Acyl-CoA: glycine N-acyltransferase: in vitro studies on the glycine conjugation of straight- and branched-chained acyl-CoA esters in human liver

Apparent kinetic constants (Km and Vmax values) were determined for human liver acyl-CoA: glycine acyltransferase (glycine-N-acylase) towards isobutyryl-CoA, 2-methyl butyryl-CoA, isovaleryl-CoA, butyryl-CoA, hexanoyl-CoA, octanoyl-CoA, and decanoyl-CoA. These acyl-CoA esters were selected because of their relevance to the human diseases with cellular accumulation of these esters, i.e., especially to metabolic defects in the acyl-CoA dehydrogenation steps of the branched-chain amino acids, lysine, 5-hydroxy lysine, tryptophan, and fatty acid oxidation pathways. With the acyl-CoA ester as the fixed substrate, the Km value for glycine ranged from 0.5 to 2.9 mole/liter, and with glycine as fixed substrate, the Km values for the acyl-CoA esters varied from 0.3 to 5.6 mmole/liter. It is concluded that the substrate concentration is decisive for the glycine conjugate formation and that the occurrence in urine of acylglycines reflects an intramitochondrial accumulation of the corresponding acyl-CoA ester.     

Rebound effects of price differences

Goal, Scope and Background  Traditionally, comparative life cycle assessments (LCA) have not considered rebound effects, for instance in case of significant price differences among the compared products. No justifications have been made for this delimitation in scope. This article shows that price differences and the consequent effects of marginal consumer expenditure may influence the conclusions of comparative LCA significantly. We also show that considerations about rebound effects of price differences can be included in LCAs. Methods  The direct rebound effect of a price difference is marginal consumption. Based on statistical data on private consumption in different income groups (Statistics Denmark 2005a, 2005b), the present article provides an estimate of how an average Danish household will spend an additional 1 DKK for further consumer goods, when the household has gained money from choosing a cheaper product alternative. The approach is to use marginal income changes and the following changes in consumption patterns as an expression for marginal consumption. Secondly, the environmental impact potentials related to this marginal consumption are estimated by the use of environmental impact intensity data from an IO-LCA database (Weidema et al. 2005). Finally, it is discussed whether, and in which ways the conclusions of comparative LCAs can be affected by including the price difference between product alternatives. This is elucidated in a case study of a comparative LCA screening of two different kinds of Danish cheese products (Fricke et al. 2004). Results  Car purchase and driving, use and maintenance of dwelling, clothing purchase and insurance constitutes the largest percentages of the marginal consumption. In a case study of two cheeses, the including the impact potentials related to the price difference results in significant changes in the total impact potentials. Considering the relatively small price difference of the two products, it is likely also to have a significant influence on the results of comparative LCAs more generally. Discussion  The influence of marginal consumption in comparative LCAs is relevant to consider in situations with large differences in the price of the product alternatives being compared, and in situations with minor differences in the impact potentials related to the alternatives. However, different uncertainties are linked to determining the pattern for marginal consumption and the environmental impact potential related to this. These are first of all related to the method used, but also include inaccurate data of consumption in households, aggregation and weighting of income groups, aggregation of product groups, estimation and size of the price difference, and the general applicability of the results. Conclusion  Incorporating marginal consumption in consequential LCAs is possible in practice. In the case study used, including the rebound effects of the price difference has a significant influence on the result of the comparative LCA, as the result for the impact categories acidification and nutrient enrichment changes in favour of the expensive product. Recommendations and Perspectives  It is recommended that the rebound effects of price differences should be included more frequently in LCAs. In order to ensure this, further research in marginal consumption and investment patterns and IO data for different countries or regions is required. Furthermore, this study does not consider the economic distributional consequences of buying an expensive product instead of a cheaper product (e.g. related to how the profit is spent by those who provided the product). It should also be noted, that more expensive products not necessarily result in less consumption, as those who provided the product also will spend the money they have earned from the sale. Ideally, these consequences should also be further investigated. Likewise, the development of databases to include marginal consumption in PC-tools is needed. In general, considerations of marginal consumption would favour expensive product alternatives, depending, however, on the type of consumer. ESS-Submission Editor: Dr. David Hunkeler (david.hunkeler@aquaplustech.ch)     

Genetic defects in fatty acid beta-oxidation and acyl-CoA dehydrogenases. Molecular pathogenesis and genotype-phenotype relationships.

