AMP deaminase, 5′-nucleotidase and adenosine deaminase in rat myocardial tissue in myocardial infarction and hypothermia

Summary AMP deaminase, 5-nucleotidase and adenosine deaminase have been estimated in skeletal muscle and myocardial tissue in normal rats and in rats subjected to experimental myocardial infarction or hypothermia. A difference in the enzyme distribution was found between the right and left ventricles in the normal rat. A decrease in the activity of 5-nucleotidase and an increase in the activity of adenosine deaminase were observed in infarcted myocardial tissue. The activity of all 3 enzymes was found to be depressed in the myocardium in rats subjected to hypothermia. These results are discussed in relation to adenosine production and its beneficial effects.     

Human Genome and Diseases:¶Double-strand breaks and translocations in cancer

The correct repair of double-strand breaks (DSBs) is essential for the genomic integrity of a cell, as inappropriate repair can lead to chromosomal rearrangements such as translocations. In many hematologic cancers and sarcomas, translocations are the etiological factor in tumorigenesis, resulting in either the deregulation of a proto-oncogene or the expression of a fusion protein with transforming properties. Mammalian cells are able to repair DSBs by pathways involving homologous recombination and nonhomologous end-joining. The analysis of translocation breakpoints in a number of cancers and the development of model translocation systems are beginning to shed light on specific DSB repair pathway(s) responsible for the improper repair of broken chromosomes. Received 19 June 2001; received after revision 6 September 2001; accepted 11 September 2001     

β-Endorphin in normozoospermic and pathologic human semen

Summary -Endorphin was estimated in normozoospermic, oligozoospermic and azoospermic human semen. The mean amount in normozoospermic specimens was 278.6±43.6 (SE) pg/ml while in the others only 191.1±25 pg/ml. Both values are significantly higher than those present in the blood.     

Biosynthesis ofα- andβ-ecdysone by the CrayfishOrconectes limosus in vivo and by its Y-Organs in vitro

Summary - and -ecdysone were synthesized from labelled cholesterol by premolt crayfish in vivo and by their Y-organs in vitro.     

Age- and sex-related differences in the content of prothymosinα in rat tissues

Differences in the tissue content of prothymosin during the early postnatal development of male and female rats are reported. Thymus and spleen have been found to contain significantly higher amounts of prothymosin in the newborn and prepubertal animals, as compared to adults, whereas liver has been found to contain low levels of prothymosin throughout development. These findings indicate a functional association of prothymosin with the proliferating lymphoid tissues of the young rat.     

Allozyme polymorphism and linkage disequilibrium ofAdh and α-Gpdh loci in wine cellar and field populations ofDrosophila melanogaster

Summary Over three years, theAdh and -Gpdh loci have been studied in two cellar populations ofDrosophila melanogaster and in two field populations which were each near to one of the cellars. Analyses of gene frequencies indicate that the divergence among subpopulations is greater in theAdh locus than in the -Gpdh locus. Selection for or againstAdh ^S allele acting on theIn(2L)t inversion influences of the -Gpdh alleles. This phenomenon may contribute to explain the maintenance of theAdh and -Gpdh polymorphism and of theIn(2L)t inversion.     

Chemistry in Rozier's Journal.—VI and VII

In 1783 John Michell published a note entitled ‘On the Means of Discovering the Distance, Magnitude etc. of the Fixed Stars, in Consequence of the Diminution of the Velocity of their Light’, but it was Christian Doppler who in 1842 for the first time formulated the principle (now generally known by his name): If a source of sound or light is in motion relative to an observer, or an observer in motion relative to a source, the period of the waves received by the observer will be different from the period of the waves emitted by the source. The acoustical Doppler principle was verified in 1845 by Buys-Ballot's experiments and by Ernst Mach (in the laboratory, using a Rotationsapparat (1860)). H. Fizeau proposed to verify the optical Doppler principle by measuring the shift of lines in the spectra of stars (1848). This was carried out by William Huggins (1868 ff.), and H. C. Vogel and led to exact results in 1892. The Doppler effect with canal rays was shown by Johannes Stark in 1905.     

Wnt–Notch signalling crosstalk in development and disease

The Notch and Wnt pathways are two of only a handful of highly conserved signalling pathways that control cell-fate decisions during animal development (Pires-daSilva and Sommer in Nat Rev Genet 4: 39–49, 2003). These two pathways are required together to regulate many aspects of metazoan development, ranging from germ layer patterning in sea urchins (Peter and Davidson in Nature 474: 635–639, 2011) to the formation and patterning of the fly wing (Axelrod et al in Science 271:1826–1832, 1996; Micchelli et al in Development 124:1485–1495, 1997; Rulifson et al in Nature 384:72–74, 1996), the spacing of the ciliated cells in the epidermis of frog embryos (Collu et al in Development 139:4405–4415, 2012) and the maintenance and turnover of the skin, gut lining and mammary gland in mammals (Clayton et al in Nature 446:185–189, 2007; Clevers in Cell 154:274–284, 2013; Doupe et al in Dev Cell 18:317–323, 2010; Lim et al in Science 342:1226–1230, 2013; Lowell et al in Curr Biol 10:491–500, 2000; van et al in Nature 435:959–963, 2005; Yin et al in Nat Methods 11:106–112, 2013). In addition, many diseases, including several cancers, are caused by aberrant signalling through the two pathways (Bolós et al in Endocr Rev 28: 339–363, 2007; Clevers in Cell 127: 469–480, 2006). In this review, we will outline the two signalling pathways, describe the different points of interaction between them, and cover how these interactions influence development and disease.     

