Pigment formation from tyrosine derivatives by UV-irradiation in thin-layer chromatography

Zusammenfassung Nach Bestrahlung mit UV- und ge-, wöhnlichem Licht entstehen in Dünnschichtchromatogrammen von Tyrosin, Thyronin und ihren Jodderivaten wie auch Dopa und Dopamin dunkle Flecken an den entsprechenden Stellen dieser Substanzen. UV-Licht ist für das Auftreten der Pigmente verantwortlich, welche melaninähnliche Polymere zu sein scheinen.     

Activation of virus production by DMSO in C. albicans experimentally infected with polyoma-DNA

Zusammenfassung Die Infektion von Schimmelpilzen,C. albicans, durch Polyomavirus mit isolierter Polyoma-DNS und die aktivierende Wirkung von DMSO werden beschrieben.

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Supported by a grant of the National Cancer Institute of Canada.

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The assistance of Mr. G.Kolompár and B.Bucz during these assays is gratefully acknowledged.     

Changes in the ultrastructure of erythrocyte membrane subjected to UV-irradiation in vitro

Résumé Nous avons étudié l'effet des rayons UV sur l'ultrastructure des globules rouges des mammifères. L'examen électronoscopique montre qu'après ce rayonnement la membrane des globules rouges devient moins granulaire et moins épaisse. La répartition de ses plis ressemble à celle que présentent les globules plus vieux ou atteints de défauts enzymatiques (p. ex. le manque de G-6-PD).

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Acknowledgments. The authors with to express their gratitude to Prof.M. Olszewska for her advice in interpretation of electron microscope photograms.     

Changes in hydroxyproline content of human dermal collagen following UV-irradiation in vitro

Zusammenfassung UV-Bestrahlungen von menschlichem dermalem Kollagen führen in vitro zu einer Zunahme des Hydroxyprolingehaltes.     

Lipid accumulation by a cellulolytic strain ofAspergillus niger

Lipid accumulation by a cellulolytic mold,Aspergillus niger, was studied. The amount of lipid accumulated ranged from 13.6–16.6% on various carbon sources, namely glucose, xylose, avicel (microcrystalline cellulose) and bagasse (a natural lignocellulosic substrate). Neutral lipids, phospholipids and glycolipids of the mycelia varied from 41.0–46.2%, 34.9–38.4% and 18.7–22.6% of total lipids, respectively. Unsaturated fatty acids comprised around 80% of total fatty materials with linoleic and oleic acid predominating. Of the four nitrogen sources tested, NH₄Cl was the best source for lipid synthesis from cellulose (bagasse). Optimum temperature range for growth and lipid synthesis was 25–30°C.     

Porphobilinogen-accumulation by a porphyrin auxotrophic strain ofBacillus subtilis

Summary The amount of porphobilinogen accumulated by aBacillus subtilis hemC mutant strain is dependent on time and exogenic aminolevulinic acid addition.hemC mutant seems to be suitable for porphobilinogen production on a large scale.Acknowledgments. We thank Prof. I. Bélàdi for renewing our interest in pophyrin auxotrophs and for her current help.     

Activation of complement by trypanosomes

Summary Factors exhibiting anti-complementary activity released from trypanosomes after incubation at 20°C were described. The active material was shown to consume the first component of bovine complement. While the anticomplementary factor(s) from T. lewisi could activate bovine, human and guinea pig complement, the factor(s) from T. congolense was observed to activate bovine complement, but not guinea pig and only slightly human complement. The roles of complement activating factor(s) of trypanosomes in the pathology of the disease are discussed.This project is supported by National Research Council of Canada grant A 0068 and a grant from the International Development Research Centre.     

Lipid accumulation by a cellulolytic strain of Aspergillus niger.

Lipid accumulation by a cellulolytic mold, Aspergillus niger, was studied. The amount of lipid accumulated ranged from 13.6-16.6% on various carbon sources, namely glucose, xylose, avicel (microcrystalline cellulose) and bagasse (a natural lignocellulosic substrate). Neutral lipids, phospholipids and glycolipids of the mycelia varied from 41.0-46.2%, 34.9-38.4% and 18.7-22.6% of total lipids, respectively. Unsaturated fatty acids comprised around 80% of total fatty materials with linoleic and oleic acid predominating. Of the four nitrogen sources tested, NH4Cl was the best source for lipid synthesis from cellulose (bagasse). Optimum temperature range for growth and lipid synthesis was 25-30 degrees C.     

Activation of complement by trypanosomes.

