Über neue geminale aminocarbinole

Summary By reacting dopa, -methyl- and -ethyldopa and the corresponding esters with aldehydes geminate amino-carbinols of the general formula I can be prepared. The acetylation of the adduct of -methyldopa-methylester with acetaldehyde and benzaldehyde and the resolution of the latter compound withd-tartaric acid is described.     

Acetaldehyde metabolism inDrosophila melanogaster

Summary A quantitative study on in vitro acetaldehyde degradation in homogenates fromDrosophila melanogaster files shows that aldehyde oxidase plays the major part in acetaldehyde detoxification. However, in a strain, celed AO null, because itsAldox locus produces no aldehyde-oxidase, acetaldehyde is also degradated by a still unknown mechanism. Alcoholdehydrogenase which is responsible for the dehydrogenation of ethanol in acetaldehyde, appears to catalyze the reversed reactions as wel, regenerating ethanol fromacetaldehyde.This work was supported in part by a grant from the FNRS of Belgium.     

The tonically acting pulmonary receptors innervated by C fibres

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How canDrosophila flies without aldehyde oxidase detoxify acetaldehyde

Summary The flies of aDrosophila melanogaster strain, called AO null as it lacks the enzyme aldehyde oxidase, are nevertheless able to detoxify acetaldehyde. It seems that this action could be attributed to aldehyde dehydrogenase, or some other enzyme which ressembles aldehyde dehydrogenase.This work was supported in part by a grant from the FNRS of Belgium.     

The role of repair in radiobiology

Summary Apart from cancer and mutation induction, radiobiological effects on mammals are mostly attributable to cell death, defined as loss of proliferative capacity. Survival curves relate retention of that capacity to radiation dose, and often manifest a quasi-threshold (shoulder). The shoulder is attributable to an initial mechanism of repair (Q-repair) which is gradually depleted as dose increases. Another form of repair, which is not depleted (P-repair), increases the dose required to deliver an average of one lethal event per cell (dose D₀). Neither form of repair can unambiguously be linked with repair of defects in isolated DNA. An important initial lesion may well be disruption of the complex structural relationship between the DNA, nuclear membrane and associated proteins. One form of P-repair may be restoration of that structural relationship.     

The synthesis of jaceidin

Zusammenfassung Durch Kondensation nachAllan-Robinson wurde aus 2,4,6-Trihydroxy-3, -dimethoxy-acetophenon das 4-Benzyloxy-5,7-dihydroxy-3,6,3-trimethoxyflavon dargestellt. Entbenzylierung in C-4-Stellung führte zum 5,7,4-Trihydroxy-3,6,3-trimethoxyflavon. Die Eigenschaften dieser Verbindung und ihre Derivate sind identisch mit dem ausCentaurea jacea L. isolierten Jaceidin bzw. seinen Derivaten.     

The synthesis of ecdysone

Zusammenfassung Ecdyson, ein Häutungshormon der Insekten, wurde ausgehend von Ergosterin in 14 Stufen synthetisiert. Wesentliche Zwischenprodukte waren (20S)-2, 3-Diacetoxy-20-formyl-5-pregn-7-en-6-on und (22R)-2, 3-Diacetoxy-14, 22-dihydroxy-25-(tetrahydropyran-2-yloxy)-5-cholest-7-en-6-on.     

The addition of ethyl azodicarboxylate to pyrroles

Zusammenfassung Es reagieren die - und -Positionen von Pyrrol-Derivaten ohne weiteres mit thyl-Azodicarboxylat unter Bildung von Hydrazindicarboxyester-Derivaten, was durch die NMR- und IR-Spektren bestätigt wird.     

The stimulating action of gastrin pentapeptide,histamine and cyclic adenosine 3′,5′-monophosphate on carbonic anhydrase in rat stomach

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With the technical assistance ofYu. M. Konstantinov andT. V. Zymonina.     

The selective esterification of the 5′-hydroxyl of thymidine

Zusammenfassung Ein einfacher Weg zur selektiven Esterbildung mit der 5-Hydroxylgruppe von Thymidin wird beschrieben. Beispiele: Thymidin-5-phosphat, Thymidin-5-sulfat und Thymidin-5-trichloracetat.     

The red impurity in trypan blue

Zusammenfassung Isolierung und Strukturaufklärung der roten Komponente des teratogenen und karzinogenen Farbstoffs Trypanblau: 8-ammo-2-(3, 3-Dimethylbiphenyl-4azo)-naphth-1-ol-3,6-Disulphonsäure.     