Grasping the spirit in nature: Anschauung in Ørsted's epistemology of science and beauty

The intersection between art, poetry, philosophy and science was the leitmotif which guided the lives and careers of romantic natural philosophers including that of the Danish natural philosopher, H. C. Ørsted. A simple model of Ørsted’s career would be one in which it was framed by two periods of philosophical speculation: the youth’s curious and idealistic interest in new attractive thoughts and the experienced man’s mature reflections at the end of his life. We suggest that a closer look at the epistemological aspects of his works on the theory of beauty reveals a connection between this late work and his early philosophical work including experimental philosophy, but also with the work in teaching and textbook writing, that lies in between. The latter includes Ørsted’s view on the application of mathematics in natural philosophy as well as his failed attempt at a genetic presentation of elementary geometry.     

NDRG2 is highly expressed in pancreatic β cells and involved in protection against lipotoxicity

The N-myc downstream-regulated gene 2 (NDRG2) is involved in cell differentiation and apoptosis, but its function in the pancreas remains to be established. Herein we examine the expression and function of NDRG2 in the endocrine pancreas. NDRG2 immunoreactivity was localized mainly in the cytoplasm of pancreatic β cells. When β-TC3 cells were exposed chronically to high levels of free fatty acid (FFA), cell viability was impaired, and Akt and NDRG2 phosphorylation were reduced. NDRG2 is a potential substrate of protein kinase Akt. Overexpression of constitutively active Akt enhanced NDRG2 phosphorylation and abolished the apoptosis induced by FFA in β-TC3 cells, whereas NDRG2 knock-down attenuated Akt-mediated protection of β cells against fatty acid-triggered apoptosis. Collectively, these data indicate that NDRG2 acts as a key molecule in pancreatic β cells and is involved in the Akt-mediated protection of β cells against lipotoxicity.     

Biogenesis of β-barrel membrane proteins in bacteria and eukaryotes: evolutionary conservation and divergence

Membrane-embedded β-barrel proteins span the membrane via multiple amphipathic β-strands arranged in a cylindrical shape. These proteins are found in the outer membranes of Gram-negative bacteria, mitochondria and chloroplasts. This situation is thought to reflect the evolutionary origin of mitochondria and chloroplasts from Gram-negative bacterial endosymbionts. β-barrel proteins fulfil a variety of functions; among them are pore-forming proteins that allow the flux of metabolites across the membrane by passive diffusion, active transporters of siderophores, enzymes, structural proteins, and proteins that mediate protein translocation across or insertion into membranes. The biogenesis process of these proteins combines evolutionary conservation of the central elements with some noticeable differences in signals and machineries. This review summarizes our current knowledge of the functions and biogenesis of this special family of proteins.     

Vital Instability: Life and Free Will in Physics and Physiology, 1860–1880

During the period 1860–1880, a number of physicists and mathematicians, including Maxwell, Stewart, Cournot and Boussinesq, used theories formulated in terms of physics to argue that the mind, the soul or a vital principle could have an impact on the body. This paper shows that what was primarily at stake for these authors was a concern about the irreducibility of life and the mind to physics, and that their theories can be regarded primarily as reactions to the law of conservation of energy, which was used among others by Helmholtz and Du Bois-Reymond as an argument against the possibility of vital and mental causes in physiology. In light of this development, Maxwell, Stewart, Cournot and Boussinesq showed that it was still possible to argue for the irreducibility of life and the mind to physics, through an appeal to instability or indeterminism in physics: if the body is an unstable or physically indeterministic system, an immaterial principle can act through triggering or directing motions in the body, without violating the laws of physics.     

Reduction of adenylylsulfate and 3′-phosphoadenylylsulfate in phototrophic bacteria

Summary Extracts of 14 species of phototrophic bacteria, partly grown with different sulfur compounds, were tested for their ability to form volatile sulfur compounds from adenylylsulfate (APS) and 3-phosphoadenylylsulfate (PAPS). The Rhodospirillum species showed marked activities with both APS and PAPS while the Rhodopseudomonas species seem to prefer PAPS. the Chromatiaceae exhibited the strongest activities with APS, whereas Chlorobium limicola had equally high activity with PAPS.We thank J. F. Imhoff for skilful assistance and the Deutsche Forschungsgemeinschaft for financial support.     

Levels ofα 1 in the spring and autumn seasons

Summary In a group of 84 pairs of 11-year-old children of both sexes, the level of the ₁-antitrypsin ( ₁-AT) were ascertained in the autumn and spring. Although the mean levels of ₁-AT in the two seasons hardly differed, the highly significant seasonal changes in the distribution curves of ₁-AT values were noted in boys, whereas the levels showed higher stability in girls.     

Development of γ-glutamylcysteine synthetase and oxoprolinase in rat kidney

Summary -Glutamylcysteine synthetase is present in barely detectable amounts in foetal kidney. Its activity starts to increase in postnatal life. In contrast, oxoproline is already found in significant quantities in the foetal tissue. Both enzymes show marked elevation in activities during the weaning period.Acknowledgment. The work was supported by a research grant awarded by the Committee on Research and Conference Grants, University of Hong Kong.