Stereoisomeric flavour compounds XXXV: Chiral aroma compounds of sherry I. Optically pure stereoisomers of solerone and solerole

The enantioseparation of the sherry aroma components 5-oxo-4-hydroxyhexanoic acid γ-lactone (solerone) and 4,5-dihydroxyhexanoic acid γ-lactone (solerole) is achieved, using Chiraspher (Merck) as the chiral HPLC phase and the optical purity ascertained directly by HRGC with heptakis(3-O-acetyl-2,6-di-O-pentyl)-β-cyclodextrin (Lipodex D) as the chiral stationary phase. The absolute configurations of 4,5-dihydroxyhexanoic acid γ-lactones are assigned by ¹H-NMR spectral data of diastereomeric α-methoxy-α-trifluoromethylphenylacetic acid (MTPA) esters, according to Mosher's model. Sensory qualities of the isomers are given.     

Genetic Analysis of the Epidermal Differentiation Complex (EDC) on Human Chromosome 1q21: Chromosomal Orientation, New Markers, and a 6-Mb YAC Contig

The epidermal differentiation complex (EDC) unites a remarkable number of structurally, functionally, and evolutionarily related genes that play an important role in terminal differentiation of the human epidermis. It is localized within 2.05 Mb of region q21 on human chromosome 1. We have identified and characterized 24 yeast artificial chromosome (YAC) clones by mapping individual EDC genes, sequence-tagged site (STS) markers (D1S305, D1S442, D1S498, D1S1664), and 10 new region-specific probes (D1S3619–D1S3628). Here we present a contig that covers about 6 Mb of 1q21 including the entire EDC. Fluorescencein situhybridization on metaphase chromosomes with two YACs flanking the EDC determined its chromosomal orientation and established, in conjunction with physical mapping results, the following order of genes and STSs: 1cen–D1S442–D1S498–S100A10–THH–FLG–D1S1664–IVL–SPRR3–SPRR1–SPRR2–LOR–S100A9–S100A8–S100A7–S100A6–S100A5–S100A4–S100A3–S100A2–S100A1–D1S305–1qtel. These integrated physical, cytogenetic, and genetic mapping data will be useful for linkage analyses of diseases associated with region 1q21 and for the identification of novel genes and regulatory elements in the EDC.     

Promises and limits of an agency perspective in evolutionary developmental biology

An agent-based perspective in the study of complex systems is well established in diverse disciplines, yet is only beginning to be applied to evolutionary developmental biology. In this essay, we begin by defining agency and associated terminology formally. We then explore the assumptions and predictions of an agency perspective, apply these to select processes and key concept areas relevant to practitioners of evolutionary developmental biology, and consider the potential epistemic roles that an agency perspective might play in evo devo. Throughout, we discuss evidence supportive of agential dynamics in biological systems relevant to evo devo and explore where agency thinking may enrich the explanatory reach of research efforts in evolutionary developmental biology.     

Using averaged models from 4D ultrasound strain imaging allows to significantly differentiate local wall strains in calcified regions of abdominal aortic aneurysms

Abdominal aortic aneurysms are a degenerative disease of the aorta associated with high mortality. To date, in vivo information to characterize the individual elastic properties of the aneurysm wall in terms of rupture risk is lacking. We have used time-resolved 3D ultrasound strain imaging to calculate spatially resolved in-plane strain distributions characterized by mean and local maximum strains, as well as indices of local variations in strains. Likewise, we here present a method to generate averaged models from multiple segmentations. Strains were then calculated for single segmentations and averaged models. After registration with aneurysm geometries based on CT-A imaging, local strains were divided into two groups with and without calcifications and compared. Geometry comparison from both imaging modalities showed good agreement with a root mean squared error of 1.22 ± 0.15 mm and Hausdorff Distance of 5.45 ± 1.56 mm (mean ± sd, respectively). Using averaged models, circumferential strains in areas with calcifications were 23.2 ± 11.7% (mean ± sd) smaller and significantly distinguishable at the 5% level from areas without calcifications. For single segmentations, this was possible only in 50% of cases. The areas without calcifications showed greater heterogeneity, larger maximum strains, and smaller strain ratios when computed by use of the averaged models. Using these averaged models, reliable conclusions can be made about the local elastic properties of individual aneurysm (and long-term observations of their change), rather than just group comparisons. This is an important prerequisite for clinical application and provides qualitatively new information about the change of an abdominal aortic aneurysm in the course of disease progression compared to the diameter criterion.

     

On-line measurements of culture fluorescence: Method and application

Summary In this paper a new probe allowing the measurement of NAD(P)H-dependent culture fluorescence in a bioreactor is presented. This sterilizable probe can be inserted in every bioreactor using a standard fitting of 25 mm. Under well defined conditions high specificity and sensitivity as well as high stability are further advantages of this probe. Application examples are given to demonstrate the operation possibilities of this fluorescence probe. In batch growth the culture fluorescence can be used for on-line estimation of biomass concentration. Metabolic alterations due to substrate of oxygen deficiency can easily be detected by fluorometric measurements. In kinetic studies the fluorescence probe is of great use because of a very small time delay.     

