Effect of protoplasting on antibiotic activity and resistance in the strain Streptomyces hygroscopicus 155]

The influence of protoplasting and protoplast regeneration in the presence of polyethylene glycol on antibiotic activity, components of antibiotic complexes and antibiotic resistance in Streptomyces hygroscopicus 155 was studied. It was shown that the protoplasting and protoplast regeneration influenced the antibiotic activity. The protoplast fusion resulted in increased isolation of variants with higher antibiotic activity. The processes also affected the components of the antibiotic complexes but had no effect on the strain resistance to some antibiotics.     

Various approaches to designing the functionally active determinants as illustrated by the influenza virus A(H3N2) hemagglutinin]

Hexapeptide Lys-Gly-Pro-Asp-Ser-Gly analogous to the immunodominant fragment 141-146 of the epitope A of the influenza virus A(H3N2) hemagglutinin is synthesized. Conjugated with thyroglobulin and hemocyanine, the hexapeptide induced formation of highly specific antibodies with heterolytic properties in CBA mice. Antihexapeptide antibodies interact not only with the homologous antigen but also with hemagglutinin and influenza virus. Choice of the hexapeptide sequence is discussed.     

Determination of interacting segments of tRNA(Leu) from cow mammary glands with homologous aminoacyl-tRNA-synthetase by a chemical modification method

The interaction of the cow mammary gland tRNA(IAGLeu), having a long variable loop, with the cognate aminoacyl-tRNA synthetase has been studied by the alkylation with ethylnitrosourea. It was shown that leucyl-tRNA synthetase protects from alkylation 3'-phosphates of the nucleotides 12-13 in D-loop, 23-24 in D-stem and 37-43 in the anticodon arm of tRNA(IAGLeu). All regions of interaction with the aminoacyl-tRNA synthetase are located in the same plane of tRNA whereas the long variable loop is in another plane.     

Effect of heterogeneity of the myocardium on its mechanical function

The influence of the mechanical heterogeneity on the myocardium contractility was evaluated. The heterogeneity was imitated by parallel connection of two papillar muscles with different mechanical properties. The rate of muscle shortening was controlled by a feed-back from tension of each of the muscles or both muscles simultaneously in the precision ergometer. The "force-velocity" and "length-force" relations were registered for each muscle independently, and in case of parallel connection of two muscles. It was shown that connection of two muscles in parallel influenced significantly the distribution of load in the muscles, maximal and mean velocity of their shortening. It is stated that the key phenomenon controlling the value and the heterogeneity influence sign is mechano-chemical uncoupling (inactivation).     

Book reviews

Ohne Zusammenfassung

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Book reviews

     

Abbau chlorierter Benzole,Phenole und Cyclohexan-Derivate durch Benzol und Phenol verwertende Bodenbakterien unter aeroben Bedingungen

From soil samples of different origin (field, grassland and forest soils) small numbers ofNocardin andPseudomonas spec., able to utilize benzene and phenol could be isolated. Organisms which could only utilize phenol and phenolcarboxylic acids were more numerous and consisted mainly ofArthrobacter spec. It was tested to what extent these organisms could also utilize chlorinated aromatic and cyclohexane derivatives. For the degradation studies the bacteria were precultivated on benzene or p-hydroxybenzoic acid and then the compounds used were added. These compounds were labeled by¹⁴C and their degradation rates determined by measuring the¹⁴CO₂ release.Pseudomonas andNocardia spec. precultivated on benzene could also degrade the chlorinated derivatives of benzene and phenol. The monochlorinated derivates were degraded more easily than the di- and trichlorinated derivates. The chlorinated benzenes, especially in higher concentrations, were less degraded than the chlorinated phenols, but with lower concentrations their degradation rates were about similar. This was due to a higher toxicity of the benzenes. The phenol utilizingArthrobacter spec. were only able to degrade phenol and the chlorinated phenols. Benzoic and m-chlorobenzoic acid were degraded to CO₂ by thePseudomonas andNocardia spec. only. The benzene utilizing pseudomonads released more CO₂ from γ-pentachlorocyclohexane than from γ-hexachlorocyclohexane, but none from cyclehexane. Upon precultivation of benzene utilizing pseudomonads in glucose, the aromatic compounds were also degraded, but especially the chlorinated derivatives to a lower extent. In comparison with these soil organisms in pure culture, experiments with soil samples showed a degradation of all compounds which were used by the isolated organisms after variable induction periods. Cyclohexane was degraded slowly to CO₂ by the mixed soil flora in contrast to the benzene or phenol utilizing pure cultures.     

