Inhibition of human testicular glucose-6-phosphate dehydrogenase by unsaturated C19-steroids

Zusammenfassung Die Bebrütung einer gereinigten G-6-PDH aus menschlichem Testisgewebe mit 3-substituierten ⁴- oder ⁵-C₁₉-Steroiden zeigte, dass 3-Hydroxy-⁴-oder ⁵-androsten-17-on auch wirksame Inhibitoren der testikulären G-6-PDH darstellen. Zur gleichen Zeit konnten die früher gefundenen Zusammenhänge zwischen chemischer Struktur eines Steroids und seiner biologischen Aktivität im G-6-PDH-Hemmtest uneingeschränkt bestätigt werden.     

The antifertility action of α-chlorohydrin: metabolism by rat and boar sperm

Summary The male antifertility agent -chlorohydrin (I) is metabolized by rat and boar sperm to -chloroactaldehyde (III), -chlorolactate (IV) and Cl^– and not to the proposed active metabolite, -chlorohydrin-1-phosphate (III). It is proposed that -chlorolactaldehyde is produced intracellularly by a specific enzyme and that this is the metabolite responsible for the species-specific antifertility activity of -chlorohydrin.This work was supported by The National Health and Medical Research Council of Australia.     

(−)-Δ8-tetrahydrocannabinol: Two novel in vitro metabolites

Zusammenfassung (–)-⁸-Tetrahydrocannabinol ist einer der Aktivstoffe in Marihuana (Cannabis sativa L.). Inkubation dieser Verbindung mit der überstehenden Zentrifugationsfraktion (9000g) aus männlicher Hundeleber ergab zwei Hauptmetaboliten, welche durch Massenspektrometrie und Kernresonanzspektroskopie identifiziert wurden. Den beiden Verbindungen werden die Strukturen des 1-Hydroxy-⁸-tetrahydrocannabinols und des 3-Hydroxy-⁸-tetrahydrocannabinols zugeordnet.     

The benzilic acid rearrangement of 3α,17β-Diacetoxy-11-hydroxy-12-oxo-5β-androst-9(11)-ene

Zusammenfassung Die Bildung von 11-Carboxy-3, 11, 17-trihydroxy-13-C-nor-5-androstan 11a,17-Lakton aus 3, 17-Diacetoxy-11-hydroxy-12-oxo-5-⁹(11)-androsten wird beschrieben. Der Mechanismus und die Stereochemie dieser Umwandlung (Retro-Aldolkondensation und Benzilsäureumlagerung) wird diskutiert.     

Effect of cadmium on polyribosome structure and function in mouse liver

Summary Cadmium chloride injected to mice (20 moles/kg) provokes in the livers a degradation of polyribosomes and diminishes their protein synthetic ability measured in vitro. CdCl₂ added in a final concentrations between 30 and 100 M to the protein synthetic cell-free system derived from livers of control mice inhibits its activity.Acknowledgments. We are grateful to Prof. P. Sokoli for helpful discussion. The work was supported by Wellcome Trust grant and by a gift of chemicals from Kemika, Zagreb. We are grateful to both these organizations.     

DDT: The degradation of ring-labeled14C-DDT to14CO2 in the rat

Summary Ring fission ofp, p-DDT was studied in the rat following a single oral dose of 0.74 mg/kg (1.04 Ci) of uniformly ring-labeled¹⁴C-DDT. Expired air was passed through a solution of ethanolamine-ethylene glycol monomethyl ether (12) to trap¹⁴CO₂. A total of 1.6% of the radioactivity administered was recovered in the expired air collected continually for 10 days, indicating that while degradation of the phenyl moiety is not a major route pfp, p-DDT metabolism in the rat, it is equal to the urinary excretion. Nevertheless, these results represent the most radical change accomplished in vivo of a residual insecticide yet reported in mammals.Acknowledgment. We acknowledge the secretarial work of Ms.Elaine Smolko. This study was supported by NIH fellowship No. 1 F22 ES01723-01 and No. HL16264.     

