Influence of PGA1 on cartilage growth

Summary Using the Fell technique of organ culture of cartilage in a chemically defined medium, it has been shown that prostaglandin A₁ at a concentration of 25 g/ml caused chondrocyte death in chick embryonic limb rudiments. An equimolar concentration of PGE₂ was not toxic to the cells.Acknowledgments. We are grateful for the support of C. J. K. by the Medical Research Council and of D. L. G. by the Arthritis and Rheumatism Council for Research. Our thanks are due to Dame Honor Fell, F. R. S. for invaluable advice and guidance, to Dr J. Pike (Upjohn Co.) for supplies of prostaglandin A₁, and to Dr Sylvia Fitton-Jackson for the gift of culture medium.     

Reduction of aflatoxin B1 with zinc borohydride: An efficient preparation of aflatoxicol

Summary A simple and mild reduction of aflatoxin B₁, involving treatment of aflatoxin B₁ with ethereal zinc borohydride to give 57–65% yield of diastereomeric aflatoxicols, is described.This work was supported by the College of Agricultural and Life Sciences, the University of Wisconsin, Madison, and by Public Health Service Research, grant No. CA 15064, from the National Cancer Institute, and by funds from contributions of food industries to the Food Research Institute. We are grateful to Professor Dennis Hsieh for a gift of natural aflatoxicol, to Mr William Harder for technical assistance throughout this investigation, and to Mr Gary Girdaukas for taking mass spectra.     

Metabolism of aflatoxins B1 and G1 byAspergillus parasiticus

Résumé Un examen préliminaire fait avec une préparation d'Aspergillus parasiticus est rendu évidente la conversion de l'aflatoxine B en G. Il est probable que l'aflatoxines B₁ est le précurseur biogénétique d'autres aflatoxines produite par le champignon.

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K. K. M. is grateful to the Council of Scientific and Industrial Research, New Delhi, India, for the award of a Senior Research Fellowship.     

Effects of the optical isomers of 2-amino-3-fluoro-1-phenylpropane (monofluoroamphetamine) hydrochloride on uptake and release of dopamine in rat striatum in vitro

Summary The (+)- and (–)-isomers of the monofluorinated amphetamine 2-amino-3-fluoro-1-phenylpropane were prepared and compared for their ability to stimulate release and to inhibit reuptake of radiolabelled dopamine from rat striatal tissue in vitro. The (+)-isomer was much stronger than the (–)-isomer in both cases.Financial support for this project was supplied by the Medical Research Council of Canada, the Alberta Mental Health Research Fund and the Special Services and Research Committee, University of Alberta Hospital.Acknowledgments. Skilled technical assistance was provided by Ms L. Hiob. The authors also wish to thank Dr W.G. Dewhurst, Department of Psychiatry, and Dr D.F. LeGatt, for their advice and comments.     

Beta1-adrenoceptor mediated salivary gland enlargement in the rat

Summary In the rat, prolonged activation of ₁-adrenoceptors causes a gain in salivary gland weight, whereas prolonged blockade of these receptors causes a reduction in weight.This work was supported by grants to J.E. from the Medical Faculty in Lund and the Swedish Medical Research Council (05927).     

Inhibition of neurotensin (NT)-induced glucagon release by [D-Trp11]-NT1

Summary A synthetic analog of neurotensin (NT), [D-Trp¹¹]-NT, antagonized NT-induced hyperglucagonemia and hyperglycemia, and also NT-induced glucagon release from pancreatic islets in rats.This work was supported in part by a grant from the Imanaga Medical Research Foundation, Nagoya, Japan. Address for reprint requests: M.U., Department of Surgery, National Nagoya Railway Hospital, Taiko 1-chome, Nakamura-ku, Nagoya 453, Japan.     

Ar1-5 and Ar2-6 aryl participation in ionic and free radical processes

Zusammenfassung Die Beteiligung von Arylgruppen in Solvolysen von 4-Aryl-1-butylhalogeniden und Arylsulfonaten sowie in Reaktionen von freien 4-Aryl-1-butyl-radikalen wird diskutiert. Bei geeignet methoxylierten oder hydroxy-lierten 4-Aryl-1-butylverbindungen kann die Formolyse entweder mit Ar₁-5-oder Ar₁-6-Arylbeteiligung verlaufen. Dies führt zur Bildung von Tetralin. Da bei Ar₁-5-Beteiligung ein Spirocarboniumion entsteht, in welchem entweder C oder C der ursprünglichen Butylseitenkette wandern kann, ist es möglich, dass ein anderes Tetralin geformt wird als auf dem direkteren Ar₂-6-Weg. Als Beispiel dient die Formolysenreaktion von 4-p-Anisyl-4-methyl-1-pentylbrombenzolsulfonat.

