenesis occurred from E. breviscapus leaf explants inoculated on a medium supplemented with a combination of plant growth regulators. On average, 17 shoots per leaf explant were produced after 30 days when they were cultured on MS basal salts and vitamin medium containing 5 microM 6-benzylaminopurine (BAP) and 5 microM 1-naphthaleneacetic acid (NAA). All the regenerated shoots formed complete plantlets on a medium containing 2.5-10 microM indole-3-butyric acid (IBA) within 30 days, and 80.2% of the regenerated plantlets survived and grew vigorously in field conditions. Based on the variation in common peaks and the produced amount of the most important bioactive component, scutellarin, a high performance liquid chromatography (HPLC) fingerprinting system was developed for quality control of these micropropagated plants. Chemical constituents in E. breviscapus micropropagated plants varied during plant development from regeneration to maturation, the latter of which showed the most similar phytochemical profile in comparison with mother plants. The regeneration protocol and HPLC fingerprint analysis developed here provided a new approach to quality control of micropropagated plants producing secondary metabolites with significant implications for germplasm conservation.

Assessing the response of indigenous loquat cultivar Mardan to phytohormones for in vitro shoot proliferation and rooting*

PubMed Central

Abbasi, Nadeem Akhtar; Pervaiz, Tariq; Hafiz, Ishfaq Ahmed; Yaseen, Mehwish; Hussain, Azhar

2013-01-01

In vitro cultures of loquat cultivar Mardan were established using shoot apices after treating with NaOCl (5%, 7%, 10%, 12%, 14% (v/v)) for 12 min and HgCl2 (0.01%, 0.05%, 0.10%, 0.20%, 0.25% (w/v)) for 2 min. A maximum survival rate of 70% was recorded after surface sterilization with 10% NaOCl. Caulogenic response was assessed on Murashige and Skoog (MS) medium fortified with assorted combinations of the cytokinins, benzylaminopurine (BAP), kinetin, and N6-(2-isopentyl)adenine (2iP). Treatment of BAP 1.5 mg/L combined with 2iP 9.0 mg/L and kinetin 1.5 mg/L was found to be optimum for shoot morphogenesis in terms of the number and subsequent growth of shoots, while the highest shoot length was yielded by the combination of BAP 0.5 mg/L, kinetin 0.5 mg/L, and 2iP 3 mg/L. Higher levels of cytokinins induced callogenesis, vitrification and stunted growth to some extent. For rhizogenesis, uniform sized micro-shoots were excised and transferred to half-strength MS medium containing auxins. The best rooting expression was observed with naphthaleneacetic acid (NAA) 1 mg/L combined with indole-3-butyric acid (IBA) 2 mg/L and paclobutrazol (PBZ) 1 mg/L. PMID:24009197

Studies on the Role of N-Acetylaspartic Acid in Mammalian Brain

PubMed Central

Jacobson, K. Bruce

1959-01-01

N-Acetylaspartic acid (NAA) occurs at relatively high concentrations exclusively in the mammalian and avian brain and undergoes rapid rise in level soon after birth (Tallan, 1957). The amount of NAA in brains of mentally abnormal human beings and of young human beings was measured. The route by which NAA is synthesized was shown to involve a direct acetylation of aspartic acid. The degradative activity of the brain toward NAA is slight. Some experiments indicate that NAA in the brain is a physiologically and metabolically active compound. PMID:14406413

Participation of IAA in transduction of gravistimulus in apical cells of moss protonema

NASA Astrophysics Data System (ADS)

Oksyniuk, U. A.; Khorkavtsiv, O. Y.; Lesniak, Y. I.

Growth movements of vascular plant axis organs -- photo-, gravi- and other tropisms -- are tightly connected with IAA transport (Hertel, 1983; Medvedev, 1996; Kiss, 2000). Moss protonema synthesizes IAA (indole-3-acetic acid) and transports it basipetally favouring growth and differentiation of caulonema (Bopp, 1979; Rose, Bopp, 1983; Rose et al., 1983). We aimed at studying the role of IAA in moss protonema gravitropism using exogenous IAA, 1-NAA (1-naphthaleneacetic acid), 2,4D (2,4-dichlorophenoxyacetic acid) and inhibitors of polar IAA transport -- phytotropins NPA (N-1-naphthylphthalamic acid) and TIBA (2,3,5-triiodobenzoic acid). Six-day gravitropic protonema of Ceratodon purpureus and Pohlia nutans were taken for experiments. Auxin and phytotropins solutions were laid on protonema mats the latters being kept in solutions for 30 min. Then the surplus of solutions were poured off and Petri dishes were placed vertically for 6 h. 20 μ M of IAA and of other synthetic auxins did not significantly influence the angle of protonema gravity bending, 40 μ M of the agents, howewer, reduced the per cent of apical cells bendings and their angles. The most expressed influence on the angles of bending had the inhibitors of polar IAA transport -- NPA. 0,1 -- 3,0 μ M of this phytotropin did not change the form of apical cell, did not disturb the general distribution of amyloplasts and did not significantly lower the per cent and the value of gravity bending angle, though 10 μ M of the phytotropin - inhibited gravity bending. The mixture of 1-NAA and NPA having been added into the medium the influence of NPA was lowered and gravitropic growth renewed in course of time. 10 μ M of other phytopropin TIBA also inhibited gravitropism of Ceratodon purpureus and Pohlia nutans protonema. The analysis of basipetal transport of IAA in moss rhizoids and protonema may indicate the availability of special IAA transport in these structures (Bopp, Cerier, 1988). On the basis of the carried out experiments it can be suggested that high concentrations of IAA and 1-NAA result in surplus of IAA cells led, probably, to a destruction of the apical-basal gradient in cells. Our results testify that NPA inhibits the gravitropism stronger than the growth of protonema. The peculiarity of moss protonema is that the growth orientation change is a result of a transference of growth zone in the apical cell dome caused by amyloplasts sedimentation inducing lateral asymmetry of Ca2+ and apical-basal IAA flow what in its turn manifests itself in distribution of IAA and/or Ca2+ channels in apical cell dome plasma membrane ( Schwuchow et al., 2001). The transport of IAA in apical cells, probably, functionally polarizes it and just that polarizing function is dominant in cells with tip growth.

Ex situ conservation of Phyllanthus fraternus Webster and evaluation of genetic fidelity in regenerates using DNA-based molecular marker.

PubMed

Upadhyay, Richa; Kashyap, Sarvesh Pratap; Singh, Chandra Shekhar; Tiwari, Kavindra Nath; Singh, Karuna; Singh, Major

2014-11-01

Germplasm storage of Phyllanthus fraternus by using synseed technology has been optimized. Synseeds were prepared from nodal segments taken from in vitro-grown plantlets. An encapsulation matrix of 3 % sodium alginate and 100 mM calcium chloride with polymerization duration up to 15 min was found most suitable for synseed formation. Maximum plantlet conversion (92.5 ± 2.5 %) was obtained on a growth regulator-free ½-strength solid Murashige and Skoog (MS) medium. Multiple shoot proliferation was optimum on a ½ MS medium containing 0.5 mg/l 6-benzylaminopurine (BAP). Shoots were subjected to rooting on MS media containing 1 mg/l α-naphthaleneacetic acid (NAA) and acclimatized successfully. Encapsulated nodal segments can be stored for up to 90 days with a survival frequency of 47.33 %. The clonal fidelity of synseed-derived plantlets was also assessed and compared with that of the mother plant using rapid amplified polymorphic DNA and inter-simple sequence repeat analysis. No changes in molecular profiles were observed among the synseed-derived plantlets and mother plant, which confirms the genetic stability of regenerates. This synseed production protocol could be useful for in vitro multiplication, short-term storage, and exchange of germplasm of this important antiviral and hepatoprotective plant.

Naturally induced secretions of the potato cyst nematode co-stimulate the proliferation of both tobacco leaf protoplasts and human peripheral blood mononuclear cells.

PubMed

Goverse, A; Rouppe van der Voort, J; Roppe van der Voort, C; Kavelaars, A; Smant, G; Schots, A; Bakker, J; Helder, J

1999-10-01

Naturally induced secretions from infective juveniles of the potato cyst nematode Globodera rostochiensis co-stimulate the proliferation of tobacco leaf protoplasts in the presence of the synthetic phytohormones alpha-naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BAP). With the use of a protoplast-based bioassay, a low-molecular-weight peptide(s) (< 3 kDa) was shown to be responsible for the observed effect. This mitogenic oligopeptide(s) is functionally dissimilar to auxin and cytokinin and, in addition, it does not change the sensitivity of the protoplasts toward these phytohormones. In combination with the mitogen phytohemagglutinin (PHA), cyst nematode secretions also co-stimulated mitogenesis in human peripheral blood mononuclear cells (PBMC). The stimulation of plant cells isolated from nontarget tissue--these nematodes normally invade the roots of potato plants--suggests the activation of a general signal transduction mechanism(s) by an oligopeptide(s) secreted by the nematode. Whether a similar oligopeptide-induced mechanism underlies human PBMC activation remains to be investigated. Reactivation of the cell cycle is a crucial event in feeding cell formation by cyst nematodes. The secretion of a mitogenic low-molecular-weight peptide(s) by infective juveniles of the potato cyst nematode could contribute to the redifferentiation of plant cells into such a feeding cell.

Structural determinants and cellular environment define processed actin as the sole substrate of the N-terminal acetyltransferase NAA80.

PubMed

Goris, Marianne; Magin, Robert S; Foyn, Håvard; Myklebust, Line M; Varland, Sylvia; Ree, Rasmus; Drazic, Adrian; Bhambra, Parminder; Støve, Svein I; Baumann, Markus; Haug, Bengt Erik; Marmorstein, Ronen; Arnesen, Thomas

2018-04-24

N-terminal (Nt) acetylation is a major protein modification catalyzed by N-terminal acetyltransferases (NATs). Methionine acidic N termini, including actin, are cotranslationally Nt acetylated by NatB in all eukaryotes, but animal actins containing acidic N termini, are additionally posttranslationally Nt acetylated by NAA80. Actin Nt acetylation was found to regulate cytoskeletal dynamics and motility, thus making NAA80 a potential target for cell migration regulation. In this work, we developed potent and selective bisubstrate inhibitors for NAA80 and determined the crystal structure of NAA80 in complex with such an inhibitor, revealing that NAA80 adopts a fold similar to other NAT enzymes but with a more open substrate binding region. Furthermore, in contrast to most other NATs, the substrate specificity of NAA80 is mainly derived through interactions between the enzyme and the acidic amino acids at positions 2 and 3 of the actin substrate and not residues 1 and 2. A yeast model revealed that ectopic expression of NAA80 in a strain lacking NatB activity partially restored Nt acetylation of NatB substrates, including yeast actin. Thus, NAA80 holds intrinsic capacity to posttranslationally Nt acetylate NatB-type substrates in vivo. In sum, the presence of a dominant cotranslational NatB in all eukaryotes, the specific posttranslational actin methionine removal in animals, and finally, the unique structural features of NAA80 leave only the processed actins as in vivo substrates of NAA80. Together, this study reveals the molecular and cellular basis of NAA80 Nt acetylation and provides a scaffold for development of inhibitors for the regulation of cytoskeletal properties. Copyright © 2018 the Author(s). Published by PNAS.

Somatic embryogenesis, scanning electron microscopy, histology and biochemical analysis at different developing stages of embryogenesis in six date palm (Phoenix dactylifera L.) cultivars.

PubMed

Aslam, Junaid; Khan, Saeed Ahmad; Cheruth, Abdul Jaleel; Mujib, Abdul; Sharma, Maheshwar Pershad; Srivastava, Prem Shanker

2011-10-01

An efficient somatic embryogenesis system has been established in six date palm (Phoenix dactylifera L.) cultivars (Barhee, Zardai, Khalasah, Muzati, Shishi and Zart). Somatic embryogenesis (SE) was growth regulators and cultivars dependent. Friable embryogenic callus was induced from excised shoot tips on MS medium supplemented with various auxins particularly 2,4-dichlorophenoxyacetic acid (2,4-D, 1.5 mg 1(-l)). Suspension culture increased embryogenesis potentiality. Only a-naphthaleneacetic acid (NAA, 0.5 mg 1(-1)) produced somatic embryos in culture. Somatic embryos germinated and converted into plantlets in N(6)-benzyladenine (BAP, 0.75 mg 1(-l)) added medium following a treatment with thidiazuron (TDZ, 1.0 mg 1(-l)) for maturation. Scanning electron microscopy showed early stages of somatic embryo particularly, globular types, and was in masses. Different developing stages of embryogenesis (heart, torpedo and cotyledonary) were observed under histological preparation of embryogenic callus. Biochemical screening at various stages of somatic embryogenesis (embryogenic callus, somatic embryos, matured, germinated embryos and converted plantlets) of date palm cultivars has been conducted and discussed in detail. The result discussed in this paper indicates that somatic embryos were produced in numbers and converted plantlets can be used as a good source of alternative propagation. Genetic modification to the embryo precursor cell may improve the fruit quality and yield further.

Somatic embryogenesis, scanning electron microscopy, histology and biochemical analysis at different developing stages of embryogenesis in six date palm (Phoenix dactylifera L.) cultivars

PubMed Central

Aslam, Junaid; Khan, Saeed Ahmad; Cheruth, Abdul Jaleel; Mujib, Abdul; Sharma, Maheshwar Pershad; Srivastava, Prem Shanker

2011-01-01

An efficient somatic embryogenesis system has been established in six date palm (Phoenix dactylifera L.) cultivars (Barhee, Zardai, Khalasah, Muzati, Shishi and Zart). Somatic embryogenesis (SE) was growth regulators and cultivars dependent. Friable embryogenic callus was induced from excised shoot tips on MS medium supplemented with various auxins particularly 2,4-dichlorophenoxyacetic acid (2,4-D, 1.5 mg 1−l). Suspension culture increased embryogenesis potentiality. Only a-naphthaleneacetic acid (NAA, 0.5 mg 1−1) produced somatic embryos in culture. Somatic embryos germinated and converted into plantlets in N6-benzyladenine (BAP, 0.75 mg 1−l) added medium following a treatment with thidiazuron (TDZ, 1.0 mg 1−l) for maturation. Scanning electron microscopy showed early stages of somatic embryo particularly, globular types, and was in masses. Different developing stages of embryogenesis (heart, torpedo and cotyledonary) were observed under histological preparation of embryogenic callus. Biochemical screening at various stages of somatic embryogenesis (embryogenic callus, somatic embryos, matured, germinated embryos and converted plantlets) of date palm cultivars has been conducted and discussed in detail. The result discussed in this paper indicates that somatic embryos were produced in numbers and converted plantlets can be used as a good source of alternative propagation. Genetic modification to the embryo precursor cell may improve the fruit quality and yield further. PMID:23961149

Phytochemical and biotechnological studies on Schisandra chinensis cultivar Sadova No. 1-a high utility medicinal plant.

PubMed

Szopa, Agnieszka; Klimek-Szczykutowicz, Marta; Kokotkiewicz, Adam; Maślanka, Anna; Król, Agata; Luczkiewicz, Maria; Ekiert, Halina

2018-06-01

In the presented work, raw materials (fruits and leaves) and in vitro biomass of a highly productive Schisandra chinensis Sadova No. 1 cultivar (SchS) were evaluated for the production of therapeutically useful schisandra lignans (SL). In vitro cultures of SchS were initiated, followed by extensive optimization studies focused on maximizing secondary metabolite production, with the aim of establishing a sustainable source of SL. Different cultivation systems (agar, agitated, bioreactor), experiment times (10, 20, 30, 40, 50 and 60 days) and plant growth regulators (6-benzyladenine-BA and 1-naphthaleneacetic acid-NAA, from 0 to 3 mg/l) in Murashige-Skoog (MS) medium were tested. Moreover, an elicitation procedure was applied to bioreactor-grown microshoots in order to increase SL production. Validated HPLC-DAD protocol enabled to detect fourteen SL in the extracts from in vitro and in vivo materials. The main compounds in the in vitro cultures were as follows: schisandrin (max. 176.3 mg/100 g DW), angeloylgomisin Q (max. 85.1 mg/100 g DW), gomisin A (max. 71.4 mg/100 g DW) and angeloylgomisin H (max. 67.0 mg/100 g DW). The highest total SL content (490.3 mg/100 g DW) was obtained in extracts from the biomass of agar cultures cultivated for 30 days on the MS medium variant containing 3 mg/l BA and 1 mg/l NAA. This amount was 1.32 times lower than in fruit extracts (646.0 mg/100 g DW) and 2.04 times higher than in leaf extracts (240.7 mg/100 g DW). The study demonstrated that SchS is a rich source of SL, thus proving its value for medical, cosmetic and food industry.

Advances in the mechanism and understanding of site-selective noncanonical amino acid incorporation.

PubMed

Antonczak, Alicja K; Morris, Josephine; Tippmann, Eric M

2011-08-01

There are many approaches to introduce non-native functionality into proteins either translationally or post-translationally. When a noncanonical amino acid (NAA) is incorporated translationally, the host organism's existing translational machinery is relied upon to insert the amino acid by the same well-established mechanisms used by the host to achieve high fidelity insertion of its canonical amino acids. Research into the in vivo incorporation of NAAs has typically concentrated on evolving or engineering aminoacyl tRNA synthetases (aaRSs); however, new studies have increasingly focused on other members of the translational apparatus, for example entire ribosomes, in attempts to increase the fidelity and efficiency of incorporation of ever more structurally diverse NAAs. As the biochemical methods of NAA systems increase in complexity, it is informative to ask whether the 'rules' for canonical translation (i.e. aaRSs, tRNA, ribosomes, elongation factors, amino acid uptake, and metabolism) hold for NAA systems, or whether new rules are warranted. Here, recent advances in introducing novel chemical functionality into proteins are highlighted. Copyright © 2011 Elsevier Ltd. All rights reserved.

An Efficient In Vitro Propagation Protocol of Cocoyam [Xanthosoma sagittifolium (L) Schott

PubMed Central

Sama, Anne E.; Hughes, Harrison G.; Abbas, Mohamed S.; Shahba, Mohamed A.

2012-01-01

Sprouted corm sections of “South Dade” white cocoyam were potted and maintained in a greenhouse for 8 weeks. Shoot tips of 3–5 mm comprising the apical meristem with 4–6 leaf primordial, and approximately 0.5 mm of corm tissue at the base. These explants were treated to be used into the culture medium. A modified Gamborg's B5 mineral salts supplemented with 0.05 μM 1-naphthaleneacetic acid (NAA) were used throughout the study. Thidiazuron (TDZ) solution containing 0.01% dimethyl sulfoxide (DMSO) was used. Erlenmeyer flasks and test tubes were used for growing cultures. The effect of different media substrate, thidiazuron, and the interaction between TDZ and Benzylaminopurine (BAP) on cocoyam culture were tested. Results indicated that cocoyam can be successfully micropropagated in vitro through various procedures. All concentrations tested (5–20 μM BAP and 1–4 μM TDZ) produced more axillary shoots per shoot tip than the control without cytokinins. Greater proliferation rates were obtained through the use of 20 μM BAP and 2 μM TDZ, respectively, 12 weeks from initiation. Shoots produced with BAP were larger and more normal in appearance than those produced with TDZ, which were small, compressed, and stunted. The use of stationary liquid media is recommended for economic reasons. PMID:22666109

Schisandra lignans production regulated by different bioreactor type.

PubMed

Szopa, Agnieszka; Kokotkiewicz, Adam; Luczkiewicz, Maria; Ekiert, Halina

2017-04-10

Schisandra chinensis (Chinese magnolia vine) is a rich source of therapeutically relevant dibenzocyclooctadiene lignans with anticancer, immunostimulant and hepatoprotective activities. In this work, shoot cultures of S. chinensis were grown in different types of bioreactors with the aim to select a system suitable for the large scale in vitro production of schisandra lignans. The cultures were maintained in Murashige-Skoog (MS) medium supplemented with 3mg/l 6-benzylaminopurine (BA) and 1mg/l 1-naphthaleneacetic acid (NAA). Five bioreactors differing with respect to cultivation mode were tested: two liquid-phase systems (baloon-type bioreactor and bubble-column bioreactor with biomass immobilization), the gas-phase spray bioreactor and two commercially available temporary immersion systems: RITA ® and Plantform. The experiments were run for 30 and 60 days in batch mode. The harvested shoots were evaluated for growth and lignan content determined by LC-DAD and LC-DAD-ESI-MS. Of the tested bioreactors, temporary immersion systems provided the best results with respect to biomass production and lignan accumulation: RITA ® bioreactor yielded 17.86g/l (dry weight) during 60 day growth period whereas shoots grown for 30 days in Plantform bioreactor contained the highest amount of lignans (546.98mg/100g dry weight), with schisandrin, deoxyschisandrin and gomisin A as the major constituents (118.59, 77.66 and 67.86mg/100g dry weight, respectively). Copyright © 2017 Elsevier B.V. All rights reserved.

Galanthamine, an anti-cholinesterase drug, effects plant growth and development in Artemisia tridentata Nutt. via modulation of auxin and neurotransmitter signaling.

PubMed

Turi, Christina E; Axwik, Katarina E; Smith, Anderson; Jones, A Maxwell P; Saxena, Praveen K; Murch, Susan J

2014-01-01

Galanthamine is a naturally occurring acetylcholinesterase (AchE) inhibitor that has been well established as a drug for treatment of mild to moderate Alzheimer disease, but the role of the compound in plant metabolism is not known. The current study was designed to investigate whether galanthamine could redirect morphogenesis of Artemisia tridentata Nutt. cultures by altering concentration of endogenous neurosignaling molecules acetylcholine (Ach), auxin (IAA), melatonin (Mel), and serotonin (5HT). Exposure of axenic A. tridentata cultures to 10 µM galanthamine decreased the concentration of endogenous Ach, IAA, MEL, and AchE, and altered plant growth in a manner reminiscent of 2-4D toxicity. Galanthamine itself demonstrated IAA activity in an oat coleoptile elongation bioassay, 20 µM galanthamine showed no significant difference compared with 5 μM IAA or 5 μM 1-Naphthaleneacetic acid (NAA). Metabolomic analysis detected between 20,921 to 27,891 compounds in A. tridentata plantlets and showed greater commonality between control and 5 µM treatments. Furthermore, metabolomic analysis putatively identified coumarins scopoletin/isoscopoletin, and scopolin in A. tridentata leaf extracts and these metabolites linearly increased in response to galanthamine treatments. Overall, these data indicate that galanthamine is an allelopathic phytochemical and support the hypothesis that neurologically active compounds in plants help ensure plant survival and adaptation to environmental challenges.

Galanthamine, an anticholinesterase drug, effects plant growth and development in Artemisia tridentate Nutt. via modulation of auxin and neutrotransmitter signaling.

PubMed

Turi, Christina E; Axwik, Katarina E; Smith, Anderson; Jones, A Maxwell P; Saxena, Praveen K; Murch, Susan J

2014-01-01

Galanthamine is a naturally occurring acetylcholinesterase (AchE) inhibitor that has been well established as a drug for treatment of mild to moderate Alzheimer disease, but the role of the compound in plant metabolism is not known. The current study was designed to investigate whether galanthamine could redirect morphogenesis of Artemisia tridentata Nutt. cultures by altering concentration of endogenous neurosignaling molecules acetylcholine (Ach), auxin (IAA), melatonin (Mel), and serotonin (5HT). Exposure of axenic A. tridentata cultures to 10 µM galanthamine decreased the concentration of endogenous Ach, IAA, MEL, and AchE, and altered plant growth in a manner reminiscent of 2-4D toxicity. Galanthamine itself demonstrated IAA activity in an oat coleotile elongation bioassay, 20 µM galanthamine showed no significant difference compared with 5 μM IAA or 5 μM 1-Naphthaleneacetic acid (NAA). Metabolomic analysis detected between 20,921 to 27,891 compounds in A. tridentata plantlets and showed greater commonality between control and 5 µM treatments. Furthermore, metabolomic analysis putatively identified coumarins scopoletin/isoscopoletin, and scopolin in A. tridentata leaf extracts and these metabolites linearly increased in response to galanthamine treatments. Overall, these data indicate that galanthamine is an allelopathic phytochemical and support the hypothesis that neurologically active compounds in plants help ensure plant survival and adaptation to environmental challenges.

A lower pH value benefits regeneration of Trichosanthes kirilowii by somatic embryogenesis, involving rhizoid tubers (RTBs), a novel structure.

PubMed

Xu, Ke-dong; Chang, Yun-xia; Zhang, Ju; Wang, Pei-long; Wu, Jian-xin; Li, Yan-yan; Wang, Xiao-wen; Wang, Wei; Liu, Kun; Zhang, Yi; Yu, De-shui; Liao, Li-bing; Li, Yi; Ma, Shu-ya; Tan, Guang-xuan; Li, Cheng-wei

2015-03-06

A new approach was established for the regeneration of Trichosanthes kirilowii from root, stem, and leaf explants by somatic embryogenesis (SE), involving a previously unreported SE structure, rhizoid tubers (RTBs). During SE, special rhizoids were first induced from root, stem, and leaf explants with average rhizoid numbers of 62.33, 40.17, and 11.53 per explant, respectively, on Murashige and Skoog (MS) medium (pH 4.0) supplemented with 1.0 mg/L 1-naphthaleneacetic acid (NAA) under dark conditions. Further, one RTB was formed from each of the rhizoids on MS medium (pH 4.0) supplemented with 20 mg/L thidiazuron (TDZ) under light conditions. In the suitable range (pH 4.0-9.0), a lower pH value increased the induction of rhizoids and RTBs. Approximately 37.77, 33.47, and 31.07% of in vivo RTBs from root, stem, and leaf explants, respectively, spontaneously developed into multiple plantlets on the same MS medium (supplemented with 20 mg/L TDZ) for induction of RTBs, whereas >95.00% of in vitro RTBs from each kind of explant developed into multiple plantlets on MS medium supplemented with 5.0 mg/L 6-benzylaminopurine (BAP). Morphological and histological analyses revealed that RTB is a novel type of SE structure that develops from the cortex cells of rhizoids.

A Lower pH Value Benefits Regeneration of Trichosanthes kirilowii by Somatic Embryogenesis, Involving Rhizoid Tubers (RTBs), a Novel Structure

PubMed Central

Xu, Ke-dong; Chang, Yun-xia; Zhang, Ju; Wang, Pei-long; Wu, Jian-xin; Li, Yan-yan; Wang, Xiao-wen; Wang, Wei; Liu, Kun; Zhang, Yi; Yu, De-shui; Liao, Li-bing; Li, Yi; Ma, Shu-ya; Tan, Guang-xuan; Li, Cheng-wei

2015-01-01

A new approach was established for the regeneration of Trichosanthes kirilowii from root, stem, and leaf explants by somatic embryogenesis (SE), involving a previously unreported SE structure, rhizoid tubers (RTBs). During SE, special rhizoids were first induced from root, stem, and leaf explants with average rhizoid numbers of 62.33, 40.17, and 11.53 per explant, respectively, on Murashige and Skoog (MS) medium (pH 4.0) supplemented with 1.0 mg/L 1-naphthaleneacetic acid (NAA) under dark conditions. Further, one RTB was formed from each of the rhizoids on MS medium (pH 4.0) supplemented with 20 mg/L thidiazuron (TDZ) under light conditions. In the suitable range (pH 4.0–9.0), a lower pH value increased the induction of rhizoids and RTBs. Approximately 37.77, 33.47, and 31.07% of in vivo RTBs from root, stem, and leaf explants, respectively, spontaneously developed into multiple plantlets on the same MS medium (supplemented with 20 mg/L TDZ) for induction of RTBs, whereas >95.00% of in vitro RTBs from each kind of explant developed into multiple plantlets on MS medium supplemented with 5.0 mg/L 6-benzylaminopurine (BAP). Morphological and histological analyses revealed that RTB is a novel type of SE structure that develops from the cortex cells of rhizoids. PMID:25744384

Improvement of Nicotinic Acid and Nicotinamide Analysis in Meats and Meat Products by HPLC and LC-MS/MS with Solid-Phase Extraction.

PubMed

Hiki, Asako; Yamajima, Yukiko; Uematsu, Yoko

2016-01-01

A method for nicotinic acid (NA) and nicotinamide (NAA) analysis in meats was developed. NA and NAA were extracted from meats or meat products with metaphosphate aqueous solution. The extract was cleaned up with an Oasis MCX cartridge. The cartridge was washed with 2% acetic acid (v/v) and acetic acid-methanol solution. NA and NAA were eluted with ammonia-methanol solution. NA and NAA in the eluate were chromatographed on a Scherzo SM-C18 (3.0×150 mm, 3.0 μm) column with 20 mmol/L ammonium acetate containing 0.1% acetic acid-acetonitrile (97 : 3) as a mobile phase and were monitored at 261 nm. Quantification was performed by LC and LC-MS/MS. Calibration curves showed high linearity (correlation coefficient>0.998) between 1-25 μg/mL for LC and LC-MS/MS. Recoveries were 84-108% (CV≦5.8%) by HPLC and 79-105% (CV≦9.0%) by LC-MS/MS. The limit of quantitation for NA was 0.005-0.01 g/kg and that for NAA was 0.01-0.02 g/kg.

N-Acetylaspartate in the CNS: From Neurodiagnostics to Neurobiology

PubMed Central

Moffett, John R.; Ross, Brian; Arun, Peethambaran; Madhavarao, Chikkathur N.; Namboodiri, M. A. A.

2007-01-01

The brain is unique among organs in many respects, including its mechanisms of lipid synthesis and energy production. The nervous system-specific metabolite N-acetylaspartate (NAA), which is synthesized from aspartate and acetyl-coenzyme A in neurons, appears to be a key link in these distinct biochemical features of CNS metabolism. During early postnatal CNS development, the expression of lipogenic enzymes in oligodendrocytes, including the NAA-degrading enzyme aspartoacylase (ASPA), is increased along with increased NAA production in neurons. NAA is transported from neurons to the cytoplasm of oligodendrocytes, where ASPA cleaves the acetate moiety for use in fatty acid and steroid synthesis. The fatty acids and steroids produced then go on to be used as building blocks for myelin lipid synthesis. Mutations in the gene for ASPA result in the fatal leukodystrophy Canavan disease, for which there is currently no effective treatment. Once postnatal myelination is completed, NAA may continue to be involved in myelin lipid turnover in adults, but it also appears to adopt other roles, including a bioenergetic role in neuronal mitochondria. NAA and ATP metabolism appear to be linked indirectly, whereby acetylation of aspartate may facilitate its removal from neuronal mitochondria, thus favoring conversion of glutamate to alpha ketoglutarate which can enter the tricarboxylic acid cycle for energy production. In its role as a mechanism for enhancing mitochondrial energy production from glutamate, NAA is in a key position to act as a magnetic resonance spectroscopy marker for neuronal health, viability and number. Evidence suggests that NAA is a direct precursor for the enzymatic synthesis of the neuron specific dipeptide N-acetylaspartylglutamate, the most concentrated neuropeptide in the human brain. Other proposed roles for NAA include neuronal osmoregulation and axon-glial signaling. We propose that NAA may also be involved in brain nitrogen balance. Further research will be required to more fully understand the biochemical functions served by NAA in CNS development and activity, and additional functions are likely to be discovered. PMID:17275978

In vitro propagation and production of cardiotonic glycosides in shoot cultures of Digitalis purpurea L. by elicitation and precursor feeding.

PubMed

Patil, Jitendra Gopichand; Ahire, Mahendra Laxman; Nitnaware, Kirti Manik; Panda, Sayantan; Bhatt, Vijay P; Kishor, Polavarapu B Kavi; Nikam, Tukaram Dayaram

2013-03-01

Digitalis purpurea L. (Scrophulariaceae; Foxglove) is a source of cardiotonic glycosides such as digitoxin and digoxin which are commercially applied in the treatment to strengthen cardiac diffusion and to regulate heart rhythm. This investigation deals with in vitro propagation and elicited production of cardiotonic glycosides digitoxin and digoxin in shoot cultures of D. purpurea L. In vitro germinated seedlings were used as a primary source of explants. Multiple shoot formation was achieved for three explant types (nodal, internodal, and leaf) cultured on Murashige and Skoog (MS) medium with several treatments of cytokinins (6-benzyladenine-BA; kinetin-Kin; and thidiazuron-TDZ) and auxins (indole-3-acetic acid-IAA; α-naphthaleneacetic acid-NAA; and 2,4-dichlorophenoxy acetic acid-2,4-D). Maximum multiple shoots (12.7 ± 0.6) were produced from nodal explants on MS + 7.5 μM BA. Shoots were rooted in vitro on MS containing 15 μM IAA. Rooted plantlets were successfully acclimatized. To further maintain the multiple shoot induction, mother tissue was cut into four equal parts and repeatedly sub-cultured on fresh shoot induction liquid medium after each harvest. On adaptation of this strategy, an average of 18 shoots per explant could be produced. This strategy was applied for the production of biomass and glycosides digitoxin and digoxin in shoot cultures on MS medium supplemented with 7.5 μM BA and several treatments with plant growth regulators, incubation period, abiotic (salicylic acid, mannitol, sorbitol, PEG-6000, NaCl, and KCl), biotic (Aspergillus niger, Helminthosporium sp., Alternaria sp., chitin, and yeast extract) elicitors, and precursors (progesterone, cholesterol, and squalene). The treatment of KCl, mycelial mass of Helminthosporium sp., and progesterone were highly effective for the production of cardenolides. In the presence of progesterone (200 to 300 mg/l), digitoxin and digoxin accumulation was enhanced by 9.1- and 11.9-folds respectively.

Influence of nitrogen substrates and substrate C:N ratios on the nitrogen isotopic composition of amino acids from the marine bacterium Vibrio harveyi

NASA Astrophysics Data System (ADS)

Maki, K.; Ohkouchi, N.; Chikaraishi, Y.; Fukuda, H.; Miyajima, T.; Nagata, T.

2014-09-01

Nitrogen (N) isotopic compositions of individual hydrolysable amino acids (δ15NAAs) in N pools have been increasingly used for trophic position assessment and evaluation of sources and transformation processes of organic matter in marine environments. However, there are limited data about variability in δ15NAAs patterns and how this variability influences marine bacteria, an important mediator of trophic transfer and organic matter transformation. We explored whether marine bacterial δ15NAAs profiles change depending on the type and C:N ratio of the substrate. The δ15NAAs profile of a marine bacterium, Vibrio harveyi, was examined using medium containing either glutamate, alanine or ammonium as the N source [substrate C:N ratios (range, 3 to 20) were adjusted with glucose]. The data were interpreted as a reflection of isotope fractionations associated with de novo synthesis of amino acids by bacteria. Principal component analysis (PCA) using the δ15N offset values normalized to glutamate + glutamine δ15N revealed that δ15NAAs profiles differed depending on the N source and C:N ratio of the substrate. High variability in the δ15N offset of alanine and valine largely explained this bacterial δ15NAAs profile variability. PCA was also conducted using bacterial and phytoplankton (cyanobacteria and eukaryotic algae) δ15NAAs profile data reported previously. The results revealed that bacterial δ15NAAs patterns were distinct from those of phytoplankton. Therefore, the δ15NAAs profile is a useful indicator of biochemical responses of bacteria to changes in substrate conditions, serving as a potentially useful method for identifying organic matter sources in marine environments.

In vitro studies on the putative function of N-acetylaspartate as an osmoregulator.

PubMed

Tranberg, Mattias; Abbas, Abdul-Karim; Sandberg, Mats

2007-07-01

Efflux and tissue content of N-acetylaspartate (NAA) and amino acids were evaluated from cultured and acutely prepared hippocampal slices in response to changes in osmolarity. The osmoregulator taurine, but not NAA, was lost from both types of slices after moderate reductions in extracellular osmolarity (-60 mOsm) for 10-48 h. Hypoosmotic shock (-166 mOsm) for 5 min resulted in unselective efflux of several amino acids from acutely prepared slices. Notably, the efflux of taurine, but not NAA, was prominent also after the shock. Efflux of NAA was markedly enhanced by NMDA and high K(+), in particular after the stimulation period. The high K(+)-mediated efflux was decreased by high extracellular osmolarity and a NMDA-receptor antagonist. The results indicate that NAA efflux can be induced by a sudden non-physiological decrease in extracellular osmolarity but not by prolonged more moderate changes in osmolarity. The mechanisms behind the efflux of NAA by high K(+) are complex and may involve both swelling and activation of NMDA-receptors.

Effect of cytokinins and auxins on the growth of free-living conchocelis of Porphyra yezoensis

NASA Astrophysics Data System (ADS)

de-Lin, Duan; Xiu-Geng, Fei; Hong-Xu, Ren; Xiong, Chen; Ying, Zhu

1995-09-01

IAA 3-Indolylacetic acid, NAA a-Naphthylacetic acid and cytokinins in PESI culture medium were used in a study on the effects of plant hormones on the growth of free-living conchocelis of Porphyra yezoensis which showed that its growth in medium with cytokinins, IAA and NAA was more rapid than that in medium with non—phytohormones; that the optimal concentrations for promoting growth were 10 μg/L for IAA and ZA (Zeatin), and 0.1 μg/L for BA 6-Benzyl amino purine and KIN 6-Furfurylamino- purine. Mix use of NAA, IAA and cytokinins, NAA/ZA 1-1000/1 μg/L, NAA/BA 10/1-1000 μg/L, NAA/KIN 1/1-1000 μg/L promoted growth. IAA/ZA 0.1-1/0.1-1 μg/L; IAA/BA 0.1-1/0.1-10 μg/L IAA/KIN 1/0.1-1000 μg/L also promoted growth.

Specificity and Versatility of Substrate Binding Sites in Four Catalytic Domains of Human N-Terminal Acetyltransferases

PubMed Central

Grauffel, Cédric; Abboud, Angèle; Liszczak, Glen; Marmorstein, Ronen; Arnesen, Thomas; Reuter, Nathalie

2012-01-01

Nt-acetylation is among the most common protein modifications in eukaryotes. Although thought for a long time to protect proteins from degradation, the role of Nt-acetylation is still debated. It is catalyzed by enzymes called N-terminal acetyltransferases (NATs). In eukaryotes, several NATs, composed of at least one catalytic domain, target different substrates based on their N-terminal sequences. In order to better understand the substrate specificity of human NATs, we investigated in silico the enzyme-substrate interactions in four catalytic subunits of human NATs (Naa10p, Naa20p, Naa30p and Naa50p). To date hNaa50p is the only human subunit for which X-ray structures are available. We used the structure of the ternary hNaa50p/AcCoA/MLG complex and a structural model of hNaa10p as a starting point for multiple molecular dynamics simulations of hNaa50p/AcCoA/substrate (substrate = MLG, EEE, MKG), hNaa10p/AcCoA/substrate (substrate = MLG, EEE). Nine alanine point-mutants of the hNaa50p/AcCoA/MLG complex were also simulated. Homology models of hNaa20p and hNaa30p were built and compared to hNaa50p and hNaa10p. The simulations of hNaa50p/AcCoA/MLG reproduce the interactions revealed by the X-ray data. We observed strong hydrogen bonds between MLG and tyrosines 31, 138 and 139. Yet the tyrosines interacting with the substrate’s backbone suggest that their role in specificity is limited. This is confirmed by the simulations of hNaa50p/AcCoA/EEE and hNaa10p/AcCoA/MLG, where these hydrogen bonds are still observed. Moreover these tyrosines are all conserved in hNaa20p and hNaa30p. Other amino acids tune the specificity of the S1’ sites that is different for hNaa10p (acidic), hNaa20p (hydrophobic/basic), hNaa30p (basic) and hNaa50p (hydrophobic). We also observe dynamic correlation between the ligand binding site and helix that tightens under substrate binding. Finally, by comparing the four structures we propose maps of the peptide-enzyme interactions that should help rationalizing substrate-specificity and lay the ground for inhibitor design. PMID:23285125

In vitro propagation, carotenoid, fatty acid and tocopherol content of Ajuga multiflora Bunge.

PubMed

Sivanesan, Iyyakkannu; Saini, Ramesh Kumar; Noorzai, Rafi; Zamany, Ahmad Jawid; Kim, Doo Hwan

2016-06-01

The effect of plant growth regulators on shoot proliferation from shoot tip explants of Ajuga multiflora was studied. The highest number of shoots (17.1) was observed when shoot tip explants were cultured on Murashige and Skoog (MS) medium fortified with 8.0 µM 6-Benzyladenine (BA) and 2.7 µM α-naphthaleneacetic acid (NAA). The mean number of shoots per explant was increased 1.6-fold in liquid medium as compared with semi-solid medium. Maximum rooting (100 %) with an average of 7.2 roots per shoot was obtained on MS basal medium. Rooted plantlets were successfully acclimatised in the greenhouse with 100 % survival rate. Composition of carotenoids, fatty acids and tocopherols was also studied from leaves of greenhouse-grown plants and in vitro-regenerated shoots of A. multiflora. The greatest amounts of carotenoids, fatty acids and tocopherols were obtained from leaves of in vitro-regenerated shoots cultured on MS basal medium, followed by leaves of greenhouse-grown plants and leaves of in vitro-regenerated shoots cultured on MS basal medium with 2.0 µM BA or thidiazuron. The most abundant carotenoid in A. multiflora leaves was all-E-lutein (89.4-382.6 μg g -1  FW) followed by all-E-β-carotene (32.0-156.7 μg g -1  FW), 9'-Z-neoxanthin (14.2-63.4 μg g -1  FW), all-E-violaxanthin (13.0-45.9 μg g -1  FW), all-E-zeaxanthin (1.3-2.5 μg g -1  FW) and all-E-β-cryptoxanthin (0.3-0.9 μg g -1  FW). α-Tocopherol was the predominant tocopherol in A. multiflora leaves. Linolenic acid (49.03-52.59 %) was detected in higher amounts in A. multiflora leaf samples followed by linoleic acid (18.95-21.39 %) and palmitic acid (15.79-18.66 %).

Dynamic relationship between neurostimulation and N-acetylaspartate metabolism in the human visual cortex: evidence that NAA functions as a molecular water pump during visual stimulation.

PubMed

Baslow, Morris H; Hrabe, Jan; Guilfoyle, David N

2007-01-01

N-acetyl-l-aspartic acid (NAA), an amino acid synthesized and stored primarily in neurons in the brain, has been proposed to be a molecular water pump (MWP) whose function is to rapidly remove water from neurons against a water gradient. In this communication, we describe the results of a functional (1)H proton magnetic resonance spectroscopy (fMRS) study, and provide evidence that in the human visual cortex, over a 10-min period of visual stimulation, there are stimulation-induced graded changes in the NAA MRS signal from that of a preceding 10-min baseline period with a decline in the NAA signal of 13.1% by the end of the 10-min stimulation period. Upon cessation of visual stimulation, the NAA signal gradually increases during a 10-min recovery period and once again approaches the baseline level. Because the NAA MRS signal reflects the NAA concentration, these changes indicate rapid focal changes in its concentration, and transient changes in its intercompartmental metabolism. These include its rates of synthesis and efflux from neurons and its hydrolysis by oligodendrocytes. During stimulation, the apparent rate of NAA efflux and hydrolysis increased 14.2 times, from 0.55 to 7.8 micromol g(-1) h(-1). During recovery, the apparent rate of synthesis increased 13.3 times, from 0.55 to 7.3 micromol g(-1) h(-1). The decline in the NAA signal during stimulation suggests that a rapid increase in the rate of NAA-obligated water release to extracellular fluid (ECF) is the initial and seminal event in response to neurostimulation. It is concluded that the NAA metabolic cycle in the visual cortex is intimately linked to rates of neuronal signaling, and that the functional cycle of NAA is associated with its release to ECF, thus supporting the hypothesis that an important function of the NAA metabolic cycle is that of an efflux MWP.

78 FR 30213 - 1-Naphthaleneacetic acid; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-22

... Industrial Classification System (NAICS) codes is not intended to be exhaustive, but rather provides a guide... filing. Based upon review of the data supporting the petition, EPA has revised the proposed tolerance on... for which there is reliable information.'' This includes exposure through drinking water and in...

Naphthalene Acetic Acid Potassium Salt (NAA-K+) Affects Conidial Germination, Sporulation, Mycelial Growth, Cell Surface Morphology, and Viability of Fusarium oxysporum f. sp. radici-lycopersici and F. oxysporum f. sp. cubense in Vitro.

PubMed

Manzo-Valencia, María Karina; Valdés-Santiago, Laura; Sánchez-Segura, Lino; Guzmán-de-Peña, Dora Linda

2016-11-09

The response to exogenous addition of naphthalene acetic acid potassium salt (NAA-K + ) to Fusarium oxysporum f. sp radici-lycopersici ATCC 60095 and F. oxysporum f. sp. cubense isolated from Michoacan Mexico soil is reported. The in vitro study showed that NAA-K + might be effective in the control of Fusarium oxysporum. Exogenous application of NAA-K + affected both spores and mycelium stages of the fungi. Viability testing using acridine orange and propidium iodide showed that NAA-K + possesses fungal killing properties, doing it effectively in the destruction of conidia of this phytopathogenic fungi. Analysis of treated spores by scanning electron microscopy showed changes in the shape factor and fractal dimension. Moreover, NAA-K + repressed the expression of brlA and fluG genes. The results disclosed here give evidence of the use of this synthetic growth factor as a substance of biocontrol that presents advantages, and the methods of application in situ should be explored.

In vitro Induction and Generation of Tetraploid Plants of Sophora tonkinensis Gapnep

PubMed Central

Wei, Kun Hua; Xu, Jian Ping; Li, Lin Xuan; Cai, Jin Yuan; Miao, Jian Hua; Li, Min Hui

2018-01-01

Background: Sophora tonkinensis Gapnep. is an important medical plant in China. Early researches of S. tonkinensis were focused on rapid propagation and quality analysis of in vitro tissue culture plantlet, and still no research focuses on the plant breeding of and there were no excellent varieties for artificial cultivation of S. tonkinensis. Objective: To set up a method to generate and select the best varieties of S. tonkinensis by polyploid breeding after induction by colchicine treatment. Materials and Methods: The adventitious buds were submerged in different concentrations of aqueous colchicine solution for different lengths of time to induce polyploidy in the plants, and the induced buds were identified by root-tip chromosome determination and leaf characteristics comparison. The contents of matrine and oxymatrine of radix ex rhizoma in 13 selected tetraploid lines were collected after 90 days in vitro rooting culture and were evaluated to provide evidence of good qualities of tetraploid S. tonkinensis. Results: The results showed that the highest percentage of tetraploid induction was 23.33% and occurred in the 0.2% (w/v) colchicine treatment for 30 h. Fifty lines of tetraploid plants were obtained and 12 of the 13 selected tetraploid lines exhibited higher productivity of total contents of matrine and oxymatrine when compared to controls. Conclusion: The data demonstrate that polyploidy induction can be beneficial for improving the medicinal value of S. tonkinensis. SUMMARY Colchicine has a good in vitro induction effect on the tetraploid plants of Sophora tonkinensisThe leaf indices and stomatal apparatus of tetraploid plants were slightly larger than diploid plantsThe total content of matrine and oxymatrine of some tetraploid lines for 90-day-old in vitro rooting culture was higher than the diploid. Abbreviations used: MS medium: Murashige and Skoog medium; BAP: 6-benzylaminopurine; NAA: A-naphthaleneacetic acid; IAA: Indole-3-acetic acid; KT: Kinetin; IBA: Indole-3-butyric acid; ABT: Rooting power. PMID:29720823

Hormonal induction and antihormonal inhibition of tracheary element differentiation in Zinnia cell cultures

NASA Technical Reports Server (NTRS)

Church, D. L.; Galston, A. W.

1988-01-01

Mechanically isolated mesophyll cells of Zinnia elegans L. cv Envy differentiate to tracheary elements when cultured in inductive medium containing sufficient auxin and cytokinin. Tracheary element differentiation was induced by the three auxins (alpha-naphthaleneacetic acid, indole-3-acetic acid, and 2,4-dichlorophenoxyacetic acid) and four cytokinins (6-benzyladenine, kinetin, 2-isopentenyladenine and zeatin) tested. Tracheary element formation is inhibited or delayed if the inductive medium is supplemented with an anticytokinin, antiauxin, or inhibitor of auxin transport.

Intra-trophic isotopic discrimination of 15N/14N for amino acids in autotrophs: Implications for nitrogen dynamics in ecological studies

USDA-ARS?s Scientific Manuscript database

Metabolic reactions within heterotrophs cause discrimination in their stable nitrogen isotopic composition of amino acids (d15NAA) compared to their diets. Ecologists have exploited this measurable inter-trophic discrimination in the d15NAA value to estimate the trophic positions of heterotrophic an...

Isatin as an auxin source favoring floral and vegetative shoot regeneration from calli produced by thin layer explants of tomato pedicel

NASA Technical Reports Server (NTRS)

Applewhite, P. B.; K-Sawhney, R.; Galston, A. W.

1994-01-01

Thin layer explants taken from the pedicels and peduncles of flowering tomato plants yielded calli with great organogenetic potential. Of the 15 cultivars tested, 7 regenerated roots, shoots and eventually entire fruit-bearing plants. Calli grown on modified Murashige-Skoog medium responded to varied auxins and cytokinins with different morphogenetic patterns. Thus, naphthaleneacetic acid yielded root-producing calli, while the auxin precursor isatin (indole 2,3-dione) caused the production of calli with vegetative and floral shoots, rarely yielding roots. This may be related to isatin's slow, steady conversion to an active auxin (Plant Physiol 41:1485-1488, 1966) in contrast with naphthaleneacetic acid's immediate presentation of a high level of active auxin. The highest incidence of vegetative shoot (100%) and flower (50%) formation was obtained with 10 micromoles isatin and 3 micromoles zeatin. A few of the flowers developed into ripe fruits. The high frequency of induction of vegetative shoots and flowers before roots with isatin suggests its utility in micropropagation from plant tissue cultures.

Parkinson's disease: in vivo metabolic changes in the frontal and parietal cortices in 6-OHDA treated rats during different periods.

PubMed

Hou, Zhongyu; Zhang, Zhonghe; Meng, Haiwei; Lin, Xiangtao; Sun, Bo; Lei, Hao; Fang, Ke; Fang, Fang; Liu, Maili; Liu, Shuwei

2014-02-01

This study aims to investigate metabolic changes in frontal and parietal cortices in the 6-OHDA induced Parkinson's rats. Ratios of N-acetyl-aspartic acid/creatine (NAA/Cr), choline/creatine (Cho/Cr), and glumatic acid and glutamine glutaminic acid/creatine (Glx/Cr) of regions of interests (ROIs) in the frontal and parietal cortices, and the substantia nigra were analyzed. NAA/Cr, Cho/Cr and Glx/Cr in the frontal and parietal cortices in the lesion side did not show any significant differences two weeks after operation compared with the contralateral side (p > 0.05). NAA/Cr in the frontal cortex in the lesion side was significantly lower in the five weeks after operation; Cho/Cr remained normal; Glx/Cr increased (p < 0.05), and all ratios of parietal cortex were normal. In the eight weeks after operation, NAA/Cr in the frontal cortex in the lesion side was lower than that of the five weeks (p < 0.01), Cho/Cr still remained normal while Glx/Cr was higher than before (p < 0.01). Regarding the parietal cortex, NAA/Cr increased significantly, while Cho/Cr and Glx/Cr remained normal. In the 12 weeks after operation, NAA/Cr, Cho/Cr and Glx/Cr in frontal cortex were consistent with that of the eight weeks, while they remained at the normal level in parietal cortex. The NAA/Cr in the substantia nigra decreased and Cho/Cr increased significantly during 2-8 weeks, and remained at the same level during 8-12 weeks. There are metabolic disturbances in PD rats. The transient hyperfunction in the parietal cortex can be considered as a compensation for the dysfunction of the frontal cortex and substantia nigra.

NAA-modified DNA oligonucleotides with zwitterionic backbones: stereoselective synthesis of A-T phosphoramidite building blocks.

PubMed

Schmidtgall, Boris; Höbartner, Claudia; Ducho, Christian

2015-01-01

Modifications of the nucleic acid backbone are essential for the development of oligonucleotide-derived bioactive agents. The NAA-modification represents a novel artificial internucleotide linkage which enables the site-specific introduction of positive charges into the otherwise polyanionic backbone of DNA oligonucleotides. Following initial studies with the introduction of the NAA-linkage at T-T sites, it is now envisioned to prepare NAA-modified oligonucleotides bearing the modification at X-T motifs (X = A, C, G). We have therefore developed the efficient and stereoselective synthesis of NAA-linked 'dimeric' A-T phosphoramidite building blocks for automated DNA synthesis. Both the (S)- and the (R)-configured NAA-motifs were constructed with high diastereoselectivities to furnish two different phosphoramidite reagents, which were employed for the solid phase-supported automated synthesis of two NAA-modified DNA oligonucleotides. This represents a significant step to further establish the NAA-linkage as a useful addition to the existing 'toolbox' of backbone modifications for the design of bioactive oligonucleotide analogues.

Compound-specific amino acid δ15N patterns in marine algae: Tracer potential for cyanobacterial vs. eukaryotic organic nitrogen sources in the ocean

NASA Astrophysics Data System (ADS)

McCarthy, Matthew D.; Lehman, Jennifer; Kudela, Raphael

2013-02-01

Stable nitrogen isotopic analysis of individual amino acids (δ15N-AA) has unique potential to elucidate the complexities of food webs, track heterotrophic transformations, and understand diagenesis of organic nitrogen (ON). While δ15N-AA patterns of autotrophs have been shown to be generally similar, prior work has also suggested that differences may exist between cyanobacteria and eukaryotic algae. However, δ15N-AA patterns in differing oceanic algal groups have never been closely examined. The overarching goals of this study were first to establish a more quantitative understanding of algal δ15N-AA patterns, and second to examine whether δ15N-AA patterns have potential as a new tracer for distinguishing prokaryotic vs. eukaryotic N sources. We measured δ15N-AA from prokaryotic and eukaryotic phytoplankton cultures and used a complementary set of statistical approaches (simple normalization, regression-derived fractionation factors, and multivariate analyses) to test for variations. A generally similar δ15N-AA pattern was confirmed for all algae, however significant AA-specific variation was also consistently identified between the two groups. The relative δ15N fractionation of Glx (glutamine + glutamic acid combined) vs. total proteinaceous N appeared substantially different, which we hypothesize could be related to differing enzymatic forms. In addition, the several other AA (most notably glycine and leucine) appeared to have strong biomarker potential. Finally, we observed that overall patterns of δ15N values in algae correspond well with the Trophic vs. Source-AA division now commonly used to describe variable AA δ15N changes with trophic transfer, suggesting a common mechanistic basis. Overall, these results show that autotrophic δ15N-AA patterns can differ between major algal evolutionary groupings for many AA. The statistically significant multivariate results represent a first approach for testing ideas about relative eukaryotic vs. prokaryotic ON sources in the sea.

N-acetyl-aspartate (NAA) as a correlate of pharmacological treatment in psychiatric disorders: a systematic review.

PubMed

Paslakis, Georgios; Träber, Frank; Roberz, Jens; Block, Wolfgang; Jessen, Frank

2014-10-01

The amino-acid N-acetyl-aspartate (NAA) is located in neurons and the concentration of NAA correlates with neuronal mitochondrial function. The signal of NAA, as measured with proton magnetic resonance spectroscopy (1H-MRS), is considered to reflect both, neuronal density and integrity of neuronal mitochondria. A reduction of the NAA concentrations has been found in several psychiatric disorders. Newer studies report reversal of decreased NAA concentration with treatment. The objective of this review is to summarize the literature on NAA changes in association with psychopharmacological treatment in psychiatric disorders (affective disorders, obsessive-compulsive disorder, schizophrenia and dementia). The majority of studies identified increased NAA concentrations in response to treatment, while a smaller number of studies did not find this effect. The NAA increase seems to be neither specific for a certain disorder nor for a specific intervention. This suggests that the reduction of NAA may represent an altered functional (metabolic) state of neurons common to different psychiatric disorders and the increase after treatment to indicate functional restoration as one general effect of interventions. Copyright © 2014 Elsevier B.V. and ECNP. All rights reserved.

Inactivation by Phenylglyoxal of the Specific Binding of 1-Naphthyl Acetic Acid with Membrane-Bound Auxin Binding Sites from Maize Coleoptiles

PubMed Central

Navé, Jean-François; Benveniste, Pierre

1984-01-01

The specific binding of 1-[3H]naphthyl acetic acid (NAA) to membrane-bound binding sites from maize (Zea mays cv INRA 258) coleoptiles is inactivated by phenylglyoxal. The inactivation obeys pseudo first-order kinetics. The rate of inactivation is proportional to phenylglyoxal concentration. Under conditions at which significant binding occurs, NAA, R and S-1-naphthyl 2-propionic acids protect the auxin binding site against inactivation by phenylglyoxal. Scatchard analysis shows that the inhibition of binding corresponds to a decrease in the concentration of sites but not in the affinity. The results of the present chemical modification study indicate that at least one arginyl residue is involved in the positively charged recognition site of the carboxylate anion of NAA. PMID:16663499

Posterior cingulate γ-aminobutyric acid and glutamate/glutamine are reduced in amnestic mild cognitive impairment and are unrelated to amyloid deposition and apolipoprotein E genotype

PubMed Central

Riese, Florian; Gietl, Anton; Zölch, Niklaus; Henning, Anke; O’Gorman, Ruth; Kälin, Andrea M.; Leh, Sandra E.; Buck, Alfred; Warnock, Geoffrey; Edden, Richard A.E.; Luechinger, Roger; Hock, Christoph; Kollias, Spyros; Michels, Lars

2017-01-01

The biomarker potential of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) for the in vivo characterization of preclinical stages in Alzheimer’s disease has not yet been explored. We measured GABA, glutamate + glutamine (Glx), and N-acetyl-aspartate (NAA) levels by single-voxel MEGA-PRESS magnetic resonance spectroscopy in the posterior cingulate cortex of 21 elderly subjects and 15 patients with amnestic mild cognitive impairment. Participants underwent Pittsburgh Compound B positron emission tomography, apolipoprotein E (APOE) genotyping, and neuropsychological examination. GABA, Glx, and NAA levels were significantly lower in patients. NAA was lower in Pittsburgh Compound B-positive subjects and APOE ε4 allele carriers. GABA, Glx, and NAA levels were positively correlated to CERAD word learning scores. Reductions in GABA, Glx, and NAA levels may serve as metabolic biomarkers for cognitive impairment in amnestic mild cognitive impairment. Because GABA and Glx do not seem to reflect amyloid β deposition or APOE genotype, they are less likely biomarker candidates for preclinical Alzheimer’s disease. PMID:25169676

Medial Frontal Lobe Neurochemistry in Autism Spectrum Disorder is Marked by Reduced N-Acetylaspartate and Unchanged Gamma-Aminobutyric Acid and Glutamate + Glutamine Levels.

PubMed

Carvalho Pereira, Andreia; Violante, Inês R; Mouga, Susana; Oliveira, Guiomar; Castelo-Branco, Miguel

2018-05-01

The nature of neurochemical changes in autism spectrum disorder (ASD) remains controversial. We compared medial prefrontal cortex (mPFC) neurochemistry of twenty high-functioning children and adolescents with ASD without associated comorbidities and fourteen controls. We observed reduced total N-acetylaspartate (tNAA) and total creatine, increased Glx/tNAA but unchanged glutamate + glutamine (Glx) and unchanged absolute or relative gamma-aminobutyric acid (GABA+) in the ASD group. Importantly, both smaller absolute and relative GABA+ levels were associated with worse communication skills and developmental delay scores assessed by the autism diagnostic interview-revised (ADI-R). We conclude that tNAA is reduced in the mPFC in ASD and that glutamatergic metabolism may be altered due to unbalanced Glx/tNAA. Moreover, GABA+ is related to autistic symptoms assessed by the ADI-R.

Syntheses, structural characterization, and DPPH radical scavenging activity of cocrystals of caffeine with 1- and 2-naphthoxyacetic acids

NASA Astrophysics Data System (ADS)

Suresh Kumar, G. S.; Seethalakshmi, P. G.; Sumathi, D.; Bhuvanesh, N.; Kumaresan, S.

2013-03-01

Caffeine:1-naphthoxyacetic acid [(caf)(1-naa)] and caffeine:2-naphthoxyacetic acid [(caf)(2-naa)] cocrystals have been synthesized and single crystals were grown by slow evaporation technique. The structures of the grown crystals were elucidated using single crystal X-ray diffraction analysis. Both the cocrystals belong to the monoclinic crystallographic system with space group P21/c, Z = 4, and α = γ = 90°, whereas β = 111.4244(18)° for [(caf)(1-naa)] and β = 109.281(6)° for [(caf)(2-naa)]. The crystal packing is predominantly stabilized by hydrogen bonding and π-π stacking interactions. The presence of unionized -COOH functional group in both the cocrystals was identified by FTIR spectral analysis. Thermal behavior and stability of both the cocrystals were studied by TGA/DTA analyses. Solvent-free formation of these cocrystals was confirmed by powder X-ray diffraction analyses. The theoretical energy of cocrystals showed that the formers have higher energy than cocrystals 1 and 2. DPPH radical scavenging activity of cocrystals 1 and 2 is slightly greater than the formers.

Aescin formation in calli and embryoids from cotyledon and stem explants of Aesculus hippocastanum L.

PubMed

Profumo, P; Caviglia, A M; Gastaldo, P

1994-11-01

Aescin in calli and embryoids obtained from both cotyledon and stem explants of Aesculus hippocastanum were investigated by HPLC. Determinations were carried out on tissues cultured in agarized medium supplemented with growth substances (2,4-dichlorophenoxyacetic acid; kinetin; 1-naphthaleneacetic acid). The results indicate that aescin was produced in all the analysed samples. The amount of active principle present in some samples was higher than that found in horse-chestnut seeds.

A multi-matrix HILIC-MS/MS method for the quantitation of endogenous small molecule neurological biomarker N-acetyl aspartic acid (NAA).

PubMed

Sangaraju, Dewakar; Shahidi-Latham, Sheerin K; Burgess, Braydon L; Dean, Brian; Ding, Xiao

2017-06-05

A multi-matrix hydrophilic interaction liquid chromatography tandem mass spectrometric method (HILIC-MS/MS) was developed for the quantitation of N-Acetyl Aspartic acid (NAA) using stable isotope labeled internal standard, D3-NAA in various biological matrices such as human plasma, human CSF, mouse plasma, brain and spinal cord. A high throughput 96-well plate format supported liquid extraction (SLE) procedure was developed and used for sample preparation. Mass spectrometric analysis of NAA was performed using selected reaction monitoring transitions in positive electrospray ionization mode. As NAA is endogenously present, a surrogate matrix approach was used for quantitation of NAA and the method was qualified over linear calibration curve range of 0.01-10μg/mL. Intra and inter assay precision indicated by percent relative standard deviation (%RSD) was less than 7.1% for low, medium, medium high and high QCs. The accuracy of the method ranged from 92.6-107.0% of nominal concentration for within-run and between-run for the same QCs. Extraction recovery of NAA and D3-NAA was greater than 76%. Stability of NAA was established in the above biological matrices under bench top (RT, 5h), freeze thaw (-20±10°C, 3 cycles) and moues/human plasma sample collection (Wet ice, RT) conditions. HILIC-MS/MS method was then used to quantify and compare the NAA levels in human plasma and CSF of ALS patients versus control human subjects. NAA CSF levels in control human subjects (73.3±31.0ng/mL,N=10) were found to be slightly higher than ALS patients (46.1±22.6ng/mL, N=10) (P=0.04). No differences were observed in NAA plasma levels in human control subjects (49.7±13.8ng/mL,N=9) as compared to ALS patients (49.6±8.1ng/mL, N=10) (P=0.983). NAA endogenous concentrations in mouse plasma, brain and spinal cord were found to be 243.8±56.8ng/mL (N=6), 1029.8±115.2μg/g tissue weight (N=5) and 487.6±178.4μg/g tissue weight (N=5) respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

A splice donor mutation in NAA10 results in the dysregulation of the retinoic acid signaling pathway and causes Lenz microphthalmia syndrome

PubMed Central

Esmailpour, Taraneh; Riazifar, Hamidreza; Liu, Linan; Donkervoort, Sandra; Huang, Vincent H; Madaan, Shreshtha; Shoucri, Bassem M; Busch, Anke; Wu, Jie; Towbin, Alexander; Chadwick, Robert B; Sequeira, Adolfo; Vawter, Marquis P; Sun, Guoli; Johnston, Jennifer J; Biesecker, Leslie G; Kawaguchi, Riki; Sun, Hui; Kimonis, Virginia; Huang, Taosheng

2014-01-01

Introduction Lenz microphthalmia syndrome (LMS) is a genetically heterogeneous X-linked disorder characterised by microphthalmia/anophthalmia, skeletal abnormalities, genitourinary malformations, and anomalies of the digits, ears, and teeth. Intellectual disability and seizure disorders are seen in about 60% of affected males. To date, no gene has been identified for LMS in the microphthalmia syndrome 1 locus (MCOPS1). In this study, we aim to find the disease-causing gene for this condition. Methods and results Using exome sequencing in a family with three affected brothers, we identified a mutation in the intron 7 splice donor site (c.471+2T→A) of the N-acetyltransferase NAA10 gene. NAA10 has been previously shown to be mutated in patients with Ogden syndrome, which is clinically distinct from LMS. Linkage studies for this family mapped the disease locus to Xq27-Xq28, which was consistent with the locus of NAA10. The mutation co-segregated with the phenotype and cDNA analysis showed aberrant transcripts. Patient fibroblasts lacked expression of full length NAA10 protein and displayed cell proliferation defects. Expression array studies showed significant dysregulation of genes associated with genetic forms of anophthalmia such as BMP4, STRA6, and downstream targets of BCOR and the canonical WNT pathway. In particular, STRA6 is a retinol binding protein receptor that mediates cellular uptake of retinol/vitamin A and plays a major role in regulating the retinoic acid signalling pathway. A retinol uptake assay showed that retinol uptake was decreased in patient cells. Conclusions We conclude that the NAA10 mutation is the cause of LMS in this family, likely through the dysregulation of the retinoic acid signalling pathway. PMID:24431331

Melatonin-stimulated biosynthesis of anti-microbial ZnONPs by enhancing bio-reductive prospective in callus cultures of Catharanthus roseus var. Alba.

PubMed

Riaz, Hafiza Rida; Hashmi, Syed Salman; Khan, Tariq; Hano, Christophe; Giglioli-Guivarc'h, Nathalie; Abbasi, Bilal Haider

2018-05-18

Melatonin as plant growth regulator induces differential effects on metabolites that are responsible for reduction, capping and stabilization of zinc oxide nanoparticles. Phytochemical analysis of callus cultures was performed and results were compared with callus cultures supplemented with other plant growth regulators (α-napthalene acetic acid, 2,4-dichlorophenoxy acetic acid and thidiazuron). Highest total phenolic and flavonoid content [42.23 mg of gallic acid equivalent (GAE) g -1 DW and 36.4 mg of (quercetin equivalent) g -1 DW, respectively] were recorded at melatonin (1.0 µM) + NAA (13.5 µM). ZnONPs were synthesized from NAA (13.5 µM) and melatonin (1.0 µM) + NAA (13.5 µM)-induced calli extracts separately and characterized via X-ray diffraction, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). FTIR analysis confirmed the presence of phenolics and flavonoids that were mainly found responsible for reduction and capping of ZnONPs. SEM analysis showed triangular shaped ZnONPs synthesized from melatonin + NAA callus extract and these NPs were more dispersed as compared to the spherical-agglomerates of ZnONPs synthesized from NAA-mediated callus extract. Melatonin + NAA callus extract-mediated ZnONPs (having smaller size) were more potent against multiple drug resistant bacterial strains, e.g. Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa by producing zone of inhibitions 17 ± 0.76 mm,10 ± 0.57 mm and 13 ± 0.54 mm, respectively.

A synthetic auxin (NAA) suppresses secondary wall cellulose synthesis and enhances elongation in cultured cotton fiber.

PubMed

Singh, Bir; Cheek, Hannah D; Haigler, Candace H

2009-07-01

Use of a synthetic auxin (naphthalene-1-acetic acid, NAA) to start (Gossypium hirsutum) ovule/fiber cultures hindered fiber secondary wall cellulose synthesis compared with natural auxin (indole-3-acetic acid, IAA). In contrast, NAA promoted fiber elongation and ovule weight gain, which resulted in larger ovule/fiber units. To reach these conclusions, fiber and ovule growth parameters were measured and cell wall characteristics were examined microscopically. The differences in fiber from NAA and IAA culture were underpinned by changes in the expression patterns of marker genes for three fiber developmental stages (elongation, the transition stage, and secondary wall deposition), and these gene expression patterns were also analyzed quantitatively in plant-grown fiber. The results demonstrate that secondary wall cellulose synthesis: (1) is under strong transcriptional control that is influenced by auxin; and (2) must be specifically characterized in the cotton ovule/fiber culture system given the many protocol variables employed in different laboratories.

Optimization of an efficient semi-solid culture protocol for sterilization and plant regeneration of Centella asiatica (L.) as a medicinal herb.

PubMed

Moghaddam, Sina Siavash; Jaafar, Hawa Binti; Aziz, Maheran Abdul; Ibrahim, Rusli; Rahmat, Asmah Bt; Philip, Elizabeth

2011-01-01

The present study investigates the effects of different concentrations, as well as type of plant growth regulators (PGRs) and medium (MS, Duchefa) on the growth and development of Centella asiatica in semi-solid culture. In addition, a protocol for successful sterilization of C.asiatica explants prepared from field-grown plants highly exposed to fungal and bacterial contamination was determined. Results for sterilization treatments revealed that applying HgCl₂ and Plant Preservative Mixture (PPM) with cetrimide, bavistin and trimethoprim which were included after washing with tap water, followed by the addition of PPM in the medium, produced a very satisfactory result (clean culture 90 ± 1.33%) and TS5 (decon + cetrimide 1% + bavistin 150 mg/L + trimethoprim 50 mg/L + HgCl₂0.1% + PPM 2% soak and 2 mL/L in medium) was hence chosen as the best method of sterilization for C.asiatica. The synergistic combination of 6 benzylaminopurine (BAP) and 1-naphthaleneacetic acid (NAA) in concentrations of 2 mg/L and 0.1 mg/L, respectively, in Duchefa medium compared with MS induced the most optimal percentage of sprouted shoots (93 ± 0.667), number of shoots (5.2 ± 0.079) and nodes (4 ± 0.067) per explant, leaf per explant (14 ± 0.107) and shoot length (4.1 ± 0.67 cm). Furthermore, optimum rooting frequency (95.2 ± 0.81%), the number of roots/shoot (7.5 ± 0.107) and the mean root length (4.5 ± 0.133 cm) occurred for shoots that were cultured on full-strength MS medium containing 0.5 mg/L indole-3-butyric acid (IBA). In this study, the acclimatized plantlets were successfully established with almost 85% survival. The findings of this study have proven an efficient medium and PGR concentration for the mass propagation of C.asiatica. These findings would be useful in micropropagation and ex situ conservation of this plant.

A 2,4-dichlorophenoxyacetic acid analog screened using a maize coleoptile system potentially inhibits indole-3-acetic acid influx in Arabidopsis thaliana

PubMed Central

Suzuki, Hiromi; Matano, Naoyuki; Nishimura, Takeshi; Koshiba, Tomokazu

2014-01-01

Studies using inhibitors of indole-3-acetic acid (IAA) transport, not only for efflux but influx carriers, provide many aspects of auxin physiology in plants. 1-Naphtoxyacetic acid (1-NOA), an analog of the synthetic auxin 1-N-naphtalene acetic acid (NAA), inhibits the IAA influx carrier AUX1. However, 1-NOA also shows auxin activity because of its structural similarity to NAA. In this study, we have identified another candidate inhibitor of the IAA influx carrier. The compound, “7-B3; ethyl 2-[(2-chloro-4-nitrophenyl)thio]acetate,” is a 2,4-dichlorophenoxyacetic acid (2,4-D) analog. At high concentrations (> 300 µM), 7-B3 slightly reduced IAA transport and tropic curvature of maize coleoptiles, whereas lower concentrations had almost no effect. We have analyzed the effects of 7-B3 on Arabidopsis thaliana seedlings. 7-B3 rescued the 2,4-D-inhibited root elongation, but not the NAA-inhibited root elongation. The effect of 7-B3 was weaker than that of 1-NOA. Both 1-NOA and 7-B3 inhibited DR5::GUS expression induced by IAA and 2,4-D, but not that induced by NAA. At high concentrations, 1-NOA exhibited auxin activity, but 7-B3 did not. Furthermore, 7-B3 inhibited apical hook formation in etiolated seedlings more effectively than 1-NOA did. These results indicate that 7-B3 is a potential inhibitor of IAA influx that has almost no effect on IAA efflux or auxin signaling. PMID:24800738

Extracellular N-Acetylaspartate in Human Traumatic Brain Injury

PubMed Central

Shannon, Richard J.; Carter, Eleanor L.; Jalloh, Ibrahim; Menon, David K.; Hutchinson, Peter J.; Carpenter, Keri L.H.

2016-01-01

Abstract N-acetylaspartate (NAA) is an amino acid derivative primarily located in the neurons of the adult brain. The function of NAA is incompletely understood. Decrease in brain tissue NAA is presently considered symptomatic and a potential biomarker of acute and chronic neuropathological conditions. The aim of this study was to use microdialysis to investigate the behavior of extracellular NAA (eNAA) levels after traumatic brain injury (TBI). Sampling for this study was performed using cerebral microdialysis catheters (M Dialysis 71) perfused at 0.3 μL/min. Extracellular NAA was measured in microdialysates by high-performance liquid chromatography in 30 patients with severe TBI and for comparison, in radiographically “normal” areas of brain in six non-TBI neurosurgical patients. We established a detailed temporal eNAA profile in eight of the severe TBI patients. Microdialysate concentrations of glucose, lactate, pyruvate, glutamate, and glycerol were measured on an ISCUS clinical microdialysis analyzer. Here, we show that the temporal profile of microdialysate eNAA was characterized by highest levels in the earliest time-points post-injury, followed by a steady decline; beyond 70 h post-injury, average levels were 40% lower than those measured in non-TBI patients. There was a significant inverse correlation between concentrations of eNAA and pyruvate; eNAA showed significant positive correlations with glycerol and the lactate/pyruvate (L/P) ratio measured in microdialysates. The results of this on-going study suggest that changes in eNAA after TBI relate to the release of intracellular components, possibly due to neuronal death or injury, as well as to adverse brain energy metabolism. PMID:26159566

Identification of endocannabinoid system-modulating N-alkylamides from Heliopsis helianthoides var. scabra and Lepidium meyenii.

PubMed

Hajdu, Zsanett; Nicolussi, Simon; Rau, Mark; Lorántfy, László; Forgo, Peter; Hohmann, Judit; Csupor, Dezső; Gertsch, Jürg

2014-07-25

The discovery of the interaction of plant-derived N-alkylamides (NAAs) and the mammalian endocannabinoid system (ECS) and the existence of a plant endogenous N-acylethanolamine signaling system have led to the re-evaluation of this group of compounds. Herein, the isolation of seven NAAs and the assessment of their effects on major protein targets in the ECS network are reported. Four NAAs, octadeca-2E,4E,8E,10Z,14Z-pentaene-12-ynoic acid isobutylamide (1), octadeca-2E,4E,8E,10Z,14Z-pentaene-12-ynoic acid 2'-methylbutylamide (2), hexadeca-2E,4E,9Z-triene-12,14-diynoic acid isobutylamide (3), and hexadeca-2E,4E,9,12-tetraenoic acid 2'-methylbutylamide (4), were identified from Heliopsis helianthoides var. scabra. Compounds 2-4 are new natural products, while 1 was isolated for the first time from this species. The previously described macamides, N-(3-methoxybenzyl)-(9Z,12Z,15Z)-octadecatrienamide (5), N-benzyl-(9Z,12Z,15Z)-octadecatrienamide (6), and N-benzyl-(9Z,12Z)-octadecadienamide (7), were isolated from Lepidium meyenii (Maca). N-Methylbutylamide 4 and N-benzylamide 7 showed submicromolar and selective binding affinities for the cannabinoid CB1 receptor (Ki values of 0.31 and 0.48 μM, respectively). Notably, compound 7 also exhibited weak fatty acid amide hydrolase (FAAH) inhibition (IC50 = 4 μM) and a potent inhibition of anandamide cellular uptake (IC50 = 0.67 μM) that was stronger than the inhibition obtained with the controls OMDM-2 and UCM707. The pronounced ECS polypharmacology of compound 7 highlights the potential involvement of the arachidonoyl-mimicking 9Z,12Z double-bond system in the linoleoyl group for the overall cannabimimetic action of NAAs. This study provides additional strong evidence of the endocannabinoid substrate mimicking of plant-derived NAAs and uncovers a direct and indirect cannabimimetic action of the Peruvian Maca root.

In vitro propagation of Gentiana scabra Bunge - an important medicinal plant in the Chinese system of medicines.

PubMed

Huang, Shih-Hung; Agrawal, Dinesh Chandra; Wu, Fang-Sheng; Tsay, Hsin-Sheng

2014-12-01

Gentiana scabra Bunge commonly known as 'Long dan cao' in China has been used in traditional Chinese medicines for more than 2000 years. Dry roots and rhizome of the herb have been used for the treatment of inflammation, anorexia, indigestion and gastric infections. Iridoids and secoiridoids are the main bioactive compounds which attribute to the pharmacological properties of this plant. The species is difficult to mass propagate by seed due to the low percentage of germination and limited dormancy period. Wild populations in some locations are considered to be in the endangered category due to over exploitation. In the present study, we report an efficient micropropagation system. Shoot apices of six weeks old in vitro grown G. scabra plants were used as explants for the in vitro propagation. Induction of multiple shoots (9.1/explant) was achieved on the culture of shoot apices on half strength Murashige and Skoog's basal medium (MSBM) containing 2.0 mg/L -1 6-benzylaminopurine (BA), 3% sucrose and 0.9% Difco agar. In vitro shoots induced profuse rooting on half strength of MSBM supplemented with 0.1 mg/L -1 1-naphthaleneacetic acid (NAA), 3% sucrose and 0.3% gelrite. A two-stage ventilation closure procedure during the in vitro culture, and transparent sachet technique enhanced the survival rate of G. scabra plantlets to 96% in the greenhouse. Tissue culture plants flowered after 5 months of transfer to pots. A simple and an efficient in vitro propagation protocol of Gentiana scabra Bunge by optimizing the medium composition and ventilation closure treatments has been developed. The protocol can be very useful in germplasm conservation and commercial cultivation of G. scabra plants.

Effect of Cd2+ and Cd2+/auxin mixtures on lipid monolayers - Model membrane studies on the role of auxins in phytoremediation of metal ions from contaminated environment.

PubMed

Hąc-Wydro, Katarzyna; Mach, Marzena; Węder, Karolina; Pająk, Katarzyna; Wydro, Paweł

2017-06-01

In this work Langmuir monolayer experiments were performed to analyze the effect of Cd 2+ ions and their mixtures with synthetic auxin (1-naphthaleneacetic acid - NAA) on lipid films. These investigations were motivated by the fact that auxins act effectively as the agents improving the removal of metal ions from contaminated water and soil by plants (phytoextraction), and although their mechanism of action in this area is still unclear, it was suggested that it can be membrane-related. The experiments were done for one component (1,2-dipalmitoyl-sn-glycero-3-phosphocholine - DPPC; 1,2-dioleoyl-sn-glycero-3-phosphocholine - DOPC; 1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (sodium salt) - DPPG) monolayers and mixed (DPPG/DOPC and DPPG/DPPC) films treated as model of plant leaves membranes. The monolayer properties were analyzed based on the surface pressure-area isotherms obtained during film compression, stability measurements and Brewster angle microcopy studies. The collected results together with the data presented in literature evidenced that both metal ions and auxins modify lipid system properties and by using them in a combination it is possible to weaken the influence of sole metal ions on membrane organization. This seems to be in agreement with the hypothesis that the role of plant growth regulators in increasing phytoextraction effectiveness may be membrane-related. However, further experiments are required to find possible correlations between the type and concentration of metal ion, composition of membrane or structural elements in auxin molecule and observed alterations in membrane properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Arbutin production via biotransformation of hydroquinone in in vitro cultures of Aronia melanocarpa (Michx.) Elliott.

PubMed

Kwiecień, Inga; Szopa, Agnieszka; Madej, Kornelia; Ekiert, Halina

2013-01-01

Arbutin (hydroquinone β-D-glucoside) is a compound of plant origin possessing valuable therapeutic (urinary tract disinfection) and cosmetic (skin whitening) properties, which can be obtained from in vitro cultures of plants belonging to different taxa via biotransformation of exogenously supplemented hydroquinone. Agitating cultures of Aronia melanocarpa were maintained on the Murashige and Skoog medium containing growth regulators: the cytokinin - BAP (6-benzylaminopurine), 2 mg/l and the auxin NAA (α-naphthaleneacetic acid), 2 mg/l. The biomass was cultured for 2 weeks and then hydroquinone was supplemented at the following doses: 96, 144, 192, 288 and 384 mg/l either undivided or divided into two or three portions added at 24-hour intervals. The content of the reaction product - arbutin, was determined using an HPLC method in methanolic extracts from biomass and lyophilized medium samples collected 24 hours after the addition of the last precursor dose. The total amounts of arbutin were very diverse, from 2.71 to 8.27 g/100g d.w. The production of arbutin rose with increasing hydroquinone concentration. The maximum content of the product was observed after hydroquinone addition at 384 mg/l divided into two portions. Biotransformation efficiency also varied widely, ranging from 37.04% do 73.80%. The identity of the product - arbutin, after its isolation and purification was confirmed by spectral analysis ((1)H-NMR spectrum). The maximum amount of arbutin obtained was higher than that required by the latest 9(th) Edition of the Polish Pharmacopoeia and by the newest 8th Edithion of European Pharmacopoeia for Uvae ursi folium (7.0 g/100g d.w.), and is interesting from practical point of view.

A germination bioassay as a toxicological screening system for studying the effects of potential prodrugs of naproxen.

PubMed

Gonzalez-de la Parra, M; Ramos-Mundo, C; Jimenez-Estrada, M; Ponce-de Leon, C; Castillo, R; Tejeda, V; Cuevas, K G; Enriquez, R G

1998-01-01

A germination bioassay with radish (Raphanus sativus L.) seeds was developed as a toxicological screening system for assessing the effects of new potential prodrugs of naproxen, as an alternative to animals and animal cell toxicity screens. Both enantiomers of naproxen (6-methoxy-α-methyl-2-naphthaleneacetic acid) and naproxol (6-methoxy-β-2-naphthaleneethanol), and their racemic mixtures, inhibited the radicle growth of R. sativus at a concentration of 1mM, while only (R)-(+ )-naproxol and racemic naproxol inhibited the hypocotyl growth of R. sativus at the same concentration. Four novel combinatorial esters, naproxen naproxyl esters (6-methoxy-β-methyl-2-naphthaleneethyl 6-methoxy-α-methyl-2-naphthaleneacetate), resulting from the combinatorial chemistry of the esterification reaction between naproxen and naproxol, were synthesised and then tested in the germination bioassay, at a concentration of 0.5mM. It was found that they did not inhibit either the radicle or the hypocotyl growth of R. sativus. 1998 FRAME.

Functionalized NaA nanozeolites labeled with 224,225Ra for targeted alpha therapy.

PubMed

Piotrowska, Agata; Leszczuk, Edyta; Bruchertseifer, Frank; Morgenstern, Alfred; Bilewicz, Aleksander

2013-01-01

The 223 Ra, 224 Ra, and 225 Ra radioisotopes exhibit very attractive nuclear properties for application in radionuclide therapy. Unfortunately the lack of appropriate bifunctional ligand for radium is the reason why these radionuclides have not found application in receptor-targeted therapy. In the present work, the potential usefulness of the NaA nanozeolite as a carrier for radium radionuclides has been studied. 224 Ra and 225 Ra, α-particle emitting radionuclides, have been absorbed in the nanometer-sized NaA zeolite (30-70 nm) through simple ion exchange. 224,225 Ra-nanozeolites exhibited very high stability in solutions containing physiological salt, EDTA, amino acids, and human serum. To make NaA nanozeolite particles dispersed in water their surface was modified with a silane coupling agent containing poly(ethylene glycol) molecules. This functionalization approach let us covalently attach a biomolecule to the NaA nanozeolite surface.

N-acetylaspartate (NAA) and N-acetylaspartylglutamate (NAAG) promote growth and inhibit differentiation of glioma stem-like cells.