Antimalarial activity of racemic 3-Epidihydroquinine, 3-Epidihydroquinidine and their various racemic analogs in mice infected withPlasmodium berghei

Zusammenfassung Ein Vergleich dieser Resultate mit denjenigen, die wir für (±)-Dihydrochinin und (±)-Dihydrochinidin berichtet haben², bestätigt die Ergebnisse anderer Arbeiten⁴, dass Inversion am C-3 nur eine geringe Abnahme der Aktivität zur Folge hat. Die folgenden Aktivitäten gegenPlasmodium berghei in Mäusen² wurden in abnehmender Ordnung festgestellt: Dihydrochinidin>Dihydrochinin3-Epidihydrochinidin>3-Epidihydrochinin. Die Ersetzung der 6-Methoxygruppe mit einer 6, 7-Methylendioxy- oder 7-Chlorgruppe ist eine wirksame Abwandlung; die 7-Chlorderivate scheinen bisher die wirksamsten Verbindungen sowohl in der 3-Epials auch in dernormalen Serie zu sein².     

Deuterium isotope effects in the ninhydrin reaction of primary amines

Summary The rate of development of Ruhemann's purple in the ninhydrin reaction of two deuterated primary amines, -d₂-p-tyramine and -d₂--phenylethylamine, is significantly reduced It appears to be a primary isotope effect and indicates that the cleavage of the carbon-hydrogen bond at the -position is involved in the rate-determining step of the color reaction.Acknowledgements. We thank Dr A.A. Boulton for his advice and encouragement and the Canadian Medical Research Councel and Saskatchewan Health for their continuing financial support.     

Muscle-relaxant properties of a steroid bis-quaternary ammonium salt

Résumé Un stéroïde quaternaire (3,17-dipyrrolidin-1-yl-5-androstane bisméthiodide) administré par voie intraveineuse provoque une paralysie neuromusculaire compétitive d'une durée fugace chez le lapin, le poussin, le chat et le chien, mais l'action est un peu plus prolongée chez le singe et chez l'homme.     

1,2-Methylen-19-nor-17α-acetoxy-progesteron

Summary The syntheses and structure-determinations of 1, 22- and 1, 2-methylene-19-nor-17-acetoxy-progesterones described prove that there is no influence of the angular C₁₀-methylgroup on the steric course of theCourey-methylenations of ¹-3-keto-steroids.     

Evidence for the existence of 2 types of α1-lipoprotein in amniotic fluid from pregnancies older than 20 weeks

Summary We have found by means of crossed immunoelectrophoresis that amniotic fluid contains 2 types of ₁-lipoprotein after the 20th week of pregnancy. Before that period the ₁-lipoprotein profile of amniotic fluid resembles that of serum and migrates as one type only.     

Strukturspezifischer Abbau von Polypeptid-Metall-Komplexen III 1. Abbau des Ni2+-Angiotensin II-Komplexes durch H2O2 2

Summary The octapeptide Val⁵-Angiotensin II-Asp¹--amide is split into characteristic fragments by hydrogen peroxide, when complexed with Ni²⁺; this degradation does not occur with the Cu²⁺ complex, presumably because an active ternary peroxo complex cannot be formed.     

Versuche zum enzymatischen Abbau der «gebundenen» gibberelline vonPharbitis purpurea

Summary Seeds and fruit walls ofPharbitis purpurea contain in addition to the free gibberellins A₈, A₃, A₅, more polar gibberellin-like substances, so-called bound gibberellins tentatively namedPharbitis and. After purification by thin layer chromatography, these 2 substances were treated with both Ficin and Emulsin in buffered solutions of pH 6.2. After treatment with Emulsin, the free gibberellins A₈ and A₅, after treatment with Ficin the gibberellins A₃ and A₅, were detectable in thin layer chromatograms.     

Dissociation constants of the complexes between RNA-polymerase II and amanitins

Riassunto Sono state calcolate le costanti di dissociazione dei complessi fra la RNA-polimerasi II e la metil--amanitina, la -amanitina e la metil-aldoamanitina. La K _d è risultata essere 3.6×10^–9 M per la metil--amanitina e 3.2×10^–9 M per la -amanitina. La metil-aldoamanitina non si lega all'enzima.     