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Research supported by the Office of Naval Research. — Research sponsored by the Office of Ordnance Research, U. S. Army.     

Covalent binding of aflatoxin B1 to liver DNA in rats pretreated with ethanol

Summary Male Fischer F-344 rats were given ethanol in the drinking water and/or by single oral administration. Following this, the animals received p.o. 100 ng/kg of the hepatocarcinogen [³H]aflatoxin B₁ (AFB₁). 24 h later, the level of DNA-bound AFB₁ was determined in the liver and was found not to be affected by any type of ethanol pretreatment. A cocarcinogenic effect of ethanol in the liver is therefore unlikely to be due to an effect on the metabolic activation and inactivation processes governing the formation of DNA-binding AFB₁ metabolites.To whom correspondence should be addressed.Acknowledgment. We thank the European Science Foundation for the Toxicology Research Fellowship awarded to M.M.     

Effect of sodium butyrate in combination with prostaglandin E1 and inhibitors of cyclic nucleotide phosphodiesterase on human amelanotic melanoma cells in culture

Summary Sodium butyrate and cyclic AMP-stimulating agents (prostaglandin E₁, papaverine, theophylline, and RO20-1724) caused reductions in the cell number (primarily due to reduction in cell division) when added individually to human melanoma cells in culture. However, the combination of sodium butyrate with one of the cyclic AMP-stimulating agents produced a marked reduction in cell number (primarily due to cell death).Supported in part by BRSG grant RR-05357 awarded by Biomedical Research Support Grant Program, Division of Research Resources, National Institutes of Health. We thank Marianne Gaschler for her technical help.     

Fungistatic action of aflatoxin B1

Résumé La croissance des plusieurs espèces d'Aspergillus et dePenicillium dans un milieu modifié de Czapek a été inhibitée par l'aflatoxin B₁. Cet arrêt de croissance pourrait être annulé en substituant au nitrate de sodium un extrait de levure comme source d'azote.

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This is a laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, U.S. Department of Agriculture.     

The structures of minor congeners of detoxin complex,the selective antagonist of blasticidin S1

Summary The structures of the minor congeners of detoxin complex, viz., detoxins E₁, C₁, C₂, C₃, B₁, B₃ and A₁ have been established on the basis of spectral and degradative evidence.Acknowledgment. This work was supported by a Grant-in-Aid for Special Project Research (510208) from the Ministry of Education, Science and Culture, Japan. We are grateful to Kaken Chemical Co. Ltd for the supply of the detoxin complex. This is Part V of studies of Detoxin Complex, the Selective Antagonists of Blasticidin S'. For Part IV, see Ogita et al.⁸.     

An age factor affecting variance of a behavioural character in F1 hybrids between inbred lines of the house mouse

Zusammenfassung Eines der Nestbauverhaltenselemente bei Mäusen (Beknappern von Papierstreifen) wurde bei 2 Inzuchtstämmen und deren F₁- und F₂ Hybriden verglichen. F₁-Tiere zeigten im Vergleich zu den Eltern eine grössere Variationsbreite des Verhaltenselementes. Ein grosser und besonders signifikanter Teil dieser Variabilität war einer altersabhängigen Verschiebung zuzuschreiben. Diese kommt wahrscheinlich nicht infolge eines Lernprozesses zustande, sondern durch Änderungen der genetisch-regulierenden Mechanismen (wie. z.B. Dominanz und Epistasie).

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Research supported by a grant from the Netherlands Organization for the Advancement of Pure Research (Z.W.O.). The authors are grateful to MissG. J. Blokzijl for help in making the German summary.     

The effect of pentagastrin on the A1-cells of the pancreatic islets in guinea-pigs

Zusammenfassung Meerschweinchen wurden für 5 Tage mit Pentagastrin injiziert und die Kerngrössen in den Pankreas-Inseln mit Karyometrie bestimmt. Die Kerne der A₁-Zellen nahmen in den behandelten Tieren am Anfang ab und schienen kleiner als in den Kontrollen. In den A₂-und B-Zellen wurden keine Veränderungen nach Pentagastrin notiert. Die Resultate stützen die Auffassung, dass Gastrin in den A₁-Zellen produziert wird.

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The work was supported by grants from the Swedish Medical Research Council No. B70-2297-03. The pentagastrin (Peptavlon) was kindly supplied by Imperial Chemical Industries (ICI).     

Inheritance and expression ofEsterase-1 allozymes inPeromyscus leucopus

Summary We analyzed inheritance of 5Es-1 alleles inP. leucopus and found them to be co-dominant and segregating from a single autosomal locus, thereby verifying assumptions of Mendelian inheritance imfield data. We also described an allele that is silent in hemolysate, but is active in liver extract.Acknowledgment. Laboratory analysis was partially supported by a grant-in-aid (No. 0171-02-240-76) to Kaufman from the Research Foundation of State University of New York.     