Hämatologische beobachtungen an regenbogenforellen (Salmo gairdneriRich.) VII. Färbeindex (FI), absoluter Hämoglobingehalt des Einzelerytrozyten (HbE) and mittlere Hämoglobinkonzentration des Einzelerythrozyten (MCHC)

180 rainbow trouts (Salmo gairdneriRich.), aged from 1 to 3 years, were examined for fluctuations, caused by age and season, by means of colour index (CI), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC).CI and MCH behave similarly. Both are increasing until the 2nd year and stay relatively constant thereafter. If the gender is not considered — there are no significant differences in the values of males and females — the CI increases from 1,4 in the first year over 1,6 to 1,7 in the age of 3 years, and the MCH increases from 44,4 over 52,6 , 56,8 , 58,1 to 55,5 .A seasonal periodicity of both indices could not be indicated on not-matured animals (F₂) which were two summers of age. Only, the january values appeared increased — CI: 2, MCH: 68,3 — otherwise the CI varies between 1,8 and 1,7 and the MCH between 53,3 and 59,1 .The MCHC-values of the age groups examined vary between 24,4% and 27,3%. The values of the yearlings form an exception (19,8%). These values certainly are inexact and too low because of the small number of individuals checked (3).

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Mit finanzieller Unterstützung durch die DFG.Institut für Siedlungswasserbau und Wassergütewirtschaft der Universitat Stuttgart Fischtoxikologische Arbeitsgruppe     

Hämatologische Beobachtungen an Regenbogenforellen (Salmo gairdneri RICH.). V. Die Erythozytenverteilungskurve

Zusammenfassung Für die Fischpathologie wird als differentialdiagnostisches Verfahren die Erythozytenmessung vorgeschlagen. Zur Darstellung der Erythrozytenverteilungskurve wird wegen der elliptischen Form der Fisch-Erythrozyten die in der Humanmedizin übliche Technik modifiziert.An 102 Regenbogenforellen (Salmo gairdneri) beiderlei Geschlechts im Alter von 1 bis 3 Jahren wurde versucht, die Normalkurve für gesunde Tiere dieser Population zu ermitteln. Die Größenverteilung der Erythrozyten ergibt eine Gauss-Glockenkurve, deren Gipfel in die Größenklasse 30–35 µm²/ fällt, und deren Basis von 15–20 µm²/ bis 55–60 µm²/ reicht.Zwischen den Price-Jones-Kurven der Milchner (52 Individuen) und Rogner (50 Individuen) bestehen keine signifikanten Unterschiede. Ebenso konnte keine Beeinflussung dieser Normalkurve durch unterschiedliches Alter oder jahreszeitliche Einflüsse — untersucht wurden in dieser Hinsicht die F₂ — beobachtet werden.

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Summary As differential-diagnostic feature in the fish pathology it is suggested to measure the red blood cells. The normal technique used in human medicine for plotting the distribution curve of the red blood cells is modified, because the red blood cells of the fish are of elliptical shape.102 rainbow trouts (Salmo gairdneri), both, male and female, and 1–3 years of age, were examined to find the normal curve for healthy animals of this population. The size distribution of the red blood cells show a bell-shaped Gauss-curve, the peak of which is 30–35 µm²/, and the basis of which reaches from 15–20 µm²/ to 55–60 µm²/.The Price-Jones-curves show no significant differences between the milters (52 individuals) and the spawners (50 individuals). Besides, changes caused by different age or seasonal influences could not be observed on this normal curve. Analyzed were the F₂ individuals.

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Institut für Siedlungswasserbau und Wassergütewirtschaft der Universität Stuttgart Biologische Abteilung - Arbeitsgruppe Haider