Search results for "GLUTAMINE"

Glutamine transport by the blood-brain barrier: a possible mechanism for nitrogen removal

1998

Glutamine and glutamate transport activities were measured in isolated luminal and abluminal plasma membrane vesicles derived from bovine brain endothelial cells. Facilitative systems for glutamine and glutamate were almost exclusively located in luminal-enriched membranes. The facilitative glutamine carrier was neither sensitive to 2-aminobicyclo(2,2,1)heptane-2-carboxylic acid inhibition nor did it participate in accelerated amino acid exchange; it therefore appeared to be distinct from the neutral amino acid transport system L1. Two Na-dependent glutamine transporters were found in abluminal-enriched membranes: systems A and N. System N accounted for approximately 80% of Na-dependent glu…

Ataxin-1 and ataxin-2 intermediate-length PolyQ expansions in amyotrophic lateral sclerosis.

2012

ABSTRACT Objective: Recent evidence suggests that intermediate-length polyglutamine (PolyQ) expansions in the ataxin-2 ( ATXN-2 ) gene are a risk factor for amyotrophic lateral sclerosis (ALS). This work was undertaken with the aim to investigate the frequency of ataxin-1 ( ATXN-1 ) and ATXN-2 PolyQ expansions in a cohort of patients with sporadic ALS (sALS) and patients with familial ALS (fALS) from southern Italy. Methods: We assessed the PolyQ lengths of ATXN-1 and ATXN-2 in 405 patients with sALS, 13 patients with fALS, and 296 unrelated controls without history of neurodegenerative disorders. Results: We found significantly higher intermediate PolyQ expansions ≥32 for ATXN-1 alleles an…

Glutamatergic hypofunction in medication-free major depression: Secondary effects of affective diagnosis and relationship to peripheral glutaminase.

2018

BackgroundThere is uncertainty as to whether alterations in glutamatergic function in affective disorders differ between unipolar and bipolar disorders and between depressive and euthymic states. Additionally, there are currently no available blood-based markers of central glutamatergic function to support clinical diagnosis and aid brain based investigations. MethodsIn this study, we measured levels of glutamate in the dorsal anterior cingulate cortex in-vivo using 1H-Magnetic Resonance Spectroscopy in medication free unipolar and bipolar patients (n=29, 20 unipolar and 9 bipolar) experiencing a major depressive episode, in comparison with a group of matched healthy controls (n=20). We als…

Amino acids requirements of measles virus in HeLa cells.

1973

A low plating efficiency for measles virus was obtained when arginine, threonine and isoleucine were omitted from Eagle's basal medium and a stimulatory effect on the plaque production was produced by increasing the concentration up to 0.5 mm of arginine and glutamine. However, of all amino acids in Eagle's basal medium, only methionine was found to be essential for the synthesis of infectious progeny virus. Omission of any one of the other amino acids from the culture medium permitted limited virus production, but none whatever could be detected in the absence of mediummethionine. Moreover, when methionine was restored to infected cultures after 24 hours of deprivation, release of virus be…

Influence of N-acetylcysteine on hepatic amino acid metabolism in patients undergoing orthotopic liver transplantation

2001

Experimental treatment with the antioxidant and glutathione precursor N-acetylcysteine (NAC) has been performed in orthotopic liver transplantation (OLT) to reduce reperfusion injury. To investigate the effect of NAC on the hepatic and intestinal amino acid metabolism, intraoperative amino acid exchange rates were studied in liver transplant recipients with high dose NAC treatment (n = 10) and in control patients (n = 9). Treatment with NAC was found to cause a loss of amino acids and increased urea nitrogen release from the liver graft. The net balance of most amino acids was shifted to increased hepatic release or decreased hepatic uptake. The initial cumulative splanchnic release of all …

Gene amplification in fibroblasts from ataxia telangiectasia (AT) patients and in X-ray hypersensitive AT-like Chinese hamster mutants.

2001

In search of functions involved in the regulation of gene amplification, and given the relevance of chromosome breakage in initiating the process, we analyzed the gene amplification ability of cells hypersensitive to inducers of DNA double-strand breaks and defective in cell cycle control: two human fibroblast strains derived from patients affected by ataxia telangiectasia (AT) and two hamster mutant cell lines belonging to complementation group XRCC8 of the rodent X-ray-sensitive mutants. These mutants are considered hamster models of AT cells. To measure gene amplification, the frequency and the rate of occurrence of N-(phosphonacetyl)-L-aspartate resistant cells were determined. In both …

Detection of a Single Gene Encoding Glutamine Synthetase in Sinapis alba (L.)

1991

Summary Ion-exchange chromatography of glutamine synthetase polypeptides (GS; EC 6.3.1.2) from green leaves and the roots of Sinapis alba yielded identical elution patterns. This is likewise true for GS from etiolated cotyledons. As we have previously demonstrated the identity of GS-enzymes from etiolated and green leaf tissues, the obviously very similar charge properties of GS-proteins indicate the eventual existence of only one type of GS in all mustard plant organs. To further prove this possibility, Southern blot analysis of mustard DNA was carried out using hybridization probes specific to different GS-isoforms. Concluding from the relative strength of the hybridization signals, the G…

Glutamine synthetase isozymes in germinating barley seeds

1993

Glutamine synthetase (GS; EC 6.3.1.2) is a key enzyme of ammonia assimilation in higher plants. In the present study the subunit composition and localization of GS in germinating barley (Hordeum vulgare) seed have been clarified. Analysis of the GS polypeptide composition by immunoblotting revealed two different polypeptides. A and B, with a molecular mass of 42 and 40 kDa, respectively. In the scutellum subunit A was already present in the ungerminated seed and remained unchanged, whereas subunit B appeared on day 2 and increased about 5-fold during germination. Polypeptide B also appeared later during germination in the aleurone layer, roots and weakly in the etiolated shoots. By immunogo…

UNDERSTANDING THE RELATIONSHIP BETWEEN NORMAL FUNCTION AND ABERRANT AGGREGATION: THE CASE OF ATAXIN-3

2020

Analysis of reproductive toxicity and classification of glufosinate-ammonium.

2005

CONCLUSION REGARDING CLASSIFICATION OF GLUFOSINATE-AMMONIUM: Science Partners' Evaluation Group (Evaluation Group) has conducted an independent analysis of the herbicide glufosinate-ammonium (GA) relative to its potential to cause reproductive toxicity in humans. Further, the Evaluation Group has evaluated the implementation of Annex 6 of Commission Directive 2001/59/EC (28th ATP of Council Directive 67/548/EEC) and Council Directive 91/414/EEC, with respect to classification of chemicals posing potential reproductive hazards. After consideration of all information available to us relevant to the potential of glufosinate-ammonium (GA) to cause reproductive toxicity, the Science Partners Eva…