PubMed

Long, Patrick M; Moffett, John R; Namboodiri, Aryan M A; Viapiano, Mariano S; Lawler, Sean E; Jaworski, Diane M

2013-09-06

Metabolic reprogramming is a pathological feature of cancer and a driver of tumor cell transformation. N-Acetylaspartate (NAA) is one of the most abundant amino acid derivatives in the brain and serves as a source of metabolic acetate for oligodendrocyte myelination and protein/histone acetylation or a precursor for the synthesis of the neurotransmitter N-acetylaspartylglutamate (NAAG). NAA and NAAG as well as aspartoacylase (ASPA), the enzyme responsible for NAA degradation, are significantly reduced in glioma tumors, suggesting a possible role for decreased acetate metabolism in tumorigenesis. This study sought to examine the effects of NAA and NAAG on primary tumor-derived glioma stem-like cells (GSCs) from oligodendroglioma as well as proneural and mesenchymal glioblastoma, relative to oligodendrocyte progenitor cells (Oli-Neu). Although the NAA dicarboxylate transporter NaDC3 is primarily thought to be expressed by astrocytes, all cell lines expressed NaDC3 and, thus, are capable of NAA up-take. Treatment with NAA or NAAG significantly increased GSC growth and suppressed differentiation of Oli-Neu cells and proneural GSCs. Interestingly, ASPA was expressed in both the cytosol and nuclei of GSCs and exhibited greatest nuclear immunoreactivity in differentiation-resistant GSCs. Both NAA and NAAG elicited the expression of a novel immunoreactive ASPA species in select GSC nuclei, suggesting differential ASPA regulation in response to these metabolites. Therefore, this study highlights a potential role for nuclear ASPA expression in GSC malignancy and suggests that the use of NAA or NAAG is not an appropriate therapeutic approach to increase acetate bioavailability in glioma. Thus, an alternative acetate source is required.

Evidence that the tri-cellular metabolism of N-acetylaspartate functions as the brain's "operating system": how NAA metabolism supports meaningful intercellular frequency-encoded communications.

PubMed

Baslow, Morris H

2010-11-01

N-acetylaspartate (NAA), an acetylated derivative of L-aspartate (Asp), and N-acetylaspartylglutamate (NAAG), a derivative of NAA and L-glutamate (Glu), are synthesized by neurons in brain. However, neurons cannot catabolize either of these substances, and so their metabolism requires the participation of two other cell types. Neurons release both NAA and NAAG to extra-cellular fluid (ECF) upon stimulation, where astrocytes, the target cells for NAAG, hydrolyze it releasing NAA back into ECF, and oligodendrocytes, the target cells for NAA, hydrolyze it releasing Asp to ECF for recycling to neurons. This sequence is unique as it is the only known amino acid metabolic cycle in brain that requires three cell types for its completion. The results of this cycling are two-fold. First, neuronal metabolic water is transported to ECF for its removal from brain. Second, the rate of neuronal activity is coupled with focal hyperemia, providing stimulated neurons with the energy required for transmission of meaningful frequency-encoded messages. In this paper, it is proposed that the tri-cellular metabolism of NAA functions as the "operating system" of the brain, and is essential for normal cognitive and motor activities. Evidence in support of this hypothesis is provided by the outcomes of two human inborn errors in NAA metabolism.

Role of Protein Dimeric Interface in Allosteric Inhibition of N-Acetyl-Aspartate Hydrolysis by Human Aspartoacylase.

PubMed

Kots, Ekaterina D; Lushchekina, Sofya V; Varfolomeev, Sergey D; Nemukhin, Alexander V

2017-08-28

The results of molecular modeling suggest a mechanism of allosteric inhibition upon hydrolysis of N-acetyl-aspartate (NAA), one of the most abundant amino acid derivatives in brain, by human aspartoacylase (hAsp). Details of this reaction are important to suggest the practical ways to control the enzyme activity. Search for allosteric sites using the Allosite web server and SiteMap analysis allowed us to identify substrate binding pockets located at the interface between the subunits of the hAsp dimer molecule. Molecular docking of NAA to the pointed areas at the dimer interface predicted a specific site, in which the substrate molecule interacts with the Gly237, Arg233, Glu290, and Lys292 residues. Analysis of multiple long-scaled molecular dynamics trajectories (the total simulation time exceeded 1.5 μs) showed that binding of NAA to the identified allosteric site induced significant rigidity to the protein loops with the amino acid side chains forming gates to the enzyme active site. Application of the protein dynamical network algorithms showed that substantial reorganization of the signal propagation pathways of intersubunit communication in the dimer occurred upon allosteric NAA binding to the remote site. The modeling approaches provide an explanation to the observed decrease of the reaction rate of NAA hydrolysis by hAsp at high substrate concentrations.

Severity of experimental traumatic brain injury modulates changes in concentrations of cerebral free amino acids.

PubMed

Amorini, Angela Maria; Lazzarino, Giacomo; Di Pietro, Valentina; Signoretti, Stefano; Lazzarino, Giuseppe; Belli, Antonio; Tavazzi, Barbara

2017-03-01

In this study, concentrations of free amino acids (FAA) and amino group containing compounds (AGCC) following graded diffuse traumatic brain injury (mild TBI, mTBI; severe TBI, sTBI) were evaluated. After 6, 12, 24, 48 and 120 hr aspartate (Asp), glutamate (Glu), asparagine (Asn), serine (Ser), glutamine (Gln), histidine (His), glycine (Gly), threonine (Thr), citrulline (Cit), arginine (Arg), alanine (Ala), taurine (Tau), γ-aminobutyrate (GABA), tyrosine (Tyr), S-adenosylhomocysteine (SAH), l-cystathionine (l-Cystat), valine (Val), methionine (Met), tryptophane (Trp), phenylalanine (Phe), isoleucine (Ile), leucine (Leu), ornithine (Orn), lysine (Lys), plus N-acetylaspartate (NAA) were determined in whole brain extracts (n = 6 rats at each time for both TBI levels). Sham-operated animals (n = 6) were used as controls. Results demonstrated that mTBI caused modest, transient changes in NAA, Asp, GABA, Gly, Arg. Following sTBI, animals showed profound, long-lasting modifications of Glu, Gln, NAA, Asp, GABA, Ser, Gly, Ala, Arg, Citr, Tau, Met, SAH, l-Cystat, Tyr and Phe. Increase in Glu and Gln, depletion of NAA and Asp increase, suggested a link between NAA hydrolysis and excitotoxicity after sTBI. Additionally, sTBI rats showed net imbalances of the Glu-Gln/GABA cycle between neurons and astrocytes, and of the methyl-cycle (demonstrated by decrease in Met, and increase in SAH and l-Cystat), throughout the post-injury period. Besides evidencing new potential targets for novel pharmacological treatments, these results suggest that the force acting on the brain tissue at the time of the impact is the main determinant of the reactions ignited and involving amino acid metabolism. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

N-Acetylaspartate (NAA) and N-Acetylaspartylglutamate (NAAG) Promote Growth and Inhibit Differentiation of Glioma Stem-like Cells*

PubMed Central

Long, Patrick M.; Moffett, John R.; Namboodiri, Aryan M. A.; Viapiano, Mariano S.; Lawler, Sean E.; Jaworski, Diane M.

2013-01-01

Metabolic reprogramming is a pathological feature of cancer and a driver of tumor cell transformation. N-Acetylaspartate (NAA) is one of the most abundant amino acid derivatives in the brain and serves as a source of metabolic acetate for oligodendrocyte myelination and protein/histone acetylation or a precursor for the synthesis of the neurotransmitter N-acetylaspartylglutamate (NAAG). NAA and NAAG as well as aspartoacylase (ASPA), the enzyme responsible for NAA degradation, are significantly reduced in glioma tumors, suggesting a possible role for decreased acetate metabolism in tumorigenesis. This study sought to examine the effects of NAA and NAAG on primary tumor-derived glioma stem-like cells (GSCs) from oligodendroglioma as well as proneural and mesenchymal glioblastoma, relative to oligodendrocyte progenitor cells (Oli-Neu). Although the NAA dicarboxylate transporter NaDC3 is primarily thought to be expressed by astrocytes, all cell lines expressed NaDC3 and, thus, are capable of NAA up-take. Treatment with NAA or NAAG significantly increased GSC growth and suppressed differentiation of Oli-Neu cells and proneural GSCs. Interestingly, ASPA was expressed in both the cytosol and nuclei of GSCs and exhibited greatest nuclear immunoreactivity in differentiation-resistant GSCs. Both NAA and NAAG elicited the expression of a novel immunoreactive ASPA species in select GSC nuclei, suggesting differential ASPA regulation in response to these metabolites. Therefore, this study highlights a potential role for nuclear ASPA expression in GSC malignancy and suggests that the use of NAA or NAAG is not an appropriate therapeutic approach to increase acetate bioavailability in glioma. Thus, an alternative acetate source is required. PMID:23884408

Local and downstream effects of excitotoxic lesions in the rat medial prefrontal cortex on In vivo 1H-MRS signals.

PubMed

Roffman, J L; Lipska, B K; Bertolino, A; Van Gelderen, P; Olson, A W; Khaing, Z Z; Weinberger, D R

2000-04-01

The rat medial prefrontal cortex (mPFC) regulates subcortical dopamine transmission via projections to the striatum and ventral tegmental area. We used in vivo proton magnetic resonance spectroscopy (1H-MRS) at 4.7 T to determine whether excitotoxic lesions of the mPFC result in alterations of N-acetylaspartate (NAA), a marker of neuronal integrity, both locally and downstream in the striatum. Lesioned rats exhibited persistent reductions of NAA and other metabolites within the prefrontal cortex; selective reductions of NAA were seen in the striatum, but not in the parietal cortex. Consistent with earlier reports, lesioned rats exhibited a transient enhancement in amphetamine-induced hyperlocomotion. Prefrontal NAA losses correlated with lesion extent. In the striatum, while there was no change in tissue volume, expression of striatal glutamic acid decarboxylase-67 mRNA was significantly reduced. In vivo NAA levels thus appear sensitive to both local and downstream alterations in neuronal integrity, and may signal meaningful effects at cellular and behavioral levels.

A cluster of culture positive gonococcal infections but with false negative cppB gene based PCR.

PubMed

Lum, G; Freeman, K; Nguyen, N L; Limnios, E A; Tabrizi, S N; Carter, I; Chambers, I W; Whiley, D M; Sloots, T P; Garland, S M; Tapsall, J W

2005-10-01

To describe the prevalence and characteristics of isolates of Neisseria gonorrhoeae grown from urine samples that produced negative results with nucleic acid amplification assays (NAA) targeting the cppB gene. An initial cluster of culture positive, but cppB gene based NAA negative, gonococcal infections was recognised. Urine samples and suspensions of gonococci isolated over 9 months in the Northern Territory of Australia were examined using cppB gene based and other non-cppB gene based NAA. The gonococcal isolates were phenotyped by determining the auxotype/serovar (A/S) class and genotyped by pulsed field gel electrophoresis (PFGE). 14 (9.8%) of 143 gonococci isolated were of A/S class Pro(-/)Brpyut, indistinguishable on PFGE and negative in cppB gene based, but not other, NAA. This cluster represents a temporal and geographic expansion of a gonococcal subtype lacking the cppB gene with consequent loss of sensitivity of NAA dependent on amplification of this target. Gonococci lacking the cppB gene have in the past been more commonly associated with the PAU-/PCU- auxotype, a gonococcal subtype hitherto infrequently encountered in Australia. NAA based on the cppB gene as a target may produce false positive as well as false negative NAA. This suggests that unless there is continuing comparison with culture to show their utility, cppB gene based NAA should be regarded as suboptimal for use either as a diagnostic or supplemental assay for diagnosis of gonorrhoea, and NAA with alternative amplification targets should be substituted.

Oligodendrocytes Do Not Export NAA-Derived Aspartate In Vitro.

PubMed

I Amaral, Ana; Hadera, Mussie Ghezu; Kotter, Mark; Sonnewald, Ursula

2017-03-01

Oligodendroglial cells are known to de-acetylate the N-acetylaspartate (NAA) synthesized and released by neurons and use it for lipid synthesis. However, the role of NAA regarding their intermediary metabolism remains poorly understood. Two hypotheses were proposed regarding the fate of aspartate after being released by de-acetylation: (1) aspartate is metabolized in the mitochondria of oligodendrocyte lineage cells; (2) aspartate is released to the medium. We report here that aspartoacylase mRNA expression increases when primary rat oligodendrocyte progenitor cells (OPCs) differentiate into mature cells in culture. Moreover, characterising metabolic functions of acetyl coenzyme A and aspartate from NAA catabolism in mature oligodendrocyte cultures after 5 days using isotope-labelled glucose after 5-days of differentiation we found evidence of extensive NAA metabolism. Incubation with [1,6- 13 C]glucose followed by gas chromatography-mass spectrometry and high performance liquid chromatography analyses of cell extracts and media in the presence and absence of NAA established that the acetate moiety produced by hydrolysis of NAA does not enter mitochondrial metabolism in the form of acetyl coenzyme A. We also resolved the controversy concerning the possible release of aspartate to the medium: aspartate is not released to the medium by oligodendrocytes in amounts detectable by our methods. Therefore we propose that: aspartate released from NAA joins the cytosolic aspartate pool rapidly and takes part in the malate-aspartate shuttle, which transports reducing equivalents from glycolysis into the mitochondria for ATP production and enters the tricarboxylic acid cycle at a slow rate.

Effect of Naphthalene Acetic Acid on Adventitious Root Development and Associated Physiological Changes in Stem Cutting of Hemarthria compressa

PubMed Central

Zhang, Xin-Quan; Yang, Wen-Yu; Wan, Yan; Ma, Ying-Mei; Zhu, Yong-Qun; Peng, Yan; Huang, Lin-Kai

2014-01-01

In order to find a way to induce rooting on cuttings of Hemarthria compressa cv. Ya’an under controlled conditions, a project was carried out to study the effect of naphthalene acetic acid (NAA) on rooting in stem cuttings and related physiological changes during the rooting process of Hemarthria compressa. The cuttings were treated with five concentrations of NAA (0, 100, 200 300, 400 mg/l) at three soaking durations (10, 20, 30 minutes), and cuttings without treatment were considered as control. Samples were planted immediately into pots after treatment. IAA-oxidase (IAAO) activity, peroxidase (POD) activity and polyphenol oxidase (PPO) activity were determined after planting. Results showed that NAA had positive effect on rooting at the concentration of 200 mg/l compared to other concentrations at 30 days after planting (DAP). Among the three soaking durations, 20 minutes (min) of 200 mg/l NAA resulted in higher percentages of rooting, larger numbers of adventitious roots and heavier root dry weight per cutting. The lowest IAAO activity was obtained when soaked at 200 mg/l NAA for 20 min soaking duration. This was consistent with the best rooting ability, indicating that the lower IAAO activity, the higher POD activity and PPO activity could be used as an indicator of better rooting ability for whip grass cuttings and might serve as a good marker for rooting ability in cuttings. PMID:24595064

Influence of auxins combinations on accumulation of reserpine in the callus of Rauvolfia tetraphylla L.

PubMed

Anitha, S; Kumari, B D Ranjitha

2007-11-01

Reserpine is a monoterpene indole alkaloid used to treat hypertension because of its hypotensive property and psychiatric disorders because of its tranquilizing effect. Protocol has been standardized to enhance the synthesis of reserpine in leaf derived calli of Rauvolfia tetraphylla L. by adjusting the auxins combinations in the medium consisting of MS nutrient salts and B5 vitamins. Auxins such as naphthalene acetic acid (NAA), indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) were used in 1-5 microM concentration along with 9 microM concentration of 2,4 dichlorophenoxy acetic acid (2,4-D), which was found suitable for callus induction. The combination of (2,4-D) with NAA had been proved to accumulate maximum amount of reserpine followed by 2,4-D with IBA. The IAA with 2,4-D combination yielded very less amount of reserpine than the other combinations and 9 microM 2,4-D alone. The results suggest that there may be synergetic effect of NAA with 2,4-D and IBA with 2,4-D for increase in the biomass and reserpine accumulation and antagonistic effect of IAA with 2,4-D for the above said factors in the callus.

Sources and transformation of dissolved and particulate organic nitrogen in the North Pacific Subtropical Gyre indicated by compound-specific δ15N analysis of amino acids

NASA Astrophysics Data System (ADS)

Yamaguchi, Yasuhiko T.; McCarthy, Matthew D.

2018-01-01

This study explores the use of compound-specific nitrogen isotopes of amino acids (δ15NAA) of coupled dissolved and particulate organic nitrogen (DON, PON) samples as a new approach to examine relative sources, transformation processes, and the potential coupling of these two major forms of N cycle in the ocean water column. We measured δ15NAA distributions in high-molecular-weight dissolved organic nitrogen (HMW DON) and suspended PON in the North Pacific Subtropical Gyre (NPSG) from surface to mesopelagic depths. A new analytical approach achieved far greater δ15NAA measurement precision for DON than earlier work, allowing us to resolve previously obscured differences in δ15NAA signatures, both with depth and between ON pools. We propose that δ15N values of total hydrolysable amino acids (THAA) represents a proxy for proteinaceous ON δ15N values in DON and PON. Together with bulk δ15N values, this allows δ15N values and changes in bulk, proteinaceous, and ;other-N; to be directly evaluated. These novel measurements suggest three main conclusions. First, the δ15NAA signatures of both surface and mesopelagic HMW DON suggest mainly heterotrophic bacterial sources, with mesopelagic HMW DON bearing signatures of far more degraded material compared to surface material. These results contrast with a previous proposal that HMW DON δ15NAA patterns are essentially ;pre-formed; by cyanobacteria in the surface ocean, undergo little change with depth. Second, different δ15NAA values and patterns of HMW DON vs. suspended PON in the surface NPSG suggest that sources and cycling of these two N reservoirs are surpisingly decoupled. Based on molecular δ15N signatures, we propose a new hypothesis that production of surface HMW DON is ultimately derived from subsurface nitrate, while PON in the mixed layer is strongly linked to N2 fixation and N recycling. In contrast, the comparative δ15NAA signatures of HMW DON vs. suspended PON in the mesopelagic also suggest a possible PON source for some HMW DON in the mid-water column. Together, these results suggest that conversion of relatively labile ON to less labile DON by heterotrophic bacteria (a ;microbial nitrogen pump;) may be the key pathway for production and alteration of DON in both the surface and the mesopelagic oligotrophic ocean. Finally, in contrast to THAA, δ15N values of the other-N were substantially less affected by heterotrophic alteration, which may be consistent with a larger than expected contribution of amino sugars, or other less labile nitrogenous organic molecules.

Structural Engineering of Nanoporous Anodic Alumina Photonic Crystals by Sawtooth-like Pulse Anodization.

PubMed

Law, Cheryl Suwen; Santos, Abel; Nemati, Mahdieh; Losic, Dusan

2016-06-01

This study presents a sawtooth-like pulse anodization approach aiming to create a new type of photonic crystal structure based on nanoporous anodic alumina. This nanofabrication approach enables the engineering of the effective medium of nanoporous anodic alumina in a sawtooth-like manner with precision. The manipulation of various anodization parameters such as anodization period, anodization amplitude, number of anodization pulses, ramp ratio and pore widening time allows a precise control and fine-tuning of the optical properties (i.e., characteristic transmission peaks and interferometric colors) exhibited by nanoporous anodic alumina photonic crystals (NAA-PCs). The effect of these anodization parameters on the photonic properties of NAA-PCs is systematically evaluated for the establishment of a fabrication methodology toward NAA-PCs with tunable optical properties. The effective medium of the resulting NAA-PCs is demonstrated to be optimal for the development of optical sensing platforms in combination with reflectometric interference spectroscopy (RIfS). This application is demonstrated by monitoring in real-time the formation of monolayers of thiol molecules (11-mercaptoundecanoic acid) on the surface of gold-coated NAA-PCs. The obtained results reveal that the adsorption mechanism between thiol molecules and gold-coated NAA-PCs follows a Langmuir isotherm model, indicating a monolayer sorption mechanism.

Adding Sarcosine to Antipsychotic Treatment in Patients with Stable Schizophrenia Changes the Concentrations of Neuronal and Glial Metabolites in the Left Dorsolateral Prefrontal Cortex.

PubMed

Strzelecki, Dominik; Podgórski, Michał; Kałużyńska, Olga; Stefańczyk, Ludomir; Kotlicka-Antczak, Magdalena; Gmitrowicz, Agnieszka; Grzelak, Piotr

2015-10-15

The glutamatergic system is a key point in pathogenesis of schizophrenia. Sarcosine (N-methylglycine) is an exogenous amino acid that acts as a glycine transporter inhibitor. It modulates glutamatergic transmission by increasing glycine concentration around NMDA (N-methyl-d-aspartate) receptors. In patients with schizophrenia, the function of the glutamatergic system in the prefrontal cortex is impaired, which may promote negative and cognitive symptoms. Proton nuclear magnetic resonance (¹H-NMR) spectroscopy is a non-invasive imaging method enabling the evaluation of brain metabolite concentration, which can be applied to assess pharmacologically induced changes. The aim of the study was to evaluate the influence of a six-month course of sarcosine therapy on the concentration of metabolites (NAA, N-acetylaspartate; Glx, complex of glutamate, glutamine and γ-aminobutyric acid (GABA); mI, myo-inositol; Cr, creatine; Cho, choline) in the left dorso-lateral prefrontal cortex (DLPFC) in patients with stable schizophrenia. Fifty patients with schizophrenia, treated with constant antipsychotics doses, in stable clinical condition were randomly assigned to administration of sarcosine (25 patients) or placebo (25 patients) for six months. Metabolite concentrations in DLPFC were assessed with 1.5 Tesla ¹H-NMR spectroscopy. Clinical symptoms were evaluated with the Positive and Negative Syndrome Scale (PANSS). The first spectroscopy revealed no differences in metabolite concentrations between groups. After six months, NAA/Cho, mI/Cr and mI/Cho ratios in the left DLPFC were significantly higher in the sarcosine than the placebo group. In the sarcosine group, NAA/Cr, NAA/Cho, mI/Cr, mI/Cho ratios also significantly increased compared to baseline values. In the placebo group, only the NAA/Cr ratio increased. The addition of sarcosine to antipsychotic therapy for six months increased markers of neurons viability (NAA) and neurogilal activity (mI) with simultaneous improvement of clinical symptoms. Sarcosine, two grams administered daily, seems to be an effective adjuvant in the pharmacotherapy of schizophrenia.

Brain Creatine Elevation and NAA Reduction Indicates Neuronal Dysfunction in the Setting of Enhanced Glial Energy Metabolism in a Macaque Model of neuroAIDS

PubMed Central

Ratai, Eva-Maria; Annamalai, Lakshmanan; Burdo, Tricia; Joo, Chan-Gyu; Bombardier, Jeffrey P.; Fell, Robert; Hakimelahi, Reza; He, Julian; Lentz, Margaret R.; Campbell, Jennifer; Curran, Elizabeth; Halpern, Elkan F.; Masliah, Eliezer; Westmoreland, Susan. V.; Williams, Kenneth C.; González, R. Gilberto

2011-01-01

Proton magnetic resonance spectroscopy (1H MRS) has emerged as one of the most informative neuroimaging modalities for studying the effect of HIV infection in the brain, providing surrogate markers by which to assess disease progression and monitor treatment. Reductions in the level of N-Acetylaspartate (NAA) and NAA/creatine (NAA/Cr) are established markers of neuronal injury or loss. However, the biochemical basis of altered creatine levels in neuroAIDS is not well understood. This study used a rapid progression macaque model of neuroAIDS to elucidate the changes in creatine. As the disease progressed 1H MRS revealed a decrease in NAA, indicative of neuronal injury, and an increase in creatine yet to be elucidated. Subsequently, immunohistochemistry and stereology measures of decreased synaptophysin, microtubule-associated protein 2, and neuronal density confirmed neuronal injury. Furthermore, increases in ionized calcium binding adaptor molecule 1 and glial fibrillary acidic protein indicated microglial and astroglial activation, respectively. Given these data, elevated creatine may reflect enhanced high-energy phosphate turnover in highly metabolizing activated astrocytes and microglia. PMID:21381104

Determination of naphthalene-derived compounds in apples by ultra-high performance liquid chromatography-tandem mass spectrometry.

PubMed

Esparza, X; Moyano, E; Cosialls, J R; Galceran, M T

2013-06-11

Naphthylacetic acid, naphthyloxy acetic acid and naphthylacetamide belong to a group of synthetic substances known as "auxin-like" compounds which are used as growth regulators in vegetables and fruits due to their structure similarities with the indoleacetic acid, the most important plant auxin. This paper reports a selective, sensitive and fast ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the determination of naphthylacetamide (NAD) and the isomers (α and β) of naphthylacetic acid (NAA) and naphthyloxy acetic (NOA) acid in apple samples. A baseline separation between the respective isomers was achieved using an RP-Amide column with gradient elution. The UHPLC-MS/MS method developed, using electrospray and selected reaction monitoring (SRM) acquisition mode led to a reliable determination of these family of compounds in apple samples at low quantitation levels, down to 1.0 μg kg(-1) and 0.25 μg kg(-1) respectively. For confirmation of NAA accurate mass measurement is proposed giving at these conditions quantitation limits of 10 μg kg(-1) for this compound. The UHPLC-MS/MS method developed was used for the analysis of apple samples harvested in three different apple fields from Lleida (Spain) during the blooming period. NAD and NAA were found in samples collected during 4-5 weeks after application at concentrations between the quantification limits and 43 μg kg(-1) and 24 μg kg(-1), respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

1H-MR spectroscopy and diffusion tensor imaging of normal-appearing temporal white matter in patients with nasopharyngeal carcinoma after irradiation: initial experience.

PubMed

Xiong, Wei Feng; Qiu, Shi Jun; Wang, Hong Zhuo; Lv, Xiao Fei

2013-01-01

To detect radiation-induced changes of temporal lobe normal-appearing white mater (NAWM) following radiation therapy (RT) for nasopharyngeal carcinoma (NPC). Seventy-five H(1)-MR spectroscopy and diffusion-tensor imaging (DTI) examinations were performed in 55 patients before and after receiving fractionated radiation therapy (total dose; 66-75GY). We divided the dataset into six groups, a pre-RT control group and five other groups based on time after completion of RT. N-acetylaspartic acid (NAA)/choline (Cho), NAA/creatine (Cr), Cho/Cr, mean diffusibility (MD), functional anisotropy (FA), radial diffusibility (λ(⊥)), and axial diffusibility (λ(||)) were calculated. NAA/Cho and NAA/Cr decreased and λ(⊥) increased significantly within 1 year after RT compared with pre-RT. After 1 year, NAA/Cho, NAA/Cr, and λ(⊥) were not significantly different from pre-RT. In all post-RT groups, FA decreased significantly. λ(||) decreased within 9 months after RT compared with pre-RT, but was not significantly different from pre-RT more than 9 months after RT. DTI and H(1)-MR spectroscopy can be used to detect early radiation-induced changes of temporal lobe NAWM following radiation therapy for NPC. Metabolic alterations and water diffusion characteristics of temporal lobe NAWM in patients with NPC after RT were dynamic and transient. Copyright © 2012 Wiley Periodicals, Inc.

Optimization of adventitious root culture for production of biomass and secondary metabolites in Prunella vulgaris L.

PubMed

Fazal, Hina; Abbasi, Bilal Haider; Ahmad, Nisar

2014-11-01

Adventitious root cultures of Prunella vulgaris L. were established in shaking flask system for the production of biomass and secondary metabolites. Adventitious root cultures were induced from callus cultures obtained from leaf explants on solid Murashige and Skoog (MS) medium containing combination of 6-benzyladenine (BA; 1.0 mg l(-1)) and naphthalene acetic acid (NAA; 1.5 mg l(-1)). Thereafter, 0.49 g inoculum was transferred to liquid MS medium supplemented with different concentrations of NAA (0.5-2.0 mg l(-1)). Growth kinetics of adventitious roots was recorded with an interval of 7 days for 49 days period. Highest biomass accumulation (2.13 g/l) was observed in liquid medium containing 1.0 mg l(-1) NAA after 21 days of inoculation. However, other concentrations of NAA also showed similar accumulation pattern but the biomass gradually decreases after 49 days of inoculation. Adventitious roots were collected and dried for investigation of total phenolics (TP), total flavonoids (TF), and antioxidant activities. Higher TPC (0.995 GAE mg/g-DRB) and TFC (6.615 RE mg/g-DRB) were observed in 0.5 mg l(-1) NAA treated cultures. In contrast, higher antioxidant activity (83.53 %) was observed 1.5 mg l(-1) NAA treated cultures. These results are helpful in up scaling of root cultures into bioreactor for secondary metabolites production.

Naphthylacetic Acid and Tea Polyphenol Application Promote Biomass and Lipid Production of Nervonic Acid-Producing Microalgae.

PubMed

Xu, Feng; Fan, Yong; Miao, Fuhong; Hu, Guang-Rong; Sun, Juan; Yang, Guofeng; Li, Fu-Li

2018-01-01

Mychonastes afer HSO-3-1 is a potential producer of nervonic acid, which could be accumulated to 2-3% of dry cell weight. Improving the productivity of nervonic acid is critical to promote the commercialization of this product. In this study, 1-naphthylacetic acid (NAA) and tea polyphenol (TP) were selected as bioactive additives to stimulate the growth of M. afer . Supplementing NAA in the early growth stage and TP in the middle and late growth stage led to improved lipid accumulation in M. afer . The cultures supplemented with TP at the late growth stage maintained higher photosynthetic efficiency than the control groups without TP. Furthermore, the intracellular reactive oxygen species (ROS) accumulations in M. afer supplemented with 500 mg/L of TP was 63% lower than the control group. A linear relationship ( R 2 = 0.899) between the values of Fv/Fm and ROS accumulation was established. We hypothesize supplement of bioactive additives at different growth stage could promote the cell growth rate and nervonic acid productivity of M. afer by retrieving intracellular ROS level. Further analysis of photosynthetic system II (PSII) protein in M. afer cultured in presence of NAA and TP indicated the levels of D1 and D2 proteins, the core skeleton proteins of PSII, showed 33.3 and 25.6% higher than the control group. CP43 protein, a critical module in PSII repair cycle, decreased significantly. These implied that TP possesses the function of slowing down the damage of PSII by scavenging excess intracellular ROS.

Alkamid database: Chemistry, occurrence and functionality of plant N-alkylamides.

PubMed

Boonen, Jente; Bronselaer, Antoon; Nielandt, Joachim; Veryser, Lieselotte; De Tré, Guy; De Spiegeleer, Bart

2012-08-01

N-Alkylamides (NAAs) are a promising group of bioactive compounds, which are anticipated to act as important lead compounds for plant protection and biocidal products, functional food, cosmeceuticals and drugs in the next decennia. These molecules, currently found in more than 25 plant families and with a wide structural diversity, exert a variety of biological-pharmacological effects and are of high ethnopharmacological importance. However, information is scattered in literature, with different, often unstandardized, pharmacological methodologies being used. Therefore, a comprehensive NAA database (acronym: Alkamid) was constructed to collect the available structural and functional NAA data, linked to their occurrence in plants (family, tribe, species, genus). For loading information in the database, literature data was gathered over the period 1950-2010, by using several search engines. In order to represent the collected information about NAAs, the plants in which they occur and the functionalities for which they have been examined, a relational database is constructed and implemented on a MySQL back-end. The database is supported by describing the NAA plant-, functional- and chemical-space. The chemical space includes a NAA classification, according to their fatty acid and amine structures. The Alkamid database (publicly available on the website http://alkamid.ugent.be/) is not only a central information point, but can also function as a useful tool to prioritize the NAA choice in the evaluation of their functionality, to perform data mining leading to quantitative structure-property relationships (QSPRs), functionality comparisons, clustering, plant biochemistry and taxonomic evaluations. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Relationship of executive functioning deficits to N-acetyl aspartate (NAA) and gamma-aminobutyric acid (GABA) in youth with bipolar disorder.

PubMed

Huber, Rebekah S; Kondo, Douglas G; Shi, Xian-Feng; Prescot, Andrew P; Clark, Elaine; Renshaw, Perry F; Yurgelun-Todd, Deborah A

2018-01-01

Although cognitive deficits in bipolar disorder (BD) have been repeatedly observed, our understanding of these impairments at a mechanistic level remains limited. Few studies that investigated cognitive impairments in bipolar illness have examined the association with brain biochemistry. This pilot study utilized proton magnetic resonance spectroscopy ( 1 H-MRS) to evaluate the relationship between neurocognitive performance and brain metabolites in youth with BD. Thirty participants, twenty depressed BD participants and ten healthy comparison participants, ages 13-21, completed mood and executive function measures. 1 H-MRS data were also acquired from the anterior cingulate cortex (ACC) using two-dimensional (2D) J-resolved 1 H-MRS sequence. Proton metabolites including N-acetyl aspartate (NAA) and gamma-aminobutyric acid (GABA) were quantified for both groups. Participants with BD performed significantly lower on executive functioning measures than comparison participants. There were significant positive correlations between Wisconsin Card Sorting Test (WCST) performance and NAA (p < .001) and GABA (p < .01) in the ACC in bipolar youth, such that as WCST performance increased, both NAA and GABA levels increased. Small sample size and lack of control for medications. These findings build on previous observations of biochemical alterations associated with BD and indicate that executive functioning deficits in bipolar youth are correlated with NAA and GABA. These results suggest that cognitive deficits occur early in the course of illness and may reflect risk factors associated with altered neurochemistry. Further investigation of the relationship between brain metabolites and cognition in BD may lead to important information for developing novel, targeted interventions. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of Antioxidants, Amino Acids and Plant Growth Regulators on in vitro Propagation of Rosa centifolia.

PubMed

Akhtar, Gulzar; Jaskani, Muhammad Jafar; Sajjad, Yasar; Akram, Ahsan

2016-03-01

Rosa centifoliais commercially propagated by asexual means but in vitro propagation ensure the production of disease free and healthy plants and browning of explants creates hurdle in their multiplication. The aim was to reduce oxidative browning of shoots of R. centifolia in MS medium during in vitro propagation. Axillary buds of R. centifolia were sterilized with 70% ethyl alcohol for 4 min and 5% sodium hypochlorite for 2 min followed by three washing with sterilized double distilled water. In order to control oxidative browning, Ascorbic acid (100 mg.L -1 ), citric acid (100 mg.L -1 ) and activated charcoal (3 g.L -1 ) were used while to control withering of shoots, different concentrations (3.0 mg.L -1 , 6.0 mg.L -1 , 9.0 mg.L -1 ) of either glutamine, asparagine and proline were put into trial. Different concentrations of Benzyl aminopurine (BAP) and naphthalene acetic acid (NAA) were used for in vitro shoot and root formation. Minimum browning percentage (20%) was achieved in the presence of activated charcoal (3.0 g.L -1 ) and pretreatment of explants with running tap water. Asparagin (9.0 mg.L -1 ) produced maximum shooting (93%), minimum withering (6.67%), and it took longer period (27 days) for shoots to wither. BAP (3.0 mg.L -1 ) + NAA (0.5 mg.L -1 ) was produced the highest number of shoots (1.63), in a shortest periods (9 days). For root production, NAA (1.5 mg.L -1 ) + BAP (0.5 mg.L -1 ) reduced the time to 11 days with maximum number of roots (4.33) and root length (4.20 cm). The supplement of activated charcoal (3.0 g.L -1 ), a sparagin (9.0 mg.L -1 ) and combination of BAP and NAA in the MS medium is effective for in vitro propagation of R. centifolia.

In vitro propagation and analysis of secondary metabolites in Glossogyne tenuifolia (Hsiang-Ju) - a medicinal plant native to Taiwan.

PubMed

Chen, Chia-Chen; Chang, Hung-Chi; Kuo, Chao-Lin; Agrawal, Dinesh Chandra; Wu, Chi-Rei; Tsay, Hsin-Sheng

2014-12-01

Glossogyne tenuifolia Cassini (Hsiang-Ju in Chinese) is a perennial herb native to Penghu Islands, Taiwan. The herb is a traditional anti-pyretic and hepatoprotective used in Chinese medicine. Several studies on G. tenuifolia have demonstrated its pharmacological values of antioxidation, anti-inflammation, immunomodulation, and cytotoxicity on several human cancer cell lines. Active compounds, oleanolic acid and luteolin in G. tenuifolia are affected by several factors, including climatic change, pathogens and agricultural practices. Plant population of G. tenuifolia has been severely affected and reduced considerably in natural habitat due to the use of herbicides by farmers. Also, collection of plant material from the natural habitat is restricted to a few months in a year. Therefore, the objective of the present study was to develop an efficient micropropagation protocol for G. tenuifolia. The study also aimed to investigate the influence of in vitro growth environment on the active compounds in in vitro shoots, tissue culture raised greenhouse plants; compare the values with wild plants and commercially available crude drug. Half-strength MS (Murashige and Skoog) basal medium supplemented with 0.1 mg/L 6-benzyladenine (BA) and 0.1 mg/L α-naphthaleneacetic acid (NAA) induced the maximum average number of shoots (7.3) per shoot tip explant excised from in vitro grown seedlings. Induction of rooting in cent percent in vitro shoots with an average number of 6.6 roots/shoot was achieved on ½ strength MS medium supplemented with 3.0 mg/L indole-3-acetic acid (IAA). The rooted plantlets acclimatized successfully in the greenhouse with a 100% survival rate. HPLC analysis revealed that the quantity of oleanolic acid and luteolin in in vitro shoots, tissue culture plants in the greenhouse, wild type plants and commercial crude drug varied depending upon the source. The oleanolic acid and luteolin contents were found to be significantly higher (16.89 mg/g and 0.84 mg/g, respectively) in 3-month old tissue culture raised plants in greenhouse compared to commercially available crude drug (6.51 mg/g, 0.13 mg/g, respectively). We have successfully developed an in vitro propagation protocol for G. tenuifolia which can expedite its plant production throughout the year. The contents of oleanolic acid and luteolin in the tissue culture raised plants in the greenhouse were significantly higher than the marketed crude drug demonstrating the practical application of the tissue culture technology. These findings may be very useful in micropropagation, germplasm conservation and commercial cultivation of G. tenuifolia. So far, there is no published report on tissue culture propagation of this important medicinal plant species.

Accuracy of noninvasive quantification of brain NAA concentrations using PRESS sequence: verification in a swine model with external standard.

PubMed

Wu, R H; Lin, R; Li, H; Xiao, Z W; Rao, H B; Luo, W H; Guo, G; Huang, K; Zhang, X G; Lang, Z J

2005-01-01

The metabolite ratios had been employed in the field of MR spectroscopy (MRS) for a long period. The main drawback of metabolite ratio is that ratio results are not comparable with absolute metabolite concentration in vivo. The purpose of this study was to examine the accuracy of noninvasive quantification of brain N-acetylaspartate (NAA) concentrations using previously reported MR external standard method. Eight swine were scanned on a GE 1.5 T scanner with a standard head coil. The external standard method was utilized with a sphere filled with NAA, GABA, glutamine, glutamate, creatine, choline chloride, and myo-inositol. The position resolved spectroscopy (PRESS) sequence was used with TE=135 msec, TR=1500 msec, and 128 scan averages. The analysis of MRS was done with SAGE/IDL program. In vivo NAA concentration was obtained using the equation S=N * e(-TE/T₂) * [1-e(-TR/T₁). In vitro NAA concentration was measured by high performance liquid chromatography (HPLC). In the MRS group, the mean concentration of NAA was 10.03 plusmn 0.74 mmol/kg. In the HPLC group, the mean concentration of NAA was 9.22 plusmn 0.55 mmol/kg. There was no significant difference between the two groups (p = 0.46). However, slightly higher value was observed in the MRS group (7/8 swine), compared with HPLC group. The range of differences was between 0.02~2.05 mmol/kg. MRS external reference method could be more accurate than internal reference method. ¹H MRS does not distinguish between N-acetyl resonance frequencies and other N-acetylated amino acids.

Prefrontal NAA and Glx Levels in Different Stages of Psychotic Disorders: a 3T 1H-MRS Study.

PubMed

Liemburg, Edith; Sibeijn-Kuiper, Anita; Bais, Leonie; Pijnenborg, Gerdina; Knegtering, Henderikus; van der Velde, Jorien; Opmeer, Esther; de Vos, Annerieke; Dlabac-De Lange, Jozarni; Wunderink, Lex; Aleman, André

2016-02-23

H-Magnetic Resonance Spectroscopy ((1)H-MRS) can offer insights in various neuropathologies by measuring metabolite levels in the brain. In the current study we investigated the levels of glutamate + glutamine (Glx, neurotransmitter and precursor) and N-Acetyl Aspartate + glutamic acid (NAA + NAAG; neuronal viability) in the prefrontal cortex of patients with a psychotic disorder and people at Ultra High Risk (UHR) for psychosis. A (1)H-MRS spectrum was acquired in 31 patients with a recent onset psychotic disorder and 60 with a chronic state, 16 UHR patients and 36 healthy controls. Absolute metabolite levels were calculated using LCModel with a reference water peak. Groups were compared while taking into account age and partial volume effects. Moreover, we investigated associations with positive and negative symptoms, duration of illness, and antipsychotic treatment in patients. The most notable finding is that chronicity of schizophrenia was related to decreased levels of Glx and NAA. On the other hand, although on an exploratory note, UHR showed increased levels of prefrontal Glx and NAA levels with increasing age. Our results may indicate an initial Glx and NAA increase and subsequent decrease during illness progression that may be related to the neurotoxic effects of glutamate.

High frequency plant regeneration from leaf derived callus of high Δ9-tetrahydrocannabinol yielding Cannabis sativa L.

PubMed

Lata, Hemant; Chandra, Suman; Khan, Ikhlas A; Elsohly, Mahmoud A

2010-10-01

An efficient in vitro propagation protocol for rapidly producing Cannabis sativa plantlets from young leaf tissue was developed. Using gas chromatography-flame ionization detection (GC-FID), high THC yielding elite female clone of a drug-type CANNABIS variety (MX) was screened and its vegetatively propagated clones were used for micropropagation. Calli were induced from leaf explant on Murashige and Skoog medium supplemented with different concentrations (0.5, 1.0, 1.5, and 2.0 µM) of indole- 3-acetic acid (IAA), indole- 3- butyric acid (IBA), naphthalene acetic acid (NAA), and 2,4-dichlorophenoxy-acetic acid (2,4-D) in combination with 1.0 µM of thidiazuron (TDZ) for the production of callus. The optimum callus growth and maintenance was in 0.5 µM NAA plus 1.0 µM TDZ. The two-month-old calli were subcultured to MS media containing different concentrations of cytokinins (BAP, KN, TDZ). The rate of shoot induction and proliferation was highest in 0.5 µM TDZ. Of the various auxins (IAA, IBA, and NAA) tested, regenerated shoots rooted best on half strength MS medium (1/2 - MS) supplemented with 2.5 µM IBA. The rooted plantlets were successfully established in soil and grown to maturity with no gross variations in morphology and cannabinoids content at a survival rate of 95 % in the indoor growroom. © Georg Thieme Verlag KG Stuttgart · New York.

Trends in Testing for Mycobacterium tuberculosis Complex From US Public Health Laboratories, 2009-2013.

PubMed

Tyrrell, Frances; Stafford, Cortney; Yakrus, Mitchell; Youngblood, Monica; Hill, Andrew; Johnston, Stephanie

We investigated data from US public health laboratories funded through the Centers for Disease Control and Prevention's Tuberculosis Elimination and Laboratory Cooperative Agreement to document trends and challenges in meeting national objectives in tuberculosis (TB) laboratory diagnoses. We examined data on workload and turnaround time from public health laboratories' progress reports during 2009-2013. We reviewed methodologies, laboratory roles, and progress toward rapid detection of Mycobacterium tuberculosis complex through nucleic acid amplification (NAA) testing. We compared selected data with TB surveillance reports to estimate public health laboratories' contribution to national diagnostic services. During the study period, culture and drug susceptibility tests decreased, but NAA testing increased. Public health laboratories achieved turnaround time benchmarks for drug susceptibility tests at lower levels than for acid-fast bacilli smear and identification from culture. NAA positivity in laboratories among surveillance-reported culture-positive TB cases increased from 26.6% (2355 of 8876) in 2009 to 40.0% (2948 of 7358) in 2013. Public health laboratories provided an estimated 50.9% (4285 of 8413 in 2010) to 57.2% (4210 of 7358 in 2013) of culture testing and 88.3% (6822 of 7727 in 2011) to 94.4% (6845 of 7250 in 2012) of drug susceptibility tests for all US TB cases. Public health laboratories contribute substantially to TB diagnoses in the United States. Although testing volumes mostly decreased, the increase in NAA testing indicates continued progress in rapid M tuberculosis complex detection.

Mechanism of Indole-3-acetic Acid Conjugation

PubMed Central

Goren, Raphael; Bukovac, Martin J.; Flore, James A.

1974-01-01

Formation of indole-3-acetic acid-aspartate in detached primary leaves of cowpea (Vigna sinensis Endl.) floating on 14C-indole-3-acetic acid (3 μc; 3.15 μm, phosphate-citrate buffer, pH 4.75), almost doubled when leaves were pretreated with 31.5 μm12C-indole-3-acetic acid for 17 hr and then transferred to 14C-indole-3-acetic acid for 4 hours as compared with leaves preincubated in buffer only. When leaves were preincubated with ethylene (11.0 and 104 μl/l) instead of 12C-indole-3-acetic acid, no induction of indole-3-acetylaspartic acid formation was observed, and the rate of indole-3-acetylaspartic acid formation decreased as compared with control leaves. Rhizobitoxine (1.87 μm) inhibited indole-3-acetic acid-induced ethylene production but did not prevent the formation of indole-3-acetylaspartic acid. In view of the similarity of these results and those previously obtained with α-naphthaleneacetic acid, it is concluded that ethylene has no role in the auxin-induced indole-3-acetylaspartic acid formation in cowpea leaves. PMID:16658669

[Establishment of embryogenic cell suspension culture and plant regeneration of edible banana Musa acuminata cv. Mas (AA)].

PubMed

Wei, Yue-Rong; Huang, Xue-Lin; Li, Jia; Huang, Xia; Li, Zhe; Li, Xiao-Ju

2005-01-01

Conventional breeding for dual resistance of disease and pest of Musa cultivars remains a difficult endeavor, as the plant is polyploidic and high in sterility. Biotechnological techniques, eg., genetic engineering, in vitro mutation breeding, or protoplast fusion, may overcome the difficulties and improve the germplasm. Establishment of a stable embryogenic cell suspension (ECS) is a prerequisite for any of the biotechnological breeding methods. In this study an embryogenic cell suspension was established from immature male flower of Musa acuminata cv. Mas (AA), a popular commercial variety of banana in the South-East Asian region. After culture for 5-6 months on callus induction media, which consisted of MS salts, different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D), 4.1 micromol/L biotin, 5.7 micromol/L indoleacetic acid (IAA), 5.4 micromol/L naphthaleneacetic acid (NAA), other vitamins, 87 mmol/L sucrose, and solidified with 7 g/L agarose, meristematic globules and yellow, friable embryogenic cultures were induced from the explants of 1-15th row young floral hands of immature male flowers. Of the four treatments of 2,4-D, 9 micromol/L was the most effective on the callus induction, it transformed 40.96% and 7.45% of the cultivated male floral hands into callus and embryogenic callus respectively. The explants to produce highest frequency of the embryogenic calli were floral hands of 6 to 12th rows, which generated 5.79% of the embryogenic calli. Suspension cultures were initiated from these embryogenic calli in liquid medium supplemented with 4.5 micromol/L 2, 4-D. After sieving selection of the cultures using a stainless steel metallic strainer with pore sizes of 154 microm at 15 day intervals for 3 months, homogeneous and yellow embryogenic cell suspensions, composed of single cells and small cell aggregates, were established. Based upon the growth quantity and growth rate of ECS, it was determined that the appropriate inoculum was 2.0 mL PCV ECS/30 mL medium in 100 mL flask, and the appropriate subculture cycle was 15 days. Planting of 6 months old ECS on semi-solid medium of somatic embryo induction and development (MSD) resulted in approximately 280 x 10(3) somatic embryos/mL PCV ECS. MSD contained SH macronutrients, micro-nutrients, Fe-EDTA and MS vitamins supplemented with 4.5 micromol/L biotin, 680 micromol/L glutamine, 2 mmol/L proline, 100 mg/L malt extract, 1.1 micromol/L NAA, 0.2 micromol/L zeatin, 0.5 micromol/L kinetin, 0.7 micromol/L N6-(2-isopentenyl) adenine, 29 mmol/L lactose, 130 mmol/L sucrose and solidified with 2g/L gelrite. After 3 months of maturity on MSD, 17.28% of the somatic embryos were germinated on germination media (MG), consisted of MS salt, Morel and Wetmore vitamins, 0.2 micromol/L 6-BA, 1.1 micromol/L IAA, 87 micromol/L sucrose and solidified with 2 g/L gelrite; and 14.16% of the somatic embryos could develop into normal plantlets on rooting media contained the same composition as that of MG but without auxin and cytokinin.

Factors Affecting the Accumulation of Curcumin in Microrhizomes of Curcuma aromatica Salisb

PubMed Central

Zhang, Xiaoxia; Sun, Shulan; Wang, Xiaojing

2015-01-01

Curcuminoids, and mainly curcumin, are potential therapeutic agents for the prevention of various diseases; however, little is known about the factors that influence their accumulation in Curcuma species. In this study, the effects of factors such as sucrose concentration, different ratios of 6-benzylaminopurine (6-BA) and α-naphthalene acetic acid (NAA), and light quality on the accumulation of curcumin and other curcuminoids in Curcuma aromatica were investigated. Microrhizomes grown on media containing 3% sucrose produced more curcumin and other curcuminoids than those grown on higher concentrations. Moreover, when compared to other ratios of 6-BA and NAA, microrhizomes induced on 3% sucrose media supplemented with 3.0 mg/L 6-BA and 0.5 mg/L NAA produced more curcumin and other curcuminoids; however, the amount was less than in microrhizomes grown on 3% sucrose alone. We determined that a 5% sucrose medium supplemented with 3.0 mg/L of 6-BA and 0.5 mg/L of NAA enhanced the levels of curcumin and curcuminoids and that exposure to red light further increased production. PMID:25722985

Factors affecting the accumulation of curcumin in microrhizomes of Curcuma aromatica Salisb.

PubMed

Wu, Ke; Zhang, Xiaoxia; Sun, Shulan; Wang, Xiaojing

2015-01-01

Curcuminoids, and mainly curcumin, are potential therapeutic agents for the prevention of various diseases; however, little is known about the factors that influence their accumulation in Curcuma species. In this study, the effects of factors such as sucrose concentration, different ratios of 6-benzylaminopurine (6-BA) and α-naphthalene acetic acid (NAA), and light quality on the accumulation of curcumin and other curcuminoids in Curcuma aromatica were investigated. Microrhizomes grown on media containing 3% sucrose produced more curcumin and other curcuminoids than those grown on higher concentrations. Moreover, when compared to other ratios of 6-BA and NAA, microrhizomes induced on 3% sucrose media supplemented with 3.0 mg/L 6-BA and 0.5 mg/L NAA produced more curcumin and other curcuminoids; however, the amount was less than in microrhizomes grown on 3% sucrose alone. We determined that a 5% sucrose medium supplemented with 3.0 mg/L of 6-BA and 0.5 mg/L of NAA enhanced the levels of curcumin and curcuminoids and that exposure to red light further increased production.

Regeneration of Acer caudatifolium Hayata plantlets from juvenile explants.

PubMed

Durkovic, J

2003-07-01

Juvenile and fully mature Acer caudatifolium Hayata explants were assayed for their organogenic capacity. A protocol for multiple shoot culture formation and in vitro plant regeneration was developed for juvenile axillary bud cultures. Mature explants failed in shoot regeneration. Shoot multiplication was achieved by releasing apical dominance of the single elongated shoot on woody plant medium (WPM) supplemented with 0.7 mg l(-1) 6-benzylaminopurine and 0.05 mg l(-1) alpha-naphthaleneacetic acid. The highest rooting percentage was recorded on half-strength WPM containing 1.0 mg l(-1) indole-3-butyric acid. Regenerated plantlets were successfully hardened to ex vitro conditions and continued to grow after transfer to soil. No morphological aberrations were observed in the regenerates.

Specific pretreatments reduce curing period of vanilla (Vanilla planifolia) beans.

PubMed

Sreedhar, R V; Roohie, K; Venkatachalam, L; Narayan, M S; Bhagyalakshmi, N

2007-04-18

With the aiming of reducing the curing period, effects of pretreatments on flavor formation in vanilla beans during accelerated curing at 38 degrees C for 40 days were studied. Moisture loss, change in texture, levels of flavoring compounds, and activities of relevant enzymes were compared among various pretreatments as well as the commercial sample. Use of naphthalene acetic acid (NAA; 5 mg/L) or Ethrel (1%) with blanching pretreatment resulted in 3-fold higher vanillin on the 10th day. Other flavoring compounds-vanillic acid, p-hydroxybenzoic acid, and p-hydroxybenzaldehyde-fluctuated greatly, showing no correlation with the pretreatments. Scarification of beans resulted in nearly 4- and 3.6-fold higher vanillin formations on the 10th day in NAA- and Ethrel-treated beans, respectively, as compared to control with a significant change in texture. When activities of major relevant enzymes were followed, addition of NAA or Ethrel helped to retain higher levels of cellulase throughout the curing period and higher levels of beta-glucosidase on the 20th day that correlated with higher vanillin content during curing and subsequent periods. Peroxidase, being highest throughout, did not correlate with the change in levels of major flavoring compounds. The pretreatment methods of the present study may find importance for realizing higher flavor formation in a shorter period because the major quality parameters were found to be comparable to those of a commercial sample.

Molecular dynamics simulations of the auxin-binding protein 1 in complex with indole-3-acetic acid and naphthalen-1-acetic acid.

PubMed

Grandits, Melanie; Oostenbrink, Chris

2014-10-01

Auxin-binding protein 1 (ABP1) is suggested to be an auxin receptor which plays an important role in several processes in green plants. Maize ABP1 was simulated with the natural auxin indole-3-acetic acid (IAA) and the synthetic analog naphthalen-1-acetic acid (NAA), to elucidate the role of the KDEL sequence and the helix at the C-terminus. The KDEL sequence weakens the intermolecular interactions between the monomers but stabilizes the C-terminal helix. Conformational changes at the C-terminus occur within the KDEL sequence and are influenced by the binding of the simulated ligands. This observation helps to explain experimental findings on ABP1 interactions with antibodies that are modulated by the presence of auxin, and supports the hypothesis that ABP1 acts as an auxin receptor. Stable hydrogen bonds between the monomers are formed between Glu40 and Glu62, Arg10 and Thr97, Lys39, and Glu62 in all simulations. The amino acids Ile22, Leu25, Trp44, Pro55, Ile130, and Phe149 are located in the binding pocket and are involved in hydrophobic interactions with the ring system of the ligand. Trp151 is stably involved in a face to end interaction with the ligand. The calculated free energy of binding using the linear interaction energy approach showed a higher binding affinity for NAA as compared to IAA. Our simulations confirm the asymmetric behavior of the two monomers, the stronger interaction of NAA than IAA and offers insight into the possible mechanism of ABP1 as an auxin receptor. © 2014 Wiley Periodicals, Inc.

[Impact of TDZ and NAA on adventitious bud induction and cluster bud multiplication in Tulipa edulis].

PubMed

Zhu, Li-Fang; Xu, Chao; Zhu, Zai-Biao; Yang, He-Tong; Guo, Qiao-Sheng; Xu, Hong-jian; Ma, Hong-Jian; Zhao, Gui-Hua

2014-08-01

To explore the method of explants directly induced bud and establish the tissue culture system of mutiple shoot by means of direct organogenesis, core bud and daughter bulbs (the top of bud stem expanded to form daughter bulb) of T. edulis were used as explants and treated with thidiazuron (TDZ) and 1-naphthlcetic acid (NAA). The results showed that the optimal medium for bud inducted form core bud and daughter bulb were MS + TDZ 2.0 mg x L(-1) + NAA 4.0 mg x L(-1) and MS +TDZ 2.0 mg x L(-1) + NAA 2.0 mg x L(-1) respectively, both of them had a bud induction rate of 72.92%, 79.22%. The optimal medium for cluster buds multiplication was MS + TDZ 0.2 mg x L(-1) + NAA 0.2 mg x L(-1), and proliferation coefficient was 2.23. After proliferation, cluster buds rooting occurred on MS medium with IBA 1.0 mg x L(-1) and the rooting rate was 52.6%, three to five seedlings in each plant. Using core bud and daughter bulb of T. edulis, the optimum medium for adventitious bud directly inducted from daughter bulb, core bud and cluster bud multiplication were screened out and the tissue culture system of multiple shoot by means of direct organogenesis was established.

Cytoplasmic Acidification and Secondary Metabolite Production in Different Plant Cell Suspensions (A Comparative Study).

PubMed Central

Hagendoorn, MJM.; Wagner, A. M.; Segers, G.; Van Der Plas, LHW.; Oostdam, A.; Van Walraven, H. S.

1994-01-01

In this study, a correlation is described between low cytoplasmic pH, measured with the fluorescent probes 2[prime],7[prime]-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (acetoxymethyl ester) and bis- [3-propyl-5-oxoisoxazol-4-yl]pentamethine oxonol, and the production of secondary metabolites for several plant cell-suspension systems. Anthraquinone production in Morinda citrifolia suspensions is negligible in the presence of 2,4-dichlorophenoxyacetic acid (2,4-D), whereas with naphthalene acetic acid (NAA) a significant accumulation is realized. NAA-grown cells showed a lower cytoplasmic pH than did 2,4-D-grown cells. Addition of 2,4-D or parachlorophenoxy acetic acid to NAA-grown cells resulted in an inhibition of anthraquinone production and an increase of the cytoplasmic pH, whereas addition of parachlorophenyl acetic acid had no effect on either parameter. Lignin production in Petunia hybrida cells could be induced by subculturing them in a medium without iron. These cells showed a lower cytoplasmic pH than control cells. Addition of Fe3+ led to a decreased lignin content and an increased cytoplasmic pH. Two cell lines of Linum flavum showed a different level of coniferin and lignin concentration in their cells. Cells that accumulated coniferin and lignin had a lower cytoplasmic pH than cells that did not accumulate these secondary metabolites. Apparently, in different species and after different kinds of treatment there is a correlation between acidification of the cytoplasm and the production of different secondary metabolites. The possible role of this acidification in secondary metabolite production is discussed. PMID:12232364

Cytoplasmic Acidification and Secondary Metabolite Production in Different Plant Cell Suspensions (A Comparative Study).

PubMed

Hagendoorn, MJM.; Wagner, A. M.; Segers, G.; Van Der Plas, LHW.; Oostdam, A.; Van Walraven, H. S.

1994-10-01

In this study, a correlation is described between low cytoplasmic pH, measured with the fluorescent probes 2[prime],7[prime]-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (acetoxymethyl ester) and bis- [3-propyl-5-oxoisoxazol-4-yl]pentamethine oxonol, and the production of secondary metabolites for several plant cell-suspension systems. Anthraquinone production in Morinda citrifolia suspensions is negligible in the presence of 2,4-dichlorophenoxyacetic acid (2,4-D), whereas with naphthalene acetic acid (NAA) a significant accumulation is realized. NAA-grown cells showed a lower cytoplasmic pH than did 2,4-D-grown cells. Addition of 2,4-D or parachlorophenoxy acetic acid to NAA-grown cells resulted in an inhibition of anthraquinone production and an increase of the cytoplasmic pH, whereas addition of parachlorophenyl acetic acid had no effect on either parameter. Lignin production in Petunia hybrida cells could be induced by subculturing them in a medium without iron. These cells showed a lower cytoplasmic pH than control cells. Addition of Fe3+ led to a decreased lignin content and an increased cytoplasmic pH. Two cell lines of Linum flavum showed a different level of coniferin and lignin concentration in their cells. Cells that accumulated coniferin and lignin had a lower cytoplasmic pH than cells that did not accumulate these secondary metabolites. Apparently, in different species and after different kinds of treatment there is a correlation between acidification of the cytoplasm and the production of different secondary metabolites. The possible role of this acidification in secondary metabolite production is discussed.

Potential of Different Coleus blumei Tissues for Rosmarinic Acid Production

PubMed Central

Vuković, Rosemary; Likić, Saša; Jelaska, Sibila

2015-01-01

Summary Rosmarinic acid is one of the main active components of Coleus blumei and is known to have numerous health benefits. The pharmacological significance of rosmarinic acid and its production through in vitro culture has been the subject of numerous studies. Here, the ability of different tissues to accumulate rosmarinic acid and sustainability in production over long cultivation have been tested. Calli, tumours, normal roots and hairy roots were established routinely by application of plant growth regulators or by transformation with agrobacteria. The differences among the established tumour lines were highly heterogeneous. Hairy root lines showed the highest mean growth rate and consistency in rosmarinic acid production. Although some tumour lines produced more rosmarinic acid than the hairy root lines, over a long cultivation period their productivity was unstable and decreased. Further, the effects of plant growth regulators on growth and rosmarinic acid accumulation were tested. 2,4-Dichlorophenoxyacetic acid significantly reduced tumour growth and rosmarinic acid production. 1-Naphthaleneacetic acid strongly stimulated hairy root growth whilst abscisic acid strongly enhanced rosmarinic acid production. Hairy roots cultured in an airlift bioreactor exhibited the highest potential for mass production of rosmarinic acid. PMID:27904326

Production of ajmalicine and ajmaline in hairy root cultures of Rauvolfia micrantha Hook f., a rare and endemic medicinal plant.

PubMed

Sudha, C G; Obul Reddy, B; Ravishankar, G A; Seeni, S

2003-04-01

Hairy roots of Rauvolfia micrantha were induced from hypocotyl explants of 2-3 weeks old aseptic seedlings using Agrobacterium rhizogenes ATCC 15834. Hairy roots grown in half-strength Murashige & Skoog (MS) medium with 0.2 mg indole 3-butyric acid l-1 and 0.1 mg alpha-naphthaleneacetic acid l-1 produced more ajmaline (0.01 mg g-1 dry wt) and ajmalicine (0.006 mg g-1 dry wt) than roots grown in auxin-free medium. Ajmaline (0.003 mg g-1 dry wt) and ajmalicine (0.0007 mg g-1 dry wt) were also produced in normal root cultures. This is the first report of production of ajmaline and ajmalicine in hairy root cultures of Rauvolfia micrantha.

In vitro propagation of the medicinal plant Ziziphora tenuior L. and evaluation of its antioxidant activity

PubMed Central

Dakah, Abdulkarim; Zaid, Salim; Suleiman, Mohamad; Abbas, Sami; Wink, Michael

2014-01-01

Ziziphora tenuior L. (Lamiaceae) is an aromatic herb used for its medicinal values against fungi, bacteria. Micropropagation can be used for large-scale multiplication of essential oil producing plants thus avoiding an overexploitation of natural resources. This work aims to develop a reliable protocol for the in vitro propagation of Z. tenuior, and to compare the antioxidant activity between in vitro propagated and wild plants. The explants were sterilized and cultured on MS medium containing different concentrations of growth regulators naphthalene acetic acid (NAA) or indole-3-butyric acid (IBA) with 0.5 mg/L of kinetin (Kin) callus formation was 70.2% after 45 days of incubation in dark on medium supplemented with 1.5 mg/L of NAA. After one month of callus culture on medium supplemented with 2 mg/L BA the shoot number was 5.12 and for the multiplication stage. The shoot number was 4.21 and length was 6.17 cm on medium supplemented with 1 mg/L Kin + 0.1 mg/L NAA. DPPH• reagent was used to test the antioxidant activity. The aqueous and methanol extracts of in vitro plants which were treated with 1.5 and 1 mg/L of kin plus 0.1 mg/L of NAA showed a strong DPPH• scavenging activity where IC50 was 0.307 and 0.369 mg/ml, respectively, while the IC50 of aqueous and methanol extracts of wild plants was 0.516 and 9.229 mg/ml, respectively. Our results suggested that plant growth regulators and in vitro culture conditions increased the antioxidant activity. PMID:25183942

In vitro propagation of the medicinal plant Ziziphora tenuior L. and evaluation of its antioxidant activity.

PubMed

Dakah, Abdulkarim; Zaid, Salim; Suleiman, Mohamad; Abbas, Sami; Wink, Michael

2014-09-01

Ziziphora tenuior L. (Lamiaceae) is an aromatic herb used for its medicinal values against fungi, bacteria. Micropropagation can be used for large-scale multiplication of essential oil producing plants thus avoiding an overexploitation of natural resources. This work aims to develop a reliable protocol for the in vitro propagation of Z. tenuior, and to compare the antioxidant activity between in vitro propagated and wild plants. The explants were sterilized and cultured on MS medium containing different concentrations of growth regulators naphthalene acetic acid (NAA) or indole-3-butyric acid (IBA) with 0.5 mg/L of kinetin (Kin) callus formation was 70.2% after 45 days of incubation in dark on medium supplemented with 1.5 mg/L of NAA. After one month of callus culture on medium supplemented with 2 mg/L BA the shoot number was 5.12 and for the multiplication stage. The shoot number was 4.21 and length was 6.17 cm on medium supplemented with 1 mg/L Kin + 0.1 mg/L NAA. DPPH• reagent was used to test the antioxidant activity. The aqueous and methanol extracts of in vitro plants which were treated with 1.5 and 1 mg/L of kin plus 0.1 mg/L of NAA showed a strong DPPH• scavenging activity where IC50 was 0.307 and 0.369 mg/ml, respectively, while the IC50 of aqueous and methanol extracts of wild plants was 0.516 and 9.229 mg/ml, respectively. Our results suggested that plant growth regulators and in vitro culture conditions increased the antioxidant activity.

Metabolite differences in the lenticular nucleus in type 2 diabetes mellitus shown by proton MR spectroscopy.

PubMed

Lin, Y; Zhou, J; Sha, L; Li, Y; Qu, X; Liu, L; Chen, H; An, Z; Wang, Y; Sun, C

2013-09-01

Previous studies by using proton MR spectroscopy found metabolite abnormalities in the cerebral cortex and white matter of patients with type 2 diabetes mellitus. The present study was undertaken to detect metabolite differences in the lenticular nuclei and thalamus in patients with T2DM. Twenty subjects with T2DM and 22 age-matched control subjects underwent single-voxel MR spectroscopy in the left and right lenticular nuclei and left and right thalami. NAA/Cr and Cho/Cr ratios were calculated. Brain lactic acid, fasting blood glucose, and glycosylated hemoglobin levels were also monitored. The NAA/Cr ratio was lower in the left lenticular nuclei of subjects with T2DM (P = .007), whereas the Cho/Cr ratio was increased in both the and right lenticular nuclei (P = .001). The NAA/Cr ratio was negatively correlated with FBG in the left (r = -0.573, P = .008) and right nuclei (r = -0.564, P = .010). It was also negatively correlated to HbA1c in the left (r = -0.560, P = .010) and right (r = -0.453, P = .045) nuclei. The Cho/Cr ratio was positively correlated with these variables (P < .05). No significant differences in NAA/Cr or Cho/Cr ratios were observed in the thalamus of patients with T2DM. Lactic acid was not detected in any of the patients in the study. The different metabolic statuses of the lenticular nuclei and thalamus suggest different effects of T2DM in each of these brain nuclei, with the lenticular nuclei being more vulnerable than the thalamus. The abnormal metabolic status was observed before lesions had appeared in these brain areas.

Grape berry ripening delay induced by a pre-véraison NAA treatment is paralleled by a shift in the expression pattern of auxin- and ethylene-related genes.

PubMed

Ziliotto, Fiorenza; Corso, Massimiliano; Rizzini, Fabio Massimo; Rasori, Angela; Botton, Alessandro; Bonghi, Claudio

2012-10-09

Auxins act as repressors of ripening inception in grape (véraison), while ethylene and abscisic acid (ABA) play a positive role as inducers of the syndrome. Despite the increasing amount of information made available on this topic, the complex network of interactions among these hormones remains elusive. In order to shed light on these aspects, a holistic approach was adopted to evaluate, at the transcriptomic level, the crosstalk between hormones in grape berries, whose ripening progression was delayed by applying naphtalenacetic acid (NAA) one week before véraison. The NAA treatment caused significant changes in the transcription rate of about 1,500 genes, indicating that auxin delayed grape berry ripening also at the transcriptional level, along with the recovery of a steady state of its intracellular concentration. Hormone indices analysis carried out with the HORMONOMETER tool suggests that biologically active concentrations of auxins were achieved throughout a homeostatic recovery. This occurred within 7 days after the treatment, during which the physiological response was mainly unspecific and due to a likely pharmacological effect of NAA. This hypothesis is strongly supported by the up-regulation of genes involved in auxin conjugation (GH3-like) and action (IAA4- and IAA31-like). A strong antagonistic effect between auxin and ethylene was also observed, along with a substantial 'synergism' between auxins and ABA, although to a lesser extent. This study suggests that, in presence of altered levels of auxins, the crosstalk between hormones involves diverse mechanisms, acting at both the hormone response and biosynthesis levels, creating a complex response network.

Amino acid nitrogen isotopic fractionation patterns as indicators of heterotrophy in plankton, particulate, and dissolved organic matter

NASA Astrophysics Data System (ADS)

McCarthy, Matthew D.; Benner, Ronald; Lee, Cindy; Fogel, Marilyn L.

2007-10-01

Bulk nitrogen (N) isotope signatures have long been used to investigate organic N source and food web structure in aquatic ecosystems. This paper explores the use of compound-specific δ 15N patterns of amino acids (δ 15N-AA) as a new tool to examine source and processing history in non-living marine organic matter. We measured δ 15N-AA distributions in plankton tows, sinking particulate organic matter (POM), and ultrafiltered dissolved organic matter (UDOM) in the central Pacific Ocean. δ 15N-AA patterns in eukaryotic algae and mixed plankton tows closely resemble those previously reported in culture. δ 15N differences between individual amino acids (AA) strongly suggest that the sharply divergent δ 15N enrichment for different AA with trophic transfer, as first reported by [McClelland, J.W. and Montoya, J.P. (2002) Trophic relationships and the nitrogen isotopic composition of amino acids. Ecology83, 2173-2180], is a general phenomenon. In addition, differences in δ 15N of individual AA indicative of trophic transfers are clearly preserved in sinking POM, along with additional changes that may indicate subsequent microbial reworking after incorporation into particles. We propose two internally normalized δ 15N proxies that track heterotrophic processes in detrital organic matter. Both are based on isotopic signatures in multiple AA, chosen to minimize potential problems associated with any single compound in degraded materials. A trophic level indicator (ΔTr) is derived from the δ 15N difference between selected groups of AA based on their relative enrichment with trophic transfer. We propose that a corresponding measure of the variance within a sub-group of AA (designated Σ V) may indicate total AA resynthesis, and be strongly tied to heterotrophic microbial reworking in detrital materials. Together, we hypothesize that ΔTr and Σ V define a two dimensional trophic "space", which may simultaneously express relative extent of eukaryotic and bacterial heterotrophic processing. In the equatorial Pacific, ΔTr indicates an average of 1.5-2 trophic transfers between phytoplankton and sinking POM at all depths and locations. The Σ V parameter suggests that substantial variation may exist in bacterial heterotrophic processing between differing regions and time periods. In dissolved material δ 15N-AA patterns appear unrelated to those in POM. In contrast to POM, δ 15N-AA signatures in UDOM show no clear changes with depth, and suggest that dissolved AA preserved throughout the oceanic water column have undergone few, if any, trophic transfers. Together these data suggest a sharp divide between processing histories, and possibly sources, of particulate vs. dissolved AA.

Somatic embryogenesis from leaf explants of Australian fan flower, Scaevola aemula R. Br.

PubMed

Wang, Y-H; Bhalla, P L

2004-01-01

Somatic embryogenesis from leaf explants of Scaevola aemula R. Br. was achieved. Somatic embryos were induced from explants cultured on MS medium supplemented with 0.2 mg/ 2,4-dichlorophenoxyacetic acid and 0.2-0.5 mg/l 6-benzylaminopurine (BAP). Various developmental stages of somatic embryos were found on this medium-from globular embryos to germinated embryos. The transfer of globular embryos to MS medium containing 0.5 mg/l BAP resulted in a high frequency of shoot regeneration. Leaf explants cultured on MS medium containing different combinations of BAP and alpha-naphthaleneacetic acid formed adventitious shoots and roots. Histological examination confirmed the process of somatic embryogenesis. Induction of somatic embryogenesis in Scaevola provides a system for studying embryogenesis in Australian native plants and will facilitate the improvement of these plants using genetic transformation techniques.

Factors affecting efficient in vitro micropropagation of Muscari muscarimi Medikus using twin bulb scale.

PubMed

Ozel, Cigdem Alev; Khawar, Khalid Mahmood; Unal, Fatma

2015-03-01

Endemic Muscari muscarimi Medikus is the most fragrant plant among Muscari species and has a high ornamental potential. The natural populations of M. muscarimi, are severely affected by increased environmental pollution and urbanization. There is a need to develop a micropropagation method that should serve effectively for commercial propagation and conservation. Therefore, the study targeted to set up a strategy for efficient in vitro bulblet regeneration system of M. muscarimi using twin scale bulb explants on 1.0 × MS medium containing 4.44, 8.88, 17.76 μM BAP (6-Benzylaminopurine) plus 2.685, 5.37, 10.74 μM NAA (α-Naphthalene acetic acid). Maximum number of 19 daughter axillary bulblets and 16 daughter adventitious bulblets per twin bulb scale explant was regenerated on 1.0 × MS medium containing 17.76 μM BAP plus 10.74 μM NAA and 17.76 μM BAP plus 2.685 μM NAA respectively. The daughter bulblets regenerated on twin bulb scales on 8 out of 9 regeneration treatment could be easily rooted on 1.0 × MS medium containing 4.9 μM IBA (Indole-3-butyric acid). The daughter bulblets regenerated on 9th treatment (1.0 × MS medium containing 17.76 μM BAP plus 10.74 μM NAA) were transferred to 1.0 × MS medium containing 30 g/l sucrose to break negative carry over effect of this dose of BAP-NAA, where they grew 2-3 roots of variable length. Daughter bulblet diameter was increased by culturing them on 1.0 × MS medium containing 4.44 μM BAP plus 5.37 μM NAA. The results verified that both age and the source of explants had significant effect on regeneration. In another set of experiments, twin scales were obtained from in vitro regenerated daughter bulblets, although they induced bulblets, yet their bulblet regeneration percentage, mean number of bulblets per explant and their diameter were significantly reduced. In vitro regenerated bulblets were acclimatized in growth chamber under ambient conditions of temperature and humidity on peat moss, where they flowered. The study provides important information about selection of suitable micropropagation medium, strategies to improve bulblet diameter and rooting of M. muscarimi which offers a scope for commercial propagation.

Factors affecting efficient in vitro micropropagation of Muscari muscarimi Medikus using twin bulb scale

PubMed Central

Ozel, Cigdem Alev; Khawar, Khalid Mahmood; Unal, Fatma

2014-01-01

Endemic Muscari muscarimi Medikus is the most fragrant plant among Muscari species and has a high ornamental potential. The natural populations of M. muscarimi, are severely affected by increased environmental pollution and urbanization. There is a need to develop a micropropagation method that should serve effectively for commercial propagation and conservation. Therefore, the study targeted to set up a strategy for efficient in vitro bulblet regeneration system of M. muscarimi using twin scale bulb explants on 1.0 × MS medium containing 4.44, 8.88, 17.76 μM BAP (6-Benzylaminopurine) plus 2.685, 5.37, 10.74 μM NAA (α-Naphthalene acetic acid). Maximum number of 19 daughter axillary bulblets and 16 daughter adventitious bulblets per twin bulb scale explant was regenerated on 1.0 × MS medium containing 17.76 μM BAP plus 10.74 μM NAA and 17.76 μM BAP plus 2.685 μM NAA respectively. The daughter bulblets regenerated on twin bulb scales on 8 out of 9 regeneration treatment could be easily rooted on 1.0 × MS medium containing 4.9 μM IBA (Indole-3-butyric acid). The daughter bulblets regenerated on 9th treatment (1.0 × MS medium containing 17.76 μM BAP plus 10.74 μM NAA) were transferred to 1.0 × MS medium containing 30 g/l sucrose to break negative carry over effect of this dose of BAP–NAA, where they grew 2–3 roots of variable length. Daughter bulblet diameter was increased by culturing them on 1.0 × MS medium containing 4.44 μM BAP plus 5.37 μM NAA. The results verified that both age and the source of explants had significant effect on regeneration. In another set of experiments, twin scales were obtained from in vitro regenerated daughter bulblets, although they induced bulblets, yet their bulblet regeneration percentage, mean number of bulblets per explant and their diameter were significantly reduced. In vitro regenerated bulblets were acclimatized in growth chamber under ambient conditions of temperature and humidity on peat moss, where they flowered. The study provides important information about selection of suitable micropropagation medium, strategies to improve bulblet diameter and rooting of M. muscarimi which offers a scope for commercial propagation. PMID:25737643

Inclusion of 1-naphthylacetic acid and 2-(1-naphthyl)acetamide into three typical multiresidue methods for LC/MS/MS analysis of tomatoes and zucchini.

PubMed

Lozano, Ana; Pérez-Parada, Andrés; Heinzen, Horacio; Fernández-Alba, Amadeo R

2012-01-01

In spite of high plant growth regulator application rates, little has been reported in the literature on determination of their residues in fruits and vegetables. This would be useful in monitoring good manufacturing practices and overall safety through the enforcement of maximum residue levels (MRLs). The present work describes method validation for the determination of 1-naphthylacetic acid (NAA) and 2(1-naphthyl)acetamide (NAAm) in tomato and zucchini using the mini-Luke, ethyl acetate (EtOAc) and acetate-buffered quick, easy, cheap, effective, rugged, and safe (QuEChERS) methods. Samples were spiked at two different levels: 50 and 100 pg/kg for NAA and 20 and 100 pg/kg for NAAm. These compounds were analyzed within the same chromatographic run with LC coupled to triple quadrupole MS (LC/(QqQ)MS/MS) in positive and negative electrospray ionization [ESI(+) and ESI(-)] modes for NAAm and NAA, respectively. For analyte confirmation, LC/ESI(-)QTOF-MS was also investigated given that NAA has only one multiple reaction monitoring transition (185.1-*140.9 m/z). These three common methods were used to determine linearity, recoveries, precision (RSD), matrix effects, repeatability, and reproducibility (n = 5) for the selected matrixes. In terms of the Directorate-General for Health and Consumers (DG-SANCO) guidelines, only insignificant differences were found for the multiresidue methods tested, regardless of the commodity. Matrix-matched calibration was used, and LODs were below 10.1 pg/kg for NAA and 6.0 pg/kg for NAAm, which were lower than the MRLs established in current European Union legislation for these compounds. Obtained recoveries for NAA ranged from 87 to 107% with RSD values below 10% for mini-Luke, 83 to 107% with RSD <11% for EtOAc, and 76 to 85% with RSD <7% for QuEChERS. NAAm recoveries ranged from 74 to 102% with RSD 5 15% for mini-Luke, 76 to 97% with RSD <4% for EtOAc, and 76 to 93% with RSD < 5% for QuEChERS. The linearity of the response over two orders of magnitude was demonstrated (r2 > 0.996) for all methods used. Good repeatability and reproducibility in terms of RSD were obtained (11.3-17.8%) for these analytical methods. The results were acceptable within the studied ranges for both analytes in all methods. As these multiresidue methods are used at the present time in many laboratories, this survey indicates that these analytes should be included in their monitoring scope.

Interactive Effects of Growth Regulators, Carbon Sources, pH on Plant Regeneration and Assessment of Genetic Fidelity Using Single Primer Amplification Reaction (SPARS) Techniques in Withania somnifera L.

PubMed

Fatima, Nigar; Ahmad, Naseem; Ahmad, Iqbal; Anis, Mohammad

2015-09-01

An improved and methodical in vitro shoot morphogenic approach through axillary bud multiplication was established in a drug yielding plant, Withania somnifera L. Effects of plant growth regulators [6-benzyladenine (BA), kinetin (Kin), 2-isopentenyladenine (2iP), and thidiazuron (TDZ)] either singly or in combination with α-napthalene acetic acid (NAA), indole-3-butyric acid (IBA), and indole-3-acetic acid (IAA) in Murashige and Skoog (MS) medium were tested. The highest regeneration frequency (90 %) with optimum number of shoots (32 ± 0.00)/explant were obtained on MS medium fortified with 2.5 μM 6-benzyladenine (BA) and 0.5 μM NAA and 30 g/l sucrose at pH 5.8. Among the tried TDZ concentrations, 0.5 μM resulted in maximum number of shoots (20.4 ± 0.40)/explant after 4 weeks of exposure. The proliferating shoot cultures established by repeated subculturing of the mother explants on the hormone-free medium produced the highest shoot number (29.4 ± 0.40) with shoot length (6.80 ± 0.12 cm)/explant at fourth subculture passage, which a decline in shoot proliferation was recorded. Different concentrations of NAA were tested for ex vitro rooting of microshoots. The maximum percentage of rooting 100 % with maximum roots (18.3 ± 0.1) was achieved in soilrite when basal portion of the microshoots were treated with 200 μM (NAA) for 15 min per shoot. The plantlets went through hardening phase in a growth chamber, prior to ex vitro transfer. The PCR-based single primer amplification reaction (SPAR) methods which include random amplified polymorphic DNA (RAPD) and direct amplification of minisatellite DNA (DAMD) markers has been used for assessment of genetic stability of micropropagated plantlets. No variation was observed in DNA fingerprinting patterns among the micropropagated and the donor plants illustrating their genetic uniformity.

In vitro regeneration of Drosera burmannii Vahl.: a carnivorous plant of north-east India.

PubMed

Yanthan, J Sureni; Kehie, Mechuselie; Kumaria, Suman; Tandon, Pramod

2017-06-01

An efficient in vitro regeneration protocol has been developed from shoot tips of Drosera burmannii Vahl., a carnivorous plant of north-east India. Various plant growth regulators were used to study their efficacy in the induction of multiple shoots and roots. Of the various treatments, the maximum number of shoots (28.8 ± 1.5) and roots (9.7 ± 0.6) was observed in one-fourth strength standard medium (MS with 50 mg/l citric acid and 10 mg/l ascorbic acid) supplemented with 4 mg/l 6-benzylaminopurine (BAP) and 4 mg/l α-naphthalene acetic acid (NAA) followed by 26.8 ± 1.4 shoots in one-fourth strength SM fortified with 4 mg/l kinetin (KN) and 4 mg/l NAA. The well-developed plantlets with shoots and roots were potted in small plastic glasses filled with a mixture of sand and farmyard manure (3:1); these plantlets when transferred to a glasshouse for hardening and acclimatization showed 90% survival.

Importance of single molecular determinants in the fidelity of expanded genetic codes.

PubMed

Antonczak, Alicja K; Simova, Zuzana; Yonemoto, Isaac T; Bochtler, Matthias; Piasecka, Anna; Czapinska, Honorata; Brancale, Andrea; Tippmann, Eric M

2011-01-25

The site-selective encoding of noncanonical amino acids (NAAs) is a powerful technique for the installation of novel chemical functional groups in proteins. This is often achieved by recoding a stop codon and requires two additional components: an evolved aminoacyl tRNA synthetase (AARS) and a cognate tRNA. Analysis of the most successful AARSs reveals common characteristics. The highest fidelity NAA systems derived from the Methanocaldococcus jannaschii tyrosyl AARS feature specific mutations to two residues reported to interact with the hydroxyl group of the substrate tyrosine. We demonstrate that the restoration of just one of these determinants for amino acid specificity results in the loss of fidelity as the evolved AARSs become noticeably promiscuous. These results offer a partial explanation of a recently retracted strategy for the synthesis of glycoproteins. Similarly, we reinvestigated a tryptophanyl AARS reported to allow the site-selective incorporation of 5-hydroxy tryptophan within mammalian cells. In multiple experiments, the enzyme displayed elements of promiscuity despite its previous characterization as a high fidelity enzyme. Given the many similarities of the TyrRSs and TrpRSs reevaluated here, our findings can be largely combined, and in doing so they reinforce the long-established central dogma regarding the molecular basis by which these enzymes contribute to the fidelity of translation. Thus, our view is that the central claims of fidelity reported in several NAA systems remain unproven and unprecedented.

Importance of single molecular determinants in the fidelity of expanded genetic codes

PubMed Central

Antonczak, Alicja K.; Simova, Zuzana; Yonemoto, Isaac T.; Bochtler, Matthias; Piasecka, Anna; Czapińska, Honorata; Brancale, Andrea; Tippmann, Eric M.