Genetic control of human apolipoprotein E polymorphism: Comparison of one-and two-dimensional techniques of isoprotein analysis

Summary Genetic polymorphism of human apolipoprotein E (apo E) has previously been demonstrated by one-dimensional isoelectric focusing (Utermann et al. 1977b) and by two-dimensional electrophoresis of apolipoproteins (Zannis et al. 1981), but the relationship between the results obtained by these methods remained unclear. We therefore performed comparative phenotyping by one-dimensional and two-dimensional electrophoresis. Apoproteins from very low-density lipoproteins (apo VLDL) prepared by ultracentrifugation or from an apo Erich lipoprotein fraction prepared by heparin/Mg⁺⁺ precipitation, were used as a source of apo E. Six common phenotypes designated apo E-4/4, apo E-N/N, apo E-D/D, apo E-4/N, apo E-4/D, and apo E-N/D were differentiated irrespective of the technique used or the source of apolipoproteins, but the two-dimensional electrophoresis of apo VLDL and apo VLDL which had been treated with neuraminidase was the key for the correct genetic interpretation of those phenotypes exhibiting the E4 isoform of the protein. Each phenotype is characterized by the presence of either one or two of three major isoforms E2, E3, and E4 and by the presence of several minor sialylated forms of these proteins (apo E_s) that have higher apparent molecular weights. The unsialylated major isoform apo E2 does not only differ in charge but also has a higher apparent mol.wt. (about 34,500) than the major isoforms apo E3 and apo E4 (mol. wt. about 33,000). Family studies including 90 matings with a total of 203 offspring confirmed the genetic one locus model of Zannis et al. (1981). Apo E phenotypes are controlled by three autosomal codominant alleles apo E^d, apo Eⁿ, and apo E⁴ that specify for the E2, E3, and E4 isoforms respectively. Phenotypes apo E-D/D,-N/N, and-4/4 represent homozygotes and phenotypes apo E-4/N,-4/D, and-N/D heterozygotes for these alleles.The frequencies of apo E alleles in 1031 blood donors were apo E⁴=0.150, apo Eⁿ=0.773, and apo E^d=0.077. Homozygosity for the allele apo E^d is associated with hyperlipoproteinemia type III. Hence a large number of the population (about 1%) are at risk for this specific lipoprotein disorder that is associated with premature atherosclerosis and xanthomatosis.     

Intracellular concentrations of phenylalanine,tyrosine and α-aminobutyric acid in 13 homozybotes and 19 heterozygotes for phenylketonuria (PKU) compared with 26 normals

Summary Intracellular concentrations of phenylalanine, tyrosine, -aminobutyric acid, and seven other aminoacids (glycine, alanine, valine, cystine, methionine, isoleucine, leucine) were measured in lymphocytes of 13 homozygotes and 19 heterozygotes for phenylketonuria and in lymphocytes of 26 normals. Intracellular concentrations for phenylalanine, tyrosine, and -aminobutyric acid were significantly higher in homo- and heterozygotes than in normals (P<0.001; P<0.01). For the other seven aminoacids there were no or only questionable differences. Between homo-and heterozygotes there was no difference in any of the aminoacids. The intracellular phenylalanine: tyrosine ratio was essentially the same in all three groups of individuals. There was no correlation between intracellular phenylalanine above or below 10nmol/10⁶ cells and IQ in heterozygotes. The same is true for phenylalanine: tyrosine ratio greater or smaller than 1. In homozygotes there was no correlation between intracellular phenylalanine and age—to which DQ/IQ is correlated. There was no significant difference in intracellular phenylalanine between homozygotes with blood levels above and below 908 mol/l (15 mg/100 ml) at the time of blood sampling and no correlation between intra- and extracellular phenylalanine concentrations.Among the 26 normals there were only two with intracellular phenylalanine above 10 nmol/10⁶ cells, both showing phenylalanine loading test curves suggestive of heterozygosity.The results are discussed and important functions of the cell wall are proposed. The formation of an abnormal unknown intracellular metabolite being the real noxious agent could explain the incomparably different degrees of brain dysfunction in individuals with equal though elevated intracellular phenylalanine concentrations, i.e., homozygotes and heterozygotes for PKU.     

Territory Defence in Black Redstarts,Phoenicurus ochruros: Effects of Intruder and Owner Age?

European black redstarts, Phoenicurus ochruros, vigorously defend all-purpose territories and exhibit delayed plumage maturation, most subadult males looking exactly female-like in their first breeding season. We tested the hypotheses that such dull subadult male plumages are beneficial in order to reduce aggression of adult males either by deception or by honest signalling of subordinance status, and that, in turn, conspicuous (adult) plumage colorations are able to intimidate contenders because they act as a signal of fighting ability and aggressive motivation. Adult and dull yearling black redstart territory owners were confronted with intruders mimicked by stuffed mounts of either a conspicuous adult or a dull subadult male. Our results do not support the hypotheses tested: dull plumages of young intruders did not reduce aggression from adult territory owners and aggressiveness towards intruders was significantly higher in yearling territory owners as compared with adult owners. Conspicuous intruders did not deter dull territory owners and we found no indications that conspicuous male coloration is a signal of fighting ability or aggressive motivation in this species. Instead, the amount of aggressive response to intruders showed considerable individual variance within age classes regardless of the plumage of the intruder and the status of the owner.