Mitochondrial fatty acid oxidation deficiencies are due to genetic defects in enzymes of fatty acid beta-oxidation and transport proteins. Genetic defects have been identified in most of the genes where nearly all types of sequence variations (mutation types) have been associated with disease. In this paper, we will discuss the effects of the various types of sequence variations encountered and review current knowledge regarding the genotype-phenotype relationship, especially in patients with acyl-CoA dehydrogenase deficiencies where sufficient material exists for a meaningful discussion. Because mis-sense sequence variations are prevalent in these diseases, we will discuss the implications of these types of sequence variations on the processing and folding of mis-sense variant proteins. As the prevalent mis-sense variant K304E MCAD protein has been studied intensively, the investigations on biogenesis, stability and kinetic properties for this variant enzyme will be discussed in detail and used as a paradigm for the study of other mis-sense variant proteins. We conclude that the total effect of mis-sense sequence variations may comprise an invariable--sequence variation specific--effect on the catalytic parameters and a conditional effect, which is dependent on cellular, physiological and genetic factors other than the sequence variation itself.     

Nucleotide sequence of a DRw10 beta chain cDNA clone. Identity of the third D region with that of the DRw53 allele of the beta 2 locus and as the probable site encoding a polymorphic MHC class II epitope

The nucleotide and inferred amino acid sequence of a DRw10 beta chain was obtained from cDNA clones isolated from a DR1, DRw10 heterozygous cell line. The sequence of this beta chain gene was distinctive, differing from those of all other defined DR types. The DRw10 beta chain gene was shown by transfection experiments to encode a polymorphic epitope recognized by mAb 109d6 that is also encoded by the DRw53 beta 2 chain gene. Comparison of the nucleotide sequence of both genes revealed that their third D regions (amino acids 67 to 73) were identical. This suggested first that the 109d6 epitope could be encoded by residues of this region, and second, that a putative gene conversion event transferred this sequence along with the information encoding the 109d6 epitope from a donor gene such as DRw53 beta 2. The sequence of the DRw10 beta chain gene was observed to be identical to that of clone pII beta 4 derived from the non-DR3 haplotype in the Raji cell line, which was also demonstrated to express the determinant recognized by antibody 109d6, suggesting that the typing of this cell line is HLA-DR3/DRw10. No evidence was found for the existence of a DR beta 2 chain gene product encoded by the DRw10 haplotype. The DRw10 haplotype was of particular interest because it was present along with a DR1 haplotype in the propositus who had rheumatoid arthritis, and was shared by the DR4-positive son of the propositus, who also had rheumatoid arthritis. This raised the possibility that the DRw10 haplotype, and most probably one or more specific conformations encoded by the DR beta chain, are involved in the definition of the disease susceptibility phenotype.     

Psychopathology in 7‐year‐old children with familial high risk of developing schizophrenia spectrum psychosis or bipolar disorder – The Danish High Risk and Resilience Study ‐ VIA 7, a population‐based cohort study

This study aimed to compare the psychopathological profiles of children at familial high risk of schizophrenia spectrum psychosis (FHR‐SZ) or bipolar disorder (FHR‐BP) with population‐based controls. We used Danish nationwide registers to retrieve a cohort of 522 seven‐year‐old children of parents with schizophrenia spectrum psychosis (N=202), bipolar disorder (N=120) or none of these disorders (N=200). Psychopathology was assessed by reports from multiple informants, including children, parents and teachers. Lifetime DSM‐IV diagnoses were ascertained by blinded raters through the Schedule for Affective Disorders and Schizophrenia for School‐Age Children. The dimensional assessment of psychopathology was performed by the Child Behavior Checklist, the Teacher's Report Form, a modified version of the ADHD‐Rating Scale, the Test Observation Form, and the State‐Trait Anxiety Inventory for Children. Current level of functioning was evaluated using the Children's Global Assessment Scale (CGAS). The prevalence of lifetime psychiatric diagnoses was significantly higher in both FHR‐SZ children (38.7%, odds ratio, OR=3.5, 95% confidence interval, CI: 2.2‐5.7, p < 0.001) and FHR‐BP children (35.6%, OR=3.1, 95% CI: 1.8‐5.3, p < 0.001) compared with controls (15.2%). FHR‐SZ children displayed significantly more dimensional psychopathology on all scales and subscales compared with controls except for the Anxious subscale of the Test Observation Form. FHR‐BP children showed higher levels of dimensional psychopathology on several scales and subscales compared with controls, but lower levels compared with FHR‐SZ children. Level of functioning was lower in both FHR‐SZ children (CGAS mean score = 68.2; 95% CI: 66.3‐70.2, p < 0.0001) and FHR‐BP children (73.7; 95% CI: 71.2‐76.3, p < 0.05) compared with controls (77.9; 95% CI: 75.9‐79.9). In conclusion, already at the age of seven, FHR‐SZ and FHR‐BP children show a higher prevalence of a broad spectrum of categorical and dimensional psychopathology compared with controls. These results emphasize the need for developing early intervention strategies towards this vulnerable group of children.     