2011-01-01

The site-selective encoding of noncanonical amino acids (NAAs) is a powerful technique for the installation of novel chemical functional groups in proteins. This is often achieved by recoding a stop codon and requires two additional components: an evolved aminoacyl tRNA synthetase (AARS) and a cognate tRNA. Analysis of the most successful AARSs reveals common characteristics. The highest fidelity NAA systems derived from the Methanocaldococcus jannaschii tyrosyl AARS feature specific mutations to two residues reported to interact with the hydroxyl group of the substrate tyrosine. We demonstrate that the restoration of just one of these determinants for amino acid specificity results in the loss of fidelity as the evolved AARSs become noticeably promiscuous. These results offer a partial explanation of a recently retracted strategy for the synthesis of glycoproteins. Similarly, we reinvestigated a tryptophanyl AARS reported to allow the site-selective incorporation of 5-hydroxy tryptophan within mammalian cells. In multiple experiments, the enzyme displayed elements of promiscuity despite its previous characterization as a high fidelity enzyme. Given the many similarities of the TyrRSs and TrpRSs reevaluated here, our findings can be largely combined, and in doing so they reinforce the long-established central dogma regarding the molecular basis by which these enzymes contribute to the fidelity of translation. Thus, our view is that the central claims of fidelity reported in several NAA systems remain unproven and unprecedented. PMID:21224416

Diffusion tensor imaging and 1H-MRS study on radiation-induced brain injury after nasopharyngeal carcinoma radiotherapy.

PubMed

Wang, H-Z; Qiu, S-J; Lv, X-F; Wang, Y-Y; Liang, Y; Xiong, W-F; Ouyang, Z-B

2012-04-01

To investigate the metabolic characteristics of the temporal lobes following radiation therapy for nasopharyngeal carcinoma using diffusion tensor imaging (DTI) and proton magnetic resonance spectroscopy ((1)H-MRS). DTI and (1)H-MRS were performed in 48 patients after radiotherapy for nasopharyngeal carcinoma and in 24 healthy, age-matched controls. All patients and controls had normal findings on conventional MRI. Apparent diffusion coefficient (ADC), fractional anisotropy (FA), three eigenvalues λ1, λ2, λ3, N-acetylaspartic acid (NAA)/choline (Cho), NAA/creatinine (Cr), and Cho/Cr were measured in both temporal lobes. Patients were divided into three groups according to time after completion of radiotherapy: group 1, less than 6 months; group 2, 6-12 months; group 3, more than 12 months. Mean values for each parameter were compared using one-way analysis of variance (ANOVA). Mean FA in group 1 was significantly lower compared to group 3 and the control group (p < 0.05). Group-wise comparisons of apparent diffusion coefficient (ADC) values among all the groups were not significantly different. Eigenvalue λ1 was significantly lower in groups 1 and 3 compared to the control group (p < 0.05). NAA/Cho and NAA/Cr were significantly lower in each group compared to the control group (p < 0.01 for both). The decrease in NAA/Cho was greatest in group 1. There were no significant between-group differences regarding Cho/Cr. A combination of DTI and (1)H-MRS can be used to detect radiation-induced brain injury, in patients treated for nasopharyngeal carcinoma. Copyright © 2011 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Elicitation of Medicinally Important Antioxidant Secondary Metabolites with Silver and Gold Nanoparticles in Callus Cultures of Prunella vulgaris L.

PubMed

Fazal, Hina; Abbasi, Bilal Haider; Ahmad, Nisar; Ali, Mohammad

2016-11-01

Prunella vulgaris L. (P. vulgaris) is an important medicinal plant with a wide range of antiviral properties. Traditionally, it is known as self-heal because of its faster effects on wound healing. It is commonly known as a natural antiseptic due to the presence of various polyphenols. There is lack of research efforts on its propagation and production of bioactive compounds under field and in vitro conditions. In this study, the effects of different ratios (1:2, 1:3, 2:1, and 3:1) of silver (Ag) and gold (Au) nanoparticles (NPs) alone or in combination with naphthalene acetic acid (NAA) were investigated for callus culture development and production of secondary metabolites. The Ag (30 μg l -1 ), AgAu (1:2), and AgAu (2:1) NPs in combination with NAA (2.0 mg l -1 ) enhanced callus proliferation (100 %) as compared to the control (95 %). Among the different NPs tested, AuNPs with or without NAA produced higher biomass in log phases (35-42 days) of growth kinetics. Furthermore, AgAu (1:3) and AuNPs alone enhanced total protein content (855 μg-BSAE/mg-fresh weight (FW)), superoxide dismutase (0.54 nM/min/mg-FW), and peroxidase (0.39 nM/min/mg-FW) enzymes in callus cultures. The AgAuNPs (1:3) in combination with NAA induced maximum accumulation of phenolics (TPC 9.57 mg/g-dry weight (DW)) and flavonoid (6.71 mg/g-DW) content. Moreover, AgAuNPs (3:1) without NAA enhanced antioxidant activity (87.85 %). This study provides the first evidence of NP effect on callus culture development and production of natural antioxidants in P. vulgaris.

Acyl substrate preferences of an IAA-amido synthetase account for variations in grape (Vitis vinifera L.) berry ripening caused by different auxinic compounds indicating the importance of auxin conjugation in plant development.

PubMed

Böttcher, Christine; Boss, Paul K; Davies, Christopher

2011-08-01

Nine Gretchen Hagen (GH3) genes were identified in grapevine (Vitis vinifera L.) and six of these were predicted on the basis of protein sequence similarity to act as indole-3-acetic acid (IAA)-amido synthetases. The activity of these enzymes is thought to be important in controlling free IAA levels and one auxin-inducible grapevine GH3 protein, GH3-1, has previously been implicated in the berry ripening process. Ex planta assays showed that the expression of only one other GH3 gene, GH3-2, increased following the treatment of grape berries with auxinic compounds. One of these was the naturally occurring IAA and the other two were synthetic, α-naphthalene acetic acid (NAA) and benzothiazole-2-oxyacetic acid (BTOA). The determination of steady-state kinetic parameters for the recombinant GH3-1 and GH3-2 proteins revealed that both enzymes efficiently conjugated aspartic acid (Asp) to IAA and less well to NAA, while BTOA was a poor substrate. GH3-2 gene expression was induced by IAA treatment of pre-ripening berries with an associated increase in levels of IAA-Asp and a decrease in free IAA levels. This indicates that GH3-2 responded to excess auxin to maintain low levels of free IAA. Grape berry ripening was not affected by IAA application prior to veraison (ripening onset) but was considerably delayed by NAA and even more so by BTOA. The differential effects of the three auxinic compounds on berry ripening can therefore be explained by the induction and acyl substrate specificity of GH3-2. These results further indicate an important role for GH3 proteins in controlling auxin-related plant developmental processes.

Acyl substrate preferences of an IAA-amido synthetase account for variations in grape (Vitis vinifera L.) berry ripening caused by different auxinic compounds indicating the importance of auxin conjugation in plant development

PubMed Central

Böttcher, Christine; Boss, Paul K.; Davies, Christopher

2011-01-01

Nine Gretchen Hagen (GH3) genes were identified in grapevine (Vitis vinifera L.) and six of these were predicted on the basis of protein sequence similarity to act as indole-3-acetic acid (IAA)-amido synthetases. The activity of these enzymes is thought to be important in controlling free IAA levels and one auxin-inducible grapevine GH3 protein, GH3-1, has previously been implicated in the berry ripening process. Ex planta assays showed that the expression of only one other GH3 gene, GH3-2, increased following the treatment of grape berries with auxinic compounds. One of these was the naturally occurring IAA and the other two were synthetic, α-naphthalene acetic acid (NAA) and benzothiazole-2-oxyacetic acid (BTOA). The determination of steady-state kinetic parameters for the recombinant GH3-1 and GH3-2 proteins revealed that both enzymes efficiently conjugated aspartic acid (Asp) to IAA and less well to NAA, while BTOA was a poor substrate. GH3-2 gene expression was induced by IAA treatment of pre-ripening berries with an associated increase in levels of IAA-Asp and a decrease in free IAA levels. This indicates that GH3-2 responded to excess auxin to maintain low levels of free IAA. Grape berry ripening was not affected by IAA application prior to veraison (ripening onset) but was considerably delayed by NAA and even more so by BTOA. The differential effects of the three auxinic compounds on berry ripening can therefore be explained by the induction and acyl substrate specificity of GH3-2. These results further indicate an important role for GH3 proteins in controlling auxin-related plant developmental processes. PMID:21543520

Genetically Epilepsy-Prone Rats Have Increased Brain Regional Activity of an Enzyme Which Liberates Glutamate from N-acetyl-aspartyl-glutamate

DTIC Science & Technology

1992-01-01

DISTRIBUTION C OOt .APPROVED FOR PUPLIC RELEASE: DISTRIBUTION UNLIMITED Ii. A STRA T (Minls.m200oids N-Acetylated-a- 1 n (’ed acidic dip cpL,2ase (N...aspartate (NAA) and the excitatory amino acid , glutamate (CLU). Although there is evidence that NAAG might be a neurotransmitter, this dipoptide could...Genetics; Itippocampus: E-ctlsatlltmt pilepsy-, Glutamate: N-Acetylated-o-1 inked acidic dipeptidasc-: Enrniatic: IIrosz:NAAG: Aspartalc N-Acetylated-a

N-Acetylaspartate Metabolism Outside the Brain: Lipogenesis, Histone Acetylation, and Cancer

PubMed Central

Bogner-Strauss, Juliane G.

2017-01-01

N-acetylaspartate (NAA) is a highly abundant brain metabolite. Aberrant NAA concentrations have been detected in many pathological conditions and although the function of NAA has been extensively investigated in the brain it is still controversial. Only recently, a role of NAA has been reported outside the brain. In brown adipocytes, which show high expression of the NAA-producing and the NAA-cleaving enzyme, the metabolism of NAA has been implicated in lipid synthesis and histone acetylation. Increased expression of N-acetyltransferase 8-like (Nat8l, the gene encoding the NAA synthesizing enzyme) induces de novo lipogenesis and the brown adipocyte phenotype. Accordingly silencing of aspartoacylase, the NAA-cleaving enzyme, reduced brown adipocyte differentiation mechanistically by decreasing histone acetylation and gene transcription. Notably, the expression of Nat8l and the amount of NAA were also shown to be increased in several tumors and inversely correlate with patients’ survival. Additionally, Nat8l silencing reduced cell proliferation in tumor and non-tumor cells, while NAA supplementation could rescue it. However, the mechanism behind has not yet been clarified. It remains to be addressed whether NAA per se and/or its catabolism to acetate and aspartate, metabolites that have both been implicated in tumor growth, are valuable targets for future therapies. PMID:28979238

Establishment of the regeneration system for Vicia faba L.

PubMed

Bahgat, Shimaa; Shabban, Omer A; El-Shihy, Osama; Lightfoot, David A; El-Shemy, Hany A

2009-01-01

A reliable regeneration system for faba bean has been difficult to establish and therefore, the genetic improvement of Vicia faba L. was delayed. The paper describes a method of somatic embryo induction in callus of V. faba. Two Egyptian faba bean cultivars 'Giza 2' and '24 Hyto' were used. Callus was induced from epicotyls and shoot tips cultured on MS or Gamborg medium supplemented with 3% sucrose and 0.025% (w/v) for each of ascorbic and citric acid, 0.8% agar and different concentrations of 10 mg/l BAP, 0.5 mg/l of each NAA and 2,4-dichlorophenoxyacetic acid (M1) and 1 mg/l BAP and 0.5 mg/l NAA (M2) . The media with BAP, NAA and 2,4-D were optimal for embryogenic callus induction. Somatic embryos developed after transfer of the callus to 1/2 B5 medium with no plant growth regulators. There were various stages of somatic embryo development present including globular, heart-shaped, torpedo, and cotyledonary stages. Embryos developed into plantlets and plants were regenerated. RAPD analyses were performed to investigate the genetic stability of the regenerated plants obtained from different treatments and different explants. The cultivar Giza 2 exhibited more genetic stability than cultivar 24 Hyto. In conclusion, a regeneration system was established suitable for both gene transformation and the isolation of somaclonal mutants. The regeneration system will be used in order to improve the nutritional value of faba bean.

Establishment of an efficient in vitro regeneration protocol for rapid and mass propagation of Dendrobium chrysotoxum Lindl. using seed culture.

PubMed

Nongdam, Potshangbam; Tikendra, Leimapokpam

2014-01-01

An efficient in vitro regeneration protocol from seed culture has been established successfully for Dendrobium chrysotoxum, an epiphytic orchid having tremendous ornamental and medicinal values. Seed germination response was encouraging in Mitra (M) medium enriched with different combinations of auxins and cytokinins. Medium supplemented with 0.4% activated charcoal (AC), 2 mg/L 6-benzyl amino purine (BAP), and 2 mg/L indole-3-acetic acid (IAA) produced best seed germination percentage in 2 weeks of culture. Incorporation of higher concentration of kinetin (KN) or BAP in combination with low auxin in medium induced pronounced shooting and leaf formation. Reduction in leaf development was evident when cytokinins exist singly in medium indicating synergistic effect of auxin and cytokinin in leaf induction. Presence of elevated level of indole-3-butyric acid (IBA) or 1-naphthalene acetic acid (NAA) with low cytokinin content in medium generated more in vitro rooting, though IBA was found to be more effective in rooting induction as compared to NAA. The in vitro protocol for asymbiotic seed germination developed from the present investigation can be used for rapid mass propagation of this highly important Dendrobium orchid species.

Establishment of an Efficient In Vitro Regeneration Protocol for Rapid and Mass Propagation of Dendrobium chrysotoxum Lindl. Using Seed Culture

PubMed Central

2014-01-01

An efficient in vitro regeneration protocol from seed culture has been established successfully for Dendrobium chrysotoxum, an epiphytic orchid having tremendous ornamental and medicinal values. Seed germination response was encouraging in Mitra (M) medium enriched with different combinations of auxins and cytokinins. Medium supplemented with 0.4% activated charcoal (AC), 2 mg/L 6-benzyl amino purine (BAP), and 2 mg/L indole-3-acetic acid (IAA) produced best seed germination percentage in 2 weeks of culture. Incorporation of higher concentration of kinetin (KN) or BAP in combination with low auxin in medium induced pronounced shooting and leaf formation. Reduction in leaf development was evident when cytokinins exist singly in medium indicating synergistic effect of auxin and cytokinin in leaf induction. Presence of elevated level of indole-3-butyric acid (IBA) or 1-naphthalene acetic acid (NAA) with low cytokinin content in medium generated more in vitro rooting, though IBA was found to be more effective in rooting induction as compared to NAA. The in vitro protocol for asymbiotic seed germination developed from the present investigation can be used for rapid mass propagation of this highly important Dendrobium orchid species. PMID:25401154

Simultaneous determination of 13 phytohormones in oilseed rape tissues by liquid chromatography-electrospray tandem mass spectrometry and the evaluation of the matrix effect.

PubMed

Fan, Sufang; Wang, Xiupin; Li, Peiwu; Zhang, Qi; Zhang, Wen

2011-03-01

In the experiment, a high-performance liquid chromatography and electrospray ionization-tandem mass spectrometry with selected reaction monitoring was used to simultaneously determine various classes of phytohormones, including indole-3-acetic acid, α-naphthaleneacetic acid, 2-chlorobenzoic acid, 4-chlorobenzoic acid, indole-3-butyric acid, gibberellic acid, 2,4-dichlorophenoxyacetic acid, 2-naphthoxyacetic acid, abscisic acid, 2,3,5-triiodobenzoic acid, uniconazole, paclobutrazol and 2,4-epibassinolide in rape tissues. The analyses were separated by an HPLC equipped with a reversed-phase column using a binary solvent system composed of methanol and water, both containing 0.1% of formic acid. The matrix effect was also considered and determined. The technology was applied to analyze rape tissues, including roots, stems, leaves, flowers, immature pods and rape seeds. The rape tissues were subjected to ultrasound-assisted extraction and purified by dispersive solid-phase extraction, and then transferred into the liquid chromatography system. The detection limit for each plant hormone was defined by the ratio of signal/background noise (S/N) of 3. The results showed perfect linearity (R(2) values of 0.9987-1.0000) and reproducibility of elution times (relative standard deviations, RSDs,<1%) and peak areas (RSDs,<7%) for all target compounds. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Isolation of (S)-(+)-naproxene from Musa acuminata. Inhibitory effect of naproxene and its 7-methoxy isomer on constitutive COX-1 and inducible COX-2.

PubMed

Abad, T; McNaughton-Smith, G; Fletcher, W Q; Echeverri, F; Diaz-Peñate, R; Tabraue, C; Ruiz de Galarreta, C M; López-Blanco, F; Luis, J G

2000-06-01

The isolation and characterisation of (S)-(+)-6-methoxy-alpha-methyl-2-naphthaleneacetic acid, a well known synthetic non-steroidal anti-inflammatory drug (naproxene), from a natural source is described for the first time. We evaluated the ability of naproxene and its 7-methoxy isomer to abrogate constitutive COX-1 and inducible COX-2 activity in human A549 cells. Naproxene inhibited COX-1 (IC50 = 3.42 microM) and COX-2 (IC50 = 1.53 microM), whereas the 7-methoxy isomer had no appreciable effect on COX-1 (IC50 > 100 microM) but also abrogated the activity of COX-2 enzyme (IC50 = 14.42 microM).

Differential accumulation of hyperforin and secohyperforin in Hypericum perforatum tissue cultures.

PubMed

Charchoglyan, Armen; Abrahamyan, Arusyak; Fujii, Isao; Boubakir, Zakia; Gulder, Tobias A M; Kutchan, Toni M; Vardapetyan, Hrachik; Bringmann, Gerhard; Ebizuka, Yutaka; Beerhues, Ludger

2007-11-01

Hyperforin is a pharmacologically active constituent of Hypericum perforatum (St. John's wort). In vitro cultures of this medicinal plant were found to contain hyperforin and three related polyprenylated acylphloroglucinol derivatives. The accumulation of these compounds was coupled to shoot regeneration, with secohyperforin being the major constituent in morphogenic cultures. The structure of secohyperforin was elucidated online by LC-DAD, -MS, and -NMR. In multiple shoot cultures, the ratio of hyperforin to secohyperforin was strongly influenced by the phytohormones N6-benzylaminopurine (BAP) and naphthalene-1-acetic acid (NAA). While increasing concentrations of BAP stimulated the formation of hyperforin, increasing concentrations of NAA elevated the level of secohyperforin. No differential stimulation was observed after elicitor treatment. Hyperforin and secohyperforin are proposed to arise from a branch point in the biosynthetic pathway.

In Vitro Development from Leaf Explants of Sugar Beet (Beta vulgaris L). Rhizogenesis and the Effect of Sequential Exposure to Auxin and Cytokinin

PubMed Central

Gürel, Ekrem; Wren, M. Jill

1995-01-01

Adventitious root development in lamina and midrib-petiole junction expiants of sugar beet cv. Primo was investigated using scanning electron microscopy and light microscopy. Primordia developed close to the vascular strands and areas of newly dividing cells (meristematic centres) were seen adjacent to the intrafascicular cambium after 2 d incubation on medium containing 30 mg 1−11-naphthalene acetic acid. Clearly defined primordia were visible at 4 d and the first roots had emerged by 6 d. A minimum of 24 h exposure to NAA was necessary for root induction. Four days on NAA caused twice as many roots to be initiated but more prolonged exposure (5 and 10 d) inhibited root development. Root initiation continued after transfer to medium containing no plant growth regulators, new primordia appearing as the older ones extended as roots. Attempts were made to modify the development of primordia by sequential culture on cytokinin after induction by auxin. Incubation on N6-benzylaminopurine within 48 h of exposure to NAA disrupted the development of primordia and roots but did not induce shoot formation. PMID:21247910

In vitro plant regeneration of Aster scaber via somatic embryogenesis.

PubMed

Boo, Kyung Hwan; Cao, Dang Viet; Pamplona, Reniel S; Lee, Doseung; Riu, Key-Zung; Lee, Dong-Sun

2015-01-01

We established an in vitro plant regeneration system via somatic embryogenesis of Aster scaber, an important source of various biologically active phytochemicals. We examined the callus induction and embryogenic capacities of three explants, including leaves, petioles, and roots, on 25 different media containing different combinations of α-naphthalene acetic acid (NAA) and 6-benzyladenine (BA). The optimum concentrations of NAA and BA for the production of embryogenic calli were 5.0 μM and 0.05 μM, respectively. Media containing higher concentrations of auxin and cytokinin (such as 25 μM NAA and 25 μM BA) were suitable for shoot regeneration, especially for leaf-derived calli, which are the most readily available calli and are highly competent. For root induction from regenerated shoots, supplemental auxin and/or cytokinin did not improve rooting, but instead caused unwanted callus induction or retarded growth of regenerated plants. Therefore, plant growth regulator-free medium was preferable for root induction. Normal plants were successfully obtained from calli under the optimized conditions described above. This is the first report of the complete process of in vitro plant regeneration of A. scaber via somatic embryogenesis.

Reversal of metabolic deficits by lipoic acid in a triple transgenic mouse model of Alzheimer's disease: a 13C NMR study

PubMed Central

Sancheti, Harsh; Kanamori, Keiko; Patil, Ishan; Díaz Brinton, Roberta; Ross, Brian D; Cadenas, Enrique

2014-01-01

Alzheimer's disease is an age-related neurodegenerative disease characterized by deterioration of cognition and loss of memory. Several clinical studies have shown Alzheimer's disease to be associated with disturbances in glucose metabolism and the subsequent tricarboxylic acid (TCA) cycle-related metabolites like glutamate (Glu), glutamine (Gln), and N-acetylaspartate (NAA). These metabolites have been viewed as biomarkers by (a) assisting early diagnosis of Alzheimer's disease and (b) evaluating the efficacy of a treatment regimen. In this study, 13-month-old triple transgenic mice (a mouse model of Alzheimer's disease (3xTg-AD)) were given intravenous infusion of [1-13C]glucose followed by an ex vivo 13C NMR to determine the concentrations of 13C-labeled isotopomers of Glu, Gln, aspartate (Asp), GABA, myo-inositol, and NAA. Total (12C+13C) Glu, Gln, and Asp were quantified by high-performance liquid chromatography to calculate enrichment. Furthermore, we examined the effects of lipoic acid in modulating these metabolites, based on its previously established insulin mimetic effects. Total 13C labeling and percent enrichment decreased by ∼50% in the 3xTg-AD mice. This hypometabolism was partially or completely restored by lipoic acid feeding. The ability of lipoic acid to restore glucose metabolism and subsequent TCA cycle-related metabolites further substantiates its role in overcoming the hypometabolic state inherent in early stages of Alzheimer's disease. PMID:24220168

Biochemical composition of the alligator pipefish, Syngnathoides biaculeatus (Bloch, 1785)

NASA Astrophysics Data System (ADS)

Sanaye, Sushant Vilas; Pawar, Ashwini Pandurang; Rivonker, Chandrasheker Umanath; Sreepada, Rayadurga Anantha; Ansari, Zakir Ali; Ram, Anirudh

2017-11-01

Considering the economic importance in traditional Chinese medicine (TCM) and lack of baseline information, we evaluated the proximate composition, fatty acid and amino acid profiles, trace element content and C:N ratio in the alligator pipefish, Syngnathoides biaculeatus. Amongst proximate principals, a crude protein formed the major biochemical component ((58.9±2.2)% dry weight). Mean percent concentrations (dry weight) of other components such as a total lipid (TL), ash and nitrogen-free extract measured were, (1.8±0.2)%, (19.2±2.2)% and (20.1±0.45)%, respectively. The fatty acid profile revealed the presence of 27 saturated fatty acids (SFA) with 13 straight-chained and 14 branched-chained, 28 unsaturated fatty acids (UFA) with 14 monounsaturated and 14 polyunsaturated and nine other minor fatty acids. Mean percent contributions of total SFAs and UFAs to TL were found to be (55.41±0.24)% and (44.05±0.25)%, respectively. Altogether, 16 different amino acids with an equal number of essential (EAA) and non-essential (NAA) ones were identified. Percent contributions by EAA and NAA to the total amino acid content were 38.11% and 61.89%, respectively. Trace metal concentrations in S. biaculeatus were generally low and their distribution followed the order, Mg>Fe>Zn>Mn>Cu>Cr>Ni>Hg>Co. The C:N ratio was (4.37±0.04)%. The profile of major biochemical constituents in alligator pipefish, S. biaculeatus revealed its potential use in TCM as well as a nutritional diet for human consumption. The results of the study would also form the basis for formulation and optimization of diets for the culture of S. biaculeatus.

[Study of biological value of beef produced by interspecies hybrids of domestic cattle and wild yaks].

PubMed

Bagirov, V A; Chernukha, I M; Lisitsin, A V; Zinovieva, N A

2014-01-01

The comparative study of the chemical composition and biological values of beef produced by hybrids of Angus cattle with wild yaks (hybrid beef) and pure-bred Angus cattle (traditional beef) has been carried out. Longissimus muscle samples were used for analysis. It was observed, that the hybrid beef samples had the practically equal protein content comparing to traditional beef (21.1 vs. 21.6 per cent) but were characterized by the lower fat content (1.2 vs. 2.5 per cent). The higher biological value of hybrid beef comparing to traditional beef has been shown. The value of protein-quality index, calculated as the ratio of tryptophan amino acid to oxyprolin and characterizing the ratio of high biological value proteins to low biological value proteins was 8.1 vs. 5.7. The values of amino acid indexes [ratio of essential amino acids (EAA) to non-essential amino acids (NAA) and ratio of EAA to the total amount of amino acids (TAA)] were EAA/NAA = 0.77 vs. 0.65 and EAA/TAA = 0.43 vs. 0.39. The protein of hybrid beef was characterized by the higher content of a number of the essential amino acids: by a factor of 1, 77 for threonin, 1.23--for valin, 1.09--for lysin, 1.17--for leucine and 1.19--for tryptophan. The amount of the essential amino acids in 1 gram of protein of the hybrid beef was 434.7 mg against 393.1 mg for traditional beef It has been shown, that the protein of the hybrid beef comparing to traditional beef is characterized by the higher values of the amino acid scores calculated for EAA.

Association between Proton Magnetic Resonance Spectroscopy Measurements and CAG Repeat Number in Patients with Spinocerebellar Ataxias 2, 3, or 6

PubMed Central

Wang, Po-Shan; Chen, Hung-Chieh; Wu, Hsiu-Mei; Lirng, Jiing-Feng; Wu, Yu-Te; Soong, Bing-Wen

2012-01-01

The aim of this study was to correlate magnetic resonance spectroscopy (MRS) measurements, including that for the N-acetyl aspartate (NAA)/creatine (Cr) ratio in the vermis (denoted V-NAA), right cerebellar hemisphere (R-NAA), and left (L-NAA) cerebellar hemisphere, with the clinical scale for the assessment and rating of ataxia (SARA) score for patients with spinocerebellar ataxia (SCA) types 2, 3, and 6. A total of 24 patients with SCA2, 48 with SCA3, and 16 with SCA6 were recruited; 12 patients with SCA2, 43 with SCA3, and 8 with SCA6 underwent detailed magnetic resonance neuroimaging. Forty-four healthy, age-matched individuals without history of neurologic disease served as control subjects. V-NAA and patient age were used to calculate the predicted age at which a patient with SCA2 or SCA3 would reach an onset V-NAA value. Results showed the following: the NAA/Cr ratio decreased with increasing age in patients with SCA but not in control subjects; the SARA score increased progressively with age and duration of illness; V-NAA showed a better correlation with SARA score than R-NAA in patients with SCA2 or SCA3; the ratio of age to V-NAA correlated well with CAG repeat number; the retrospectively predicted age of onset for SCA2 and SCA3 was consistent with patient-reported age of onset; R-NAA showed a better correlation with SARA score than V-NAA in patients with SCA6; V-NAA and R-NAA correlated with clinical severity (SARA score) in patients with SCA. The correlation between CAG repeat number and age could be expressed as a simple linear function, which might explain previous observations claiming that the greater the CAG repeat number, the earlier the onset of illness and the faster the disease progression. These findings support the use of MRS values to predict age of disease onset and to retrospectively evaluate the actual age of disease onset in SCA. PMID:23094053

Crystal Structure of the Golgi-Associated Human Nα-Acetyltransferase 60 Reveals the Molecular Determinants for Substrate-Specific Acetylation.

PubMed

Støve, Svein Isungset; Magin, Robert S; Foyn, Håvard; Haug, Bengt Erik; Marmorstein, Ronen; Arnesen, Thomas

2016-07-06

N-Terminal acetylation is a common and important protein modification catalyzed by N-terminal acetyltransferases (NATs). Six human NATs (NatA-NatF) contain one catalytic subunit each, Naa10 to Naa60, respectively. In contrast to the ribosome-associated NatA to NatE, NatF/Naa60 specifically associates with Golgi membranes and acetylates transmembrane proteins. To gain insight into the molecular basis for the function of Naa60, we developed an Naa60 bisubstrate CoA-peptide conjugate inhibitor, determined its X-ray structure when bound to CoA and inhibitor, and carried out biochemical experiments. We show that Naa60 adapts an overall fold similar to that of the catalytic subunits of ribosome-associated NATs, but with the addition of two novel elongated loops that play important roles in substrate-specific binding. One of these loops mediates a dimer to monomer transition upon substrate-specific binding. Naa60 employs a catalytic mechanism most similar to Naa50. Collectively, these data reveal the molecular basis for Naa60-specific acetyltransferase activity with implications for its Golgi-specific functions. Copyright © 2016 Elsevier Ltd. All rights reserved.

N-acetylaspartate (NAA) correlates inversely with cannabis use in a frontal language processing region of neocortex in MDMA (Ecstasy) polydrug users: a 3 T magnetic resonance spectroscopy study.

PubMed

Cowan, Ronald L; Joers, James M; Dietrich, Mary S

2009-03-01

Impaired verbal memory is common in MDMA (Ecstasy) polydrug users. The contributions of Ecstasy or polydrug exposure to reduced verbal memory are unclear, as is the neural basis for this cognitive deficit. Ecstasy users have reduced gray matter in brain regions mediating verbal memory (BA 18, 21 and 45). N-acetylaspartate (NAA) as a neuronal marker and myoinositol (mI) as a glial marker are inconsistently affected in Ecstasy users. We used 3 T MRS in 17 recreational drug users to test the hypothesis that Ecstasy polydrug use would be associated with altered NAA or mI in BA 18, 21 and 45. No effects were seen for mI. Metabolite ratios for NAA (mean+/-SD) were: BA 18-NAA/Cr (2.030+/-0.188); BA 21-NAA/Cr (1.861+/-0.325); BA 45-NAA/Cr (1.925+/-0.329). Lifetime cannabis use was significantly associated with BA 45 NAA/Cr (r=-0.687, p=0.014) but not with NAA in BA 18 or 21. In contrast, there were no statistically significant associations for lifetime use of Ecstasy, alcohol, or cocaine with NAA. These findings suggest that cannabis use may contribute to altered neuronal integrity in Ecstasy polydrug users in a brain region associated with verbal memory processing.

N-acetylaspartate (NAA) correlates inversely with cannabis use in a frontal language processing region of neocortex in MDMA (Ecstasy) Polydrug Users: a 3 Tesla Magnetic Resonance Spectroscopy Study

PubMed Central

Cowan, Ronald L; Joers, James M; Dietrich, Mary S

2015-01-01

Impaired verbal memory is common in MDMA (Ecstasy) polydrug users. The contributions of Ecstasy or polydrug exposure to reduced verbal memory are unclear, as is the neural basis for this cognitive deficit. Ecstasy users have reduced gray matter in brain regions mediating verbal memory (BA 18, 21 and 45). N-acetylaspartate (NAA) as a neuronal marker and myoinositol (mI) as a glial marker are inconsistently affected in Ecstasy users. We used 3 Tesla MRS in 17 recreational drug users to test the hypothesis that Ecstasy polydrug use would be associated with altered NAA or mI in BA 18, 21 and 45. No effects were seen for mI. Metabolite ratios for NAA (mean ± SD) were: BA 18--NAA/Cr (2.030 ± 0.188); BA 21--NAA/Cr (1.861 ± 0.325); BA 45--NAA/Cr (1.925 ± 0.329). Lifetime cannabis use was significantly associated with BA 45 NAA/Cr (r = −0.687, p = 0.014) but not with NAA in BA 18 or 21. In contrast, there were no statistically significant associations for lifetime use of Ecstasy, alcohol, or cocaine with NAA. These findings suggest that cannabis use may contribute to altered neuronal integrity in Ecstasy polydrug users in a brain region associated with verbal memory processing. PMID:19032963

Clinic-based testing for rectal and pharyngeal Neisseria gonorrhoeae and Chlamydia trachomatis infections by community-based organizations--five cities, United States, 2007.

PubMed

2009-07-10

CDC recommends screening of at-risk men who have sex with men (MSM) at least annually for urethral and rectal gonorrhea and chlamydia, and for pharyngeal gonorrhea. Although the standard method for diagnosis is culture, nucleic acid amplification (NAA) testing is generally more sensitive and favored by most experts. NAA tests have not been cleared by the Food and Drug Administration (FDA) for the diagnosis of extragenital chlamydia or gonorrhea and may not be marketed for that purpose. However, under U.S. law, laboratories may offer NAA testing for diagnosis of extragenital chlamydia or gonorrhea after internal validation of the method by a verification study. To determine sexually transmitted disease (STD) testing practices among community-based organizations serving MSM, CDC and the San Francisco Department of Public Health gathered data on rectal and pharyngeal gonorrhea and chlamydia testing at screening sites managed by six gay-focused community-based organizations in five U.S. cities during 2007. This report summarizes the results of the study, which found that three organizations collected samples for NAA testing and three for culture. In total, approximately 30,000 tests were performed; 5.4% of rectal gonorrhea, 8.9% of rectal chlamydia, 5.3% of pharyngeal gonorrhea, and 1.6% of pharyngeal chlamydia tests were positive. These results demonstrate that gay-focused community-based organizations can detect large numbers of gonorrhea and chlamydia cases and might reach MSM not being tested elsewhere. Public health officials could consider providing support to certain community-based organizations to facilitate testing and treatment of gonorrhea and chlamydia.

N-Acetylaspartate Reduction in the Medial Prefrontal Cortex Following 8 weeks of Risperidone Treatment in First-Episode Drug-Naïve Schizophrenia Patients

PubMed Central

Zong, Xiaofen; Hu, Maolin; Li, Zongchang; Cao, Hongbao; He, Ying; Liao, Yanhui; Zhou, Jun; Sang, Deen; Zhao, Hongzeng; Tang, Jinsong; Lv, Luxian; Chen, Xiaogang

2015-01-01

It is unclear whether N-acetylaspartate (NAA) depletions documented in schizophrenia patients might be due to the disease progression or medications. Here we investigated longitudinal NAA changes in drug-naïve first-episode patients (FEP) who are relatively free from chronicity. Forty-two drug-naïve FEP and 38 controls were enrolled in this study to explore the effect of 8-week risperidone monotherapy on NAA. All spectra were obtained from the medial prefrontal cortex (MPFC) on a 3.0 T MRI and analyzed with LCModel. At baseline, patients presented no significant differences in NAA (P = 0.084) or NAA/Cr + Pcr (P = 0.500) compared to controls; NAA levels were negatively correlated with PANSS total scores (P = 0.001) and WCST-PE (P = 0.041). After treatment, patients demonstrated significant reductions of NAA (P < 0.001) and NAA/Cr + Pcr (P < 0.001), and significant improvement in PANSS-P (P < 0.001) and PANSS-G (P < 0.001) symptoms. We detected no significant correlations between NAA alterations and PANSS-P (P = 0.679) or PANSS-G (P = 0.668) symptom changes; nor did NAA/Cr + Pcr changes with alterations in PANSS-P (P = 0.677) and PANSS-G (P = 0.616). This is the first evidence that short-term risperidone treatment induces an acute reduction of MPFC NAA during the early phase of schizophrenia, which may be a previously unavailable biomarker to indicate risperidone with a similar pharmacological mechanism, although the functional significance is still unclear. PMID:25778460

Decrease of NAA with aging outside the seizure focus in mesial temporal lobe epilepsy--a proton-MRS study at 3 Tesla.

PubMed

Riederer, Franz; Bittsanský, Michal; Lehner-Baumgartner, Eva; Baumgartner, Christoph; Mlynárik, Vladimír; Gruber, Stephan; Moser, Ewald; Kaya, Marihan; Serles, Wolfgang

2007-11-07

There is evidence that chronic pharmacoresistant temporal lobe epilepsy (TLE) is a progressive disorder accompanied by mental deterioration. We investigated effects of aging on cerebral N-acetyl-aspartate (NAA) concentrations in the temporal lobe of 12 patients with pharmacoresistant mesial TLE (mTLE) and 22 healthy controls by means of proton-magnetic resonance spectroscopy ((1)H-MRS) at 3 T. Furthermore, we calculated correlations between NAA concentrations and measures of verbal and figural memory in patients. In mTLE patients but not in healthy controls the concentration of NAA in the lateral temporal lobe was negatively correlated with age. In patients with mTLE NAA in left lateral temporal voxels correlated with verbal memory. NAA in medial temporal voxels did not correlate with age or neuropsychological measures. Significant decrease of NAA with age in the lateral temporal lobe of patients with mTLE provides evidence for progressive neuronal dysfunction with aging. NAA is a marker of neuronal integrity since it correlates with verbal memory.

Reproducibility over a 1-month period of 1H-MR spectroscopic imaging NAA/Cr ratios in clinically stable multiple sclerosis patients.

PubMed

Mostert, J P; Blaauw, Y; Koch, M W; Kuiper, A J; Hoogduin, J M; De Keyser, J

2008-08-01

N-acetylaspartate/creatine (NAA/Cr) ratios, assessed with proton magnetic resonance spectroscopy, are increasingly used as a surrogate marker for axonal dysfunction and degeneration in multiple sclerosis (MS). The purpose of this study was to test short-time reproducibility of NAA/Cr ratios in patients with clinically stable MS. In 35 MS patients we analysed NAA/Cr ratios obtained with (1)H-MR spectroscopic imaging at the centrum semiovale either with lateral ventricles partially included (group 1; n=15) or more cranially with no ventricles included (group 2; n=20). To test short-term reproducibility of the NAA/Cr measurements, patients were scanned twice 4 weeks apart. We determined mean NAA/Cr and Cho/Cr ratios of 12 grey matter and 24 white matter voxels. Mean NAA/Cr ratios of both the white and grey matter did not change after 4 weeks. Overall 4-week reproducibility of the NAA/Cr ratio, expressed as coefficient of variation, was 4.8% for grey matter and 3.5% for white matter. Reproducibility of cranial scanning of the ventricles was slightly better than with cerebrospinal fluid included. Our study shows good short-term reproducibility of NAA/Cr ratio measurements in the centrum semiovale, which supports the reliability of this technique for longitudinal studies.

Reduced concentrations of N-acetylaspartate (NAA) and the NAA-creatine ratio in the basal ganglia in bipolar disorder: a study using 3-Tesla proton magnetic resonance spectroscopy.

PubMed

Frye, Mark A; Thomas, M Albert; Yue, Kenneth; Binesh, Nader; Davanzo, Pablo; Ventura, Joseph; O'Neill, Joseph; Guze, Barry; Curran, John G; Mintz, Jim

2007-04-15

The N-acetylaspartate (NAA) peak is prominent in the proton magnetic resonance spectrum and is thought to reflect neuron loss or dysfunction. This study was conducted to explore NAA biochemistry and its clinical correlates in mania. Subjects comprised 16 manic patients and 17 controls who underwent a structured diagnostic interview and (1)H magnetic resonance spectroscopy (MRS) acquisition. STEAM (1)H MRS (TR/TE/TM=2000/20/8 ms) was acquired at 3 Tesla from 2 x 2 x 2 cm(3) voxels in anterior cingulate (AC), right basal ganglia (BG), and left occipital-parietal white matter (OP). Absolute metabolite concentrations and ratios to creatine were calculated using the LC Model. The mean absolute concentrations of NAA and NAA-creatine ratio in the BG were significantly lower in manic subjects than in controls. There was a significant inverse correlation between NAA in the BG and the number of prior hospitalizations for mania. These data suggest BG pathology in mania and that NAA decrements may mark prior manic episode burden. Limitations of this study include small sample size and lack of tissue segmentation. Further study is encouraged to clarify state vs. trait aspects of NAA in bipolar disorder.

hNaa10p contributes to tumorigenesis by facilitating DNMT1-mediated tumor suppressor gene silencing

PubMed Central

Lee, Chung-Fan; Ou, Derick S.-C.; Lee, Sung-Bau; Chang, Liang-Hao; Lin, Ruo-Kai; Li, Ying-Shiuan; Upadhyay, Anup K.; Cheng, Xiaodong; Wang, Yi-Ching; Hsu, Han-Shui; Hsiao, Michael; Wu, Cheng-Wen; Juan, Li-Jung

2010-01-01

Hypermethylation-mediated tumor suppressor gene silencing plays a crucial role in tumorigenesis. Understanding its underlying mechanism is essential for cancer treatment. Previous studies on human N-α-acetyltransferase 10, NatA catalytic subunit (hNaa10p; also known as human arrest-defective 1 [hARD1]), have generated conflicting results with regard to its role in tumorigenesis. Here we provide multiple lines of evidence indicating that it is oncogenic. We have shown that hNaa10p overexpression correlated with poor survival of human lung cancer patients. In vitro, enforced expression of hNaa10p was sufficient to cause cellular transformation, and siRNA-mediated depletion of hNaa10p impaired cancer cell proliferation in colony assays and xenograft studies. The oncogenic potential of hNaa10p depended on its interaction with DNA methyltransferase 1 (DNMT1). Mechanistically, hNaa10p positively regulated DNMT1 enzymatic activity by facilitating its binding to DNA in vitro and its recruitment to promoters of tumor suppressor genes, such as E-cadherin, in vivo. Consistent with this, interaction between hNaa10p and DNMT1 was required for E-cadherin silencing through promoter CpG methylation, and E-cadherin repression contributed to the oncogenic effects of hNaa10p. Together, our data not only establish hNaa10p as an oncoprotein, but also reveal that it contributes to oncogenesis through modulation of DNMT1 function. PMID:20592467

Increasing N-acetylaspartate in the Brain during Postnatal Myelination Does Not Cause the CNS Pathologies of Canavan Disease

PubMed Central

Appu, Abhilash P.; Moffett, John R.; Arun, Peethambaran; Moran, Sean; Nambiar, Vikram; Krishnan, Jishnu K. S.; Puthillathu, Narayanan; Namboodiri, Aryan M. A.

2017-01-01

Canavan disease is caused by mutations in the gene encoding aspartoacylase (ASPA), a deacetylase that catabolizes N-acetylaspartate (NAA). The precise involvement of elevated NAA in the pathogenesis of Canavan disease is an ongoing debate. In the present study, we tested the effects of elevated NAA in the brain during postnatal development. Mice were administered high doses of the hydrophobic methyl ester of NAA (M-NAA) twice daily starting on day 7 after birth. This treatment increased NAA levels in the brain to those observed in the brains of Nur7 mice, an established model of Canavan disease. We evaluated various serological parameters, oxidative stress, inflammatory and neurodegeneration markers and the results showed that there were no pathological alterations in any measure with increased brain NAA levels. We examined oxidative stress markers, malondialdehyde content (indicator of lipid peroxidation), expression of NADPH oxidase and nuclear translocation of the stress-responsive transcription factor nuclear factor (erythroid-derived 2)-like 2 (NRF-2) in brain. We also examined additional pathological markers by immunohistochemistry and the expression of activated caspase-3 and interleukin-6 by Western blot. None of the markers were increased in the brains of M-NAA treated mice, and no vacuoles were observed in any brain region. These results show that ASPA expression prevents the pathologies associated with excessive NAA concentrations in the brain during postnatal myelination. We hypothesize that the pathogenesis of Canavan disease involves not only disrupted NAA metabolism, but also excessive NAA related signaling processes in oligodendrocytes that have not been fully determined and we discuss some of the potential mechanisms. PMID:28626388

Role of diffusion tensor imaging or magnetic resonance spectroscopy in the diagnosis and disability assessment of amyotrophic lateral sclerosis.

PubMed

Liu, Chanchan; Jiang, Rifeng; Yi, Xiyan; Zhu, Wenzhen; Bu, Bitao

2015-01-15

To compare the results of magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI) in amyotrophic lateral sclerosis (ALS) patients. Nineteen ALS patients and thirteen age-matched healthy controls underwent MRS and DTI between October 2013 and July 2014. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), N-acetylaspartate (NAA), choline (Cho), and creatine (Cr) were collected as the quantitative results of the imaging study. The ALS functional rating scale-revised (ALSFRS-R) and disease progression rate were evaluated to assess patients' disability. The imaging study results were compared between ALS patients and healthy controls. The relationship between disability assessment and imaging study results was analyzed. NAA/Cr in the motor cortex and FA in the corticospinal tract (CST) of both sides were significantly lower in patients than controls. There was no significant difference between the two groups in Cho/Cr, tract length, tract volume, ADC or NAA. No relationship was found between ALSFRS-R and FA (r=0.243, p=0.316) in the right CST; NAA (r=0.095, p=0.699) or NAA/Cr (r=0.172, p=0.481) in the left motor cortex; or NAA (r=0.320, p=0.182) or NAA/Cr (r=0.193, p=0.492) in the right motor cortex. There was no relationship between the disease progression rate and FA, NAA, or NAA/Cr on either side. NAA/Cr and FA can help diagnose ALS. Regional brain NAA/Cr and FA values could not assess the ALSFRS-R or disease progression rate. Copyright © 2014 Elsevier B.V. All rights reserved.

Fabrication and Optimization of Bilayered Nanoporous Anodic Alumina Structures as Multi-Point Interferometric Sensing Platform

PubMed Central

Nemati, Mahdieh; Santos, Abel

2018-01-01

Herein, we present an innovative strategy for optimizing hierarchical structures of nanoporous anodic alumina (NAA) to advance their optical sensing performance toward multi-analyte biosensing. This approach is based on the fabrication of multilayered NAA and the formation of differential effective medium of their structure by controlling three fabrication parameters (i.e., anodization steps, anodization time, and pore widening time). The rationale of the proposed concept is that interferometric bilayered NAA (BL-NAA), which features two layers of different pore diameters, can provide distinct reflectometric interference spectroscopy (RIfS) signatures for each layer within the NAA structure and can therefore potentially be used for multi-point biosensing. This paper presents the structural fabrication of layered NAA structures, and the optimization and evaluation of their RIfS optical sensing performance through changes in the effective optical thickness (EOT) using quercetin as a model molecule. The bilayered or funnel-like NAA structures were designed with the aim of characterizing the sensitivity of both layers of quercetin molecules using RIfS and exploring the potential of these photonic structures, featuring different pore diameters, for simultaneous size-exclusion and multi-analyte optical biosensing. The sensing performance of the prepared NAA platforms was examined by real-time screening of binding reactions between human serum albumin (HSA)-modified NAA (i.e., sensing element) and quercetin (i.e., analyte). BL-NAAs display a complex optical interference spectrum, which can be resolved by fast Fourier transform (FFT) to monitor the EOT changes, where three distinctive peaks were revealed corresponding to the top, bottom, and total layer within the BL-NAA structures. The spectral shifts of these three characteristic peaks were used as sensing signals to monitor the binding events in each NAA pore in real-time upon exposure to different concentrations of quercetin. The multi-point sensing performance of BL-NAAs was determined for each pore layer, with an average sensitivity and low limit of detection of 600 nm (mg mL−1)−1 and 0.14 mg mL−1, respectively. BL-NAAs photonic structures have the capability to be used as platforms for multi-point RIfS sensing of biomolecules that can be further extended for simultaneous size-exclusion separation and multi-analyte sensing using these bilayered nanostructures. PMID:29415436

Microcystin-LR-induced phytotoxicity in rice crown root is associated with the cross-talk between auxin and nitric oxide.

PubMed

Chen, Jian; Zhang, Hai-Qiang; Hu, Liang-Bin; Shi, Zhi-Qi

2013-09-01

Irrigation with cyanobacterial-blooming water containing microcystin-LR (MC-LR) poses threat to the growth of agricultural plants. Large amounts of rice (Oryza sativa) field in the middle part of China has been irrigating with cyanobacterial-blooming water. Nevertheless, the mechanism of MC-LR-induced phytotoxicity in the root of monocot rice remains unclear. In the present study, we demonstrate that MC-LR stress significantly inhibits the growth of rice root by impacting the morphogenesis rice crown root. MC-LR treatment results in the decrease in IAA (indole-3-acetic acid) concentration as well as the expression of CRL1 and WOX11 in rice roots. The application of NAA (1-naphthylacetic acid), an IAA homologue, is able to attenuate the inhibitory effect of MC-LR on rice root development. MC-LR treatment significantly inhibits OsNia1-dependent NO generation in rice roots. The application of NO donor SNP (sodium nitroprusside) is able to partially reverse the inhibitory effects of MC-LR on the growth of rice root and the expression of CRL1 and WOX11 by enhancing endogenous NO level in rice roots. The application of NO scavenger cPTIO [2-(4-carboxy-2-phenyl)-4,4,5,5-tetramethylinidazoline-1-oxyl-3-oxide] eliminates the effects of SNP. Treatment with NAA stimulates the generation of endogenous NO in MC-LR-treated rice roots. Treatment with NO scavenger cPTIO abolishes the ameliorated effect of NAA on MC-LR-induced growth inhibition of rice root. Treatment with SNP enhanced IAA concentration in MC-LR-treated rice roots. Altogether, our data suggest that NO acts both downstream and upstream of auxin in regulating rice root morphogenesis under MC-LR stress. Copyright © 2013 Elsevier Ltd. All rights reserved.

Multiple shoot induction from axillary bud cultures of the medicinal orchid, Dendrobium longicornu

PubMed Central

Dohling, Stadwelson; Kumaria, Suman; Tandon, Pramod

2012-01-01

Background and aims Dendrobium longicornu, commonly known as the ‘Long-horned Dendrobium’, is an endangered and medicinally important epiphytic orchid. Over-exploitation and habitat destruction seriously threaten this orchid in Northeast India. Our objective was to develop an efficient protocol for the mass propagation of D. longicornu using axillary bud segments. Methodology and principal results Axillary buds cultured in Murashige and Skoog semi-solid medium supplemented with α-naphthalene acetic acid (NAA), 2,4-dichlorophenoxy acetic acid (2,4-D) and 6-benzylaminopurine (BAP) readily developed into plantlets. These formed either directly from shoot buds or from intermediary protocorm-like bodies (PLBs). The maximum explant response (86.6 %) was obtained in medium supplemented with NAA at 30 µM, while the maximum number of shoots (4.42) and maximum bud-forming capacity (3.51) were observed in medium containing 15 µM BAP and 5 µM NAA in combination. Protocorm-like bodies were obtained when the medium contained 2,4-D. The maximum number of explants forming PLBs (41.48 %) was obtained in medium containing 15 µM BAP and 15 µM 2,4-D. Well-developed plantlets obtained after 20–25 weeks of culture were acclimatized and eventually transferred to the greenhouse. Over 60 % of these survived to form plants ∼3–4 cm tall after 90 days in glasshouse conditions using a substrate of crushed brick and charcoal, shredded bark and moss. Conclusions The method described can readily be used for the rapid and large-scale regeneration of D. longicornu. Its commercial adoption would reduce the collection of this medicinally important and increasingly rare orchid from the wild. PMID:23136638

Reduced NAA in motor and non-motor brain regions in amyotrophic lateral sclerosis: a cross-sectional and longitudinal study.

PubMed

Rule, R R; Suhy, J; Schuff, N; Gelinas, D F; Miller, R G; Weiner, M W

2004-09-01

After replication of previous findings we aimed to: 1) determine if previously reported (1)H MRSI differences between ALS patients and control subjects are limited to the motor cortex; and 2) determine the longitudinal metabolic changes corresponding to varying levels of diagnostic certainty. Twenty-one patients with possible/suspected ALS, 24 patients with probable/definite ALS and 17 control subjects underwent multislice (1)H MRSI co-registered with tissue-segmented MRI to obtain concentrations of the brain metabolites N-acetylaspartate (NAA), creatine, and choline in the left and right motor cortex and in gray matter and white matter of non-motor regions in the brain. In the more affected hemisphere, reductions in the ratios, NAA/Cho and NAA/Cre+Cho were observed both within (12.6% and 9.5% respectively) and outside (9.2% and 7.3% respectively) the motor cortex in probable/definite ALS. However, these reductions were significantly greater within the motor cortex (P<0.05 for NAA/Cho and P<0.005 for NAA/Cre+Cho). Longitudinal changes in NAA were observed at three months within the motor cortex of both possible/suspected ALS patients (P<0.005) and at nine months outside the motor cortex of probable/definite patients (P<0.005). However, there was no clear pattern of progressive change over time. NAA ratios are reduced in the motor cortex and outside the motor cortex in ALS, suggesting widespread neuronal injury. Longitudinal changes of NAA are not reliable, suggesting that NAA may not be a useful surrogate marker for treatment trials.

N-Acetylaspartate reductions in brain injury: impact on post-injury neuroenergetics, lipid synthesis, and protein acetylation

PubMed Central

Moffett, John R.; Arun, Peethambaran; Ariyannur, Prasanth S.; Namboodiri, Aryan M. A.

2013-01-01

N-Acetylaspartate (NAA) is employed as a non-invasive marker for neuronal health using proton magnetic resonance spectroscopy (MRS). This utility is afforded by the fact that NAA is one of the most concentrated brain metabolites and that it produces the largest peak in MRS scans of the healthy human brain. NAA levels in the brain are reduced proportionately to the degree of tissue damage after traumatic brain injury (TBI) and the reductions parallel the reductions in ATP levels. Because NAA is the most concentrated acetylated metabolite in the brain, we have hypothesized that NAA acts in part as an extensive reservoir of acetate for acetyl coenzyme A synthesis. Therefore, the loss of NAA after TBI impairs acetyl coenzyme A dependent functions including energy derivation, lipid synthesis, and protein acetylation reactions in distinct ways in different cell populations. The enzymes involved in synthesizing and metabolizing NAA are predominantly expressed in neurons and oligodendrocytes, respectively, and therefore some proportion of NAA must be transferred between cell types before the acetate can be liberated, converted to acetyl coenzyme A and utilized. Studies have indicated that glucose metabolism in neurons is reduced, but that acetate metabolism in astrocytes is increased following TBI, possibly reflecting an increased role for non-glucose energy sources in response to injury. NAA can provide additional acetate for intercellular metabolite trafficking to maintain acetyl CoA levels after injury. Here we explore changes in NAA, acetate, and acetyl coenzyme A metabolism in response to brain injury. PMID:24421768

Reduced N-acetylaspartate levels in the frontal cortex of 3,4-methylenedioxymethamphetamine (Ecstasy) users: preliminary results.

PubMed

Reneman, Liesbeth; Majoie, Charles B L M; Flick, Herman; den Heeten, Gerard J

2002-02-01

The perceived safety of the recreational drug methylenedioxymethamphetamine (MDMA), or Ecstasy, conflicts with animal evidence indicating that MDMA damages cortical serotonin (5-HT) neurons at doses similar to those used by humans. Few data are available about the effects of MDMA on the human brain. This study was designed to evaluate MDMA-related alterations in metabolite ratios with single-voxel proton ((1)H) MR spectroscopy. Fifteen male MDMA users (mean lifetime exposure, 723 tablets; mean time since last tablet, 12.0 weeks) and 12 age-matched control subjects underwent single-voxel (1)H MR spectroscopy. N-Acetylaspartate (NAA)/creatine (Cr), NAA/Choline (Cho), and myoinositol (MI)/Cr ratios were measured in midfrontal gray matter, midoccipital gray matter, and right parietal white matter. Data were analyzed with linear model-based multivariate analysis of variance. NAA/Cr (P =.04) and NAA/Cho (P =.03) ratios, markers associated with neuronal loss or dysfunction, were reduced in the frontal cortex of MDMA users. Neither NAA/Cr (P =.72) nor NAA/Cho (P =.12) ratios were different between both groups in occipital gray matter and parietal white matter (P =.18). Extent of previous MDMA use and frontal cortical NAA/Cr (rho = -.50, P =.012) or NAA/Cho (rho = -.550, P <.01) ratios were significantly associated. Reduced NAA/Cr and NAA/Cho ratios at (1)H MR spectroscopy provide evidence for neuronal abnormality in the frontal cortex of MDMA users; these are correlated with the degree of MDMA exposure. These data suggest that MDMA may be a neurotoxin in humans, as it is in animals.

Generation and multiplication of plantlets from callus derived from Haplopappus gracilus (Nutt.) Gray and their karyotype analysis

NASA Technical Reports Server (NTRS)

Kann, R. P.; O'Connor, S. A.; Levine, H. G.; Krikorian, A. D.

1991-01-01

Unopened flower heads of Haplopappus gracilis (2n = 4) provided primary explants for callus production and subsequent induction of organized growth. Callus was initiated from small (3-5 mm in length) floral buds with benzylaminopurine (BAP) (44.4 micromoles; 10 mg/l) and naphthalene acetic acid (NAA) (0.54 micromole; 0.1 mg/l). Lowering the BAP level to 4.44 micromoles (1 mg/l) but maintaining the NAA level, gave rise to organized but highly compressed shoot growing points from an otherwise undifferentiated callus mass. Shoots selected from such cultures were maintainable and could be proliferated by growing 1-1.5-cm stem tip cuttings on Murashige and Skoog basal medium (solidified with agar) containing 0.444 micromole (0.1 mg/l) BAP and 0.054 micromole (0.01 mg/l) NAA. The stem tip multiplication rates obtainable by these means permit reliable strategies for shoot multiplication or production of rooted plantlets. Prolonged subculture and maintenance of shoots on growth regulator-free medium leads to in vitro flowering and greatly reduces rooting capacity. Karyotype analysis of chromosomes from root tip cells at metaphase and chromosome measurements show that karyologically uniform plantlets (based on chromosome number and morphology) can be obtained.

Application of Box-Behnken design for modeling of lead adsorption onto unmodified and NaCl-modified zeolite NaA obtained from biosilica.

PubMed

Terzioğlu, Pinar; Yücel, Sevil; Öztürk, Mehmet

2017-01-01

The main objective of the present study was to optimize lead adsorption onto zeolite NaA. For this purpose, to synthesize zeolite NaA under hydrothermal conditions, local wheat husk was precleaned with chemical treatment using hydrochloric acid solution. The unmodified (ZU) and NaCl-modified (ZN) zeolites were characterized by Brunauer-Emmett-Teller, scanning electron microscopy coupled with energy dispersive spectroscopy and X-ray diffraction. The optimization of adsorption process was examined using Box-Behnken Experimental Design in response surface methodology by Design Expert Version 7.0.0 (Stat-Ease, USA). The effects of initial lead (II) concentration, temperature, and time were selected as independent variables. Lack of fit test indicates that the quadratic regression model was significant with the high coefficients of determination values for both adsorbents. Optimum process conditions for lead (II) adsorption onto ZU and ZN were found to be 64.40°C and 64.80°C, respectively, and 90.80 min, and 350 mg L -1 initial lead(II) concentration for both adsorbents. Under these conditions, maximum adsorption capacities of ZU and ZN for lead (II) were 293.38 mg g -1 and 321.85 mg g -1 , respectively.

NAA-Induced Direct Organogenesis from Female Immature Inflorescence Explants of Date Palm.

PubMed

Khierallah, Hussam S M; Bader, Saleh M; Al-Khafaji, Makki A

2017-01-01

Micropropagation has great potential for the multiplication of female and male date palms of commercially grown cultivars by using inflorescences. This approach is simple, convenient, and much faster than the conventional method of using shoot-tip explants. We describe here a stepwise micropropagation procedure using inflorescence explants of Iraqi date palm cultivar Maktoom. Cultured explants were derived from 0.5-cm-long spike segments excised from 8 to 10-cm-long spathes. About 70% formed adventitious buds on Murashige and Skoog (MS) medium supplemented with 2 mg/L naphthalene acetic acid (NAA), 4 mg/L benzylaminopurine (BAP), and 40 g/L sucrose and maintained in the dark for 16 weeks before transferring to normal light conditions. The best multiplication rate was achieved with 3 mg/L 2ip and 2 mg/L; for shoot elongation, the best medium is MS containing 0.5 mg/L BAP, 0.5 mg/L 2ip, and 1 mg/L GA 3 . Well-developed shoots were cultured for rooting in half MS medium amended with 1 mg/L NAA and 45 g/L sucrose. Plantlets with well-developed roots were successfully hardened in the greenhouse. Inflorescence explants proved to be a promising alternative explant source for micropropagation of date palm cultivars.

Methamphetamine-induced neuronal protein NAT8L is the NAA biosynthetic enzyme: implications for specialized acetyl coenzyme A metabolism in the CNS.

PubMed

Ariyannur, Prasanth S; Moffett, John R; Manickam, Pachiappan; Pattabiraman, Nagarajan; Arun, Peethambaran; Nitta, Atsumi; Nabeshima, Toshitaka; Madhavarao, Chikkathur N; Namboodiri, Aryan M A

2010-06-04

N-acetylaspartate (NAA) is a concentrated, neuron-specific brain metabolite routinely used as a magnetic resonance spectroscopy marker for brain injury and disease. Despite decades of research, the functional roles of NAA remain unclear. Biochemical investigations over several decades have associated NAA with myelin lipid synthesis and energy metabolism. However, studies have been hampered by an inability to identify the gene for the NAA biosynthetic enzyme aspartate N-acetyltransferase (Asp-NAT). A very recent report has identified Nat8l as the gene encoding Asp-NAT and confirmed that the only child diagnosed with a lack of NAA on brain magnetic resonance spectrograms has a 19-bp deletion in this gene. Based on in vitro Nat8l expression studies the researchers concluded that many previous biochemical investigations have been technically flawed and that NAA may not be associated with brain energy or lipid metabolism. In studies done concurrently in our laboratory we have demonstrated via cloning, expression, specificity for acetylation of aspartate, responsiveness to methamphetamine treatment, molecular modeling and comparative immunolocalization that NAT8L is the NAA biosynthetic enzyme Asp-NAT. We conclude that NAA is a major storage and transport form of acetyl coenzyme A specific to the nervous system, thus linking it to both lipid synthesis and energy metabolism. Published by Elsevier B.V.

Hippocampal metabolic dysfunction in juvenile myoclonic epilepsy: 3D multivoxel spectroscopy study.

PubMed

Ristić, Aleksandar J; Ostojić, Jelena; Kozić, Duško; Vojvodić, Nikola M; Popović, Ljubica M; Janković, Slavko; Baščarević, Vladimir; Sokić, Dragoslav V

2011-06-15

To investigate the metabolic differences in hippocampi of patients with juvenile myoclonic epilepsy (JME) and healthy controls using magnetic resonance spectroscopy (MRS). A 3D multivoxel SE 135 MRS study on 1.5 T scanner of both hippocampi was performed in 17 patients with JME and normal brain MRI and in 19 age and sex matched controls. Three dominant signals were measured: Choline (Cho), Creatine (tCr) and N-Acetylaspartate (NAA) and expressed as ratios of Cho:tCr, NAA:tCr, NAA:Cho and NAA:(Cho+tCr). Metabolite ratios in head, body and tail of each hippocampus in the JME group of patients were compared with ratios from corresponding structures in the control group. We found a significant difference in metabolite ratios of both hippocampi between the JME and the control groups. We detected significant differences of Cho:tCr in the head, NAA:tCr in the head, body and tail, NAA:Cho and NAA:(Cho+tCr) in the body and tail of the left hippocampus, and NAA:Cho and NAA:(Cho+tCr) in the body and tail of the right hippocampus. Although not previously recognized as a part of the epileptogenic network, our results suggest that the hippocampus, well recognized as a key player in focal epilepsies, may have a certain role in the pathogenesis of JME. Copyright © 2010. Published by Elsevier B.V.

Structure and function of human Naa60 (NatF), a Golgi-localized bi-functional acetyltransferase

DOE PAGES

Chen, Ji-Yun; Liu, Liang; Cao, Chun-Ling; ...

2016-08-23

N-terminal acetylation (Nt-acetylation), carried out by N-terminal acetyltransferases (NATs), is a conserved and primary modification of nascent peptide chains. Naa60 (also named NatF) is a recently identified NAT found only in multicellular eukaryotes. This protein was shown to locate on the Golgi apparatus and mainly catalyze the Nt-acetylation of transmembrane proteins, and it also harbors lysine Nε -acetyltransferase (KAT) activity to catalyze the acetylation of lysine ε-amine. Here, we report the crystal structures of human Naa60 (hNaa60) in complex with Acetyl-Coenzyme A (Ac-CoA) or Coenzyme A (CoA). The hNaa60 protein contains an amphipathic helix following its GNAT domain that maymore » contribute to Golgi localization of hNaa60, and the β7-β8 hairpin adopted different conformations in the hNaa60(1-242) and hNaa60(1-199) crystal structures. Remarkably, we found that the side-chain of Phe 34 can influence the position of the coenzyme, indicating a new regulatory mechanism involving enzyme, co-factor and substrates interactions. Moreover, structural comparison and biochemical studies indicated that Tyr 97 and His 138 are key residues for catalytic reaction and that a non-conserved β3-β4 long loop participates in the regulation of hNaa60 activity.« less

Effects of IBA and NAA treatments on rooting Douglas-fir stem cuttings.

Treesearch

D.L. Copes

2000-01-01

The effectiveness of six IBA and four NAA concentrations, four combinations of IBA and NAA concentrations, and control were tested for their ability to enhance rooting frequency (%) of Douglas-fir cuttings. Two IBA and one NAA treatments were also compared to the control for quality of root system. Between 1984 and 1998, six independent studies were conducted in mist...

The Proceedings, Directory and Handbook of the National Association of Academies of Science 1983-84.

ERIC Educational Resources Information Center

Majumdar, Shyamal K., Ed.

Provided in this document are the proceedings of the 1983 annual meeting of the National Association of Academies of Sciences (NAAS), the NAAS handbook, and the NAAS directory. The proceedings also include papers presented at a symposium on the crisis in science and mathematics education, various NAAS reports, and abstracts of American Junior…

The relationship between Cho/NAA and glioma metabolism: implementation for margin delineation of cerebral gliomas.

PubMed

Guo, Jun; Yao, Chengjun; Chen, Hong; Zhuang, Dongxiao; Tang, Weijun; Ren, Guang; Wang, Yin; Wu, Jinsong; Huang, Fengping; Zhou, Liangfu

2012-08-01

The marginal delineation of gliomas cannot be defined by conventional imaging due to their infiltrative growth pattern. Here we investigate the relationship between changes in glioma metabolism by proton magnetic resonance spectroscopic imaging ((1)H-MRSI) and histopathological findings in order to determine an optimal threshold value of choline/N-acetyl-aspartate (Cho/NAA) that can be used to define the extent of glioma spread. Eighteen patients with different grades of glioma were examined using (1)H-MRSI. Needle biopsies were performed under the guidance of neuronavigation prior to craniotomy. Intraoperative magnetic resonance imaging (MRI) was performed to evaluate the accuracy of sampling. Haematoxylin and eosin, and immunohistochemical staining with IDH1, MIB-1, p53, CD34 and glial fibrillary acidic protein (GFAP) antibodies were performed on all samples. Logistic regression analysis was used to determine the relationship between Cho/NAA and MIB-1, p53, CD34, and the degree of tumour infiltration. The clinical threshold ratio distinguishing tumour tissue in high-grade (grades III and IV) glioma (HGG) and low-grade (grade II) glioma (LGG) was calculated. In HGG, higher Cho/NAA ratios were associated with a greater probability of higher MIB-1 counts, stronger CD34 expression, and tumour infiltration. Ratio threshold values of 0.5, 1.0, 1.5 and 2.0 appeared to predict the specimens containing the tumour with respective probabilities of 0.38, 0.60, 0.79, 0.90 in HGG and 0.16, 0.39, 0.67, 0.87 in LGG. HGG and LGG exhibit different spectroscopic patterns. Using (1)H-MRSI to guide the extent of resection has the potential to improve the clinical outcome of glioma surgery.

In Vitro Propagation of Muña-Muña (Clinopodium odorum (Griseb.) Harley)

PubMed Central

Diaz, María Soledad; Palacio, Lorena; Figueroa, Ana Cristina; Goleniowski, Marta Ester

2012-01-01

A micropropagation protocol was developed which may assist in the safeguarding and augmentation of dwindling natural populations of Clinopodium odorum (Griseb.) Harley, a critically and endangered medicinal plant. Factors affecting culture initiation bud sprouting and growth, rooting, and acclimatization were studied, using nodal segments of in vitro germinated seedling as primary explants on six media supplemented with different concentrations and combinations of 6-benzylaminopurine (BAP) (0.5–1.5 and 2-Naphthalene acetic acid (NAA) (0.5–1.5). Best results for culture initiation with sustainable multiplication rates (100%) were obtained on WP medium without any growth regulator. WP with the addition of 0.5 : 1 or 0.5 : 1.5) of BAP and NAA promoted a higher elongation; however, the optimum number of nodes were obtained in plantlets grown on 1/2 MS with the addition of 1 : 1.5 of BAP and NAA. Culture of sectioned individual nodes transferred to the media with different rates of BAP and NAA 1/2 MS-9 (1.5 : 1.5), SH-8 (1.5 : 1.0), and 1/2 B5-4 (1.0 : 0.5) media resulted in no proliferated shoots. The in vitro plants were successfully acclimatized garden soil and sand (2 : 1) in the greenhouse, with over 90% survival rate. The in vitro-grown plants could be transferred to ex vitro conditions and the efficacy in supporting ex vitro growth was assessed, with a view to develope longer-term strategies for the transfer and reintroduction into natural habitats. PMID:23119167

Association of urinary citrate excretion, pH, and net gastrointestinal alkali absorption with diet, diuretic use, and blood glucose concentration.

PubMed

Perinpam, Majuran; Ware, Erin B; Smith, Jennifer A; Turner, Stephen T; Kardia, Sharon L R; Lieske, John C

2017-10-01

Urinary citrate (Ucit) protects against urinary stone formation. Acid base status and diet influence Ucit. However, the effect of demographics, diet, and glucose metabolism on Ucit excretion, urinary pH (U-pH) and net gastrointestinal alkali absorption (NAA) are not known. Twenty-four hour urine samples, blood glucose, creatinine, and cystatin C were obtained from non-Hispanic white sibships in Rochester, MN ( n  = 446; 64.5 ± 9 years; 58% female). Diet was assessed by a food frequency questionnaire. The impact of blood glucose, demographics and dietary elements on Ucit excretion, U-pH, and NAA were evaluated in bivariate and multivariable models and interaction models that included age, sex, and weight. NAA significantly associated with Ucit and U-pH In multivariate models Ucit increased with age, weight, eGFR C ys , and blood glucose, but decreased with loop diuretic and thiazide use. U-pH decreased with serum creatinine, blood glucose, and dietary protein but increased with dietary potassium. NAA was higher in males and increased with age, weight, eGFR C ys and dietary potassium. Significant interactions were observed for Ucit excretion with age and blood glucose, weight and eGFR C ys, and sex and thiazide use. Blood glucose had a significant and independent effect on U-pH and also Ucit. This study provides the first evidence that blood glucose could influence urinary stone risk independent of urinary pH, potentially providing new insight into the association of obesity and urinary stone disease. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

The neuronal metabolite NAA regulates histone H3 methylation in oligodendrocytes and myelin lipid composition

PubMed Central

Singhal, N. K.; Huang, H.; Li, S.; Clements, R.; Gadd, J.; Daniels, A.; Kooijman, E. E.; Bannerman, P.; Burns, T.; Guo, F.; Pleasure, D.; Freeman, E.; Shriver, L.

2017-01-01

The neuronal mitochondrial metabolite N-acetylaspartate (NAA) is decreased in the multiple sclerosis (MS) brain. NAA is synthesized in neurons by the enzyme N-acetyltransferase-8-like (NAT8L) and broken down in oligodendrocytes by aspartoacylase (ASPA) into acetate and aspartate. We have hypothesized that NAA links the metabolism of axons with oligodendrocytes to support myelination. To test this hypothesis, we performed lipidomic analyses using liquid chromatography–tandem mass spectrometry (LC–MS/MS) and high-performance thin-layer chromatography (HPTLC) to identify changes in myelin lipid composition in postmortem MS brains and in NAT8L knockout (NAT8L−/−) mice which do not synthesize NAA. We found reduced levels of sphingomyelin in MS normal appearing white matter that mirrored decreased levels of NAA. We also discovered decreases in the amounts of sphingomyelin and sulfatide lipids in the brains of NAT8L−/− mice compared to controls. Metabolomic analysis of primary cultures of oligodendrocytes treated with NAA revealed increased levels of α-ketoglutarate, which has been reported to regulate histone demethylase activity. Consistent with this, NAA treatment resulted in alterations in the levels of histone H3 methylation, including H3K4me3, H3K9me2, and H3K9me3. The H3K4me3 histone mark regulates cellular energetics, metabolism, and growth, while H3K9me3 has been linked to alterations in transcriptional repression in developing oligodendrocytes. We also noted the NAA treatment was associated with increases in the expression of genes involved in sulfatide and sphingomyelin synthesis in cultured oligodendrocytes. This is the first report demonstrating that neuronal-derived NAA can signal to the oligodendrocyte nucleus. These data suggest that neuronal-derived NAA signals through epigenetic mechanisms in oligodendrocytes to support or maintain myelination. PMID:27709268

The neuronal metabolite NAA regulates histone H3 methylation in oligodendrocytes and myelin lipid composition.

PubMed

Singhal, N K; Huang, H; Li, S; Clements, R; Gadd, J; Daniels, A; Kooijman, E E; Bannerman, P; Burns, T; Guo, F; Pleasure, D; Freeman, E; Shriver, L; McDonough, J

2017-01-01

The neuronal mitochondrial metabolite N-acetylaspartate (NAA) is decreased in the multiple sclerosis (MS) brain. NAA is synthesized in neurons by the enzyme N-acetyltransferase-8-like (NAT8L) and broken down in oligodendrocytes by aspartoacylase (ASPA) into acetate and aspartate. We have hypothesized that NAA links the metabolism of axons with oligodendrocytes to support myelination. To test this hypothesis, we performed lipidomic analyses using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and high-performance thin-layer chromatography (HPTLC) to identify changes in myelin lipid composition in postmortem MS brains and in NAT8L knockout (NAT8L -/- ) mice which do not synthesize NAA. We found reduced levels of sphingomyelin in MS normal appearing white matter that mirrored decreased levels of NAA. We also discovered decreases in the amounts of sphingomyelin and sulfatide lipids in the brains of NAT8L -/- mice compared to controls. Metabolomic analysis of primary cultures of oligodendrocytes treated with NAA revealed increased levels of α-ketoglutarate, which has been reported to regulate histone demethylase activity. Consistent with this, NAA treatment resulted in alterations in the levels of histone H3 methylation, including H3K4me3, H3K9me2, and H3K9me3. The H3K4me3 histone mark regulates cellular energetics, metabolism, and growth, while H3K9me3 has been linked to alterations in transcriptional repression in developing oligodendrocytes. We also noted the NAA treatment was associated with increases in the expression of genes involved in sulfatide and sphingomyelin synthesis in cultured oligodendrocytes. This is the first report demonstrating that neuronal-derived NAA can signal to the oligodendrocyte nucleus. These data suggest that neuronal-derived NAA signals through epigenetic mechanisms in oligodendrocytes to support or maintain myelination.

Age-modulated association between prefrontal NAA and the BDNF gene.

PubMed

Salehi, Basira; Preuss, Nora; van der Veen, Jan Willem; Shen, Jun; Neumeister, Alexander; Drevets, Wayne C; Hodgkinson, Colin; Goldman, David; Wendland, Jens R; Singleton, Andrew; Gibbs, Jesse R; Cookson, Mark R; Hasler, Gregor

2013-07-01

Brain-derived neurotrophic factor (BDNF) has been implicated in the pathophysiology of psychiatric and neurological disorders and in the mechanisms of antidepressant pharmacotherapy. Psychiatric and neurological conditions have also been associated with reduced brain levels of N-acetyl-aspartate (NAA), which has been used as a putative marker of neural integrity. However, few studies have explored the relationship between BDNF polymorphisms and NAA levels directly. Here, we present data from a single-voxel proton magnetic resonance spectroscopy study of 64 individuals and explore the relationship between BDNF polymorphisms and prefrontal NAA level. Our results indicate an association between a single nucleotide polymorphism (SNP) within BDNF, known as rs1519480, and reduced NAA level (p = 0.023). NAA levels were further predicted by age and Asian ancestry. There was a significant rs1519480 × age interaction on NAA level (p = 0.031). Specifically, the effect of rs1519480 on NAA level became significant at age ⩾34.17 yr. NAA level decreased with advancing age for genotype TT (p = 0.001) but not for genotype CT (p = 0.82) or CC (p = 0.34). Additional in silico analysis of 142 post-mortem brain samples revealed an association between the same SNP and reduced BDNF mRNA expression in the prefrontal cortex. The rs1519480 SNP influences BDNF mRNA expression and has an impact on prefrontal NAA level over time. This genetic mechanism may contribute to inter-individual variation in cognitive performance seen during normal ageing, as well as contributing to the risk for developing psychiatric and neurological conditions.

Molecular identification and functional characterization of the first Nα-acetyltransferase in plastids by global acetylome profiling.

PubMed

Dinh, Trinh V; Bienvenut, Willy V; Linster, Eric; Feldman-Salit, Anna; Jung, Vincent A; Meinnel, Thierry; Hell, Rüdiger; Giglione, Carmela; Wirtz, Markus

2015-07-01

Protein N(α) -terminal acetylation represents one of the most abundant protein modifications of higher eukaryotes. In humans, six N(α) -acetyltransferases (Nats) are responsible for the acetylation of approximately 80% of the cytosolic proteins. N-terminal protein acetylation has not been evidenced in organelles of metazoans, but in higher plants is a widespread modification not only in the cytosol but also in the chloroplast. In this study, we identify and characterize the first organellar-localized Nat in eukaryotes. A primary sequence-based search in Arabidopsis thaliana revealed seven putatively plastid-localized Nats of which AT2G39000 (AtNAA70) showed the highest conservation of the acetyl-CoA binding pocket. The chloroplastic localization of AtNAA70 was demonstrated by transient expression of AtNAA70:YFP in Arabidopsis mesophyll protoplasts. Homology modeling uncovered a significant conservation of tertiary structural elements between human HsNAA50 and AtNAA70. The in vivo acetylation activity of AtNAA70 was demonstrated on a number of distinct protein N(α) -termini with a newly established global acetylome profiling test after expression of AtNAA70 in E. coli. AtNAA70 predominately acetylated proteins starting with M, A, S and T, providing an explanation for most protein N-termini acetylation events found in chloroplasts. Like HsNAA50, AtNAA70 displays N(ε) -acetyltransferase activity on three internal lysine residues. All MS data have been deposited in the ProteomeXchange with identifier PXD001947 (http://proteomecentral.proteomexchange.org/dataset/PXD001947). © 2015 The Authors. PROTEOMICS Published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

An Open-Label Exploratory Study with Memantine: Correlation between Proton Magnetic Resonance Spectroscopy and Cognition in Patients with Mild to Moderate Alzheimer's Disease

PubMed Central

Gordon, Marc L.; Kingsley, Peter B.; Goldberg, Terry E.; Koppel, Jeremy; Christen, Erica; Keehlisen, Lynda; Kohn, Nina; Davies, Peter

2012-01-01

Aim To characterize progression of Alzheimer's disease (AD) using proton magnetic resonance spectroscopy (1H MRS). Methods Eleven subjects with mild to moderate AD underwent neurocognitive testing and single-voxel 1H MRS from the precuneus and posterior cingulate region at baseline, after 24 weeks of monotherapy with a cholinesterase inhibitor, and after another 24 weeks of combination therapy with open-label memantine and a cholinesterase inhibitor. Baseline metabolites [N-acetylaspartate (NAA), myo-inositol (mI), choline (Cho), and creatine (Cr)] and their ratios in AD subjects were compared with those of an age-matched control group of 28 cognitively normal subjects. Results AD subjects had significantly higher mI/Cr and lower NAA, NAA/Cr, NAA/Cho, and NAA/mI. Baseline Alzheimer's Disease Cooperative Study Activities of Daily Living (ADCS-ADL) scores significantly correlated with NAA/Cr, mI/Cr, and NAA/mI. There was an increase in mI and a decrease in NAA/mI, but no significant change in other metabolites or ratios, or neurocognitive measures, when memantine was added to a cholinesterase inhibitor. Conclusion Metabolite ratios significantly differed between AD and control subjects. Baseline metabolite ratios correlated with function (ADCS-ADL). There was an increase in mI and a decrease in NAA/mI, but no changes in other metabolites, ratios, or cognitive measures, when memantine was added to a cholinesterase inhibitor. PMID:22962555

Widespread extrahippocampal NAA/(Cr+Cho) abnormalities in TLE with and without mesial temporal sclerosis.

PubMed

Mueller, Susanne G; Ebel, Andreas; Barakos, Jerome; Scanlon, Cathy; Cheong, Ian; Finlay, Daniel; Garcia, Paul; Weiner, Michael W; Laxer, Kenneth D

2011-04-01

MR spectroscopy has demonstrated extrahippocampal NAA/(Cr+Cho) reductions in medial temporal lobe epilepsy with (TLE-MTS) and without (TLE-no) mesial temporal sclerosis. Because of the limited brain coverage of those previous studies, it was, however, not possible to assess differences in the distribution and extent of these abnormalities between TLE-MTS and TLE-no. This study used a 3D whole brain echoplanar spectroscopic imaging (EPSI) sequence to address the following questions: (1) Do TLE-MTS and TLE-no differ regarding severity and distribution of extrahippocampal NAA/(Cr+Cho) reductions? (2) Do extrahippocampal NAA/(Cr+Cho) reductions provide additional information for focus lateralization? Forty-three subjects (12 TLE-MTS, 13 TLE-no, 18 controls) were studied with 3D EPSI. Statistical parametric mapping (SPM2) was used to identify regions of significantly decreased NAA/(Cr+Cho) in TLE groups and in individual patients. TLE-MTS and TLE-no had widespread extrahippocampal NAA/(Cr+Cho) reductions. NAA/(Cr+Cho) reductions had a bilateral fronto-temporal distribution in TLE-MTS and a more diffuse, less well defined distribution in TLE-no. Extrahippocampal NAA/(Cr+Cho) decreases in the single subject analysis showed a large inter-individual variability and did not provide additional focus lateralizing information. Extrahippocampal NAA/(Cr+Cho) reductions in TLE-MTS and TLE-no are neither focal nor homogeneous. This reduces their value for focus lateralization and suggests a heterogeneous etiology of extrahippocampal spectroscopic metabolic abnormalities in TLE.

Depletion of histone N-terminal-acetyltransferase Naa40 induces p53-independent apoptosis in colorectal cancer cells via the mitochondrial pathway.

PubMed

Pavlou, Demetria; Kirmizis, Antonis

2016-03-01

Protein N-terminal acetylation is an abundant post-translational modification in eukaryotes implicated in various fundamental cellular and biochemical processes. This modification is catalysed by evolutionarily conserved N-terminal acetyltransferases (NATs) whose deregulation has been linked to cancer development and thus, are emerging as useful diagnostic and therapeutic targets. Naa40 is a highly selective NAT that acetylates the amino-termini of histones H4 and H2A and acts as a sensor of cell growth in yeast. In the present study, we examine the role of Naa40 in cancer cell survival. We demonstrate that depletion of Naa40 in HCT116 and HT-29 colorectal cancer cells decreases cell survival by enhancing apoptosis, whereas Naa40 reduction in non-cancerous mouse embryonic fibroblasts has no effect on cell viability. Specifically, Naa40 knockdown in colon cancer cells activates the mitochondrial caspase-9-mediated apoptotic cascade. Consistent with this, we show that caspase-9 activation is required for the induced apoptosis because treatment of cells with an irreversible caspase-9 inhibitor impedes apoptosis when Naa40 is depleted. Furthermore, the effect of Naa40-depletion on cell-death is mediated through a p53-independent mechanism since p53-null HCT116 cells still undergo apoptosis upon reduction of the acetyltransferase. Altogether, these findings reveal an anti-apoptotic role for Naa40 and exhibit its potential as a therapeutic target in colorectal cancers.

Micropropagation of Helleborus through axillary budding.

PubMed

Beruto, Margherita; Viglione, Serena; Bisignano, Alessandro

2013-01-01

Helleborus genus, belonging to the Ranunculaceae family, has 20 species of herbaceous perennial flowering plants. The commercial exploitation of this plant is dependent on the selection and propagation of appropriate lines. High propagation rate could be accomplished by using a suitable tissue culture method enabling the rapid introduction of valuable selections in the market. However, in vitro cultivation of Helleborus is still very difficult. Thereby the development of reliable in vitro propagation procedures is crucial for future production systems. Axillary buds cultured on agar-solidified Murashige and Skoog medium supplemented with 1 mg/L benzyladenine, 0.1 mg/L β-naphthoxyacetic acid, and 2 mg/L isopentenyl adenine develop shoots after 16 weeks of culture under 16 h light regime, 50-60 μmol/s/m(2), and 19 ± 1°C. The multiplication rate ranges from 1.4 to 2.1. However, the genotype and the number of subcultures affect the efficiency of the micropropagation process. The rooting of shoots is about 80% in solidified MS medium containing 1 mg/L 1-naphthaleneacetic acid and 3 mg/L indole-3-butyric acid. The described protocol provides information which can contribute to the commercial production of Helleborus plants.

