Effect of seasonal variations and cold acclimation on serum transaminase activity of common Indian frogRana tigrina

Summary A definite seasonal change is observed in 2 transaminases, SGOT and SGPT ofR. tigrina. Cold acclimation significantly depresses transaminase activity of serum.Acknowledgments. Thanks are due to Dr M.M. Goil and Dr R. K. Sharma for their invaluable help in various ways. Dr K. Singh would also like to thank S.C.S.T., U.P., for the financial assistance.     

The tension/length relationship of an insect (Calliphora erythrocephala) supercontracting muscle

Summary The tension/length curves of an insect supercontracting striated muscle are described. Both vertebrate and invertebrate smooth (non-striated) muscles show a close similarity to these curves. Thus, although insects possess only striated muscle, some of these muscles can perform the function of smooth muscle of other animals.I would like to thank Dr.M. P. Osborne for supervizing this work which was supported by an S. R. C. studentship.     

Evolutionary implications of ascorbic acid production in the Australian lungfish

Summary It is shown that the Australian lungfish (Neoceratodus forsteri) synthesizes ascorbic acid in its kidney, suggesting that ascorbic acid synthesis started before the origin of the tetrapods.Acknowledgments. We would like to thank Dr G.C. Grigg, University of Sydney, Mr R. B. Humphries, Dr P.A. Janssens and Dr C.H. Tyndale-Biscoe, Australian National University, and Dr. M. Griffiths and J.C. MacIlroy C.S.I.R.O., Division of Wildlife Research for supplying the tissue.     

Occurence of diploid drones in a neotropical bumblebee

Zusammenfassung Mutter-Sohn-Kreuzung bei der südamerikanischen HummelBombus atratus Franklin ergab diploide Männchen mit normalen Arbeiterinnen im Verhältnis von 3 zu 1. Tur Interpretation des genetischen Mechanismus wurden 2 geschlechtsgebundene Loci angenommen, als bisher angenommen wurde, was für einen älteren Mechanismus bei Apiden spricht.

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This study was made possible by a grant of the State of São Paulo Research Foundation (FAPESP).

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Acknowledgment. I would like to thank Dr.W. E. Kerr, Dr.R. Zucchi and Dr.S. F. Sakagami for their excellent assistance during the course of this investigation as well during the translation. I also would like to thank Dr.R. H. Crozier for his suggestions and comments and I extend my thankfulness to professorsJ. Chaud Netto andZ. Silveira.     

Hybridization between Robertsonian karyotypic races of the common shrewSorex araneus

Summary British common shrews of the Aberdeen, Oxford and Hermitage Robertsonian karyotypic races were hybridized successfully in captivity. Hybrids, both simple Robertsonian heterozygotes and double Robertsonian heterozygotes with monobrachial homology, have been identified in an area of contact between the Oxford and Hermitage races. The relative fertility of these two types of hybrid is considered.I thank Dr. C. E. Ford F. R. S., Prof. F. W. Robertson and Dr A. E. Douglas for reading earlier drafts of this paper, Prof. F. W. Robertson, Dr J. R. K. Savage and Dr J. R. Clarke for laboratory facilities, Mrs J. E. Evans for technical assistance and S.E.R.C. for financial support.     

Preservation ofBordetella pertussis

Summary Bordetella pertussis has been shown to remain viable for a period of 13 years on freeze-drying. The revived cultures had unaltered antigenic composition and biological activity.Thanks are due to Dr M. Balasubrahmanyan for his guidance and Dr M.S. Zakharova, Gamaleya Institute of Microbiology and Epidemiology, Moscow, USSR for supplyingB. pertussis factor sera. We thank Mr Ram Jas for his technical assistance.     

Isolation and partial characterization of ovine lactoferrin

Summary Ovine lactoferrin was isolated by ammonium sulfate precipitation and ion exchange chromatography. Comparative analyses were performed with the bovine protein. Differences in the amino acid compositions and the tertiary structure of the proteins were observed.Acknowledgments. We would like to thank Dr M. Casey for his interest in this work, Dr P. Lavanchy for performing the amino acid analyses and M.F. Baumann for providing us with ewe milk.     

