The effect of γ-irradiation on the amount of 5-hydroxytryptamine in the gut and spleen in the early phase after irradiation

Résumé 24 et 48 h après irradiation- (900 r) la quantité de 5-hydroxytryptamine dans l'intestin du rat n'a pas changé de manière significative. La quantité de 5-hydroxytryptamine dans la rate du rat, exprimée par g de tissu frais a augmenté. Le prétraitement avec de la cystéamine abaisse nettement la quantité de 5-hydroxytryptamine dans la rate, après l'irradiation.     

Restoration of the poor oxygen transport function of ACD-stored blood by pyridoxal 5′-phosphate

Summary Pyridoxal 5-phosphate is easily incorporated into ACD-stored erythrocytes without decrease of ATP, and restores the poor oxygen transport function with a similar effect to 2,3-diphosphoglycerate.     

Metabolism in porifera VI. Role of the 5,6 double bond and the fate of the C-4 of cholesterol during the conversion into 3β-hydroxymethyl-A-nor-5α-steranes in the spongeAxinella verrucosa

Summary During the conversion of cholesterol into 3 -hydroxymethyl-A-nor-5-cholestane by the spongeAxinella verrucosa, the carbon-3 of this latter originate from carbon-4 of cholesterol. Cholestanol moreover does not seem an intermediate in this conversion.     

Synthesis and application of the photolabile guanosine 3′,5′-phosphoric-o-nitrobenzylester

Summary The o-nitrobenzylester of guanosine 3,5-phosphate is prepared and the photolysis studied. This photoactive form of cGMP should be an agent capable of altering the intracellular concentration of cGMP through membrane penetration and subsequent photolysis.Acknowledgments. We would like to thank the Deutsche Forschungsgemeinschaft and the Universität Konstanz for kindly supporting this research.     

Flow-induced release of adenosine 5′-triphosphate from endothelial cells of the rat mesenteric arterial bed

Adenosine 5-triphosphate (ATP) was released into the perfusate of rat isolated mesenteric arterial beds during each of two consecutive increases in flow. There was no significant difference between the amounts of ATP released on each occasion. Substance P was also released into the perfusate by increased flow, although its release was more variable. Removal of the endothelium of the mesenteric vessels with sodium deoxycholate led to a significant reduction (74%) in the amount of ATP released compared with the release before the endothelium had been removed. This suggests that the ATP released into the mesenteric arterial perfusate during increased flow arises from endothelial cells.     

Rôle of the nucleus in the maintenance of the protein level in the algaAcetabularia mediterranea

Riassunto Sono state studiate le variazioni del rapporto tra l'N proteico e non proteico in segmenti rigeneranti, nucleati ed anucleati, diAcetabul. medit. I risultati ottenuti hanno dimostrato che il predetto rapporto aumenta in entrambi i segmenti il primo giorno dopo l'operazione. Nei giorni seguenti esso diminuisce in entrambi i segmenti, ma più sensibilmente in quelli anucleati, nei quali va al di sotto del valore medio delle alghe normali già dopo il 3°–4° giorno.     

Poinsinet's Edition of the Naturalis historia (1771–1782) and the Revival of Pliny in the Sciences of the Enlightenment

This paper analyses the revival of Pliny's Naturalis historia within the scientific culture of the late eighteenth and early nineteenth centuries, focusing on a French effort to produce an edition with annotations by scientists and scholars. Between the Renaissance and the early eighteenth century, the Naturalis historia had declined in scientific importance. Increasingly, it was relegated to the humanities, as we demonstrate with a review of editions. For a variety of reasons, however, scientific interest in the Naturalis historia grew in the second half of the eighteenth century. Epitomizing this interest was a plan for a scientifically annotated, Latin-French edition of the Naturalis historia. Initially coordinated by the French governmental minister Malesherbes in the 1750s, the edition was imperfectly realized by Poinsinet a few decades later. It was intended to rival two of the period's other distinguished multi-volume books of knowledge, Diderot and D'Alembert's Encyclopédie and Buffon's Histoire naturelle, to which we compare it. Besides narrating the scientific revival of the Historia naturalis during this period, we examine its causes and the factors contributing to its end in the first half of the nineteenth century.     

Influence of the structure of theN-terminal extremity ofα-MSH on the melanophore stimulating activity of this hormone

Zusammenfassung Drei strukturelle Analoge des-MSH wurden synthetisiert und auf ihre Melanophoren-stimulierende Wirksamkeit untersucht. Für das Auftreten einer ausgeprägten biologischen Aktivität scheint die Anwesenheit einerN-Acetyl-Gruppe an dem Aminoende der Peptidkette wichtiger zu sein als das Vorhandensein der zwei ersten amino-endständigen Aminosäurereste der-MSH-Kette.     