Diffusion properties of NAA in human corpus callosum as studied with diffusion tensor spectroscopy.

PubMed

Upadhyay, Jaymin; Hallock, Kevin; Erb, Kelley; Kim, Dae-Shik; Ronen, Itamar

2007-11-01

In diffusion tensor imaging (DTI) the anisotropic movement of water is exploited to characterize microstructure. One confounding issue of DTI is the presence of intra- and extracellular components contributing to the measured diffusivity. This causes an ambiguity in determining the underlying cause of diffusion properties, particularly the fractional anisotropy (FA). In this study an intracellular constituent, N-acetyl aspartate (NAA), was used to probe intracellular diffusion, while water molecules were used to probe the combined intra- and extracellular diffusion. NAA and water diffusion measurements were made in anterior and medial corpus callosum (CC) regions, which are referred to as R1 and R2, respectively. FA(NAA) was found to be greater than FA(Water) in both CC regions, thus indicating a higher degree of anisotropy within the intracellular space in comparison to the combined intra- and extracellular spaces. A decreasing trend in the FA of NAA and water was observed between R1 and R2, while the radial diffusivity (RD) for both molecules increased. The increase in RD(NAA) is particularly significant, thus explaining the more significant decrease in FA(NAA) between the two regions. It is suggested that diffusion tensor spectroscopy of NAA can potentially be used to further characterize microscopic anatomic organization in white matter. Copyright 2007 Wiley-Liss, Inc.

The Molecular Mechanisms Affecting N-Acetylaspartate Homeostasis Following Experimental Graded Traumatic Brain Injury

PubMed Central

Di Pietro, Valentina; Amorini, Angela Maria; Tavazzi, Barbara; Vagnozzi, Roberto; Logan, Ann; Lazzarino, Giacomo; Signoretti, Stefano; Lazzarino, Giuseppe; Belli, Antonio

2014-01-01

To characterize the molecular mechanisms of N-acetylaspartate (NAA) metabolism following traumatic brain injury (TBI), we measured the NAA, adenosine triphosphate (ATP) and adenosine diphosphate (ADP) concentrations and calculated the ATP/ADP ratio at different times from impact, concomitantly evaluating the gene and protein expressions controlling NAA homeostasis (the NAA synthesizing and degrading enzymes N-acetyltransferase 8-like and aspartoacylase, respectively) in rats receiving either mild or severe TBI. The reversible changes in NAA induced by mild TBI were due to a combination of transient mitochondrial malfunctioning with energy crisis (decrease in ATP and in the ATP/ADP ratio) and modulation in the gene and protein levels of N-acetyltransferase 8-like and increase of aspartoacylase levels. The irreversible decrease in NAA following severe TBI, was instead characterized by profound mitochondrial malfunctioning (constant 65% decrease of the ATP/ADP indicating permanent impairment of the mitochondrial phosphorylating capacity), dramatic repression of the N-acetyltransferase 8-like gene and concomitant remarkable increase in the aspartoacylase gene and protein levels. The mechanisms underlying changes in NAA homeostasis following graded TBI might be of note for possible new therapeutic approaches and will help in understanding the effects of repeat concussions occurring during particular periods of the complex NAA recovery process, coincident with the so called window of brain vulnerability. PMID:24515258

Realisation and optical engineering of linear variable bandpass filters in nanoporous anodic alumina photonic crystals.

PubMed

Sukarno; Law, Cheryl Suwen; Santos, Abel

2017-06-08

We present the first realisation of linear variable bandpass filters in nanoporous anodic alumina (NAA-LVBPFs) photonic crystal structures. NAA gradient-index filters (NAA-GIFs) are produced by sinusoidal pulse anodisation and used as photonic crystal platforms to generate NAA-LVBPFs. The anodisation period of NAA-GIFs is modified from 650 to 850 s to systematically tune the characteristic photonic stopband of these photonic crystals across the UV-visible-NIR spectrum. Then, the nanoporous structure of NAA-GIFs is gradually widened along the surface under controlled conditions by wet chemical etching using a dip coating approach aiming to create NAA-LVBPFs with finely engineered optical properties. We demonstrate that the characteristic photonic stopband and the iridescent interferometric colour displayed by these photonic crystals can be tuned with precision across the surface of NAA-LVBPFs by adjusting the fabrication and etching conditions. Here, we envisage for the first time the combination of the anodisation period and etching conditions as a cost-competitive, facile, and versatile nanofabrication approach that enables the generation of a broad range of unique LVBPFs covering the spectral regions. These photonic crystal structures open new opportunities for multiple applications, including adaptive optics, hyperspectral imaging, fluorescence diagnostics, spectroscopy, and sensing.

SU-E-I-34: Intermittent Low- and High-Dose Ethanol Exposure Alters Neurochemical Responses in Adult Rat Brain: An Ex Vivo 1H NMR Spectroscopy at 11.7 T

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Do-Wan; Kim, Sang-Young; Song, Kyu-Ho

Purpose: The first goal of this study was to determine the influence of the dose-dependent effects of intermittent ethanol intoxication on cerebral neurochemical responses among sham controls and low- and high-dose-ethanol-exposed rats with ex vivo high-resolution spectra. The second goal of this study was to determine the correlations between the metabolite-metabolite levels (pairs-of-metabolite levels) from all of the individual data from the frontal cortex of the intermittent ethanol-intoxicated rats. Methods: Eight-week-old male Wistar rats were divided into 3 groups. Twenty rats in the LDE (n = 10) and the HDE (n = 10) groups received ethanol doses of 1.5 g/kgmore » and 2.5 g/kg, respectively, through oral gavage every 8-h for 4 days. At the end of the 4-day intermittent ethanol exposure, one-dimensional ex vivo 500-MHz proton nuclear magnetic resonance spectra were acquired from 30 samples of the frontal cortex region (from the 3 groups). Results: Normalized total-N-acetylaspartate (tNAA: NAA + NAAG [N-acetylaspartyl-glutamate]), gamma-aminobutyric acid (GABA), and glutathione (GSH) levels were significantly lower in the frontal cortex of the HDE-exposed rats than that of the LDE-exposed rats. Moreover, compared to the CNTL group, the LDE rats exhibited significantly higher normalized GABA levels. The 6 pairs of normalized metabolite levels were positively (+) or negatively (−) correlated in the rat frontal cortex as follows: tNAA and GABA (+), tNAA and Aspartate (Asp) (−), myo-Inositol (mIns) and Asp (−), mIns and Alanine (+), mIns and Taurine (+), and mIns and tNAA (−). Conclusion: Our results suggested that repeated intermittent ethanol intoxication might result in neuronal degeneration and dysfunction, changes in the rate of GABA synthesis, and oxidative stress in the rat frontal cortex. Our ex vivo 1H high-resolution-magic angle spinning nuclear magnetic resonance spectroscopy results suggested some novel metabolic markers for the dose-dependent influence of repeated intermittent ethanol intoxication in the frontal cortex.« less

Diet quality influences isotopic discrimination among amino acids in an aquatic vertebrate

PubMed Central

Chikaraishi, Yoshito; Steffan, Shawn A; Takano, Yoshinori; Ohkouchi, Naohiko

2015-01-01

Stable nitrogen isotopic composition of amino acids (δ15NAA) has recently been employed as a powerful tool in ecological food web studies, particularly for estimating the trophic position (TP) of animal species in food webs. However, the validity of these estimates depends on the consistency of the trophic discrimination factor (TDF; - Δδ15NAA at each shift of trophic level) among a suite of amino acids within the tissues of consumer species. In this study, we determined the TDF values of amino acids in tadpoles (the Japanese toad, Bufo japonicus) reared exclusively on one of three diets that differed in nutritional quality. The diets were commercial fish-food pellets (plant and animal biomass), bloodworms (animal biomass), and boiled white rice (plant carbohydrate), representing a balanced, protein-rich, and protein-poor diet, respectively. The TDF values of two “source amino acids” (Src-AAs), methionine and phenylalanine, were close to zero (0.3–0.5‰) among the three diets, typifying the values reported in the literature (∼0.5‰ and ∼0.4‰, respectively). However, TDF values of “trophic amino acids” (Tr-AAs) including alanine, valine, leucine, isoleucine, and glutamic acid varied by diet: for example, the glutamic acid TDF was similar to the standard value (∼8.0‰) when tadpoles were fed either the commercial pellets (8.0‰) or bloodworms (7.9‰), but when they were fed boiled rice, the TDF was significantly reduced (0.6‰). These results suggest that a profound lack of dietary protein may alter the TDF values of glutamic acid (and other Tr-AAs and glycine) within consumer species, but not the two Src-AAs (i.e., methionine and phenylalanine). Knowledge of how a nutritionally poor diet can influence the TDF of Tr- and Src-AAs will allow amino acid isotopic analyses to better estimate TP among free-roaming animals. PMID:26045955

N-doped carbon nanotubes-reinforced hollow fiber solid-phase microextraction coupled with high performance liquid chromatography for the determination of phytohormones in tomatoes.

PubMed

Han, Xiao-Fei; Chen, Juan; Shi, Yan-Ping

2018-08-01

A N-doped carbon nanotubes-reinforced hollow fiber solid-phase microextraction (N-doped CNTs-HF-SPME) method was developed for determination of two naphthalene-derived phytohormones, 1-naphthalene acetic acid (NAA) and 2-naphthoxyacetic acid (2-NOA), at trace levels in tomatoes. N-doped CNTs were dispersed in ultrapure water with the assistance of surfactant, and then immobilized into the pores of hollow fiber by capillary forces and sonification. The resultant N-doped CNTs-HF was wetted with 1-octanol, subsequently immersed into the tomato samples to extract the target analytes under a magnetic stirring, and then desorbed with methanol by sonication prior to chromatographic analysis. Compared with CNTs, the surface hydrophilicity of N-doped CNTs was improved owing to the doping of nitrogen atoms, and a uniform dispersion was formed, thus greatly simplifying the preparation process and reducing waste of materials. In addition, N-doped CNTs-HF exhibits a more effective extraction performance for NAA and 2-NOA on account of the introduction of Lewis-basic nitrogen. It is worth to mention that owing to the clean-up function of HF, there are not any complicated sample pretreatment procedures prior to the microextraction. To achieve the highest extraction efficiency, important microextraction parameters including the length and the concentration level of N-doped CNTs in surfactant solution, extraction time, desorption conditions such as the type and volume of solvents, pH value, stirring rate and volume of the donor phase were thoroughly investigated and optimized. Under the optimal conditions, the method showed 165- and 123-fold enrichment factors of NAA and 2-NOA, good inter-fiber repeatability and batch-to-batch reproducibility, good linearity with correlation coefficients higher than 0.9990, low limits of detection and quantification (at ng g -1 levels), and satisfactory recoveries in the range of 83.10-108.32% at three spiked levels. The proposed method taking advantages of both excellent adsorption performance of N-doped CNTs and the clean-up function of HF, was a simple, green, efficient and cost-effective enrichment procedure for the determination of trace NAA and 2-NOA in tomatoes. Copyright © 2018 Elsevier B.V. All rights reserved.

A simple and efficient protocol for the mass propagation of Cymbidium mastersii: an ornamental orchid of Northeast India

PubMed Central

Mohanty, Padmaja; Paul, Sumi; Das, Meera C.; Kumaria, Suman; Tandon, Pramod

2012-01-01

Background and aims Cymbidium mastersii is an epiphytic orchid distributed mainly in Northeast India. Owing to its high commercial value in the floricultural industry, natural populations are under threat from over-exploitation. Mass propagation provides an alternative means of satisfying the demand. Unfortunately, conventional propagation is slow and difficult, suggesting in vitro methods for mass multiplication may be more appropriate. The objective of this study was to develop an efficient protocol. Methodology and principal results Four nutrient media were evaluated for seed germination and early protocorm development: Murashige and Skoog (MS), half-strength MS, Knudson ‘C’ (KC), and Vacin and Went (VW). In addition, the effects of plant growth regulators 6-benzylaminopurine (BAP), kinetin (KN), α-naphthalene acetic acid (NAA) and indole-3-butyric acid (IBA) were studied alone and in combination. The maximum percentage seed germination (93.58 ± 0.56) was obtained in MS basal medium after 8–9 weeks of culture. Secondary protocorms (protocorm-like bodies) were developed from primary protocorms on MS medium fortified with different concentrations and combinations of cytokinins (BAP and KN) and auxins (NAA and IBA). The highest numbers of secondary protocorms (20.55 ± 0.62)/primary protocorms were obtained in MS medium supplemented with 5.0 µM BAP and 2.5 µM NAA. The most effective auxin source promoting root production (7.46 ± 0.09 per shoot) was 10.0 µM IBA. The plants were acclimatized effectively (survival percentage 88 %) in a greenhouse using a rooting medium of crushed sterile brick and charcoal (1 : 1 v/v) and vermicompost (leaf litter + cow dung, 1 : 1 v/v). Conclusions An efficient protocol was established for in vitro propagation of C. mastersii using seed as the starting material. The percentage seed germination varied with the composition of the nutrient media and was highest in full-strength MS basal medium. The number of secondary protocorms that developed from primary protocorms was increased by the addition of 5.0 µM BAP and 2.5 µM NAA. In vitro raised plantlets acclimatized in a greenhouse were closely similar to the mother plants in morphology. PMID:22997547

Application of plant growth regulators, a simple technique for improving the establishment success of plant cuttings in coastal dune restoration

NASA Astrophysics Data System (ADS)

Balestri, Elena; Vallerini, Flavia; Castelli, Alberto; Lardicci, Claudio

2012-03-01

Exogenous application of plant growth regulators (PGRs) may be an effective technique for increasing the rooting ability and the growth of vegetative fragments (cuttings) of plants used in dune restoration programs. Various concentrations (0, 50 and 100 mg l-1) of two auxins, alpha-naphtaleneacetic acid (NAA) and indole-3-butyric acid (IBA), and two cytokinins, 6-furfurylaminopurine (Kinetin) and 6-benzylaminopurine (BAP), were applied separately to cuttings of two widely used species for restoration, Ammophila arenaria and Sporobuls virginicus. Root development and production of new buds in cuttings were examined under laboratory conditions one month after application. Cuttings were also examined one year after transplanting into a sandy substratum under natural conditions, to test for possible long term effects of PGRs on plant establishment success and growth. The response of the two study species to PGRs differed substantially. In A. arenaria the auxin NAA at 100 mg l-1 reduced the time for root initiation and increased the rooting capacity of cuttings, while the cytokinin Kinetin at 50 mg l-1 facilitated root growth. No auxin had effect on rooting or growth of S. virginicus cuttings, but treatment with 100 mg l-1 Kinetin resulted in higher rooting success than the control. One year after planting, the cuttings of A. arenaria treated with 100 mg l-1 NAA showed a higher establishment success (90% vs. 55%) and produced more culms and longer roots than the control; those treated with cytokinins did not differ in the establishment success from the control, but had longer roots, more culms and rhizomes. On the other hand, the cuttings of S. virginicus treated with 100 mg l-1 Kinetin showed a higher establishment success (75% vs. 35%) and had more culms than the control. Therefore, in restoration activities that involved A. arenaria, a pre-treatment of cuttings with NAA would be beneficial, as it allows the production of a higher number of well-developed plants with high survival potential and greater area cover. In contrast, a pre-treatment of cuttings of S. virginicus with Kinetin would achieve more acceptable plant survival rates. This easy and low cost-effective technique may be extended to other dune plant species and applied on a large scale to improve the chance of dune restoration success.

Rational engineering of nanoporous anodic alumina optical bandpass filters

NASA Astrophysics Data System (ADS)

Santos, Abel; Pereira, Taj; Law, Cheryl Suwen; Losic, Dusan

2016-08-01

Herein, we present a rationally designed advanced nanofabrication approach aiming at producing a new type of optical bandpass filters based on nanoporous anodic alumina photonic crystals. The photonic stop band of nanoporous anodic alumina (NAA) is engineered in depth by means of a pseudo-stepwise pulse anodisation (PSPA) approach consisting of pseudo-stepwise asymmetric current density pulses. This nanofabrication method makes it possible to tune the transmission bands of NAA at specific wavelengths and bandwidths, which can be broadly modified across the UV-visible-NIR spectrum through the anodisation period (i.e. time between consecutive pulses). First, we establish the effect of the anodisation period as a means of tuning the position and width of the transmission bands of NAA across the UV-visible-NIR spectrum. To this end, a set of nanoporous anodic alumina bandpass filters (NAA-BPFs) are produced with different anodisation periods, ranging from 500 to 1200 s, and their optical properties (i.e. characteristic transmission bands and interferometric colours) are systematically assessed. Then, we demonstrate that the rational combination of stacked NAA-BPFs consisting of layers of NAA produced with different PSPA periods can be readily used to create a set of unique and highly selective optical bandpass filters with characteristic transmission bands, the position, width and number of which can be precisely engineered by this rational anodisation approach. Finally, as a proof-of-concept, we demonstrate that the superposition of stacked NAA-BPFs produced with slight modifications of the anodisation period enables the fabrication of NAA-BPFs with unprecedented broad transmission bands across the UV-visible-NIR spectrum. The results obtained from our study constitute the first comprehensive rationale towards advanced NAA-BPFs with fully controllable photonic properties. These photonic crystal structures could become a promising alternative to traditional optical bandpass filters based on glass and plastic.Herein, we present a rationally designed advanced nanofabrication approach aiming at producing a new type of optical bandpass filters based on nanoporous anodic alumina photonic crystals. The photonic stop band of nanoporous anodic alumina (NAA) is engineered in depth by means of a pseudo-stepwise pulse anodisation (PSPA) approach consisting of pseudo-stepwise asymmetric current density pulses. This nanofabrication method makes it possible to tune the transmission bands of NAA at specific wavelengths and bandwidths, which can be broadly modified across the UV-visible-NIR spectrum through the anodisation period (i.e. time between consecutive pulses). First, we establish the effect of the anodisation period as a means of tuning the position and width of the transmission bands of NAA across the UV-visible-NIR spectrum. To this end, a set of nanoporous anodic alumina bandpass filters (NAA-BPFs) are produced with different anodisation periods, ranging from 500 to 1200 s, and their optical properties (i.e. characteristic transmission bands and interferometric colours) are systematically assessed. Then, we demonstrate that the rational combination of stacked NAA-BPFs consisting of layers of NAA produced with different PSPA periods can be readily used to create a set of unique and highly selective optical bandpass filters with characteristic transmission bands, the position, width and number of which can be precisely engineered by this rational anodisation approach. Finally, as a proof-of-concept, we demonstrate that the superposition of stacked NAA-BPFs produced with slight modifications of the anodisation period enables the fabrication of NAA-BPFs with unprecedented broad transmission bands across the UV-visible-NIR spectrum. The results obtained from our study constitute the first comprehensive rationale towards advanced NAA-BPFs with fully controllable photonic properties. These photonic crystal structures could become a promising alternative to traditional optical bandpass filters based on glass and plastic. Electronic supplementary information (ESI) available: An example demonstrating the effect of pore widening on the position and width of the transmission band of a NAA-BPF and a comprehensive table summarising the position and FWHM of the different bands of the NAA-BPFs produced in this study. See DOI: 10.1039/c6nr03490j

N-acetylaspartate (NAA) induces neuronal differentiation of SH-SY5Y neuroblastoma cell line and sensitizes it to chemotherapeutic agents

PubMed Central

Mazzoccoli, Carmela; Ruggieri, Vitalba; Tataranni, Tiziana; Agriesti, Francesca; Laurenzana, Ilaria; Fratello, Angelo; Capitanio, Nazzareno; Piccoli, Claudia

2016-01-01

Neuroblastoma is the most commonly extra-cranial solid tumor of childhood frequently diagnosed. The nervous system-specific metabolite N-acetylaspartate (NAA) is synthesized from aspartate and acetyl-CoA in neurons, it is among the most abundant metabolites present in the central nervous system (CNS) and appears to be involved in many CNS disorders. The functional significance of the high NAA concentration in the brain remains uncertain, but it confers to NAA a unique clinical significance exploited in magnetic resonance spectroscopy. In the current study, we show that treatment of SH-SY5Y neuroblastoma-derived cell line with sub-cytotoxic physiological concentrations of NAA inhibits cell growth. This effect is partly due to enhanced apoptosis, shown by decrease of the anti-apoptotic factors survivin and Bcl-xL, and partly to arrest of the cell-cycle progression, linked to enhanced expression of the cyclin-inhibitors p53, p21Cip1/Waf1 and p27Kip1. Moreover, NAA-treated SH-SY5Y cells exhibited morphological changes accompanied with increase of the neurogenic markers TH and MAP2 and down-regulation of the pluripotency markers OCT4 and CXCR4/CD184. Finally, NAA-pre-treated SH-SY5Y cells resulted more sensitive to the cytotoxic effect of the chemotherapeutic drugs Cisplatin and 5-fluorouracil. To our knowledge, this is the first study demonstrating the neuronal differentiating effects of NAA in neuroblastoma cells. NAA may be a potential preconditioning or adjuvant compound in chemotherapeutic treatment. PMID:27036033

N-Acetylaspartylglutamate (NAAG) and N-Acetylaspartate (NAA) in Patients With Schizophrenia

PubMed Central

Jessen, Frank; Fingerhut, Natascha; Sprinkart, Alois M.; Kühn, Kai-Uwe; Petrovsky, Nadine; Maier, Wolfgang; Schild, Hans-H; Block, Wolfgang; Wagner, Michael; Träber, Frank

2013-01-01

Background : Imbalance of glutamatergic neurotransmission has been proposed as a key mechanism underlying symptoms of schizophrenia. The neuropetide N-acetylaspartylglutamate (NAAG) modulates glutamate release. NAAG provides a component of the proton magnetic resonance spectrum (1H-MRS) in humans. The signal of NAAG, however, largely overlaps with its precursor and degrading product N-acetylaspartate (NAA) that by itself does not act in glutamatergic neurotransmission. Methods: We quantified NAAG and NAA separately from the 1H-MRS signal in 20 patients with schizophrenia and 20 healthy comparison subjects on a 3.0 Tesla MR scanner. The 1H-MRS voxels were positioned in the anterior cingulate cortex (ACC) and in the left frontal lobe. Psychopathological symptoms and cognitive performance were assessed. Results: In the ACC, the ratio NAAG/NAA was increased (P = .041) and NAAG was increased at a trend level (P = .066) in patients, while NAA was reduced (P = .030). NAA correlated with attention performance in patients (r = .64, P = .005) in the ACC. There was no group difference of NAAG, NAA, or NAAG/NAA in the frontal lobe but an inverse correlation of NAAG with negatives symptoms (Positive and Negative Symptoms Scale [PANSS] negative, r = −.58, P = .018) and with the total symptom score (PANSS total, r = −.50, P = .049). In addition, there was a positive correlation of frontal lobe NAAG (r = .53, P = .035) and NAAG/NAA (r = .54, P = .030) with episodic memory in patients. Conclusions: In this study, we present the first in vivo evidence for altered NAAG concentration in patients with schizophrenia. PMID:21914645

N-acetylaspartate (NAA) induces neuronal differentiation of SH-SY5Y neuroblastoma cell line and sensitizes it to chemotherapeutic agents.

PubMed

Mazzoccoli, Carmela; Ruggieri, Vitalba; Tataranni, Tiziana; Agriesti, Francesca; Laurenzana, Ilaria; Fratello, Angelo; Capitanio, Nazzareno; Piccoli, Claudia

2016-05-03

Neuroblastoma is the most commonly extra-cranial solid tumor of childhood frequently diagnosed. The nervous system-specific metabolite N-acetylaspartate (NAA) is synthesized from aspartate and acetyl-CoA in neurons, it is among the most abundant metabolites present in the central nervous system (CNS) and appears to be involved in many CNS disorders. The functional significance of the high NAA concentration in the brain remains uncertain, but it confers to NAA a unique clinical significance exploited in magnetic resonance spectroscopy. In the current study, we show that treatment of SH-SY5Y neuroblastoma-derived cell line with sub-cytotoxic physiological concentrations of NAA inhibits cell growth. This effect is partly due to enhanced apoptosis, shown by decrease of the anti-apoptotic factors survivin and Bcl-xL, and partly to arrest of the cell-cycle progression, linked to enhanced expression of the cyclin-inhibitors p53, p21Cip1/Waf1 and p27Kip1. Moreover, NAA-treated SH-SY5Y cells exhibited morphological changes accompanied with increase of the neurogenic markers TH and MAP2 and down-regulation of the pluripotency markers OCT4 and CXCR4/CD184. Finally, NAA-pre-treated SH-SY5Y cells resulted more sensitive to the cytotoxic effect of the chemotherapeutic drugs Cisplatin and 5-fluorouracil.To our knowledge, this is the first study demonstrating the neuronal differentiating effects of NAA in neuroblastoma cells. NAA may be a potential preconditioning or adjuvant compound in chemotherapeutic treatment.

N-acetylaspartylglutamate (NAAG) and N-acetylaspartate (NAA) in patients with schizophrenia.

PubMed

Jessen, Frank; Fingerhut, Natascha; Sprinkart, Alois M; Kühn, Kai-Uwe; Petrovsky, Nadine; Maier, Wolfgang; Schild, Hans-H; Block, Wolfgang; Wagner, Michael; Träber, Frank

2013-01-01

BACKGROUND : Imbalance of glutamatergic neurotransmission has been proposed as a key mechanism underlying symptoms of schizophrenia. The neuropetide N-acetylaspartylglutamate (NAAG) modulates glutamate release. NAAG provides a component of the proton magnetic resonance spectrum (1H-MRS) in humans. The signal of NAAG, however, largely overlaps with its precursor and degrading product N-acetylaspartate (NAA) that by itself does not act in glutamatergic neurotransmission. We quantified NAAG and NAA separately from the 1H-MRS signal in 20 patients with schizophrenia and 20 healthy comparison subjects on a 3.0 Tesla MR scanner. The 1H-MRS voxels were positioned in the anterior cingulate cortex (ACC) and in the left frontal lobe. Psychopathological symptoms and cognitive performance were assessed. In the ACC, the ratio NAAG/NAA was increased (P = .041) and NAAG was increased at a trend level (P = .066) in patients, while NAA was reduced (P = .030). NAA correlated with attention performance in patients (r = .64, P = .005) in the ACC. There was no group difference of NAAG, NAA, or NAAG/NAA in the frontal lobe but an inverse correlation of NAAG with negatives symptoms (Positive and Negative Symptoms Scale [PANSS] negative, r = -.58, P = .018) and with the total symptom score (PANSS total, r = -.50, P = .049). In addition, there was a positive correlation of frontal lobe NAAG (r = .53, P = .035) and NAAG/NAA (r = .54, P = .030) with episodic memory in patients. In this study, we present the first in vivo evidence for altered NAAG concentration in patients with schizophrenia.

Analysis of plant hormones by microemulsion electrokinetic capillary chromatography coupled with on-line large volume sample stacking.

PubMed

Chen, Zongbao; Lin, Zian; Zhang, Lin; Cai, Yan; Zhang, Lan

2012-04-07

A novel method of microemulsion electrokinetic capillary chromatography (MEEKC) coupled with on-line large volume sample stacking was developed for the analysis of six plant hormones including indole-3-acetic acid, indole-3-butyric acid, indole-3-propionic acid, 1-naphthaleneacetic acid, abscisic acid and salicylic acid. Baseline separation of six plant hormones was achieved within 10 min by using the microemulsion background electrolyte containing a 97.2% (w/w) 10 mM borate buffer at pH 9.2, 1.0% (w/w) ethyl acetate as oil droplets, 0.6% (w/w) sodium dodecyl sulphate as surfactant and 1.2% (w/w) 1-butanol as cosurfactant. In addition, an on-line concentration method based on a large volume sample stacking technique and multiple wavelength detection was adopted for improving the detection sensitivity in order to determine trace level hormones in a real sample. The optimal method provided about 50-100 fold increase in detection sensitivity compared with a single MEEKC method, and the detection limits (S/N = 3) were between 0.005 and 0.02 μg mL(-1). The proposed method was simple, rapid and sensitive and could be applied to the determination of six plant hormones in spiked water samples, tobacco leaves and 1-naphthylacetic acid in leaf fertilizer. The recoveries ranged from 76.0% to 119.1%, and good reproducibilities were obtained with relative standard deviations (RSDs) less than 6.6%.

Medial Frontal Lobe Neurochemistry in Autism Spectrum Disorder Is Marked by Reduced N-Acetylaspartate and Unchanged Gamma-Aminobutyric Acid and Glutamate + Glutamine Levels

ERIC Educational Resources Information Center

Carvalho Pereira, Andreia; Violante, Inês R.; Mouga, Susana; Oliveira, Guiomar; Castelo-Branco, Miguel

2018-01-01

The nature of neurochemical changes in autism spectrum disorder (ASD) remains controversial. We compared medial prefrontal cortex (mPFC) neurochemistry of twenty high-functioning children and adolescents with ASD without associated comorbidities and fourteen controls. We observed reduced total N-acetylaspartate (tNAA) and total creatine, increased…

Reduced NAA-levels in the NAWM of patients with MS is a feature of progression. A study with quantitative magnetic resonance spectroscopy at 3 Tesla.

PubMed

Aboul-Enein, Fahmy; Krssák, Martin; Höftberger, Romana; Prayer, Daniela; Kristoferitsch, Wolfgang

2010-07-20

Reduced N-acetyl-aspartate (NAA) levels in magnetic resonance spectroscopy (MRS) may visualize axonal damage even in the normal appearing white matter (NAWM). Demyelination and axonal degeneration are a hallmark in multiple sclerosis (MS). To define the extent of axonal degeneration in the NAWM in the remote from focal lesions in patients with relapsing-remitting (RRMS) and secondary progressive MS (SPMS). 37 patients with clinical definite MS (27 with RRMS, 10 with SPMS) and 8 controls were included. We used 2D (1)H-MR-chemical shift imaging (TR = 1500ms, TE = 135ms, nominal resolution 1ccm) operating at 3Tesla to assess the metabolic pattern in the fronto-parietal NAWM. Ratios of NAA to creatine (Cr) and choline (Cho) and absolute concentrations of the metabolites in the NAWM were measured in each voxel matching exclusively white matter on the anatomical T2 weighted MR images. No significant difference of absolute concentrations for NAA, Cr and Cho or metabolite ratios were found between RRMS and controls. In SPMS, the NAA/Cr ratio and absolute concentrations for NAA and Cr were significantly reduced compared to RRMS and to controls. In our study SPMS patients, but not RRMS patients were characterized by low NAA levels. Reduced NAA-levels in the NAWM of patients with MS is a feature of progression.

Auxin as an inducer of asymmetrical division generating the subsidiary cells in stomatal complexes of Zea mays.

PubMed

Livanos, Pantelis; Giannoutsou, Eleni; Apostolakos, Panagiotis; Galatis, Basil

2015-01-01

The data presented in this work revealed that in Zea mays the exogenously added auxins indole-3-acetic acid (IAA) and 1-napthaleneacetic acid (NAA), promoted the establishment of subsidiary cell mother cell (SMC) polarity and the subsequent subsidiary cell formation, while treatment with auxin transport inhibitors 2,3,5-triiodobenzoic acid (TIBA) and 1-napthoxyacetic acid (NOA) specifically blocked SMC polarization and asymmetrical division. Furthermore, in young guard cell mother cells (GMCs) the PIN1 auxin efflux carriers were mainly localized in the transverse GMC faces, while in the advanced GMCs they appeared both in the transverse and the lateral ones adjacent to SMCs. Considering that phosphatidyl-inositol-3-kinase (PI3K) is an active component of auxin signal transduction and that phospholipid signaling contributes in the establishment of polarity, treatments with the specific inhibitor of the PI3K LY294002 were carried out. The presence of LY294002 suppressed polarization of SMCs and prevented their asymmetrical division, whereas combined treatment with exogenously added NAA and LY294002 restricted the promotional auxin influence on subsidiary cell formation. These findings support the view that auxin is involved in Z. mays subsidiary cell formation, probably functioning as inducer of the asymmetrical SMC division. Collectively, the results obtained from treatments with auxin transport inhibitors and the appearance of PIN1 proteins in the lateral GMC faces indicate a local transfer of auxin from GMCs to SMCs. Moreover, auxin signal transduction seems to be mediated by the catalytic function of PI3K.

Auxin as an inducer of asymmetrical division generating the subsidiary cells in stomatal complexes of Zea mays

PubMed Central

Livanos, Pantelis; Giannoutsou, Eleni; Apostolakos, Panagiotis; Galatis, Basil

2015-01-01

The data presented in this work revealed that in Zea mays the exogenously added auxins indole-3-acetic acid (IAA) and 1-napthaleneacetic acid (NAA), promoted the establishment of subsidiary cell mother cell (SMC) polarity and the subsequent subsidiary cell formation, while treatment with auxin transport inhibitors 2,3,5-triiodobenzoic acid (TIBA) and 1-napthoxyacetic acid (NOA) specifically blocked SMC polarization and asymmetrical division. Furthermore, in young guard cell mother cells (GMCs) the PIN1 auxin efflux carriers were mainly localized in the transverse GMC faces, while in the advanced GMCs they appeared both in the transverse and the lateral ones adjacent to SMCs. Considering that phosphatidyl-inositol-3-kinase (PI3K) is an active component of auxin signal transduction and that phospholipid signaling contributes in the establishment of polarity, treatments with the specific inhibitor of the PI3K LY294002 were carried out. The presence of LY294002 suppressed polarization of SMCs and prevented their asymmetrical division, whereas combined treatment with exogenously added NAA and LY294002 restricted the promotional auxin influence on subsidiary cell formation. These findings support the view that auxin is involved in Z. mays subsidiary cell formation, probably functioning as inducer of the asymmetrical SMC division. Collectively, the results obtained from treatments with auxin transport inhibitors and the appearance of PIN1 proteins in the lateral GMC faces indicate a local transfer of auxin from GMCs to SMCs. Moreover, auxin signal transduction seems to be mediated by the catalytic function of PI3K. PMID:25831267

Reduced hippocampal N-acetyl-aspartate (NAA) as a biomarker for overweight.

PubMed

Coplan, Jeremy D; Fathy, Hassan M; Abdallah, Chadi G; Ragab, Sherif A; Kral, John G; Mao, Xiangling; Shungu, Dikoma C; Mathew, Sanjay J

2014-01-01

We previously demonstrated an inverse relationship between both dentate gyrus neurogenesis - a form of neuroplasticity - and expression of the antiapoptotic gene marker, BCL-2 and adult macaque body weight. We therefore explored whether a similar inverse correlation existed in humans between body mass index (BMI) and hippocampal N-acetyl-aspartate (NAA), a marker of neuronal integrity and putatively, neuroplasticity. We also studied the relationship of a potentially neurotoxic process, worry, to hippocampal NAA in patients with generalized anxiety disorder (GAD) and control subjects (CS). We combined two previously studied cohorts of GAD and control subjects. Using proton magnetic resonance spectroscopy imaging ((1)H MRSI) in medication-free patients with GAD (n = 29) and a matched healthy control group (n = 22), we determined hippocampal concentrations of (1) NAA (2) choline containing compounds (CHO), and (3) Creatine + phosphocreatine (CR). Data were combined from 1.5 T and 3 T scans by converting values from each cohort to z-scores. Overweight and GAD diagnosis were used as categorical variables while the Penn State Worry Questionnaire (PSWQ) and Anxiety Sensitivity Index (ASI) were used as dependent variables. Overweight subjects (BMI ≥ 25) exhibited lower NAA levels in the hippocampus than normal-weight subjects (BMI < 25) (partial Eta-squared = 0.14) controlling for age, sex and psychiatric diagnosis, and the effect was significant for the right hippocampus in both GAD patients and control subjects. An inverse linear correlation was noted in all subjects between right hippocampal NAA and BMI. High scores on the PSWQ predicted low hippocampal NAA and CR. Both BMI and worry were independent inverse predictors of hippocampal NAA. Overweight was associated with reduced NAA concentrations in the hippocampus with a strong effect size. Future mechanistic studies are warranted.

N-acetylaspartate (NAA) levels in selected areas of the brain in patients with chronic schizophrenia treated with typical and atypical neuroleptics: a proton magnetic resonance spectroscopy (1H MRS) study.

PubMed

Szulc, Agata; Galińska, Beata; Tarasów, Eugeniusz; Kubas, Bozena; Dzienis, Wojciech; Konarzewska, Beata; Poplawska, Regina; Tomczak, Anna A; Czernikiewicz, Andrzej; Walecki, Jerzy

2007-05-01

NAA, marker of neurons integrity and viability, is one of the most important brain metabolites visible in 1H MRS. In most studies of schizophrenia, the decrease of NAA level was observed in the temporal, frontal lobes and in the thalamus. This finding was observed more often among chronic patients, what suggests the influence of disease duration or the effect of neuroleptic treatment. The aim of the present study was the comparison of NAA levels in brain of schizophrenic patients taking typical and atypical neuroleptics. We analyzed the NAA levels in selected brain areas in 58 schizophrenic patients and 21 healthy controls. 10 patients were treated with typical neuroleptics, 10 patients with clozapine, 17 received olanzapine and 21 - risperidone. 1H MRS was performed on a 1,5 MR scanner with PRESS sequence. Voxels of 2x2x2 cm were localized in the left frontal, left temporal lobe and left thalamus. There were no differences in NAA levels between patients on typical and atypical medications analyzed together and separately (olanzapine, clozapine and risperidone groups). We also did not find any differences between patients taking selected atypical neuroleptics and controls. The NAA level in the thalamus in the group of patients receiving typical antipsychotics was the lowest among all groups and differed significantly from healthy controls. The results of our study suggest that atypical neuroleptics may have favorable effect on NAA concentration in brain of schizophrenic patients. Decrease in NAA level in patients taking typical medication may be caused by the progression of the disease or by the direct action of these drugs.

Neurochemical effects of quetiapine in patients with bipolar mania: a proton magnetic resonance spectroscopy study.

PubMed

Adler, Caleb M; DelBello, Melissa P; Weber, Wade A; Jarvis, Kelly B; Welge, Jeffrey; Chu, Wen-Jang; Rummelhoff, Emily; Kim, Mi-Jung; Lee, Jing-Huei; Strakowski, Stephen M

2013-08-01

Although the neurophysiology underlying pharmacotherapy for bipolar disorder remains poorly understood, recent studies suggest that therapeutic mechanisms may be reflected in changes in concentrations of N-acetylaspartate (NAA), a putative measure of neuronal integrity and metabolism. In this study, we used magnetic resonance spectroscopy (MRS) to examine prefrontal NAA in patients receiving quetiapine for bipolar mania. On the basis of previous findings, we hypothesized that remission would be associated with increased NAA concentrations in the prefrontal cortex. Thirty-one manic bipolar patients and 13 healthy subjects were recruited to participate in this prospective study. All subjects participated in MRS at baseline and after 8 weeks of treatment. Bipolar subjects received open-label quetiapine monotherapy (mean dose [SD], 584 [191] mg). Fourteen patients remitted (Young Mania Rating Scale ≤ 12) ("remitters"), 11 patients did not ("nonremitters"), and 6 patients were lost to follow-up. Bipolar and healthy subjects did not significantly differ in baseline NAA or degree of change during the 8 weeks. Remitters showed greater mean baseline NAA concentrations in the right ventrolateral prefrontal cortex compared with nonremitters (P < 0.05). In the anterior cingulate, remitters showed near significantly decreased baseline NAA concentrations at baseline (P < 0.06), and significant differences in NAA change during the 8 weeks of treatment (P < 0.03). Manic patients who remitted with quetiapine treatment in the course of this study exhibited distinct patterns of baseline prefrontal NAA concentration, coupled with decreased NAA in the anterior cingulate with treatment; the latter possibly reflecting disparate effects of quetiapine on neuronal metabolism. These data support suggestions that therapeutic effects of quetiapine involve metabolic effects on specific prefrontal regions.

Hypothalamic damage in multiple sclerosis correlates with disease activity, disability, depression, and fatigue.

PubMed

Kantorová, E; Poláček, H; Bittšanský, M; Baranovičová, E; Hnilicová, P; Čierny, D; Sivák, Š; Nosáľ, V; Zeleňák, K; Kurča, E

2017-04-01

Disturbances in the hypothalamo-pituitary axis are supposed to modulate activity of multiple sclerosis (MS). We hypothesised that the extent of HYP damage may determine severity of MS and may be associated with the disease evolution. We suggested fatigue and depression may depend on the degree of damage of the area. 33 MS patients with relapsing-remitting and secondary progressive disease, and 24 age and sex-related healthy individuals (CON) underwent 1H-MR spectroscopy (1H-MRS) of the hypothalamus. Concentrations of glutamate + glutamin (Glx), cholin (Cho), myoinositol (mIns), N-acetyl aspartate (NAA) expressed as ratio with creatine (Cr) and NAA were correlated with markers of disease activity (RIO score), Multiple Sclerosis Severity Scale (MSSS), Depressive-Severity Status Scale and Simple Numerical Fatigue Scale. Cho/Cr and NAA/Cr ratios were decreased and Glx/NAA ratio increased in MS patients vs CON. Glx/NAA, Glx/Cr, and mIns/NAA were significantly higher in active (RIO 1-2) vs non-active MS patients (RIO 0). Glx/NAA and Glx/Cr correlated with MSSS and fatigue score, and Glx/Cr with depressive score of MS patients. In CON, relationships between Glx/Cr and age, and Glx/NAA and fatigue score were inverse. Our study provides the first evidence about significant hypothalamic alterations correlating with clinical outcomes of MS, using 1H-MRS. The combination of increased Glu or mIns with reduced NAA in HYP reflects whole-brain activity of MS. In addition, excess of Glu is linked to severe disease course, depressive mood and fatigue in MS patients, suggesting superiority of Glu over other metabolites in determining MS burden.

Early Alzheimer's Disease Neuropathology Detected by Proton MR Spectroscopy

PubMed Central

Murray, Melissa E.; Przybelski, Scott A.; Lesnick, Timothy G.; Liesinger, Amanda M.; Spychalla, Anthony; Zhang, Bing; Gunter, Jeffrey L.; Parisi, Joseph E.; Boeve, Bradley F.; Knopman, David S.; Petersen, Ronald C.; Jack, Clifford R.; Dickson, Dennis W.

2014-01-01

Proton magnetic resonance spectroscopy (1H-MRS) is sensitive to early neurodegenerative processes associated with Alzheimer's disease (AD). Although 1H-MRS metabolite ratios of N-acetyl aspartate (NAA)/creatine (Cr), NAA/myoinositol (mI), and mI/Cr measured in the posterior cingulate gyrus reveal evidence of disease progression in AD, pathologic underpinnings of the 1H-MRS metabolite changes in AD are unknown. Pathologically diagnosed human cases ranging from no likelihood to high likelihood AD (n = 41, 16 females and 25 males) who underwent antemortem 1H-MRS of the posterior cingulate gyrus at 3 tesla were included in this study. Immunohistochemical evaluation was performed on the posterior cingulate gyrus using antibodies to synaptic vesicles, hyperphosphorylated tau (pTau), neurofibrillary tangle conformational-epitope (cNFT), amyloid-β, astrocytes, and microglia. The slides were digitally analyzed using Aperio software, which allows neuropathologic quantification in the posterior cingulate gray matter. MRS and pathology associations were adjusted for time from scan to death. Significant associations across AD and control subjects were found between reduced synaptic immunoreactivity and both NAA/Cr and NAA/mI in the posterior cingulate gyrus. Higher pTau burden was associated with lower NAA/Cr and NAA/mI. Higher amyloid-β burden was associated with elevated mI/Cr and lower NAA/mI ratios, but not with NAA/Cr. 1H-MRS metabolite levels reveal early neurodegenerative changes associated with AD pathology. Our findings support the hypothesis that a decrease in NAA/Cr is associated with loss of synapses and early pTau pathology, but not with amyloid-β or later accumulation of cNFT pathology in the posterior cingulate gyrus. In addition, elevation of mI/Cr is associated with the occurrence of amyloid-β plaques in AD. PMID:25471565

HERMES: Hadamard Encoding and Reconstruction of MEGA-Edited Spectroscopy

PubMed Central

Chan, Kimberly L.; Puts, Nicolaas A. J.; Schär, Michael; Barker, Peter B.; Edden, Richard A. E.

2017-01-01

Purpose To investigate a novel Hadamard-encoded spectral editing scheme and evaluate its performance in simultaneously quantifying N-acetyl aspartate (NAA) and N-acetyl aspartyl glutamate (NAAG) at 3 Tesla. Methods Editing pulses applied according to a Hadamard encoding scheme allow the simultaneous acquisition of multiple metabolites. The method, called HERMES (Hadamard Encoding and Reconstruction of MEGA-Edited Spectroscopy), was optimized to detect NAA and NAAG simultaneously using density-matrix simulations and validated in phantoms at 3T. In vivo data were acquired in the centrum semiovale of 12 normal subjects. The NAA:NAAG concentration ratio was determined by modeling in vivo data using simulated basis functions. Simulations were also performed for potentially coedited molecules with signals within the detected NAA/NAAG region. Results Simulations and phantom experiments show excellent segregation of NAA and NAAG signals into the intended spectra, with minimal crosstalk. Multiplet patterns show good agreement between simulations and phantom and in vivo data. In vivo measurements show that the relative peak intensities of the NAA and NAAG spectra are consistent with a NAA:NAAG concentration ratio of 4.22:1 in good agreement with literature. Simulations indicate some coediting of aspartate and glutathione near the detected region (editing efficiency: 4.5% and 78.2%, respectively, for the NAAG reconstruction and 5.1% and 19.5%, respectively, for the NAA reconstruction). Conclusion The simultaneous and separable detection of two otherwise overlapping metabolites using HERMES is possible at 3T. PMID:27089868

NAA and NAAG variation in neuronal activation during visual stimulation.

PubMed

Castellano, G; Dias, C S B; Foerster, B; Li, L M; Covolan, R J M

2012-11-01

N-acetyl-aspartyl-glutamate (NAAG) and its hydrolysis product N-acetyl-L-aspartate (NAA) are among the most important brain metabolites. NAA is a marker of neuron integrity and viability, while NAAG modulates glutamate release and may have a role in neuroprotection and synaptic plasticity. Investigating on a quantitative basis the role of these metabolites in brain metabolism in vivo by magnetic resonance spectroscopy (MRS) is a major challenge since the main signals of NAA and NAAG largely overlap. This is a preliminary study in which we evaluated NAA and NAAG changes during a visual stimulation experiment using functional MRS. The paradigm used consisted of a rest period (5 min and 20 s), followed by a stimulation period (10 min and 40 s) and another rest period (10 min and 40 s). MRS from 17 healthy subjects were acquired at 3T with TR/TE = 2000/288 ms. Spectra were averaged over subjects and quantified with LCModel. The main outcomes were that NAA concentration decreased by about 20% with the stimulus, while the concentration of NAAG concomitantly increased by about 200%. Such variations fall into models for the energy metabolism underlying neuronal activation that point to NAAG as being responsible for the hyperemic vascular response that causes the BOLD signal. They also agree with the fact that NAAG and NAA are present in the brain at a ratio of about 1:10, and with the fact that the only known metabolic pathway for NAAG synthesis is from NAA and glutamate.

Testing the applicability of the k0-NAA method at the MINT's TRIGA MARK II reactor

NASA Astrophysics Data System (ADS)

Siong, Wee Boon; Dung, Ho Manh; Wood, Ab. Khalik; Salim, Nazaratul Ashifa Abd.; Elias, Md. Suhaimi

2006-08-01

The Analytical Chemistry Laboratory at MINT is using the NAA technique since 1980s and is the only laboratory in Malaysia equipped with a research reactor, namely the TRIGA MARK II. Throughout the years the development of NAA technique has been very encouraging and was made applicable to a wide range of samples. At present, the k0 method has become the preferred standardization method of NAA ( k0-NAA) due to its multi-elemental analysis capability without using standards. Additionally, the k0 method describes NAA in physically and mathematically understandable definitions and is very suitable for computer evaluation. Eventually, the k0-NAA method has been adopted by MINT in 2003, in collaboration with the Nuclear Research Institute (NRI), Vietnam. The reactor neutron parameters ( α and f) for the pneumatic transfer system and for the rotary rack at various locations, as well as the detector efficiencies were determined. After calibration of the reactor and the detectors, the implemented k0 method was validated by analyzing some certified reference materials (including IAEA Soil 7, NIST 1633a, NIST 1632c, NIST 1646a and IAEA 140/TM). The analysis results of the CRMs showed an average u score well below the threshold value of 2 with a precision of better than ±10% for most of the elemental concentrations obtained, validating herewith the introduction of the k0-NAA method at the MINT.

The Association of Lung Function, Bronchial Hyperresponsiveness, and Exhaled Nitric Oxide Differs Between Atopic and Non-atopic Asthma in Children

PubMed Central

Shim, Eunhee; Lee, Eun; Yang, Song-I; Jung, Young-Ho; Park, Geun Mi; Kim, Hyung Young; Seo, Ju-Hee

2015-01-01

Purpose Although many previous studies have attempted to identify differences between atopic asthma (AA) and non-atopic asthma (NAA), they have mainly focused on the difference of each variable of lung function and airway inflammation. The aim of this study was to evaluate relationships between lung function, bronchial hyperresponsiveness (BHR), and the exhaled nitric oxide (eNO) levels in children with AA and NAA. Methods One hundred and thirty six asthmatic children aged 5-15 years and 40 normal controls were recruited. Asthma cases were classified as AA (n=100) or NAA (n=36) from skin prick test results. Lung function, BHR to methacholine and adenosine-5'-monophosphate (AMP), eNO, blood eosinophils, and serum total IgE were measured. Results The AA and NAA cases shared common features including a reduced small airway function and increased BHR to methacholine. However, children with AA showed higher BHR to AMP and eNO levels than those with NAA. When the relationships among these variables in the AA and NAA cases were evaluated, the AA group showed significant relationships between lung function, BHR to AMP or methacholine and eNO levels. However, the children in the NAA group showed an association between small airway function and BHR to methacholine only. Conclusions These findings suggest that the pathogenesis of NAA may differ from that of AA during childhood in terms of the relationship between lung function, airway inflammation and BHR. PMID:25749776

76 FR 73486 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-29

... (NAA) the application of a similar regulation. The aim of this [EASA] regulation is to require * * * a... Authorities] recommended to the National Aviation Authorities (NAA) the application of a similar regulation... Aviation Authorities (NAA) the application of a similar regulation. The aim of this [EASA] regulation is to...

76 FR 39035 - Airworthiness Directives; Airbus Model A310 Series Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-05

... application of a similar regulation to the National Aviation Authorities (NAA). Under this regulation, all... National Aviation Authorities (NAA). Under this regulation, all holders of type certificates for passenger... Authorities] JAA recommended the application of a similar regulation to the National Aviation Authorities (NAA...

Role of Natural Autoantibodies and Natural IgM Anti-Leucocyte Autoantibodies in Health and Disease

PubMed Central

Lobo, Peter Isaac

2016-01-01

We review how polyreactive natural IgM autoantibodies (IgM-NAA) protect the host from invading micro-organisms and host neo-antigens that are constantly being produced by oxidation mechanisms and cell apoptosis. Second, we discuss how IgM-NAA and IgM anti-leukocyte antibodies (IgM-ALA) inhibits autoimmune inflammation by anti-idiotypic mechanisms, enhancing removal of apoptotic cells, masking neo-antigens, and regulating the function of dendritic cells (DC) and effector cells. Third, we review how natural IgM prevents autoimmune disorders arising from pathogenic IgG autoantibodies, triggered by genetic mechanisms (e.g., SLE) or micro-organisms, as well as by autoreactive B and T cells that have escaped tolerance mechanisms. Studies in IgM knockout mice have clearly demonstrated that regulatory B and T cells require IgM to effectively regulate inflammation mediated by innate, adaptive, and autoimmune mechanisms. It is, therefore, not surprising why the host positively selects such autoreactive B1 cells that generate IgM-NAA, which are also evolutionarily conserved. Fourth, we show that IgM-ALA levels and their repertoire can vary in normal humans and disease states and this variation may partly explain the observed differences in the inflammatory response after infection, ischemic injury, or after a transplant. We also show how protective IgM-NAA can be rendered pathogenic under non-physiological conditions. We also review IgG-NAA that are more abundant than IgM-NAA in plasma. However, we need to understand if the (Fab)2 region of IgG-NAA has physiological relevance in non-disease states, as in plasma, their functional activity is blocked by IgM-NAA having anti-idiotypic activity. Some IgG-NAA are produced by B2 cells that have escaped tolerance mechanisms and we show how such pathogenic IgG-NAA are regulated to prevent autoimmune disease. The Fc region of IgG-NAA can influence inflammation and B cell function in vivo by binding to activating and inhibitory FcγR. IgM-NAA has therapeutic potential. Polyclonal IgM infusions can be used to abrogate on-going inflammation. Additionally, inflammation arising after ischemic kidney injury, e.g., during high-risk elective cardiac surgery or after allograft transplantation, can be prevented by pre-emptively infusing polyclonal IgM or DC pretreated ex vivo with IgM or by increasing in vivo IgM with a vaccine approach. Cell therapy is appealing as less IgM will be required. PMID:27375614

Non-Invasive Evaluation of the GABAergic/Glutamatergic System in Autistic Patients Observed by MEGA-Editing Proton MR Spectroscopy Using a Clinical 3 Tesla Instrument

ERIC Educational Resources Information Center

Harada, Masafumi; Taki, Masako M.; Nose, Ayumi; Kubo, Hitoshi; Mori, Kenji; Nishitani, Hiromu; Matsuda, Tsuyoshi

2011-01-01

Amino acids related to neurotransmitters and the GABAergic/glutamatergic system were measured using a 3 T-MRI instrument in 12 patients with autism and 10 normal controls. All measurements were performed in the frontal lobe (FL) and lenticular nuclei (LN) using a conventional sequence for n-acetyl aspartate (NAA) and glutamate (Glu), and the…

An efficient regeneration and rapid micropropagation protocol for Almond using dormant axillary buds as explants.

PubMed

Choudhary, Ravish; Chaudhury, Rekha; Malik, Surendra Kumar; Sharma, Kailash Chandra

2015-07-01

An efficient in vitro protocol was standardized for Almond (Prunus dulcis) propagation using dormant axillary buds as explants. Explants were cultured on Murashige and Skoog (MS) and woody plant medium (WPM) supplemented with different concentration/combination(s) of phytohormones. MS basal medium showed lowest shoot induction and took longest duration for shoot initiation. Multiple shoots were induced in MS medium supplemented with the combination of BAP (0.5 mgL(-1)). Cultures showed poor response for rooting in all combinations of plant growth regulators (PGRs) and took 90 days for initiation. Rooting was higher in half strength of MS than in full-strength. The highest root induction (33.33%) was recorded in half MS medium supplemented with 0.1 mgL(-1) IBA (indole-3-butyric acid) followed by full strength of MS medium (20%) supplemented with IBA (0.1 mgL(-1)). α-Naphthalene acetic acid (NAA) was less effective for rooting than IBA. The highest root induction (25%) was found in half strength of MS medium supplemented with 0.1 mgL(-1) NAA followed by full strength of MS medium (20%). The protocol developed would be of use in mass propagation of almond and also support in vitro conservation.

Nanoporous Anodic Alumina: A Versatile Platform for Optical Biosensors

PubMed Central

Santos, Abel; Kumeria, Tushar; Losic, Dusan

2014-01-01

Nanoporous anodic alumina (NAA) has become one of the most promising nanomaterials in optical biosensing as a result of its unique physical and chemical properties. Many studies have demonstrated the outstanding capabilities of NAA for developing optical biosensors in combination with different optical techniques. These results reveal that NAA is a promising alternative to other widely explored nanoporous platforms, such as porous silicon. This review is aimed at reporting on the recent advances and current stage of development of NAA-based optical biosensing devices. The different optical detection techniques, principles and concepts are described in detail along with relevant examples of optical biosensing devices using NAA sensing platforms. Furthermore, we summarise the performance of these devices and provide a future perspective on this promising research field. PMID:28788678

On the nature of the NAA diffusion attenuated MR signal in the central nervous system.

PubMed

Kroenke, Christopher D; Ackerman, Joseph J H; Yablonskiy, Dmitriy A

2004-11-01

In the brain, on a macroscopic scale, diffusion of the intraneuronal constituent N-acetyl-L-aspartate (NAA) appears to be isotropic. In contrast, on a microscopic scale, NAA diffusion is likely highly anisotropic, with displacements perpendicular to neuronal fibers being markedly hindered, and parallel displacements less so. In this report we first substantiate that local anisotropy influences NAA diffusion in vivo by observing differing diffusivities parallel and perpendicular to human corpus callosum axonal fibers. We then extend our measurements to large voxels within rat brains. As expected, the macroscopic apparent diffusion coefficient (ADC) of NAA is practically isotropic due to averaging of the numerous and diverse fiber orientations. We demonstrate that the substantially non-monoexponential diffusion-mediated MR signal decay vs. b value can be quantitatively explained by a theoretical model of NAA confined to an ensemble of differently oriented neuronal fibers. On the microscopic scale, NAA diffusion is found to be strongly anisotropic, with displacements occurring almost exclusively parallel to the local fiber axis. This parallel diffusivity, ADCparallel, is 0.36 +/- 0.01 microm2/ms, and ADCperpendicular is essentially zero. From ADCparallel the apparent viscosity of the neuron cytoplasm is estimated to be twice as large as that of a temperature-matched dilute aqueous solution. (c) 2004 Wiley-Liss, Inc.

MRS of pilocytic astrocytoma: The peak at 2 ppm may not be NAA.

PubMed

Tamrazi, Benita; Nelson, Marvin D; Blüml, Stefan

2017-08-01

To determine whether the chemical shift of residual N-acetylaspartate (NAA) signal in pilocytic astrocytomas (PA) is consistent with the position of the NAA peak in controls. MR spectra from 27 pediatric World Health Organization (WHO) grade I pilocytic astrocytoma patients, fifteen patients with WHO grade II and high-grade (III-IV) astrocytomas, and 36 controls were analyzed. All spectra were acquired with a short echo time (35 ms), single voxel point-resolved spectroscopy sequence on clinical 3 tesla scanners. Fully automated LCModel software was used for processing, which included the fitting of peak positions for NAA and creatine (Cr). The chemical shift difference between the NAA and Cr peaks was significantly smaller (by 0.016 ± 0.005 parts per million, P < 1e-10) in PAs than in controls and was also smaller than what was observed in infiltrative astrocytomas. The chemical shift position of the residual NAA peak in PAs is not consistent with NAA. The signal likely originates from an N-acetyl group of one or more other chemicals such as N-acetylated sugars. Magn Reson Med 78:452-456, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Somatic embryogenesis, pigment accumulation, and synthetic seed production in Digitalis davisiana Heywood.

PubMed

Verma, Sandeep Kumar; Sahin, Gunce; Gurel, Ekrem

2016-04-01

Digitalis davisiana, commonly called Alanya foxglove, from Turkey, is an important medicinal herb as the main source of cardiac glycosides, cardenolides, anthraquinones, etc. It is also known in the Indian Medicine for treatment of wounds and burns. It has ornamental value as well. Overexploitation of D. davisiana has led this species to be declared protected, and thereby encouraged various methods for its propagation. In this study, an optimized and efficient plant tissue culture protocol was established using cotyledonary leaf, hypocotyl and root explants of D. davisiana. Callus tissues were obtained from the cotyledonary leaf, hypocotyl and root segments cultured on Murashige and Skoog's (MS) medium containing different plant growth regulators. The maximum number of somatic embryos were achieved by the MS medium containing 6-benzyladenine (1.0 mg/L BAP) or 2,4-dichlorophenoxy acetic acids (0.1 mg/L 2,4-D), which produced an average of 8.3 ± 1.5 or 5.3 ± 1.5 embryos per cotyledonary leaf, respectively. After 3 wk of culture in MS medium supplemented with 1.0 mg/L 2,4-D, callus showed a clear accumulation of orange pigmentation. Shoot regeneration was remarkably higher (14.3 indirect shoots) in a combination of α-naphthalene acetic acid (0.25 mg/L NAA) plus 3.0 mg/L BAP than 2.0 mg/L zeatin (10.3 ± 0.5 direct shoots) alone. The shoots were successfully rooted on MS medium supplemented with NAA (0.1-1.0 mg/L). In addition, synthetic seeds were produced by encapsulating shoot tips in 4% sodium alginate solution. Maximum conversion frequency of 76.6% was noted from encapsulated shoot tips cultured on 0.25 mg/L NAA with 1.0 mg/L BAP. The encapsulated shoot tips could be stored up to 60 days at 4 °C. Regenerated plantlets of D. davisiana were successfully acclimatized and transferred to soil. This study has demonstrated successful preservation of elite genotypes of D. davisiana.

Effect of AgNO3 and BAP on Root as a Novel Explant in Date Palm (Phoenix dactylifera cv. Medjool) Somatic Embryogenesis.

PubMed

Roshanfekrrad, Marjan; Zarghami, Reza; Hassani, Hassan; Zakizadeh, Hedayat; Salari, Ali

2017-01-01

Somatic embryogenesis techniques are used for cloning a wide range of varieties of date palms around the world. The aim of the present study was to develop an efficient method with the lowest cost and the greatest potential to obtain in vitro plantlets of date palm cv. Medjool. Also, produce embryogenic callus and somatic embryos without using 2,4-dichlorophenoxyacetic acid (2,4-D). In this study, produced plantlets through somatic embryogenesis were used in vitro roots as explant cultured on Murashige and Skoog (MS) media containing three level of Silver Nitrate (AgNO3) (0, 3 and 6 mg L-1) plus two level of 6-benzylaminopurine (BAP) (0 and 2 mg L-1) plus 0.1 mg L-1 1-naphthylacetic acid (NAA) for callus induction. After 12 weeks of culture, callus induction and after 16 weeks, production of embryogenic callus and embryos were occurred from root explants. According to the results, medium containing 2 mg L-1 BAP and 3 mg L-1 silver nitrate+0.1 mg L-1 NAA showed the highest amount of embryogenic callus fresh weight (1.38 g). This treatment also cause the highest number and length of embryos by production of 90.04 embryogenic callus with length of 11.18 mm. On the other hand, shoots were appeared from germinated embryos and white roots began to appear within 8 weeks. Medium contains 3 mg L-1 BAP and 0.1 mg L-1 NAA with average of 12.27 cm shoot length and 15.48 cm root length was the best. Control treatment had the lowest average shoot (3.71 cm) and root (5.03 cm) length. This study showed that certain concentration of silver nitrate and BAP has stimulating effect on growth of produced embryonic callus from root segments of Medjool cultivar of date palm.

Differences between Spinocerebellar Ataxias and Multiple System Atrophy-Cerebellar Type on Proton Magnetic Resonance Spectroscopy

PubMed Central

Chen, Hung-Chieh; Soong, Bing-Wen; Guo, Wan Yuo; Wu, Hsiu-Mei; Chang, Cheng-Yen

2012-01-01

Purpose A broad spectrum of diseases can manifest cerebellar ataxia. In this study, we investigated whether proton magnetic resonance spectroscopy (MRS) may help differentiate spinocerebellar ataxias (SCA) from multiple systemic atrophy- cerebellar type (MSA-C). Material and Methods This prospective study recruited 156 patients with ataxia, including spinocerebellar ataxia (SCA) types 1, 2, 3, 6 and 17 (N = 94) and MSA-C (N = 62), and 44 healthy controls. Single voxel proton MRS in the cerebellar hemispheres and vermis were measured. The differences were evaluated using nonparametric statistic tests. Results When compared with healthy controls, the cerebellar and vermis NAA/Cr and NAA/Cho were lower in all patients(p<0.002). The Cho/Cr was lower in SCA2 and MSA-C (p<0.0005). The NAA/Cr and Cho/Cr were lower in MSA-C or SCA2 comparing with SCA3 or SCA6. The MRS features of SCA1 were in between (p<0.018). The cerebellar NAA/Cho was lower in SCA2 than SCA1, SCA3 or SCA6 (p<0.04). The cerebellar NAA/Cho in MSA-C was lower than SCA3 (p<0.0005). In the early stages of diseases (SARA score<10), significant lower NAA/Cr and NAA/Cho in SCA2, SCA3, SCA6 or MSA-C were observed comparing with healthy controls (p<0.017). The Cho/Cr was lower in MSA-C or SCA2 (p<0.0005). Patients with MSA-C and SCA2 had lower NAA/Cr and Cho/Cr than SCA3 or SCA6 (p<0.016). Conclusion By using MRS, significantly lower NAA/Cr, Cho/Cr and NAA/Cho in the cerebellar hemispheres and vermis were found in patients with ataxia (SCAs and MSA-C). Rapid neuronal degeneration and impairment of membrane activities were observed more often in patients with MSA-C than those with SCA, even in early stages. MRS could also help distinguish between SCA2 and other subtypes of SCAs. MRS ratios may be of use as biomarkers in early stages of disease and should be further assessed in a longitudinal study. PMID:23118909

Chronic treatment with lithium, but not sodium valproate, increases cortical N-acetyl-aspartate concentrations in euthymic bipolar patients.

PubMed

Silverstone, Peter H; Wu, Ren H; O'Donnell, Tina; Ulrich, Michele; Asghar, Sheila J; Hanstock, Christopher C

2003-03-01

Previous studies have found that treatment with lithium over a 4-week period may increase the concentration of N-acetyl-aspartate (NAA) in both bipolar patients and controls. In view of other findings indicating that NAA concentrations may be a good marker for neuronal viability and/or functioning, it has been further suggested that some of the long term benefits of lithium may therefore be due to actions to improve these neuronal properties. The aim of the present study was to utilize H magnetic resonance spectroscopy ( H MRS) to further examine the effects of both lithium and sodium valproate upon NAA concentrations in treated euthymic bipolar patients. In the first part of the study, healthy controls (n =18) were compared with euthymic bipolar patients (type I and type II) who were taking either lithium (n =14) or sodium valproate (n =11), and NAA : creatine ratios were determined. In the second part, we examined a separate group of euthymic bipolar disorder patients taking sodium valproate (n =9) and compared these to age- and sex-matched healthy controls (n =11), and we quantified the exact concentrations of NAA using an external solution. The results from the first part of the study showed that bipolar patients chronically treated with lithium had a significant increase in NAA concentrations but, in contrast, there were no significant increases in the sodium valproate-treated patients compared to controls. The second part of the study also found no effects of sodium valproate on NAA concentrations. These findings are the first to compare NAA concentrations in euthymic bipolar patients being treated with lithium or sodium valproate. The results support suggestions that longer-term administration of lithium to bipolar patients may increase NAA concentrations. However, the study suggests that chronic administration of sodium valproate to patients does not lead to similar changes in NAA concentrations. These findings suggest that sodium valproate and lithium may not share a common mechanism of action in bipolar disorder involving neurotrophic or neuroprotective effects.

Investigation of NAA and NAAG dynamics underlying visual stimulation using MEGA-PRESS in a functional MRS experiment

PubMed Central

Landim, Ricardo C.G.; Edden, Richard A.E.; Foerster, Bernd; Li, Li Min; Covolan, Roberto J.M.; Castellano, Gabriela

2017-01-01

N-acetyl-aspartate (NAA) is responsible for the majority of the most prominent peak in 1H-MR spectra, and has been used as diagnostic marker for several pathologies. However, ~10% of this peak can be attributed to N-acetyl-aspartyl-glutamate (NAAG), a neuropeptide whose release may be triggered by intense neuronal activation. Separate measurement of NAA and NAAG using MRS is difficult due to large superposition of their spectra. Specifically, in functional MRS (fMRS) experiments, most work has evaluated the sum NAA + NAAG, which does not appear to change during experiments. The aim of this work was to design and perform an fMRS experiment using visual stimulation and a spectral editing sequence, MEGA-PRESS, to further evaluate the individual dynamics of NAA and NAAG during brain activation. The functional paradigm used consisted of three blocks, starting with a rest (baseline) block of 320 s, followed by a stimulus block (640 s) and a rest block (640 s). Twenty healthy subjects participated in this study. On average, subjects followed a pattern of NAA decrease and NAAG increase during stimulation, with a tendency to return to basal levels at the end of the paradigm, with a peak NAA decrease of −(21 ± 19)% and a peak NAAG increase of (64 ± 62)% (Wilcoxon test, p < 0.05). These results may relate to: 1) the only known NAAG synthesis pathway is from NAA and glutamate; 2) a relationship between NAAG and the BOLD response. PMID:26656908

Investigation of NAA and NAAG dynamics underlying visual stimulation using MEGA-PRESS in a functional MRS experiment.

PubMed

Landim, Ricardo C G; Edden, Richard A E; Foerster, Bernd; Li, Li Min; Covolan, Roberto J M; Castellano, Gabriela

2016-04-01

N-acetyl-aspartate (NAA) is responsible for the majority of the most prominent peak in (1)H-MR spectra, and has been used as diagnostic marker for several pathologies. However, ~10% of this peak can be attributed to N-acetyl-aspartyl-glutamate (NAAG), a neuropeptide whose release may be triggered by intense neuronal activation. Separate measurement of NAA and NAAG using MRS is difficult due to large superposition of their spectra. Specifically, in functional MRS (fMRS) experiments, most work has evaluated the sum NAA+NAAG, which does not appear to change during experiments. The aim of this work was to design and perform an fMRS experiment using visual stimulation and a spectral editing sequence, MEGA-PRESS, to further evaluate the individual dynamics of NAA and NAAG during brain activation. The functional paradigm used consisted of three blocks, starting with a rest (baseline) block of 320 s, followed by a stimulus block (640 s) and a rest block (640 s). Twenty healthy subjects participated in this study. On average, subjects followed a pattern of NAA decrease and NAAG increase during stimulation, with a tendency to return to basal levels at the end of the paradigm, with a peak NAA decrease of -(21±19)% and a peak NAAG increase of (64±62)% (Wilcoxon test, p<0.05). These results may relate to: 1) the only known NAAG synthesis pathway is from NAA and glutamate; 2) a relationship between NAAG and the BOLD response. Copyright © 2015 Elsevier Inc. All rights reserved.

Decreased NAA in gray matter is correlated with decreased availability of acetate in white matter in postmortem multiple sclerosis cortex.

PubMed

Li, S; Clements, R; Sulak, M; Gregory, R; Freeman, E; McDonough, J

2013-11-01

Multiple sclerosis (MS) is an inflammatory neurodegenerative disease of the central nervous system (CNS) which leads to progressive neurological disability. Our previous studies have demonstrated mitochondrial involvement in MS cortical pathology and others have documented decreased levels of the neuronal mitochondrial metabolite N-acetyl aspartate (NAA) in the MS brain. While NAA is synthesized in neurons, it is broken down in oligodendrocytes into aspartate and acetate. The resulting acetate is incorporated into myelin lipids, linking neuronal mitochondrial function to oligodendrocyte-mediated elaboration of myelin lipids in the CNS. In the present study we show that treating human SH-SY5Y neuroblastoma cells with the electron transport chain inhibitor antimycin A decreased levels of NAA as measured by HPLC. To better understand the significance of the relationship between mitochondrial function and levels of NAA and its breakdown product acetate on MS pathology we then quantitated the levels of NAA and acetate in MS and control postmortem tissue blocks. Regardless of lesion status, we observed that levels of NAA were decreased 25 and 32 % in gray matter from parietal and motor cortex in MS, respectively, compared to controls. Acetate levels in adjacent white matter mirrored these decreases as evidenced by the 36 and 45 % reduction in acetate obtained from parietal and motor cortices. These data suggest a novel mechanism whereby mitochondrial dysfunction and reduced NAA levels in neurons may result in compromised myelination by oligodendrocytes due to decreased availability of acetate necessary for the synthesis of myelin lipids.

Decreased NAA in Gray Matter is Correlated with Decreased Availability of Acetate in White Matter in Postmortem Multiple Sclerosis Cortex

PubMed Central

Li, S.; Clements, R.; Sulak, M.; Gregory, R.; Freeman, E.; McDonough, J.

2013-01-01

Multiple sclerosis (MS) is an inflammatory neurodegenerative disease of the central nervous system (CNS) which leads to progressive neurological disability. Our previous studies have demonstrated mitochondrial involvement in MS cortical pathology and others have documented decreased levels of the neuronal mitochondrial metabolite N-acetyl aspartate (NAA) in the MS brain. While NAA is synthesized in neurons, it is broken down in oligodendrocytes into aspartate and acetate. The resulting acetate is incorporated into myelin lipids, linking neuronal mitochondrial function to oligodendrocyte-mediated elaboration of myelin lipids in the CNS. In the present study we show that treating human SH-SY5Y neuroblastoma cells with the electron transport chain inhibitor antimycin A decreased levels of NAA as measured by HPLC. To better understand the significance of the relationship between mitochondrial function and levels of NAA and its breakdown product acetate on MS pathology we then quantitated the levels of NAA and acetate in MS and control postmortem tissue blocks. Regardless of lesion status, we observed that levels of NAA were decreased 25 and 32 % in gray matter from parietal and motor cortex in MS, respectively, compared to controls. Acetate levels in adjacent white matter mirrored these decreases as evidenced by the 36 and 45 % reduction in acetate obtained from parietal and motor cortices. These data suggest a novel mechanism whereby mitochondrial dysfunction and reduced NAA levels in neurons may result in compromised myelination by oligodendrocytes due to decreased availability of acetate necessary for the synthesis of myelin lipids. PMID:24078261

78 FR 20001 - Approval and Promulgation of Implementation Plans; Idaho: Sandpoint PM10

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-03

... (Sandpoint NAA) for particulate matter with an aerodynamic diameter less than or equal to a nominal 10... NAA LMP that does not meet LMP eligibility criteria or applicable requirements under the Clean Air Act (CAA). The part of the Sandpoint NAA LMP that the EPA is approving complies with applicable...

NAA thinning of ‘W. Murcott’

USDA-ARS?s Scientific Manuscript database

This study was conducted to determine if NAA thinning may be useful for managing cropload in Florida ‘W Murcott’. Trials were conducted in two groves of ages 4 and 6 years. NAA was applied on 13 May, 2010, when fruitlets averaged 10-12 mm in diameter. A randomized complete block design was used, ...

The use of amino acid indices for assessing organic matter quality and microbial abundance in deep-sea Antarctic sediments of IODP Expedition 318

USGS Publications Warehouse

Carr, Stephanie A; Mills, Christopher T.; Mandernack, Kevin W

2016-01-01

The Adélie Basin, located offshore of the Wilkes Land margin, experiences unusually high sedimentation rates (~ 2 cm yr− 1) for the Antarctic coast. This study sought to compare depthwise changes in organic matter (OM) quantity and quality with changes in microbial biomass with depth at this high-deposition site and an offshore continental margin site. Sediments from both sites were collected during the International Ocean Drilling (IODP) Program Expedition 318. Viable microbial biomass was estimated from concentrations of bacterial-derived phospholipid fatty acids, while OM quality was assessed using four different amino acid degradation proxies. Concentrations of total hydrolysable amino acids (THAA) measured from the continental margin suggest an oligotrophic environment, with THAA concentrations representing only 2% of total organic carbon with relative proportions of non-protein amino acids β-alanine and γ-aminobutyric acid as high as 40%. In contrast, THAA concentrations from the near-shore Adélie Basin represent 40%–60% of total organic carbon. Concentrations of β-alanine and γ-aminobutyric acid were often below the detection limit and suggest that the OM of the basin as labile. DI values in surface sediments at the Adélie and margin sites were measured to be + 0.78 and − 0.76, reflecting labile and more recalcitrant OM, respectively. Greater DI values in deeper and more anoxic portions of both cores correlated positively with increased relative concentrations of phenylalanine plus tyrosine and may represent a change of redox conditions, rather than OM quality. This suggests that DI values calculated along chemical profiles should be interpreted with caution. THAA concentrations, the percentage of organic carbon (CAA%) and total nitrogen (NAA%) represented by amino acids at both sites demonstrated a significant positive correlation with bacterial abundance estimates. These data suggest that the selective degradation of amino acids, as indicated by THAA concentrations, CAA% or NAA% values may be a better proxy for describing the general changes in sedimentary bacterial abundances than total organic matter or bulk sedimentation rates.

Reduced hippocampal N-acetyl-aspartate (NAA) as a biomarker for overweight☆

PubMed Central

Coplan, Jeremy D.; Fathy, Hassan M.; Abdallah, Chadi G.; Ragab, Sherif A.; Kral, John G.; Mao, Xiangling; Shungu, Dikoma C.; Mathew, Sanjay J.

2014-01-01

Objective We previously demonstrated an inverse relationship between both dentate gyrus neurogenesis – a form of neuroplasticity – and expression of the antiapoptotic gene marker, BCL-2 and adult macaque body weight. We therefore explored whether a similar inverse correlation existed in humans between body mass index (BMI) and hippocampal N-acetyl-aspartate (NAA), a marker of neuronal integrity and putatively, neuroplasticity. We also studied the relationship of a potentially neurotoxic process, worry, to hippocampal NAA in patients with generalized anxiety disorder (GAD) and control subjects (CS). Methods We combined two previously studied cohorts of GAD and control subjects. Using proton magnetic resonance spectroscopy imaging (1H MRSI) in medication-free patients with GAD (n = 29) and a matched healthy control group (n = 22), we determined hippocampal concentrations of (1) NAA (2) choline containing compounds (CHO), and (3) Creatine + phosphocreatine (CR). Data were combined from 1.5 T and 3 T scans by converting values from each cohort to z-scores. Overweight and GAD diagnosis were used as categorical variables while the Penn State Worry Questionnaire (PSWQ) and Anxiety Sensitivity Index (ASI) were used as dependent variables. Results Overweight subjects (BMI ≥ 25) exhibited lower NAA levels in the hippocampus than normal-weight subjects (BMI < 25) (partial Eta-squared = 0.14) controlling for age, sex and psychiatric diagnosis, and the effect was significant for the right hippocampus in both GAD patients and control subjects. An inverse linear correlation was noted in all subjects between right hippocampal NAA and BMI. High scores on the PSWQ predicted low hippocampal NAA and CR. Both BMI and worry were independent inverse predictors of hippocampal NAA. Conclusion Overweight was associated with reduced NAA concentrations in the hippocampus with a strong effect size. Future mechanistic studies are warranted. PMID:24501701

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chatt, A.

The 60th anniversary of the discovery of neutron activation analysis (NAA) by Hevesy and Levi is being celebrated in 1996. With the availability of nuclear reactors capable of producing fluxes of the order of 10{sup 12} to 10{sup 14} n/cm{sup 2}s, the development of high-resolution and high-efficiency conventional and anticoincidence gamma-ray detectors, multichannel pulse-height analyzers, and personal computer-based softwares, NAA has become an extremely valuable analytical technique, especially for the simultaneous determinations of multielement concentrations. This technique can be used in a number of ways, depending on the nature of the matrix, the major elements in the sample, and onmore » the elements of interest. In most cases, several elements can be determined without any chemical pretreatment of the sample; the technique is then called instrumental NAA (INAA). In other cases, an element can be concentrated from an interfering matrix prior to irradiation; the technique is then termed preconcentration NAA (PNAA). In opposite instances, the irradiation is followed by a chemical separation of the desired element; the technique is then called radiochemical NAA (RNAA). All three forms of NAA can provide elemental concentrations of high accuracy and precision with excellent sensitivity. The number of research reactors in developing countries has increased steadily from 17 in 1955 through 71 in 1975 to 89 in 1995. Low flux reactors such as SLOWPOKE and the Chinese MNSR are primarily used for NAA.« less

Proton Magnetic Resonance Spectroscopy Study on the Metabolism Changes of Cerebellum in Patients with Post-Stroke Depression.

PubMed

Zhang, Lei; Sui, Ru-Bo

2017-01-01

To study the metabolic changes of cerebellum by proton magnetic resonance Spectroscopy (1H-MRS) and discuss the relationships between the cerebellar changes and depression severity in patients with post-stroke depression. Data of demographic characteristics, individual history and life style of all subjects were collected. 40 patients with stroke and 20 controls were enrolled. All groups received T1WI, T2WI, DWI and 1H-MRS examination. The cerebral infarction volume and the distribution and severity of leukoaraiosis were evaluated. The ratios of NAA/Cr, Cho/Cr and Cho/NAA in the cerebellum were calculated. There were no statistical significant difference in the NAA/Cr, Cho/Cr and Cho/NAA ratios in bilateral cerebellum between CONT group and NORM group. The Cho/Cr and Cho/NAA ratios in the cerebellum contralateral to the stroke region were higher in PSD group than those in NORM and CONT groups, and the Cho/Cr and Cho/NAA ratios in the cerebellum ipsilateral to the stroke region were similar with those in NORM and CONT groups. However, there were no statistical significant difference in the NAA/Cr ratios in bilateral cerebellum among three groups. The result shows preliminarily that the cerebellum involves in the development of post-stroke depression. © 2017 The Author(s). Published by S. Karger AG, Basel.

78 FR 67952 - Approval and Promulgation of Implementation Plans; Mississippi; Transportation Conformity SIP...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-13

... effective date of the nonattainment area (NAA) designations. See 40 CFR 51.390(c). On April 30, 2012, EPA... in the 8- hour ozone Memphis NAA.\\2\\ The Memphis Urban Area MPO \\3\\ is within the Memphis Area and is... and/or update their respective transportation conformity SIPs for the Memphis NAA in separate...

20 CFR 663.515 - What is the process for initial determination of provider eligibility?

Code of Federal Regulations, 2010 CFR

2010-04-01

... the National Apprenticeship Act (NAA), and the providers or such programs, Local Boards determine the... the HEA or registered under the NAA, and for providers not eligible under title IV of the HEA or carrying out apprenticeship programs under NAA: (1) The Governor must develop a procedure for use by Local...

Characterization of Human Aspartoacylase: the brain enzyme responsible for Canavan disease†

PubMed Central

Le Coq, Johanne; An, Hyun-Joo; Lebrilla, Carlito; Viola, Ronald E.

2008-01-01

Aspartoacylase catalyzes the deacetylation of N-acetylaspartic acid (NAA) to produce acetate and L-aspartate, and is the only brain enzyme that has been shown to effectively metabolize NAA. Although the exact role of this enzymatic reaction has not yet been completely elucidated, the metabolism of NAA appears to be necessary in the formation of myelin lipids and defects in this enzyme lead to Canavan disease, a fatal neurological disorder. The low catalytic activity and inherent instability observed with the Escherichia coli-expressed form of aspartoacylase suggested the need for a suitable eukaryotic expression system that would be capable of producing a fully functional, mature enzyme. Human aspartoacylase has now been successfully expressed in Pichia pastoris. While the expression yields are lower than in E. coli, the purified enzyme is significantly more stable. This enzyme form has the same substrate specificity, but is 150-fold more active than the E. coli-expressed enzyme. The molecular weight of the purified enzyme, measured by mass spectrometry, is higher than predicted, suggesting the presence of some posttranslational modifications. Deglycosylation of aspartoacylase or mutation at the glycosylation site causes decreased enzyme stability and diminished catalytic activity. A carbohydrate component has been removed and characterized by mass spectrometry. In addition to this carbohydrate moiety, the enzyme has also been shown to contain one zinc atom per subunit. Chelation studies to remove the zinc results in a reversible loss of catalytic activity, thus establishing aspartoacylase as a zinc metalloenzyme. PMID:16669630

Characterization of human aspartoacylase: the brain enzyme responsible for Canavan disease.

PubMed

Le Coq, Johanne; An, Hyun-Joo; Lebrilla, Carlito; Viola, Ronald E

2006-05-09

Aspartoacylase catalyzes the deacetylation of N-acetylaspartic acid (NAA) to produce acetate and L-aspartate and is the only brain enzyme that has been shown to effectively metabolize NAA. Although the exact role of this enzymatic reaction has not yet been completely elucidated, the metabolism of NAA appears to be necessary in the formation of myelin lipids, and defects in this enzyme lead to Canavan disease, a fatal neurological disorder. The low catalytic activity and inherent instability observed with the Escherichia coli-expressed form of aspartoacylase suggested the need for a suitable eukaryotic expression system that would be capable of producing a fully functional, mature enzyme. Human aspartoacylase has now been successfully expressed in Pichia pastoris. While the expression yields are lower than in E. coli, the purified enzyme is significantly more stable. This enzyme form has the same substrate specificity but is 150-fold more active than the E. coli-expressed enzyme. The molecular weight of the purified enzyme, measured by mass spectrometry, is higher than predicted, suggesting the presence of some post-translational modifications. Deglycosylation of aspartoacylase or mutation at the glycosylation site causes decreased enzyme stability and diminished catalytic activity. A carbohydrate component has been removed and characterized by mass spectrometry. In addition to this carbohydrate moiety, the enzyme has also been shown to contain one zinc atom per subunit. Chelation studies to remove the zinc result in a reversible loss of catalytic activity, thus establishing aspartoacylase as a zinc metalloenzyme.