Distinction entre les variations phénotypiques sexuelles et génétiques chez le Rat,par l'analyse immunoélectrophorétique des protéines urinaires spécifiques

Summary We show that phenotypical variations of rat urinary proteins are either sex-linked (variations at the rho-uroprotein and major urinary protein level) or related to the genetic purity (variations at the -uroprotein level).

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Travail subventionné par l'octroi n 362-10 du Conseil des Recherches médicales du Canada.     

The cellular immune response to heat shock proteins

T lymphocytes, which are central to almost every immune response, frequently recognize microbial hsp60. Such cells could provide an early defense mechanism against pathogenic microbes. However, T cells also recognize epitopes of hsp60 shared by microbe and host. Not only conventional / T cells respond to hsp60; / T cells do so, as well. In fact, certain / T cells seem to have a particular preference for this molecule. Recognition of stressed host cells expressing hsp60 could facilitate the scavenger function of the T cell system. On the other hand, such recognition could be involved in autoimmune disease.     

Antidiuretic effects of oxytocin in the Brattleboro rat

Summary The antidiuretic activity of oxytocin (OT) was measured in Brattleboro rats with congenital diabetes insipidus. A dose dependent antidiuretic response was found in animals receiving chronic infusions of 0.1 g/h, 1.0 g/h, and 5 g/h of OT. OT infused at the rate of 5 g/h over a 7-day period completely reversed the symptoms of diabetes insipidus. The results support the concept that OT serves as a weak agonist of vasopressin at the level of the kidney and at pharmacological levels exhibits antidiuretic activity.     

The inability of nuclear dehydrogenating clostridia to oxidize bile salt hydroxyl groups

Summary In a survey of the intracellular bile salt oxidoreductase activity in fecal bacteria, 16 strains of nuclear dehydrogenating clostridia and 2 strains of non-nuclear dehydrogenatingC. paraputrificum were demonstrated unable to oxidize cholate at any of the 3 OH groups. Since nuclear dehydrogenation at the -1 and -4 position requires a 3-oxo precursor steroid, it appears that these organisms require the presence of a 3-hydroxysteroid dehydrogenating organism for nuclear dehydrogenation.This work is supported by the National Cancer Institute of Canada (IAM) and by the Cancer Research Campaign (MJH).     

The rubremetinium and rubremetaminium cations

Zusammenfassung Spektroskopische und massenspektrometrische Daten bestätigen die Struktur (IV) für das Rubremetiniumkation. Rubremetaminiumsalze besitzen analoge Struktur mit einer zusätzlichen Doppelbindung in 3, 4-Stellung.     

The synthesis of isohalfordin

Zusammenfassung Die Synthese von Isohalfordin (3,4, 8-Trimethoxyfuro[3,2:6, 7]cumarin) aus 6,7-Dihydroxy-2, 3-dihydrobenzo[b]furan wird beschrieben.     

The detection of fraud and fakery

Summary Fraud is often found in science, especially in what is termed, fringe science. There are several reasons why scientists should be aware of the fact that they, too, can be deceived, both by subjects in experiments and by themselves. The will to believe is strong even among hard-headed academics, and is often the factor that causes them to publish results that do not stand up to subsequent examination and/or attempts to replicate. In some cases, scientists would be well advised to consult with such experts as conjurors, when skilled frauds are in a position to mislead them.     

Regulation of enzymes of ethanol metabolism in yeast (Rhodotorula gracilis)

Summary The three enzymes of ethanol metabolism alcohol dehydrogenase, aldehyde dehydrogenase and acetyl-CoA synthetase in the obligate aerobic yeastRhodotorula gracilis are repressed by glucose and induced by C₂ metabolic fuels with a regulatory pattern indicating a correlation in the control mechanisms. To try an identification of the molecular signals involved in the transmission of the inducing stimulus, experiments were carried out by blocking with 2 mM pyrazole the ethanol acetaldehyde metabolic step. Results indicate that ethanol is not specifically required as a molecular signal for induction.This work was supported by a grant from the Italian Consiglio Nazionale delle Ricerche.     

The effect of caerulein on epithelial growth in the mouse gall bladder

Summary Caerulein, a synthetic decapeptide, was injected into mice in order to study its effect on DNA-synthesis activity in the gall bladder epithelium. Histoautoradiography after the injection of labeled thymidine was used. Higher labeling indices were observed at 8, 12 and 24 h after caerulein injection. These data indicate that caerulein, apart from its cholecystokinetic effects, exerts a trophic effect on the gall bladder mucosa.Acknowledgements: this work was supported in part by the Fonds voor Geneeskundig Wetenschappelijk Onderzoek and by the Algemene Spaar- en Lijfrentekas.