Factors exhibiting anti-complementary activity released from trypanosomes after incubation at 20 degrees C were described. The active material was shown to consume the first component of bovine complement. While the anti-complementary factor(s) from T. lewisi could activate bovine, human and guinea pig complement, the factor(s) from T. congolense was observed to activate bovine complement, but not guinea pig and only slightly human complement. The roles of complement activating factor(s) of trypanosomes in the pathology of the disease are discussed.     

The effect of heat-treatment and UV-irradiation on X-ray induced electron spin resonance centers in valine

Zusammenfassung Nach Röntgenbestrahlung von polykristallinemdl-Valin bei Zimmertemperatur ergibt sich ein ESR-Spektrum ohne aufgelöste Hyperfeinstruktur. Erwärmt man die bestrahlte Substanz auf 353 °K, so zeigt das Spektrum mehrere gut aufgelöste Tripletts. Demnach ist die intermolekulare Radikalwanderung bei Zimmertemperatur noch nicht abgeschlossen, sondern erst nach weiterer Temperaturerhöhung.     

Confirmation of the structure of nisin and its major degradation product by FAB-MS and FAB-MS/MS

Summary FAB-MS has been applied to the analysis of a nisin complex and FAB-MS and FAB-MS/MS data from the major component used to provide confirmation of the amino sequence and positions of the sulphur-bridged rings in these highly modified peptides.     

Presence of viruses in a strain ofMycoplasma pulmonis

Summary Filtrates prepared from heavily grown agar cultures ofM. pulmonis strain Negroni-52 formed plaques on lawns ofA. laidlawii strain JA1 but not on those ofM. pulmonis strains Ash or Negroni-52. The plaque-forming agent proved to be rod-shaped particles morphologically identical with mycoplasmavirus group 1. Evidence supporting the conclusion that the virus originated from Negroni-52 has been obtained. Electron microscopy revelaed that Negroni-52 is also a carrier of long-tailed phage-like particles.     

A new actinomycin-like antibiotic produced by a mutant strain ofStreptomyces indicus

Zusammenfassung Aus einer Mutante vonStreptomyces indicus Chakrabarty sp. nov. wurde das neue Antibiotikum MT-10 (orange-gelbe Kristalle) isoliert. Die antibakterielle und antifungische Aktivität wurde untersucht und festgestellt, dass MT-10 mit Actinomycin D verwandt ist.     

Confirmation of the structure of nisin and its major degradation product by FAB-MS and FAB-MS/MS

FAB-MS has been applied to the analysis of a nisin complex and FAB-MS and FAB-MS/MS data from the major component used to provide confirmation of the amino sequence and positions of the sulphur-bridged rings in these highly modified peptides.     

Activation of subtilisin by luteotropic and luteinizing hormone

Zusammenfassung Die Katalysegeschwindigkeit der Hydrolyse vonN-l-Leucyl-2-naphthylamin durch Subtilisin war grösser in Gegenwart von luteotrophem Schafhormon und etwas geringer in Gegenwart von luteinisierendem Pferdehormon. Dieses Verhalten wird als kompetitive Aktivierung erklärt.     

The production of leucylphenylalanine anhydride by a variant ofStreptomyces noursei

Résumé A partir de cultures deStreptomyces noursei, variante No. 5286, on a isolé la 3-benzyl-6-isobutyl-2, 5-dioxopipérazine, en plus des quatre dioxopipérazines disubstituées dont la présence a été signalée précédemment; on n'a pas obtenu de preuve de l'existence d'un dérivé 3-benzylidène-6-isobutyl-ou 3-benzyl-6-isobutylidènecorrespondant à la 3-benzyl-6-benzylidène-2,5-dioxopipérazine déjà connue.     

Production of ergotamine by a strain ofClaviceps purpurea (Fr.) Tul.

Riassunto Un ceppo diClaviceps purpurea indicato con la sigla 275 F.I. produce in coltura sommersa 1100–1500g/ml di una miscela di alcaloidi peptidici costituita principalmente da ergotammina (80%). Sono riportati i terreni colturali, le condizioni di coltura e l'andamento di una tipica fermentazione.     

Abnormal development of phialides in a strain ofAspergillus niger

Summary AnAspergillus niger mutant strain (hpp) produces an average of 4.1% of conidiophores with phialide proliferations. Increased frequency of proliferations could be induced on all studied strains by growth on potato dextrose agar. The characteristic is recessive and seems to be due to a pleiotropic effect of the mutation for olive conidia color.Acknowledgments. The authors are indebted to CNPq for financial assistance provided with grant PIG/SIP 04/053 as well as the scholarships Pesquisador Científico (R.B.Jr) and Iniciação Científica and Aperfeiçoamento (G.U.V.).