Cancer-specific production of N-acetylaspartate via NAT8L overexpression in non-small cell lung cancer and its potential as a circulating biomarker

PubMed Central

Lou, Tzu-Fang; Sethuraman, Deepa; Dospoy, Patrick; Srivastva, Pallevi; Kim, Hyun Seok; Kim, Joongsoo; Ma, Xiaotu; Chen, Pei-Hsuan; Huffman, Kenneth E.; Frink, Robin E.; Larsen, Jill E.; Lewis, Cheryl; Um, Sang-Won; Kim, Duk-Hwan; Ahn, Jung-Mo; DeBerardinis, Ralph J.; White, Michael A.; Minna, John D.; Yoo, Hyuntae

2015-01-01

In order to identify new cancer-associated metabolites that may be useful for early detection of lung cancer, we performed a global metabolite profiling of a non-small cell lung cancer (NSCLC) line and immortalized normal lung epithelial cells from the same patient. Among several metabolites with significant cancer/normal differences, we identified a unique metabolic compound, N-acetylaspartate (NAA) in cancer cells — undetectable in normal lung epithelium. NAA’s cancer-specific detection was validated in additional cancer and control lung cells as well as selected NSCLC patient tumors and control tissues. NAA’s cancer-specificity was further supported in our analysis of NAA synthetase (gene symbol: NAT8L) gene expression levels in The Cancer Genome Atlas: elevated NAT8L expression in approximately 40% of adenocarcinoma and squamous cell carcinoma cases (N=577), with minimal expression in all non-malignant lung tissues (N=74). We then showed that NAT8L is functionally involved in NAA production of NSCLC cells through siRNA-mediated suppression of NAT8L, which caused selective reduction of intracellular and secreted NAA. Our cell culture experiments also indicated that NAA biosynthesis in NSCLC cells depends on glutamine availability. For preliminary evaluation of NAA’s clinical potential as a circulating biomarker, we developed a sensitive NAA blood assay and found that NAA blood levels were elevated in 46% of NSCLC patients (N=13) in comparison with age-matched healthy controls (N=21) among individuals aged 55 years or younger. Taken together, these results indicate that NAA is produced specifically in NSCLC tumors through NAT8L overexpression and its extracellular secretion can be detected in blood. PMID:26511490

Magnetic zeolite NaA: synthesis, characterization based on metakaolin and its application for the removal of Cu2+, Pb2+.

PubMed

Liu, Haibo; Peng, Shuchuan; Shu, Lin; Chen, Tianhu; Bao, Teng; Frost, Ray L

2013-06-01

The optimum parameters for synthesis of zeolite NaA based on metakaolin were investigated according to results of cation exchange capacity and static water adsorption of all synthesis products and selected X-ray diffraction (XRD). Magnetic zeolite NaA was synthesized by adding Fe3O4 in the precursor of zeolite. Zeolite NaA and magnetic zeolite NaA were characterized with scanning electron microscopy (SEM) and XRD. Magnetic zeolite NaA with different Fe3O4 loadings was prepared and used for removal of heavy metals (Cu(2+), Pb(2+)). The results show the optimum parameters for synthesis zeolite NaA are SiO2/Al2O3=2.3, Na2O/SiO2=1.4, H2O/Na2O=50, crystallization time 8h, crystallization temperature 95 °C. The addition of Fe3O4 makes the NaA zeolite with good magnetic susceptibility and good magnetic stability regardless of the Fe3O4 loading, confirming the considerable separation efficiency. Additionally, Fe3O4 loading had a little effect on removal of heavy metal by magnetic zeolite, however, the adsorption capacity still reaches 2.3 mmol g(-1) for Cu(2+), Pb(2+) with a removal efficiency of over 95% in spite of 4.7% Fe3O4 loading. This indicates magnetic zeolite can be used to remove metal heavy at least Cu(2+), Pb(2+) from water with metallic contaminants and can be separated easily after a magnetic process. Copyright © 2013 Elsevier Ltd. All rights reserved.

Truncating Variants in NAA15 Are Associated with Variable Levels of Intellectual Disability, Autism Spectrum Disorder, and Congenital Anomalies.

PubMed

Cheng, Hanyin; Dharmadhikari, Avinash V; Varland, Sylvia; Ma, Ning; Domingo, Deepti; Kleyner, Robert; Rope, Alan F; Yoon, Margaret; Stray-Pedersen, Asbjørg; Posey, Jennifer E; Crews, Sarah R; Eldomery, Mohammad K; Akdemir, Zeynep Coban; Lewis, Andrea M; Sutton, Vernon R; Rosenfeld, Jill A; Conboy, Erin; Agre, Katherine; Xia, Fan; Walkiewicz, Magdalena; Longoni, Mauro; High, Frances A; van Slegtenhorst, Marjon A; Mancini, Grazia M S; Finnila, Candice R; van Haeringen, Arie; den Hollander, Nicolette; Ruivenkamp, Claudia; Naidu, Sakkubai; Mahida, Sonal; Palmer, Elizabeth E; Murray, Lucinda; Lim, Derek; Jayakar, Parul; Parker, Michael J; Giusto, Stefania; Stracuzzi, Emanuela; Romano, Corrado; Beighley, Jennifer S; Bernier, Raphael A; Küry, Sébastien; Nizon, Mathilde; Corbett, Mark A; Shaw, Marie; Gardner, Alison; Barnett, Christopher; Armstrong, Ruth; Kassahn, Karin S; Van Dijck, Anke; Vandeweyer, Geert; Kleefstra, Tjitske; Schieving, Jolanda; Jongmans, Marjolijn J; de Vries, Bert B A; Pfundt, Rolph; Kerr, Bronwyn; Rojas, Samantha K; Boycott, Kym M; Person, Richard; Willaert, Rebecca; Eichler, Evan E; Kooy, R Frank; Yang, Yaping; Wu, Joseph C; Lupski, James R; Arnesen, Thomas; Cooper, Gregory M; Chung, Wendy K; Gecz, Jozef; Stessman, Holly A F; Meng, Linyan; Lyon, Gholson J

2018-05-03

N-alpha-acetylation is a common co-translational protein modification that is essential for normal cell function in humans. We previously identified the genetic basis of an X-linked infantile lethal Mendelian disorder involving a c.109T>C (p.Ser37Pro) missense variant in NAA10, which encodes the catalytic subunit of the N-terminal acetyltransferase A (NatA) complex. The auxiliary subunit of the NatA complex, NAA15, is the dimeric binding partner for NAA10. Through a genotype-first approach with whole-exome or genome sequencing (WES/WGS) and targeted sequencing analysis, we identified and phenotypically characterized 38 individuals from 33 unrelated families with 25 different de novo or inherited, dominantly acting likely gene disrupting (LGD) variants in NAA15. Clinical features of affected individuals with LGD variants in NAA15 include variable levels of intellectual disability, delayed speech and motor milestones, and autism spectrum disorder. Additionally, mild craniofacial dysmorphology, congenital cardiac anomalies, and seizures are present in some subjects. RNA analysis in cell lines from two individuals showed degradation of the transcripts with LGD variants, probably as a result of nonsense-mediated decay. Functional assays in yeast confirmed a deleterious effect for two of the LGD variants in NAA15. Further supporting a mechanism of haploinsufficiency, individuals with copy-number variant (CNV) deletions involving NAA15 and surrounding genes can present with mild intellectual disability, mild dysmorphic features, motor delays, and decreased growth. We propose that defects in NatA-mediated N-terminal acetylation (NTA) lead to variable levels of neurodevelopmental disorders in humans, supporting the importance of the NatA complex in normal human development. Copyright © 2018 American Society of Human Genetics. All rights reserved.

78 FR 76382 - Notice of Cancellation of Environmental Impact Statement for the Norfolk International Airport...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-17

... Norfolk Airport Authority (NAA), the owner and operator of the airport. The additional planning effort by NAA has modified the project purpose and need and refined various project elements, including the need... decision to prepare a federal EIS primarily on NAA's proposal to construct a new Runway 5R/23L in parallel...

Fine tuning of transmission features in nanoporous anodic alumina distributed Bragg reflectors

NASA Astrophysics Data System (ADS)

Lim, Siew Yee; Law, Cheryl Suwen; Santos, Abel

2018-01-01

This study introduces an innovative apodisation strategy to tune the filtering features of distributed Bragg reflectors based on nanoporous anodic alumina (NAA-DBRs). The effective medium of NAA-DBRs, which is modulated in a stepwise fashion by a pulse-like anodisation approach, is apodised following a logarithmic negative function to engineer the transmission features of NAA-DBRs. We investigate the effect of various apodisation parameters such as apodisation amplitude difference, anodisation period, current density offset and pore widening time, to tune and optimise the optical properties of NAA-DBRs in terms of central wavelength position, full width at half maximum and quality of photonic stop band. The transmission features of NAA-DBRs are shown to be fully controllable with precision across the spectral regions by means of the apodisation parameters. Our study demonstrates that an apodisation strategy can significantly narrow the width and enhance the quality of the characteristic photonic stop band of NAA-DBRs. This rationally designed anodisation approach based on the combination of apodisation and stepwise pulse anodisation enables the development of optical filters with tuneable filtering features to be integrated into optical technologies acting as essential photonic elements in devices such as optical sensors and biosensors.

The predictive value of baseline NAA/Cr for treatment response of first-episode schizophrenia: A ¹H MRS study.

PubMed

Liu, Weibo; Yu, Hualiang; Jiang, Biao; Pan, Bing; Yu, Shaohua; Li, Huichun; Zheng, Leilei

2015-07-23

The study focused on the predictive value of baseline metabolite ratios in bilateral hippocampus of first-episode schizophrenia by using proton magnetic resonance spectroscopy ((1)H MRS). (1)H MRS data were acquired from 23 hallucination and 17 non-hallucination first-episode schizophrenia patients compared with 17 healthy participants. Clinical characteristics of patients were rated using the Positive and Negative Syndrome Scale (PANSS) before and after 3-month treatment. The schizophrenia patients showed lower NAA/Cr ratio than healthy participants respectively (p=0.024; p=0.001), and non-hallucination patients had even lower NAA/Cr ratio than hallucination patients (p=0.033). After 3-month treatment, hallucination patients had greater improvement in negative symptoms than non-hallucination patients (p=0.018). The reduction of PANSS total score and negative factor score was positively correlated with the left NAA/Cr in both group patients (p<0.05). Given that the bilateral hippocampal baseline NAA/Cr had predictive value for the whole treatment response, and the left hippocampal NAA/Cr can predict the prognosis of negative symptoms during acute phase medication in first-episode schizophrenia. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Performance-related increases in hippocampal N-acetylaspartate (NAA) induced by spatial navigation training are restricted to BDNF Val homozygotes.

PubMed

Lövdén, Martin; Schaefer, Sabine; Noack, Hannes; Kanowski, Martin; Kaufmann, Jörn; Tempelmann, Claus; Bodammer, Nils Christian; Kühn, Simone; Heinze, Hans-Jochen; Lindenberger, Ulman; Düzel, Emrah; Bäckman, Lars

2011-06-01

Recent evidence indicates experience-dependent brain volume changes in humans, but the functional and histological nature of such changes is unknown. Here, we report that adult men performing a cognitively demanding spatial navigation task every other day over 4 months display increases in hippocampal N-acetylaspartate (NAA) as measured with magnetic resonance spectroscopy. Unlike measures of brain volume, changes in NAA are sensitive to metabolic and functional aspects of neural and glia tissue and unlikely to reflect changes in microvasculature. Training-induced changes in NAA were, however, absent in carriers of the Met substitution in the brain-derived neurotrophic factor (BDNF) gene, which is known to reduce activity-dependent secretion of BDNF. Among BDNF Val homozygotes, increases in NAA were strongly related to the degree of practice-related improvement in navigation performance and normalized to pretraining levels 4 months after the last training session. We conclude that changes in demands on spatial navigation can alter hippocampal NAA concentrations, confirming epidemiological studies suggesting that mental experience may have direct effects on neural integrity and cognitive performance. BDNF genotype moderates these plastic changes, in line with the contention that gene-context interactions shape the ontogeny of complex phenotypes.

Molecular gated nanoporous anodic alumina for the detection of cocaine

NASA Astrophysics Data System (ADS)

Ribes, Àngela; Xifré-Pérez, Elisabet; Aznar, Elena; Sancenón, Félix; Pardo, Teresa; Marsal, Lluís F.; Martínez-Máñez, Ramόn

2016-12-01

We present herein the use of nanoporous anodic alumina (NAA) as a suitable support to implement “molecular gates” for sensing applications. In our design, a NAA support is loaded with a fluorescent reporter (rhodamine B) and functionalized with a short single-stranded DNA. Then pores are blocked by the subsequent hybridisation of a specific cocaine aptamer. The response of the gated material was studied in aqueous solution. In a typical experiment, the support was immersed in hybridisation buffer solution in the absence or presence of cocaine. At certain times, the release of rhodamine B from pore voids was measured by fluorescence spectroscopy. The capped NAA support showed poor cargo delivery, but presence of cocaine in the solution selectively induced rhodamine B release. By this simple procedure a limit of detection as low as 5 × 10-7 M was calculated for cocaine. The gated NAA was successfully applied to detect cocaine in saliva samples and the possible re-use of the nanostructures was assessed. Based on these results, we believe that NAA could be a suitable support to prepare optical gated probes with a synergic combination of the favourable features of selected gated sensing systems and NAA.

Turkish adaptation and psychometric characteristics of the Nursing Authority and Autonomy Scale.

PubMed

Basaran Acil, Seher; Dinç, Leyla

2018-04-14

To adapt the Nursing Authority and Autonomy Scale (NAAS) into Turkish the Nursing Authority and Autonomy Scale (NAAS) to Turkish and assess its psychometric properties for Turkish nurses and nurse managers. The NAAS is a tool that specifically measures nursing authority and autonomy from the perspectives of nurses and nurse managers. The study sample consisted of 160 nurse managers and 266 staff nurses. Content validity was assessed using expert approval. Construct validity was assessed using confirmatory factor analysis. Internal consistency was assessed using Cronbach's α, and the test-retest reliability was assessed using Pearson's correlation coefficients. The model achieved a good fit. The internal reliability of the NAAS' authority and autonomy in nursing practice and importance of nursing practice subscales were .84. The Cronbach's α of the instrument was .88. The test-retest scores within an interval of 3 weeks were statistically not significant. The Turkish version of the NAAS has good psychometric properties and this scale can be employed to measure nurses' authority and autonomy. Nurse managers and educators should use an appropriate scale such as NAAS in order to assess nurses' clinical authority and autonomy to improve patient outcomes and develop nurses. © 2018 John Wiley & Sons Ltd.

Molecular gated nanoporous anodic alumina for the detection of cocaine.

PubMed

Ribes, Àngela; Xifré-Pérez, Elisabet; Aznar, Elena; Sancenón, Félix; Pardo, Teresa; Marsal, Lluís F; Martínez-Máñez, Ramόn

2016-12-07

We present herein the use of nanoporous anodic alumina (NAA) as a suitable support to implement "molecular gates" for sensing applications. In our design, a NAA support is loaded with a fluorescent reporter (rhodamine B) and functionalized with a short single-stranded DNA. Then pores are blocked by the subsequent hybridisation of a specific cocaine aptamer. The response of the gated material was studied in aqueous solution. In a typical experiment, the support was immersed in hybridisation buffer solution in the absence or presence of cocaine. At certain times, the release of rhodamine B from pore voids was measured by fluorescence spectroscopy. The capped NAA support showed poor cargo delivery, but presence of cocaine in the solution selectively induced rhodamine B release. By this simple procedure a limit of detection as low as 5 × 10 -7  M was calculated for cocaine. The gated NAA was successfully applied to detect cocaine in saliva samples and the possible re-use of the nanostructures was assessed. Based on these results, we believe that NAA could be a suitable support to prepare optical gated probes with a synergic combination of the favourable features of selected gated sensing systems and NAA.

Molecular gated nanoporous anodic alumina for the detection of cocaine

PubMed Central

Ribes, Àngela; Xifré -Pérez, Elisabet; Aznar, Elena; Sancenón, Félix; Pardo, Teresa; Marsal, Lluís F.; Martínez-Máñez, Ramόn

2016-01-01

We present herein the use of nanoporous anodic alumina (NAA) as a suitable support to implement “molecular gates” for sensing applications. In our design, a NAA support is loaded with a fluorescent reporter (rhodamine B) and functionalized with a short single-stranded DNA. Then pores are blocked by the subsequent hybridisation of a specific cocaine aptamer. The response of the gated material was studied in aqueous solution. In a typical experiment, the support was immersed in hybridisation buffer solution in the absence or presence of cocaine. At certain times, the release of rhodamine B from pore voids was measured by fluorescence spectroscopy. The capped NAA support showed poor cargo delivery, but presence of cocaine in the solution selectively induced rhodamine B release. By this simple procedure a limit of detection as low as 5 × 10−7 M was calculated for cocaine. The gated NAA was successfully applied to detect cocaine in saliva samples and the possible re-use of the nanostructures was assessed. Based on these results, we believe that NAA could be a suitable support to prepare optical gated probes with a synergic combination of the favourable features of selected gated sensing systems and NAA. PMID:27924950

Thousand Year Archives of the Bulk and Compound-Specific δ15N of Export Production From the North Pacific Subtropical Gyre Indicate Increasing Nitrogen Fixation Over the Past 150 Years

NASA Astrophysics Data System (ADS)

Sherwood, O.; Batista, F. C.; Brown, J. T.; Guilderson, T. P.; McCarthy, M.

2012-12-01

Stable nitrogen isotopic analysis of amino acids (δ15N-AA) preserved in proteins has emerged as a powerful new tool to explore trophic levels and nutrient cycling in nature. To date, little has been done to explore δ15N-AA in paleo-studies of the marine nitrogen cycle. We analysed the bulk and AA-specific δ15N in the long-lived, deep-sea, proteinaceous coral Gerardia. By feeding on sinking particulate organic matter, proteinaceous corals integrate the biogeochemical signature of recently exported production within discrete skeletal growth layers. Sub-decadal resolution time-series records spanning the time period 1000 AD to present were generated from specimens of Gerardia collected from the main Hawaiian Islands, Cross Seamount, and French Frigate Shoals in the North Pacific Subtropical Gyre (NPSG). Records of bulk δ15N from the three different locations, geographically separated by up to 1000 km, showed remarkably similar long term trends. Bulk δ15N remained relatively stable from ~1000-1850 years AD, and then decreased by a total of 2 ‰ from ~1850 AD to the present. The δ15N-AA of the "trophic" group of amino acids indicated no significant changes in trophic level or microbial re-synthesis of export production over this time period. The δ15N of "source" amino acids was significantly correlated with corresponding values of bulk δ15N, with the δ15N of phenylalanine decreasing from 4.2 to 2.1‰. The latter value is similar to recent measurements of subsurface nitrate δ15N near Hawaii, suggesting that the δ15N of phenylalanine may be used to quantitatively track changes in the isotopic signature of nitrate at the base of the food web. Using a simple isotopic mass balance between upwelled nitrate and nitrogen fixation we calculate a 30% increase in nitrogen fixation in the NPSG since ~1850. These results provide invaluable long-term context for recent observations, and highlight profound changes in the marine biogeochemical cycling of nitrogen over the past 150 years in this climatically-sensitive area of the world ocean.

Auxin modulates the enhanced development of root hairs in Arabidopsis thaliana (L.) Heynh. under elevated CO(2).

PubMed

Niu, Yaofang; Jin, Chongwei; Jin, Gulei; Zhou, Qingyan; Lin, Xianyong; Tang, Caixian; Zhang, Yongsong

2011-08-01

Root hairs may play a critical role in nutrient acquisition of plants grown under elevated CO(2) . This study investigated how elevated CO(2) enhanced the development of root hairs in Arabidopsis thaliana (L.) Heynh. The plants under elevated CO(2) (800 µL L(-1)) had denser and longer root hairs, and more H-positioned cells in root epidermis than those under ambient CO(2) (350 µL L(-1)). The elevated CO(2) increased auxin production in roots. Under elevated CO(2) , application of either 1-naphthoxyacetic acid (1-NOA) or N-1-naphthylphthalamic acid (NPA) blocked the enhanced development of root hairs. The opposite was true when the plants under ambient CO(2) were treated with 1-naphthylacetic acid (NAA), an auxin analogue. Furthermore, the elevated CO(2) did not enhance the development of root hairs in auxin-response mutants, axr1-3, and auxin-transporter mutants, axr4-1, aux1-7 and pin1-1. Both elevated CO(2) and NAA application increased expressions of caprice, triptychon and rho-related protein from plants 2, and decreased expressions of werewolf, GLABRA2, GLABRA3 and the transparent testa glabra 1, genes related to root-hair development, while 1-NOA and NPA application had an opposite effect. Our study suggests that elevated CO(2) enhanced the development of root hairs in Arabidopsis via the well-characterized auxin signalling and transport that modulate the initiation of root hairs and the expression of its specific genes. © 2011 Blackwell Publishing Ltd.

APOLLO CREW (NAA) - ASTRONAUT EDWARD H. WHITE - TRAINING

NASA Image and Video Library

1966-06-24

The members of the prime crew of the first manned Apollo space flight Apollo/Saturn 204 (AS-204) inspect spacecraft equipment during a tour of North American Aviation's (NAA) Downey facility. In the foreground, left to right, are astronauts Roger B. Chaffee, Virgil I. Grissom, and Edward H. White, II. NAA engineers and technicians are in the background. NORTH AMERICAN AVIATION, INC., DOWNEY, CA B&W

NAA For Human Serum Analysis: Comparison With Conventional Analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oliveira, Laura C.; Zamboni, Cibele B.; Medeiros, Jose A. G.

2010-08-04

Instrumental and Comparator methods of Neutron Activation Analysis (NAA) were applied to determine elements of clinical relevancy in serum samples of adult population (Sao Paulo city, Brazil). A comparison with the conventional analyses, Colorimetric for calcium, Titrymetric for chlorine and Ion Specific Electrode for sodium and potassium determination were also performed permitting a discussion about the performance of NAA methods for clinical chemistry research.

Effect of occupational manganese exposure on the central nervous system of welders: 1H magnetic resonance spectroscopy and MRI findings.

PubMed

Kim, Eun A; Cheong, Hae-Kwan; Choi, Dae Seob; Sakong, Joon; Ryoo, Jae Wook; Park, Injeong; Kang, Dong Mug

2007-03-01

This study investigated the relationship between long-term occupational manganese (Mn) exposure on the regional Mn concentration in the brain, neuronal loss, and neurobehavioral effects on welders. 1H MRS of the basal ganglia (BG) was performed on 20 male welders and 10 age- and gender-matched, non-office, control workers in a shipyard to assess the metabolic change, and the N-acetylaspartate (NAA)/creatine (Cr), choline (Cho)/Cr and NAA/Cho ratios, by the level of Mn exposure. We also assessed the signal intensity of T1-weighted image of magnetic resonance imaging (MRI) on globus pallidus (GP) compared to that of the frontal white matter (pallidal index, PI). The welders had significantly higher signal intensity than the controls. PI showed a significant dose-response relationship with cumulative exposure index (CEI) (r=0.54, p=0.002). CEI and PI showed different relationships with NAA/Cr according to smoking status, and the correlation was evident only in non-smokers (r=-0.73 and -0.57, respectively). There were no significant differences between the welders and the controls in NAA/Cr, Cho/Cr, and NAA/Cho ratios obtained from BG. CEI was positively correlated with simple reaction time. PI was positively correlated with mean sway (MSWAY), sway area (SWAYA), and sway intensity (SWAYI), and negatively correlated with maximum frequency (MAXF). After categorizing the subjects into two groups according to NAA/Cr ratio level, the low NAA/Cr ratio group showed significantly lower score on digit span backward and significantly higher score on MSWAY, SWAYA and SWAYI in regression analysis than the high NAA/Cr ratio group. We speculated that the NAA/Cr ratio of MRS in BG seems to reflect the cumulative effect of Mn exposure on the human brain. Due to uneven distribution of smoking among the welders and the controls, in addition to the small number of subjects in our study, our findings are needed further studies with a larger number of subjects.

Canavan disease. Analysis of the nature of the metabolic lesions responsible for development of the observed clinical symptoms.

PubMed

Baslow, M H; Resnik, T R

1997-10-01

Canavan disease (CD), a rare recessive autosomal genetic disorder, is characterized by early onset and a progressive spongy degeneration of the brain involving loss of the axon's myelin sheath. After a relatively normal birth, homozygous individuals generally develop clinical symptoms within months, and usually die within several years of the onset of the disease. A biochemical defect associated with this disease results in reduced activity of the enzyme N-acetyl-L-aspartate amidohydrolase (aspartoacylase) and affected individuals have less ability to hydrolyze N-acetyl-L-asparate (NAA) in brain and other tissues. As a result of aspartoacylase deficiency, NAA builds up in extracellular fluids (ECF) and is excreted in urine. From an analysis of the NAA biochemical cycle in various tissues of many vertebrate species, evidence is presented that there may be two distinct NAA circulation patterns related to aspartoacylase activity. These include near-field circulations in the brain and the eye, and a far-field systemic circulation involving the liver and kidney, the purpose of which in each case is apparently to regenerate aspartate (Asp) in order for it to be recycled into NAA as part of the still unknown function of the NAA cycle. Based on the authors' analysis, they have also identified several metabolic outcomes of the genetic biochemical aspartoacylase lesion. First, there is a daily induced Asp deficit in the central nervous system (CNS) that is at least six times the static level of available free Asp. Second, there is up to a 50-fold drop in the intercompartmental NAA gradient, and third, the ability of the brain to perform its normal intercompartmental cycling of NAA to Asp is terminated, and as a result, the only remaining long-term source of Asp for NAA synthesis is via nutritional supplementation of Asp or its metabolic precursors. Finally, the authors identify a potential maternal-fetal interaction that may be responsible for observed normal fetal development in utero, and that provides a rationale for, and suggests how, CD might respond to far-field nutritional, transplantation, or genetic engineering techniques to alter the course of the disease.

Piper nigrum: micropropagation, antioxidative enzyme activities, and chromatographic fingerprint analysis for quality control.

PubMed

Ahmad, Nisar; Abbasi, Bilal Haider; Rahman, Inayat ur; Fazal, Hina

2013-04-01

A reliable in vitro regeneration system for the economical and medicinally important Piper nigrum L. has been established. Callus and shoot regeneration was encouraged from leaf portions on Murashige and Skoog (MS) medium augmented with varied concentrations of plant growth regulators. A higher callus production (90 %) was observed in explants incubated on MS medium incorporated with 1.0 mg L(-1) 6-benzyladenine (BA) along with 0.5 mg L(-1) gibberellic acid after 4 weeks of culture. Moreover, a callogenic response of 85 % was also recorded for 1.0 mg L(-1) BA in combination with 0.25 mg L(-1) α-naphthalene acetic acid (NAA) and 0.25 mg L(-1) 2,4-dichlorophenoxyacetic acid or 0.5 mg L(-1) indole butyric acid (IBA) along with 0.25 mg L(-1) NAA and indole acetic acid. Subsequent sub-culturing of callus after 4 weeks of culture onto MS medium supplemented with 1.5 mg L(-1) thiodiazoran or 1.5 mg L(-1) IBA induced 100 % shoot response. Rooted plantlets were achieved on medium containing varied concentrations of auxins. The antioxidative enzyme activities [superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX)] revealed that significantly higher SOD was observed in regenerated plantlets than in other tissues. However, POD, CAT, and APX were higher in callus than in other tissues. A high-performance liquid chromatography (HPLC) fingerprint analysis protocol was established for quality control in different in vitro-regenerated tissues of P. nigrum L. During analysis, most of the common peaks represent the active principle "piperine." The chemical contents, especially piperine, showed variation from callus culture to whole plantlet regeneration. Based on the deviation in chromatographic peaks, the in vitro-regenerated plantlets exhibit a nearly similar piperine profile to acclimated plantlets. The in vitro regeneration system and HPLC fingerprint analysis established here brought a novel approach to the quality control of in vitro plantlets, producing metabolites of interest with substantial applications for the conservation of germplasm.

Direct organogenesis of Mandevilla illustris (Vell) Woodson and effects of its aqueous extract on the enzymatic and toxic activities of Crotalus durissus terrificus snake venom.

PubMed

Biondo, R; Soares, A M; Bertoni, B W; França, S C; Pereira, A M S

2004-03-01

In order to produce explants of Mandevilla illustris (Vell) Woodson for the "Cerrado in vitro", the Germplasm Bank of UNAERP, we carried out a micropropagation protocol using MS or MS/3 medium supplemented with different concentrations of 6-benzyladeninepurine (BA), Zeatin or 2-isopentenyladenine for nodal segment growth, and alpha-naphthaleneacetic acid, indole-3-butyric acid (IBA) or 1,4 dithiothreitol for rooting. For nodal segments, all the cytokinins tested yielded similar results. However, 2.22 micro M BA is more economical to use. MS/3 medium supplemented with 0.49 micro M IBA was the most appropriate medium for rooting, resulting in 29% rooted explants. The crude aqueous extract from the subterranean system (SS) of M. illustris was assayed for its inhibitory action on the enzymatic activity of Crotalus durissus terrificus snake venom, isolated basic phospholipase A2 (CB) and crotoxin. It totally inhibited the phospholipase activity of crude Cdt venom and CB toxin and inhibited the phospholipase activity of crotoxin by 49%. The toxic action of both the crude venom and crotoxin was partially inhibited-there was a prolonged survival time and a 40.0% decrease in lethality.

A document review to characterize Atomic International SNAP fuels shipped to INEL 1966--1973

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wahnschaffe, S.D.; Lords, R.E.; Kneff, D.W.

1995-09-01

This report provides the results of a document search and review study to obtain information on the spent fuels for the following six Nuclear Auxiliary Power (SNAP) reactor cores now stored at the Idaho National Engineering Laboratory (INEL): SNAP-2 Experimental Reactor, SNAP-2 Development Reactor, SNAP-10A Ground Test Reactor, SNAP-8 Experimental Reactor, SNAP-8 Development Reactor, and Shield Test Reactor. The report also covers documentation on SNAP fuel materials from four in-pile materials tests: NAA-82-1, NAA-115-2, NAA-117-1, and NAA-121. Pieces of these fuel materials are also stored at INEL as part of the SNAP fuel shipments.

Realisation and advanced engineering of true optical rugate filters based on nanoporous anodic alumina by sinusoidal pulse anodisation

NASA Astrophysics Data System (ADS)

Santos, Abel; Yoo, Jeong Ha; Rohatgi, Charu Vashisth; Kumeria, Tushar; Wang, Ye; Losic, Dusan

2016-01-01

This study is the first realisation of true optical rugate filters (RFs) based on nanoporous anodic alumina (NAA) by sinusoidal waves. An innovative and rationally designed sinusoidal pulse anodisation (SPA) approach in galvanostatic mode is used with the aim of engineering the effective medium of NAA in a sinusoidal fashion. A precise control over the different anodisation parameters (i.e. anodisation period, anodisation amplitude, anodisation offset, number of pulses, anodisation temperature and pore widening time) makes it possible to engineer the characteristic reflection peaks and interferometric colours of NAA-RFs, which can be finely tuned across the UV-visible-NIR spectrum. The effect of the aforementioned anodisation parameters on the photonic properties of NAA-RFs (i.e. characteristic reflection peaks and interferometric colours) is systematically assessed in order to establish for the first time a comprehensive rationale towards NAA-RFs with fully controllable photonic properties. The experimental results are correlated with a theoretical model (Looyenga-Landau-Lifshitz - LLL), demonstrating that the effective medium of these photonic nanostructures can be precisely described by the effective medium approximation. NAA-RFs are also demonstrated as chemically selective photonic platforms combined with reflectometric interference spectroscopy (RIfS). The resulting optical sensing system is used to assess the reversible binding affinity between a model drug (i.e. indomethacin) and human serum albumin (HSA) in real-time. Our results demonstrate that this system can be used to determine the overall pharmacokinetic profile of drugs, which is a critical aspect to be considered for the implementation of efficient medical therapies.This study is the first realisation of true optical rugate filters (RFs) based on nanoporous anodic alumina (NAA) by sinusoidal waves. An innovative and rationally designed sinusoidal pulse anodisation (SPA) approach in galvanostatic mode is used with the aim of engineering the effective medium of NAA in a sinusoidal fashion. A precise control over the different anodisation parameters (i.e. anodisation period, anodisation amplitude, anodisation offset, number of pulses, anodisation temperature and pore widening time) makes it possible to engineer the characteristic reflection peaks and interferometric colours of NAA-RFs, which can be finely tuned across the UV-visible-NIR spectrum. The effect of the aforementioned anodisation parameters on the photonic properties of NAA-RFs (i.e. characteristic reflection peaks and interferometric colours) is systematically assessed in order to establish for the first time a comprehensive rationale towards NAA-RFs with fully controllable photonic properties. The experimental results are correlated with a theoretical model (Looyenga-Landau-Lifshitz - LLL), demonstrating that the effective medium of these photonic nanostructures can be precisely described by the effective medium approximation. NAA-RFs are also demonstrated as chemically selective photonic platforms combined with reflectometric interference spectroscopy (RIfS). The resulting optical sensing system is used to assess the reversible binding affinity between a model drug (i.e. indomethacin) and human serum albumin (HSA) in real-time. Our results demonstrate that this system can be used to determine the overall pharmacokinetic profile of drugs, which is a critical aspect to be considered for the implementation of efficient medical therapies. Electronic supplementary information (ESI) available: Table containing a comprehensive summary of the effect of the different anodisation parameters on the characteristic reflection peaks of NAA-RFs and further information on the relationship between glucose concentration and its refractive index and examples of ΔλPeak calculation for establishing the binding affinity between HSA and indomethacin molecules. See DOI: 10.1039/c5nr05462a

Spectroscopic imaging of the pilocarpine model of human epilepsy suggests that early NAA reduction predicts epilepsy.

PubMed

Gomes, W A; Lado, F A; de Lanerolle, N C; Takahashi, K; Pan, C; Hetherington, H P

2007-08-01

Reduced hippocampal N-acetyl aspartate (NAA) is commonly observed in patients with advanced, chronic temporal lobe epilepsy (TLE). It is unclear, however, whether an NAA deficit is also present during the clinically quiescent latent period that characterizes early TLE. This question has important implications for the use of MR spectroscopic imaging (MRSI) in the early identification of patients at risk for TLE. To determine whether NAA is diminished during the latent period, we obtained high-resolution (1)H spectroscopic imaging during the latent period of the rat pilocarpine model of human TLE. We used actively detuneable surface reception and volume transmission coils to enhance sensitivity and a semiautomated voxel shifting method to accurately position voxels within the hippocampi. During the latent period, 2 and 7 d following pilocarpine treatment, hippocampal NAA was significantly reduced by 27.5 +/- 6.9% (P < 0.001) and 17.3 +/- 6.9% (P < 0.001) at 2 and 7 d, respectively. Quantitative estimates of neuronal loss at 7 d (2.3 +/- 7.7% reduction; P = 0.58, not significant) demonstrate that the NAA deficit is not due to neuron loss and therefore likely represents metabolic impairment of hippocampal neurons during the latent phase. Therefore, spectroscopic imaging provides an early marker for metabolic dysfunction in this model of TLE.

Rational Design of Photonic Dust from Nanoporous Anodic Alumina Films: A Versatile Photonic Nanotool for Visual Sensing

PubMed Central

Chen, Yuting; Santos, Abel; Wang, Ye; Kumeria, Tushar; Ho, Daena; Li, Junsheng; Wang, Changhai; Losic, Dusan

2015-01-01

Herein, we present a systematic study on the development, optimisation and applicability of interferometrically coloured distributed Bragg reflectors based on nanoporous anodic alumina (NAA-DBRs) in the form of films and nanoporous microparticles as visual/colorimetric analytical tools. Firstly, we synthesise a complete palette of NAA-DBRs by galvanostatic pulse anodisation approach, in which the current density is altered in a periodic fashion in order to engineer the effective medium of the resulting photonic films in depth. NAA-DBR photonic films feature vivid colours that can be tuned across the UV-visible-NIR spectrum by structural engineering. Secondly, the effective medium of the resulting photonic films is assessed systematically by visual analysis and reflectometric interference spectroscopy (RIfS) in order to establish the most optimal nanoporous platforms to develop visual/colorimetric tools. Then, we demonstrate the applicability of NAA-DBR photonic films as a chemically selective sensing platform for visual detection of mercury(II) ions. Finally, we generate a new nanomaterial, so-called photonic dust, by breaking down NAA-DBRs films into nanoporous microparticles. The resulting microparticles (μP-NAA-DBRs) display vivid colours and are sensitive towards changes in their effective medium, opening new opportunities for developing advanced photonic nanotools for a broad range of applications. PMID:26245759

Rational Design of Photonic Dust from Nanoporous Anodic Alumina Films: A Versatile Photonic Nanotool for Visual Sensing

NASA Astrophysics Data System (ADS)

Chen, Yuting; Santos, Abel; Wang, Ye; Kumeria, Tushar; Ho, Daena; Li, Junsheng; Wang, Changhai; Losic, Dusan

2015-08-01

Herein, we present a systematic study on the development, optimisation and applicability of interferometrically coloured distributed Bragg reflectors based on nanoporous anodic alumina (NAA-DBRs) in the form of films and nanoporous microparticles as visual/colorimetric analytical tools. Firstly, we synthesise a complete palette of NAA-DBRs by galvanostatic pulse anodisation approach, in which the current density is altered in a periodic fashion in order to engineer the effective medium of the resulting photonic films in depth. NAA-DBR photonic films feature vivid colours that can be tuned across the UV-visible-NIR spectrum by structural engineering. Secondly, the effective medium of the resulting photonic films is assessed systematically by visual analysis and reflectometric interference spectroscopy (RIfS) in order to establish the most optimal nanoporous platforms to develop visual/colorimetric tools. Then, we demonstrate the applicability of NAA-DBR photonic films as a chemically selective sensing platform for visual detection of mercury(II) ions. Finally, we generate a new nanomaterial, so-called photonic dust, by breaking down NAA-DBRs films into nanoporous microparticles. The resulting microparticles (μP-NAA-DBRs) display vivid colours and are sensitive towards changes in their effective medium, opening new opportunities for developing advanced photonic nanotools for a broad range of applications.

Neurochemistry in shiverer mouse depicted on MR spectroscopy.

PubMed

Takanashi, Jun-ichi; Nitta, Nobuhiro; Iwasaki, Nobuaki; Saito, Shigeyoshi; Tanaka, Ryuta; Barkovich, A James; Aoki, Ichio

2014-06-01

To evaluate the neurochemical changes associated with hypomyelination, especially to clarify whether increased total N-acetylaspartate (tNAA) with decreased choline (Cho) observed in the thalamus of msd mice with the plp1 mutation is a common finding for hypomyelinating disorders. We performed magnetic resonance imaging (MRI) and proton MR spectroscopy ((1) H-MRS) of the thalamus and cortex of postnatal 12-week shiverer mice devoid of myelin basic protein (mbp), heterozygous and wild-type mice with a 7.0T magnet. Luxol Fast Blue staining and immunohistochemical analysis with anti-Mbp, Gfap, Olig2, and NeuN antibodies were also performed. In the thalamus, decreased Cho and normal tNAA were observed in shiverer mice. In the cortex, tNAA, Cho, and glutamate were decreased in shiverer mice. Histological and immunohistochemical analysis of shiverer mice brains revealed hypomyelination in the thalamus, white matter, and cortex; astrogliosis and an increased number of total oligodendrocytes in the white matter; and a decreased number of neurons in the cortex. The reduction of Cho on (1) H-MRS might be a common marker for hypomyelinating disorders. A normal tNAA level in the thalamus of shiverer mice might be explained by the presence of mature oligodendrocytes, which enable neuron-to-oligodendrocyte NAA transport or NAA catabolism. Copyright © 2013 Wiley Periodicals, Inc.

Regional metabolic changes in the hippocampus and posterior cingulate area detected with 3-Tesla magnetic resonance spectroscopy in patients with mild cognitive impairment and Alzheimer disease.

PubMed

Wang, Zhiqun; Zhao, Cheng; Yu, Lei; Zhou, Weidong; Li, Kuncheng

2009-04-01

Magnetic resonance spectroscopy (MRS) plays an important role in early diagnosis of Alzheimer disease (AD). There are many reports on MRS studies among individuals with AD and mild cognitive impairment (MCI). However, very few studies have compared spectroscopic data of different limbic regions among AD and MCI subjects. To compare metabolite changes of different regions in the brain of AD and MCI patients by using 3.0 T short-echo-time MRS. Metabolite ratios in the hippocampus and posterior cingulate area were compared in a group of patients with AD (n=16), MCI (n=16), and normal subjects as a control group (n=16). Clinical neuropsychological tests were measured in all subjects. In the hippocampus, there were significant differences in N-acetylaspartate (NAA)/creatine (Cr), myo-inositol (mI)/Cr, and mI/NAA ratios among the three groups. However, there were no significant differences in choline (Cho)/Cr ratio among the three groups. In the posterior cingulate area, there were no significant differences in the NAA/Cr, Cho/Cr, and mI/Cr ratios among the three groups. However, there were significant differences in mI/NAA ratio between patients with AD and the control group, and between the AD and MCI groups. In addition, there was significant correlation between mI/NAA ratio and Mini Mental Status Exam (MMSE) score in subjects with AD and MCI. The study reveals that the elevation of mI/NAA ratio in the hippocampus is more significant than that in the posterior cingulate area, which corresponds to the pathologic procession of AD. The ratios of mI/NAA in the hippocampus and in the posterior cingulate area together provide valuable discrimination among the three groups (AD, MCI, and controls). There is a significant correlation between mI/NAA ratio and cognitive decline.

The positive effects of high-frequency right dorsolateral prefrontal cortex repetitive transcranial magnetic stimulation on memory, correlated with increases in brain metabolites detected by proton magnetic resonance spectroscopy in recently detoxified alcohol-dependent patients.

PubMed

Qiao, Jun; Jin, Guixing; Lei, Licun; Wang, Lan; Du, Yaqiang; Wang, Xueyi

2016-01-01

To explore the effect of right dorsolateral prefrontal cortex (DLPFC) repetitive transcranial magnetic stimulation (rTMS) on memory, and its correlation with levels of hippocampal brain metabolites detected by proton magnetic resonance spectroscopy ( 1 H-MRS) in recently detoxified alcohol-dependent patients. In this randomized, double-blind sham-controlled trial, alcohol-dependent patients were enrolled and randomized into two groups: the experimental group (rTMS, 10 Hz, on right DLPFC, 20 sessions) and the control group (sham stimulation). Memory function was assessed using Hopkins Verbal Learning Test-Revised (HVLT-R) and Brief Visuospatial Memory Test-Revised (BVMT-R) before and after treatment. 1 H-MRS was used to detect the levels of N -acetyl aspartic acid (NAA), choline (Cho), and creatine (Cr) in bilateral hippocampi before and after treatment. Thirty-eight patients (18 in the experimental group and 20 in the control group) were included in the analyses. The experimental group showed significantly greater changes in HVLT-R, BVMT-R, NAA/Cr, and Cho/Cr after rTMS from baseline than the control group. The percentage change in BVMT-R and HVLT-R correlated with the percentage change in NAA/Cr and Cho/Cr in the right brain. High-frequency right DLPFC rTMS was associated with improvement in memory dysfunction, which is correlated with levels of hippocampal brain metabolites detected by 1 H-MRS in recently detoxified alcohol-dependent patients.

Leaf expansion in Phaseolus: transient auxin-induced growth increase

PubMed Central

Keller, Christopher P.

2017-01-01

Control of leaf expansion by auxin is not well understood. Evidence from short term exogenous applications and from treatment of excised tissues suggests auxin positively influences growth. Manipulations of endogenous leaf auxin content, however, suggests that, long-term, auxin suppresses leaf expansion. This study attempts to clarify the growth effects of auxin on unifoliate (primary) leaves of the common bean (Phaseolus vulgaris) by reexamining the response to auxin treatment of both excised leaf strips and attached leaves. Leaf strips, incubated in culture conditions that promoted steady elongation for up to 48 h, treated with 10 μM NAA responded with an initial surge of elongation growth complete within 10 hours followed by insensitivity. A range of NAA concentrations from 0.1 μM to 300 μM induced increased strip elongation after 24 hours and 48 hours. Increased elongation and epinastic curvature of leaf strips was found specific to active auxins. Expanding attached unifoliates treated once with aqueous auxin α-naphthalene acetic acid (NAA) at 1.0 mM showed both an initial surge in growth lasting 4–6 hours followed by growth inhibition sustained at least as long as 24 hours post treatment. Auxin-induced inhibition of leaf expansion was associated with smaller epidermal cell area. Together the results suggest increasing leaf auxin first increases growth then slows growth through inhibition of cell expansion. Excised leaf strips, retain only the initial increased growth response to auxin and not the subsequent growth inhibition, either as a consequence of wounding or of isolation from the plant. PMID:29200506

Green and non-green callus induction from excised rice (Oryza sativa) embryos: effects of exogenous plant growth regulators

NASA Technical Reports Server (NTRS)

Kim, D.; Brock, T. G.; Kaufman, P. B.

1992-01-01

Calli were induced either from excised rice embryos or from whole seeds in the presence of 1 to 5 mg l-1 NAA. After 12 days of culture, calli were induced only from excised rice embryos. We found that excised embryos accumulated NAA up to 6 times higher concentration than did whole seeds. In the presence of 1 to 5 mg l-1 NAA and 2 to 10 mg l-1 kinetin, chlorophyllous calli were induced from excised rice embryos. Chlorophyll contents in the callus tissue increased with increasing kinetin concentration while percent callus induction decreased. The total chlorophyll content was linearly correlated with the ratio of kinetin to NAA in the medium.

Effects of ultrasonic treatment on zeolite NaA synthesized from by-product silica.

PubMed

Vaičiukynienė, Danutė; Kantautas, Aras; Vaitkevičius, Vitoldas; Jakevičius, Leonas; Rudžionis, Žymantas; Paškevičius, Mantas

2015-11-01

The synthesis of zeolite NaA from silica by-product was carried out in the presence of 20 kHz ultrasound at room temperature. Zeolites obtained in this type of synthesis were compared to zeolites obtained by performing conventional static syntheses under similar conditions. The sonication effects on zeolite NaA synthesis were characterized by phase identification, crystallinity etc. The effects of different parameters such as crystallization time and initial materials preparation methods on the crystallinity and morphology of the synthesized zeolites were investigated. The final products were characterized by XRD and FT-IR. It was possible to obtain crystalline zeolite NaA from by-product silica in the presence of ultrasound. Copyright © 2015 Elsevier B.V. All rights reserved.

Novel Synthesis Method of Micronized Ti-Zeolite Na-A and Cytotoxic Activity of Its Silver Exchanged Form

PubMed Central

Youssef, H. F.; Hegazy, W. H.; Abo-almaged, H. H.; El-Bassyouni, G. T.

2015-01-01

The core-shell method is used as a novel synthetic process of micronized Ti-Zeolite Na-A which involves calcination at 700°C of coated Egyptian Kaolin with titanium tetrachloride in acidic medium as the first step. The produced Ti-coated metakaolinite is subjected to microwave irradiation at low temperature of 80°C for 2 h. The prepared micronized Ti-containing Zeolites-A (Ti-Z-A) is characterized by FTIR, XRF, XRD, SEM, and EDS elemental analysis. Ag-exchanged form of Ti-Z-Ag is also prepared and characterized. The Wt% of silver exchanged onto the Ti-Zeolite structure was determined by atomic absorption spectra. The in vitro cytotoxic activity of Ti-Z-Ag against human hepatocellular carcinoma cell line (HePG2), colon cell line carcinoma (HCT116), lung carcinoma cell line (A549), and human Caucasian breast adenocarcinoma (MCF7) is reported. The results were promising and revealed that the exchanged Ag form of micronized Ti-Zeolite-A can be used as novel antitumor drug. PMID:25705142

Genetic programming based models in plant tissue culture: An addendum to traditional statistical approach.

PubMed

Mridula, Meenu R; Nair, Ashalatha S; Kumar, K Satheesh

2018-02-01

In this paper, we compared the efficacy of observation based modeling approach using a genetic algorithm with the regular statistical analysis as an alternative methodology in plant research. Preliminary experimental data on in vitro rooting was taken for this study with an aim to understand the effect of charcoal and naphthalene acetic acid (NAA) on successful rooting and also to optimize the two variables for maximum result. Observation-based modelling, as well as traditional approach, could identify NAA as a critical factor in rooting of the plantlets under the experimental conditions employed. Symbolic regression analysis using the software deployed here optimised the treatments studied and was successful in identifying the complex non-linear interaction among the variables, with minimalistic preliminary data. The presence of charcoal in the culture medium has a significant impact on root generation by reducing basal callus mass formation. Such an approach is advantageous for establishing in vitro culture protocols as these models will have significant potential for saving time and expenditure in plant tissue culture laboratories, and it further reduces the need for specialised background.

An efficient in vitro regeneration protocol for a natural dye yielding plant, Strobilanthes flaccidifolious Nees., from nodal explants.

PubMed

Deb, Chitta Ranjan; Arenmongla, T

2012-11-01

Adventitious shoot buds formation from axillary buds of nodal segments of S. flaccidifolious was achieved on MS medium containing sucrose (3%, w/v), and a-naphthalene acetic acid (NAA; 3 microM) and benzyl adenine (3 microM) in combination. The nodal segments were primed on 'Growtak Sieve' for 48 h on MS medium containing sucrose (2%), polyvinyl pyrollidone (200 mgL(-1)) as antioxidant. About 80% of primed nodal segments responded positively and formed approximately 12 adventitious shoot buds per explants from explants collected during October-November months of every year. The shoot buds converted into plantlets on MS medium containing sucrose (3%) and kinetin (3 microM) where approximately 7 micro shoots developed per subculture after 8 weeks of culture. The regenerated micro shoots induced average 14 roots/plant on medium containing NAA (3 microM). The regenerates were hardened for 6-7 weeks on medium with 1/2MS salt solution and sucrose (2%) under normal laboratory condition before transferring to potting mix. About 70% transplants survived after two months of transfer.

Growth of vegetative explant Moringa oleifera on different composition of auxin and cytokinin and its synthetic seed germination

NASA Astrophysics Data System (ADS)

Muslihatin, Wirdhatul; Jadid, Nurul; Puspitasari, Ika D.; Safitri, Chusnul E.

2017-06-01

The spread of Moringa oleifera is also rare for seed germination and viability or survival are low, and the lack of vegetative propagation method. The purpose of this study are to determine the effect of auxin and cytokinin on growth vegetative explants Moringa oleifera and its synthetic seed germination. The explants grown on MS medium with sucrose content of 30% and a range of additional hormone. Addition concentration and different types of hormone made in order to know the sensitivity and response explant growth on a variety of media to get a good callus and embryosomatic. The composition of the hormone given is MS + 2.4 D 3 ppm; MS + 2,4D 2 ppm + BAP 2 ppm; MS + NAA + 0.5 ppm kinetin 1 ppm; MS + NAA 1 ppm + kinetin 1 ppm; MS + NAA 1 ppm + 0.5 ppm kinetin. The explants were incubated at a temperature of 18-20 ° C with a photoperiod 16/8. Explants and MS medium is incubated to form embryonic callus. Seeds synthetic made from embryonic callus growing on medium 1 ppm kinetin + NAA 1 ppm with encapsulation method with sodium alginate 2%. Seed synthetic germinated in some kind of medium that medium ms0 solid (M1), ms0 liquid (M2), MS0 semi-solid (M3), MS solid NAA 1ppm + Kinetin 1 ppm (M4), MS liquid NAA 1 ppm + kinetin (M5), and semi-solid MS + NAA 1 ppm kinetin 1 ppm (M6). Synthetic seed viability was observed with the parameters of the fresh weight of synthetic seed, germination percentage and seedling. Chlorophyll content was measured by spectrophotometric method with solvent asseton. Best callus generated in this study are embryonic callus that grew on media NAA 1 ppm + kinetin 1 ppm. Embryonic callus on M6 + NAA 1 ppm kinetin 1 ppm capable of germination with an average weight of callus and sprouts of 40.38 mg. Of the entire amount of a synthetic seed on M6, just 5 seed germinate, so the percentage of germination of seeds is equal to 41.67%. with an average length of sprouts 1 cm with an average total chlorophyll content of 8.66 mg / g.

Serial MR Spectroscopy Reveals a Direct Metabolic Effect of Cediranib in Glioblastoma

PubMed Central

Kim, Heisoog; Catana, Ciprian; Ratai, Eva-Maria; Andronesi, Ovidiu C.; Jennings, D.; Batchelor, Tracy T.; Jain, Rakesh K.; Sorensen, A. Gregory

2011-01-01

Proton magnetic resonance spectroscopy (1H-MRS) is increasingly used in clinical studies of brain tumor to provide information about tissue metabolic profiles. In this study, we evaluated changes in the levels of metabolites predominant in recurrent glioblastoma (rGBM), to characterize the response of rGBM to anti-angiogenic therapy. We examined thirty-one rGBM patients treated with daily doses of cediranib, acquiring serial chemical shift imaging data at specific time points during the treatment regimen. We defined spectra from three regions of interest (ROIs)—enhancing tumor (ET), peritumoral tissue (PT), and normal tissue on the contralateral side (cNT)—in post-contrast T1-weighted images, and normalized the concentrations of N-acetylaspartate (NAA) and choline (Cho) in each ROI to the concentration of creatine in cNT (norCre). We analyzed the ratios of these normalized metabolites (i.e., NAA/Cho, NAA/norCre, and Cho/norCre) by averaging all patients and categorizing two different survival groups. Relative to pre-treatment values, NAA/Cho in ET was unchanged through day 28. However, after day 28, NAA/Cho significantly increased in relation to a significant increase in NAA/norCre and a decrease in Cho/norCre; interestingly, the observed trend was reversed after day 56, consistent with the clinical course of GBM recurrence. Notably, ROC analysis indicated that NAA/Cho in tumor shows a high prediction to 6-month overall survival. These metabolic changes in these rGBM patients strongly suggest a direct metabolic effect of cediranib, and might also reflect an anti-tumor response to anti-angiogenic treatment during the first two months of treatment. Further study is needed to confirm these findings. PMID:21507932

Low thalamic NAA-concentration corresponds to strong neural activation in working memory in Kleine-Levin syndrome.

PubMed

Vigren, Patrick; Tisell, Anders; Engström, Maria; Karlsson, Thomas; Leinhard Dahlqvist, Olof; Lundberg, Peter; Landtblom, Anne-Marie

2013-01-01

Kleine Levin Syndrome (KLS) is a rare disorder of periodic hypersomnia and behavioural disturbances in young individuals. It has previously been shown to be associated with disturbances of working memory (WM), which, in turn, was associated with higher activation of the thalamus with increasing WM load, demonstrated with functional magnetic resonance imaging (fMRI). In this study we aimed to further elucidate how these findings are related to the metabolism of the thalamus. fMRI and magnetic resonance spectroscopy were applied while performing a WM task. Standard metabolites were examined: n-acetylaspartate (NAA), myo-inositol, choline, creatine and glutamate-glutamine. Fourteen KLS-patients and 15 healthy controls participated in the study. The patients with active disease were examined in asymptomatic periods. There was a statistically significant negative correlation between thalamic fMRI-activation and thalamic NAA, i.e., high fMRI-activation corresponded to low NAA-levels. This correlation was not seen in healthy controls. Thalamic levels of NAA in patients and controls showed no significant differences between the groups. None of the other metabolites showed any co-variation with fMRI-activation. This study shows negative correlation between NAA-levels and fMRI-activity in the left thalamus of KLS-patients while performing a WM task. This correlation could not be found in healthy control subjects, primarily interpreted as an effect of increased effort in the patient group upon performing the task. It might indicate a disturbance in the neuronal networks responsible for WM in KLS patients, resulting in higher effort at lower WM load, compared with healthy subjects. The general relationship between NAA and BOLD-signal is also discussed in the article.

Analysis of the posterior cingulate cortex with [18F]FDG-PET and Naa/mI in mild cognitive impairment and Alzheimer's disease: Correlations and differences between the two methods.

PubMed

Coutinho, Artur M N; Porto, Fábio H G; Zampieri, Poliana F; Otaduy, Maria C; Perroco, Tíbor R; Oliveira, Maira O; Nunes, Rafael F; Pinheiro, Toulouse Leusin; Bottino, Cassio M C; Leite, Claudia C; Buchpiguel, Carlos A

2015-01-01

Reduction of regional brain glucose metabolism (rBGM) measured by [18F]FDG-PET in the posterior cingulate cortex (PCC) has been associated with a higher conversion rate from mild cognitive impairment (MCI) to Alzheimer's disease (AD). Magnetic Resonance Spectroscopy (MRS) is a potential biomarker that has disclosed Naa/mI reductions within the PCC in both MCI and AD. Studies investigating the relationships between the two modalities are scarce. To evaluate differences and possible correlations between the findings of rBGM and NAA/mI in the PCC of individuals with AD, MCI and of cognitively normal volunteers. Patients diagnosed with AD (N=32) or MCI (N=27) and cognitively normal older adults (CG, N=28), were submitted to [18F]FDG-PET and MRS to analyze the PCC. The two methods were compared and possible correlations between the modalities were investigated. The AD group exhibited rBGM reduction in the PCC when compared to the CG but not in the MCI group. MRS revealed lower NAA/mI values in the AD group compared to the CG but not in the MCI group. A positive correlation between rBGM and NAA/mI in the PCC was found. NAA/mI reduction in the PCC differentiated AD patients from control subjects with an area under the ROC curve of 0.70, while [18F]FDG-PET yielded a value of 0.93. rBGM and Naa/mI in the PCC were positively correlated in patients with MCI and AD. [18F]FDG-PET had greater accuracy than MRS for discriminating AD patients from controls.

Analysis of the posterior cingulate cortex with [18F]FDG-PET and Naa/mI in mild cognitive impairment and Alzheimer's disease: Correlations and differences between the two methods

PubMed Central

Coutinho, Artur M.N.; Porto, Fábio H.G.; Zampieri, Poliana F.; Otaduy, Maria C.; Perroco, Tíbor R.; Oliveira, Maira O.; Nunes, Rafael F.; Pinheiro, Toulouse Leusin; Bottino, Cassio M.C.; Leite, Claudia C.; Buchpiguel, Carlos A.

2015-01-01

Reduction of regional brain glucose metabolism (rBGM) measured by [18F]FDG-PET in the posterior cingulate cortex (PCC) has been associated with a higher conversion rate from mild cognitive impairment (MCI) to Alzheimer's disease (AD). Magnetic Resonance Spectroscopy (MRS) is a potential biomarker that has disclosed Naa/mI reductions within the PCC in both MCI and AD. Studies investigating the relationships between the two modalities are scarce. Objective To evaluate differences and possible correlations between the findings of rBGM and NAA/mI in the PCC of individuals with AD, MCI and of cognitively normal volunteers. Methods Patients diagnosed with AD (N=32) or MCI (N=27) and cognitively normal older adults (CG, N=28), were submitted to [18F]FDG-PET and MRS to analyze the PCC. The two methods were compared and possible correlations between the modalities were investigated. Results The AD group exhibited rBGM reduction in the PCC when compared to the CG but not in the MCI group. MRS revealed lower NAA/mI values in the AD group compared to the CG but not in the MCI group. A positive correlation between rBGM and NAA/mI in the PCC was found. NAA/mI reduction in the PCC differentiated AD patients from control subjects with an area under the ROC curve of 0.70, while [18F]FDG-PET yielded a value of 0.93. Conclusion rBGM and Naa/mI in the PCC were positively correlated in patients with MCI and AD. [18F]FDG-PET had greater accuracy than MRS for discriminating AD patients from controls. PMID:29213988

Synthesis of zeolite NaA membrane from fused fly ash extract.

PubMed

Ameh, Alechine E; Musyoka, Nicholas M; Fatoba, Ojo O; Syrtsova, Daria A; Teplyakov, Vladimir V; Petrik, Leslie F

2016-01-01

Zeolite-NaA membranes were synthesized from an extract of fused South African fly ash on a porous titanium support by a secondary growth method. The influence of the synthesis molar regime on the formation of zeolite NaA membrane layer was investigated. Two synthesis mixtures were generated by adding either aluminium hydroxide or sodium aluminate to the fused fly ash extract. The feedstock material and the synthesized membranes were characterized by X-diffraction (XRD), scanning electron microscopy (SEM) and X-ray fluorescence spectroscopy (XRF). It was found by XRD and SEM that the cubic crystals of a typical zeolite NaA with a dense intergrown layer was formed on the porous Ti support. The study shows that the source of Al used had an effect on the membrane integrity as sodium aluminate provided the appropriate amount of Na(+) to form a coherent membrane of zeolite NaA, whereas aluminium hydroxide did not. Morphological, the single hydrothermal stage seeded support formed an interlocked array of zeolite NaA particles with neighbouring crystals. Also, a robust, continuous and well-intergrown zeolite NaA membrane was formed with neighbouring crystals of zeolite fused to each other after the multiple stage synthesis. The synthesized membrane was permeable to He (6.0 × 10(6) L m(-2)h(-1) atm(-1)) and CO2 (5.6 × 10(6) L m(-2)h(-1) atm(-1)), which indicate that the layer of the membrane was firmly attached to the porous Ti support. Membrane selectivity was maintained showing membrane integrity with permselectivity of 1.1, showing that a waste feedstock, fly ash, could be utilized for preparing robust zeolite NaA membranes on Ti support.

N-acetylaspartate catabolism determines cytosolic acetyl-CoA levels and histone acetylation in brown adipocytes

PubMed Central

Prokesch, A.; Pelzmann, H. J.; Pessentheiner, A. R.; Huber, K.; Madreiter-Sokolowski, C. T.; Drougard, A.; Schittmayer, M.; Kolb, D.; Magnes, C.; Trausinger, G.; Graier, W. F.; Birner-Gruenberger, R.; Pospisilik, J. A.; Bogner-Strauss, J. G.

2016-01-01

Histone acetylation depends on the abundance of nucleo-cytoplasmic acetyl-CoA. Here, we present a novel route for cytoplasmic acetyl-CoA production in brown adipocytes. N-acetylaspartate (NAA) is a highly abundant brain metabolite catabolized by aspartoacylase yielding aspartate and acetate. The latter can be further used for acetyl-CoA production. Prior to this work, the presence of NAA has not been described in adipocytes. Here, we show that accumulation of NAA decreases the brown adipocyte phenotype. We increased intracellular NAA concentrations in brown adipocytes via media supplementation or knock-down of aspartoacylase and measured reduced lipolysis, thermogenic gene expression, and oxygen consumption. Combinations of approaches to increase intracellular NAA levels showed additive effects on lipolysis and gene repression, nearly abolishing the expression of Ucp1, Cidea, Prdm16, and Ppara. Transcriptome analyses of aspartoacylase knock-down cells indicate deficiencies in acetyl-CoA and lipid metabolism. Concordantly, cytoplasmic acetyl-CoA levels and global histone H3 acetylation were decreased. Further, activating histone marks (H3K27ac and H3K9ac) in promoters/enhancers of brown marker genes showed reduced acetylation status. Taken together, we present a novel route for cytoplasmic acetyl-CoA production in brown adipocytes. Thereby, we mechanistically connect the NAA pathway to the epigenomic regulation of gene expression, modulating the phenotype of brown adipocytes. PMID:27045997

Engineering of Surface Chemistry for Enhanced Sensitivity in Nanoporous Interferometric Sensing Platforms.

PubMed

Law, Cheryl Suwen; Sylvia, Georgina M; Nemati, Madieh; Yu, Jingxian; Losic, Dusan; Abell, Andrew D; Santos, Abel

2017-03-15

We explore new approaches to engineering the surface chemistry of interferometric sensing platforms based on nanoporous anodic alumina (NAA) and reflectometric interference spectroscopy (RIfS). Two surface engineering strategies are presented, namely (i) selective chemical functionalization of the inner surface of NAA pores with amine-terminated thiol molecules and (ii) selective chemical functionalization of the top surface of NAA with dithiol molecules. The strong molecular interaction of Au 3+ ions with thiol-containing functional molecules of alkane chain or peptide character provides a model sensing system with which to assess the sensitivity of these NAA platforms by both molecular feature and surface engineering. Changes in the effective optical thickness of the functionalized NAA photonic films (i.e., sensing principle), in response to gold ions, are monitored in real-time by RIfS. 6-Amino-1-hexanethiol (inner surface) and 1,6-hexanedithiol (top surface), the most sensitive functional molecules from approaches i and ii, respectively, were combined into a third sensing strategy whereby the NAA platforms are functionalized on both the top and inner surfaces concurrently. Engineering of the surface according to this approach resulted in an additive enhancement in sensitivity of up to 5-fold compared to previously reported systems. This study advances the rational engineering of surface chemistry for interferometric sensing on nanoporous platforms with potential applications for real-time monitoring of multiple analytes in dynamic environments.

Magnetic resonance spectroscopy findings in photosensitive idiopathic generalized epilepsy.

PubMed

Aydin-Ozemir, Zeynep; Terzibasioglu, Ege; Altindag, Ebru; Sencer, Serra; Baykan, Betul

2010-01-01

Studies investigating the pathophysiology of epileptic photosensitivity indicate variable involvement of particular brain regions. Our aim was to identify metabolic differences between photosensitive idiopathic generalized epilepsy (IGE) patients and nonphotosensitive IGE patients and normal healthy subjects by using Magnetic Resonance Spectroscopy (MRS). Fourteen patients diagnosed with photosensitive IGE were investigated. The control groups consisted of 14 age- and sex-matched healthy volunteers and 14 IGE patients without photosensitivity. MRS measurements of N-acetylaspartate (NAA), choline-containing compounds (Cho), creatine (Cr) were performed in the frontal and occipital cortex and the thalamus bilaterally using a stimulated echo acquisition mode (STEAM) technique with a voxel size of 20 x 20 x 20 mm. The values of the patients with IGE were compared with those of the normal controls and within subgroups according to the clinical variables by appropriate statistical tests. Photosensitive IGE patients showed significantly decreased concentrations of NAA in the right frontal lobe and left thalamus, decreased NAA/Cr ratio in left thalamus and significantly increased concentrations of Cho/Cr ratio in the right frontal lobe and NAA/Cr in the left occipital lobe when compared to normal controls. Furthermore, left occipital NAA concentration increased and left thalamus NAA/Cr ratios were decreased from the IGE patients without photosensitivity but without reaching statistical significance. Our results support previous MR studies suggesting an asymmetrical neuronal dysfunction in favor of the dominant occipital cortex and thalamus in photosensitive IGE patients.

Reduced N-acetylaspartate content in the frontal part of the brain in patients with probable Alzheimer's disease.

PubMed

Christiansen, P; Schlosser, A; Henriksen, O

1995-01-01

The fully relaxed water signal was used as an internal standard in a STEAM experiment to calculate the concentrations of the metabolites: N-acetylaspartate (NAA), creatine + phosphocreatine [Cr + PCr], and choline-containing metabolites (Cho) in the frontal part of the brain in 12 patients with probable Alzheimer's disease. Eight age-matched healthy volunteers served as controls. Furthermore, T1 and T2 relaxation times of the metabolites and signal ratios: NAA/Cho, NAA/[Cr + PCr], and [Cr + PCr]/Cho at four different echo times (TE) and two different repetition times (TR) were calculated. The experiments were carried out using a Siemens Helicon SP 63/84 wholebody MR-scanner at 1.5 T. The concentration of NAA was significantly lower in the patients with probable Alzheimer's disease than in the healthy volunteers. No significant difference was found for any other metabolite concentration. For the signal ratios the only statistically significant difference was that the NAA/Cho ratio at TE = 92 ms and TR = 1.6 s was lower in the patients with probable Alzheimer's disease compared with the control group. A trend towards a longer T2 relaxation time for NAA in the patients with probable Alzheimer's disease than among the healthy volunteers was found, but no significant difference was found concerning the T1 and T2 relaxation times.

Proteomic and genomic characterization of a yeast model for Ogden syndrome

PubMed Central

Dörfel, Max J.; Fang, Han; Crain, Jonathan; Klingener, Michael; Weiser, Jake

2016-01-01

Abstract Naa10 is an Nα‐terminal acetyltransferase that, in a complex with its auxiliary subunit Naa15, co‐translationally acetylates the α‐amino group of newly synthetized proteins as they emerge from the ribosome. Roughly 40–50% of the human proteome is acetylated by Naa10, rendering this an enzyme one of the most broad substrate ranges known. Recently, we reported an X‐linked disorder of infancy, Ogden syndrome, in two families harbouring a c.109 T > C (p.Ser37Pro) variant in NAA10. In the present study we performed in‐depth characterization of a yeast model of Ogden syndrome. Stress tests and proteomic analyses suggest that the S37P mutation disrupts Naa10 function and reduces cellular fitness during heat shock, possibly owing to dysregulation of chaperone expression and accumulation. Microarray and RNA‐seq revealed a pseudo‐diploid gene expression profile in ΔNaa10 cells, probably responsible for a mating defect. In conclusion, the data presented here further support the disruptive nature of the S37P/Ogden mutation and identify affected cellular processes potentially contributing to the severe phenotype seen in Ogden syndrome. Data are available via GEO under identifier GSE86482 or with ProteomeXchange under identifier PXD004923. © 2016 The Authors. Yeast published by John Wiley & Sons, Ltd. PMID:27668839

[Application of SPSS orthogonal design in tissue culture of Anoectochilus roxburghii].

PubMed

Zhang, Fusheng; Guo, Shunxing

2009-10-01

To study the effect of the different constitutions of plant hormone on the development of Anoectochilus roxburghii. A. roxburghii were harvested after having been cultured for 60 days. An orthogonal design was used to study the effect of NAA and 6-BA on the leaf number, eustipe number, lateral branch number of the stem tip and stem section, and the height of the stem tips. All of the data were processed by SPSS. It is reported for the first time that NAA could make different development of A. roxburghii at low concentration ( < 1 mg L(-1)) and high concentration ( > 1 mg L(-1)). The optimum constitution of MS medium was NAA 0.5 mg L(-1) + 6-BA 1 mg L(-1) for the growth of the stem tip of A. roxburghii, and NAA 1 mg L(-1) + 6-BA 2 mg L(-1) for the differentiation of bud and the formation of lateral branch of the stem section. The different concentrations of NAA and 6-BA had different effects on the growth and differentiation of the stem tip and the stem section of A. roxburghii.

[Clonal micropropagation of a rare species Hedysarum theinum Krasnob (Fabaceae) and assessment of the genetic stability of regenerated plants using ISSR markers].

PubMed

Erst, A A; Svyagina, N S; Novikova, T I; Dorogina, O V

2015-02-01

In the present study, a protocol was developed for the in vitro propagation of a rare medicinal plant, Hedysarum theinum (tea sweetvetch), from axillary buds, and identification of the regenerants was performed with the use of ISSR markers. It was demonstrated that Gamborg and Eveleigh medium supplemented with 5 μM 6-benzylaminopurine was the best for H. theinum for initial multiplication. On the other hand, half-strength Murashige and Skoog (MS) basal medium supplemented with 7 μM α-naphthaleneacetic acid proved to be the best for explant rooting. Molecular genetic analysis of the H. theinum mother plants and the obtained regenerants was performed with six ISSR markers. Depending on the primer, four to ten amplified fragments with sizes ranging from 250 to 3000 bp were identified. Our results confirmed the genetic stability of regenerants obtained in five passages and their identity to the mother plant.

An in vitro method for rapid regeneration of a monopodial orchid hybrid Aranda Deborah using thin section culture.

PubMed

Lakshmanan, P; Loh, C S; Goh, C J

1995-05-01

A thin section culture system for rapid regeneration of the monopodial orchid hybrid Aranda Deborah has been developed. Thin sections (0.6-0.7mm thick) obtained by transverse sectioning of a single shoot tip (6-7mm), when cultured in Vacin and Went medium enriched with coconut water (20% v/v), produced an average 13.6 protocorm-like bodies (PLB) after 45 days, compared to 2.7 PLB formed by a single 6-7 mm long shoot tip under same culture condition. Addition of α-naphthaleneacetic acid to Vacin and Went medium enriched with coconut water further increased PLB production by thin sections. PLB developed into plantlets on solid Vacin and Went medium containing 10% (v/v) coconut water and 0.5 g l(-1) activated charcoal. With this procedure, more than 80,000 plantlets could be produced from thin sections obtained from a single shoot tip in a year as compared to nearly 11,000 plantlets produced by the conventional shoot tip method.

Interferometric nanoporous anodic alumina photonic coatings for optical sensing

NASA Astrophysics Data System (ADS)

Chen, Yuting; Santos, Abel; Wang, Ye; Kumeria, Tushar; Wang, Changhai; Li, Junsheng; Losic, Dusan

2015-04-01

Herein, we present a systematic study on the development, optical optimization and sensing applicability of colored photonic coatings based on nanoporous anodic alumina films grown on aluminum substrates. These optical nanostructures, so-called distributed Bragg reflectors (NAA-DBRs), are fabricated by galvanostatic pulse anodization process, in which the current density is altered in a periodic manner in order to engineer the effective medium of the resulting photonic coatings. As-prepared NAA-DBR photonic coatings present brilliant interference colors on the surface of aluminum, which can be tuned at will within the UV-visible spectrum by means of the anodization profile. A broad library of NAA-DBR colors is produced by means of different anodization profiles. Then, the effective medium of these NAA-DBR photonic coatings is systematically assessed in terms of optical sensitivity, low limit of detection and linearity by reflectometric interference spectroscopy (RIfS) in order to optimize their nanoporous structure toward optical sensors with enhanced sensing performance. Finally, we demonstrate the applicability of these photonic nanostructures as optical platforms by selectively detecting gold(iii) ions in aqueous solutions. The obtained results reveal that optimized NAA-DBR photonic coatings can achieve an outstanding sensing performance for gold(iii) ions, with a sensitivity of 22.16 nm μM-1, a low limit of detection of 0.156 μM (i.e. 30.7 ppb) and excellent linearity within the working range (0.9983).Herein, we present a systematic study on the development, optical optimization and sensing applicability of colored photonic coatings based on nanoporous anodic alumina films grown on aluminum substrates. These optical nanostructures, so-called distributed Bragg reflectors (NAA-DBRs), are fabricated by galvanostatic pulse anodization process, in which the current density is altered in a periodic manner in order to engineer the effective medium of the resulting photonic coatings. As-prepared NAA-DBR photonic coatings present brilliant interference colors on the surface of aluminum, which can be tuned at will within the UV-visible spectrum by means of the anodization profile. A broad library of NAA-DBR colors is produced by means of different anodization profiles. Then, the effective medium of these NAA-DBR photonic coatings is systematically assessed in terms of optical sensitivity, low limit of detection and linearity by reflectometric interference spectroscopy (RIfS) in order to optimize their nanoporous structure toward optical sensors with enhanced sensing performance. Finally, we demonstrate the applicability of these photonic nanostructures as optical platforms by selectively detecting gold(iii) ions in aqueous solutions. The obtained results reveal that optimized NAA-DBR photonic coatings can achieve an outstanding sensing performance for gold(iii) ions, with a sensitivity of 22.16 nm μM-1, a low limit of detection of 0.156 μM (i.e. 30.7 ppb) and excellent linearity within the working range (0.9983). Electronic supplementary information (ESI) available: The Supporting Information file provides further information about real-time monitoring of ΔOTeff with changes in the refractive index of the medium filling the nanopores, demonstration of visual red shift in a NAA-DBR sample after infiltration with isopropanol and calculations of linearity (R2) for each NAA-DBR coating. See DOI: 10.1039/c5nr00369e

Resistance of the Opossum (Didelphis Virginiana) to Envenomation by Snakes of the Crotalidae Family.

DTIC Science & Technology

1976-12-01

ni., .d in Eiock 20. If dtli.r., ( ha. R.p.f ) IS S UPPL€ MEN TA RY NOTES Animal studies in relation to chemical agents 5 I E Y WO RDS (Co&Mu. ., r...cobra 1 .07 mg/kg, iv Died in 30 mm Na/a na/a atra 0 Snakebite Died in 45 min Chinese cobra Na/a nivea 03 1.38 mg/kg, iv Died in 1 hr Cape cobra Micn

3-Dimensional magnetic resonance spectroscopic imaging at 3 Tesla for early response assessment of glioblastoma patients during external beam radiation therapy.

PubMed

Muruganandham, Manickam; Clerkin, Patrick P; Smith, Brian J; Anderson, Carryn M; Morris, Ann; Capizzano, Aristides A; Magnotta, Vincent; McGuire, Sarah M; Smith, Mark C; Bayouth, John E; Buatti, John M

2014-09-01

To evaluate the utility of 3-dimensional magnetic resonance (3D-MR) proton spectroscopic imaging for treatment planning and its implications for early response assessment in glioblastoma multiforme. Eighteen patients with newly diagnosed, histologically confirmed glioblastoma had 3D-MR proton spectroscopic imaging (MRSI) along with T2 and T1 gadolinium-enhanced MR images at simulation and at boost treatment planning after 17 to 20 fractions of radiation therapy. All patients received standard radiation therapy (RT) with concurrent temozolomide followed by adjuvant temozolomide. Imaging for response assessment consisted of MR scans every 2 months. Progression-free survival was defined by the criteria of MacDonald et al. MRSI images obtained at initial simulation were analyzed for choline/N-acetylaspartate ratios (Cho/NAA) on a voxel-by-voxel basis with abnormal activity defined as Cho/NAA ≥2. These images were compared on anatomically matched MRSI data collected after 3 weeks of RT. Changes in Cho/NAA between pretherapy and third-week RT scans were tested using Wilcoxon matched-pairs signed rank tests and correlated with progression-free survival, radiation dose and location of recurrence using Cox proportional hazards regression. After a median follow-up time of 8.6 months, 50% of patients had experienced progression based on imaging. Patients with a decreased or stable mean or median Cho/NAA values had less risk of progression (P<.01). Patients with an increase in mean or median Cho/NAA values at the third-week RT scan had a significantly greater chance of early progression (P<.01). An increased Cho/NAA at the third-week MRSI scan carried a hazard ratio of 2.72 (95% confidence interval, 1.10-6.71; P=.03). Most patients received the prescription dose of RT to the Cho/NAA ≥2 volume, where recurrence most often occurred. Change in mean and median Cho/NAA detected at 3 weeks was a significant predictor of early progression. The potential impact for risk-adaptive therapy based on early spectroscopic findings is suggested. Published by Elsevier Inc.

3D-MR Spectroscopic Imaging at 3Tesla for Early Response Assessment of Glioblastoma Patients during External Beam Radiation Therapy

PubMed Central

Muruganandham, Manickam; Clerkin, Patrick P; Smith, Brian J; Anderson, Carryn M; Morris, Ann; Capizzano, Aristides A; Magnotta, Vincent; McGuire, Sarah M; Smith, Mark C; Bayouth, John E; Buatti, John M

2014-01-01

Purpose To evaluate the utility of 3D-MR proton spectroscopic imaging for treatment planning and its implications for early response assessment in glioblastoma multiforme. Methods and Materials Eighteen patients with newly diagnosed, histologically confirmed glioblastoma had 3D-MR proton spectroscopic imaging (MRSI) along with T2 and T1 gadolinium enhanced MR images at simulation and at boost treatment planning after 17-20 fractions of radiotherapy. All patients received standard radiotherapy with temozolomide and follow-up with every two month MR scans. Progression free survival was defined using MacDonald criteria. MRSI images obtained at initial simulation were analyzed for choline / N-acetylaspartate ratios (Cho/NAA) on a voxel by voxel basis with abnormal activity defined as Cho/NAA ≥ 2. These images were compared on anatomically matched MRSI data collected after 3 weeks of radiotherapy. Changes in Cho/NAA between pre-therapy and 3rd week RT scans were tested using Wilcoxon matched-pairs signed rank tests and correlated with progression free survival, radiation dose and location of recurrence using Cox proportional hazards regression. Results After 8.6 months (median follow-up), 50% of patients had progressed based on imaging. Patients with a decreased or stable mean or median Cho/NAA values had less risk of progression (p< 0.01). Patients with an increase in mean or median Cho/NAA values at the 3rd week RT scan had a significantly greater chance of early progression (p <0.01). An increased Cho/NAA at the 3rd week MRSI scan carried a hazard ratio of 2.72 (95% confidence interval 1.10-6.71, p= 0.03). Most patients received the prescription dose of RT to the Cho/NAA ≥ 2 volume, which was where recurrence most often occurred. Conclusion Change in mean and median Cho/NAA detected at 3 weeks was a significant predictor of early progression. The potential impact for risk-adaptive therapy based on early spectroscopic findings is suggested. PMID:24986746

3-Dimensional Magnetic Resonance Spectroscopic Imaging at 3 Tesla for Early Response Assessment of Glioblastoma Patients During External Beam Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muruganandham, Manickam; Clerkin, Patrick P.; Smith, Brian J.

Purpose: To evaluate the utility of 3-dimensional magnetic resonance (3D-MR) proton spectroscopic imaging for treatment planning and its implications for early response assessment in glioblastoma multiforme. Methods and Materials: Eighteen patients with newly diagnosed, histologically confirmed glioblastoma had 3D-MR proton spectroscopic imaging (MRSI) along with T2 and T1 gadolinium-enhanced MR images at simulation and at boost treatment planning after 17 to 20 fractions of radiation therapy. All patients received standard radiation therapy (RT) with concurrent temozolomide followed by adjuvant temozolomide. Imaging for response assessment consisted of MR scans every 2 months. Progression-free survival was defined by the criteria of MacDonald et al.more » MRSI images obtained at initial simulation were analyzed for choline/N-acetylaspartate ratios (Cho/NAA) on a voxel-by-voxel basis with abnormal activity defined as Cho/NAA ≥2. These images were compared on anatomically matched MRSI data collected after 3 weeks of RT. Changes in Cho/NAA between pretherapy and third-week RT scans were tested using Wilcoxon matched-pairs signed rank tests and correlated with progression-free survival, radiation dose and location of recurrence using Cox proportional hazards regression. Results: After a median follow-up time of 8.6 months, 50% of patients had experienced progression based on imaging. Patients with a decreased or stable mean or median Cho/NAA values had less risk of progression (P<.01). Patients with an increase in mean or median Cho/NAA values at the third-week RT scan had a significantly greater chance of early progression (P<.01). An increased Cho/NAA at the third-week MRSI scan carried a hazard ratio of 2.72 (95% confidence interval, 1.10-6.71; P=.03). Most patients received the prescription dose of RT to the Cho/NAA ≥2 volume, where recurrence most often occurred. Conclusion: Change in mean and median Cho/NAA detected at 3 weeks was a significant predictor of early progression. The potential impact for risk-adaptive therapy based on early spectroscopic findings is suggested.« less

76 FR 75845 - Approval and Promulgation of Implementation Plans; State of Tennessee: Prevention of Significant...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-05

... major stationary thresholds (marginal, moderate, serious, severe, and extreme NAA classifications) and... offset ratios for marginal, moderate, serious, severe, and extreme ozone NAA. EPA finalized regulations...

Single voxel magnetic resonance spectroscopy at 3 Tesla in a memory disorders clinic: early right hippocampal NAA/Cr loss in mildly impaired subjects.

PubMed

Caserta, Maria T; Ragin, Ann; Hermida, Adriana P; Ahrens, R John; Wise, Leon

2008-11-30

In this study, we use magnetic resonance spectroscopy (MRS) at 3 Tesla to measure N-acetyl aspartate (NAA), myo-inositol (mI) and choline (Cho) to creatine (Cr) ratios in R (right) and L (left) hippocampi (H) in 8 mildly memory impaired (MMI), 6 probable Alzheimer's Disease (PRAD), and 17 control subjects. NAA/Cr was significantly reduced in the RH in the MMI group and bilaterally in the PRAD group vs. controls. No other metabolite differences were noted between the three groups. Five MMI subjects have converted to PRAD in follow-up. These findings suggest that RH NAA/Cr ratios measured at 3 Tesla may be a sensitive marker of future progression to dementia in a clinically defined population with isolated memory complaints.

Nanoporous Anodic Alumina Platforms: Engineered Surface Chemistry and Structure for Optical Sensing Applications

PubMed Central

Kumeria, Tushar; Santos, Abel; Losic, Dusan

2014-01-01

Electrochemical anodization of pure aluminum enables the growth of highly ordered nanoporous anodic alumina (NAA) structures. This has made NAA one of the most popular nanomaterials with applications including molecular separation, catalysis, photonics, optoelectronics, sensing, drug delivery, and template synthesis. Over the past decades, the ability to engineer the structure and surface chemistry of NAA and its optical properties has led to the establishment of distinctive photonic structures that can be explored for developing low-cost, portable, rapid-response and highly sensitive sensing devices in combination with surface plasmon resonance (SPR) and reflective interference spectroscopy (RIfS) techniques. This review article highlights the recent advances on fabrication, surface modification and structural engineering of NAA and its application and performance as a platform for SPR- and RIfS-based sensing and biosensing devices. PMID:25004150

Molecular simulation of water removal from simple gases with zeolite NaA.

