Microinjection of synthetic protein kinase inhibitor into single barnacle muscle fibers before and after cyclic AMP

Single muscle fibers from the barnacle Balanus nubilus have been used as a preparation to see if a synthetic 20-residue PKI (5-24)-peptide is able to block or reverse the stimulatory response of the ouabain-insensitive Na efflux to injected cAMP. The results obtained show that this peptide behaves as a powerful inhibitor of the cAMP-mediated response and is also able to partially reverse the sustained stimulation of the Na efflux observed in ouabain-poisoned fibers following the injection of subunit A of cholera toxin.     

Rp-diastereomer of adenosine cyclic 3',5'-phosphorothioate as an antagonist of the stimulatory action of cyclic AMP on the ouabain-insensitive Na efflux in single barnacle muscle fibers

Single muscle fibers of the barnacle Balanus nubilus have been used as a preparation to test the possibility that the Rp-diastereomer of adenosine cyclic 3',5'-phosphorothioate, which is the first available analog of cAMP that acts as an antagonist of cAMP, may reduce the magnitude of cAMP-mediated stimulation of the resting ouabain-insensitive Na efflux. The results obtained show that this antagonist is, in fact, able to reduce stimulation of the Na efflux by injected cAMP in a dose-dependent manner.     

Tris as a blocking agent of the proton-sensitive component of the sodium efflux in barnacle muscle fibers

Zusammenfassung Studien über den Natriumtransport in den Muskeln vonBalanus sp. haben bewiesen, dassTris den protonempfindlichen Anteil der Natrium-Pumpe verlangsamt und dasTris hauptsächlich an der Aussenseite des Sarkolemms aktiv ist.

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Acknowledgments. This work was supported in part by grants from the Wisconsin Heart Association, the Medical School Research Committee, the Graduate School Research Committee and the Office of Naval Research. Our thanks are due to Mr.Geoffrey Chambers for technical assistance. E.Y.T. is a Postdoctoral Fellow of the Wisconsin Heart Association. B.G.D. is a Visiting Scientist of the American Heart Association.     

Na fluxes in human mononuclear leucocytes

Unidirectional 22Na fluxes were investigated in human peripheral mononuclear leucocytes. Ouabain inhibited about 60% of Na efflux and the addition of bumetanide further reduced Na efflux rate by about 45%, suggesting the presence of a transport pathway capable of extruding Na against its gradient. Prostaglandins E1 and E2 and exogenous cAMP were found to be potent inhibitors of the bumetanide-sensitive Na efflux without affecting the ouabain-sensitive or the ouabain and bumetanide resistant Na effluxes.     

(±)9, 10-dihydroxy-Δ 6a(10a)-tetrahydrocanabinol and (±)8, 9-dihydroxy-Δ 6a(10a)-tetrahydrocannabinol: 2 new cannabinoids fromCannabis sativa L.

Summary The structures of 2 new polyhydroxylated cannabinoids, (±)9, 10-dihydroxy- ^6a(10a)-tetrahydorcannabinol and (±)8, 9-dihydroxy- ^6a(10a)-tetrahydrocannabinol, obtained from a hexane extract of an IndianCannabis variant were determined by spectral means and correlation with cannabinol.Acknowledgments. Supported by contract No. HSM-42-70-109 from the National Institute on Drug Abuse and the Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi. The authors are grateful to Mrs Glenda Lewis (Research Institute) for running the gas chromatographic analyses and to Mr C. Versluis (Analytical Chemistry Laboratory, University Of Utrecht, The Netherlands) for recording an element list of both compounds.Cannabis Herbarium specimens are stored in the herbarium, Department of Pharmacology, School of Pharmacy, University of Mississippi, University, MS 38677, USA.     

Role of salivary glands in the maintenance of midgut amylase activity inPeriplaneta americana L.

Summary It was experimentally demonstrated, by the surgical removal of salivary glands and severence of salivary ducts, that most of the amylase in the gut ofPeriplaneta americana comes from the salivary glands.We wish to acknowledge Prof. H. Swarup (Jiwaji University, Gwalior, M.P.) for working facilities provided at School of Studies in Zoology, Vikram University, Ujjain, M.P., and Council of Scientific and Industrial Research, New Delhi, for fincancial support in the form of Junior Research Fellowship to one of us (O.P.A.)     

