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1.
Summary Based on observations and on analogical deductions from the organization of the cerebellum, a hypothesis of a passive process of thinking is described. According to it, we try to program the cerebrum for the handling of an idea, regarding its solution we are, however, exposed passively to the brain.  相似文献   

2.
Summary A new sesquiterpene alcohol, 12-hydroxy-E--bisabolene, is reported from an undescribed Caribbean sea whip of the genusPseudopterogorgia. The structure of this new alcohol was established based upon spectral analyses and through chemical interconversions.Acknowledgment. This research was supported by NOAA, Office of Sea Grant, Department of Commerce, under grant NA80AA-D-00120, and in part by the California State Resources Agency, project R/MP-22. The U.S. Government is authorized to reproduce and distribute reprints. We wish to acknowledge the mass spectral support provided by the Bioorganic Biomedical Mass Spectrometry Resource Center, University of California, San Francisco (A.L. Burlingame, Director) which is supported through NIH grant RR00719.  相似文献   

3.
During the nineteenth century French chemistry was marked by an outstanding number of Alsatian chemists whose scientific contributions cannot be ignored. Especially following the Franco-Prussian War, their regional origin was given a particular importance as a means of affirming their singularity on the French scientific scene. However, some questions may be raised: can we distinguish the Alsatians from other French chemists before 1870? Were they a homogeneous group sharing a common origin? The aim of this article therefore, is, to show that by their theoretical options within chemistry, their personal and professional relationships, as well as by their participation in various common initiatives, they organized themselves both formally and informally within the Parisian scientific community. Amongst these forms of organization the research school of Charles Adolphe Wurtz (1817-84) emerges as the nucleus of what we may envisage as a network of Alsatian chemists working in Paris, in the second half of the nineteenth century.  相似文献   

4.
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.  相似文献   

5.
Summary In the rabbit isolated aorta, hymenin (10–6 M) a novel marine alkaloid, caused a parallel rightward shift of the dose-response curve for norepinephrine without affecting that for histamine or KCl, suggesting that hymenin is a competitive antagonist of -adrenoceptors in vascular smooth muscles.Acknowledgments. We thank Ms A. Kajiwara and Ms M. Hamashima of this institute for their technical assistance, and Prof. Y. Hirata of Meijo University for his encouragement.  相似文献   

6.
Summary 26-Hydroxy--ecdysone has been identified as a metabolite of the moulting hormone, -ecdysone inCalliphora erythrocephala.  相似文献   

7.
Summary Electron microscopy demonstrated the presence of glycocalyx on the cell surface ofChattonella antiqua, which was previously believed to be naked. Histochemical analysis of this structure indicates that the glycocalyx consists of at least two different types of acidic complex carbohydrates, sulfated and nonsulfated, together with a neural carbohydrate-protein complex with 1,2-glycol groups and -D-mannosyl and -D-glucosyl residues.  相似文献   

8.
ATP-dependent potassium (KATP) channels occupy a key position in the control of insulin release from the pancreatic β cell since they couple cell polarity to metabolism. These channels close when more ATP is produced via glucose metabolism. They are also controlled by sulfonylureas, a class of drugs used in type 2 diabetic patients for triggering insulin secretion from β cells that have lost part of their sensitivity to glucose. We have demonstrated the existence of endogenous counterparts to sulfonylureas which we have called ‘endosulfines.’ In this review, we describe the discovery, isolation, cloning, and biological features of the high-molecular-mass form, α-endosulfine, and discuss its possible role in the physiology of the β cell as well as in pathology. Received 1 February 1999; received after revision 26 March 1999; accepted 26 March 1999  相似文献   

9.
Casein,a prohormone with an immunomodulating role for the newborn?   总被引:3,自引:0,他引:3  
Summary Maternal colostrum and milk, the earliest food of the newborn, should not only be considered as supplying nutrients, but also as agents providing protection against aggressions from the new environment. Indeed by enzymatic digestion of the main milk proteins, the caseins, biologically active peptides are released; they may be implicated in the stimulation of the newborn's immune system. From this point of view a strategic active zone has been characterized in -casein. A possible role of casein as a prohormone for the newborn is suggested.  相似文献   

10.
Summary The compound, 3,5-dibromo-2-chloro-4-isothiocyanatosalicylanilide, has been tested against various nematode and cestode parasites in experimental and domestric animals. It shoved 100% activity againstAncylostoma ceylanicum, A. tubaeformis, Syphacia obvelata, Ascaridia galli, Toxocara spp.,Toxascaris sp.,Gnathostoma spinigerum, Hymenolepis nana, Raillietina spp. andTaenia spp. in doses 25–70 mg/kg given in single or multiple administrations.Acknowledgments. We express sincere thanks to Dr Nitya Nand, F.N.A., CDRI, Lucknow, for his keen interest in the work, to Dr B. N. Dhawan, F.N.A. for providing informations about general pharmacology of the compound, and to Dr R. K. Chatterjee and Dr P. K. Murthy for carrying out antifilarial sreening. Technical assistance of Mr S. C. Bhar and Mr S. Ram is acknowledged.  相似文献   

11.
The isolation of N-quinaldyl-L-arginine·HCl (1) from the CoccinellidaeSubcoccinella-24-punctata is reported. The structure, first established on the basis of the analysis of the spectral properties of1, has been confirmed by synthesis. The alkaloid is of endogenous origin and markedly deterrent to ants.  相似文献   