Quantitative proteomics suggests metabolic reprogramming during ETHE1 deficiency

Deficiency of mitochondrial sulfur dioxygenase (ETHE1) causes the severe metabolic disorder ethylmalonic encephalopathy, which is characterized by early‐onset encephalopathy and defective cytochrome C oxidase because of hydrogen sulfide accumulation. Although the severe systemic consequences of the disorder are becoming clear, the molecular effects are not well defined. Therefore, for further elucidating the effects of ETHE1‐deficiency, we performed a large scale quantitative proteomics study on liver tissue from ETHE1‐deficient mice. Our results demonstrated a clear link between ETHE1‐deficiency and redox active proteins, as reflected by downregulation of several proteins related to oxidation‐reduction, such as different dehydrogenases and cytochrome P450 (CYP450) members. Furthermore, the protein data indicated impact of the ETHE1‐deficiency on metabolic reprogramming through upregulation of glycolytic enzymes and by altering several heterogeneous ribonucleoproteins, indicating novel link between ETHE1 and gene expression regulation. We also found increase in total protein acetylation level, pointing out the link between ETHE1 and acetylation, which is likely controlled by both redox state and cellular metabolites. These findings are relevant for understanding the complexity of the disease and may shed light on important functions influenced by ETHE1 deficiency and by the concomitant increase in the gaseous mediator hydrogen sulfide. All MS data have been deposited in the ProteomeXchange with the dataset identifiers PXD002741 ( http://proteomecentral.proteomexchange.org/dataset/PXD002741 ) and PXD002742 ( http://proteomecentral.proteomexchange.org/dataset/PXD002741 ).     

Noninvasive genetic sampling reveals intrasex territoriality in wolverines

Due to its conspicuous manifestations and its capacity to shape the configuration and dynamics of wild populations, territorial behavior has long intrigued ecologists. Territoriality and other animal interactions in situ have traditionally been studied via direct observations and telemetry. Here, we explore whether noninvasive genetic sampling, which is increasingly supplementing traditional field methods in ecological research, can reveal territorial behavior in an elusive carnivore, the wolverine (Gulo gulo). Using the locations of genotyped wolverine scat samples collected annually over a period of 12 years in central Norway, we test three predictions: (1) male home ranges constructed from noninvasive genetic sampling data are larger than those of females, (2) individuals avoid areas used by other conspecifics of the same sex (intrasexual territoriality), and (3) avoidance of same‐sex territories diminishes or disappears after the territory owner's death. Each of these predictions is substantiated by our results: sex‐specific differences in home range size and intrasexual territoriality in wolverine are patently reflected in the spatial and temporal configuration of noninvasively collected genetic samples. Our study confirms that wildlife monitoring programs can utilize the spatial information in noninvasive genetic sampling data to detect and quantify home ranges and social organization.     

The concentration of twelve elements in the anterior pituitary from human subjects and rats as measured by particle induced X-ray emission (PIXE)

The concentration of twelve elements—potassium, calcium, manganese, iron, cobalt, nickel, copper, zinc, arsenic, selenium, bromine, and rubidium—in anterior pituitaries from human subjects and rats was measured using Particle Induced X-ray Emission (PIXE). The human material included anterior pituitaries from 37 normal human subjects, 27 males and 10 females, all of whom died from traumatic lesions. Excluded from the investigations were persons with alcohol abuse, regular use of drugs, and babies younger than 1 year. For selenium, zinc, bromine, and to some extent copper, there was good correlation between the amounts found in anterior pituitaries from rats and human subjects. A significant difference between male and female rat pituitaries was observed for copper, iron, and rubidium, whereas for humans significant difference was only observed for manganese. Anterior pituitaries from human females contained generally more zinc than male glands, but the concentration of zinc in young males was higher than in females. The present study also indicates age related differences in the copper content in anterior pituitaries from human subjects, since pituitaries from humans between 15–45 years contained 25% more copper than those from younger or older persons. The opposite pattern was observed in males. For such elements as Cu, Fe, Mn, and Se, the content in the anterior pituitary from human subjects was 1.6–2 times that stated for other endocrine organs.