Fine structure of modiffied phtoreceptor cells in the pineal of the gobyClevelandia ios (Pisces: Gobiidae)

Summary Photoreceptor cells with a system of long, thi cytoplasmic processes (50–80 nm thick), which amy represent a modification of the outer segment saccules, are described in the pineal of the goby,Clevelandia ios.The author wishes to thank Mr Larry Allen, who helped collect the specmens, and Mr Kyle Kikuchi, who was instrucmental in the preliminary studies.Partial support by Biomedical Research Support Grant (NIH) No. 447-12-000 from the Stritch School of Medicine is gratefully acknowledged.     

Phosphatase activity in testis and prostate of rats treated with embelin andVinca rosea extract

Summary Daily administration ofVinca rosea Linn. extract orally and embelin s.c. to male albino rats caused significant rise in levels of acid and alkaline phosphatases of testis and prostate indicating altered metabolic function.We acknowledge the financial support by Indian Council of Medical Research and Council of Scientific and Industrial Research, New Delhi. Thanks are due to Dr J. Bahadur, School of Studies in Zoology, Jiwaji University, Gwalior for providing laboratory facilities.     

Establishment of a cell line (XTC-2) from the South African clawed toad,Xenopus laevis

Résumé On décrit une méthode pour l'établissement d'une culture de cellules du crapaud a griffes sudafricain,Xenopus laevis, afin de l'infecter avec des arbovirus. Les cellules (XTC-2) ont subi une culture continue pendant 3 ans. Elles ont un nombre diploïde de chromosomes. Elles furent cultivées aux températures de 22°C et de 28°C dans un milieu de culture dilué de NCTC 109 avec 10% de sérum de veau foetal.

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We thank ProfessorD. S. Bertram, Director of the Department of Entomology at the School, for his continued interest; Mr.A. O. Langi for technical assistance and Dr.L. Hamilton, Middlesex Hospital Medical School, London, for supplying theXenopus tadpoles. We are especially grateful to the Wellcome Research Laboratories, Beckenham, for supplying medium NCTC 109, and to Mr.D. J. Richmond of the Laboratories for responding to our request for medium promptly and willingly. The work is supported in part by a grant from the Medical Research Council of Great Britain.     

Purification from human plasma of endogenous sodium transport inhibitor(s)

Na+,K+-ATPase inhibitors extracted from plasma of healthy human subjects displaced 3H-ouabain binding to human erythrocytes and inhibited the Na+ efflux catalyzed by the Na+,K+-pump and unexpectedly the Na+,K+-cotransport system without alteration of the Na+,Na+-exchange or the Na+ passive permeability. This suggests the presence in healthy human plasma of endogenous factors with ouabain-like and furosemide-like activities.     

Evidence of abnormalities in net sodium and potassium fluxes in erythrocytes of patients with essential hypertension]

A new and simple laboratory test for measuring net Na+ and K+ fluxes in Na+-loaded/K+-depleted human erythrocytes was developed and applied to hypertension. Moderate essential hypertension was characterized by a constant increase in net K+ influx; more severe cases showed a drop in net Na+ efflux. Na+ and K+ erythrocyte fluxes were found to be normal in hypertension of renal origin.     

Immunohistochemical localization of pancreatic polypeptide (PP) in the brain of the larval instar of the hoverfly,Eristalis aenus (Diptera)

Summary 2 pancreatic polypeptide (PP) immunoreactive cells were observed in each half of the protocerebrum of the last (5th), larval instar of the hoverfly,Eristalis aenus. No PP immunoreactive nerve fibers could be detected in the brain.Support by a grant from the Swedish Medical Research Council (project No. 12X-102) and by a Swedish Institute scholarship.     

Electrogenic hyperpolarization in canine cardiac Purkinje fibres exposed to calcium ionophores

Summary The Ca ionophores markedly enhance the increase of intracellular Ca occurring during Na-free perfusion and the hyperpolarization observed upon Na readmission may be due to rapid restoration of intracellular Na and resultant stimulation of both electrogenic sodium and calcium efflux.This work was supported by a grant-in-aid and a Senior Investigatorship from the New York Heart Association.     

Cannabiripsol: A novelCannabis constituent

Summary Cannabiripsol [(–)(6aR, 9S, 10S, 10aR)9,10-dihydroxy-hexahydrocannabinol] (1), a new cannabinoid was isolated from a South African Cannabis variant. The structure was determined by spectral means and by synthesis.Acknowledgments. This work was supported by contract HSM-42-70-103 from the National Institute on Drug Abuse and by the Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS 38677. —Cannabis Herbarium specimens are stored in the Herbarium, Department of Pharmacognosy, School of Pharmacy, University of Mississippi.To whom inquiries should be addressed.     

