2,3-Dihydrolinderazulene,a new bioactive azulene pigment from the gorgonianAcalycigorgia sp.

Summary A new azulene pigment, 2,3-dihydrolinderazulene, has been isolated along with guaiazulene and linderazulene as bioactive metabolites from the gorgonianAcalycigorgia sp.     

2,3-Dihydrolinderazulene, a new bioactive azulene pigment from the gorgonian Acalycigorgia sp

A new azulene pigment, 2,3-dihydrolinderazulene, has been isolated along with guaiazulene and linderazulene as bioactive metabolites from the gorgonian Acalycigorgia sp.     

The infectivity of polyhedra of nuclear polyhedrosis virus (N.P.V.) after passage through gut of an insectpredator

Summary Polyhedral inclusion bodies (P.I.B.) of a nuclear polyhedrosis virus ofHeliothis punctigera (Lep.) were found in excreta ofNabis tasmanicus (Het.), a predator ofH. punctigera. An immunofluorescent counting method was used to estimate numbers of P.I.B. Bioassays demonstrated that no loss of infectivity occurred during passage through the gut.Acknowledgment. I am grateful for the comments and criticism offered by Dr D.E. Pinnock, I thank D.J. Cooper for preparation of materials for the immunofluorescent counting method and J. Hardy for supplying me with eggs ofH. punctigera; all of Department of Entomology, Waite Agricultural Research Institute, Glen Osmond, South Australia.     

Juvenile hormone catabolism inManduca sexta: Homologue selectivity of catabolism and identification of a diol-phosphate conjugate as a major end product

We studied time-dependent metabolism of (10R)-[³H] juvenile hormone (JH) III and (10R, 11S)-[³H]JH I injected intoManduca sexta larvae; the hormones are metabolized to polar metabolites, expecially the JH acid-diol, and an unknown. Products were analyzed using a reversed-phase liquid chromatography assay. (10R)-JH III is metabolized much more rapidly than (10R, 11S)-[³H]JH I, whether injected seperately or as a mixture of hormones. The unknown metabolites of JH I and JH III were identified as phosphate conjugates of JH I and JH III diol by tandem mass spectral analysis of isolated samples. The phosphate conjugate of JH I diol is the principle end product of JH I metabolism.     

Juvenile hormone I is the principal juvenile hormone in a hemipteran insect,Riptortus clavatus

Juvenile hormone I (JH I) was identified by combined gas chromatography/mass spectrometry as the predominant JH in the hemolymph of female adults of the bean bug,Riptortus clavatus (Thunberg) (Hemiptera: Alydidae). Among JH I, II, and III, JH I was the most effective hormone for inducing the synthesis of yolk proteins in diapause adults.     

Mitochondrial DNA variation in geographic populations of Colorado potato beetle,Leptinotarsa decemlineata (Coleoptera; Chrysomelidae)

Summary This study demonstrates variability in restriction enzyme cleavage sites of mitochondrial DNA (mtDNA) among four popalations of Colorado potato beetle (CPB). A suite of three enzymes (EcoRI,HpaI,PstI) was sufficient to discriminate among the populations tested. Individuals heteroplasmic for restriction enzyme patterns were found in some populations. Variability in CPB mtDNA should prove useful in efforts to trace the origin and dispersal of the species in North America.     

Identification of teleost gonadotrope cells using methallibure (I.C.I. 33, 828) and thiourea

Zusammenfassung Die versuchsweise Identifizierung gonadotroper Zellen der Teleostier-Hypophyse (Plectoplites ambiguus) gelang nach Behandlung mit Methallibure (I.C.I. 33, 828) und Thiourea.

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The work was supported by a University of Sydney Research Grant. I thank Mr.J. Collard, of the Veterinary Division of I.C.I.A.N.Z. Ltd., for supplies of Methallibure and Mrs.M. Weinstock for her technical assistance.     