PubMed

Csányi, Eva; Ható, Zoltán; Kristóf, Tamás

2012-06-01

Water vapor removal from some simple gases using zeolite NaA was studied by molecular simulation. The equilibrium adsorption properties of H(2)O, CO, H(2), CH(4) and their mixtures in dehydrated zeolite NaA were computed by grand canonical Monte Carlo simulations. The simulations employed Lennard-Jones + Coulomb type effective pair potential models, which are suitable for the reproduction of thermodynamic properties of pure substances. Based on the comparison of the simulation results with experimental data for single-component adsorption at different temperatures and pressures, a modified interaction potential model for the zeolite is proposed. In the adsorption simulations with mixtures presented here, zeolite exhibits extremely high selectivity of water to the investigated weakly polar/non-polar gases demonstrating the excellent dehydration ability of zeolite NaA in engineering applications.

A single dose of a neuron-binding human monoclonal antibody improves brainstem NAA concentrations, a biomarker for density of spinal cord axons, in a model of progressive multiple sclerosis.

PubMed

Wootla, Bharath; Denic, Aleksandar; Watzlawik, Jens O; Warrington, Arthur E; Rodriguez, Moses

2015-04-29

Intracerebral infection of susceptible mouse strains with Theiler's murine encephalomyelitis virus (TMEV) results in chronic demyelinating disease with progressive axonal loss and neurologic dysfunction similar to progressive forms of multiple sclerosis (MS). We previously showed that as the disease progresses, a marked decrease in brainstem N-acetyl aspartate (NAA; metabolite associated with neuronal integrity) concentrations, reflecting axon health, is measured. We also demonstrated stimulation of neurite outgrowth by a neuron-binding natural human antibody, IgM12. Treatment with either the serum-derived or recombinant human immunoglobulin M 12 (HIgM12) preserved functional motor activity in the TMEV model. In this study, we examined IgM-mediated changes in brainstem NAA concentrations and central nervous system (CNS) pathology. (1)H-magnetic resonance spectroscopy (MRS) showed that treatment with HIgM12 significantly increased brainstem NAA concentrations compared to controls in TMEV-infected mice. Pathologic analysis demonstrated a significant preservation of axons in the spinal cord of animals treated with HIgM12. This study links drug efficacy of slowing deficits with axon preservation and NAA concentrations in the brainstem in a model of progressive MS. HIgM12-mediated changes of NAA concentrations in the brainstem are a surrogate marker of axon injury/preservation throughout the spinal cord. This study provides proof-of-concept that a neuron-reactive human IgM can be therapeutic and provides a biomarker for clinical trials.

Education mitigates age-related decline in N-Acetylaspartate levels.

PubMed

Erickson, Kirk I; Leckie, Regina L; Weinstein, Andrea M; Radchenkova, Polina; Sutton, Bradley P; Prakash, Ruchika Shaurya; Voss, Michelle W; Chaddock-Heyman, Laura; McAuley, Edward; Kramer, Arthur F

2015-03-01

Greater educational attainment is associated with better neurocognitive health in older adults and is thought to reflect a measure of cognitive reserve. In vivo neuroimaging tools have begun to identify the brain systems and networks potentially responsible for reserve. We examined the relationship between education, a commonly used proxy for cognitive reserve, and N-acetylaspartate (NAA) in neurologically healthy older adults (N=135; mean age=66 years). Using single voxel MR spectroscopy, we predicted that higher levels of education would moderate an age-related decline in NAA in the frontal cortex. After controlling for the variance associated with cardiorespiratory fitness, sex, annual income, and creatine levels, there were no significant main effects of education (B=0.016, P=0.787) or age (B=-0.058, P=0.204) on NAA levels. However, consistent with our predictions, there was a significant education X age interaction such that more years of education offset an age-related decline in NAA (B=0.025, P=0.031). When examining working memory via the backwards digit span task, longer span length was associated with greater education (P<0.01) and showed a trend with greater NAA concentrations (P<0.06); however, there was no age X education interaction on digit span performance nor a significant moderated mediation effect between age, education, and NAA on digit span performance. Taken together, these results suggest that higher levels of education may attenuate an age-related reduction in neuronal viability in the frontal cortex.

Education mitigates age-related decline in N-Acetylaspartate levels

PubMed Central

Erickson, Kirk I; Leckie, Regina L; Weinstein, Andrea M; Radchenkova, Polina; Sutton, Bradley P; Prakash, Ruchika Shaurya; Voss, Michelle W; Chaddock-Heyman, Laura; McAuley, Edward; Kramer, Arthur F

2015-01-01

Background Greater educational attainment is associated with better neurocognitive health in older adults and is thought to reflect a measure of cognitive reserve. In vivo neuroimaging tools have begun to identify the brain systems and networks potentially responsible for reserve. Methods We examined the relationship between education, a commonly used proxy for cognitive reserve, and N-acetylaspartate (NAA) in neurologically healthy older adults (N = 135; mean age = 66 years). Using single voxel MR spectroscopy, we predicted that higher levels of education would moderate an age-related decline in NAA in the frontal cortex. Results After controlling for the variance associated with cardiorespiratory fitness, sex, annual income, and creatine levels, there were no significant main effects of education (B = 0.016, P = 0.787) or age (B = −0.058, P = 0.204) on NAA levels. However, consistent with our predictions, there was a significant education X age interaction such that more years of education offset an age-related decline in NAA (B = 0.025, P = 0.031). When examining working memory via the backwards digit span task, longer span length was associated with greater education (P < 0.01) and showed a trend with greater NAA concentrations (P < 0.06); however, there was no age X education interaction on digit span performance nor a significant moderated mediation effect between age, education, and NAA on digit span performance. Conclusions Taken together, these results suggest that higher levels of education may attenuate an age-related reduction in neuronal viability in the frontal cortex. PMID:25798329

Neuronal loss is an early component of subacute sclerosing panencephalitis.

PubMed

Yüksel, Deniz; Diren, Barış; Ulubay, Hakan; Altunbaşak, Sakir; Anlar, Banu

2014-09-02

We performed diffusion tensor imaging (DTI) and magnetic resonance spectroscopy (MRS) studies in a group of patients with subacute sclerosing panencephalitis (SSPE) in order to estimate the pathologic process underlying the phenotypic variability. Patients with SSPE who had MRI including DTI and MRS examinations were evaluated according to their clinical status as determined by the SSPE Scoring System and their mental age as determined by tests appropriate for age and developmental level. Comparisons of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values and metabolite ratios of frontal periventricular white matter, parieto-occipital periventricular white matter, and globus pallidus in both hemispheres were made between control and SSPE groups, and between SSPE subgroups. Control (n = 18) and SSPE (n = 39) groups differed in all DTI and MRS parameters except FA, choline (Cho), and Cho/creatine (Cr). SSPE cases had higher ADC and lower N-acetylaspartate (NAA), NAA/Cho, and NAA/Cr in all regions of interest, suggesting cell loss. Disease progression rate and neurologic deficit appeared to be associated with the degree of ADC elevation and NAA reduction: the group with severe global deterioration had the lowest NAA (230.75 ± 197.97 in forceps minor), and rapid progression was associated with acute reduction in NAA. The combination of MRS and diffusion MRI findings suggests neuronal loss can be a primary target in rapidly or subacutely progressing SSPE, and preservation or regeneration of axonal structure may be beneficial in chronic cases. © 2014 American Academy of Neurology.

In vitro propagation and assessment of the genetic fidelity of Musa acuminata (AAA) cv. Vaibalhla derived from immature male flowers.

PubMed

Hrahsel, Lalremsiami; Basu, Adreeja; Sahoo, Lingaraj; Thangjam, Robert

2014-02-01

An efficient in vitro propagation method has been developed for the first time for Musa acuminata (AAA) cv. Vaibalhla, an economically important banana cultivar of Mizoram, India. Immature male flowers were used as explants. Murashige and Skoog's (MS) medium supplemented with plant growth regulators (PGRs) were used for the regeneration process. Out of different PGR combinations, MS medium supplemented with 2 mg L(-1) 6-benzylaminopurine (BAP) + 0.5 mg L(-1) α-naphthalene acetic acid (NAA) was optimal for production of white bud-like structures (WBLS). On this medium, explants produced the highest number of buds per explant (4.30). The highest percentage (77.77) and number (3.51) of shoot formation from each explants was observed in MS medium supplemented with 2 mg L(-1) kinetin + 0.5 mg L(-1) NAA. While MS medium supplemented with a combination of 2 mg L(-1) BAP + 0.5 mg L(-1) NAA showed the maximum shoot length (14.44 cm). Rooting efficiency of the shoots was highest in the MS basal medium without any PGRs. The plantlets were hardened successfully in the greenhouse with 96% survival rate. Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers were employed to assess the genetic stability of in vitro regenerated plantlets of M. acuminata (AAA) cv. Vaibalhla. Eight RAPD and 8 ISSR primers were successfully used for the analysis from the 40 RAPD and 30 ISSR primers screened initially. The amplified products were monomorphic across all the regenerated plants and were similar to the mother plant. The present standardised protocol will find application in mass production, conservation and genetic transformation studies of this commercially important banana.

Frontal Metabolite Concentration Deficits in Opiate Dependence Relate to Substance Use, Cognition, and Self-Regulation

PubMed Central

Murray, Donna E; Durazzo, Timothy C; Schmidt, Thomas P; Abé, Christoph; Guydish, Joseph; Meyerhoff, Dieter J

2016-01-01

Objective Proton magnetic resonance spectroscopy (1H MRS) in opiate dependence showed abnormalities in neuronal viability and glutamate concentration in the anterior cingulate cortex (ACC). Metabolite levels in dorsolateral prefrontal cortex (DLPFC) or orbitofrontal cortex (OFC) and their neuropsychological correlates have not been investigated in opiate dependence. Methods Single-volume proton MRS at 4 Tesla and neuropsychological testing were conducted in 21 opiate-dependent individuals (OD) on buprenorphine maintenance therapy. Results were compared to 28 controls (CON) and 35 alcohol-dependent individuals (ALC), commonly investigated treatment-seekers providing context for OD evaluation. Metabolite concentrations were measured from ACC, DLPFC, OFC and parieto-occipital cortical (POC) regions. Results Compared to CON, OD had lower concentrations of N-acetylaspartate (NAA), glutamate (Glu), creatine +phosphocreatine (Cr) and myo-Inositol (mI) in the DLPFC and lower NAA, Cr, and mI in the ACC. OD, ALC, and CON were equivalent on metabolite levels in the POC and γ-aminobutyric acid (GABA) concentration did not differ between groups in any region. In OD, prefrontal metabolite deficits in ACC Glu as well as DLPFC NAA and choline containing metabolites (Cho) correlated with poorer working memory, executive and visuospatial functioning; metabolite deficits in DLPFC Glu and ACC GABA and Cr correlated with substance use measures. In the OFC of OD, Glu and choline-containing metabolites were elevated and lower Cr concentration related to higher nonplanning impulsivity. Compared to 3 week abstinent ALC, OD had significant DLPFC metabolite deficits. Conclusion The anterior frontal metabolite profile of OD differed significantly from that of CON and ALC. The frontal lobe metabolite abnormalities in OD and their neuropsychological correlates may play a role in treatment outcome and could be explored as specific targets for improved OD treatment. PMID:27695638

Quaternized Cellulose Hydrogels as Sorbent Materials and Pickering Emulsion Stabilizing Agents

PubMed Central

Udoetok, Inimfon A.; Wilson, Lee D.; Headley, John V.

2016-01-01

Quaternized (QC) and cross-linked/quaternized (CQC) cellulose hydrogels were prepared by cross-linking native cellulose with epichlorohydrin (ECH), with subsequent grafting of glycidyl trimethyl ammonium chloride (GTMAC). Materials characterization via carbon, hydrogen and nitrogen (CHN) analysis, thermogravimetric analysis (TGA), and Fourier transform infrared (FTIR)/13C solid state NMR spectroscopy provided supportive evidence of the hydrogel synthesis. Enhanced thermal stability of the hydrogels was observed relative to native cellulose. Colloidal stability of octanol and water mixtures revealed that QC induces greater stabilization over CQC, as evidenced by the formation of a hexane–water Pickering emulsion system. Equilibrium sorption studies with naphthenates from oil sands process water (OSPW) and 2-naphthoxy acetic acid (NAA) in aqueous solution revealed that CQC possess higher affinity relative to QC with the naphthenates. According to the Langmuir isotherm model, the sorption capacity of CQC for OSPW naphthenates was 33.0 mg/g and NAA was 69.5 mg/g. CQC displays similar affinity for the various OSPW naphthenate component species in aqueous solution. Kinetic uptake of NAA at variable temperature, pH and adsorbent dosage showed that increased temperature favoured the uptake process at 303 K, where Qm = 76.7 mg/g. Solution conditions at pH 3 or 9 had a minor effect on the sorption process, while equilibrium was achieved in a shorter time at lower dosage (ca. three-fold lower) of hydrogel (100 mg vs. 30 mg). The estimated activation parameters are based on temperature dependent rate constants, k1, which reveal contributions from enthalpy-driven electrostatic interactions. The kinetic results indicate an ion-based associative sorption mechanism. This study contributes to a greater understanding of the adsorption and physicochemical properties of cellulose-based hydrogels. PMID:28773767

A safety trial of high dose glyceryl triacetate for Canavan disease.

PubMed

Segel, Reeval; Anikster, Yair; Zevin, Shoshana; Steinberg, Avraham; Gahl, William A; Fisher, Drora; Staretz-Chacham, Orna; Zimran, Ari; Altarescu, Gheona

2011-07-01

Canavan disease (CD MIM#271900) is a rare autosomal recessive neurodegenerative disorder presenting in early infancy. The course of the disease is variable, but it is always fatal. CD is caused by mutations in the ASPA gene, which codes for the enzyme aspartoacylase (ASPA), which breaks down N-acetylaspartate (NAA) to acetate and aspartic acid. The lack of NAA-degrading enzyme activity leads to excess accumulation of NAA in the brain and deficiency of acetate, which is necessary for myelin lipid synthesis. Glyceryltriacetate (GTA) is a short-chain triglyceride with three acetate moieties on a glycerol backbone and has proven an effective acetate precursor. Intragastric administration of GTA to tremor mice results in greatly increased brain acetate levels, and improved motor functions. GTA given to infants with CD at a low dose (up to 0.25 g/kg/d) resulted in no improvement in their clinical status, but also no detectable toxicity. We present for the first time the safety profile of high dose GTA (4.5 g/kg/d) in 2 patients with CD. We treated 2 infants with CD at ages 8 months and 1 year with high dose GTA, for 4.5 and 6 months respectively. No significant side effects and no toxicity were observed. Although the treatment resulted in no motor improvement, it was well tolerated. The lack of clinical improvement might be explained mainly by the late onset of treatment, when significant brain damage was already present. Further larger studies of CD patients below age 3 months are required in order to test the long-term efficacy of this drug. Copyright © 2011 Elsevier Inc. All rights reserved.

The concentration of N-acetyl aspartate, creatine + phosphocreatine, and choline in different parts of the brain in adulthood and senium.

PubMed

Christiansen, P; Toft, P; Larsson, H B; Stubgaard, M; Henriksen, O

1993-01-01

The fully relaxed water signal was used as an internal standard in a STEAM experiment to calculate the concentrations of the metabolites: N-acetyl aspartate (NAA), creatine + phosphocreatine (Cr + PCr), and choline (Cho) containing compounds in four different parts of the brain in two age groups of healthy volunteers (20-30 yr, n = 8) and (60-80 yr, n = 8). Furthermore, T1 and T2 relaxation time of the metabolites and signal ratios: NAA/Cho, NAA/Cr + PCr, and Cho/Cr + PCr at TE = 272 msec were calculated. The experiments were carried out using a Siemens Helicon SP 63/84 wholebody MR-scanner at 1.5 T. In the younger age group, the concentration of NAA was significantly higher in the occipital part than in the other three parts of the brain. No significant regional variation was found for any other metabolite concentration. There was a significantly higher concentration of NAA in the occipital part of the brain in the younger age group compared to the older one. No significant regional or age dependent variation was found concerning the T1 and T2 relaxation times.

Vegetative propagation of Cecropia obtusifolia (Cecropiaceae).

PubMed

LaPierre, L M

2001-01-01

Cecropia is a relatively well-known and well-studied genus in the Neotropics. Methods for the successful propagation of C. obtusifolia Bertoloni, 1840 from cuttings and air layering are described, and the results of an experiment to test the effect of two auxins, naphthalene acetic acid (NAA) and indole butyric acid (IBA), on adventitious root production in cuttings are presented. In general, C. obtusifolia cuttings respond well to adventitious root production (58.3% of cuttings survived to root), but air layering was the better method (93% of cuttings survived to root). The concentration of auxins used resulted in an overall significantly lower quality of roots produced compared with cuttings without auxin treatment. Future experiments using Cecropia could benefit from the use of isogenic plants produced by vegetative propagation.

Low Seismic Attenuation in Southern New England Lithosphere Implies Little Heating by the Upwelling Asthenosphere

NASA Astrophysics Data System (ADS)

Lamoureux, J. M.; Menke, W. H.

2017-12-01

The Northern Appalachian Anomaly (NAA) is a patch of the asthenosphere in southern New England that is unusually hot given its passive margin setting. Previous research has detected large seismic wave delays that imply a temperature of 770 deg C higher than the mantle below the adjacent craton at the same depth. A key outstanding issue is whether the NAA interacts with the lithosphere above it (e.g. by heating it up). We study this issue using Po and So waves from two magnitude >5.5 earthquakes near the Puerto Rico Trench. These waves, propagating in the cold oceanic lithosphere at near Moho speeds, deliver high frequency energy to the shallow continental lithosphere. We hypothesized that: (1) once within the continental lithosphere, Po and So experience attenuation with distance that can be quantified by a quality factor Q, and that (2) any heating of the lithosphere above the NAA would lead to a higher Q than in regions further north or south along the continental margin. Corresponding Po and So velocities would also be lower. The decay rates of Po and So are estimated using least-squares applied to RMS coda amplitudes measured from digital seismograms from stations in northeastern North America, corrected for instrument response. A roughly log-linear decrease in amplitude is observed, corresponding to P and S wave quality factors in the range of 394-1500 and 727-6847, respectively. Measurements are made for four margin-perpendicular geographical bands, with one band overlapping the NAA. We detect no effect on these amplitudes by the NAA; 95% confidence bounds overlap in every case; Furthermore, all quality factors are much higher than the 100 predicted by lab experiments for near-solidus mantle rocks. These results suggest that the NAA is not causing significant heating of the lithosphere above it. The shear velocities, however, are about 10% slower above the NAA - an effect that may be fossil, reflecting processes that occurred millions of years ago.

A Critical Proton MR Spectroscopy Marker of Alzheimer's Disease Early Neurodegenerative Change: Low Hippocampal NAA/Cr Ratio Impacts APOE ɛ4 Mexico City Children and Their Parents.

PubMed

Calderón-Garcidueñas, Lilian; Mora-Tiscareño, Antonieta; Melo-Sánchez, Gastón; Rodríguez-Díaz, Joel; Torres-Jardón, Ricardo; Styner, Martin; Mukherjee, Partha S; Lin, Weili; Jewells, Valerie

2015-01-01

Severe air pollution exposures produce systemic, respiratory, myocardial, and brain inflammation and Alzheimer's disease (AD) hallmarks in clinically healthy children. We tested whether hippocampal metabolite ratios are associated with contrasting levels of air pollution, APOE, and body mass index (BMI) in paired healthy children and one parent sharing the same APOE alleles. We used 1H-MRS to interrogate bilateral hippocampal single-voxel in 57 children (12.45 ± 3.4 years) and their 48 parents (37.5 ± 6.78 years) from a low pollution city versus Mexico City (MC). NAA/Cr, Cho/Cr, and mI/Cr metabolite ratios were analyzed. The right hippocampus NAA/Cr ratio was significantly different between cohorts (p = 0.007). The NAA/Cr ratio in right hippocampus in controls versus APOE ɛ4 MC children and in left hippocampus in MC APOE ɛ4 parents versus their children was significantly different after adjusting for age, gender, and BMI (p = 0.027 and 0.01, respectively). The NAA/Cr ratio is considered reflective of neuronal density/functional integrity/loss of synapses/higher pTau burden, thus a significant decrease in hippocampal NAA/Cr ratios may constitute a spectral marker of early neurodegeneration in young urbanites. Decreases in NAA/Cr correlate well with cognitive function, behavioral symptoms, and dementia severity; thus, since the progression of AD starts decades before clinical diagnosis, our findings support the hypothesis that under chronic exposures to fine particulate matter and ozone above the standards, neurodegenerative processes start in childhood and APOE ɛ4 carriers are at higher risk. Gene and environmental factors are critical in the development of AD and the identification and neuroprotection of young urbanites at high risk must become a public health priority.

Cortical thickness and metabolite concentration in chronic stroke and the relationship with motor function

PubMed Central

Jones, Paul W.; Borich, Michael R.; Vavsour, Irene; Mackay, Alex; Boyd, Lara A.

2016-01-01

Introduction Hemiparesis is one of the most prevalent chronic disabilities after stroke. Biochemical and structural magnetic resonance imaging approaches may be employed to study the neural substrates underpinning upper-extremity (UE) recovery after chronic stroke. Objective The purposes of this study were to 1) quantify anatomical and metabolic differences in the precentral gyrus, and 2) test the relationships between anatomical and metabolic differences, and hemiparetic arm function in individuals in the chronic stage of stroke recovery. Our hypotheses were: 1) the Stroke group would exhibit reduced precentral gyrus cortical thickness and lower concentrations of total N-acetylaspartate (tNAA) and glutamate+glutamine (Glx) in the ipsilesional motor cortex; and 2) that each of these measures would be associated with UE motor function after stroke. Methods Seventeen individuals with chronic (>6 months) subcortical ischemic stroke and eleven neurologically healthy controls were recruited. Single voxel proton magnetic resonance spectroscopy (H1MRS) was performed to measure metabolite concentrations of tNAA and Glx in the precentral gyrus in both ipsilesional and contralesional hemispheres. Surface-based cortical morphometry was used to quantify precentral gyral thickness. Upper-extremity motor function was assessed using the Wolf Motor Function Test (WMFT). Results Results demonstrated significantly lower ipsilesional tNAA and Glx concentrations and precentral gyrus thickness in the Stroke group. Ipsilesional tNAA and Glx concentration and precentral gyrus thickness was significantly lower in the ipsilesional hemisphere in the Stroke group. Parametric correlation analyses revealed a significant positive relationship between precentral gyrus thickness and tNAA concentration bilaterally. Multivariate regression analyses revealed that ipsilesional concentrations of tNAA and Glx predicted the largest amount of variance in WMFT scores. Cortical thickness measures alone did not predict a significant amount of variance in WMFT scores. Conclusions While stroke impairs both structure and biochemistry in the ipsilesional hemisphere our data suggest that tNAA has the strongest relationship with motor function. PMID:27258945

Cortical thickness and metabolite concentration in chronic stroke and the relationship with motor function.

PubMed

Jones, Paul W; Borich, Michael R; Vavsour, Irene; Mackay, Alex; Boyd, Lara A

2016-09-21

Hemiparesis is one of the most prevalent chronic disabilities after stroke. Biochemical and structural magnetic resonance imaging approaches may be employed to study the neural substrates underpinning upper-extremity (UE) recovery after chronic stroke. The purposes of this study were to 1) quantify anatomical and metabolic differences in the precentral gyrus, and 2) test the relationships between anatomical and metabolic differences, and hemiparetic arm function in individuals in the chronic stage of stroke recovery. Our hypotheses were: 1) the Stroke group would exhibit reduced precentral gyrus cortical thickness and lower concentrations of total N-acetylaspartate (tNAA) and glutamate+glutamine (Glx) in the ipsilesional motor cortex; and 2) that each of these measures would be associated with UE motor function after stroke. Seventeen individuals with chronic (>6 months) subcortical ischemic stroke and eleven neurologically healthy controls were recruited. Single voxel proton magnetic resonance spectroscopy (H1MRS) was performed to measure metabolite concentrations of tNAA and Glx in the precentral gyrus in both ipsilesional and contralesional hemispheres. Surface-based cortical morphometry was used to quantify precentral gyral thickness. Upper-extremity motor function was assessed using the Wolf Motor Function Test (WMFT). Results demonstrated significantly lower ipsilesional tNAA and Glx concentrations and precentral gyrus thickness in the Stroke group. Ipsilesional tNAA and Glx concentration and precentral gyrus thickness was significantly lower in the ipsilesional hemisphere in the Stroke group. Parametric correlation analyses revealed a significant positive relationship between precentral gyrus thickness and tNAA concentration bilaterally. Multivariate regression analyses revealed that ipsilesional concentrations of tNAA and Glx predicted the largest amount of variance in WMFT scores. Cortical thickness measures alone did not predict a significant amount of variance in WMFT scores. While stroke impairs both structure and biochemistry in the ipsilesional hemisphere our data suggest that tNAA has the strongest relationship with motor function.

77 FR 30886 - Virginia Graeme Baker Pool and Spa Safety Act; Interpretation of Unblockable Drain

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-24

.... The commenter, the National Multi Housing Council/ National Apartment Association (NMHC/NAA... with compliance, the majority of their members could comply by the deadline; but NMHC/NAA urged the...

Purification and characterization of aspartate N-acetyltransferase: A critical enzyme in brain metabolism.

PubMed

Wang, Qinzhe; Zhao, Mojun; Parungao, Gwenn G; Viola, Ronald E

2016-03-01

Canavan disease (CD) is a neurological disorder caused by an interruption in the metabolism of N-acetylaspartate (NAA). Numerous mutations have been found in the enzyme that hydrolyzes NAA, and the catalytic activity of aspartoacylase is significantly impaired in CD patients. Recent studies have also supported an important role in CD for the enzyme that catalyzes the synthesis of NAA in the brain. However, previous attempts to study this enzyme had not succeeded in obtaining a soluble, stable and active form of this membrane-associated protein. We have now utilized fusion constructs with solubilizing protein partners to obtain an active and soluble form of aspartate N-acetyltransferase. Characterization of the properties of this enzyme has set the stage for the development of selective inhibitors that can lower the elevated levels of NAA that are observed in CD patients and potentially serve as a new treatment therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

Neutron Activation Analysis of the Rare Earth Elements (REE) - With Emphasis on Geological Materials

NASA Astrophysics Data System (ADS)

Stosch, Heinz-Günter

2016-08-01

Neutron activation analysis (NAA) has been the analytical method of choice for rare earth element (REE) analysis from the early 1960s through the 1980s. At that time, irradiation facilitieswere widely available and fairly easily accessible. The development of high-resolution gamma-ray detectors in the mid-1960s eliminated, formany applications, the need for chemical separation of the REE from the matrix material, making NAA a reliable and effective analytical tool. While not as precise as isotopedilution mass spectrometry, NAA was competitive by being sensitive for the analysis of about half of the rare earths (La, Ce, Nd, Sm, Eu, Tb, Yb, Lu). The development of inductively coupled plasma mass spectrometry since the 1980s, together with decommissioning of research reactors and the lack of installation of new ones in Europe and North America has led to the rapid decline of NAA.

Estimation of the rotamerization constants of different conformations of N-acetylalanine: a theoretical and matrix-isolation FT-IR study.

PubMed

Boeckx, Bram; Maes, Guido

2012-02-01

The conformational landscape of N-acetylalanine has been investigated by a theoretical and matrix-isolation FT-IR study. Optimizations of N-acetylalanine structures has been conducted at successive higher levels of theory HF/3-21G, DFT(B3LYP)/6-31++G** and MP2/6-31++G**. This resulted in three stable conformations. Among these, one conformation contains an intramolecular H-bond. The vibrational properties of these conformations were calculated and used to identify the conformations in a cryogenic argon matrix. The intensities of some bands assigned to a particular conformation were used to estimate the rotamerization constants K(r12) and K(r13) for the equilibria NAA1 NAA2 and NAA1 NAA3, respectively. The obtained experimental values were in agreement with the theoretical predictions. Copyright © 2011 Elsevier B.V. All rights reserved.

Synthesis of zeolites Na-A and Na-X from tablet compressed and calcinated coal fly ash

NASA Astrophysics Data System (ADS)

Hu, Tao; Gao, Wenyan; Liu, Xin; Zhang, Yifu; Meng, Changgong

2017-10-01

Zeolites Na-A and Na-X are important synthetic zeolites widely used for separation and adsorption in industry. It is of great significance to develop energy-efficient routines that can synthesize zeolites Na-A and Na-X from low-cost raw materials. Coal fly ash (CFA) is the major residue from the combustion of coal and biomass containing more than 85% SiO2 and Al2O3, which can readily replace the conventionally used sodium silicate and aluminate for zeolite synthesis. We used Na2CO3 to replace the expensive NaOH used for the calcination of CFA and showed that tablet compression can enhance the contact with Na2CO3 for the activation of CFA through calcination for the synthesis of zeolites Na-A and Na-X under mild conditions. We optimized the control variables for zeolite synthesis and showed that phase-pure zeolite Na-A can be synthesized with CFA at reactant molar ratio, hydrothermal reaction temperature and reaction time of 1.3Na2O: 0.6Al2O3: 1SiO2: 38H2O at 80°C for 6 h, respectively, while phase-pure zeolite Na-X can be synthesized at 2.2Na2O: 0.2Al2O3: 1SiO2: 88H2O at 100°C for 8 h, respectively. The composition, morphology, specific surface area, vibration spectrum and thermogravimetry of synthesized Na-A and Na-X were further characterized.

Blood harmane is correlated with cerebellar metabolism in essential tremor: a pilot study.

PubMed

Louis, Elan D; Zheng, Wei; Mao, Xiangling; Shungu, Dikoma C

2007-08-07

On proton magnetic resonance spectroscopic imaging ((1)H MRSI), there is a decrease in cerebellar N-acetylaspartate/total creatine (NAA/tCr) in essential tremor (ET), signifying cerebellar neuronal dysfunction or degeneration. Harmane, which is present in the human diet, is a potent tremor-producing neurotoxin. Blood harmane concentrations seem to be elevated in ET. To assess in patients with ET whether blood harmane concentration is correlated with cerebellar NAA/tCR, a neuroimaging measure of neuronal dysfunction or degeneration. Twelve patients with ET underwent (1)H MRSI. The major neuroanatomic structure of interest was the cerebellar cortex. Secondary regions were the central cerebellar white matter, cerebellar vermis, thalamus, and basal ganglia. Blood concentrations of harmane and another neurotoxin, lead, were also assessed. Mean +/- SD cerebellar NAA/tCR was 1.52 +/- 0.41. In a linear regression model that adjusted for age and gender, log blood harmane concentration was a predictor of cerebellar NAA/tCR (beta = -0.41, p = 0.009); every 1 g(-10)/mL unit increase in log blood harmane concentration was associated with a 0.41 unit decrease in cerebellar NAA/tCR. The association between blood harmane concentration and brain NAA/tCR only occurred in the cerebellar cortex; it was not observed in secondary brain regions of interest. Furthermore, the association was specific to harmane and not another neurotoxin, lead. This study provides additional support for the emerging link between harmane, a neurotoxin, and ET. Further studies are warranted to address whether cerebellar harmane concentrations are associated with cerebellar pathology in postmortem studies of the ET brain.

Realisation and advanced engineering of true optical rugate filters based on nanoporous anodic alumina by sinusoidal pulse anodisation.

PubMed

Santos, Abel; Yoo, Jeong Ha; Rohatgi, Charu Vashisth; Kumeria, Tushar; Wang, Ye; Losic, Dusan

2016-01-21

This study is the first realisation of true optical rugate filters (RFs) based on nanoporous anodic alumina (NAA) by sinusoidal waves. An innovative and rationally designed sinusoidal pulse anodisation (SPA) approach in galvanostatic mode is used with the aim of engineering the effective medium of NAA in a sinusoidal fashion. A precise control over the different anodisation parameters (i.e. anodisation period, anodisation amplitude, anodisation offset, number of pulses, anodisation temperature and pore widening time) makes it possible to engineer the characteristic reflection peaks and interferometric colours of NAA-RFs, which can be finely tuned across the UV-visible-NIR spectrum. The effect of the aforementioned anodisation parameters on the photonic properties of NAA-RFs (i.e. characteristic reflection peaks and interferometric colours) is systematically assessed in order to establish for the first time a comprehensive rationale towards NAA-RFs with fully controllable photonic properties. The experimental results are correlated with a theoretical model (Looyenga-Landau-Lifshitz - LLL), demonstrating that the effective medium of these photonic nanostructures can be precisely described by the effective medium approximation. NAA-RFs are also demonstrated as chemically selective photonic platforms combined with reflectometric interference spectroscopy (RIfS). The resulting optical sensing system is used to assess the reversible binding affinity between a model drug (i.e. indomethacin) and human serum albumin (HSA) in real-time. Our results demonstrate that this system can be used to determine the overall pharmacokinetic profile of drugs, which is a critical aspect to be considered for the implementation of efficient medical therapies.

Surface modification of nanoporous anodic alumina photonic crystals for photocatalytic applications

NASA Astrophysics Data System (ADS)

Lim, Siew Yee; Law, Cheryl Suwen; Santos, Abel

2018-01-01

Herein, we report on the development of a rationally designed composite photocatalyst material by combining nanoporous anodic alumina-rugate filters (NAA-RFs) with photo-active layers of titanium dioxide (TiO2). NAA-RFs are synthesised by sinusoidal pulse anodisation and subsequently functionalised with TiO2 by sol-gel method to provide the photonic structures with photocatalytic properties. We demonstrate that the characteristic photonic stopband (PSB) of the surface-modified NAA-RFs can be precisely tuned across the UV-visible-NIR spectrum to enhance the photon-toelectron conversion of TiO2 by `slow photon effect'. We systematically investigate the effect of the anodisation parameters (i.e. anodisation period and pore widening time) on the position of the PSB of NAA-RFs as well as the photocatalytic performances displayed by these photonic crystal structures. When the edges of the PSB of surfacemodified NAA-RFs are positioned closely to the absorption peak of the model organic dye (i.e. methyl orange - MO), the photocatalytic performance of the system to degrade these molecules is enhanced under simulated solar light irradiation due to slow photon effect. Our investigation also reveals that the photocatalytic activity of surface-modified NAA-RFs is independent of slow photon effect and enhances with increasing period length (i.e. increasing anodisation period) of the photonic structures when there is no overlap between the PSB and the absorption peak of MO. This study therefore provides a rationale towards the photocatalytic enhancement of photonic crystals by a rational design of the PSB, creating new opportunities for the future development of high-performance photocatalysts.

Carnation (Dianthus caryophylus L.).

PubMed

Nontaswatsri, Chalermsri; Fukai, Seiichi

2006-01-01

Carnation is a valuable crop for the cut flower industry and demand for new and improved varieties is growing. However, genetic transformation of carnations is currently limited because of a lack of efficient routine technique. In this chapter, we present an easy and effective protocol for gene transfer to carnation node explants and subsequent adventitious shoot regeneration. For high-adventitious shoot regeneration, node explants from first to third node of 5- to 8-cm long shoots were cultured on Murashige and Skoog (MS) medium, containing 1.0 mg/Lthidiazuron (TDZ), 0.1 mg/L alpha-napthalenoacetic acid (NAA), 20 g/L sucrose, and 2 g/L Gellan gum for 10 d. Then the explants were cut into 8 radial segments and subcultured onto MS medium, containing 1.0 mg/L BA, 0.1 mg/L NAA, 20 g/L sucrose and 2 g/L Gellan Gum. For effective genetic transformation, 3- to 5-d precultured node explants were submerged in an Agrobacerium suspension for 10 min, then cocultivated on filter paper soaked with water and 50 microM acetosyringone (AS). After cocultivation, the explants were cut into eight radial segments and subcultured onto selection medium until transformed shoots regenerated from the explants.

77 FR 6016 - Approval and Promulgation of Implementation Plans; State of Tennessee: Prevention of Significant...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-07

..., and extreme nonattainment (NAA) classifications) and significant emission rates for the 8-hour ozone..., serious, severe, and extreme ozone NAA. \\4\\ On July 18, 1997, EPA promulgated a revised 8-hour ozone NAAQS...

A Sensor Based on LiCl/NaA Zeolite Composites for Effective Humidity Sensing.

PubMed

Zhang, Ying; Xiang, Hongyu; Sun, Liang; Xie, Qiuhong; Liu, Man; Chen, Yu; Ruan, Shengping

2018-03-01

LiCl/NaA zeolite composites were successfully prepared by doping 1 wt%, 2 wt%, 5 wt%, and 8 wt% of LiCl into NaA zeolite. The humidity sensing properties of LiCl/NaA composites were investigated among 11% 95% relative humidity (RH). The LiCl/NaA composites exhibited better humidity sensing properties than pure NaA zeolite. The sensor made by 2 wt% Li-doped NaA zeolite possesses the best linearly in the whole RH. These results demonstrate that the LiCl/NaA composites have the potential application in humidity sensing.

Simultaneous measurement of Aspartate, NAA, and NAAG using HERMES spectral editing at 3 Tesla.

PubMed

Chan, Kimberly L; Saleh, Muhammad G; Oeltzschner, Georg; Barker, Peter B; Edden, Richard A E

2017-07-15

It has previously been shown that the HERMES method ('Hadamard Encoding and Reconstruction of MEGA-Edited Spectroscopy') can be used to simultaneously edit pairs of metabolites (such as N-acetyl-aspartate (NAA) and N-acetyl aspartyl glutamate (NAAG), or glutathione and GABA). In this study, HERMES is extended for the simultaneous editing of three overlapping signals, and illustrated for the example of NAA, NAAG and Aspartate (Asp). Density-matrix simulations were performed in order to optimize the HERMES sequence. The method was tested in NAA and Asp phantoms, and applied to the centrum semiovale of the nine healthy control subjects that were scanned at 3T. Both simulations and phantom experiments showed similar metabolite multiplet patterns with good segregation of all three metabolites. In vivo measurements show consistent relative signal intensities and multiplet patterns with concentrations in agreement with literature values. Simulations indicate co-editing of glutathione, glutamine, and glutamate, but their signals do not significantly overlap with the detected aspartyl resonances. This study demonstrates that a four-step Hadamard-encoded editing scheme can be used to simultaneously edit three otherwise overlapping metabolites, and can measure NAA, NAAG, and Asp in vivo in the brain at 3T with minimal crosstalk. Copyright © 2017 Elsevier Inc. All rights reserved.

Removal of Pb(II) from wastewater using Al2O3-NaA zeolite composite hollow fiber membranes synthesized from solid waste coal fly ash.

PubMed

Zhu, Li; Ji, Jiayou; Wang, Shulin; Xu, Chenxi; Yang, Kun; Xu, Man

2018-09-01

Al 2 O 3 -NaA zeolite composite hollow fiber membranes were successfully fabricated via hydrothermal synthesis by using industrial solid waste coal fly ash and porous Al 2 O 3 hollow fiber supports. The as-synthesized Al 2 O 3 -NaA zeolite composite hollow fiber membranes were then characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The hollow fiber membranes were used to remove lead ions (Pb(II), 50 mg L -1 ) from synthetic wastewater with a removal efficiency of 99.9% at 0.1 MPa after 12 h of filtration. This study showed that the Al 2 O 3 -NaA zeolite composite hollow fiber membranes (the pore size of the membrane was about 0.41 nm in diameter) synthesized from coal fly ash could be efficiently used for treating low concentration Pb(II) wastewater. It recycled solid waste coal fly ash not only to solve its environment problems, but also can produce high-value Al 2 O 3 -NaA zeolite composite hollow fiber membranes for separation application in treating wastewater containing Pb(II). Copyright © 2018 Elsevier Ltd. All rights reserved.

Dorsolateral prefrontal cortex N-acetylaspartate/total creatine (NAA/tCr) loss in male recreational cannabis users.

PubMed

Hermann, Derik; Sartorius, Alexander; Welzel, Helga; Walter, Sigrid; Skopp, Gisela; Ende, Gabriele; Mann, Karl

2007-06-01

Cannabinoids present neurotoxic and neuroprotective properties in in vitro studies, inconsistent alterations in human neuroimaging studies, neuropsychological deficits, and an increased risk for psychotic episodes. Proton magnetic resonance spectroscopy ((1)H-MRS), neuropsychological testing, and hair analysis for cannabinoids was performed in 13 male nontreatment-seeking recreational cannabis users and 13 male control subjects. A significantly diminished N-acetylaspartate/total creatine (NAA/tCr) ratio in the dorsolateral prefrontal cortex (DLPFC) was observed in cannabis users (p = .0003). The NAA/tCr in the putamen/globus pallidum region correlated significantly with cannabidiol (R(2) = .66, p = .004). Results of the Wisconsin Card Sorting test, Trail making Test, and D2 test for attention were influenced by cannabinoids. Chronic recreational cannabis use is associated with an indication of diminished neuronal and axonal integrity in the DLPFC in this study. As chronic cannabis use is a risk factor for psychosis, these results are interesting because diminished NAA/tCr ratios in the DLPFC and neuropsychological deficits were also reported in schizophrenia. The strong positive correlation of NAA/tCr and cannabidiol in the putamen/globus pallidum is in line with neuroprotective properties of cannabidiol, which were also observed in in vitro model studies of Parkinson's disease.

Correlation analysis of expressions of PTEN and p53 with the value obtained by magnetic resonance spectroscopy and apparent diffusion coefficient in the tumor and the tumor-adjacent area in magnetic resonance imaging for glioblastoma.

PubMed

Li, Yunyun; Ji, Feng; Jiang, Yuzhi; Zhao, Ting; Xu, Chongfu

2018-01-01

To explore the correlation of the expression levels of phosphate and tension homology deleted on chromosome ten (PTEN) and p53 of glioblastoma multiforme (GBM) with the value obtained by magnetic resonance spectroscopy (MRS) and apparent diffusion coefficient (ADC) in the tumor and the tumor-adjacent area in magnetic resonance imaging (MRI). A total of 38 patients were operated for GBM. All the patients had received diffusion-weighted imaging (DWI) and MRS prior to surgery. ADC of water molecules and values of metabolite indexes of MRS, including n-acetyl aspartate (NAA), choline (Cho) and creatine (Cr), were recorded, and the ratios of Cho/NAA, Cho/Cr and NAA/Cr were calculated. Hematoxylin-eosin (H&E) staining was done to examine the morphology of tumor and of tumor-adjacent tissues; immunohistochemistry (IHC) was performed to examine the expressions of PTEN and p53 in the tumor and the tumor-adjacent area. Finally, the correlations of the expressions of PTEN and p53 with ADC, Cho/NAA, Cho/Cr and NAA/Cr of the tumor and the tumor-adjacent area were analyzed. H&E staining showed that GBM tissues had disordered morphology, different sizes of cells, large cell nuclei and significant cell heterogeneity. IHC indicated that the expression level of p53 protein in the tumor was significantly higher than in the tumor-adjacent tissues (p<0.05). The expression level of PTEN protein was high in the tumor-adjacent tissues, but significantly deficient in the tumor. DWI showed that the signal of DWI in the tumor was significantly increased, but ADC was decreased compared with the tumor-adjacent area. MRS indicated that the wave band of Cho in the tumor was significantly increased, NAA was significantly lowered, and Cr section was decreased compared with the tumor-adjacent area, while NAA/Cr in the tumor was significantly decreased compared with the tumoradjacent area (p<0.05). Correlation analysis indicated that PTEN levels in the tumor and the tumor-adjacent area were positively correlated with ADC in the corresponding area, while p53 in the tumor and the tumor-adjacent area was negatively correlated with ADC in the corresponding area. Cho/NAA and Cho/Cr in the tumor were positively correlated with p53 in the tumor, but negatively correlated with PTEN in the tumor. However, NAA/Cr of the tumor was irrelevant to the levels of PTEN and p53. The test results of DWI and MRS of patients with GBM can accurately reflect the inactivation or mutation of PTEN and p53.

High gamma-aminobutyric acid level in cortical tubers in epileptic infants with tuberous sclerosis complex measured with the MEGA-editing J-difference method and a three-Tesla clinical MRI Instrument.

PubMed

Taki, Masako Minato; Harada, Masafumi; Mori, Kenji; Kubo, Hitoshi; Nose, Ayumi; Matsuda, Tsuyoshi; Nishitani, Hiromu

2009-10-01

The purpose of this study was to estimate the gamma-aminobutyric acid (GABA) and glutamate plus glutamine (Glx) concentrations in the cortical tubers of patients with tuberous sclerosis complex (TSC) using the MEGA-editing J-difference method and a stimulated echo-acquisition mode with a short echo time, and to determine which abnormality was more dominant between GABA and Glx in patients with TSC with epilepsy. This study included six patients with TSC (mean age, 4.3 years) and seven control subjects (mean age, 4.8 years). Measurements were obtained with a three-Tesla apparatus and postprocessing was conducted with an LCModel. The GABA level in the cortical gray matter (cgGABA) was calculated as a result of segmentation in voxels and from the literature values for gray and white matter ratios for GABA. Increased GABA and myo-inositol (mI) concentrations and a decreased N-acetyl aspartate (NAA) concentration were observed in the cortical tubers. The cgGABA level, and cgGABA/NAA and cgGABA/Glx ratios were also higher in patients with TSC than in control subjects. No significant difference was found in Glx concentration between patients with TSC and control subjects. Although the number of patients with TSC in this study was small, the increase in GABA and no significant change in Glx were consistent with previous neurochemical studies and support the hypothesis that brain GABA plays a key role in the pathophysiology of epilepsy during the process of neuronal development.

Rapamycin ameliorates brain metabolites alterations after transient focal ischemia in rats.

PubMed

Chauhan, Anjali; Sharma, Uma; Jagannathan, Naranamangalam R; Gupta, Yogendra Kumar

2015-06-15

Rapamycin has been shown to protect against middle cerebral artery occlusion (MCAo) induced ischemic injury. In this study, the neuroprotective effect of rapamycin on the metabolic changes induced by MCAo was evaluated using nuclear magnetic resonance (NMR) spectroscopy of brain tissues. MCAo in rats was induced by insertion of nylon filament. One hour after ischemia, rapamycin (250 µg/kg, i.p.) in dimethyl sulfoxide was administered. Reperfusion was done 2h after ischemia. Twenty-four hours after ischemia phospholipase A2 (PLA2) levels and metabolic changes were assessed. Perchloric acid extraction was performed on the brain of all animals (n=7; sham, vehicle; DMSO and rapamycin 250 µg/kg) and the various brain metabolites were assessed by NMR spectroscopy. In all 44 metabolites were assigned in the proton NMR spectrum of rat brain tissues. In the vehicle group, we observed increased lactate levels and decreased levels of glutamate/glutamine, choline containing compounds, creatine/phosphocreatine (Cr/PCr), taurine, myo-inositol, γ-amino butryic acid (GABA), N-aspartyl aspartate (NAA), purine and pyrimidine metabolites. In rapamycin treated rats, there was increase in the levels of choline containing compounds, NAA, myo-inositol, glutamate/glutamine, GABA, Cr/PCr and taurine as compared to those of vehicle control (P<0.05). Rapamycin treatment reduced PLA2 levels as compared to vehicle group (P<0.05). Our findings indicated that rapamycin reduced the increased PLA2 levels and altered brain metabolites after MCAo. These protective effects might be attributed to its effect on cell membrane metabolism; glutamate induced toxicity and calcium homeostasis in stroke. Copyright © 2015 Elsevier B.V. All rights reserved.

Native American ancestry, lung function, and COPD in Costa Ricans.

PubMed

Chen, Wei; Brehm, John M; Boutaoui, Nadia; Soto-Quiros, Manuel; Avila, Lydiana; Celli, Bartolome R; Bruse, Shannon; Tesfaigzi, Yohannes; Celedón, Juan C

2014-04-01

Whether Native American ancestry (NAA) is associated with COPD or lung function in a racially admixed Hispanic population is unknown. We recruited 578 Costa Ricans with and without COPD into a hybrid case-control/family-based cohort, including 316 members of families of index case subjects. All participants completed questionnaires and spirometry and gave a blood sample for DNA extraction. Genome-wide genotyping was conducted with the Illumina Human610-Quad and HumanOmniExpress BeadChip kits (Illumina Inc), and individual ancestral proportions were estimated from these genotypic data and reference panels. For unrelated individuals, linear or logistic regression was used for the analysis of NAA and COPD (GOLD [Global Initiative for Chronic Obstructive Lung Disease] stage II or greater) or lung function. For extended families, linear mixed models and generalized estimating equations were used for the analysis. All models were adjusted for age, sex, educational level, and smoking behavior; models for FEV1 were also adjusted for height. The average proportion of European, Native American, and African ancestry among participants was 62%, 35%, and 3%, respectively. After adjustment for current smoking and other covariates, NAA was inversely associated with COPD (OR per 10% increment, 0.55; 95% CI, 0.41-0.75) but positively associated with FEV1, FVC, and FEV1/FVC. After additional adjustment for pack-years of smoking, the association between NAA and COPD or lung function measures was slightly attenuated. We found that about 31% of the estimated effect of NAA on COPD is mediated by pack-years of smoking. NAA is inversely associated with COPD but positively associated with FEV1 or FVC in Costa Ricans. Ancestral effects on smoking behavior partly explain the findings for COPD but not for FEV1 or FVC.

Native American Ancestry, Lung Function, and COPD in Costa Ricans

PubMed Central

Chen, Wei; Brehm, John M.; Boutaoui, Nadia; Soto-Quiros, Manuel; Avila, Lydiana; Celli, Bartolome R.; Bruse, Shannon; Tesfaigzi, Yohannes

2014-01-01

Background: Whether Native American ancestry (NAA) is associated with COPD or lung function in a racially admixed Hispanic population is unknown. Methods: We recruited 578 Costa Ricans with and without COPD into a hybrid case-control/family-based cohort, including 316 members of families of index case subjects. All participants completed questionnaires and spirometry and gave a blood sample for DNA extraction. Genome-wide genotyping was conducted with the Illumina Human610-Quad and HumanOmniExpress BeadChip kits (Illumina Inc), and individual ancestral proportions were estimated from these genotypic data and reference panels. For unrelated individuals, linear or logistic regression was used for the analysis of NAA and COPD (GOLD [Global Initiative for Chronic Obstructive Lung Disease] stage II or greater) or lung function. For extended families, linear mixed models and generalized estimating equations were used for the analysis. All models were adjusted for age, sex, educational level, and smoking behavior; models for FEV1 were also adjusted for height. Results: The average proportion of European, Native American, and African ancestry among participants was 62%, 35%, and 3%, respectively. After adjustment for current smoking and other covariates, NAA was inversely associated with COPD (OR per 10% increment, 0.55; 95% CI, 0.41-0.75) but positively associated with FEV1, FVC, and FEV1/FVC. After additional adjustment for pack-years of smoking, the association between NAA and COPD or lung function measures was slightly attenuated. We found that about 31% of the estimated effect of NAA on COPD is mediated by pack-years of smoking. Conclusions: NAA is inversely associated with COPD but positively associated with FEV1 or FVC in Costa Ricans. Ancestral effects on smoking behavior partly explain the findings for COPD but not for FEV1 or FVC. PMID:24306962

The prevalence and impact of antimicrobial allergies and adverse drug reactions at an Australian tertiary centre.

PubMed

Trubiano, Jason A; Cairns, Kelly A; Evans, Jacqui A; Ding, Amally; Nguyen, Tuan; Dooley, Michael J; Cheng, Allen C

2015-12-16

The prevalence and impact of antimicrobial "allergy" labels and Adverse Drug Reactions (ADRs) on antibiotic usage and antimicrobial stewardship initiatives is ill defined. We sought to examine the rate of antimicrobial "allergy labels" at our tertiary referral centre and impacts on antimicrobial usage and appropriateness. Two inpatient antimicrobial prevalence surveys were conducted over a 1-week period in November 2013 and 2014 as part of the prospective National Antimicrobial Prescribing Survey (NAPS). Post survey, patients recorded in the NAPS database were assigned to two groups based upon recorded antimicrobial "allergy label" and ADR: (i) Antimicrobial Allergy/ADR (AA) or (ii) No Antimicrobial Allergy/ADR (NAA). Antimicrobial usage and antimicrobial appropriateness were compared between AA and NAA groups. From 509 identified patients the prevalence of an antimicrobial allergy or ADR was 25 %. The prevalence of "allergy labels"/ADR was 10 % (51/509) for penicillin V/G, 5 % (24/509) cephalosporins, 4 % (22/509) trimethroprim-sulfamethoxazole and 3 % (17/509) aminopenicillins. One thousand and seventy antimicrobials were prescribed during the study periods, the median antimicrobial duration was longer in the AA versus NAA group (6 days vs. 4 days; p = 0.018), and proportion of inappropriate antimicrobial prescribing higher in the AA group compared with NAA (29 %; 35/120 vs. 23 %; 86/367, p = 0.22). Oral antimicrobial administration was higher in the NAA than AA group (60 %; 177/297 vs. 46 %; 356/793, p = 0.0001). The proportion of patients that received a β-lactam was lower in the AA versus NAA group (60 % vs. 79 %, p = 0.0001). In an Australian tertiary referral centre an antimicrobial "allergy" or ADR label was found to significantly impacted on rate of oral antimicrobial administration, beta-lactam usage, antimicrobial duration and antimicrobial appropriateness.

Reduction of N-acetylaspartate in the medial prefrontal cortex correlated with symptom severity in obsessive-compulsive disorder: meta-analyses of 1H-MRS studies

PubMed Central

Aoki, Yuta; Aoki, Ai; Suwa, Hiroshi

2012-01-01

Structural and functional neuroimaging findings suggest that disturbance of the cortico–striato–thalamo–cortical (CSTC) circuits may underlie obsessive-compulsive disorder (OCD). However, some studies with 1H-magnetic resonance spectroscopy (1H-MRS) reported altered level of N-acetylaspartate (NAA), they yielded inconsistency in direction and location of abnormality within CSTC circuits. We conducted a comprehensive literature search and a meta-analysis of 1H-MRS studies in OCD. Seventeen met the inclusion criteria for a meta-analysis. Data were separated by frontal cortex region: medial prefrontal cortex (mPFC), dorsolateral prefrontal cortex, orbitofrontal cortex, basal ganglia and thalamus. The mean and s.d. of the NAA measure were calculated for each region. A random effects model integrating 16 separate datasets with 225 OCD patients and 233 healthy comparison subjects demonstrated that OCD patients exhibit decreased NAA levels in the frontal cortex (P=0.025), but no significant changes in the basal ganglia (P=0.770) or thalamus (P=0.466). Sensitivity analysis in an anatomically specified subgroup consisting of datasets examining the mPFC demonstrated marginally significant reduction of NAA (P=0.061). Meta-regression revealed that NAA reduction in the mPFC was positively correlated with symptom severity measured by Yale–Brown Obsessive Compulsive Scale (P=0.011). The specific reduction of NAA in the mPFC and significant relationship between neurochemical alteration in the mPFC and symptom severity indicate that the mPFC is one of the brain regions that directly related to abnormal behavior in the pathophysiology of OCD. The current meta-analysis indicates that cortices and sub-cortices contribute in different ways to the etiology of OCD. PMID:22892718

Is NAA reduction in normal contralateral cerebral tissue in stroke patients dependent on underlying risk factors?

PubMed

Walker, P M; Ben Salem, D; Giroud, M; Brunotte, F

2006-05-01

This retrospective study investigated the dependence of N-acetyl aspartate (NAA) ratios on risk factors for cerebral vasculopathy such as sex, age, hypertension, diabetes mellitus, carotid stenosis, and dyslipidaemia, which may have affected brain vessels and induced metabolic brain abnormalities prior to stroke. We hypothesise that in stroke patients metabolic alterations in the apparently normal contralateral brain are dependent on the presence or not of such risk factors. Fifty nine patients (31 male, 28 female: 58.8+/-16.1 years old) with cortical middle cerebral artery (MCA) territory infarction were included. Long echo time chemical shift imaging spectroscopy was carried out on a Siemens 1.5 T Magnetom Vision scanner using a multi-voxel PRESS technique. Metabolite ratios (NAA/choline, NAA/creatine, lactate/choline, etc) were studied using uni- and multivariate analyses with respect to common risk factors. The influence of age, stroke lesion size, and time since stroke was studied using a linear regression approach. Age, sex, and hypertension all appeared to individually influence metabolite ratios, although only hypertension was significant after multivariate analysis. In both basal ganglia and periventricular white matter regions in apparently normal contralateral brain, the NAA/choline ratio was significantly lower in hypertensive (1.37+/-0.16 and 1.50+/-0.19, respectively) than in normotensive patients (1.72+/-0.19 and 1.85+/-0.15, respectively). Regarding MCA infarction, contralateral tissue remote from the lesion behaves abnormally in the presence of hypertension, the NAA ratios in hypertensive patients being significantly lower. These data suggest that hypertension may compromise the use of contralateral tissue data as a reference for comparison with ischaemic tissue.

Transcriptional regulation of N-acetylaspartate metabolism in the 5xFAD model of Alzheimer's disease: evidence for neuron-glia communication during energetic crisis.

PubMed

Zaroff, Samantha; Leone, Paola; Markov, Vladimir; Francis, Jeremy S

2015-03-01

N-acetylaspartate (NAA) provides a non-invasive clinical index of neuronal metabolic integrity across the entire neurodegenerative spectrum. While NAA function is not comprehensively defined, reductions in the brain are associated with compromised mitochondrial metabolism and are tightly linked to ATP. We have undertaken an analysis of abnormalities in NAA during early stage pathology in the 5xFAD mouse model of familial Alzheimer's disease and show here that dysregulated expression of the gene encoding for the rate-limiting NAA synthetic enzyme (Nat8L) is associated with deficits in mitochondrial oxidative phosphorylation in this model system. Downreguation of Nat8L is particularly pronounced in the 5xFAD hippocampus, and is preceded by a significant upregulation of oligodendrocytic aspartoacylase (aspa), which encodes for the sole known NAA-catabolizing enzyme in the brain. Reductions in 5xFAD NAA and Nat8L cannot be accounted for by discrepancies in either neuron content or activity of the substrate-providing malate-aspartate shuttle, thereby implicating transcriptional regulation in a coordinated response to pathological energetic crisis. A central role for ASPA in this response is supported by a parallel developmental analysis showing highly significant increases in Nat8L expression in an ASPA-null mouse model during a period of early postnatal development normally punctuated by the transcriptional upregulation of aspa. These results provide preliminary evidence of a signaling mechanism in Alzheimer's disease that involves cross talk between neurons and oligodendrocytes, and suggest that ASPA acts to negatively regulate Nat8L expression. This mechanism is proposed to be a fundamental means by which the brain conserves available substrate during energy crises. Copyright © 2015 Elsevier Inc. All rights reserved.

Cerebral hemodynamics and metabolism in patients with symptomatic occlusion of the internal carotid artery.

PubMed

Rutgers, D R; van Osch, M J P; Kappelle, L J; Mali, W P T M; van der Grond, J

2003-03-01

The goals of this study were to investigate (1) whether the concentrations of choline, creatine, and N-acetyl aspartate (NAA) in cerebral white matter are changed in patients with symptomatic occlusion of the internal carotid artery (ICA) and (2) whether possible changes in metabolite concentration are related to regional cerebral perfusion or cerebral vasoreactivity. In 19 patients (mean+/-SD age, 60+/-9 years), white matter metabolite concentrations were measured with proton MR spectroscopic imaging on average 4+/-2 months after symptoms occurred. In selected voxels, corresponding cerebral blood flow and volume, mean transit time, and time-to-bolus peak were determined with dynamic susceptibility contrast MRI. Cerebral CO2 reactivity was determined with transcranial Doppler sonography. No significant changes in choline and creatine concentrations were observed. NAA concentration was significantly reduced in the hemisphere on the side of the symptomatic ICA (9.1+/-1.7 mmol/L) compared with the contralateral hemisphere (10.5+/-1.7 mmol/L, P<0.005) and control subjects (10.5+/-0.9 mmol/L, P<0.01). Although no significant interhemispheric difference in NAA concentration was found in patients who presented with retinal ischemia, patients with cerebral ischemia had a significantly lower NAA concentration in the symptomatic hemisphere (9.0+/-1.7 mmol/L) compared with the asymptomatic hemisphere (10.4+/-1.6 mmol/L, P<0.05). In all patients, NAA concentration was not significantly correlated with quantitative cerebral perfusion parameters or CO2 reactivity. Patients with symptomatic ICA occlusion may show chronic neuronal damage in cerebral white matter as evidenced by reduced NAA concentration. This seems to be related to previous symptomatology rather than to the cerebral hemodynamic status in a chronic stage.

NAA TECHNIQUE FOR CLINICAL INVESTIGATION OF MICE IMMUNIZED WITH BOTHROP VENOM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zamboni, C. B.; Aguiar, R. O.; Kovacs, L.

2009-06-03

In the present study Neutron Activation Analysis (NAA) technique was used to determine sodium concentration in whole blood of mice immunized with Bothrops venom. With this value it was possible to perform clinical investigation in this animal model using whole blood.

APPswe/PS1dE9 mice with cortical amyloid pathology show a reduced NAA/Cr ratio without apparent brain atrophy: A MRS and MRI study.

PubMed

Kuhla, Angela; Rühlmann, Claire; Lindner, Tobias; Polei, Stefan; Hadlich, Stefan; Krause, Bernd J; Vollmar, Brigitte; Teipel, Stefan J

2017-01-01

Transgenic animal models of Aβ pathology provide mechanistic insight into some aspects of Alzheimer disease (AD) pathology related to Aβ accumulation. Quantitative neuroimaging is a possible aid to improve translation of mechanistic findings in transgenic models to human end phenotypes of brain morphology or function. Therefore, we combined MRI-based morphometry, MRS-based NAA-assessment and quantitative histology of neurons and amyloid plaque load in the APPswe/PS1dE9 mouse model to determine the interrelationship between morphological changes, changes in neuron numbers and amyloid plaque load with reductions of NAA levels as marker of neuronal functional viability. The APPswe/PS1dE9 mouse showed an increase of Aβ plaques, loss of neurons and an impairment of NAA/Cr ratio, which however was not accompanied with brain atrophy. As brain atrophy is one main characteristic in human AD, conclusions from murine to human AD pathology should be drawn with caution.

Reduced N-acetylaspartate to creatine ratio in the posterior cingulate correlates with cognition in Alzheimer's disease following four months of rivastigmine treatment.

PubMed

Penner, Jacob; Wells, Jennie L; Borrie, Michael J; Woolmore-Goodwin, Sarah M; Bartha, Robert

2015-01-01

To determine whether 4 months of rivastigmine treatment would result in metabolic changes and whether metabolic changes correlate with changes in cognition in people with Alzheimer's disease (AD). Magnetic resonance spectra were acquired from the posterior cingulate cortex of subjects with AD at 3 T. Magnetic resonance imaging scans and cognitive tests were performed before and 4 months after the beginning of the treatment. Metabolite concentrations were quantified and used to calculate the metabolite ratios. On average, the N-acetylaspartate/creatine (NAA/Cr) ratio decreased by 12.7% following 4 months of rivastigmine treatment, but changes in the NAA/Cr ratio correlated positively with changes in Mini-Mental State Examination scores. This positive correlation between changes in NAA/Cr and changes in cognitive performance suggests that the NAA/Cr ratio could be an objective indicator of a response to rivastigmine treatment. © 2014 S. Karger AG, Basel

N-terminal acetylation modulates Bax targeting to mitochondria.

PubMed

Alves, Sara; Neiri, Leire; Chaves, Susana Rodrigues; Vieira, Selma; Trindade, Dário; Manon, Stephen; Dominguez, Veronica; Pintado, Belen; Jonckheere, Veronique; Van Damme, Petra; Silva, Rui Duarte; Aldabe, Rafael; Côrte-Real, Manuela

2018-02-01

The pro-apoptotic Bax protein is the main effector of mitochondrial permeabilization during apoptosis. Bax is controlled at several levels, including post-translational modifications such as phosphorylation and S-palmitoylation. However, little is known about the contribution of other protein modifications to Bax activity. Here, we used heterologous expression of human Bax in yeast to study the involvement of N-terminal acetylation by yNaa20p (yNatB) on Bax function. We found that human Bax is N-terminal (Nt-)acetylated by yNaa20p and that Nt-acetylation of Bax is essential to maintain Bax in an inactive conformation in the cytosol of yeast and Mouse Embryonic Fibroblast (MEF) cells. Bax accumulates in the mitochondria of yeast naa20Δ and Naa25 -/- MEF cells, but does not promote cytochrome c release, suggesting that an additional step is required for full activation of Bax. Altogether, our results show that Bax N-terminal acetylation by NatB is involved in its mitochondrial targeting. Copyright © 2017 Elsevier Ltd. All rights reserved.

Conventional hydrothermal synthesis of Na-A zeolite from cupola slag and aluminum sludge.

PubMed

Anuwattana, Rewadee; Khummongkol, Pojanie

2009-07-15

Na-A type zeolites were prepared from two industrial wastes: the solid by-product of cupola slag and aluminum sludge from an aluminum plating plant. Two preparation methods using the same starting material compositions were carried out. In the first method, alkaline fusion was introduced, followed by the hydrothermal treatment to obtain sodium aluminosilicate which was then crystallized in NaOH solution under the condition of 90+/-3 degrees C for 1-9h with different H(2)O/SiO2 ratios. The result shows that higher H(2)O/SiO2 ratio increases the rate of crystallization. The largest amount of crystallinity for Na-A was found at 3h. In the second method, alkaline hydrothermal treatment without fusion was carried out in the same condition as the first method. No Na-A zeolite was obtained by this method. The changes of the dissolved amounts of Si(4+) and Al(3+) in 3M NaOH were investigated during the hydrothermal reaction.

Long-term Brain Tissue Monitoring after Semi-brain Irradiation in Rats Using Proton Magnetic Resonance Spectroscopy: A Preliminary Study In vivo

PubMed Central

Chen, Hong; Cheng, Yu-Shu; Zhou, Zheng-Rong

2017-01-01

Background: In head and neck neoplasm survivors treated with brain irradiation, metabolic alterations would occur in the radiation-induced injury area. The mechanism of these metabolic alterations has not been fully understood, while the alternations could be sensitively detected by proton (1H) nuclear magnetic resonance spectroscopy (MRS). In this study, we investigated the metabolic characteristics of radiation-induced brain injury through a long-term follow-up after radiation treatment using MRS in vivo. Methods: A total of 12 adult Sprague-Dawley rats received a single dose of 30 Gy radiation treatment to semi-brain (field size: 1.0 cm × 2.0 cm; anterior limit: binocular posterior inner canthus connection; posterior limit: external acoustic meatus connection; internal limit: sagittal suture). Conventional magnetic resonance imaging and single-voxel 1H-MRS were performed at different time points (in month 0 before irradiation as well as in the 1st, 3rd, 5th, 7th, and 9th months after irradiation) to investigate the alternations in irradiation field. N-acetylaspartate/choline (NAA/Cho), NAA/creatinine (Cr), and Cho/Cr ratios were measured in the bilateral hippocampus and quantitatively analyzed with a repeated-measures mixed-effects model and multiple comparison test. Results: Significant changes in the ratios of NAA/Cho (F = 57.37, Pg < 0.001), NAA/Cr (F = 54.49, Pg < 0.001), and Cho/Cr (F = 9.78, Pg = 0.005) between the hippocampus region of the irradiated semi-brain and the contralateral semi-brain were observed. There were significant differences in NAA/Cho (F = 9.17, Pt < 0.001) and NAA/Cr (F = 13.04, Pt < 0.001) ratios over time. The tendency of NAA/Cr to change with time showed no significant difference between the irradiated and contralateral sides. Nevertheless, there were significant differences in the Cho/Cr ratio between these two sides. Conclusions: MRS can sensitively detect metabolic alternations. Significant changes of metabolites ratio in the first few months after radiation treatment reflect the metabolic disturbance in the acute and early-delayed stages of radiation-induced brain injuries. PMID:28397726

White matter NAA/Cho and Cho/Cr ratios at MR spectroscopy are predictive of motor outcome in preterm infants.

PubMed

Kendall, Giles S; Melbourne, Andrew; Johnson, Samantha; Price, David; Bainbridge, Alan; Gunny, Roxanna; Huertas-Ceballos, Angela; Cady, Ernest B; Ourselin, Sebastian; Marlow, Neil; Robertson, Nicola J

2014-04-01

To determine (a) whether diffuse white matter injury of prematurity is associated with an increased choline (Cho)-to-creatine (Cr) ratio and a reduced N-acetylaspartate (NAA)-to-Cho ratio and whether these measures can be used as biomarkers of outcome and (b) if changes in peak area metabolite ratios at magnetic resonance (MR) spectroscopy are associated with changes in T2 and fractional anisotropy (FA) at MR imaging. The local ethics committee approved this study, and informed parental consent was obtained for each infant. At term-equivalent age, 43 infants born at less than 32 weeks gestation underwent conventional and quantitative diffusion-tensor and T2-weighted MR imaging. Single-voxel point-resolved proton (hydrogen 1) MR spectroscopy was performed from a 2-cm(3) voxel centered in the posterior periventricular white matter. Outcome was evaluated by using Bayley scales at a corrected age of 1 year. Associations were investigated with Pearson product moment or Spearman rank order correlation. Differences in ratios in infants with and infants without impairment were tested by using t tests. NAA/Cho and Cho/Cr ratios correlated with the scaled gross motor score and the composite motor score, independent of gestational age (P < .05). FA at diffusion-tensor MR imaging and T2 at MR imaging correlated with the NAA/Cho ratio (P < .05 for both) but not with the Cho/Cr ratio. Infants with motor scores of less than 85 (impaired) had an increased Cho/Cr ratio (P < .03) and a reduced NAA/Cho ratio (P < .01) compared to those without impairment. A combination of increased Cho/Cr ratio and decreased NAA/Cho ratio predicted impaired motor outcome at a corrected age of 1 year with a sensitivity of 0.80 (95% confidence interval [CI]: 0.57, 0.94) and a specificity of 0.80 (95% CI: 0.66, 0.88). The combination of Cho/Cr and NAA/Cho ratios measured in the posterior periventricular white matter at term-equivalent age is predictive of motor outcome at 1 year in infants born at less than 32 weeks gestation. RSNA, 2013

Role of Natural IgM Autoantibodies (IgM-NAA) and IgM Anti-Leukocyte Antibodies (IgM-ALA) in Regulating Inflammation.

PubMed

Lobo, Peter I

2017-01-01

Natural IgM autoantibodies (IgM-NAA) are rapidly produced to inhibit pathogens and abrogate inflammation mediated by invading microorganisms and host neoantigens. IgM-NAA achieve this difficult task by being polyreactive with low binding affinity but with high avidity, characteristics that allow these antibodies to bind antigenic determinants shared by pathogens and neoantigens. Hence the same clones of natural IgM can bind and mask host neoantigens as well as inhibit microorganisms. In addition, IgM-NAA regulate the inflammatory response via mechanisms involving binding of IgM to apoptotic cells to enhance their removal and binding of IgM to live leukocytes to regulate their function. Secondly, we review how natural IgM prevents autoimmune disorders arising from pathogenic IgG autoantibodies as well as by autoreactive B and T cells that have escaped tolerance mechanisms. Thirdly, using IgM knockout mice, we show that regulatory B and T cells require IgM to effectively regulate inflammation mediated by innate, adaptive and autoimmune mechanisms. It is therefore not surprising why the host positively selects such autoreactive B1 cells that generate protective IgM-NAA, which are also evolutionarily conserved. Fourthly, we show that IgM anti-leukocyte autoantibodies (IgM-ALA) levels and their repertoire can vary in normal humans and disease states and this variation may partly explain the observed differences in the inflammatory response after infection, ischemic injury or after a transplant. Finally we also show how protective IgM-NAA can be rendered pathogenic under non-physiological conditions. IgM-NAA have therapeutic potential. Polyclonal IgM infusions can be used to abrogate ongoing inflammation. Additionally, inflammation arising after ischemic kidney injury, e.g., during high-risk elective cardiac surgery or after allograft transplantation, can be prevented by pre-emptively infusing polyclonal IgM, or DC pretreated ex vivo with IgM, or by increasing in vivo IgM with a vaccine approach. Cell therapy with IgM pretreated cells, is appealing as less IgM will be required.

Post-WBRT cognitive impairment and hippocampal neuronal depletion measured by in vivo metabolic MR spectroscopy: Results of prospective investigational study.

PubMed

Pospisil, Petr; Kazda, Tomas; Hynkova, Ludmila; Bulik, Martin; Dobiaskova, Marie; Burkon, Petr; Laack, Nadia N; Slampa, Pavel; Jancalek, Radim

2017-03-01

The aim of this prospective study is to evaluate post-whole brain radiotherapy (WBRT) changes in hippocampal concentration of N-acetylaspartate (h-tNAA) as a marker of neuronal loss and to correlate those changes to neurocognitive function. Thirty-five patients with brain metastases underwent baseline single slice multi-voxel MR spectroscopy (MRS) examination for measurement of hippocampal h-tNAA together with baseline battery of neurocognitive tests focused on memory (Auditory Verbal Learning Test and Brief Visuospatial Memory Test - Revised) as well as quality of life questionnaires (EORTC QLQ-C30 a EORTC QLQ-BN20). Eighteen patients completed follow-up evaluation four months after standard WBRT (2 laterolateral fields, 10×3.0Gy, 6MV photons) and were included in this analysis. MRS and cognitive examinations were repeated and compared to baseline measurements. Statistically significant decreases in h-tNAA were observed in the right (8.52-7.42mM; -12.9%, 95%CI: -7.6 to -16.4%) as well as in the left hippocampus (8.64-7.60mM; -12%, 95%CI: -7.9 to -16.2%). Statistically significant decline was observed in all AVLT and BVMT-R subtests with exception of AVLT_Recognition. Quality of life declined after WBRT (mean Δ -14.1±20.3 points in transformed 0-100 point scale; p=0.018) with no correlation to changes in hippocampal metabolite concentrations. Moderate positive correlation was observed between left h-tNAA concentration decrease and AVLT_TR decline (r=+0.32; p=0.24) as well as with AVLT_DR (r=+0.33; p=0.22) decline. Changes in right h-tNAA/Cr negatively correlated with AVLT_DR (r=-0.48; p=0.061). No correlation between right hippocampus h-tNAA and memory decline (AVLT) was observed. Our results suggest hippocampal NAA concentrations decline after WBRT and MRS may be a useful biomarker for monitoring neuronal loss after radiotherapy. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

HIV, Vascular and Aging Injuries in the Brain of Clinically Stable HIV-Infected Adults: A 1H MRS Study

PubMed Central

Cysique, Lucette A.; Moffat, Kirsten; Moore, Danielle M.; Lane, Tammy A.; Davies, Nicholas W. S.; Carr, Andrew; Brew, Bruce J.; Rae, Caroline

2013-01-01

Background Cardiovascular disease (CVD) and premature aging have been hypothesized as new risk factors for HIV associated neurocognitive disorders (HAND) in adults with virally-suppressed HIV infection. Moreover, their significance and relation to more classical HAND biomarkers remain unclear. Methods 92 HIV− infected (HIV+) adults stable on combined antiretroviral therapy (cART) and 30 age-comparable HIV-negative (HIV−) subjects underwent 1H Magnetic Resonance Spectroscopy (MRS) of the frontal white matter (targeting HIV, normal aging or CVD-related neurochemical injury), caudate nucleus (targeting HIV neurochemical injury), and posterior cingulate cortex (targeting normal/pathological aging, CVD-related neurochemical changes). All also underwent standard neuropsychological (NP) testing. CVD risk scores were calculated. HIV disease biomarkers were collected and cerebrospinal fluid (CSF) neuroinflammation biomarkers were obtained in 38 HIV+ individuals. Results Relative to HIV− individuals, HIV+ individuals presented mild MRS alterations: in the frontal white matter: lower N-Acetyl-Aspartate (NAA) (p<.04) and higher myo-inositol (mIo) (p<.04); in the caudate: lower NAA (p = .01); and in the posterior cingulate cortex: higher mIo (p<.008– also significant when Holm-Sidak corrected) and higher Choline/NAA (p<.04). Regression models showed that an HIV*age interaction was associated with lower frontal white matter NAA. CVD risk factors were associated with lower posterior cingulate cortex and caudate NAA in both groups. Past acute CVD events in the HIV+ group were associated with increased mIo in the posterior cingulate cortex. HIV duration was associated with lower caudate NAA; greater CNS cART penetration was associated with lower mIo in the posterior cingulate cortex and the degree of immune recovery on cART was associated with higher NAA in the frontal white matter. CSF neopterin was associated with higher mIo in the posterior cingulate cortex and frontal white matter. Conclusions In chronically HIV+ adults with long-term viral suppression, current CVD risk, past CVD and age are independent factors for neuronal injury and inflammation. This suggests a tripartite model of HIV, CVD and age likely driven by chronic inflammation. PMID:23620788

Similarities of biochemical abnormalities between major depressive disorder and bipolar depression: a proton magnetic resonance spectroscopy study.

PubMed

Zhong, Shuming; Wang, Ying; Zhao, Guoxiang; Xiang, Qi; Ling, Xueying; Liu, Sirun; Huang, Li; Jia, Yanbin

2014-10-01

Depression in the context of bipolar disorder (BD) is often misdiagnosed as major depressive disorder (MDD), leading to mistreatments and poor clinical outcomes for many bipolar patients. Previous neuroimaging studies found mixed results on brain structure, and biochemical metabolism of the two disorders. To eliminate the compounding effects of medication, and aging, this study sought to investigate the brain biochemical changes of treatment-naïve, non-late-life patients with MDD and BD in white matter in prefrontal (WMP) lobe, anterior cingulate cortex (ACC) and hippocampus by using proton magnetic resonance spectroscopy ((1)H-MRS). Three groups of participants were recruited: 26 MDD patients, 20 depressed BD patients, and 13 healthy controls. The multi-voxel (1)H-MRS [repetition time (TR)=1000ms; echo-time (TE)=144ms] was used for the measurement of N-acetylaspartate(NAA), choline containg compounds (Cho), and creatine (Cr) in three brain locations: white matter in prefrontal (WMP) lobe, anterior cingulate cortex (ACC), and hippocampus. Two ratios of NAA/Cr and Cho/Cr as a measure of brain biochemical changes were compared among three experimental groups. On the comparison of brain biochemical changes, both MDD patients and BD patients showed many similarities compared to the controls. They both had a significantly lower NAA/Cr ratio in the left WMP lobe. There were no significant differences among three experimental groups for Cho/Cr ratio in the WMP lobe, and for the ratios of NAA/Cr and Cho/Cr in the bilateral ACC and hippocampus. The only difference between MDD and BD patients existed for the NAA/Cr ratio in the right WMP lobe. While MDD patients had a significantly lower NAA/Cr ratio than controls, BD patients showed no such differences. On the comparison of correlation of medical variables and brain biochemical changes, all participants demonstrated no significant correlations. Reduced NAA/Cr ratio at the left WMP lobe indicated the dysfunction of neuronal viability in deep white matter, in both MDD and BD patients who shared similarities of brain biochemical abnormalities, which might imply an overlap in neuropathology of depression. Copyright © 2014 Elsevier B.V. All rights reserved.

Tracing footprints of environmental events in tree ring chemistry using neutron activation analysis

NASA Astrophysics Data System (ADS)

Sahin, Dagistan

The aim of this study is to identify environmental effects on tree-ring chemistry. It is known that industrial pollution, volcanic eruptions, dust storms, acid rain and similar events can cause substantial changes in soil chemistry. Establishing whether a particular group of trees is sensitive to these changes in soil environment and registers them in the elemental chemistry of contemporary growth rings is the over-riding goal of any Dendrochemistry research. In this study, elemental concentrations were measured in tree-ring samples of absolutely dated eleven modern forest trees, grown in the Mediterranean region, Turkey, collected and dated by the Malcolm and Carolyn Wiener Laboratory for Aegean and Near Eastern Dendrochronology laboratory at Cornell University. Correlations between measured elemental concentrations in the tree-ring samples were analyzed using statistical tests to answer two questions. Does the current concentration of a particular element depend on any other element within the tree? And, are there any elements showing correlated abnormal concentration changes across the majority of the trees? Based on the detailed analysis results, the low mobility of sodium and bromine, positive correlations between calcium, zinc and manganese, positive correlations between trace elements lanthanum, samarium, antimony, and gold within tree-rings were recognized. Moreover, zinc, lanthanum, samarium and bromine showed strong, positive correlations among the trees and were identified as possible environmental signature elements. New Dendrochemistry information found in this study would be also useful in explaining tree physiology and elemental chemistry in Pinus nigra species grown in Turkey. Elemental concentrations in tree-ring samples were measured using Neutron Activation Analysis (NAA) at the Pennsylvania State University Radiation Science and Engineering Center (RSEC). Through this study, advanced methodologies for methodological, computational and experimental NAA were developed to ensure an acceptable accuracy and certainty in the elemental concentration measurements in tree-ring samples. Two independent analysis methods of NAA were used; the well known k-zero method and a novel method developed in this study, called the Multi-isotope Iterative Westcott (MIW) method. The MIW method uses reaction rate probabilities for a group of isotopes, which can be calculated by a neutronic simulation or measured by experimentation, and determines the representative values for the neutron flux and neutron flux characterization parameters based on Westcott convention. Elemental concentration calculations for standard reference material and tree-ring samples were then performed using the MIW and k-zero analysis methods of the NAA and the results were cross verified. In the computational part of this study, a detailed burnup coupled neutronic simulation was developed to analyze real-time neutronic changes in a TRIGA Mark III reactor core, in this study, the Penn State Breazeale Reactor (PSBR) core. To the best of the author`s knowledge, this is the first burnup coupled neutronic simulation with realistic time steps and full fuel temperature profile for a TRIGA reactor using Monte Carlo Utility for Reactor Evolutions (MURE) code and Monte Carlo Neutral-Particle Code (MCNP) coupling. High fidelity and flexibility in the simulation was aimed to replicate the real core operation through the day. This approach resulted in an enhanced accuracy in neutronic representation of the PSBR core with respect to previous neutronic simulation models for the PSBR core. An important contribution was made in the NAA experimentation practices employed in Dendrochemistry studies at the RSEC. Automated laboratory control and analysis software for NAA measurements in the RSEC Radionuclide Applications Laboratory was developed. Detailed laboratory procedures were written in this study comprising preparation, handling and measurements of tree-ring samples in the Radionuclide Applications Laboratory.

NaA zeolite derived from blast furnace slag: its application for ammonium removal.

PubMed

Guo, Hongwei; Tang, Lizhen; Yan, Bingji; Wan, Kang; Li, Peng

2017-09-01

In this paper, high value added NaA zeolite material was prepared from blast furnace (BF) slag by hydrothermal method and its adsorption behavior on the removal of ammonium ion was investigated. It was found out that the synthetic NaA cubic zeolite with smaller crystal size obtained at nSiO 2 /nAl 2 O 3 = 2 and nH 2 O/nNaOH = 20 showed better adsorption performance. The kinetics of the adsorption of ammonium ion by synthesized NaA zeolite was fitted by the pseudo-second-order kinetic model. The intra-particle diffusion modeling reveals that two mixed rate-controlling mechanisms were involved in the adsorption process. The relatively high value of activation energy of 92.3 kJ·mol -1 indicates a high impact of temperature on the adsorption rate, and the nature of ammonium adsorption is chemical reaction rather than physisorption. Based on the thermodynamics calculations, the adsorption of ammonium was found to be an endothermic, spontaneous process. The adsorption isothermal analysis showed that the Langmuir model could be well fitted and a maximum adsorption capacity of 83.3 mg·g -1 of NH 4 + was obtained. Thus, it was demonstrated that by forming low cost NaA zeolite and using it for environmental remediation, the synchronous minimization of BF slag and ammonia nitrogen contamination could be achieved.

Preparation of highly ordered cubic NaA zeolite from halloysite mineral for adsorption of ammonium ions.

PubMed

Zhao, Yafei; Zhang, Bing; Zhang, Xiang; Wang, Jinhua; Liu, Jindun; Chen, Rongfeng

2010-06-15

Well-ordered cubic NaA zeolite was first synthesized using natural halloysite mineral with nanotubular structure as source material by hydro-thermal method. SEM and HRTEM images indicate that the synthesized NaA zeolite is cubic-shaped crystal with planar surface, well-defined edges and symmetrical and uniform pore channels. The adsorption behavior of ammonium ions (NH(4)(+)) from aqueous solution onto NaA zeolite was investigated as a function of parameters such as equilibrium time, pH, initial NH(4)(+) concentration, temperature and competitive cations. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms. A maximum adsorption capacity of 44.3 mg g(-1) of NH(4)(+) was achieved. The regeneration and reusable ability of this adsorbent was evaluated, and the results indicated that the recovered adsorbent could be used again for NH(4)(+) removal with nearly constant adsorption capacity. Thermodynamic parameters such as change in free energy (DeltaG(0)), enthalpy (DeltaH(0)) and entropy (DeltaS(0)) were also determined, which indicated that the adsorption was a spontaneous and exothermic process at ambient conditions. Compared with other adsorbents, the as-synthesized NaA zeolite displays a faster adsorption rate and higher adsorption capacity, which implies potential application for removing NH(4)(+) pollutants from wastewaters. Copyright 2010 Elsevier B.V. All rights reserved.