Inactivation of yeast glucose-6-P dehydrogenase by aspirin

Summary Glucose-6-P dehydrogenase is irreversibly inactivated by treatment with Na salts of aspirin. Kinetic data show that 1 molecule of aspirin reacts with each active unit when the enzyme is inactivated. The rate of inactivation is enhanced with increasing pH but is reduced in the presence of glucose-6-P or NADP⁺. Na salicylate fails to inactivate the enzyme.This work was supported by grant RR-8006 from the General Research Branch, Division of Research Resources, NIH (USA).     

Forecasting the economic recession in the U.K. 1979-1982: A comparison of model-based ex ante Forecasts

This paper compares the forecasts of recession and recovery made by five non-government U.K. teams modelling the economy (Cambridge Econometrics, the London Business School, the National Institute of Economic and Social Research, the Cambridge Economic Policy Group and the Liverpool Research Group). The paper concentrates on annual ex ante projections as published over the period 1978-1982, i.e. forecasts made, before the event, of the onset, length, depth and character of the economic recession in the U.K. which began in 1979. The comparison is in terms of year by year changes in production, unemployment, prices and other variables. It concludes that no group was systematically better or worse than other groups (confirming U.S. experience) and that the groups tended to perform better in their chosen areas of specialization, e.g. medium-term groups did better at forecasting the medium-term outcome.     

An arachidonic acid-specific lipoxygenase from the gorgonian coralPseudoplexaura porosa

Summary A novel lipoxygenase was partially purified from the gorgonian coralPseudoplexaura porosa and was found to be specific for arachidonic acid. This soluble enzyme catalyzed the formation of 15-hydroperoxy-eicosatetraenoic acid (15-HPETE) from arachidonic acid.This investigation was supported by PHS grant No. CA32395 awarded by the National Cancer Institute and by PHS Research Carreer Development Award No. ES00120 to MDC awarded by the National Institute of Environmental Health Sciences, DHHS. The authors acknowledge Ms M. A. Russell and Dr D. G. Anderson of the University of Miami for assistance in the collection of gorgonian corals. Preliminary work was conducted at the University of Miami School of Marine and Atmospheric Science. This is journal series No. 3638 from the Florida Agricultural Experiment Station.     

Acetaldehyde oxidation inDrosophila null-mutants for alcohol dehydrogenase

Summary Aldehyde dehydrogenase (ALDH) activity is demonstrated in four strains ofD. melanogaster lacking active alcohol dehydrogenase (ADH-null mutants). In the four strains, ALDH activities are similar to those found in a wild strain. It is concluded that ADH-null flies are able to detoxify acetaldehyde. This finding is discussed in relation with the dual function of ADH proposed recently.This work was supported by a grant from the Medical Research Council of Canada (MRC 6920) to Dr F. Garcin.     

Isolation of a neurosecretory substance which stimulates RNA synthesis in regenerating planarians

Summary An approach to the isolation of neurosecretory material from planarians is described. This material stimulated RNA synthesis, in a dose-dependent response, in regeneratingDugesia tigrina. The data support the concept that neurosecretion plays a key role in the process of regeneration in planarians.Supported by funds from the National Research Council of Canada.     

Spatiotemporal asymmetric auxin distribution: a means to coordinate plant development

The plant hormone auxin plays crucial roles in regulating plant growth development, including embryo and root patterning, organ formation, vascular tissue differentiation and growth responses to environmental stimuli. Asymmetric auxin distribution patterns have been observed within tissues, and these so-called auxin gradients change dynamically during different developmental processes. Most auxin is synthesized in the shoot and distributed directionally throughout the plant. This polar auxin transport is mediated by auxin influx and efflux facilitators, whose subcellular polar localizations guide the direction of auxin flow. The polar localization of PIN auxin efflux carriers changes in response to developmental and external cues in order to channel auxin flow in a regulated manner for organized growth. Auxin itself modulates the expression and subcellular localization of PIN proteins, contributing to a complex pattern of feedback regulation. Here we review the available information mainly from studies of a model plant, Arabidopsis thaliana, on the generation of auxin gradients, the regulation of polar auxin transport and further downstream cellular events. Received 10 March 2006; received after revision 26 June 2006; accepted 9 August 2006