Contributions to the cytology of Indian scorpions

Zusammenfassung Die Chromosomenzahl vonHeterometrus scaber ist 96. WirdPalamnaeus swammerdami mit Colchicin (0,2%) behandelt, so ziehen sich die Chromosomen in der Prämetaphase I zusammen.Buthus tamulus (aus Mysore) zeigt weitgehend variable Chromosomenzahl (20–28). Die Lage der Chromosomen in der Metaphase I und Anaphase I weist auf Monozentrie, Bizentrie und Holokinetie.     

Experimentelle Feststellung dualer Potentiale an intra-nicht-permutierenden Membranen

Summary It has been shown experimentally that two different potentials appear across an intra-nonpermutating membrane³ when two different solutions (e.g., solution I: 0.1n NaCl+0.0001n KCl; and, solution II: 0.1n KCl + 0.0001n NaCl) are separated by such a membrane, and when the pores of the intra-nonpermutating membrane are supplied with ions from either solution I or solution II (in this case: essentially with Na⁺ ions from solution I, or essentially with K⁺ ions from solution II). The theoretical background, and other considerations, for these experiments will be found in reference.     

Genotypic differences between the mouse adenovirus strains FL and K87

Summary Restriction endonuclease analysis was used to compare the genome of mouse adenovirus (MAd) strains FL and K87. Large differences were found between theKpn I,PaeR7,Pvu I,Sal I andSma I restriction profiles of the prototype strains. MAd-FI and MAd-K87 thus represent two distinct species of mouse adenovirus.This work was supported by grants from the Fonds pour la formation de chercheurs et l'aide à la recherche and the Natural Sciences and Engineering Research Council of Canada.     

Incommensurabilities in the work of Thomas Kuhn

I distinguish between two ways in which Kuhn employs the concept of incommensurability based on for whom it presents a problem. First, I argue that Kuhn’s early work focuses on the comparison and underdetermination problems scientists encounter during revolutionary periods (actors’ incommensurability) whilst his later work focuses on the translation and interpretation problems analysts face when they engage in the representation of science from earlier periods (analysts’ incommensurability). Secondly, I offer a new interpretation of actors’ incommensurability. I challenge Kuhn’s account of incommensurability which is based on the compartmentalisation of the problems of both underdetermination and non-additivity to revolutionary periods. Through employing a finitist perspective, I demonstrate that in principle these are also problems scientists face during normal science. I argue that the reason why in certain circumstances scientists have little difficulty in concurring over their judgements of scientific findings and claims while in others they disagree needs to be explained sociologically rather than by reference to underdetermination or non-additivity. Thirdly, I claim that disagreements between scientists should not be couched in terms of translation or linguistic problems (aspects of analysts’ incommensurability), but should be understood as arising out of scientists’ differing judgments about how to take scientific inquiry further.     

Chromosome breaking activity of A139 in human lymphocytes in vitro

Zusammenfassung 2,5-bis-(methoxyäthoxy)-3,6-bis-äthylenimino-p-benzochinon (Bayer A 139) induziert dosisabhängig Chromatidenaberrationen in menschlichen Lymphozyten in vitro. Die intrachromosomale Aberrationsverteilung ist nicht zufällig.

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I thank Mrs.R. Pieper for her careful technical assistance. I am also grateful to the firm Bayer, Leverkusen, for supplying the A 139.     

Legionella pneumophila down-regulates MHC class I expression of human monocytic host cells and thereby inhibits T cell activation

Legionella (L.) pneumophila, the causative agent of Legionnaires disease, is an intracellular pathogen of alveolar macrophages that resides in a compartment displaying features of endoplasmatic reticulum (ER). In this study, we show that intracellular multiplication of L. pneumophila results in a remarkable decrease in MHC class I expression by the infected monocytes. During intracellular multiplication, L. pneumophila absorbs ER-resident chaperons such as calnexin and BiP, molecules that are required for the correct formation of the MHC class I complex. Due to reduced MHC class I expression, stimulation of allogeneic blood mononuclear cells was severely inhibited by infected host cells but cytotoxicity of autologous natural killer cells against Legionella-infected monocytes was not enhanced. Thus, reduced expression of MHC class I in infected monocytes may resemble a new immune escape mechanism induced by L. pneumophila.Received 22 November 2004; received after revision 27 December 2004; accepted 5 January 2005     