A study of the temperature dependence of radiation sensitivity of dry spores ofBacillus Megaterium between 5° K and 309° K

Zusammenfassung Die Temperaturabhängigkeit der Röntgenstrahlenempfindlichkeit trockener Sporen vonBacillus megaterium wurde über einen Temperaturbereich von 5°K bis 309°K gemessen. Die Empfindlichkeit ist temperaturunabhängig unterhalb 130°K; sie entspricht der van-t'Hoff-Arrhenius-Regel zwischen 130°K und 310°K bei einer Aktivierungsenergie von 0,110 kcal.

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This work was performed under the auspices of the U.S. Atomic Energy Commission. — The assistance and advice of Dr.Darrell W. Osborne, Chemistry Division, Argonne National Laboratory, and his colleagues in producing and handling liquid He and liquid H are gratefully acknowledged.     

Influence of cyproterone acetate on the activity ofβ-glucuronidase in the hypothalamus and cerebral cortex of the male mouse

Summary Daily s.c. injections of cyproterone acetate greatly decrease the protein content and-glucuronidase activity in the mouse hypothalamus. These effects are reversible and the recovery capacity of the animal seems to be inversely related to the duration of antiandrogenic treatment.Financial aid was given by CNR (finalized project Biologia della Riproduzione) and Ministry of Education. Thanks are also due to Prof. G. Chieffi for suggestions and to Mr R. Auriemma for maintenance of experimental animals.     

Effects of duration of gonadectomy,sex and age on adrenal steroid 5α-reductase activity in the rat

Summary Within 6–8 weeks, gonadectomy in male and female rats leads to an increase in adrenal 5-steroid reductase activity. However, long-term post-orchiectomy enzyme activity decreases to the control level and this effect is not related to the age of animals.Supported in part by grant No.564/VI from Polish Academy of Sciences. Generous gift of hormones applied in these studies from The Upjohn Company, Kalamazoo, Michigan, USA is acknowledged.     

The effect of cyclic cytidine 3′,5′-monophosphate (cCMP) on the in vitro development,hatching and attachment of the mouse blastocyst

Summary The in vitro development and attachment of hatched mouse blastocysts on the untreated substratum was enhanced by 10 M dibutyryl cCMP (dbcCMP). The result suggests that cCMP has an effect on embryonic development and on the blastocyst attachment process.25 November1986     

The influence of N-methyl-N-β-chloroethyl hydrazines on the mitotic index of Ehrlich ascites tumor cells and the leukopoiesis of the mouse

Summary The cytostatic activity of N-methyl-N--chloroethylbenzaldehyd hydrazone, (B1) is at least equal to that of procarbazine when its effect is tested with the Ehrlich ascites tumor cells of the mouse and the Yoshida sarcoma of the rat. B1 causes a slighter decrease of mitotic cells and no shift from prophase to metaphase. These results suggest that the cytostatic effect of B1 is due to interference with cell metabolism or an effect at the cell membrane and not to an effect on cell proliferation. This assumption is supported by a considerable depression, of lymphocytes and a minor effect on granulopoiesis, which is especially sensitive towards proliferation toxins. All these findings suggest a different mechanism of action of B1 and procarbazine.     

IgG purification to measure the level of an iodinated thyroglobulin peptide,the 3,5,3′,5′ tetraiodo-l-tyrosyl-l-tyrosine in human serum

Summary Antibodies reacting with 3,5,3,5 tetraiodo-l-tyrosyl-l-tyrosine (I₂Tyr-I₂Tyr) were elicited in rabbits by immunization with an oxidized yeast conjugate coupled with I₂Tyr-I₂Tyr. Ion-exchange chromatography was used to purify immunoglobulins, in order to improve the specificity in measurement of I₂Tyr-I₂Tyr level in patient serum. IgG binding capacity versus I₂Tyr-I₂Tyr was considerably increased after immunoglobulin purification.Acknowledgments. The authors with to thank Mrs M. Ollier for her valuable technical assistance.     

Unraveling the pathogenesis of Parkinson’s disease – the contribution of monogenic forms

The field of Parkinsons disease pathogenesis is rapidly evolving from the one of a monolithic and obscure entity into the one of a complex scenario with several known molecular players. The ongoing systematic exploration of the genome holds great promise for the identification of the genetic factors conferring susceptibility to the common non-Mendelian forms of this disease. However, most of the progress of the last 5 years has come from the successful mapping and cloning of genes responsible for rare Mendelian variants of Parkinsons disease. These discoveries are providing tremendous help in understanding the molecular mechanisms of this devastating disease. Here we review the genetics of the monogenic forms of Parkinsons disease. Moreover, we focus on the mechanisms of disease caused by -synuclein and parkin mutations, and the implications of this growing body of knowledge for understanding the pathogenesis of the common forms of the disease. Received 10 March 2004; received after revision 26 April 2004; accepted 29 April 2004