Epidermal sensitivity to hypoxia in the lugworm

Summary Physiological and anatomical data support the idea that in the caudal epidermis of the lugworm,Arenicola marina (L.), there are chemoreceptors detecting variations of oxygen partial pressure in the ambient water.This research was partly supported by a C.N.R.S. grant, AI No. 582 085. We thank Dr P. Dejours and Dr J. Taxi for helpful comments and discussion, Mrs S. Dejours for editing the English of this paper, M.F. Baucher, A. Dorme, F. Kleinbauer, the staff of the Station Biologique de Roscoff and the Service de Microscopie Electronique, C.N.R.S., boulevard Raspail, Paris, for technical assistance.     

3-Methyl-2-hexanone from the triatomine bugDipetalogaster maximus (Uhler) (Heteroptera; Reduviidae)

Summary The occurrence of 3-methyl-2-hexanone as a major component of the secretion and possible alarm substance from the metasternal scent glands in the triatomine bugDipetalogaster maximus is reported.The authors are indebted to Mr B.O.C. Gardiner of the Zoology Department, Cambridge, for a supply of livingDipetalogaster. They would like also to thank Dr D.E. Games for the provision of mass spectral facilities under support from the S.E.R.C.     

A new simple temperature-controlled membrane oxygenator for the perfusion of isolated rat livers

Summary A new temperature-controlled membrane oxygenator for perfusing isolated rat livers was assembled using a combination of heat-exchangeable rubber tubing and silicon rubber tubing. The apparatus supplied enough oxygen to satisfy the requirements of hemoglobin-free perfused livers.Acknowledgment. One of the authors (MO) would like to thank to Prof. Dr R. Scholz, Institut für Physiologische Chemie der Universität München, for his kind permission to observe his perfusion experiments and also for his valuable discussion.     

Effect of cyproterone acetate on the testis and epididymis of the lizard,Psammophilus dorsalis (Gray)

Summary The effect of cyproterone acetate (CPA) on the testis and epididymis of the lizard,Psammophilus dorsalis has been studied. Treatment with CPA affects spermatogenesis and steroid metabolism in the testis. It also causes regression of the epididymis and a decrease in steroidogenic enzyme activity.Acknowledgments. We wish to thank Prof. M.R. Rajasekarasetty for his encouragement, Dr K.V. Rao, Nagpur, for a generous gift of cyproterone acetate, Dr V.B. Nadkarni, Dharwar, for permitting the use of his cryostat, Sri B.M. Sekharappa for his technical assistance and UGC, New Delhi for their financial help to one of us (GRS).     

Photoreceptor properties of an ectopic eye in the fleshfly,Sarcophaga bullata

Summary Ectopic eyes were produced on the fleshfly,Sarcophaga bullata by transplantation of imaginal eye discs. Electrophysiological and histological observations of these supernumerary eyes indicate the absence of synaptic connections between retinular cells and higher order neurons.Supported by an University of New Brunswick research grant to P.S. and NSF grant BNS-76-11921 and NIH grant 1-R01-EY-02487-01A1 to W.S.S.We would like to thank Dr I.A. Meinertzhagen for suggestions and Mary Johnson for technical assistance.     

What determines the population size of the intracellular algal symbionts in the digestive cells of green hydra?

Summary The ratios of algal volume to amount of host protein in 5 strains of green hydra were found to be closely similar. However, the components of algal volume varied in the 5 strains, suggesting differences in interactions between animal and algal growth rates.Acknowledgements. This work was supported by an N.E.R.C. postgraduate research grant. I would like to thank Professor D.C. Smith, F.R.S., for his invaluable help in drafting this paper.     

Effect of propylthiouracil on intestinal tumor formation by azoxymethane in rats

Summary Treatment with propylthiouracil (PTU) resulted in a significant decrease in azoxymethane-induced intestinal tumors, total concentration of fecal bile acid as well as the fecal neutral steroids, cholesterol and coprostanol. Thus, a hypothyroid state induced by PTU treatment may affect intestinal carcinogenesis in this animal model by lowering the concentration of fecal bile acids and neutral steroids.We would like to acknowledge the excellent technical assistance of Dale Miller, Kenneth Kohn, Mathew McGee and Michael McLaughlin. We also wish to thank Dr M. S. Pak for the histological work, and Ms Mary Acree and Ms Kathleen Smith for the excellent secretarial assistance. Supported by the Maltida R. Wilson Fund.     