Elevated kidney glucosyltransferase activity in genetic prediabetic mice

Summary Glucosyltransferase activity in the renal cortex of genetic diabetic KK mice was significantly increased at 40 days of age when compared to that of Swiss albino and F₁ hybrid mice. This increase in enzyme activity in the absence of glucose intolerance can be regarded as an earlier genetic marker for the diagnosis of diabetic microangiopathy.Acknowledgments. This research was supported in part by the General Research Support Grant No. RR-05398 from the General Research Support Branch, Division of Research Resources, National Institutes of Health, National Institutes of Health Training Grant No. 5-T01-AM-05617-06, Hope for Diabetics Foundation, Inc., and Pfizer Research Laboratories. Dr.R. A. Camerini-Davalos was a Career Scientist of the Health Research Council of the City of New York, and Drs.A. S. Reddi andC.A. Velasco were N. I. H. Trainees in Diabetes Mellitus during part of this study.     

The inhibiting actions on poliovirus multiplication of 1-alkyl-2-(α-methoxybenzyl)benzimidazoles

Zusammenfassung 1-Alkyl-2-(-methoxybenzyl)-benzimidazole hemmt die Vermehrung des Poliovirus der Arten 1, 2 und 3, wobei das 1-Propyl-Derivat die grösste Wirkung hat.

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The research is supported by the National Fund for Research into Poliomyelitis and other Crippling Diseases.     

Action of ACTH,cAMP and cytochalasin B on steroid production by Y-1 mouse adrenal tumor cells in culture

Summary Continued incubation of Y-1 mouse adrenal tumor cells with adrenocorticotrophic hormone (ACTH) or with dibutyryl-3,5-cyclic adenosine monophosphate (dbcAMP) resulted in an initial increase and a subsequent decrease in steroidogenesis. ACTH-or dbcAMP-stimulated steroidogenesis was inhibited by cytochalasin B (CB) to approximately the same extent during the entire period of incubation; CB inhibition of the ACTH response was reversible.Supported in part by NTSU Faculty Research grant No. 34711, and NIA No. AG01055-02A1.Acknowledgment is made for the assistance of L. Hershberger, J. Youngblood and V. Dang; K. Mrotek, K. Johansson and M. Donahue were editors.     

L1CAM malfunction in the nervous system and human carcinomas

Research over the last 25 years on the cell adhesion molecule L1 has revealed its pivotal role in nervous system function. Mutations of the human L1CAM gene have been shown to cause neurodevelopmental disorders such as X-linked hydrocephalus, spastic paraplegia and mental retardation. Impaired L1 function has been also implicated in the aetiology of fetal alcohol spectrum disorders, defective enteric nervous system development and malformations of the renal system. Importantly, aberrant expression of L1 has emerged as a critical factor in the development of human carcinomas, where it enhances cell proliferation, motility and chemoresistance. This discovery promoted collaborative work between tumour biologists and neurobiologists, which has led to a substantial expansion of the basic knowledge about L1 function and regulation. Here we provide an overview of the pathological conditions caused by L1 malfunction. We further discuss how the available data on gene regulation, molecular interactions and posttranslational processing of L1 may contribute to a better understanding of associated neurological and cancerous diseases.     

Cholinergic properties of 1-methyl and 2-methylpentyltrimethylammonium salts

Résumé Étude des propriétés cholinergiques des iodures du méthyl-1 et du méthyl-2-pentyltriméthylammonium. Dans leur comportement agonistique, ces sels offrent des variations parallèles à celles de dérivés méthyles de l'acétylcholine. Le cation pentyltriméthylammonium est donc capable de s'associer aux récepteurs cholinergiques tels que l'acétylcholine.

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This investigation was supported by Grant No. MA-3359 to M.H. from the Medical Research Council of Canada.     

Survival and endogenous spleen colonies of irradiated mice after skin wounding and hydroxyurea treatment

Summary Wound trauma-induced survival from radiation may be related to increased mitosis in hematopoietic cells. This is supported by the cell cycle-dependent drug hydroxyurea, which 1. blocked survival of wounded mice injected 2 or 3 days after 900 rad and 2. reduced the number of endogenous CFU-s in wounded mice injected shortly before 700 rad.Supported by the Armed Forces Radiobiology Research Institute, Defense Nuclear Agency, under Research Work Unit MJ00018. Views presented in this paper are those of the authors; no endorsement by the Defense Nuclear Agency has been given or should be inferred.Research was conducted according to the principles enunciated in the Guide for the Care and Use of Laboratory Animals prepared by the Institute of Laboratory Research, National Research Council.