Occipital cortical proton MRS at 4 Tesla in human moderate MDMA polydrug users

PubMed Central

Cowan, Ronald L.; Bolo, Nicolas R.; Dietrich, Mary; Haga, Erica; Lukas, Scott E.; Renshaw, Perry F.

2007-01-01

The recreational drug MDMA (3,4, methylenedioxymethamphetamine; sold under the street name of Ecstasy) is toxic to serotonergic axons in some animal models of MDMA administration. In humans, MDMA use is associated with alterations in markers of brain function that are pronounced in occipital cortex. Among neuroimaging methods, magnetic resonance spectroscopy (MRS) studies of brain metabolites N-acetylaspartate (NAA) and myoinositol (MI) at a field strength of 1.5 Tesla (T) reveal inconsistent results in MDMA users. Because higher field strength proton MRS has theoretical advantages over lower field strengths, we used proton MRS at 4.0 T to study absolute concentrations of occipital cortical NAA and MI in a cohort of moderate MDMA users (n = 9) versus non-MDMA using (n = 7) controls. Mean NAA in non-MDMA users was 10.47 mM (± 2.51), versus 9.83 mM (± 1.94) in MDMA users. Mean MI in non-MDMA users was 7.43 mM (± 1.68), versus 6.57 mM (± 1.59) in MDMA users. There were no statistical differences in absolute metabolite levels for NAA and MI in occipital cortex of MDMA users and controls. These findings are not supportive of MDMA-induced alterations in NAA or MI levels in this small sample of moderate MDMA users. Limitations to this study suggest caution in the interpretation of these results. PMID:17574394

Occipital cortical proton MRS at 4 Tesla in human moderate MDMA polydrug users.

PubMed

Cowan, Ronald L; Bolo, Nicolas R; Dietrich, Mary; Haga, Erica; Lukas, Scott E; Renshaw, Perry F

2007-08-15

The recreational drug MDMA (3,4, methylenedioxymethamphetamine; sold under the street name of Ecstasy) is toxic to serotonergic axons in some animal models of MDMA administration. In humans, MDMA use is associated with alterations in markers of brain function that are pronounced in occipital cortex. Among neuroimaging methods, magnetic resonance spectroscopy (MRS) studies of brain metabolites N-acetylaspartate (NAA) and myoinositol (MI) at a field strength of 1.5 Tesla (T) reveal inconsistent results in MDMA users. Because higher field strength proton MRS has theoretical advantages over lower field strengths, we used proton MRS at 4.0 T to study absolute concentrations of occipital cortical NAA and MI in a cohort of moderate MDMA users (n=9) versus non-MDMA using (n=7) controls. Mean NAA in non-MDMA users was 10.47 mM (+/-2.51), versus 9.83 mM (+/-1.94) in MDMA users. Mean MI in non-MDMA users was 7.43 mM (+/-.68), versus 6.57 mM (+/-1.59) in MDMA users. There were no statistical differences in absolute metabolite levels for NAA and MI in occipital cortex of MDMA users and controls. These findings are not supportive of MDMA-induced alterations in NAA or MI levels in this small sample of moderate MDMA users. Limitations to this study suggest caution in the interpretation of these results.

The ratio of N-acetyl aspartate to glutamate correlates with disease duration of amyotrophic lateral sclerosis.

PubMed

Sako, Wataru; Abe, Takashi; Izumi, Yuishin; Harada, Masafumi; Kaji, Ryuji

2016-05-01

Glutamate (Glu)-induced excitotoxicity has been implicated in the neuronal loss of amyotrophic lateral sclerosis. To test the hypothesis that Glu in the primary motor cortex contributes to disease severity and/or duration, the Glu level was investigated using MR spectroscopy. Seventeen patients with amyotrophic lateral sclerosis were diagnosed according to the El Escorial criteria for suspected, possible, probable or definite amyotrophic lateral sclerosis, and enrolled in this cross-sectional study. We measured metabolite concentrations, including N-acetyl aspartate (NAA), creatine, choline, inositol, Glu and glutamine, and performed partial correlation between each metabolite concentration or NAA/Glu ratio and disease severity or duration using age as a covariate. Considering our hypothesis that Glu is associated with neuronal cell death in amyotrophic lateral sclerosis, we investigated the ratio of NAA to Glu, and found a significant correlation between NAA/Glu and disease duration (r=-0.574, p=0.02). The "suspected" amyotrophic lateral sclerosis patients showed the same tendency as possible, probable and definite amyotrophic lateral sclerosis patients in regard to correlation of NAA/Glu ratio with disease duration. The other metabolites showed no significant correlation. Our findings suggested that glutamatergic neurons are less vulnerable compared to other neurons and this may be because inhibitory receptors are mainly located presynaptically, which supports the notion of Glu-induced excitotoxicity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Proton MRS of the peritumoral brain.

PubMed

Chernov, Mikhail F; Kubo, Osami; Hayashi, Motohiro; Izawa, Masahiro; Maruyama, Takashi; Usukura, Masao; Ono, Yuko; Hori, Tomokatsu; Takakura, Kintomo

2005-02-15

Long-echo (TR: 2000 ms, TE: 136 ms) proton MRS of the cerebral tissue in the vicinity to intracranial lesion was done in 15 patients, mainly with parenchymal brain tumors. Significant decrease of N-acetylaspartate (NAA) (P<0.001) and more frequent presence of lactate (P<0.01) comparing with distant normal white matter were found in the perilesional brain tissue. The level of NAA in the perilesional brain tissue had negative associations with presence of lactate in the lesion (P<0.05), excess of lactate in the lesion compared to perilesional brain (P<0.01), grade of the perilesional edema (P<0.01) and patient's age (P<0.05). Multivariate analysis disclosed that identification of lactate in the lesion is associated with lower relative NAA content in the perilesional brain tissue, independently on the presence or absence of any other factor, including brain edema (P<0.001). In patients with lobar lesions who had at least one epileptic seizure during course of their disease the relative NAA content in the perilesional brain was significantly lower, comparing with those who were seizure-free (P<0.05). Therefore, lactate diffused from the tumor, or other metabolites secreted by lactate-producing neoplasm, should be considered as important contributors to the neuronal dysfunction in the surrounding brain. Decrease of NAA in the vicinity to intracranial lesions may reflect neuronal alteration responsible for associated epilepsy.

Micropropagation and hairy root culture of Ophiorrhiza alata Craib for camptothecin production.

PubMed

Ya-ut, Pornwilai; Chareonsap, Piyarat; Sukrong, Suchada

2011-12-01

An efficient system was developed for the in vitro micropropagation and hairy root culture of Ophiorrhiza alata Craib for camptothecin (CPT) production. Shoot multiplication on leaf and node explants from germinated seeds of O. alata was successful on half-strength Murashige and Skoog medium supplemented with varying amounts of kinetin and α-naphthaleneacetic acid. Node explants grown in vitro were successfully infected by Agrobacterium rhizogenes TISTR 1450 for the establishment of hairy root culture. The amount of CPT in various parts of O. alata was analyzed by HPLC. The accumulation of CPT in transformed hairy roots was twice that in soil-grown plants (785 ± 52 and 388 ± 32 μg/g dry wt, respectively). In the presence of a polystyrene resin (Diaion HP-20) that absorbed CPT, the CPT content in the culture media increased sevenfold compared with controls (1,036 and 151 μg per 250 ml medium, respectively). These results enable the feasible production of CPT of O. alata by means of a cell culture strategy. These measures can help safeguard the plant from extinction. © Springer Science+Business Media B.V. 2011

Encapsulation of nodal cuttings and shoot tips for storage and exchange of cassava germplasm.

PubMed

Danso, K E; Ford-Lloyd, B V

2003-04-01

We report the encapsulation of in vitro-derived nodal cuttings or shoot tips of cassava in 3% calcium alginate for storage and germplasm exchange purposes. Shoot regrowth was not significantly affected by the concentration of sucrose in the alginate matrix while root formation was. In contrast, increasing the sucrose concentration in the calcium chloride polymerisation medium significantly reduced regrowth from encapsulated nodal cuttings of accession TME 60444. Supplementing the alginate matrix with increased concentrations of 6-benzylaminopurine and alpha-naphthaleneacetic acid enhanced complete plant regrowth within 2 weeks. Furthermore, plant regrowth by encapsulated nodal cuttings and shoot tips was significantly affected by the duration of the storage period as shoot recovery decreased from almost 100% to 73.3% for encapsulated nodal cuttings and 94.4% to 60% for shoot tips after 28 days of storage. The high frequency of plant regrowth from alginate-coated micropropagules coupled with high viability percentage after 28 days of storage is highly encouraging for the exchange of cassava genetic resources. Such encapsulated micropropagules could be used as an alternative to synthetic seeds derived from somatic embryos.

AUX1 regulates root gravitropism in Arabidopsis by facilitating auxin uptake within root apical tissues.

PubMed Central

Marchant, A; Kargul, J; May, S T; Muller, P; Delbarre, A; Perrot-Rechenmann, C; Bennett, M J

1999-01-01

Plants employ a specialized transport system composed of separate influx and efflux carriers to mobilize the plant hormone auxin between its site(s) of synthesis and action. Mutations within the permease-like AUX1 protein significantly reduce the rate of carrier-mediated auxin uptake within Arabidopsis roots, conferring an agravitropic phenotype. We are able to bypass the defect within auxin uptake and restore the gravitropic root phenotype of aux1 by growing mutant seedlings in the presence of the membrane-permeable synthetic auxin, 1-naphthaleneacetic acid. We illustrate that AUX1 expression overlaps that previously described for the auxin efflux carrier, AtPIN2, using transgenic lines expressing an AUX1 promoter::uidA (GUS) gene. Finally, we demonstrate that AUX1 regulates gravitropic curvature by acting in unison with the auxin efflux carrier to co-ordinate the localized redistribution of auxin within the Arabidopsis root apex. Our results provide the first example of a developmental role for the auxin influx carrier within higher plants and supply new insight into the molecular basis of gravitropic signalling. PMID:10205161

Dimensions of Acculturation in Native American College Students

ERIC Educational Resources Information Center

Reynolds, Amy L.; Sodano, Sandro M.; Ecklund, Timothy R.; Guyker, Wendy

2012-01-01

Exploratory and confirmatory factor analyses were applied to the responses of two respective independent samples of Native American college students on the Native American Acculturation Scale (NAAS). Three correlated dimensions were found to underlie NAAS items and these dimensions may also comprise a broader higher order dimension of Native…

Properties of Zeolite A Obtained from Powdered Laundry Detergent: An Undergraduate Experiment.

ERIC Educational Resources Information Center

Smoot, Alison L.; Lindquist, David A.

1997-01-01

Presents experiments that introduce students to the myriad properties of zeolites using the sodium form of zeolite A (Na-A) from laundry detergent. Experiments include extracting Na-A from detergent, water softening properties, desiccant properties, ion-exchange properties, and Zeolite HA as a dehydration catalyst. (JRH)

Analysis of medieval limestone sculpture from southwestern France and the Paris Basin by NAA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holmes, L.; Harbottle, G.

1994-12-31

Compositional characterization of limestone from sources known to medieval craftsmen and from the monuments they built can be used in conjunction with stylistic and iconographic criteria to infer geographic origin of sculptures that have lost their histories. Limestone from 47 quarrying locations in France and from numerous medieval monuments have been subjected to neutron activation analysis (NAA) to form the nucleus of the Brookhaven Limestone Database. Even though the method and techniques of NAA are well established, this paper briefly summarizes the parameters and experimental conditions useful for determining those concentration variables for which limestone from different sources exhibits significantmore » and reproducible differences.« less

Newspaper Association of America Foundation: Report for 1991-92.

ERIC Educational Resources Information Center

American Newspaper Publishers Association Foundation, Washington, DC.

This document contains the 1991-92 annual report of the Newspaper Association of America (NAA) Foundation. The group previously was known as the American Newspaper Publishers Association (ANPA) Foundation. Throughout the report, the foundation is referred to as ANPA when referring to past activities, and NAA when referring to the present and…

Art Competition Encourages Student Dreams

ERIC Educational Resources Information Center

Gartel, Laurence

2010-01-01

In 1971, members of the Naples Art Association (NAA) in Naples, Florida, initiated a scholarship program designed to encourage local young artists to realize their dreams of becoming professionals in the visual arts. Since then, awards have been given annually by the NAA to Collier County high-school students in conjunction with an exhibition of…

Imaging Intelligence with Proton Magnetic Resonance Spectroscopy

ERIC Educational Resources Information Center

Jung, Rex E.; Gasparovic, Charles; Chavez, Robert S.; Caprihan, Arvind; Barrow, Ranee; Yeo, Ronald A.

2009-01-01

Proton magnetic resonance spectroscopy ([to the first power]H-MRS) is a technique for the assay of brain neurochemistry "in vivo." N-acetylaspartate (NAA), the most prominent metabolite visible within the [to the first power]H-MRS spectrum, is found primarily within neurons. The current study was designed to further elucidate NAA-cognition…

Neurochemical alterations associated with borderline personality disorder.

PubMed

Atmaca, Murad; Karakoc, Tevfik; Mermi, Osman; Gurkan Gurok, M; Yildirim, Hanefi

2015-01-01

In neuroimaging on borderline personality disorder, prior studies focused on the hippocampus and amygdala, as mentioned above. However, no study investigated whether there were neurochemical changes in the patients with borderline personality disorder. Therefore, in the present study, we aimed to investigate neurochemical change of patients diagnosed with borderline disorder and hypothesized that neurochemicals would change in the hippocampus region of these patients. Seventeen patients and the same number of healthy control subjects were analyzed by using a 1.5 Tesla GE Signa Imaging System. N-acetylaspartate (NAA), choline compounds (CHO), and creatine (CRE) values of hippocampal region were measured. The mean NAA/CRE ratio in the hippocampus region was significantly reduced in the patients with borderline personality disorder compared to that of healthy control subjects, In addition, NAA/CHO ratio of the patients with borderline personality disorder was also significantly reduced when compared to that of healthy subjects. There was no difference in the ratio of CHO/CRE. In summary, we present evidence for reduced NAA in the patients with borderline personality disorder. © 2015, The Author(s).

Sample registration software for process automation in the Neutron Activation Analysis (NAA) Facility in Malaysia nuclear agency

NASA Astrophysics Data System (ADS)

Rahman, Nur Aira Abd; Yussup, Nolida; Salim, Nazaratul Ashifa Bt. Abdullah; Ibrahim, Maslina Bt. Mohd; Mokhtar, Mukhlis B.; Soh@Shaari, Syirrazie Bin Che; Azman, Azraf B.; Ismail, Nadiah Binti

2015-04-01

Neutron Activation Analysis (NAA) had been established in Nuclear Malaysia since 1980s. Most of the procedures established were done manually including sample registration. The samples were recorded manually in a logbook and given ID number. Then all samples, standards, SRM and blank were recorded on the irradiation vial and several forms prior to irradiation. These manual procedures carried out by the NAA laboratory personnel were time consuming and not efficient. Sample registration software is developed as part of IAEA/CRP project on `Development of Process Automation in the Neutron Activation Analysis (NAA) Facility in Malaysia Nuclear Agency (RC17399)'. The objective of the project is to create a pc-based data entry software during sample preparation stage. This is an effective method to replace redundant manual data entries that needs to be completed by laboratory personnel. The software developed will automatically generate sample code for each sample in one batch, create printable registration forms for administration purpose, and store selected parameters that will be passed to sample analysis program. The software is developed by using National Instruments Labview 8.6.

Methylcellulose-Directed Synthesis of Nanocrystalline Zeolite NaA with High CO₂ Uptake.

PubMed

Shakarova, Dilshod; Ojuva, Arto; Bergström, Lennart; Akhtar, Farid

2014-07-28

Zeolite NaA nanocrystals with a narrow particle size distribution were prepared by template-free hydrothermal synthesis in thermo-reversible methylcellulose gels. The effects of the amount of methylcellulose, crystallization time and hydrothermal treatment temperature on the crystallinity and particle size distribution of the zeolite NaA nanocrystals were investigated. We found that the thermogelation of methylcellulose in the alkaline Na₂O-SiO₂-Al₂O₃-H₂O system played an important role in controlling the particle size. The synthesized zeolite nanocrystals are highly crystalline, as demonstrated by X-ray diffraction (XRD), and scanning electron microscopy (SEM) shows that the nanocrystals can also display a well-defined facetted morphology. Gas adsorption studies on the synthesized nanocrystalline zeolite NaA showed that nanocrystals with a size of 100 nm displayed a high CO₂ uptake capacity (4.9 mmol/g at 293 K at 100 kPa) and a relatively rapid uptake rate compared to commercially available, micron-sized particles. Low-cost nanosized zeolite adsorbents with a high and rapid uptake are important for large scale gas separation processes, e.g., carbon capture from flue gas.

Micropropagation of Hedychium coronarium J. Koenig through rhizome bud.

PubMed

Mohanty, Pritam; Behera, Shashikanta; Swain, Swasti S; Barik, Durga P; Naik, Soumendra K

2013-10-01

An optimized protocol was developed for in vitro plant regeneration of a medicinally important herb Hedychium coronarium J. Koenig using sprouted buds of rhizomes. The rhizomes with sprouted bud were inoculated on Murashige and Skoog (Physiol Plant 15:473-497, 1962) medium (MS) supplemented with either N(6)-benzyladenine (BA) alone (1.0-4.0 mg L(-1)) or in combination with 0.5 mg L(-1) naphthalene acetic acid (NAA). Of these combinations, MS supplemented with a combination of 2.0 mg L(-1) BA and 0.5 mg L(-1) NAA was most effective. In this medium, best shoots (3.6) and roots (4.0) regeneration was observed simultaneously with an average shoot and root length of 4.7 cm and 4.2 cm respectively. Regeneration of shoots and roots in the same medium at the same time (One step shoot and root regeneration) reduced the time for production of in vitro plantlets and eliminates the media cost of rooting. Cent-percent (100 %) success in plant establishment was observed in both gradual acclimatization process as well as when plants were directly transferred to outdoor in clay pots containing a mixture of garden soil and sand (2:1) without any sequential acclimatization stage.

[In vitro flowering of cultures from a hybrid of Cymbidium goeringii and C. hybridium].

PubMed

Zheng, Li-Ming; Pang, Ji-Liang

2006-06-01

Wild-type female spring orchid (Cymbidium goeringii) was crossed with male Cymbidium hybridium. Over eight hundred protocorm clones were obtained from hybrid offsprings. Among them, one protocorm clone was identified to differentiate visible floral buds two months after subculture in vitro (Plate I). The protocorms and shoots derived from this clone were further used in studying the effects of abscisic acid (ABA) and paclobutrazol (PP333) pretreatment as well as different concentrations of 6-benzyladenine (6-BA) on floral bud differentiation. The optimum combination of hormones in floral bud induction was 6-BA 1.0 mg/L and NAA 0.1 mg/L, and total frequency of floral bud formation was up to 31% (Table 1). The optimum length of shoots used in floral bud induction was 1-2 cm, and the frequency of floral bud formation was 19% (Table 1). The increase in total frequency was not significant in floral bud induction from protocorms and shoots with length of 1-2 cm or 2-4 cm cultured on MS medium containing 6-BA 1.0 mg/L and NAA 0.1 mg/L after pretreatment on MS medium supplemented with ABA 0.5 mg/L and PP333 0.5 mg/L for 35 d (Table 2).

[Magnetic resonance spectroscopy of metabolic changes in mice brain after 2-deoxy-D-glucose injection].

PubMed

Moshkin, M P; Akulov, A E; Petrovskiĭ, D V; Saĭk, O V; Petrovskiĭ, E D; Savelov, A A; Koptug, I V

2012-10-01

In vivo proton magnetic resonance spectroscopy (1H MRS) of ICR male mice was used to study the brain (hippocampus) metabolic response to the acute deficiency of the available energy or to the pro-inflammatory stimulus. Inhibition of glycolysis by means of an intraperitoneal injection with 2-deoxy-D-glucose (2DG) reduced the levels of gamma-aminobutiric acid (GABA), N-acetylaspartate (NAA) and choline compounds, and at the same time increased the levels of glutamate and glutamine. An opposite effect was found after injection with bacterial lipopolysaccharide (LPS)--a very common pro-inflammatory inducer. An increase in the amounts of GABA, NAA and choline compounds in the brain occurred three hours after the injection of LPS. Different metabolic responses to the energy deficiency and the pro-inflammatory stimuli can explain the contradictory results of the brain MRS studies under neurodegenerative pathology, which is accompanied by both mitochondrial dysfunction and inflammation. Prevalence of the excitatory metabolites such as glutamate and glutamine in 2DG treated mice is in good agreement with excitation observed during temporary reduction of the available energy under acute hypoxia or starvation. In turn, LPS, as an inducer of the sickness behavior, shifts brain metabolic pattern to prevalence of the inhibitory neurotransmitter GABA.

Chronic intermittent but not constant hypoxia decreases NAA/Cr ratios in neonatal mouse hippocampus and thalamus.

PubMed

Douglas, Robert M; Miyasaka, Naoyuki; Takahashi, Kan; Latuszek-Barrantes, Adrianna; Haddad, Gabriel G; Hetherington, Hoby P

2007-03-01

Chronic constant hypoxia (CCH) and chronic intermittent hypoxia (CIH) are known to have deleterious effects on the central nervous system. Because of the difference in the pattern of hypoxic exposure, it is possible that the pathological outcome would vary. The N-acetyl aspartate/creatine (NAA/Cr) ratio is a reliable marker of neuronal integrity, and this can be noninvasively measured by proton nuclear magnetic resonance spectroscopy. P2 CD1 mouse pups with their dams were exposed to either CCH, where the Fi(O(2)) was maintained at 11% continuously or to CIH, where the Fi(O(2)) was varied between 21 and 11% every 4 min. P30 mice exposed to intermittent hypoxia for 4 wk demonstrated a significant decrease in the NAA/Cr ratio in the hippocampus and thalamus, which was reversed by a subsequent exposure to 4 wk of normoxia. Meanwhile, mice exposed to 4 wk of constant hypoxia did not demonstrate any differences in their NAA/Cr ratios from controls in these brain regions. These results indicate that an intermittent pattern of hypoxic exposure may have a more adverse effect on neuronal function and integrity than a continuous one. The reversal of NAA/Cr levels to baseline during the return to normoxia indicates that therapeutic strategies targeted at alleviating the intermittent hypoxic stress in diseases, such as obstructive sleep apnea, have the potential for inducing significant neurocognitive recovery in these patients.

Association between memory impairment and brain metabolite concentrations in North Korean refugees with posttraumatic stress disorder.

PubMed

Shin, Jung Eun; Choi, Chi-Hoon; Lee, Jong Min; Kwon, Jun Soo; Lee, So Hee; Kim, Hyun-Chung; Han, Na Young; Choi, Soo-Hee; Yoo, So Young

2017-01-01

Individuals with posttraumatic stress disorder (PTSD) had experiences of enormous psychological stress that can result in neurocognitive and neurochemical changes. To date, the causal relationship between them remains unclear. The present study is to investigate the association between neurocognitive characteristics and neural metabolite concentrations in North Korean refugees with PTSD. A total of 53 North Korean refugees with or without PTSD underwent neurocognitive function tests. For neural metabolite scanning, magnetic resonance spectroscopy of the hippocampus and anterior cingulate cortex (ACC) has been conducted. We assessed between-group differences in neurocognitive test scores and metabolite levels. Additionally, a multiple regression analysis was carried out to evaluate the association between neurocognitive function and metabolite levels in patients with PTSD. Memory function, but not other neurocognitive functions, was significantly lower in the PTSD group compared with the non-PTSD group. Hippocampal N-acetylaspartate (NAA) levels were not different between groups; however, NAA levels were significantly lower in the ACC of the PTSD group than the non-PTSD group (t = 2.424, p = 0.019). The multiple regression analysis showed a negative association between hippocampal NAA levels and delayed recall score on the auditory verbal learning test (β = -1.744, p = 0.011) in the non-PTSD group, but not in the PTSD group. We identified specific memory impairment and the role of NAA levels in PTSD. Our findings suggest that hippocampal NAA has a protective role in memory impairment and development of PTSD after exposure to traumatic events.

Brain metabolite changes in patients with type 2 diabetes and cerebral infarction using proton magnetic resonance spectroscopy.

PubMed

Zhang, Min; Sun, Xinhai; Zhang, Zhengjun; Meng, Qiang; Wang, Yuzhong; Chen, Jing; Ma, Xueqin; Geng, Houfa; Sun, Lin

2014-01-01

The aim of this study was to investigate the possible brain metabolic alterations in patients with type 2 diabetes mellitus (T2DM) and cerebral infarction (DMCI) using proton magnetic resonance spectroscopy (MRS). Thirty-four patients with T2DM and DMCI were scanned together with 33 patients with nondiabetic cerebral infarction (NDCI) on a 1.5-T MRI/MRS imager. Voxels were placed in the infarcted area and the contralateral normal area in the basal ganglia. N-acetylaspartate (NAA)/creatine (Cr), choline (Cho)/Cr, and lactate (Lac)/Cr ratios were calculated. Cerebral NAA/Cr ratios in the infarcted area were lower than those in the contralateral normal area of the NDCI group. There was a significant decrease in NAA/Cr in the infarcted area of the DMCI group as compared with the infarcted area of the NDCI group. NAA/Cr ratios in the contralateral normal area of DMCI group were lower than those of the NDCI group. Lac/Cr ratios were increased in the infarcted area of both the DMCI group and NDCI group, and Lac/Cr ratios tended to be higher in the infarcted area of the DMCI group than those of the NDCI group. Glycosylated hemoglobin (HbA1c) levels were negatively correlated with NAA/Cr ratios. The study suggested that the metabolite changes were different between DMCI patients and NDCI patients, which may provide important information in the treatment of DMCI.

Reduced NAA levels in the dorsolateral prefrontal cortex of young bipolar patients.

PubMed

Sassi, Roberto B; Stanley, Jeffrey A; Axelson, David; Brambilla, Paolo; Nicoletti, Mark A; Keshavan, Matcheri S; Ramos, Renato T; Ryan, Neal; Birmaher, Boris; Soares, Jair C

2005-11-01

Converging evidence implicates prefrontal circuits in the pathophysiology of bipolar disorder. Proton spectroscopy studies performed in adult bipolar patients assessing prefrontal regions have suggested decreased levels of N-acetylaspartate (NAA), a putative marker of neuronal integrity. In order to examine whether such abnormalities would also be found in younger patients, a 1H spectroscopy study was conducted that focused on the dorsolateral prefrontal cortex of children and adolescents with bipolar disorder. The authors examined the levels of NAA, creatine plus phosphocreatine, and choline-containing molecules in the left dorsolateral prefrontal cortex of 14 bipolar disorder patients (mean age=15.5 years, SD=3, eight female) and 18 healthy comparison subjects (mean age=17.3, SD=3.7, seven female) using short echo time, single-voxel in vivo 1H spectroscopy. Absolute metabolite levels were determined using the water signal as an internal reference. Bipolar patients presented significantly lower NAA levels and a significant inverse correlation between choline-containing molecules and number of previous affective episodes. No differences were found for other metabolites. These findings suggest that young bipolar patients have decreased NAA levels in the dorsolateral prefrontal cortex, similar to what was previously reported in adult patients. Such changes may reflect an underdevelopment of dendritic arborizations and synaptic connections. These neuronal abnormalities in the dorsolateral prefrontal cortex of bipolar disorder youth are unlikely to represent long-term degenerative processes, at least in the subgroup of patients where the illness had relatively early onset.

Comparison of T1 and T2 metabolite relaxation times in glioma and normal brain at 3 T

PubMed Central

Li, Yan; Srinivasan, Radhika; Ratiney, Helene; Lu, Ying; Chang, Susan M.; Nelson, Sarah J.

2011-01-01

Purpose To measure T1 and T2 relaxation times of metabolites in glioma patients at 3T and to investigate how these values influence the observed metabolite levels. Materials and Methods Twenty-three patients with gliomas and ten volunteers were studied with single voxel 2D J-resolved PRESS using a 3T MR scanner. Voxels were chosen in normal appearing white matter and in regions of tumor. The T1 and T2 of choline containing compounds (Cho), creatine (Cr) and N-acetyl aspartate (NAA) were estimated. Results Metabolite T1 relaxation values in gliomas were not significantly different from values in normal white matter. The T2 of Cho and Cr were statistically significantly longer for Grade 4 gliomas than for normal white matter but the T2 of NAA was similar. These differences were large enough to impact the corrections of metabolite levels for relaxation times with tumor grade in terms of metabolite ratios (P<0.001). Conclusion The differential increase in T2 for Cho and Cr relative to NAA means that the ratios of Cho/NAA and Cr/NAA are higher in tumor at longer echo times relative to values in normal appearing brain. Having this information may be useful in defining the acquisition parameters for optimizing contrast between tumor and normal tissue in MRSI data, where limited time is available and only one echo time can be used. PMID:18666155

Magnetic resonance spectroscopy reveals oral Lactobacillus promotion of increases in brain GABA, N-acetyl aspartate and glutamate.

PubMed

Janik, Rafal; Thomason, Lynsie A M; Stanisz, Andrew M; Forsythe, Paul; Bienenstock, John; Stanisz, Greg J

2016-01-15

The gut microbiome has been shown to regulate the development and functions of the enteric and central nervous systems. Its involvement in the regulation of behavior has attracted particular attention because of its potential translational importance in clinical disorders, however little is known about the pathways involved. We previously have demonstrated that administration of Lactobacillus rhamnosus (JB-1) to healthy male BALB/c mice, promotes consistent changes in GABA-A and -B receptor sub-types in specific brain regions, accompanied by reductions in anxiety and depression-related behaviors. In the present study, using magnetic resonance spectroscopy (MRS), we quantitatively assessed two clinically validated biomarkers of brain activity and function, glutamate+glutamine (Glx) and total N-acetyl aspartate+N-acetyl aspartyl glutamic acid (tNAA), as well as GABA, the chief brain inhibitory neurotransmitter. Mice received 1×10(9) cfu of JB-1 per day for 4weeks and were subjected to MRS weekly and again 4weeks after cessation of treatment to ascertain temporal changes in these neurometabolites. Baseline concentrations for Glx, tNAA and GABA were equal to 10.4±0.3mM, 8.7±0.1mM, and 1.2±0.1mM, respectively. Delayed increases were first seen for Glx (~10%) and NAA (~37%) at 2weeks which persisted only to the end of treatment. However, Glx was still elevated 4weeks after treatment had ceased. Significantly elevated GABA (~25%) was only seen at 4weeks. These results suggest specific metabolic pathways in our pursuit of mechanisms of action of psychoactive bacteria. They also offer through application of standard clinical neurodiagnostic techniques, translational opportunities to assess biomarkers accompanying behavioral changes induced by alterations in the gut microbiome. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

Elevated Glutamate Levels in the Left Dorsolateral Prefrontal Cortex Are Associated with Higher Cravings for Alcohol.

PubMed

Frye, Mark A; Hinton, David J; Karpyak, Victor M; Biernacka, Joanna M; Gunderson, Lee J; Geske, Jennifer; Feeder, Scott E; Choi, Doo-Sup; Port, John D

2016-08-01

Quantifying craving longitudinally during the course of withdrawal, early abstinence, and relapse is essential for optimal management of alcohol use disorder (AUD). In an effort to identify biological correlates of craving, we used proton magnetic resonance spectroscopy (1H-MRS) to investigate the correlation between craving and glutamate levels in the left dorsolateral prefrontal cortex (LDLPFC) of patients with AUD. Participants underwent 1H-MRS of the LDLPFC with 2-dimensional J-resolved (2DJ) averaged PRESS. MRS data were processed with LCModel and cerebrospinal fluid (CSF)-corrected to generate metabolite concentrations. The Penn Alcohol Craving Scale (PACS) and the 30-day time line follow-back (TLFB 30) were used to quantify craving for alcohol and drinking patterns, respectively. There was a statistically significant positive correlation between CSF-corrected glutamate ([Glu]) levels and PACS scores (n = 14; p = 0.005). When PACS scores were dichotomized (< or ≥median = 16), [Glu] levels were significantly higher in the high- versus low-craving group (p = 0.007). In addition, there was a significant negative correlation between CSF-corrected N-acetyl aspartic acid ([NAA]) levels and mean number of drinks per drinking day in the past month (n = 13; TLFB 30; p = 0.012). When mean TLFB 30 was dichotomized (< or ≥median = 7.86), [NAA] levels were significantly lower in subjects that consumed more alcoholic beverages. There was no significant correlation between [Glu] and [NAA] levels with other measures of drinking behavior and or depression symptom severity. While limited by small sample size, these data suggest that glutamate levels in LDLPFC are associated with alcohol craving intensity in patients with AUD. Further study with larger sample size is needed to replicate this finding and evaluate the merits of glutamate spectroscopy as a biological correlate of alcohol craving intensity and a guide to treatment interventions. Copyright © 2016 by the Research Society on Alcoholism.

N-acetyl-aspartate levels correlate with intra-axonal compartment parameters from diffusion MRI.

PubMed

Grossman, Elan J; Kirov, Ivan I; Gonen, Oded; Novikov, Dmitry S; Davitz, Matthew S; Lui, Yvonne W; Grossman, Robert I; Inglese, Matilde; Fieremans, Els

2015-09-01

Diffusion MRI combined with biophysical modeling allows for the description of a white matter (WM) fiber bundle in terms of compartment specific white matter tract integrity (WMTI) metrics, which include intra-axonal diffusivity (Daxon), extra-axonal axial diffusivity (De||), extra-axonal radial diffusivity (De┴), axonal water fraction (AWF), and tortuosity (α) of extra-axonal space. Here we derive these parameters from diffusion kurtosis imaging to examine their relationship to concentrations of global WM N-acetyl-aspartate (NAA), creatine (Cr), choline (Cho) and myo-Inositol (mI), as measured with proton MR spectroscopy ((1)H-MRS), in a cohort of 25 patients with mild traumatic brain injury (MTBI). We found statistically significant (p<0.05) positive correlations between NAA and Daxon, AWF, α, and fractional anisotropy; negative correlations between NAA and De,┴ and the overall radial diffusivity (D┴). These correlations were supported by similar findings in regional analysis of the genu and splenium of the corpus callosum. Furthermore, a positive correlation in global WM was noted between Daxon and Cr, as well as a positive correlation between De|| and Cho, and a positive trend between De|| and mI. The specific correlations between NAA, an endogenous probe of the neuronal intracellular space, and WMTI metrics related to the intra-axonal space, combined with the specific correlations of De|| with mI and Cho, both predominantly present extra-axonally, corroborate the overarching assumption of many advanced modeling approaches that diffusion imaging can disentangle between the intra- and extra-axonal compartments in WM fiber bundles. Our findings are also generally consistent with what is known about the pathophysiology of MTBI, which appears to involve both intra-axonal injury (as reflected by a positive trend between NAA and Daxon) as well as axonal shrinkage, demyelination, degeneration, and/or loss (as reflected by correlations between NAA and De┴, AWF, and α). Copyright © 2015 Elsevier Inc. All rights reserved.

Magnetic resonance spectroscopy of current hand amputees reveals evidence for neuronal-level changes in former sensorimotor cortex

PubMed Central

Choi, In-Young; Lee, Phil; Peng, Huiling; Kaufman, Christina L.; Frey, Scott H.

2017-01-01

Deafferentation is accompanied by large-scale functional reorganization of maps in the primary sensory and motor areas of the hemisphere contralateral to injury. Animal models of deafferentation suggest a variety of cellular-level changes including depression of neuronal metabolism and even neuronal death. Whether similar neuronal changes contribute to patterns of reorganization within the contralateral sensorimotor cortex of chronic human amputees is uncertain. We used functional MRI-guided proton magnetic resonance spectroscopy to test the hypothesis that unilateral deafferentation is associated with lower levels of N-acetylaspartate (NAA, a putative marker of neuronal integrity) in the sensorimotor hand territory located contralateral to the missing hand in chronic amputees (n = 19) compared with the analogous hand territory of age- and sex-matched healthy controls (n = 28). We also tested whether former amputees [i.e., recipients of replanted (n = 3) or transplanted (n = 2) hands] exhibit NAA levels that are indistinguishable from controls, possible evidence for reversal of the effects of deafferentation. As predicted, relative to controls, current amputees exhibited lower levels of NAA that were negatively and significantly correlated with the time after amputation. Contrary to our prediction, NAA levels in both replanted and transplanted patients fell within the range of the current amputees. We suggest that lower levels of NAA in current amputees reflects altered neuronal integrity consequent to chronic deafferentation. Thus local changes in NAA levels may provide a means of assessing neuroplastic changes in deafferented cortex. Results from former amputees suggest that these changes may not be readily reversible through reafferentation. NEW & NOTEWORTHY This study is the first to use functional magnetic resonance-guided magnetic resonance spectroscopy to examine neurochemical mechanisms underlying functional reorganization in the primary somatosensory and motor cortices consequent to upper extremity amputation and its potential reversal through hand replantation or transplantation. We provide evidence for selective alteration of cortical neuronal integrity associated with amputation-related deafferentation that may not be reversible. PMID:28179478

Experience of diffusion tensor imaging and 1H spectroscopy for outcome prediction in severe traumatic brain injury: Preliminary results.

PubMed

Tollard, Eléonore; Galanaud, Damien; Perlbarg, Vincent; Sanchez-Pena, Paola; Le Fur, Yann; Abdennour, Lamine; Cozzone, Patrick; Lehericy, Stéphane; Chiras, Jacques; Puybasset, Louis

2009-04-01

The objective of the study is to test whether multimodal magnetic resonance imaging can provide a reliable outcome prediction of the clinical status, focusing on consciousness at 1 year after severe traumatic brain injury (TBI). Single center prospective cohort with consecutive inclusions. Critical Care Neurosurgical Unit of a university hospital. Forty-three TBI patients not responding to simple orders after sedation cessation and 15 healthy controls. A multimodal magnetic resonance imaging combining morphologic sequences, diffusion tensor imaging (DTI), and H proton magnetic resonance spectroscopy (MRS) was performed 24 +/- 11 days after severe TBI. The ability of DTI and MRS to predict 1-year outcome was assessed by linear discriminant analysis (LDA). Robustness of the classification was tested using a bootstrap procedure. Fractional anisotropy (FA) was computed as the mean of values at discrete brain sites in the infratentorial and supratentorial regions. The N-acetyl aspartate/creatine (NAA/Cr) ratio was measured in the thalamus, lenticular nucleus, insular cortex, occipital periventricular white matter, and pons. After 1 year, 19 (44%) patients had unfavorable outcomes (death, persistent vegetative state, or minimally conscious state) and 24 (56%) favorable outcomes (normal consciousness with or without functional impairments). Analysis of variance was performed to compare FA and NAA/Cr in the two outcome groups and controls. FA and MRS findings showed highly significant differences between the outcome groups, with significant variables by LDA being supratentorial FA, NAA/Cr (pons), NAA/Cr (thalamus), NAA/Cr (insula), and infratentorial FA. LDA of combined FA and MRS data clearly separated the unfavorable outcome, favorable outcome, and control groups, with no overlap. Unfavorable outcome was predicted with up to 86% sensitivity and 97% specificity; these values were better than those obtained with DTI or MRS alone. FA and NAA/Cr hold potential as quantitative outcome-prediction tools at the subacute phase of TBI.

Synthesis and characterization of LTA nanozeolite using barley husk silica: Mercury removal from standard and real solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azizi, Seyed Naser, E-mail: azizi@umz.ac.ir; Dehnavi, Ahmad Roozbehani, E-mail: Roozbehanisulfur@yahoo.com; Joorabdoozha, Amir

2013-05-15

Highlights: ► Silica extraction from barley husk with high purity for the synthesis of A nanozeolite. ► Free template A nanozeolite synthesized via new source of silica at low temperature. ► Optimization of SiO{sub 2}/Al{sub 2}O{sub 3}, Na{sub 2}O/SiO{sub 2} ratios, temperature and time of the synthesis. ► Utilizing of synthesized A nanozeolite for mercury removal from aqueous solutions. ► Mercury removal at optimized pH, contact time and adsorbent dose from real solution. - Abstract: In this study, synthesized Lined Type A (LTA) nanozeolite from barley husk silica (BHS) was used for mercury removal from standard and real aqueous solutions.more » The BHS in amorphous phase with 80% purity was extracted from barley husk ash (BHA), and used effectively as a new source of silica for the synthesis of NaA nanozeolite. The NaA nanocrystal in pure phase has been synthesized at low temperature, without adding any organic additives. The effects of heating time, reaction temperature, SiO{sub 2}/Al{sub 2}O{sub 3}, and Na{sub 2}O/SiO{sub 2} mole ratios on the crystallization of NaA nanozeolite were studied. The adsorption capacity of mercury (II) was studied as a function of pH, contact time, and amount of adsorbent. The crystallization of NaA nanozeolite from BHS was characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), Brunauer–Emmett–Teller (BET), and FTIR techniques. Moreover, concentration of Hg{sup 2+} ions in the aqueous solutions was analyzed by hydride generation atomic absorption spectroscopy method (HG-AAS). The standard and real samples analysis showed that NaA nanozeolite is capable of Hg{sup 2+} ions removal from the aqueous solutions. Efficiency of mercury (II) adsorption from real solutions onto the nano-sized NaA zeolite was 98%.« less

High frequency organogenesis in hypocotyl, cotyledon, leaf and petiole explants of broccoli (Brassica oleracea L. var. italica), an important vegetable crop.

PubMed

Kumar, Pankaj; Srivastava, D K

2015-04-01

Broccoli (Brassica oleracea L. var. italica) is an important, nutritionally rich vegetable crop, but severely affected by environmental stresses, pests and diseases which cause massive yield and quality losses. Genetic manipulation is becoming an important method for broccoli improvement. In the present study, a reproducible and highly efficient protocol for obtaining organogenesis from hypocotyl, cotyledon, leaf and petiole explants of broccoli (Brassica oleracea L. var. italica cv. Solan green head) has been developed. Hypocotyl and cotyledon explants were used from 10 to 12 days old aseptically grown seedlings whereas leaf and petiole explants were excised from 18 to 20 days old green house grown seedlings and surface sterilized. These explants were cultured on shoot induction medium containing different concentration and combination of BAP and NAA. High efficiency shoot regeneration has been achieved in hypocotyl (83.33 %), cotyledon (90.11 %), leaf (62.96 %) and petiole (91.10 %) explants on MS medium supplemented with 3.5 mg/l BAP + 0.019 mg/l NAA 2.5 mg/l BAP + 0.5 mg/l NAA, 4.0 mg/l BAP + 0.5 mg/l NAA and 4.5 mg/l BAP + 0.019 mg/l NAA respectively. Petiole explants showed maximum shoot regeneration response as compared to other explants. MS medium supplemented with 0.10 mg/l NAA was found best for root regeneration (100 %) from in vitro developed shoots. The regenerated complete plantlets were transferred to the pots containing cocopeat and successfully acclimatized. This optimized regeneration protocol can be efficiently used for genetic transformation in broccoli. This is the first comparative report on multiple shoot induction using four different types of explants viz. hypocotyl, cotyledon, leaf and petiole.

Contributions of endothelial nitric oxide synthase, noradrenaline, and neuropeptide Y to local warming-induced cutaneous vasodilatation in men.

PubMed

Hodges, Gary J; Sparks, Paul A

2013-11-01

We performed a two-part study to determine the roles of endothelial nitric oxide synthase (eNOS) and the vasoconstrictor nerves neurotransmitters noradrenaline (NA) and neuropeptide Y (NPY) in the cutaneous vasodilator response to local skin warming. Forearm skin sites were instrumented with intradermal microdialysis fibres, local heaters, and laser-Doppler flow (LDF) probes. Sites were locally heated from 34 to 42°C. LDF was expressed as cutaneous vascular conductance (CVC; LDF/mean arterial pressure). In Part I, we tested whether sympathetic noradrenergic nerves acted via eNOS. In 8 male participants, treatments were as follows: 1) untreated; 2) bretylium tosylate (BT), preventing sympathetic neurotransmitter release; 3) l-NAA to inhibit eNOS; and 4) combined BT+l-NAA. At treated sites, the initial peak response was markedly reduced, and the plateau phase response to 35min of local warming was also reduced (P<0.05), which was not different among those sites (P>0.05). In Part II, we tested whether NA and NPY were involved in the vasodilator response to local warming. In Part IIa, treatments were: 1) untreated; 2) propranolol and yohimbine to antagonize α- and β-receptors; 3) l-NAA; and 4) combined propranolol, yohimbine, and l-NAA. In Part IIb, conditions were: 1) untreated; 2) BIBP to antagonize Y1-receptors; 3) l-NAA; and 4) combined BIBP and l-NAA. All treatments caused a reduction in the initial peak and plateau responses to local skin warming (P<0.05). The results of Part II indicate that both NA and NPY play roles in the cutaneous vasodilator response and their actions are achieved via eNOS. These data indicate that NA and NPY are involved in the initial, rapid rise in skin blood flow at the onset of local skin warming. However, their vasodilator actions in response to local skin warming appears to be manifested through eNOS. © 2013.

Brain metabolite abnormalities in ventromedial prefrontal cortex are related to duration of hypercortisolism and anxiety in patients with Cushing's syndrome.

PubMed

Crespo, Iris; Santos, Alicia; Gómez-Ansón, Beatriz; López-Mourelo, Olga; Pires, Patricia; Vives-Gilabert, Yolanda; Webb, Susan M; Resmini, Eugenia

2016-09-01

Chronic exposure to excessive glucocorticoid (GC) concentration in Cushing's syndrome (CS) can affect the brain structurally and functionally; ventromedial prefrontal cortex (vmPFC) is rich in GC receptors and therefore particularly vulnerable to excessive GC concentration. Proton magnetic resonance spectroscopy ((1)H-MRS) is a sensitive, non-invasive imaging technique that provides information on brain metabolites in vivo. Our aim was to investigate metabolite concentrations in vmPFC of CS patients and their relationship with clinical outcome. Twenty-two right-handed CS patients (7 active/15 in remission, 19 females, 41.6 ± 12.3 years) and 22 right-handed healthy controls (14 females, 41.7 ± 11 years) underwent brain MRI and (1)H-MRS exams at 3 Tesla. Concentrations of glutamate (Glu), glutamate + glutamine (Glx), creatine (Cr), N-Acetyl-aspartate (NAA), N-Acetyl-aspartate + N-acetylaspartylglutamate (total NAA), choline-containing compounds (Cho) and myoinositol (MI) were determined. Moreover, anxiety and depressive symptoms were evaluated with the State-Trait Anxiety Inventory (STAI) and the Beck Depression Inventory-II (BDI-II) test, respectively. CS patients had lower concentrations of glutamate and total NAA in the vmPFC than healthy controls (8.6 ± 1.2 vs. 9.3 ± 0.7 mmol/L, and 6.4 ± 0.8 vs. 6.8 ± 0.4 mmol/L, respectively; p < 0.05). Duration of hypercortisolism was negatively correlated with total NAA (r = -0.488, p < 0.05). Moreover, the concentration of total NAA was negatively correlated with anxiety state (r = -0.359, p < 0.05). Brain metabolites are abnormal in the vmPFC of patients with CS. Decreased total NAA and glutamate concentrations indicate neuronal dysfunction that appear to be related with duration of hypercortisolism and anxiety.

Amino acid metabolic processes in the temporal lobes assessed by proton magnetic resonance spectroscopy (1H MRS) in children with Down syndrome.

PubMed

Śmigielska-Kuzia, Joanna; Boćkowski, Leszek; Sobaniec, Wojciech; Kułak, Wojciech; Sendrowski, Krzysztof

2010-01-01

Down syndrome (DS), or trisomy 21, is one of the most common autosomal mutations. The overexpression of the β-amyloid precursor protein gene, located on chromosome 21, causes an increased production of the specific amyloid. The current study is a continuation of our earlier investigations relating to the profile of metabolic changes in the frontal lobes of DS patients as assessed by proton magnetic resonance spectroscopy ((1)H MRS). The aims of the study were the morphological assessment of the brain using magnetic resonance imaging (MRI) and the evaluation of metabolic disorders of the temporal lobes using (1)H MRS in DS children. The study group included 20 children with DS aged 3-15 years and treated in the Department of Pediatric Neurology and Rehabilitation, Medical University of Białystok. The control group included healthy children (n = 20). MRI scans of the heads of DS children were performed using a 1.5 T MR scanner under standard conditions. (1)H MRS investigations were also carried out to assess metabolic changes in the temporal lobes. Metabolites, such as N-acetylaspartate (NAA), glutamate-glutamine complex (Glx), choline (Cho), myoinositol (mI) and γ-aminobutyric acid (GABA), were determined in both temporal lobes with reference to the internal marker creatine (Cr). Results were compared with the control group.We found a statistically significant decrease in NAA/Cr, Cho/Cr, mI/Cr and GABA/Cr ratios. The Glx/Cr ratio in both temporal lobes of DS patients did not differ from the control group. Our results indicate metabolic neurotransmitter disorders in the central nervous system in children with DS.

γγ coincidence spectrometer for instrumental neutron-activation analysis

NASA Astrophysics Data System (ADS)

Tomlin, B. E.; Zeisler, R.; Lindstrom, R. M.

2008-05-01

Neutron-activation analysis (NAA) is an important technique for the accurate and precise determination of trace and ultra-trace elemental compositions. The application of γγ coincidence counting to NAA in order to enhance specificity was first explored over 40 years ago but has not evolved into a regularly used technique. A γγ coincidence spectrometer has been constructed at the National Institute of Standards and Technology, using two HPGe γ-ray detectors and an all-digital data-acquisition system, for the purpose of exploring coincidence NAA and its value in characterizing reference materials. This paper describes the initial evaluation of the quantitative precision of coincidence counting versus singles spectrometry, based upon a sample of neutron-irradiated bovine liver material.

Elemental analysis by IBA and NAA — A critical comparison

NASA Astrophysics Data System (ADS)

Watterson, J. I. W.

1988-12-01

In this review neutron activation analysis (NAA) and ion beam analysis (IBA) have been compared in the context of the entire field of analytical science using the discipline of scientometrics, as developed by Braun and Lyon. This perspective on the relative achievements of the two methods is modified by considering and comparing their particular attributes and characteristics, particularly in relation to their differing degree of maturity. This assessment shows that NAA, as the more mature method, is the most widely applied nuclear technique, but the special capabilities of IBA give it the ability to provide information about surface composition and elemental distribution that is unique, while it is still relatively immature and it is not yet possible to define its ultimate role with any confidence.

Metabolic Acetate Therapy for the Treatment of Traumatic Brain Injury

PubMed Central

Arun, Peethambaran; Ariyannur, Prasanth S.; Moffett, John R.; Xing, Guoqiang; Hamilton, Kristen; Grunberg, Neil E.; Ives, John A.

2010-01-01

Abstract Patients suffering from traumatic brain injury (TBI) have decreased markers of energy metabolism, including N-acetylaspartate (NAA) and ATP. In the nervous system, NAA-derived acetate provides acetyl-CoA required for myelin lipid synthesis. Acetate can also be oxidized in mitochondria for the derivation of metabolic energy. In the current study, using the controlled cortical impact model of TBI in rats, we investigated the effects of the hydrophobic acetate precursor, glyceryltriacetate (GTA), as a method of delivering metabolizable acetate to the injured brain. We found that GTA administration significantly increased the levels of both NAA and ATP in the injured hemisphere 4 and 6 days after injury, and also resulted in significantly improved motor performance in rats 3 days after injury. PMID:19803785

Metabolic acetate therapy for the treatment of traumatic brain injury.

PubMed

Arun, Peethambaran; Ariyannur, Prasanth S; Moffett, John R; Xing, Guoqiang; Hamilton, Kristen; Grunberg, Neil E; Ives, John A; Namboodiri, Aryan M A

2010-01-01

Patients suffering from traumatic brain injury (TBI) have decreased markers of energy metabolism, including N-acetylaspartate (NAA) and ATP. In the nervous system, NAA-derived acetate provides acetyl-CoA required for myelin lipid synthesis. Acetate can also be oxidized in mitochondria for the derivation of metabolic energy. In the current study, using the controlled cortical impact model of TBI in rats, we investigated the effects of the hydrophobic acetate precursor, glyceryltriacetate (GTA), as a method of delivering metabolizable acetate to the injured brain. We found that GTA administration significantly increased the levels of both NAA and ATP in the injured hemisphere 4 and 6 days after injury, and also resulted in significantly improved motor performance in rats 3 days after injury.

Maturation of limbic regions in Asperger syndrome: a preliminary study using proton magnetic resonance spectroscopy and structural magnetic resonance imaging.

PubMed

O'Brien, Finian M; Page, Lisa; O'Gorman, Ruth L; Bolton, Patrick; Sharma, Ajay; Baird, Gillian; Daly, Eileen; Hallahan, Brian; Conroy, Ronán M; Foy, Catherine; Curran, Sarah; Robertson, Dene; Murphy, Kieran C; Murphy, Declan G M

2010-11-30

People with autistic spectrum disorders (ASD, including Asperger syndrome) may have developmental abnormalities in the amygdala-hippocampal complex (AHC). However, in vivo, age-related comparisons of both volume and neuronal integrity of the AHC have not yet been carried out in people with Asperger syndrome (AS) versus controls. We compared structure and metabolic activity of the right AHC of 22 individuals with AS and 22 healthy controls aged 10-50 years and examined the effects of age between groups. We used structural magnetic resonance imaging (sMRI) to measure the volume of the AHC, and magnetic resonance spectroscopy ((1)H-MRS) to measure concentrations of N-acetyl aspartate (NAA), creatine+phosphocreatine (Cr+PCr), myo-inositol (mI) and choline (Cho). The bulk volume of the amygdala and the hippocampus did not differ significantly between groups, but there was a significant difference in the effect of age on the hippocampus in controls. Compared with controls, young (but not older) people with AS had a significantly higher AHC concentration of NAA and a significantly higher NAA/Cr ratio. People with AS, but not controls, had a significant age-related reduction in NAA and the NAA/Cr ratio. Also, in people with AS, but not controls, there was a significant relationship between concentrations of choline and age so that choline concentrations reduced with age. We therefore suggest that people with AS have significant differences in neuronal and lipid membrane integrity and maturation of the AHC. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Lower Choline-Containing Metabolites/Creatine (Cr) Rise and Failure to Sustain NAA/Cr Levels in the Dorsolateral Prefrontal Cortex Are Associated with Depressive Episode Recurrence under Maintenance Therapy: A Proton Magnetic Resonance Spectroscopy Retrospective Cohort Study.

PubMed

Henigsberg, Neven; Šarac, Helena; Radoš, Marko; Radoš, Milan; Ozretić, David; Foro, Tamara; Erdeljić Turk, Viktorija; Hrabač, Pero; Bajs Janović, Maja; Rak, Benedict; Kalember, Petra

2017-01-01

The aim of this study was to evaluate the relationship between changes in proton magnetic resonance spectroscopy (1H-MRS) parameters at the start of the index episode recovery phase and at recurrence in patients with recurrent depression who were treated with prolonged maintenance therapy. 1H-MRS parameters were analyzed in 48 patients with recurrent depression who required maintenance therapy with antidepressant medication prescribed by a psychiatrist and who continued with the same antidepressant during the maintenance phase, either to recurrence of depression, completion of the 10-year observation period, or the start of the withdrawal phase (tapering-off antidepressant). N-acetylaspartate (NAA), choline-containing metabolites (Cho), creatine (Cr), and glutamine/glutamate were measured at the start of the recovery phase and 6 months later. Recurrent depressive episodes occurred in 20 patients. These individuals had a smaller increase in Cho/Cr after the beginning of the recovery phase compared to the non-recurrent patient group and also exhibited a decreased NAA/Cr ratio. Sustainable NAA and increased Cho levels at the onset of the recovery phase of the index episode are early markers of antidepressant effectiveness associated with a lower risk of major depressive disorder recurrence. The NAA and Cho changes in the non-recurrent group may be attributable to increased brain resilience, contrary to the transient temporal effect observed in subjects who experienced a depressive episode.

A pilot study of hippocampal volume and N-acetylaspartate (NAA) as response biomarkers in riluzole-treated patients with GAD.

PubMed

Abdallah, Chadi G; Coplan, Jeremy D; Jackowski, Andrea; Sato, João R; Mao, Xiangling; Shungu, Dikoma C; Mathew, Sanjay J

2013-04-01

Anxiolytic benefit following chronic treatment with the glutamate modulating agent riluzole in patients with generalized anxiety disorder (GAD) was previously associated with differential changes in hippocampal NAA concentrations. Here, we investigated the association between hippocampal volume and hippocampal NAA in the context of riluzole response in GAD. Eighteen medication-free adult patients with GAD received 8-week of open-label riluzole. Ten healthy subjects served as a comparison group. Participants underwent magnetic resonance imaging and spectroscopy at baseline and at the end of Week 8. GAD patients who completed all interventions were classified as remitters (n=7) or non-remitters (n=6), based on final Hamilton Anxiety Rating Scale (HAM-A) scores ≤7. At baseline, GAD patients had a significant reduction in total hippocampal volume compared to healthy subjects (F(1,21)=6.55, p=0.02). This reduction was most pronounced in the remitters, compared to non-remitters and healthy subjects. Delta (final-baseline) hippocampal volume was positively correlated with delta NAA in GAD. This positive association was highly significant in the right hippocampus in GAD [r=0.81, p=0.002], with no significant association in healthy subjects [Fisher r-to-z p=0.017]. Across all GAD patients, delta hippocampal volume was positively associated with improvement in HAM-A (rspearman=0.62, p=0.03). These preliminary findings support hippocampal NAA and volume as neural biomarkers substantially associated with therapeutic response to a glutamatergic drug. Copyright © 2012 Elsevier B.V. and ECNP. All rights reserved.

Proton MRS may predict AED response in patients with TLE.

PubMed

Campos, Bruno A G; Yasuda, Clarissa L; Castellano, Gabriela; Bilevicius, Elizabeth; Li, Li M; Cendes, Fernando

2010-05-01

To compare relative N-acetylaspartate (NAA) measurements in temporal lobe epilepsy (TLE) patients with good response to the first trial of antiepileptic drugs (AEDs) (an important prognostic factor) to TLE patients who failed the first AED monotherapy and required further AED trials with monotherapy or polytherapy. We studied 25 consecutive TLE patients who responded to first AED (responders) and 21 who did not (failure-group), as well as 27 controls. Patients were seen regularly in our Epilepsy Service and underwent electroencephalography (EEG) investigation, high-resolution magnetic resonance imaging (MRI), and single-voxel proton MR spectroscopy. Voxels were tailored to the medial temporal region on each side and involved the anterior hippocampus. Analysis of variance (ANOVA) demonstrated significant variation of NAA/creatine (NAA/Cr) values in both hippocampi, ipsilateral and contralateral to the EEG focus (p < 0.001 and p = 0.021) across the groups. Pairwise post hoc comparisons showed reduced NAA/Cr in both hippocampi of failure-group compared to controls (p < 0.001) and compared to responders (p < 0.05), but not between the controls and responders. Individual analyses showed NAA/Cr ratios lower than 2 SDs (standard deviations) below the mean of controls in 9 of 21 patients (42.8%) in the failure-group (6 with unilateral and 3 with bilateral reduction) but in none of the responders. These results indicate that patients with TLE who respond well to the first AED have significantly less evidence of neuronal and axonal damage/dysfunction compared to those who are refractory to the first AED trial.

Determination of minor and trace elements concentration in kidney stones using elemental analysis techniques

NASA Astrophysics Data System (ADS)

Srivastava, Anjali

The determination of accurate material composition of a kidney stone is crucial for understanding the formation of the kidney stone as well as for preventive therapeutic strategies. Radiations probing instrumental activation analysis techniques are excellent tools for identification of involved materials present in the kidney stone. The X-ray fluorescence (XRF) and neutron activation analysis (NAA) experiments were performed and different kidney stones were analyzed. The interactions of X-ray photons and neutrons with matter are complementary in nature, resulting in distinctly different materials detection. This is the first approach to utilize combined X-ray fluorescence and neutron activation analysis for a comprehensive analysis of the kideny stones. Presently, experimental studies in conjunction with analytical techniques were used to determine the exact composition of the kidney stone. The use of open source program Python Multi-Channel Analyzer was utilized to unfold the XRF spectrum. A new type of experimental set-up was developed and utilized for XRF and NAA analysis of the kidney stone. To verify the experimental results with analytical calculation, several sets of kidney stones were analyzed using XRF and NAA technique. The elements which were identified from XRF technique are Br, Cu, Ga, Ge, Mo, Nb, Ni, Rb, Se, Sr, Y, Zr. And, by using Neutron Activation Analysis (NAA) are Au, Br, Ca, Er, Hg, I, K, Na, Pm, Sb, Sc, Sm, Tb, Yb, Zn. This thesis presents a new approach for exact detection of accurate material composition of kidney stone materials using XRF and NAA instrumental activation analysis techniques.

Extended findings of Brain Metabolite Normalization in MA-Dependent Subjects Across Sustained Abstinence: A Proton MRS Study

PubMed Central

Salo, Ruth; Buonocore, Michael H.; Leamon, Martin; Natsuaki, Yutaka; Waters, Christy; Moore, Charles D.; Galloway, Gantt P.; Nordahl, Thomas E.

2010-01-01

Objective The goal of the present study was to extend our previous findings on long-term methamphetamine (MA) use and drug abstinence on brain metabolite levels in an expanded group of MA-dependent individuals. Methods Seventeen MA abusers with sustained drug abstinence (1 year to 5 years), 30 MA abusers with short-term drug abstinence (1 month to 6 months) and 24 non-substance using controls were studied using MR spectroscopy (MRS). MRS measures of NAA/Cr, Cho/Cr and Cho/NAA were obtained in the anterior cingulate cortex (ACC) and in the primary visual cortex (PVC). Results ACC-Cho/NAA values were abnormally high in the short-term abstinent group compared to controls [F(1,52)=18.76, p<0.0001]. No differences were observed between controls and the long-term abstinent group [F(1,39)=0.97, p=0.97]. New evidence of lower ACC-NAA/Cr levels were observed in the short-term abstinent MA abusers compared to controls [F(1,52)=23.05, p<0.0001] and long-term abstinent MA abusers [F(1,45)=7.06, p=0.01]. No differences were observed between long-term abstinent MA abusers and controls [F(1,39)=0.48, p=0.49]. Conclusions The new findings of relative NAA/Cr normalization across periods of abstinence suggest that adaptive changes following cessation of MA abuse may be broader than initially thought. These changes may contribute to some degree of normalization of neuronal function in the ACC. PMID:20739127

1H-MRS in autism spectrum disorders: a systematic meta-analysis.

PubMed

Ipser, Jonathan C; Syal, Supriya; Bentley, Judy; Adnams, Colleen M; Steyn, Bennie; Stein, Dan J

2012-09-01

We conducted a systematic review and meta-analysis of proton magnetic resonance spectroscopy (1H-MRS) studies comparing autism spectrum disorder (ASD) patients with healthy controls, with the aim of profiling ASD-associated changes in the metabolites N-acetyl-aspartate (NAA) and Creatine (Cr). Meta-regression models of NAA and Cr levels were employed, using data from 20 eligible studies (N = 852), to investigate age-dependent differences in both global brain and region-specific metabolite levels, while controlling for measurement method (Cr-ratio versus absolute concentrations). Decreased NAA concentrations that were specific to children were found for whole-brain grey and white matter. In addition, a significant decrease in NAA was evident across age categories in the parietal cortex, the cerebellum, and the anterior cingulate cortex. Higher levels of Cr were observed for ASD adults than children in global grey matter, with specific increases for adults in the temporal lobe and decreased Cr in the occipital lobe in children. No differences were found for either NAA or Cr in the frontal lobes. These data provide some evidence that ASD is characterized by age-dependent fluctuations in metabolite levels across the whole brain and at the level of specific regions thought to underlie ASD-associated behavioural and affective deficits. Differences in Cr as a function of age and brain region suggests caution in the interpretation of Cr-based ratio measures of metabolites. Despite efforts to control for sources of heterogeneity, considerable variability in metabolite levels was observed in frontal and temporal regions, warranting further investigation.

Association between prefrontal N-acetylaspartate and insight in psychotic disorders.

PubMed

Larabi, Daouia I; Liemburg, Edith J; Pijnenborg, Gerdina H M; Sibeijn-Kuiper, Anita; de Vos, Annerieke E; Bais, Leonie; Knegtering, Henderikus; Ćurčić-Blake, Branislava; Aleman, André

2017-01-01

Insight is impaired in most patients with psychosis and has been associated with poorer prognosis. The exact neural basis of impaired insight is still unknown, but it may involve disrupted prefrontal neural connectivity. Numerous studies have indeed found white matter (WM) abnormalities in psychosis. The association between prefrontal WM abnormalities and insight has not been studied yet by means of proton magnetic resonance spectroscopy ( 1 H-MRS). 1 H-MRS can be used to measure N-acetylaspartate (NAA), which is considered to be a marker of neuronal integrity. We measured insight with the Birchwood Insight Scale (BIS) as well as item G12 of the Positive and Negative Syndrome Scale (PANSS) in 88 patients with psychosis. Prefrontal WM concentrations of NAA and ratios of NAA to creatine (Cr) were assessed with 1 H-MRS. Nonparametric partial correlational analyses were conducted between NAA concentrations and insight controlling for illness duration, standardized antipsychotic dose, symptom scores, voxel grey matter content and voxel cerebrospinal fluid content. We found a significant correlation between reduced NAA/Cr ratios and poorer insight as measured with the BIS, which remained significant after additional correction for full width at half maximum, signal/noise and age. This is the first study reporting a relationship between lower prefrontal concentrations of a marker of neuronal integrity and impaired insight, providing further evidence that prefrontal pathology may play an important role in impaired insight in psychosis. This may be explained by the involvement of the prefrontal cortex in several executive and metacognitive functions, such as cognitive flexibility and perspective taking. Copyright © 2016 Elsevier B.V. All rights reserved.

Aerobic fitness and the brain: increased N-acetyl-aspartate and choline concentrations in endurance-trained middle-aged adults.

PubMed

Gonzales, Mitzi M; Tarumi, Takashi; Kaur, Sonya; Nualnim, Nantinee; Fallow, Bennett A; Pyron, Martha; Tanaka, Hirofumi; Haley, Andreana P

2013-01-01

Engagement in regular aerobic exercise is associated with cognitive benefits, but information on the mechanisms governing these changes in humans is limited. The goal of the current study was to compare neurometabolite concentrations relating to cellular metabolism, structure, and viability in endurance-trained and sedentary middle-aged adults. Twenty-eight endurance-trained and 27 sedentary adults, aged 40-65 years, underwent general health assessment, cardiorespiratory fitness measurement, neuropsychological testing, and proton magnetic resonance spectroscopy ((1)H MRS). (1)H MRS was used to examine N-acetyl-aspartate (NAA), creatine (Cr), myo-inositol (mI), choline (Cho), and glutamate (Glu) concentrations in frontal and occipitoparietal grey matter. Group differences in concentrations of NAA, Cho, mI, and Glu, calculated as ratios over Cr, were explored using ANOVA. There were no significant differences in global cognitive function, memory, and executive function performance between the groups. In comparison to sedentary adults, the endurance-trained group displayed significantly higher NAA/Cr in the frontal grey matter (F(1, 53) = 5.367, p = 0.024) and higher Cho/Cr in the occipitoparietal grey matter (F(1, 53) = 5.138, p = 0.028). Within our middle-aged sample, endurance-trained adults demonstrated higher levels of NAA/Cr in the frontal grey matter and higher Cho/Cr in the occipitoparietal grey matter. Higher levels of NAA may indicate greater neuronal integrity and higher cerebral metabolic efficiency in association with cardiorespiratory fitness, whereas increased Cho may represent increased phospholipid levels secondary to neural plasticity.

Differences in iron concentration in whole blood of animal models using NAA

NASA Astrophysics Data System (ADS)

Bahovschi, V.; Zamboni, C. B.; Lopes Silva, L. F. F.; Metairon, S.; Medeiros, I. M. M. A.

2015-07-01

In this study Neutron Activation Analysis technique (NAA) was applied to determine Fe concentration in whole blood samples of several animal models such as: mice (Mus musculus), Golden Hamster (Mesocricetus auratus), Wistar rats, Albinic Rabbits of New Zealand, Golden Retriever dogs and Crioulabreed horses. These results were compared with human whole blood estimation to check their similarities.

Spectroscopic Axonal Damage of the Right Locus Coeruleus Relates to Selective Attention Impairment in Early Stage Relapsing-Remitting Multiple Sclerosis

ERIC Educational Resources Information Center

Gadea, Marien; Martinez-Bisbal, M. Carmen; Marti-Bonmati, Luis; Espert, Raul; Casanova, Bonaventura; Coret, Francisco; Celda, Bernardo

2004-01-01

Lower levels of N-acetylaspartate (NAA), a marker of axonal damage, have been found in the normal-appearing white matter (NAWM) of relapsing-remitting multiple sclerosis (RRMS) patients with low physical disability. However, its relation to the clinical status of these patients remains unclear. We explored the association between NAA levels…

Sample registration software for process automation in the Neutron Activation Analysis (NAA) Facility in Malaysia nuclear agency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rahman, Nur Aira Abd, E-mail: nur-aira@nuclearmalaysia.gov.my; Yussup, Nolida; Ibrahim, Maslina Bt. Mohd

Neutron Activation Analysis (NAA) had been established in Nuclear Malaysia since 1980s. Most of the procedures established were done manually including sample registration. The samples were recorded manually in a logbook and given ID number. Then all samples, standards, SRM and blank were recorded on the irradiation vial and several forms prior to irradiation. These manual procedures carried out by the NAA laboratory personnel were time consuming and not efficient. Sample registration software is developed as part of IAEA/CRP project on ‘Development of Process Automation in the Neutron Activation Analysis (NAA) Facility in Malaysia Nuclear Agency (RC17399)’. The objective ofmore » the project is to create a pc-based data entry software during sample preparation stage. This is an effective method to replace redundant manual data entries that needs to be completed by laboratory personnel. The software developed will automatically generate sample code for each sample in one batch, create printable registration forms for administration purpose, and store selected parameters that will be passed to sample analysis program. The software is developed by using National Instruments Labview 8.6.« less

Early life socioeconomic status, chronic physiological stress and hippocampal N-acetyl aspartate concentrations.

PubMed

McLean, John; Krishnadas, Rajeev; Batty, G David; Burns, Harry; Deans, Kevin A; Ford, Ian; McConnachie, Alex; McGinty, Agnes; McLean, Jennifer S; Millar, Keith; Sattar, Naveed; Shiels, Paul G; Tannahill, Carol; Velupillai, Yoga N; Packard, Chris J; Condon, Barrie R; Hadley, Donald M; Cavanagh, Jonathan

2012-12-01

Early life socioeconomic deprivation has been associated with cognitive and behavioural changes that persist through towards adulthood. In this study, we investigated whether early life socioeconomic status is associated with changes in the hippocampus N-acetyl aspartate (NAA), using the non-invasive technique of magnetic resonance spectroscopy (MRS). We performed proton magnetic resonance spectroscopy ((1)H-MRS) of the hippocampus at 3T in 30 adult males, selected from the PSOBID cohort. We conducted multiple regression analysis to examine the relationship between early socioeconomic status (SES) and concentration of N-acetyl-aspartate in the hippocampus. We also examined whether the relationship between these variables was mediated by markers of chronic physiological stress. Greater socioeconomic deprivation was associated with lower hippocampal NAA concentrations bilaterally. The relationship between early life SES and hippocampal NAA concentrations was mediated by allostatic load index - a marker of chronic physiological stress. Greater early life socioeconomic deprivation was associated with lower concentrations of NAA reflecting lesser neuronal integrity. This relationship was mediated by greater physiological stress. Further work, to better understand the biological processes underlying the effects of poverty, physiological stress on hippocampal metabolites is necessary. Copyright © 2012 Elsevier B.V. All rights reserved.

Design and optimization of aspartate N-acetyltransferase inhibitors for the potential treatment of Canavan disease.

PubMed

Thangavelu, Bharani; Mutthamsetty, Vinay; Wang, Qinzhe; Viola, Ronald E

2017-02-01

Canavan disease is a fatal neurological disorder caused by defects in the metabolism of N-acetyl-l-aspartate (NAA). Recent work has shown that the devastating symptoms of this disorder are correlated with the elevated levels of NAA observed in these patients, caused as a consequence of the inability of mutated forms of aspartoacylase to adequately catalyze its breakdown. The membrane-associated enzyme responsible for the synthesis of NAA, aspartate N-acetyltransferase (ANAT), has recently been purified and examined (Wang et al., Prot Expr Purif. 2016;119:11). With the availability, for the first time, of a stable and soluble form of ANAT we can now report the identification of initial inhibitors against this biosynthetic enzyme, obtained from the screening of several focused compound libraries. Two core structures of these moderate binding compounds have subsequently been optimized, with the most potent inhibitors in these series possessing sub-micromolar inhibition constants (K i values) against ANAT. Slowing the production of NAA via the inhibition of ANAT will lower the elevated levels of this metabolite and can potentially serve as a treatment option to moderate the symptoms of Canavan disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

Integrative Network-based Analysis of Magnetic Resonance Spectroscopy and Genome Wide Expression in Glioblastoma multiforme

PubMed Central

Heiland, Dieter Henrik; Mader, Irina; Schlosser, Pascal; Pfeifer, Dietmar; Carro, Maria Stella; Lange, Thomas; Schwarzwald, Ralf; Vasilikos, Ioannis; Urbach, Horst; Weyerbrock, Astrid

2016-01-01

The goal of this study was to identify correlations between metabolites from proton MR spectroscopy and genetic pathway activity in glioblastoma multiforme (GBM). Twenty patients with primary GBM were analysed by short echo-time chemical shift imaging and genome-wide expression analyses. Weighed Gene Co-Expression Analysis was used for an integrative analysis of imaging and genetic data. N-acetylaspartate, normalised to the contralateral healthy side (nNAA), was significantly correlated to oligodendrocytic and neural development. For normalised creatine (nCr), a group with low nCr was linked to the mesenchymal subtype, while high nCr could be assigned to the proneural subtype. Moreover, clustering of normalised glutamine and glutamate (nGlx) revealed two groups, one with high nGlx being attributed to the neural subtype, and one with low nGlx associated with the classical subtype. Hence, the metabolites nNAA, nCr, and nGlx correlate with a specific gene expression pattern reflecting the previously described subtypes of GBM. Moreover high nNAA was associated with better clinical prognosis, whereas patients with lower nNAA revealed a shorter progression-free survival (PFS). PMID:27350391

Systemic control of cell division and endoreduplication by NAA and BAP by modulating CDKs in root tip cells of Allium cepa.

PubMed

Tank, Jigna G; Thaker, Vrinda S

2014-01-01

Molecular mechanism regulated by auxin and cytokinin during endoreduplication, cell division, and elongation process is studied by using Allium cepa roots as a model system. The activity of CDK genes modulated by auxin and cytokinin during cell division, elongation, and endoreduplication process is explained in this research work. To study the significance of auxin and cytokinin in the management of cell division and endoreduplication process in plant meristematic cells at molecular level endoreduplication was developed in root tips of Allium cepa by giving colchicine treatment. There were inhibition of vegetative growth, formation of c-tumor at root tip, and development of endoreduplicated cells after colchicine treatment. This c-tumor was further treated with NAA and BAP to reinitiate vegetative growth in roots. BAP gave positive response in reinitiation of vegetative growth of roots from center of c-tumor. However, NAA gave negative response in reinitiation of vegetative growth of roots from c-tumor. Further, CDKs gene expression analysis from normal, endoreduplicated, and phytohormone (NAA or BAP) treated root tip was done and remarkable changes in transcription level of CDK genes in normal, endoreduplicated, and phytohormones treated cells were observed.

Elaboration and characterization of solid materials of types zeolite NaA and faujasite NaY exchanged by zinc metallic ions Zn2+

NASA Astrophysics Data System (ADS)

Nibou, D.; Amokrane, S.; Mekatel, H.; Lebaili, N.

2009-11-01

The present work deals with the elaborated of NaA and faujasite NaY solid materials according to a hydrothermal crystallization of amorphous gels composed of solutions of silicon, aluminum and sodium. The process elaboration has been achieved in autoclaves made of steel lined in Teflon under different operating conditions of temperature of heating, time of contact and stirring. After crystallization, the samples were characterized by different techniques such as X ray diffraction, scanning electronic microscopy, infrared spectroscopy, thermal analysis, and chemical analysis. Pure solid materials NaA and NaY zeolites were obtained and were impregnated by (Zn2+) ions by ion exchange process. The effects of various parameters such as initial metal concentration, pH, solid-liquid ratio (R) and temperature on the exchange percentage are studied. The equilibrium isotherms of zinc ions sorption are also evaluated using Langmuir and Freundlich models. Thermodynamic parameters, i.e. enthalpy of adsorption ΔHads∘, entropy change ΔSads∘ and Gibbs free energy ΔGads∘ for the sorption of zinc ions on NaA and NaY zeolites were examined.

Systemic Control of Cell Division and Endoreduplication by NAA and BAP by Modulating CDKs in Root Tip Cells of Allium cepa

PubMed Central

Tank, Jigna G.; Thaker, Vrinda S.

2014-01-01

Molecular mechanism regulated by auxin and cytokinin during endoreduplication, cell division, and elongation process is studied by using Allium cepa roots as a model system. The activity of CDK genes modulated by auxin and cytokinin during cell division, elongation, and endoreduplication process is explained in this research work. To study the significance of auxin and cytokinin in the management of cell division and endoreduplication process in plant meristematic cells at molecular level endoreduplication was developed in root tips of Allium cepa by giving colchicine treatment. There were inhibition of vegetative growth, formation of c-tumor at root tip, and development of endoreduplicated cells after colchicine treatment. This c-tumor was further treated with NAA and BAP to reinitiate vegetative growth in roots. BAP gave positive response in reinitiation of vegetative growth of roots from center of c-tumor. However, NAA gave negative response in reinitiation of vegetative growth of roots from c-tumor. Further, CDKs gene expression analysis from normal, endoreduplicated, and phytohormone (NAA or BAP) treated root tip was done and remarkable changes in transcription level of CDK genes in normal, endoreduplicated, and phytohormones treated cells were observed. PMID:24955358

Comparison of somatic embryogenesis in Medicago sativa and Medicago truncatula.

PubMed

Hoori, F; Ehsanpour, A A; Mostajeran, A

2007-02-01

In this study, the regeneration through embryogenesis of two species of Medicago were studied. Seeds of Medicago sativa cv. Rehnani and M. truncatula line A17 were grown on MS medium. After 4-6 weeks, segments of leaf and stem from two species were transferred to MS medium containing 2 mg L(-1) NAA, 2,4-D and Kinetin. The results indicated that callus formation from leaf explants of M. sativa was higher than M. trancatula. In the next stage, media with different combinations of auxin, cytokinin or ethinyl estradiol were provided for regeneration. Then in two stages, explants of leaf and stem of two species were transferred on these media. Results after 3-6 weeks showed that in medium containing NAA and TDZ, stem pieces ofM. sativa produced shoots while leaf pieces on NAA and ethinyl estradiol formed roots. Leaf explants of M. truncatula in the medium containing NAA and BAP, produced somatic embryos. Also in media with auxin and ethinyl estradiol, somatic embryos were formed on calli of two species. Ethinyl estradiol and auxin together can induce somatic embryogenesis and root production on calli and stem or leaf explants.

Subfield-specific loss of hippocampal N-acetyl aspartate in temporal lobe epilepsy.

PubMed

Vielhaber, Stefan; Niessen, Heiko G; Debska-Vielhaber, Grazyna; Kudin, Alexei P; Wellmer, Jörg; Kaufmann, Jörn; Schönfeld, Mircea Ariel; Fendrich, Robert; Willker, Wieland; Leibfritz, Dieter; Schramm, Johannes; Elger, Christian E; Heinze, Hans-Jochen; Kunz, Wolfram S

2008-01-01

In patients with mesial temporal lobe epilepsy (MTLE) it remains an unresolved issue whether the interictal decrease in N-acetyl aspartate (NAA) detected by proton magnetic resonance spectroscopy ((1)H-MRS) reflects the epilepsy-associated loss of hippocampal pyramidal neurons or metabolic dysfunction. To address this problem, we applied high-resolution (1)H-MRS at 14.1 Tesla to measure metabolite concentrations in ex vivo tissue slices from three hippocampal subfields (CA1, CA3, dentate gyrus) as well as from the parahippocampal region of 12 patients with MTLE. In contrast to four patients with lesion-caused MTLE, we found a large variance of NAA concentrations in the individual hippocampal regions of patients with Ammon's horn sclerosis (AHS). Specifically, in subfield CA3 of AHS patients despite of a moderate preservation of neuronal cell densities the concentration of NAA was significantly lowered, while the concentrations of lactate, glucose, and succinate were elevated. We suggest that these subfield-specific alterations of metabolite concentrations in AHS are very likely caused by impairment of mitochondrial function and not related to neuronal cell loss. A subfield-specific impairment of energy metabolism is the probable cause for lowered NAA concentrations in sclerotic hippocampi of MTLE patients.

Post‐surgical changes in brain metabolism detected by magnetic resonance spectroscopy in normal pressure hydrocephalus: results of a pilot study

PubMed Central

del Mar Matarín, María; Pueyo, Roser; Poca, María Antonia; Falcón, Carles; Mataró, María; Bargalló, Núria; Sahuquillo, Juan; Junqué, Carme

2007-01-01

Background Adult normal pressure hydrocephalus (NPH) is one of the few potentially treatable causes of dementia. Some morphological and functional abnormalities attributed to hydrocephalus improve following treatment. Objectives We focused on analysis of changes in cerebral metabolites using proton magnetic resonance spectroscopy (1H‐MRS) after NPH treatment, and its clinical and cognitive correlation. Methods 1H‐MRS, neuropsychological and clinical status examinations were performed before and 6 months after shunting in 12 adults with idiopathic NPH. We obtained N‐acetyl‐aspartate (NAA), choline (Cho), myoinositol (MI) and creatine (Cr) values. Results After surgery, NAA/Cr was significantly increased. Moreover, NAA/Cr values were related to cognitive deterioration. Conclusion MRS could be a marker of neuronal dysfunction in NPH. PMID:17299021

Abnormal Concentration of GABA and Glutamate in The Prefrontal Cortex in Schizophrenia.-An in Vivo 1H-MRS Study.

PubMed

Chen, Tianyi; Wang, Yingchan; Zhang, Jianye; Wang, Zuowei; Xu, Jiale; Li, Yao; Yang, Zhilei; Liu, Dengtang

2017-10-25

The etiology and pathomechanism of schizophrenia are unknown. The traditional dopamine (DA) hypothesis is unable to fully explain its pathology and therapeutics. The glutamate (Glu) and γ-aminobutyric acid (GABA) hypotheses suggest Glu or GABA concentrations are abnormal in the brains of patients with schizophrenia. Magnetic resonance spectroscopy (MRS) show glutamate level increases in the ventromedial prefrontal cortex (vmPFC) including the anterior cingulated cortex (ACC) in those with schizophrenia. To investigate the function of the glutamate system (glutamate and γ-aminobutyric acid) in the etiology and pathomechanism of schizophrenia. 24 drug naïve patients with schizophrenia and 24 healthy volunteers were matched by gender, age, and educational level. The Siemens 3T MRI system was used to collect the magnetic resonance spectroscopy (MRS) data of the subjects. The regions of interest included the left dorsolateral prefrontal cortex (IDLPFC), ventromedial prefrontal cortex (vmPFC), and anterior cingulate cortex (ACC). LCModel software was used to analyze the concentrations of γ-aminobutyric acid (GABA), glutamate (Glu), glutamine (Gln), N-acetylaspartate (NAA), and N-acetylaspartylglutamate (NAAG) in the region of interest. Meanwhile, the Positive and Negative Syndrome Scale (PANSS) and the Clinical Global Impression Scale (CGI) were used to assess the mental symptoms and severity of the disease. The median GABA concentrations in the anterior cingulate cortex of the schizophrenia group and the healthy control group were 1.90 (Q1=1.55, Q3=2.09) and 2.16 (Q1=1.87, Q3=2.59) respectively; the mean (sd) Glu concentrations were 6.07 (2.48) and 6.54 (1.99); the median Gln concentrations were 0.36 (Q1=0.00, Q3=0.74) and 0.29 (Q1=0.00, Q3=0.59); the between-group difference of the GABA concentrations was statistically significant ( Z =-2.95, p =0.003); the between-group difference of the GABA/(NAA+NAAG) was statistically significant ( Z =-2.72, p =0.012); the between-group difference of Glu and Gln was not statistically significant. The age of the schizophrenia group was negatively correlated with the GABA concentration in the anterior cingulate ( R =-0.494, p =0.014), and negatively correlated with GABA/ (NAA+NAAG) ( R =-0.473, p =0.020). Yet there was no such correlation in the control group. After calibration, no significant correlation was found between the clinical symptoms and the concentrations of the metabolites. The concentration of glutamate in the vemtromedial prefrontal cortex of patients with schizophrenia was abnormal, whereas the concentration of GABA in the anterior cingulate cortex decreased, supporting the hypothesis of abnormal glutamate -GABA in the brains of those individuals with schizophrenia. In patients with schizophrenia, the GABA in the anterior cingulate cortex had an accelerated decline with age. The clinical symptoms may be correlated to the metabolite concentration of the anterior cingulate cortex.