Effect of acrylonitrile on trehalase,phosphorylase and acetylcholinesterase activities inTribolium castaneum Herbst andTrogoderma granarium Everts

Summary Acrylonitrile inhibited trehalase and phosphorylases in larvae and adults ofTribolium castaneum. InTrogoderma granarium larvae phosphorylases alone were inhibited. Acetylcholinesterase was not affected.Acknowledgments. We thank Dr R. Radhakrishnamurthy for his suggestions.     

Precocene-induced metamorphosis in the desert locustSchistocerca gregaria

Summary 50–100% of the 2nd, 3rd and 4th instar nymphs ofSchistocerca gregaria exposed to precocene 2 by contact method metamorphosed precociously from the instar treated. The corpora allata of the precocious adults were degenerate. Topical application of a juvenile hormone analogue (ZR-512) induced in the precocious adults the colouration characteristic of sexually mature adults.This research was supported by the N.S.E.R.C. grant No.A4669.We thank Dr G. B. Staal, Zoecon Corporation, Palo Alto, California, for the generous gift of precocene 2 and ZR-512, M. Hota for rearing the insects, R. G. Long, for the photographs, and Jann Aitken for technical assistance.     

A new synthesis ofβ-fluoroaspartic acid

Summary -Fluoroaspartic acid, a new amino acid, was synthesized by a diazotization of diaminosuccinic acid in liquid hydrogen fluoride.Synthesis of Amino Acids and Related Compounds, part 21.—Part 20: Y. Ozaki, S. Maeda, M. Miyoshi and K. Matsumoto, Synthesis, 216 (1979).We would like to acknowledge Dr I. Chibata for his encouragement in this work.     

The in vitro characterization of the inhibition of mouse brain protein kinase-C by retinoids and their receptors

Summary The mechanism of the in vitro inhibition of Ca²⁺-, phosphatidylserine-dependent protein kinase C (PK-C)² by the purifiedholo (ligand-saturated) forms of cellular retinol-binding protein (cRBP) and cellular retinoic acid-binding protein (cRABP) was studied. We report here that i) the PK-C-inhibitory action ofholo-cRBP andholo-cRABP is due to their respective ligands, all-trans-retinol and all-trans-retinoic acid; ii) the reduced phosphorylation of theholo-retinoid-binding proteins and brain cytosolic proteins is not the result of a retinoid-induced soluble phosphatase or protease activity; iii) retinoids reduce PK-C affinity for calcium and phosphatidylserine in vitro; and iv) the structure-function activity of the retinoids and the specific interaction of these effect of retinoids on plasma membrane-associated PK-C activity pays a significant role in defining the early epigenetic aspects of PK-C-dependent tumor promotion and may be a physiological mechanism by which retinoids induce terminal differentiation in cell types that do not express soluble retinoid-binding proteins.We would like to thank Dr L.M. De Luca (NIH, USA) for his contribution of retinylphosphate, Dr H.N. Bhagavan (Hoffmann-La Roche) for his contribution of the arotinoids, and Merrill-Dow Corp. for their contribution of difluoromethylornithine. This work was supported by NIH Grants CA-34968, CA-07175, CA-22484, and CA-09020.     

Revised structures for iselin and iliensin and the identity of the former with archangelin

Summary Structures of iselin and iliensin have been revised. The structure (Ib) is secured for iselin by a direct comparison (m.p., UV, IR, PMR) with archangelin. The synthesis of iliensin (IIb) has been effected through the condensation of xanthotoxol (II, R=OH) and -cyclolavandulyl bromide (III). The synthetic product has been shown to be identical with natural iliensin.We thank Dr S.Z. Qasim and Dr M.S. Chadha for the spectral data and C.S.I.R. for a research fellowship to J.V.     

Effect of substrates on the mechanical performance of rhesus monkey papillary muscle

Summary This study examines the effect of different substrates on mechanical performance of excised papillary muscles from rhesus monkeys which had been divided into a control group and an experimental group fed a high fat diet for 5 months prior to sacrifice. The results show that performance is affected by available substrate for both groups. The performance of the experimental group was depressed relative to control with the short chain fatty acid, butyrate (C4), producing a monotonically decreasing force-frequency response. Relative to other mammals, isolated rhesus papillary muscles exhibited a protracted treppe which was sensitive to -adrenergic blockade with propranolol.Acknowledgments. I would like to thank Dr R.M. Larson, Dr R.L. McCann and Dr O.F. Hagan for making available the papillary muscles used in this study. Support for this work was provided in part by a grant from the Walker P. Inman Fund and grants from the NIH HL 17391 and HL 15448.