Selectivity of alterations in skeletal fibers in chronic Chagas' disease of the mouse

Summary In mice chronically infected withTrypanosoma cruzi, the masseter muscle (rich in type II fibers) was devoid of inflammatory infiltrates and parasites. In contrast, other muscles, composed of type I and II fibers, showed a decrease of type I fibers, parasites and lesions, suggesting that inT. cruzi infection type I muscle fibers are selectively damaged.     

Ligand recognition by the I domain-containing integrins

Seven of the integrin α subunits described to date, α ₁ , α ₂ , α _L , α _X , α _d , α _M and α _E , contain a highly conserved I (or A) domain of approximately 200 amino acid residues inserted near the amino-terminus of the subunit. As the result of a variety of independent experimental approaches, a large body of data has recently accumulated that indicates that the I domains are independent, autonomously folding domains capable of directly binding ligands that play a necessary and important role in ligand binding by the intact integrins. Recent crystallographic studies have elucidated the structures of recombinant α _M and α _L I domains and also delineated a novel divalent cation-binding motif within the I domains (metal ion-dependent adhesion site, MIDAS) that appears to mediate the divalent cation binding of the I domains and the I domain-containing integrins to their ligands.     

The structure of human interferon-β: implications for activity

Interferons (IFNs) are potent extracellular protein mediators of host defence and homoeostasis. This article reviews the structure of human IFN-β (HuIFN-β), in particular in relation to its activity. The recently determined crystal structure of HuIFN-β provides a framework for understanding of the mechanism of differentiation of type I IFNs by their common receptor. Insights are generated by comparison with the structures of other type I IFNs and from the interpretation of existing mutagenesis data. The details of the observed carbohydrate structure, together with biochemical data, implicate the glycosylation of HuIFN-β, which is uncommon among type I IFNs, as an important factor in the solubility, stability and, consequently, activity of the protein. Finally, these structural implications are discussed in the context of the clinical use of HuIFN-β. Received 12 June 1998; received after revision 16 July 1998; accepted 16 July 1998     

The effect of sulfhydryl reagents on cation binding by membrane fragments

Zusammenfassung Nachweis an Lebermikrosomen der Ratte, dass Sulfhydryl Reagenzienp-Chloromercuribenzoat (pCMB) undp-Chloromercuribenzol Sulfonat (pCMBS) die Bindung von Magnesium und Calcium ungefähr um 20% vermindern.

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I wish to thank Dr.George L. Ellman for several of the sulfhydryl reagents and for discussions relating to the present study. I also wish to thank Mr.Thian Vui Mark Lee for his capable assistance during the course of this investigation.     

Kelletinin I and kelletinin A from the marine molluscBuccinulum corneum are inhibitors of eukaryotic DNA polymeraseα

Summary The inhibitory effect of esters of p-hydroxybenzoic acid (kelletinins I and A), extracted from the marine gastropodBuccinulum corneum, have been tested on eukaryotic and prokaryotic enzymes of DNA metabolism such as DNA polymerases and , DNA polymerase I, Exo III, pancreatic DNAse I, micrococcal DNAse andE. coli RNA polymerase. Kelletinin I and kelletinin A inhibit preferentially DNA polymerase. The inhibitory effect of kelletinin I involves the hydroxyl group of p-hydroxybenzoic acid.     

Evaporative resistance of pulmonary surfactant films

Summary Films of surfactant from the lungs of rabbits, tortoises (Testudo hermanni) and frogs (Rana pipiens) offer resistance to the evaporation of water.I wish to thank Mr G. Bryan for technical assistance.