Nouvelles données sur la cytogénétique et la spéciation des Leggada (Mammalia-Rodentia-Muridae)

Summary To the 237 pigmy-mice studies in his previous papers, the author brings new data concerning the cytogenetics of 25 Leggada. One first set of 12 mice from Nigeria belongs to the same polymorphic series containing themusculoides from the Ivory Coast and the Central African Republic.A small sample from Ippy (Central African Republic), although the individuals are morphologically all alike and referable tomusculoides, shows an amazing diversity: /259.2N=28, N.F.=36, sex chromosomes of the translocated type (TR). We meet here a new robertsonian combination in the polymorphic series, 34/33/32/31 ... 28/... 22/... 19/18./260.2N=32, N.F.=36, sex chromosomesTR. Both big biarmed autosomes are metacentric — submetacentric with a centromeric index of about 0.25 by the typicalmusculoides having the same diploid number./261.2N=19, N.F.=36, sex chromosomesX/Y ₁ Y ₂. The first occurrence of such sex chromosomes by the Leggada. By themusculoides from Rhodesia we were dealing with the typeX ₁ X ₂ /Y. /262.2N=18, N.F.=36, sex chromosomesX/X. Very likely the female of /261.In the complexminutoides-musculoides, we meet many different caryotypes and it is obvious that the chromosomal mutations play here the part of a primary factor of isolation, previous to the gene mutations which later will allow the taxonomic determination of the species actually in statu nascendi.     

Enzymatic reactions in the presence of non-ionic polymers

Zusammenfassung Die enzymatische Spaltungsgeschwindigkeit von synthetischer hochmolekularer Stärke mit-Amylase wird in Gegenwart von neutralen (nicht ionogenen) Polymeren erhöht. Die katalytische Wirkung hängt von der Konzentration des Polymeren und dessen Molekulargewicht ab. Die Zunahme der-Amylase-Hemmung durch spezifische-Amylase-Antikörper in Gegenwart von neutralem Dextran wird nachgewiesen.     

Cytogénétique desLeggada: (1) La formule chromosomique deMus (Leggada)bufo Th., (2) Nouvelles données sur la délétion portant sur le bras court d'unX chezMus (Leggada)triton Th

Summary The author treats 2 topics connected with his studies on the cytogenetics of the African pigmy-mice. (1)Mus (Leggada) bufo Th. shows the primitive complement already detected in other species or subspecies (minutoides ssp ₁,indutus, tenellus, setulosus): 2N=36,N.F.=36, sex chromosomesPR. (2) The deletion of the short arm of oneX-chromosome (X _dc ) was previously observed as heterozygous mutation by 4 in a sample of 7 and 5 . A more important sample (18 , 21 ) gives the following results: 11 X-X, 10 X-X _dc , 18 X-Y. The occurrence of X _dc -X _dc and of X _dc -Y is also very improbable. It is not easy to understand how the chromosomeX _dc may persist in the population if the complementsX _dc -X _dc andX _dc -Y are lethal, which seems to result from these observations.     

Der durch circadiane Frequenzänderung entstehende Fehler bei der Bestimmung von Phasenverschiebungen

Summary Phase shifts () are commonly measured without considering the cue's phase position ( _s ). The normally adopted methods for measuring phase shifts give errorless results only when there is no change in period length (). Very often, however, both phase shifts and changes in period length occur together. The magnitude of the error is then a function of the magnitude of and the distance between the points of measurement and the cue's phase position. (The basic hypothesis is that is effected immediately after the cue.) Methods for calculating and eliminating the error are given.     

The in vivo expression of the globin genes of theβ cistron in γ-,δ-, andδβ-thalassemia heterozygotes

There is considerable evidence suggesting that the switch from to and chain production after birth is due, in part, to silencing of the genes by stage-specific factors which bind to their promoters and to the competition from the adult ( and ) genes for a common enhancer element located in the locus control region. As a consequence one can expect that the increased Hb F production in adults with hereditary persistence of fetal hemoglobin or -thalassemia is directed mainly by -globin genes in cis to the deletion(s) responsible for these conditions. Here we review data on heterozygotes with -, -, or -thalassemia, who also had an^AT mutation, in cis or in trans, which was used as a marker of gene expression. The results show that a deletion affecting adult genes favors the expression of genes in cis, while the deletion of a single gene does not affect the expression of the gene in cis but leads to a faster switch postnatally.