Cell wall invertase in tobacco crown gall cells : enzyme properties and regulation by auxin.

PubMed

Weil, M; Rausch, T

1990-12-01

The cell wall invertase from an Agrobacterium tumefaciens-transformed Nicotiana tabacum cell line (SR1-C58) was purified. The heterogeneously glycosylated enzyme has the following properties: M(r) 63,000, pH optimum at 4.7, K(m sucrose) 0.6 millimolar (at pH 4.7), pl 9.5. Enzyme activity is inhibited by micromolar concentrations of HgCl(2) but is insensitive to H(2)O(2), N-ethylmaleimide and dithiothreitol. Upon transfer of transformed cells from the stationary phase to fresh medium, a cycloheximide- and tunicamycin-sensitive de novo formation of cell wall invertase is demonstrated in the absence or presence of sucrose. While in an auxin mutant (lacking gene 1;SR1-3845) 1 micromolar 1-naphthaleneacetic acid led to a further increased activity, the wild-type transformed cell line (SR1-C58) responded with a decreased activity compared to the control. An analysis of cell wall invertase in and around tumors initiated with Agrobacterium tumefaciens (strain C58) on Nicotiana tabacum stem and Kalanchoë daigremontiana leaves revealed gradients of activity. The results indicate that the auxin-stimulated cell wall invertase is essential for the establishment of the tumor sink.

Decreased N-Acetyl Aspartate/Myo-Inositol Ratio in the Posterior Cingulate Cortex Shown by Magnetic Resonance Spectroscopy May Be One of the Risk Markers of Preclinical Alzheimer’s Disease: A 7-Year Follow-Up Study

PubMed Central

Waragai, Masaaki; Moriya, Masaru; Nojo, Takeshi

2017-01-01

Although molecular positron emission tomography imaging of amyloid and tau proteins can facilitate the detection of preclinical Alzheimer’s disease (AD) pathology, it is not useful in clinical practice. More practical surrogate markers for preclinical AD would provide valuable tools. Thus, we sought to validate the utility of conventional magnetic resonance spectroscopy (MRS) as a screening method for preclinical AD. A total of 289 older participants who were cognitively normal at baseline were clinically followed up for analysis of MRS metabolites, including N-acetyl aspartate (NAA) and myo-inositol (MI) in the posterior cingulate cortex (PCC) for 7 years. The 289 participants were retrospectively divided into five groups 7 years after baseline: 200 (69%) remained cognitively normal; 53 (18%) developed mild cognitive impairment (MCI); 21 (7%) developed AD; eight (2%) developed Parkinson’s disease with normal cognition, and seven (2%) developed dementia with Lewy bodies (DLB). The NAA/MI ratios of the PCC in the AD, MCI, and DLB groups were significantly decreased compared with participants who maintained normal cognition from baseline to 7 years after baseline. MMSE scores 7 years after baseline were significantly correlated with MI/Cr and NAA/MI ratios in the PCC. These results suggest that cognitively normal elderly subjects with low NAA/MI ratios in the PCC might be at risk of progression to clinical AD. Thus, the NAA/MI ratio in the PCC measured with conventional 1H MRS should be reconsidered as a possible adjunctive screening marker of preclinical AD in clinical practice. PMID:28968236

Prefrontal Structure Varies as a Function of Pain Symptoms in Chronic Fatigue Syndrome.

PubMed

van der Schaaf, Marieke E; De Lange, Floris P; Schmits, Iris C; Geurts, Dirk E M; Roelofs, Karin; van der Meer, Jos W M; Toni, Ivan; Knoop, Hans

2017-02-15

Chronic fatigue syndrome (CFS) is characterized by severe fatigue persisting for ≥6 months and leading to considerable impairment in daily functioning. Neuroimaging studies of patients with CFS have revealed alterations in prefrontal brain morphology. However, it remains to be determined whether these alterations are specific for fatigue or whether they relate to other common CFS symptoms (e.g., chronic pain, lower psychomotor speed, and reduced physical activity). We used magnetic resonance imaging to quantify gray matter volume (GMV) and the N-acetylaspartate and N-acetylaspartylglutamate/creatine ratio (NAA/Cr) in a group of 89 women with CFS. Building on previous reports, we tested whether GMV and NAA/Cr in the dorsolateral prefrontal cortex are associated with fatigue severity, pain, psychomotor speed, and physical activity, while controlling for depressive symptoms. We also considered GMV and NAA/Cr differences between patients with CFS and 26 sex-, age-, and education-matched healthy controls. The presence of pain symptoms was the main predictor of both GMV and NAA/Cr in the left dorsolateral prefrontal cortex of patients with CFS. More pain was associated with reduced GMVs and NAA/Cr, over and above the effects of fatigue, depressive symptoms, physical activity, and psychomotor speed. In contrast to previous reports and despite a large representative sample, global GMV did not differ between the CFS and healthy control groups. CFS, as diagnosed by Centers for Disease Control and Prevention criteria, is not a clinical entity reliably associated with reduced GMV. Individual variation in the presence of pain, rather than fatigue, is associated with neuronal alterations in the dorsolateral prefrontal cortex of patients with CFS. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Comparison of LCModel and SAGE in Analysis of Brain Metabolite Concentrations-A study of Patients with Mild Cognitive Impairment.

PubMed

Shih, Chiu-Ming; Lai, Jui-Jen; Chang, Chin-Ching; Chen, Cheng-Sheng; Yeh, Yi-Chun; Jaw, Twei-Shiun; Hsu, Jui-Sheng; Li, Chun-Wei

2017-03-15

The purpose of this study was to compare brain metabolite concentration ratios determined by LCModel and Spectroscopy Analysis by General Electric (SAGE) quantitative methods to elucidate the advantages and disadvantages of each method. A total of 10 healthy volunteers and 10 patients with mild cognitive impairment (MCI) were recruited in this study. A point-resolved spectroscopy (PRESS) sequence was used to obtain the brain magnetic resonance spectroscopy (MRS) spectra of the volunteers and patients, as well as the General Electric (GE) MRS-HD-sphere phantom. The brain metabolite concentration ratios were estimated based on the peak area obtained from both LCModel and SAGE software. Three brain regions were sampled for each volunteer or patient, and 20 replicates were acquired at different times for the phantom analysis. The metabolite ratios of the GE phantom were estimated to be myo-inositol (mI)/creatine (Cr): 0.70 ± 0.01, choline (Cho)/Cr: 0.37 ± 0.00, N-acetylaspartate (NAA)/Cr: 1.26 ± 0.02, and NAA/mI: 1.81 ± 0.04 by LCModel, and mI/Cr: 0.88 ± 0.15, Cho/Cr: 0.35 ± 0.01, NAA/Cr: 1.33 ± 0.03, and NAA/mI: 1.55 ± 0.26 by SAGE. In the healthy volunteers and MCI patients, the ratios of mI/Cr and Cho/Cr estimated by LCModel were higher than those estimated by SAGE. In contrast, the ratio of NAA/Cr estimated by LCModel was lower than that estimated by SAGE. Both methods were acceptable in estimating brain metabolite concentration ratios. However, LCModel was marginally more accurate than SAGE because of its full automation, basis set, and user independency.

Proton magnetic resonance spectroscopic findings of cerebral fat embolism induced by triolein emulsion in cats.

PubMed

Baik, S K; Kim, Y-W; Kim, H J; Lee, J W; Cho, B M; Kim, D-H; Choi, S H; Lee, S H; Chang, K H

2008-12-01

In experimental studies, embolization of the cerebral hemisphere with triolein emulsion has revealed reversible magnetic resonance imaging (MRI) findings in the subacute stage. To investigate the changes in the major metabolites, by proton magnetic resonance spectroscopy (MRS), in a cerebral fat embolism induced by a triolein emulsion. The internal carotid arteries of 19 cats were injected with a triolein emulsion, and multivoxel MRS was performed 30 min, 1 day, and 7 days later. In the control group, six cats were injected with normal saline. The MR spectra were evaluated for N-acetyl aspartate (NAA), creatine (Cr), and choline (Cho), along with the presence of lipid and lactate. Semiquantitative analyses of NAA/Cr, Cho/Cr, NAA/Cho, and lipid/Cr ratios compared the median values of the ipsilateral metabolite ratios with those of the contralateral side and in the control group for each point in time. The NAA/Cr, Cho/Cr, and NAA/Cho ratios in the ipsilateral cerebral hemisphere of the embolized group after 30 min, 1 day, and 7days were not significantly different from the contralateral hemisphere of the embolized and control groups (P>0.05). The lipid/Cr ratio in the ipsilateral cerebral hemisphere of the embolized group was significantly higher when compared with the control group (P=0.012 at 30 min, P=0.001 on day 1, and P=0.018 on day 7). Cerebral fat embolism induced by a triolein emulsion resulted in no significant change in the major metabolites of the brain in the acute stage, except for an elevated lipid/Cr ratio, which suggests the absence of any significant hypoxic-ischemic changes in the lesions embolized using a fat emulsion.

Correlation of Diffusion and Metabolic Alterations in Different Clinical Forms of Multiple Sclerosis

PubMed Central

Hannoun, Salem; Bagory, Matthieu; Durand-Dubief, Francoise; Ibarrola, Danielle; Comte, Jean-Christophe; Confavreux, Christian; Cotton, Francois; Sappey-Marinier, Dominique

2012-01-01

Diffusion tensor imaging (DTI) and MR spectroscopic imaging (MRSI) provide greater sensitivity than conventional MRI to detect diffuse alterations in normal appearing white matter (NAWM) of Multiple Sclerosis (MS) patients with different clinical forms. Therefore, the goal of this study is to combine DTI and MRSI measurements to analyze the relation between diffusion and metabolic markers, T2-weighted lesion load (T2-LL) and the patients clinical status. The sensitivity and specificity of both methods were then compared in terms of MS clinical forms differentiation. MR examination was performed on 71 MS patients (27 relapsing remitting (RR), 26 secondary progressive (SP) and 18 primary progressive (PP)) and 24 control subjects. DTI and MRSI measurements were obtained from two identical regions of interest selected in left and right centrum semioval (CSO) WM. DTI metrics and metabolic contents were significantly altered in MS patients with the exception of N-acetyl-aspartate (NAA) and NAA/Choline (Cho) ratio in RR patients. Significant correlations were observed between diffusion and metabolic measures to various degrees in every MS patients group. Most DTI metrics were significantly correlated with the T2-LL while only NAA/Cr ratio was correlated in RR patients. A comparison analysis of MR methods efficiency demonstrated a better sensitivity/specificity of DTI over MRSI. Nevertheless, NAA/Cr ratio could distinguish all MS and SP patients groups from controls, while NAA/Cho ratio differentiated PP patients from controls. This study demonstrated that diffusivity changes related to microstructural alterations were correlated with metabolic changes and provided a better sensitivity to detect early changes, particularly in RR patients who are more subject to inflammatory processes. In contrast, the better specificity of metabolic ratios to detect axonal damage and demyelination may provide a better index for identification of PP patients. PMID:22479330

Simulating the Effect of Spectroscopic MRI as a Metric for Radiation Therapy Planning in Patients with Glioblastoma

PubMed Central

Cordova, J. Scott; Kandula, Shravan; Gurbani, Saumya; Zhong, Jim; Tejani, Mital; Kayode, Oluwatosin; Patel, Kirtesh; Prabhu, Roshan; Schreibmann, Eduard; Crocker, Ian; Holder, Chad A.; Shim, Hyunsuk; Shu, Hui-Kuo

2017-01-01

Due to glioblastoma’s infiltrative nature, an optimal radiation therapy (RT) plan requires targeting infiltration not identified by anatomical magnetic resonance imaging (MRI). Here, high-resolution, whole-brain spectroscopic MRI (sMRI) is used to describe tumor infiltration alongside anatomical MRI and simulate the degree to which it modifies RT target planning. In 11 patients with glioblastoma, data from preRT sMRI scans were processed to give high-resolution, whole-brain metabolite maps normalized by contralateral white matter. Maps depicting choline to N-Acetylaspartate (Cho/NAA) ratios were registered to contrast-enhanced T1-weighted RT planning MRI for each patient. Volumes depicting metabolic abnormalities (1.5−, 1.75−, and 2.0-fold increases in Cho/NAA ratios) were compared with conventional target volumes and contrast-enhancing tumor at recurrence. sMRI-modified RT plans were generated to evaluate target volume coverage and organ-at-risk dose constraints. Conventional clinical target volumes and Cho/NAA abnormalities identified significantly different regions of microscopic infiltration with substantial Cho/NAA abnormalities falling outside of the conventional 60 Gy isodose line (41.1, 22.2, and 12.7 cm3, respectively). Clinical target volumes using Cho/NAA thresholds exhibited significantly higher coverage of contrast enhancement at recurrence on average (92.4%, 90.5%, and 88.6%, respectively) than conventional plans (82.5%). sMRI-based plans targeting tumor infiltration met planning objectives in all cases with no significant change in target coverage. In 2 cases, the sMRI-modified plan exhibited better coverage of contrast-enhancing tumor at recurrence than the original plan. Integration of the high-resolution, whole-brain sMRI into RT planning is feasible, resulting in RT target volumes that can effectively target tumor infiltration while adhering to conventional constraints. PMID:28105468

Insular cortex metabolite changes in obstructive sleep apnea.

PubMed

Yadav, Santosh K; Kumar, Rajesh; Macey, Paul M; Woo, Mary A; Yan-Go, Frisca L; Harper, Ronald M

2014-05-01

Adults with obstructive sleep apnea (OSA) show significant autonomic and neuropsychologic deficits, which may derive from damage to insular regions that serve those functions. The aim was to assess glial and neuronal status from anterior insular metabolites in OSA versus controls, using proton magnetic resonance spectroscopy (PMRS), and thus to provide insights for neuroprotection against tissue changes, and to reduce injury consequences. Cross-sectional study. University-based medical center. Thirty-six patients with OSA, 53 controls. None. We performed PMRS in bilateral anterior insulae using a 3.0-Tesla magnetic resonance imaging scanner, calculated N-acetylaspartate/creatine (NAA/Cr), choline/creatine (Cho/Cr), myo-inositol/creatine (MI/Cr), and MI/NAA metabolite ratios, and examined daytime sleepiness (Epworth Sleepiness Scale, ESS), sleep quality (Pittsburgh Sleep Quality Index, PSQI), and neuropsychologic status (Beck Depression Inventory II [BDI-II] and Beck Anxiety Inventory [BAI]). Body mass index, BAI, BDI-II, PSQI, and ESS significantly differed between groups. NAA/ Cr ratios were significantly reduced bilaterally, and left-sided MI/Cr and MI/NAA ratios were increased in OSA over controls. Significant positive correlations emerged between left insular MI/Cr ratios and apnea-hypopnea index values, right insular Cho/Cr ratios and BDI-II and BAI scores, and negative correlations appeared between left insular NAA/Cr ratios and PSQI scores and between right-side MI/Cr ratios and baseline and nadir change in O2 saturation. Adults with obstructive sleep apnea showed bilaterally reduced N-acetylaspartate and left-side increased myo-inositol anterior insular metabolites, indicating neuronal damage and increased glial activation, respectively, which may contribute to abnormal autonomic and neuropsychologic functions in the condition. The activated glial status likely indicates increased inflammatory action that may induce more neuronal injury, and suggests separate approaches for glial and neuronal protection.

Effect of Hypergravity and Phytohormones on Isoflavonoid Accumulation in Soybean ( Glycine max. L.) Callus

NASA Astrophysics Data System (ADS)

Downey, Peter J.; Levine, Lanfang H.; Musgrave, Mary E.; McKeon-Bennett, Michelle; Moane, Siobhán

2013-02-01

The objective of this study was to explore the potential interaction between gravity and growth hormones on isoflavonoid accumulation. Soybean callus ( Glycine max (L.) Merr. cv. `Acme') was grown in the dark for 16 days at 22 °C in a growth medium supplemented with four different combinations of phytohormones and subjected to 4- g and 8- g forces simulated in a centrifuge and 1- g in an adjacent stationary control. Isoflavonoid aglycones and their glycoside concentrations (daidzein, genistein, daidzin, 6″-O-malonyl-7-O-glucosyl daidzein, genistin, 6″-O-malonyl-7-O-glucosyl genistein) were determined in the resulting tissues. Although gravity had no significant impact on callus growth, increasing gravity reduced isoflavonoid accumulation in three out of the four phytohormone-supplemented culture media. The ratio of the auxin naphthalene acetic acid (NAA) to the cytokinin benzylaminopurine (BAP) was found to have profound effect on both callus growth and isoflavonoid accumulation. The cytokinin BAP promoted callus tissue growth, but reduced callus isoflavonoid suggesting the isoflavonoid accumulation was not keeping pace with the cell growth in the elevated concentration of BAP. On the other hand, NAA had little or no effect on callus growth, but greatly enhanced isoflavonoid accumulation. Interactive effects of gravity and hormone on isoflavonoid accumulation were evident and its implication to the mechanism by which gravity exerts the effect on plant secondary metabolites is discussed.

Posterior Insular Molecular Changes in Myofascial Pain

PubMed Central

Gerstner, G.E.; Gracely, R.H.; Deebajah, A.; Ichesco, E.; Quintero, A.; Clauw, D.J.; Sundgren, P.C.

2012-01-01

Temporomandibular disorders (TMD) include craniocervical pain conditions with unclear etiologies. Central changes are suspected; however, few neuroimaging studies of TMD exist. Single-voxel proton magnetic resonance spectroscopy (1H-MRS) was used before and after pressure-pain testing to assess glutamate (Glu), glutamine (Gln), N-acetylaspartate (NAA), and choline (Cho) levels in the right and left posterior insulae of 11 individuals with myofascial TMD and 11 matched control individuals. Glu levels were significantly lower in all individuals after pain testing. Among those with TMD, left-insular Gln levels were related to reported pain, left posterior insular NAA and Cho levels were significantly higher at baseline than in control individuals, and NAA levels were significantly correlated with pain-symptom duration, suggesting adaptive changes. The results suggest that significant central cellular and molecular changes can occur in individuals with TMD. PMID:22451533

Development of automation software for neutron activation analysis process in Malaysian nuclear agency

NASA Astrophysics Data System (ADS)

Yussup, N.; Rahman, N. A. A.; Ibrahim, M. M.; Mokhtar, M.; Salim, N. A. A.; Soh@Shaari, S. C.; Azman, A.

2017-01-01

Neutron Activation Analysis (NAA) process has been established in Malaysian Nuclear Agency (Nuclear Malaysia) since 1980s. Most of the procedures established especially from sample registration to sample analysis are performed manually. These manual procedures carried out by the NAA laboratory personnel are time consuming and inefficient. Hence, a software to support the system automation is developed to provide an effective method to replace redundant manual data entries and produce faster sample analysis and calculation process. This paper describes the design and development of automation software for NAA process which consists of three sub-programs. The sub-programs are sample registration, hardware control and data acquisition; and sample analysis. The data flow and connection between the sub-programs will be explained. The software is developed by using National Instrument LabView development package.

Concentration of Ca in blood of amateur runners using NAA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kovacs, L.; Zamboni, C. B.; Metairon, S.

2013-05-06

In this study the Ca levels were determined in amateur runners blood at LABEX (Laboratorio de Bioquimica do Exercicio - UNICAMP, Brazil), using Neutron Activation Analyses (NAA) technique. The range established at rest (162 - 410 mgL{sup -1}) when compared with control group (51 - 439 mgL{sup -1}) suggests that there is a dependency of these limits in the function of the adopted physical training.

A Controlled Trial of Topiramate Treatment for Alcohol Dependence in Veterans with PTSD

DTIC Science & Technology

2014-10-01

The POC has been targeted traditionally in 1H MRS studies to measure levels of the inhibitory neuro - transmitter GABA in various populations, and...further supporting evidence for group differences of neuro - transmitter levels would obviate the need for advancing targeted treatment approaches for PAUD...absolute NAA concentration), reduced NAA concentration in the ACC, and higher left hippocampal Cho/Cr. These abnormalities indicate neuro - nal injury

Proton magnetic resonance spectroscopy in obsessive-compulsive disorder: evidence for reduced neuronal integrity in the anterior cingulate.

PubMed

Tükel, Raşit; Aydın, Kubilay; Ertekin, Erhan; Özyıldırım, Seda Şahin; Taravari, Vedat

2014-12-30

Neuroimaging studies have suggested that dysfunction of the cortico-striatal-thalamo-cortical (CSTC) circuit is a key pathophysiologic feature of obsessive-compulsive disorder (OCD). Several studies using proton magnetic resonance spectroscopy ((1)H MRS) have found abnormal neural metabolite concentrations among OCD patients. The aim of this study was to investigate the metabolic integrity of the anterior cingulate, caudate and putamen in OCD. In the present study, 32 unmedicated patients with OCD, including 23 who were drug-naïve, were compared using MRS with 32 healthy controls. Metabolite levels of N-acetylaspartate (NAA), choline (Cho) and myo-inositol (mI) were measured in terms of their ratios to creatine (Cr). The ratio of NAA/Cr was significantly lower in OCD patients than in healthy controls in the anterior cingulate. There was a tendency for levels of NAA/Cr to be lower in the caudate and the putamen in patients with OCD compared with healthy controls. NAA/Cr ratios were negatively correlated with the total scores on the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) in the anterior cingulate in patients with OCD. Our results support the significance and biochemical involvement of the anterior cingulate cortex (ACC) in the pathophysiology of OCD. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Applications of XRF, NAA and low-kV radiographic techniques in the study of body composition and diseased tissue

NASA Astrophysics Data System (ADS)

Bradley, D. A.; Ng, K. H.; Green, S.; Mountford, P. J.; Shukri, A.; Evans, J.

1996-05-01

Members of this group have responded to a number of challenging health issues by attempting to devise sensitive XRF, NAA and low-kV radiographic measurement systems foboth in vivo and in vitro applications. These studies are generally either of toxicological importance, examine potential for diagnosing the presence of disease, or offer effective means for monitoring potentially harmful side-effects of therapy. Particular examples include the in vivo XRF investigation of human skeletal uptake of Pb in working and living environments, in vivo XRF monitoring of elevated levels of Fe in skin (indicating the presence of an undesirable side-effect of the treatment of thalassaemia), in vivo NAA monitoring of elevated levels of Al in bone (indicating an undesirable side-effect of the treatment of chronic renal failure) and in vitro characterization, by means of low-kV imaging, of a range of calcification parameters in healthy and diseased breast tissue. The latter investigation has been conducted in association with an in vitro NAA study of concentrations of trace elements in the same types of tissue. Figures of merit for the various measurement systems have been obtained in terms of minimum detectable levels and concentrations (MDL's and MDC's) and where applicable, image related parameters.

Trace impurities analysis of aluminum nanopowder and its air combustion product

NASA Astrophysics Data System (ADS)

Kabanov, Denis V.; Merkulov, Viktor G.; Mostovshchikov, Andrey V.; Ilyin, Alexander P.

2018-03-01

Neutron activation analysis (NAA) allows estimating micro-concentrations of chemicals and analyzes tens of elements at one measurement. In this paper we have used NAA to examine metal impurities in the electroexplosive aluminum nanopowder (ANP) and its air-combustion products produced by burning in crucibles in an electric and magnetic field and without application of fields. It has been revealed that in the air-combustion products impurities content is reduced. The presence of impurities in the ANP is associated with electric explosion technology (erosion of electrode and chamber materials) and with the previous development of various nanopowders in the composition of this electric explosive device. NAA is characterized by a high sensitivity and reproducibility to elements content and low metering error. According to the obtained results it has been concluded that NAA metering error does not exceed 10% in the wide concentration range, from 0.01 to 2100 ppm, particularly. Besides, there is high reproducibility of the method that has been proved on macro-elements of Ca (>1000 ppm), Fe (>2000 ppm), and micro-elements as Sm, U, Ce, Sb, Th, etc. (<0.9 ppm). It is recommended to use an individual unit for the production of pure metal powders for electric explosion and production of nanopowders, which is possible with mass production of nanopowders.

Cerebral white matter blood flow and energy metabolism in multiple sclerosis.

PubMed

Steen, Christel; D'haeseleer, Miguel; Hoogduin, Johannes M; Fierens, Yves; Cambron, Melissa; Mostert, Jop P; Heersema, Dorothea J; Koch, Marcus W; De Keyser, Jacques

2013-09-01

Cerebral blood flow (CBF) is reduced in normal-appearing white matter (NAWM) of subjects with multiple sclerosis (MS), but the underlying mechanism is unknown. The objective of this article is to assess the relationship between reduced NAWM CBF and both axonal mitochondrial metabolism and astrocytic phosphocreatine (PCr) metabolism. Ten healthy controls and 25 MS subjects were studied with 3 Tesla magnetic resonance imaging. CBF was measured using pseudo-continuous arterial spin labeling. N-acetylaspartate/creatine (NAA/Cr) ratios (axonal mitochondrial metabolism) were obtained using (1)H-MR spectroscopy and PCr/β-ATP ratios using (31)P-MR spectroscopy. In centrum semiovale NAWM, we assessed correlations between CBF and both NAA/Cr and PCr/β-ATP ratios. Subjects with MS had a widespread reduction in CBF of NAWM (centrum semiovale, periventricular, frontal and occipital), and gray matter (frontoparietal cortex and thalamus). Compared to controls, NAA/Cr in NAWM of the centrum semiovale of MS subjects was decreased, whereas PCr/β-ATP was increased. We found no correlations between CBF and PCr/β-ATP. CBF and NAA/Cr correlated in controls (p = 0.02), but not in MS subjects (p = 0.68). Our results suggest that in MS patients there is no relationship between reduced CBF in NAWM and impaired axonal mitochondrial metabolism or astrocytic PCr metabolism.

Energetics of sodium-calcium exchanged zeolite A.

PubMed

Sun, H; Wu, D; Guo, X; Shen, B; Navrotsky, A

2015-05-07

A series of calcium-exchanged zeolite A samples with different degrees of exchange were prepared. They were characterized by powder X-ray diffraction (XRD) and differential scanning calorimetry (DSC). High temperature oxide melt drop solution calorimetry measured the formation enthalpies of hydrated zeolites CaNa-A from constituent oxides. The water content is a linear function of the degree of exchange, ranging from 20.54% for Na-A to 23.77% for 97.9% CaNa-A. The enthalpies of formation (from oxides) at 25 °C are -74.50 ± 1.21 kJ mol(-1) TO2 for hydrated zeolite Na-A and -30.79 ± 1.64 kJ mol(-1) TO2 for hydrated zeolite 97.9% CaNa-A. Dehydration enthalpies obtained from differential scanning calorimetry are 32.0 kJ mol(-1) H2O for hydrated zeolite Na-A and 20.5 kJ mol(-1) H2O for hydrated zeolite 97.9% CaNa-A. Enthalpies of formation of Ca-exchanged zeolites A are less exothermic than for zeolite Na-A. A linear relationship between the formation enthalpy and the extent of calcium substitution was observed. The energetic effect of Ca-exchange on zeolite A is discussed with an emphasis on the complex interactions between the zeolite framework, cations, and water.

High-precision measurement of phenylalanine δ15N values for environmental samples: a new approach coupling high-pressure liquid chromatography purification and elemental analyzer isotope ratio mass spectrometry.

PubMed

Broek, Taylor A B; Walker, Brett D; Andreasen, Dyke H; McCarthy, Matthew D

2013-11-15

Compound-specific isotope analysis of individual amino acids (CSI-AA) is a powerful new tool for tracing nitrogen (N) source and transformation in biogeochemical cycles. Specifically, the δ(15)N value of phenylalanine (δ(15)N(Phe)) represents an increasingly used proxy for source δ(15)N signatures, with particular promise for paleoceanographic applications. However, current derivatization/gas chromatography methods require expensive and relatively uncommon instrumentation, and have relatively low precision, making many potential applications impractical. A new offline approach has been developed for high-precision δ(15)N measurements of amino acids (δ(15)N(AA)), optimized for δ(15)N(Phe) values. Amino acids (AAs) are first purified via high-pressure liquid chromatography (HPLC), using a mixed-phase column and automated fraction collection. The δ(15)N values are determined via offline elemental analyzer-isotope ratio mass spectrometry (EA-IRMS). The combined HPLC/EA-IRMS method separated most protein AAs with sufficient resolution to obtain accurate δ(15)N values, despite significant intra-peak isotopic fractionation. For δ(15)N(Phe) values, the precision was ±0.16‰ for standards, 4× better than gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS; ±0.64‰). We also compared a δ(15)N(Phe) paleo-record from a deep-sea bamboo coral from Monterey Bay, CA, USA, using our method versus GC/C/IRMS. The two methods produced equivalent δ(15)N(Phe) values within error; however, the δ(15)N(Phe) values from HPLC/EA-IRMS had approximately twice the precision of GC/C/IRMS (average stdev of 0.27‰ ± 0.14‰ vs 0.60‰ ± 0.20‰, respectively). These results demonstrate that offline HPLC represents a viable alternative to traditional GC/C/IMRS for δ(15)N(AA) measurement. HPLC/EA-IRMS is more precise and widely available, and therefore useful in applications requiring increased precision for data interpretation (e.g. δ(15)N paleoproxies). Copyright © 2013 John Wiley & Sons, Ltd.

Theme-Based Bidisciplinary Chemistry Laboratory Modules

NASA Astrophysics Data System (ADS)

Leber, Phyllis A.; Szczerbicki, Sandra K.

1996-12-01

A thematic approach to each of the two introductory chemistry laboratory sequences, general and organic chemistry, not only provides an element of cohesion but also stresses the role that chemistry plays as the "central science" and emphasizes the intimate link between chemistry and other science disciplines. Thus, in general chemistry the rubric "Environmental Chemistry" affords connections to the geosciences, whereas experiments on the topic of "Plant Assays" bridge organic chemistry and biology. By establishing links with other science departments, the theme-based laboratory experiments will satisfy the following multidisciplinary criteria: (i) to demonstrate the general applicability of core methodologies to the sciences, (ii) to help students relate concepts to a broader multidisciplinary context, (iii) to foster an attitude of both independence and cooperation that can transcend the teaching laboratory to the research arena, and (iv) to promote greater cooperation and interaction between the science departments. Fundamentally, this approach has the potential to impact the chemistry curriculum significantly by including student decision-making in the experimental process. Furthermore, the incorporation of GC-MS, a powerful tool for separation and identification as well as a state-of-the-art analytical technique, in the modules will enhance the introductory general and organic chemistry laboratory sequences by making them more instrument-intensive and by providing a reliable and reproducible means of obtaining quantitative analyses. Each multifaceted module has been designed to meet the following criteria: (i) a synthetic protocol including full spectral characterization of products, (ii) quantitative and statistical analyses of data, and (iii) construction of a database of results. The database will provide several concrete functions. It will foster the idea that science is a continuous incremental process building on the results of earlier experimentalists, it will reinforce an understanding of the scientific method by allowing students to propose testable hypotheses based on previous work, and it will generate a large body of quantitative data that can be used to illustrate the fundamentals of data analysis, including statistical measures of uncertainty. We have already developed several "Environmental Chemistry" modules for general chemistry, including monitoring for orthophosphate and nitrate concentrations in water using colorimetric analyses and assaying for gasoline contamination in water and soil samples using GC-MS. Another module dealing with herbicide residues in soil is still being explored. However, we purposefully choose here to emphasize the two modules that are under development for implementation in the organic chemistry laboratory sequence. The first "Plant Assay" project focuses on fatty acid methyl esters (FAMEs) and involves three discrete phases: (i) synthesis and characterization of FAME standards, (ii) isolation of the fatty acids (as FAMEs) from a variety of different plant leaves that will be collected by BIO 110 students on field trips, and (iii) qualitative and quantitative analysis of the plant leaf extract for whole-leaf lipid composition. Acid-catalyzed Fischer esterification of carboxylic acids in methanol is a standard methodology for the preparation of methyl esters. A textbook procedure (1) for the synthesis of ethyl laurate has been employed, with good success, to prepare eight FAMEs in yields of ca. 70%. Conversion of leaf phospholipids to FAMEs proceeds readily via a transesterification reaction. Treatment of the whole leaf in a methanolic HCl solution for an hour at 80 °C (2) is sufficient after extraction in hexane to provide a suitable sample for GC-MS analysis. Preliminary results obtained with an HP GCD system indicate that GC-MS will afford highly reliable quantitative data on FAME lipid composition. Possible extensions of the project include using boron trifluoride in methanol to effect transesterification (3) and examining the effect of variations in leaf type and season on lipid composition. A second "Plant Assay" study involves preparing and characterizing analogs of naphthalene-1-acetamide, which is the active growth-promoting ingredient in commercial preparations such as Transplantone® and Rootone®. There are two direct methods for synthesizing the amide from the native plant growth regulator ("auxin") or carboxylic acid: acid-catalyzed hydrolysis of the nitrile or ammonolysis of the acid chloride derivative, prepared in situ from the acid by treatment with thionyl chloride (4). In the spring of 1996, organic chemistry students synthesized the amide derivatives of a number of auxins via the acid chloride intermediate, which is more efficiently prepared using oxalyl chloride (40-60% overall yield) instead of thionyl chloride (20-40% overall yield), or via nitrile hydrolysis (72-99% yield). Plant bioassays, based on measurement of pea stem segment elongation (5) have only been performed on the acetamide derivatives of three auxins, indole-3-acetic acid (IAA), naphthalene-1-acetic acid (1-NAA), and naphthalene-2-acetic acid (2-NAA). In comparison with the control, indole-3-acetamide and naphthalene-1-acetamide promoted growth by 50% and 90%, respectively. The acetamide of 2-NAA impeded growth by 30% relative to the control, an observation consistent with the known antiauxin activity of 2-NAA (6). Acquisition of the necessary imaging system for the teaching laboratory will enable students to extend these quantitative studies to other auxin conjugates. Acknowledgment We are grateful to the NSF for financial support through the Division of Undergraduate Education (DUE-9455693 and DUE-9550890). Literature Cited 1. Mayo, D. W.; Pike, R. M.; Trumper, P. K. Microscale Organic Laboratory, 3rd ed; John Wiley & Sons: New York, 1994; pp 202-203. 2. Browse, J.; McCourt, P. J.; Somerville, C. R. Anal. Biochem. 1986, 152, 141. 3. Rodig, O. R.; Bell, C. E., Jr.; Clark, A. K. Organic Chemistry Laboratory; Saunders: Philadelphia, 1990; p 455. 4. Reference 3, pp 361-365. 5. Ballal, S.; Ellias, R.; Fluck, R.; Jameton, R.; Leber, P.; Lirio, R.; Salama, D. Plant Physiol. Biochem. 1993, 31, 249-255. 6. Venis, M. A.; Napier, R. M. Plant Growth Regulation 1991, 10, 329-340.

In Vitro Propagation of Sambong (Blumea balsamifera Linn.).

PubMed

Soriano, Thelma L; Cangao, Evangelina C

2016-01-01

Terminal shoot tips of sambong (Blumea balsamifera Linn.) are cultured to initiate and regenerate shoots on Murashige and Skoog (MS) medium containing 1.0 mg/L benzyl adenine (BA). After 1 month, shoots, usually 4.5 cm long are separated and subcultured for multiplication. Regenerated shoots, about 6 cm long are rooted on MS medium supplemented with 1.0 mg/L naphthalene acetic acid (NAA). Exposure of shoots to high humidity for the first 2 weeks and equal proportion (1:1:1) of sterile sand, compost, and coir dust as potting mix favors the development of whole sambong plants. Young shoots from in vitro-derived sambong plants could also be used for propagation.

Investigation of Fe and Ca in non-stimulated human saliva using NAA

NASA Astrophysics Data System (ADS)

de Medeiros, J. A. G.; Zamboni, C. B.; Kovacs, L.; Lewgoy, H. R.

2015-07-01

In this study we investigated non-stimulated human whole saliva of healthy subjects and patients with periodontal disease using Neutron Activation Analysis technique (NAA). The measurements were performed in the IEA-R1 nuclear reactor at IPEN-CNEN/SP. We found considerable metabolic changes mainly in Fe and Ca concentration in whole saliva of periodontal patients. These data are useful for identifying or preventing this oral disease in the Brazilian population.

Green Cloud on the Horizon

NASA Astrophysics Data System (ADS)

Ali, Mufajjul

This paper proposes a Green Cloud model for mobile Cloud computing. The proposed model leverage on the current trend of IaaS (Infrastructure as a Service), PaaS (Platform as a Service) and SaaS (Software as a Service), and look at new paradigm called "Network as a Service" (NaaS). The Green Cloud model proposes various Telco's revenue generating streams and services with the CaaS (Cloud as a Service) for the near future.

In vitro micropropagation in Polygonatum verticillatum (L.) All. an important threatened medicinal herb of Northern India.

PubMed

Bisht, Shivani; Bisht, N S; Bhandari, Snehlata

2012-01-01

An ideal micropropagation method of Polygonatum verticillatum has been developed using stem disc explants. Multiple shoots were initiated from stem disc explants on Murashige and Skoog (MS) medium fortified with different concentrations (0.25-10.0 mgl(-1)) and combinations of cytokinins (BAP, Kn and TDZ) along with (0.5-1.0 mgl(-1)) auxins (NAA/IBA/IAA). 1.0 mgl(-1) BAP with 0.5 mgl(-1) NAA was found to be the most effective in producing maximum number of shoots. Regular subculturing of these in vitro multiple shoots induced profuse growth of lateral roots in the same medium. Individual shoots were excised and rooted in vitro on half strength MS medium with 1.0 mgl(-1) NAA. Regenerants were hardened in growth chamber with high humidity and showed a high rate of survival.

Micropropagation of Origanum acutidens (HAND.-MAZZ.) IETSWAART using stem node explants.

PubMed

Yildirim, Mehmet Ugur

2013-01-01

Origanum acutidens (HAND.-MAZZ.) IETSWAART is a promising ornamental plant that can be widely used in landscape management. It is endemic to Eastern Anatolian region of Turkey. Tissue culture has not been used to micropropagate it. The study reports stem node explants from one-week-old seedlings of the plant for successful micropropagation. The stem nodes were cultured on MS medium containing 0.6, 1.2, 1.8, and 2.4 mg/L BAP with 0.2 mg/L NAA. Visible effects of culture media on shoot proliferation were recorded. Shoot regeneration rate was maximum on MS medium containing 1.80 mg/L BAP-0.2 mg/L NAA. The micropropagated shoots were rooted on MS medium containing 0.2 mg/L NAA. All microrooted plantlets survived during acclimatisation on peat moss. It was concluded that O. acutidens can be successfully micropropagated under in vitro conditions.

Micropropagation of Origanum acutidens (HAND.-MAZZ.) IETSWAART Using Stem Node Explants

PubMed Central

Yildirim, Mehmet Ugur

2013-01-01

Origanum acutidens (HAND.-MAZZ.) IETSWAART is a promising ornamental plant that can be widely used in landscape management. It is endemic to Eastern Anatolian region of Turkey. Tissue culture has not been used to micropropagate it. The study reports stem node explants from one-week-old seedlings of the plant for successful micropropagation. The stem nodes were cultured on MS medium containing 0.6, 1.2, 1.8, and 2.4 mg/L BAP with 0.2 mg/L NAA. Visible effects of culture media on shoot proliferation were recorded. Shoot regeneration rate was maximum on MS medium containing 1.80 mg/L BAP-0.2 mg/L NAA. The micropropagated shoots were rooted on MS medium containing 0.2 mg/L NAA. All microrooted plantlets survived during acclimatisation on peat moss. It was concluded that O. acutidens can be successfully micropropagated under in vitro conditions. PMID:23983625

The Northern Appalachian Anomaly: A modern asthenospheric upwelling

NASA Astrophysics Data System (ADS)

Menke, William; Skryzalin, Peter; Levin, Vadim; Harper, Thomas; Darbyshire, Fiona; Dong, Ted

2016-10-01

The Northern Appalachian Anomaly (NAA) is an intense, laterally localized (400 km diameter) low-velocity anomaly centered in the asthenosphere beneath southern New England. Its maximum shear velocity contrast, at 200 km depth, is about 10%, and its compressional-to-shear velocity perturbation ratio is about unity, values compatible with it being a modern thermal anomaly. Although centered close to the track of the Great Meteor hot spot, it is not elongated parallel to it and does not crosscut the cratonic margin. In contrast to previous explanations, we argue that the NAA's spatial association with the hot spot track is coincidental and that it is caused by small-scale upwelling associated with an eddy in the asthenospheric flow field at the continental margin. That the NAA is just one of several low-velocity features along the eastern margin of North America suggests that this process may be globally ubiquitous.

Automatic sample changer control software for automation of neutron activation analysis process in Malaysian Nuclear Agency

NASA Astrophysics Data System (ADS)

Yussup, N.; Ibrahim, M. M.; Rahman, N. A. A.; Mokhtar, M.; Salim, N. A. A.; Soh@Shaari, S. C.; Azman, A.; Lombigit, L.; Azman, A.; Omar, S. A.

2018-01-01

Most of the procedures in neutron activation analysis (NAA) process that has been established in Malaysian Nuclear Agency (Nuclear Malaysia) since 1980s were performed manually. These manual procedures carried out by the NAA laboratory personnel are time consuming and inefficient especially for sample counting and measurement process. The sample needs to be changed and the measurement software needs to be setup for every one hour counting time. Both of these procedures are performed manually for every sample. Hence, an automatic sample changer system (ASC) that consists of hardware and software is developed to automate sample counting process for up to 30 samples consecutively. This paper describes the ASC control software for NAA process which is designed and developed to control the ASC hardware and call GammaVision software for sample measurement. The software is developed by using National Instrument LabVIEW development package.

Effects of IAA, IBA, NAA, and GA3 on rooting and morphological features of Melissa officinalis L. stem cuttings.

PubMed

Sevik, Hakan; Guney, Kerim

2013-01-01

This study analyzed the potential of producing Melissa officinalis L. using stem cuttings. Four different hormones (IAA, IBA, NAA, and GA3) were applied to the cuttings, with and without buds, in two doses (1000 mg/L and 5000 mg/L), and after 60 days, 10 morphological characteristics of newly generated plants were detected, and a statistical analysis was carried out. The results of the study show that the cuttings with at least one bud must be used in order to produce M. officinalis using stem cuttings. Even though the auxin group hormones (IAA, IBA, and NAA) do not have an apparent effect on rooting percentage, these hormones were detected to affect the morphological characteristics of the newly generated plants, especially root generation. GA3 application has a considerable effect on stem height.

3D Nanoporous Anodic Alumina Structures for Sustained Drug Release

PubMed Central

Xifré-Pérez, Elisabet; Eckstein, Chris; Ferré-Borrull, Josep

2017-01-01

The use of nanoporous anodic alumina (NAA) for the development of drug delivery systems has gained much attention in recent years. The release of drugs loaded inside NAA pores is complex and depends on the morphology of the pores. In this study, NAA, with different three-dimensional (3D) pore structures (cylindrical pores with several pore diameters, multilayered nanofunnels, and multilayered inverted funnels) were fabricated, and their respective drug delivery rates were studied and modeled using doxorubicin as a model drug. The obtained results reveal optimal modeling of all 3D pore structures, differentiating two drug release stages. Thus, an initial short-term and a sustained long-term release were successfully modeled by the Higuchi and the Korsmeyer–Peppas equations, respectively. This study demonstrates the influence of pore geometries on drug release rates, and further presents a sustained long-term drug release that exceeds 60 days without an undesired initial burst. PMID:28825654

Quantification of GABA, glutamate and glutamine in a single measurement at 3 T using GABA‐edited MEGA‐PRESS

PubMed Central

Sanaei Nezhad, Faezeh; Anton, Adriana; Michou, Emilia; Jung, JeYoung; Parkes, Laura M.

2017-01-01

γ‐Aminobutyric acid (GABA) and glutamate (Glu), major neurotransmitters in the brain, are recycled through glutamine (Gln). All three metabolites can be measured by magnetic resonance spectroscopy in vivo, although GABA measurement at 3 T requires an extra editing acquisition, such as Mescher–Garwood point‐resolved spectroscopy (MEGA‐PRESS). In a GABA‐edited MEGA‐PRESS spectrum, Glu and Gln co‐edit with GABA, providing the possibility to measure all three in one acquisition. In this study, we investigated the reliability of the composite Glu + Gln (Glx) peak estimation and the possibility of Glu and Gln separation in GABA‐edited MEGA‐PRESS spectra. The data acquired in vivo were used to develop a quality assessment framework which identified MEGA‐PRESS spectra in which Glu and Gln could be estimated reliably. Phantoms containing Glu, Gln, GABA and N‐acetylaspartate (NAA) at different concentrations were scanned using GABA‐edited MEGA‐PRESS at 3 T. Fifty‐six sets of spectra in five brain regions were acquired from 36 healthy volunteers. Based on the Glu/Gln ratio, data were classified as either within or outside the physiological range. A peak‐by‐peak quality assessment was performed on all data to investigate whether quality metrics can discriminate between these two classes of spectra. The quality metrics were as follows: the GABA signal‐to‐noise ratio, the NAA linewidth and the Glx Cramer–Rao lower bound (CRLB). The Glu and Gln concentrations were estimated with precision across all phantoms with a linear relationship between the measured and true concentrations: R 1 = 0.95 for Glu and R 1 = 0.91 for Gln. A quality assessment framework was set based on the criteria necessary for a good GABA‐edited MEGA‐PRESS spectrum. Simultaneous criteria of NAA linewidth <8 Hz and Glx CRLB <16% were defined as optimum features for reliable Glu and Gln quantification. Glu and Gln can be reliably quantified from GABA‐edited MEGA‐PRESS acquisitions. However, this reliability should be controlled using the quality assessment methods suggested in this work. PMID:29130590

Evidence for Metabolic Hypothalamo-Amygdala Dysfunction in Narcolepsy

PubMed Central

Poryazova, Rositsa; Schnepf, Betina; Werth, Esther; Khatami, Ramin; Dydak, Ulrike; Meier, Dieter; Boesiger, Peter; Bassetti, Claudio L.

2009-01-01

Study Objectives: Proton resonance spectroscopy (1H-MRS) allows noninvasive chemical tissue analysis in the living brain. As neuronal loss and gliosis have been described in narcolepsy, metabolites of primary interest are N-acetylaspartate (NAA), a marker of neuronal integrity and myo-Inositol (mI), a glial marker and second messenger involved in the regulation of intracellular calcium. One 1H-MRS study in narcolepsy found no metabolic changes in the pontomedullary junction. Another study showed a reduction in NAA/creatine-phosphocreatine (Cr) in the hypothalamus of narcolepsy patients with cataplexy. We aimed to test for metabolic changes in specific brain areas, “regions of interest,” thought to be involved in emotional processing, sleep regulation and pathophysiology of narcolepsy: hypothalamus, pontomesencephalic junction and both amygdalae. Design: We performed 1H-MRS using a 3T Philips Achieva whole body MR scanner. Single-voxel proton MR spectra were acquired and quantified with LCModel to determine metabolite concentration ratios. Setting: The participants in the study were recruited at the outpatient clinic for sleep medicine, Department of Neurology and magnetic resonance spectroscopy was performed at the MRI facility, University Hospital Zurich. Participants: 1H-MRS was performed in fourteen narcolepsy patients with cataplexy, CSF hypocretin deficiency (10/10) and HLA-DQB1*0602 positivity (14/14) and 14 age, gender and body mass index matched controls. Patients were treatment naïve or off therapy for at least 14 days before scanning. Measurements and Results: No differences were observed in the regions of interest for (total NAA)/Cr ratios. Myo-Inositol (mI)/Cr was significantly lower in the right amygdala of the patients, compared to controls (P < 0.042). Significant negative correlations only in the patients group were found between (total NAA)/Cr in hypothalamus and mI/Cr in the right amygdala (r = −0.89, P < 0.001), between mI/Cr in hypothalamus and (total NAA)/Cr in the right amygdala (r = −63, P < 0.05) and between mI/Cr in the left amygdala and total NAA)/Cr in the pontomesencephalic junction (r = −0.69, P < 0.05). Conclusion: Our findings suggest amygdala involvement and possible hypothalamo-amygdala dysfunction in narcolepsy. Citation: Poryazova R; Werth E; Khatami R; Dydak U; Meier D; Boesiger P; Bassetti CL. Evidence for metabolic hypothalamo-amygdala dysfunction in narcolepsy. SLEEP 2009;32(5):607-613. PMID:19480227

Local Upper Mantle Upwelling beneath New England: Evidence from Seismic Anisotropy.

NASA Astrophysics Data System (ADS)

Levin, V. L.; Long, M. D.; Lopez, I.; Li, Y.; Skryzalin, P. A.

2017-12-01

The upper mantle beneath eastern North America contains regions where seismic wave speed is significantly reduced. As they cut across the trend of the Appalachian terranes, these anomalies likely post-date the Paleozoic assembly of Pangea. Most prominent of them, the North Appalachian Anomaly (NAA), has been alternatively explained by the localized disruption of lithospheric fabric, the passage of the Great Meteor Hot Spot, and the current local upwelling of the asthenosphere. Comprehensive mapping of shear wave splitting identified a local perturbation of an otherwise uniform regional pattern, with no apparent splitting occurring at a site within the NAA. To evaluate the reality of this apparent localized disruption in the anisotropic fabric of the upper mantle beneath northeastern North America we used observations of shear wave splitting from a set of long-running observatories not included in previous studies. Three methods of evaluating shear wave splitting (rotation-correlation, minimization of the transverse component, and the splitting intensity) yield complementary results. We show that splitting of core-refracted shear waves within the outline of the NAA is significantly weaker than towards its edges and beyond them (Figure 1). Average fast orientations are close to the absolute plate motion in the hot-spot reference frame, thus we can attribute a large fraction of this signal to the coherently sheared sub-lithospheric upper mantle. A decrease in average delay we observe, from 1 s outside the NAA to under 0.2 s within it, translates into a reduction of the vertical extent of the sheared layer from 130 km to 16 km (assuming 4% anisotropy), or alternatively into a weakening of the azimuthal anisotropy from 5% to 0.6% (assuming a 100 km thick layer). The splitting reduction within the NAA is consistent with a localized change in anisotropic fabric that would be expected in case of geologically recent sub-vertical flow overprinting the broadly uniform upper mantle fabric detected throughout the region. Figure 1. Splitting intensity (red circles) plotted over best-fitting sinusoidal functions (blue, parameters in upper right) and predictions based on average delays and fast polarizations (green, parameters in upper left). Outlines of the NAA at 200 km depth from tomographic studies using Earthscope data.

Automation system for neutron activation analysis at the reactor IBR-2, Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia.

PubMed

Pavlov, Sergey S; Dmitriev, Andrey Yu; Frontasyeva, Marina V

The present status of development of software packages and equipment designed for automation of NAA at the reactor IBR-2 of FLNP, JINR, Dubna, RF, is described. The NAA database, construction of sample changers and software for automation of spectra measurement and calculation of concentrations are presented. Automation of QC procedures is integrated in the software developed. Details of the design are shown.

The biology and in vitro propagation of the ornamental aquatic plant, Aponogeton ulvaceus.

PubMed

Kam, Melissa Yit Yee; Chai, Li Chin; Chin, Chiew Foan

2016-01-01

Aponogeton ulvaceus Baker (Aponogetonaceae) is a commercially important ornamental aquatic plant species with traditional medicinal uses. Due to the low survival rate of seedlings, propagation by conventional means has been met with many difficulties. In this study, botanical aspects of A. ulvaceus were examined with regards to the morphology, anatomy and physiology of the plant and an efficient protocol for its in vitro propagation using immature tuber explants has been established. The existence of glandular trichomes on the leaves was discovered and the occurrence of circumnutation in A. ulvaceus has been demonstrated. Immature tuber segments with meristems were cultured on MS medium supplemented with various combinations (0, 1, 2, and 3 mg/L) of BAP and NAA for callus induction. The highest percentage of callus production (100 %) was obtained in two different treatments: 1 mg/L BAP and 3 mg/L NAA, and 2 mg/L BAP and 3 mg/L NAA. For shoot and root organogenesis, the combination of 1 mg/L BAP and 1 mg/L NAA was shown to be significant for A. ulvaceus regeneration when compared to control, which yields a mean shoot and root number of 22.50 and 29.50 respectively. The current protocol is the first reported successful establishment of in vitro clonal propagation of A. ulvaceus .

Brain metabolites in autonomic regulatory insular sites in heart failure.

PubMed

Woo, Mary A; Yadav, Santosh K; Macey, Paul M; Fonarow, Gregg C; Harper, Ronald M; Kumar, Rajesh

2014-11-15

Autonomic, pain, and neuropsychologic comorbidities appear in heart failure (HF), likely resulting from brain changes, indicated as loss of structural integrity and functional deficits. Among affected brain sites, the anterior insulae are prominent in serving major regulatory roles in many of the disrupted functions commonly seen in HF. Metabolite levels, including N-acetylaspartate (NAA), creatine (Cr), choline (Cho), and myo-inositol (MI), could indicate the nature of anterior insula tissue injury in HF. The study aim was to assess anterior insular metabolites to determine processes mediating autonomic, pain, and neuropsychologic disruptions in HF. We performed magnetic resonance spectroscopy in bilateral anterior insulae in 11 HF and 53 controls, using a 3.0-Tesla magnetic resonance imaging scanner. Peaks for NAA at 2.02 ppm, Cr at 3.02 ppm, Cho at 3.2 ppm, and MI at 3.56 ppm were assigned, peak areas were calculated, and metabolites were expressed as ratios, including NAA/Cr, Cho/Cr, and MI/Cr. HF patients showed significantly increased Cho/Cr ratios, indicative of glial proliferation or injury, on the left anterior insula, and reduced NAA/Cr levels, suggesting neuronal loss/dysfunction, on the right anterior insula over controls. No differences in MI/Cr ratios appeared between groups. Right anterior insular neuronal loss and left glial alterations may contribute to distorted autonomic, pain, and neuropsychologic functions found in HF. Copyright © 2014 Elsevier B.V. All rights reserved.

Changes in NAA and lactate following ischemic stroke: a serial MR spectroscopic imaging study.

PubMed

Muñoz Maniega, S; Cvoro, V; Chappell, F M; Armitage, P A; Marshall, I; Bastin, M E; Wardlaw, J M

2008-12-09

Although much tissue damage may occur within the first few hours of ischemic stroke, the duration of tissue injury is not well defined. We assessed the temporal pattern of neuronal loss and ischemia after ischemic stroke using magnetic resonance spectroscopic imaging (MRSI) and diffusion-weighted imaging (DWI). We measured N-acetylaspartate (NAA) and lactate in 51 patients with acute ischemic stroke at five time points, from admission to 3 months, in voxels classified as normal, possibly or definitely abnormal (ischemic) according to the appearance of the stroke lesion on the admission DWI. We compared changes in NAA and lactate in different voxel classes using linear mixed models. NAA was significantly reduced from admission in definitely and possibly abnormal (p < 0.01) compared to contralateral normal voxels, reaching a nadir by 2 weeks and remaining reduced at 3 months. Lactate was significantly increased in definitely and possibly abnormal voxels (p < 0.01) during the first 5 days, falling to normal at 2 weeks, rising again later in these voxels. The progressive fall in N-acetylaspartate suggests that some additional neuronal death may continue beyond the first few hours for up to 2 weeks or longer. The mechanism is unclear but, if correct, then it is possible that interventions to limit this ongoing subacute tissue damage might add to the benefit of hyperacute treatment, making further improvements in outcome possible.

Sunrise effects on VLF signals propagating over a long north-south path

NASA Astrophysics Data System (ADS)

Clilverd, Mark A.; Thomson, Neil R.; Rodger, Craig J.

1999-07-01

We present a detailed study of the times of amplitude minima observed on the 12-Mm path from NAA (24 kHz, 1 MW, Cutler, Maine) to Faraday, Antarctica, during the period 1990-1995. (NAA is a naval transmitter call sign.) This study represents the first account of the effect of the sunrise terminator when it is parallel to a propagation path at some times of the year. Since the NAA-Faraday path is within 3° of the north-south meridian, parallel orientation happens close to the equinoxes, while the maximum angle of incidence occurs during the solstices. During the solstices the terminator takes a significant length of time to cross the entire propagation path, so modal conversion effects are observed over a range of hours. During the equinoxes, however, the leading edge of the night-day transition region crosses the whole propagation path within 20 min. The interpretation of the timing of minima is consistent with modal conversion taking place as the sunrise terminator crosses the NAA-Faraday transmission path at specific, consistent locations. The timing of minima is remarkably consistent from year to year. Long wave propagation modeling is used to show that the location of nightside minima at an altitude of 45-75 km in the subionospheric waveguide represents the location of the sunrise terminator on the great circle path when dayside minima occur.

US EPA Nonattainment Areas and Designations-Lead (2008 NAAQS)

EPA Pesticide Factsheets

This web service contains the following layers: Lead NAA 2008 NAAQS and Lead NAA Centroids 2008 NAAQS. Full FGDC metadata records for each layer may be found by clicking the layer name at the web service endpoint (https://gispub.epa.gov/arcgis/rest/services/OAR_OAQPS/NAA2008Lead/MapServer) and viewing the layer description. These layers identify areas in the U.S. where air pollution levels have not met the National Ambient Air Quality Standards (NAAQS) for criteria air pollutants and have been designated nonattainment?? areas (NAA). The data are updated weekly from an OAQPS internal database. However, that does not necessarily mean the data have changed. The EPA Office of Air Quality Planning and Standards (OAQPS) has set National Ambient Air Quality Standards for six principal pollutants, which are called criteria pollutants. Under provisions of the Clean Air Act, which is intended to improve the quality of the air we breathe, EPA is required to set National Ambient Air Quality Standards for six common air pollutants. These commonly found air pollutants (also known as criteria pollutants) are found all over the United States. They are particle pollution (often referred to as particulate matter), ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. For each criteria pollutant, there are specific procedures used for measuring ambient concentrations and for calculating long-term (quarterly or annual) and/or short-term (24-hour) exposure l

US EPA Nonattainment Areas and Designations-8 Hour Ozone (2008 NAAQS)

EPA Pesticide Factsheets

This web service contains the following layers: Ozone 2008 NAAQS NAA State Level and Ozone 2008 NAAQS NAA National Level. Full FGDC metadata records for each layer may be found by clicking the layer name at the web service endpoint (https://gispub.epa.gov/arcgis/rest/services/OAR_OAQPS/NAA2008Ozone8hour/MapServer) and viewing the layer description. These layers identify areas in the U.S. where air pollution levels have not met the National Ambient Air Quality Standards (NAAQS) for criteria air pollutants and have been designated nonattainment?? areas (NAA). The data are updated weekly from an OAQPS internal database. However, that does not necessarily mean the data have changed. The EPA Office of Air Quality Planning and Standards (OAQPS) has set National Ambient Air Quality Standards for six principal pollutants, which are called criteria pollutants. Under provisions of the Clean Air Act, which is intended to improve the quality of the air we breathe, EPA is required to set National Ambient Air Quality Standards for six common air pollutants. These commonly found air pollutants (also known as criteria pollutants) are found all over the United States. They are particle pollution (often referred to as particulate matter), ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. For each criteria pollutant, there are specific procedures used for measuring ambient concentrations and for calculating long-term (quarterly or annual) and/or short-

US EPA Nonattainment Areas and Designations-8 Hour Ozone (1997 NAAQS)

EPA Pesticide Factsheets

This web service contains the following layers: Ozone 1997 NAAQS NAA State Level and Ozone 1997 NAAQS NAA National Level. Full FGDC metadata records for each layer may be found by clicking the layer name at the web service endpoint (https://gispub.epa.gov/arcgis/rest/services/OAR_OAQPS/NAA1997Ozone8hour/MapServer) and viewing the layer description. These layers identify areas in the U.S. where air pollution levels have not met the National Ambient Air Quality Standards (NAAQS) for criteria air pollutants and have been designated nonattainment?? areas (NAA). The data are updated weekly from an OAQPS internal database. However, that does not necessarily mean the data have changed. The EPA Office of Air Quality Planning and Standards (OAQPS) has set National Ambient Air Quality Standards for six principal pollutants, which are called criteria pollutants. Under provisions of the Clean Air Act, which is intended to improve the quality of the air we breathe, EPA is required to set National Ambient Air Quality Standards for six common air pollutants. These commonly found air pollutants (also known as criteria pollutants) are found all over the United States. They are particle pollution (often referred to as particulate matter), ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. For each criteria pollutant, there are specific procedures used for measuring ambient concentrations and for calculating long-term (quarterly or annual) and/or short

[Clinical application of proton magnetic resonance spectroscopy in children with idiopathic epilepsy].

PubMed

Shao, Xiao-Li; Zhou, Zhong-Shu; Hong, Wen

2010-06-01

This study examined the biochemical metabolism by proton magnetic resonance spectroscopy ('H-MRS) in order to explore the value of 'H-MRS in idiopathic epilepsy in children. Thirty-three children with idiopathic epilepsy (14 cases with history of febrile seizures and 19 cases without) and six normal controls experienced MRI of the skull and brain and single-voxel 'H-MRS examinations of the hippocampi-temporal lobe. The signal intensities of N-acetylaspartate (NAA), eatine+phosphocreatine (Cr), choline-containing compounds (Cho) and lactate (Lac) and the ratios of NAA/ (Cho+Cr) and Lac/Cr were compared between the patients and normal controls. MRI examination showed that only one child with epilepsy had myelin dysplasia. 'H-MRS examination showed that the ratio of NAA/ (Cho+Cr) in the epilepsy group was lower than that in the control group (0.64+/-0.07 vs 0.73+/-0.05; P<0.01). The epileptic children with history of febrile seizures had a more decreased ratio of NAA/ (Cho+Cr) compared with those without the history (0.61+/-0.07 vs 0.66+/-0.06; P<0.05). There were no significant differences in the ratio of Lac/Cr between the epilepsy and the control groups. 'H-MRS may provide early information on brain injury sensitively and non-invasively in children with epilepsy. It may be used for diagnosis and prognosis evaluation of epilepsy.

Brain Metabolites in Autonomic Regulatory Insular Sites in Heart Failure

PubMed Central

Woo, Mary A.; Yadav, Santosh K.; Macey, Paul M.; Fonarow, Gregg C.; Harper, Ronald M.; Kumar, Rajesh

2014-01-01

Autonomic, pain, and neuropsychologic comorbidities appear in heart failure (HF), likely resulting from brain changes, indicated as loss of structural integrity and functional deficits. Among affected brain sites, the anterior insulae are prominent in serving major regulatory roles in many of the disrupted functions commonly seen in HF. Metabolite levels, including N-acetylaspartate (NAA), creatine (Cr), choline (Cho), and myo-inositol (MI), could indicate the nature of anterior insula tissue injury in HF. The study aim was to assess anterior insular metabolites to determine processes mediating autonomic, pain, and neuropsychologic disruptions in HF. We performed magnetic resonance spectroscopy in bilateral anterior insulae in 11 HF and 53 controls, using a 3.0-Tesla magnetic resonance imaging scanner. Peaks for NAA at 2.02ppm, Cr at 3.02ppm, Cho at 3.2ppm, and MI at 3.56ppm were assigned, peak areas calculated, and metabolites expressed as ratios, including NAA/Cr, Cho/Cr, and MI/Cr. HF patients showed significantly increased Cho/Cr ratios, indicative of glial proliferation or injury, on the left anterior insula, and reduced NAA/Cr levels, suggesting neuronal loss/dysfunction, on the right anterior insula over controls. No differences in MI/Cr ratios appeared between groups. Right anterior insular neuronal loss and left glial alterations may contribute to distorted autonomic, pain, and neuropsychologic functions found in HF. PMID:25248953

The effects of exogenous hormones on rooting process and the activities of key enzymes of Malus hupehensis stem cuttings.

PubMed

Zhang, Wangxiang; Fan, Junjun; Tan, Qianqian; Zhao, Mingming; Zhou, Ting; Cao, Fuliang

2017-01-01

Malus hupehensis is an excellent Malus rootstock species, known for its strong adverse-resistance and apomixes. In the present study, stem cuttings of M. hupehensis were treated with three types of exogenous hormones, including indole acetic acid (IAA), naphthalene acetic acid (NAA), or green growth regulator (GGR). The effects and mechanisms of exogenous hormone treatment and antioxidant enzyme activity on adventitious root formation were investigated. The results showed that the apparent morphology of the adventitious root had four stages, including root pre-emergence stage (S0), early stage of root formation (S1), massive root formation stage (S2), and later stage of root formation (S3). The suitable concentrations of the three exogenous hormones, IAA, NAA and GGR, were 100 mg·L-1, 300 mg·L-1, and 300 mg·L-1, respectively. They shortened the rooting time by 25-47.4% and increased the rooting percentages of cuttings by 0.9-1.3 times, compared with that in the control. The dispersion in S0 stage was 3.6 times of that in the S1 stage after exogenous hormone application. The earlier the third critical point (P3) appeared, the shorter the rooting time and the greater the rooting percentage of the cuttings. During rhizogenesis, the activities of three antioxidant enzymes (POD, SOD, and PPO) showed an A-shaped trend. However, peak values of enzyme activity appeared at different points, which were 9 d before the P3, P3, and the fourth critical point (P4), respectively. Exogenous hormone treatment reduced the time to reach the peak value by 18 days, although the peak values of the enzymatic activities did not significantly changed. Our results suggested that exogenous hormone treatment mainly acted during the root pre-emergence stage, accelerated the synthesis of antioxidant enzymes, reduced the rooting time, and consequently promoted root formation. The three kinds of antioxidant enzymes acted on different stages of rooting.

(1)H-MRS in glutaric aciduria type 1: impact of biochemical phenotype and age on the cerebral accumulation of neurotoxic metabolites.

PubMed

Harting, Inga; Boy, Nikolas; Heringer, Jana; Seitz, Angelika; Bendszus, Martin; Pouwels, Petra J W; Kölker, Stefan

2015-09-01

In glutaric aciduria type 1 (GA1) the neurotoxic metabolites glutaric acid (GA) and 3-hydroxyglutaric acid (3-OH-GA) accumulate within the brain. Due to limited efflux across the blood-brain-barrier biochemical monitoring of intracerebrally accumulating toxic metabolites is as yet not possible. To investigate brain metabolic patterns in glutaric aciduria type 1 using (1)H magnetic resonance spectroscopy ((1)H-MRS) with focus on detecting the disease-related neurotoxic metabolites GA and 3-OH-GA. Short echo time (1)H-MRS was performed in 13 treated metabolically stable patients. Twenty-one white matter and 16 basal ganglia spectra from 12 patients (age range 7 months - 22 years) were included. Subgroups based on age, biochemical phenotype and/or associated MRI changes were compared with control spectra. GA was elevated in white matter of patients. 3-OH-GA was elevated in white matter of older patients with associated signal changes on MRI, which was structurally characterized by decreased creatine and phosphocreatine (tCr) and elevated choline (Cho). Metabolite changes differed with biochemical phenotype and disease duration: Low excretors with up to 30% residual enzyme activity had only mildly, non-significantly elevated GA and mildly subnormal N-acetylaspartate (tNAA). High excretors with complete lack of enzyme activity had significantly increased GA, tNAA was mildly subnormal in younger and decreased in older high excretors. GA and 3-OH-GA are detectable by in vivo (1)H-MRS, which might finally allow biochemical follow-up monitoring of intracerebrally accumulating neurotoxic metabolites in GA1. A high excreting phenotype appears to be a risk factor for cerebral GA accumulation and progressive neuroaxonal compromise despite a similar clinical course in younger high and low excreting patients. This might have consequences for long-term outcome.

(1)H-magnetic resonance spectroscopy ((1)H-MRS) in methamphetamine dependence and methamphetamine induced psychosis.

PubMed

Howells, Fleur M; Uhlmann, Anne; Temmingh, Henk; Sinclair, Heidi; Meintjes, Ernesta; Wilson, Don; Stein, Dan J

2014-03-01

Methamphetamine (MA) use has been shown to decrease n-acetyl-aspartate (NAA), a marker of neuronal integrity and viability, on (1)H magnetic resonance spectroscopy ((1)H-MRS). However, little work has compared (1)H-MRS in MA dependent individuals and MA dependent individuals with MA induced psychotic disorder (MAP). Twenty six participants with MA dependence (sixteen without psychosis, ten with psychosis - MAP) and nineteen healthy controls underwent 2D-chemical shift imaging (1)H-MRS, which included voxels in the anterior cingulate cortices (ACC), dorsolateral prefrontal cortices (DLPFC), and frontal white matter. We compared metabolite concentrations relative to phosphocreatine+creatine (PCr+Cr) for n-acetyl-aspartate (NAA), n-acetyl-aspartate+n-acetyl-aspartyl-glutamate (NAA+NAAG), glutamate (Glu), glutamate+glutamine (Glu+Gln), myo-inositol, and glycerophosphocholine+phosphocholine (GPC+PCh) across groups. The MA groups showed significantly decreased relative NAA metabolite concentrations for right ACC and right DLPFC, compared with control group. The MA dependent group only showed significantly decreased choline metabolites for right DLPFC, compared with control group. The MAP group's relative NAA metabolite concentrations were significantly correlated with age of initial use and duration of MA use, these correlates were not apparent in MA dependent group. MA use is associated with decreased neuronal integrity and viability, specifically in the right ACC and right DLPFC. MA dependence showed active neurodegeneration in the right DLPFC, this was not apparent in the MAP group and may be related to the use of antipsychotic medication in the MAP group. The effects of MA use in MAP suggest that age of initial use presents a mismatch of neuronal plasticity, in frontal white vs. gray matter and duration of use relates to decreased neuronal integrity and viability. Further study is warranted from this initial study of (1)H-MRS in MAP, in particular longitudinal assessment of these individuals both neurobiologically ((1)H-MRS) and clinically - to determine disease progression. Copyright © 2014 Elsevier B.V. All rights reserved.

Optimization of Regeneration Conditions and In Vitro Propagation of Sideritis Stricta Boiss & Heldr.

PubMed

Yavuz, Dudu Özkum

2016-09-01

In this study the micropropagation of endemic species Sideritis stricta was investigated. Leaf segments and shoot explants (hypocotyl, single node and shoot tips) taken from in vitro growing plantlets and cultured on MS and B5 media containing different growth regulators combinations BAP (0.0, 1.0, 2.0 and 3.0mg/l) and NAA (0.0, 0.1 and 0.5mg/l). MS and B5 media supplemented with BAP (1.0, 2.0 and 3.0mg/l) and NAA (0.1mg/l) combinations or only BAP and kinetin (2.0 and 3.0mg/l) were used at the subculture experiments of shoots and MS and B5 media supplemented with different concentrations of IBA (0.0, 1.5, 3.0, 4.5 and 10.mg/l) were used at the rooting experiments. S. stricta seeds germinated at the rate of 100% when the seed coat was removed and endoperm with embryo part cultured on B5 medium. The single node explants taken from in vitro germinated and grown 30-40 days plantlets on B5 medium have been determined as the most successful explant at all used hormone combinations. B5 medium supplemented with 1.0mg/l BAP+0.1mg/l NAA and 2.0mg/l BAP+0.5mg/l NAA was determined as the most effective medium on shoot formation. At the first and second subculture, the highest shoot formation was maintained on medium supplemented with 1.0mg/l BAP+0.1mg/l NAA and the number of shoots per explant were 4 and 2.11, respectively. The highest multiplication rate has been determined as 33.76 at the end of second subculture. The best rooting was achieved on B5 medium supplemented with 4.5mg/l IBA. The rooted shoots were successfully acclimatized to outdoor conditions and survival rate was determined as 90%. Copyright © 2015 Elsevier B.V. All rights reserved.

Metabolite profiles in the anterior cingulate cortex of depressed patients differentiate those taking N-acetyl-cysteine versus placebo.

PubMed

Das, Pritha; Tanious, Michelle; Fritz, Kristina; Dodd, Seetal; Dean, Olivia M; Berk, Michael; Malhi, Gin S

2013-04-01

Increased oxidative stress is thought to contribute to the pathophysiology of major depressive disorder (MDD), which is in part due to diminished levels of glutathione, the primary anti-oxidant of the brain. Oral administration of N-acetyl-cysteine (NAC) replenishes glutathione and has therefore been shown to reduce depressive symptoms. Proton magnetic spectroscopy ((1)H-MRS) that allows quantification of brain metabolites pertinent to both MDD and oxidative biology may provide some novel insights into the neurobiological effects of NAC, and in particular metabolite concentrations within the anterior cingulate cortex (ACC) are likely to be important given the key role of this region in the regulation of affect. The aim of this study was to determine whether the metabolite profile of the ACC in MDD patients predicts treatment with adjunctive NAC versus placebo. This study was nested within a multicentre, randomized, double-blind, placebo-controlled study of MDD participants treated with adjunctive NAC. Participants (n = 76) from one site completed the spectroscopy component at the end of treatment (12 weeks). Spectra from a single-voxel in the ACC were acquired and absolute concentrations of glutamate (Glu), glutamate-glutamine (Glx), N-acetyl-aspartate (NAA) and myo-inositol (mI) were obtained. Binary logistic regression analysis was performed to determine whether metabolite profiles could predict NAC versus placebo group membership. When predicting group outcome (NAC or placebo), Glx, NAA and mI were a significant model, and had 75% accuracy, while controlling for depression severity and sex. However, the Glu, NAA and mI profile was only predictive at a trend level, with 68.3% accuracy. For both models, the log of the odds of a participant being in the NAC group was positively related to NAA, Glx and Glu levels and negatively related to mI levels. The finding of higher Glx and NAA levels being predictive of the NAC group provides preliminary support for the putative anti-oxidative role of NAC in MDD.

Impact of Methamphetamine on Regional Metabolism and Cerebral Blood Flow after Traumatic Brain Injury

PubMed Central

O'Phelan, Kristine; Ernst, Thomas; Park, Dalnam; Stenger, Andrew; Denny, Katherine; Green, Deborah; Chang, Cherylee; Chang, Linda

2014-01-01

Substance abuse is a frequent comorbid condition among patients with Traumatic Brain Injury (TBI), but little is known about its potential additive or interactive effects on tissue injury or recovery from TBI. This study aims to evaluate changes in regional metabolism and cerebral perfusion in subjects who used methamphetamine(METH) prior to sustaining a TBI. We hypothesized that METH use would decrease pericontusional cerebral perfusion and markers of neuronal metabolism, in TBI patients compared to those without METH use. Methods This is a single center prospective observational study. Adults with moderate and severe TBI were included. MRI scanning was performed on a 3 Tesla scanner. MP-RAGE and FLAIR sequences as well as Metabolite spectra of NAA and lactate in pericontusional and contralateral voxels identified on the MP-RAGE scans. A spiral-based FAIR sequence was used for the acquisition of cerebral blood flow (CBF) maps. Regional CBF images were analyzed using Image J open source software. Pericontusional and contralateral CBF, NAA and lactate were assessed in the entire cohort and in the METH and non-METH groups. Results 17 subjects completed the MR studies. Analysis of entire cohort: Pericontusional NAA concentrations (5.81 ± 2.0 mM/kg) were 12% lower compared to the contralateral NAA (6.98 ± 1.2 mM/kg; p=0.03). Lactate concentrations and CBF were not significantly different between the two regions, however, regional cerebral blood flow was equally reduced in the two regions. Subgroup analysis: 41% of subjects tested positive for METH. The mean age, Glasgow Coma Scale and time to scan did not differ between groups. The two subject groups also had similar regional NAA and lactate. Pericontusional CBF was 60% lower in the METH users than the non-users, p=0.04; contralateral CBF did not differ between the groups. Conclusion This small study demonstrates that tissue metabolism is regionally heterogeneous after TBI and pericontusional perfusion was significantly reduced in the METH subgroup. PMID:23836426

Brain Changes in Long-Term Zen Meditators Using Proton Magnetic Resonance Spectroscopy and Diffusion Tensor Imaging: A Controlled Study

PubMed Central

Fayed, Nicolás; Lopez del Hoyo, Yolanda; Andres, Eva; Serrano-Blanco, Antoni; Bellón, Juan; Aguilar, Keyla; Cebolla, Ausias; Garcia-Campayo, Javier

2013-01-01

Introduction This work aimed to determine whether 1H magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI) are correlated with years of meditation and psychological variables in long-term Zen meditators compared to healthy non-meditator controls. Materials and Methods Design. Controlled, cross-sectional study. Sample. Meditators were recruited from a Zen Buddhist monastery. The control group was recruited from hospital staff. Meditators were administered questionnaires on anxiety, depression, cognitive impairment and mindfulness. 1H-MRS (1.5 T) of the brain was carried out by exploring four areas: both thalami, both hippocampi, the posterior superior parietal lobule (PSPL) and posterior cingulate gyrus. Predefined areas of the brain were measured for diffusivity (ADC) and fractional anisotropy (FA) by MR-DTI. Results Myo-inositol (mI) was increased in the posterior cingulate gyrus and Glutamate (Glu), N-acetyl-aspartate (NAA) and N-acetyl-aspartate/Creatine (NAA/Cr) was reduced in the left thalamus in meditators. We found a significant positive correlation between mI in the posterior cingulate and years of meditation (r = 0.518; p = .019). We also found significant negative correlations between Glu (r = −0.452; p = .045), NAA (r = −0.617; p = .003) and NAA/Cr (r = −0.448; P = .047) in the left thalamus and years of meditation. Meditators showed a lower Apparent Diffusion Coefficient (ADC) in the left posterior parietal white matter than did controls, and the ADC was negatively correlated with years of meditation (r = −0.4850, p = .0066). Conclusions The results are consistent with the view that mI, Glu and NAA are the most important altered metabolites. This study provides evidence of subtle abnormalities in neuronal function in regions of the white matter in meditators. PMID:23536796

Effects of intensive cognitive-behavioral therapy on cingulate neurochemistry in obsessive–compulsive disorder

PubMed Central

O'Neill, Joseph; Gorbis, Eda; Feusner, Jamie D.; Yip, Jenny C.; Chang, Susanna; Maidment, Karron M.; Levitt, Jennifer G.; Salamon, Noriko; Ringman, John M.; Saxena, Sanjaya

2013-01-01

The neurophysiological bases of cognitive-behavioral therapy (CBT) for obsessive–compulsive disorder (OCD) are incompletely understood. Previous studies, though sparse, implicate metabolic changes in pregenual anterior cingulate cortex (pACC) and anterior middle cingulate cortex (aMCC) as neural correlates of response to CBT. The goal of this pilot study was to determine the relationship between levels of the neurochemically interlinked metabolites glutamate + glutamine (Glx) and N-acetyl-aspartate + N-acetyl-aspartyl-glutamate (tNAA) in pACC and aMCC to pretreatment OCD diagnostic status and OCD response to CBT. Proton magnetic resonance spectroscopic imaging (1H MRSI) was acquired from pACC and aMCC in 10 OCD patients at baseline, 8 of whom had a repeat scan after 4 weeks of intensive CBT. pACC was also scanned (baseline only) in 8 age-matched healthy controls. OCD symptoms improved markedly in 8/8 patients after CBT. In right pACC, tNAA was significantly lower in OCD patients than controls at baseline and then increased significantly after CBT. Baseline tNAA also correlated with post-CBT change in OCD symptom severity. In left aMCC, Glx decreased significantly after intensive CBT. These findings add to evidence implicating the pACC and aMCC as loci of the metabolic effects of CBT in OCD, particularly effects on glutamatergic and N-acetyl compounds. Moreover, these metabolic responses occurred after just 4 weeks of intensive CBT, compared to 3 months for standard weekly CBT. Baseline levels of tNAA in the pACC may be associated with response to CBT for OCD. Lateralization of metabolite effects of CBT, previously observed in subcortical nuclei and white matter, may also occur in cingulate cortex. Tentative mechanisms for these effects are discussed. Comorbid depressive symptoms in OCD patients may have contributed to metabolite effects, although baseline and post-CBT change in depression ratings varied with choline-compounds and myo-inositol rather than Glx or tNAA. PMID:23290560

Insular Cortex Metabolite Changes in Obstructive Sleep Apnea

PubMed Central

Yadav, Santosh K.; Kumar, Rajesh; Macey, Paul M.; Woo, Mary A.; Yan-Go, Frisca L.; Harper, Ronald M.

2014-01-01

Study Objective: Adults with obstructive sleep apnea (OSA) show significant autonomic and neuropsychologic deficits, which may derive from damage to insular regions that serve those functions. The aim was to assess glial and neuronal status from anterior insular metabolites in OSA versus controls, using proton magnetic resonance spectroscopy (PMRS), and thus to provide insights for neuroprotection against tissue changes, and to reduce injury consequences. Design: Cross-sectional study. Setting: University-based medical center. Participants: Thirty-six patients with OSA, 53 controls. Interventions: None. Measurements and Results: We performed PMRS in bilateral anterior insulae using a 3.0-Tesla magnetic resonance imaging scanner, calculated N-acetylaspartate/creatine (NAA/Cr), choline/creatine (Cho/Cr), myo-inositol/creatine (MI/Cr), and MI/NAA metabolite ratios, and examined daytime sleepiness (Epworth Sleepiness Scale, ESS), sleep quality (Pittsburgh Sleep Quality Index, PSQI), and neuropsychologic status (Beck Depression Inventory II [BDI-II] and Beck Anxiety Inventory [BAI]). Body mass index, BAI, BDI-II, PSQI, and ESS significantly differed between groups. NAA/ Cr ratios were significantly reduced bilaterally, and left-sided MI/Cr and MI/NAA ratios were increased in OSA over controls. Significant positive correlations emerged between left insular MI/Cr ratios and apnea-hypopnea index values, right insular Cho/Cr ratios and BDI-II and BAI scores, and negative correlations appeared between left insular NAA/Cr ratios and PSQI scores and between right-side MI/Cr ratios and baseline and nadir change in O2 saturation. Conclusions: Adults with obstructive sleep apnea showed bilaterally reduced N-acetylaspartate and left-side increased myo-inositol anterior insular metabolites, indicating neuronal damage and increased glial activation, respectively, which may contribute to abnormal autonomic and neuropsychologic functions in the condition. The activated glial status likely indicates increased inflammatory action that may induce more neuronal injury, and suggests separate approaches for glial and neuronal protection. Citation: Yadav SK, Kumar R, Macey PM, Woo MA, Yan-Go FL, Harper RM. Insular cortex metabolite changes in obstructive sleep apnea. SLEEP 2014;37(5):951-958. PMID:24790274

Proton magnetic resonance spectroscopy as a probe into the pathophysiology of autism spectrum disorders (ASD): a review.

PubMed

Baruth, Joshua M; Wall, Christopher A; Patterson, Marc C; Port, John D

2013-04-01

Proton magnetic resonance spectroscopy ((1) H-MRS) is a safe, noninvasive way of quantifying in vivo biochemical and metabolite concentration levels in individuals with Autism Spectrum Disorders (ASD). Findings to date suggest ASD is associated with widespread reduction in N-acetylaspartate (NAA), creatine plus phosphocreatine (Cr), choline-containing compounds (Cho), myo-inositol (mI), and glutamate plus glutamine plus gamma-Aminobutyric Acid (Glx); however, variable findings, and even substantial increases, are not uncommon depending on the study and/or region-of-interest. Widespread reduction of NAA, Cr, Cho, mI, and Glx in ASD likely reflects impaired neuronal function and/or metabolism related to abnormal neurodevelopmental processes. Future studies should attempt to relate (1) H-MRS findings to histological findings and control for variability in subject age and functioning level; this would assist in evaluating the relationship between (1) H-MRS metabolic levels and neuronal and glial cell densities, as well as neurodevelopmental process associated with ASD. Furthermore, more longitudinal (1) H-MRS studies are needed in both control and ASD subjects to attempt to standardize metabolite levels across different developmental periods in well-defined endophenotypes. This will provide for a standard rubric for which metabolic aberrations (as well as treatment responses) can be measured. With higher magnetic field strengths and spectral-editing techniques capable of quantifying less-concentrated metabolites, (1) H-MRS will continue to be an important tool in ASD research. © 2013 International Society for Autism Research, Wiley Periodicals, Inc.