12.
Summary The profile of action in animals of CQP 201-403, a novel 8-amino-ergoline, is in most aspects that of a very potent dopaminomimetic, both as a prolactin secretion inhibitor, and at the levels of the CNS and the cardiovascular system. Qualitatively CQP 201-403 differs slightly from bromocriptine and apomorphine in its effects on the CNS (no influence on serotonin metabolism in the rat cortex; induction of masculine mounting behavior in rats) and the cardiovascular system of the dog (reflex tachycardia in response to a blood-pressure fall). In man the new compound proved to be highly active in lowering prolactin serum levels and to be more potent than bromocriptine (Parlodel®).In memory of Dr Annemarie Closse, who died 14 June 1987.  相似文献   

13.
Summary A new enantiomeric sesquiterpene alcohol named (–)-maalian-5-ol was isolated from the liverwort, and the structure and absolute configuration was determined to be the stereostructureI by chemical and spectral evidence.The authors express their gratitude to Dr H. Inoue, National Science Museum, for identification of the liverwort, and Prof. T. Tokoroyama, Osaka City University, for sending of the data of (–)--maaliene and (+)-selina-5,11-diene. Thanks are also due to the Ministry of Education for financial support of this work.  相似文献   

14.
Streptomyces cacaoi -lactamase genes are controlled by two regulators named blaA and blaB. Whereas BlaA has been identified as a LysR-type activator, the function of BlaB is still unknown. Its primary structure is similar to that of the serine penicillin-recognizing enzymes (PREs). Indeed, the SXXK and KTG motifs are perfectly conserved in BlaB, whereas the common SXN element found in PREs is replaced by a SDG motif. Site-directed mutations were introduced in these motifs and they all disturb -lactamase regulation. A water-soluble form of BlaB was also overexpressed in the Streptomyces lividans TK24 cytoplasm and purified. To elucidate the activity of BlaB, several compounds recognized by PREs were tested. BlaB could be acylated by some of them, and it can therefore be considered as a penicillin-binding protein. BlaB is devoid of -lactamase, D-aminopeptidase, DD-carboxypeptidase or thiolesterase activity.Received 13 January 2003; received after revision 9 April 2003; accepted 11 April 2003  相似文献   

15.
Summary The article surveys our knowledge of the normalizing factor, gained from its discovery a quarter of a century ago up to the present time, under the following headings: Discovery; Physiological properties; Isolation and characterization; Structure determination (Identity of the normalizing factor with nicotianamine); Chemical properties; Analysis; Synthesis; Occurrence and physiological role; Related compounds; Prospects.  相似文献   

16.
Zusammenfassung Eine genetisch bedingte Bewegungsstörung in der Hausmaus «reeler» wurde untersucht. Der Erbgang der «reeler»-Mutation ist einfach rezessiv. In homozygotem Zustand führt das Gen zu Gleichgewichtsstörungen und leichtem Zittern.Das Studium der Morphologie des Gehirns der «reeler»-Mäuse ergab, dass die Cytoarchitektonik des Kleinhirns in dieser Mutante verändert und teilweise zerstört ist.

Supported by Grant No. B-1716 from USPHS National Institute of Neurological Diseases and Blindness.  相似文献   

17.
Summary The benzodiazepine triazolam, the benzodiazepine inverse agonist, -methyl carboline (-CCM) or both, were administered to adult male hamsters under conditions of constant light. When given alone, triazolam induced phase advances in the circadian activity rhythm of about 90 min, while -CCM when given alone, had no effect on phase of the activity rhythm. However, when triazolam and -CCM were given at the same time, the magnitude of the phase advances induced by triazolam were attenuated to about 30 min. These data, in conjunction with previous results, provide pharmacological evidence for a GABAergic system involved in the regulation of a central circadian pacemaker.  相似文献   

18.
Summary A novel bromine-containing alkaloid, hymenin, has been isolated from the Okinawan marine spongeHymeniacidon sp. as a potent -adrenoceptor blocking agent and its structure determined to be1 on the basis of the spectral data.  相似文献   

19.
The short-term effects of leptin and a β3-adrenoceptor agonist on thermogenesis and expression of uncoupling proteins (UCPs) in brown adipose tissue (BAT) and muscle and their possible interactions were assessed. One hour after administration of the β3-adrenoceptor agonist Trecadrine, a statistically significant increase in UCP1 messenger RNA (mRNA) expression in BAT was observed, whereas UCP2 and UCP3 in both BAT and gastrocnemius muscle were unaffected. Leptin induced an upregulation of UCP3 mRNA in muscle, with no changes in BAT UCP1 mRNA. A statistical interaction was found between leptin and Trecadrine in rectal temperature. The present study provides evidence, for the first time, of the induction of UCP3 mRNA expression in skeletal muscle by leptin in nongenetically obese animals. Received 5 March 1999; received after revision 19 April 1999; accepted 21 April 1999  相似文献   

20.
Résumé Le mécanisme d'action des esters carboxyliques de la choline commence, probablement, par une hydrolyse enzymatique provoquée par une des cholinestérases. Les produits de l'hydrolyse réagissent avec un facteur inconnu, dont la spécificité est cependant définissable par la structure du résidu cholinique.  相似文献   

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