A historical review of the problem of mitogenetic radiation

Summary The miracle of caryokinesis was the starting point that stimulated Alexander G. Gurwitsch to carry out his famous mitogenetic experiments in 1923. The results obtained confirmed his hypothesis of a weak radiation from cells, which is able to trigger the growth of other cells. Extensive experimental work within the first two decades after this discovery indicated that the problem of mitogenetic radiations is generally related to the biological significance of UV-radiation. Both energetic and informational aspects have to be considered, namely radiation effective in activating molecules, and that involved in arranging them into larger units.The molecular organization of biological structures is evidently governed by nonequilibrium conditions needing the uptake or emission of radiation. These concepts of A. G. Gurwitsch can be linked with modern approaches based on hypotheses of coherence in biology, synergetics and dissipative structures. However, the question of causal interrelationships between this part of non-equilibrium radiation and biological matter on different levels of evolution has to be solved now.     

Changes in mouse liver superoxide dismutase activity and lipid peroxidation during embryonic and postpartum development

Summary In inbred mice possessing high and low tissue superoxide dismutase (SOD) activity, it was observed that the difference in the SOD activities of the liver homogenates during development attains the maximum characteristic of the strain by about the 150th day. Subsequently, the SOD activity change displays a tendency in contrast with the age and the basic state. In the course of the development, a difference was also observed between the 2 mouse strains in the lipid peroxidation variation.Part XVIII of the series Properties of enzymes.     

Limitations of the ‘direct linear plot’ in evaluation of drug-protein binding parameters

Summary The applicability of the direct linear plot is compared with that of the Scatchard plot for the estimation of protein binding parameters. Only, if one class of binding sites exists in the system tested, binding parameters may be estimated by use of the direct linear plot. On the other hand the Scatchard plot also provides estimates in systems with more that one class of binding sites.     

Structural differences of cone ‘oil-droplets’ in the light and dark adapted retina ofPoecilia reticulata P.

Summary The vast majority of oil-droplets in the dark and light-adapted retinal twin-cones ofPoecilia reticulata is of the matrix-type. In bright light (day light+overhead strip light) there occurs in some regions a very pronounced numerical change from matrix to cristate-type, whereas other regions remain unaffected. The functional significance of these differences is discussed.     

The effect of chloramphenicol analogs on protein biosynthesis in a cell-freeEscherichia coli B system

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Laboratory of Biological Investigations.

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Laboratory for Chemistry of Antibiotics.     

Some functional characteristics of the electroreceptors (the ampullae of lorenzini) of elasmobranchs

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Correlations between glucose-inhibition and control parameters of α-glucosidase kinetics inApis mellifica haemolymph (Hymenoptera: Insecta)

Summary Kinetics studies of haemolymph -glucosidase inhibition by D. glucose led to general correlations between inhibition and control parameters, all over the honeybee development. Maximum velocities are not affected by the inhibition, while affinity constants are always significantly increased, and Hill coefficients tend to decrease, especially in foraging adults and in prenymphs. In this later case, the n-type effect tends to break the manifestation of the K-type mechanism.     

Real-time models of morphogenetic processes

Summary Morphological transformations are often describable by simple series kinetic models,AB, ABC, etc., which allow assessment of the rates of interconversion of the distinguishable shapes or forms present and their probabilities of occurrence at various points in time, thus providing a means for kinetic comparisons with biochemical measurements of the molecular-level reactions that cause the transformations. When changes in cell morphology are followed turbidimetrically, the real-time progress curves can be simulated by fitting the data to a form of Beer's law for scattering by mixtures in which the species concentrations change with time in accordance with the chosen kinetic scheme. Because many even relatively large cells are mostly water, classical light scattering theory can be used to interpret the turbidimetric data in terms of simple geometrical models ofaverage cell size and shape suggested by microscopic examination. Two examples are briefly considered, the stimulus-induced changes in blood platelet shape and apparent size and their correlation with cytosolic-free calcium, and apparent swimming motion exhibited by neutrophils in suspension.What do you know about this business? the King said to Alice. Nothing, said Alice. Nothing whatever? persisted the King. Nothing whatever, said Alice. That's very important, the King said. Lewis Carroll (1865), in Alice's Adventures in Wonderland     

Suppression of antibody formation against sendai virus in the SV40 and adenovirus 16 infected hamsters

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Paul Ehrenfest on the Necessity of Quanta (1911): Discontinuity,Quantization, Corpuscularity,and Adiabatic Invariance

Our object in this paper is to study the antecedents, contents, implications, and impact of a not well-known or appreciated paper by EHRENFEST in 1911 on the essential nature of the different quantum hypotheses in radiation theory. After a careful analysis of EHRENFESTs notebooks, correspondence, and publications, we conclude that the essential points of EHRENFESTs paper were not perceived to a large extent, and hence that its implications were not considered thoroughly. Specifically, we show that EHRENFEST contributed significantly to the clarifications of the differences between PLANCKs and EINSTEINs respective quantum hypotheses, as well as to those of the concepts discontinuity, quantization, and corpuscularity.     

Suppression of delayed type hypersensitivity of mice by lead

Summary Application of lead suppressed the delayed type hypersensitivity (DTH) of mice induced by sheep red blood cells (SRBC). Inhibition of elicitation of DTH in primary as well as in secondary response was correlated with the concentration of lead in the blood of the mice.Acknowledgments. Supported by the Georg-und-Agnes-Blumenthal-Stiftung and the Verein für Wasser-, Boden- und Lufthygiene. We thank Miss Schachtschneider for the excellent technical assistance.     

On the host-symbiont-cycle of a leafhopper (Euscelis plebejus) endosymbiosis

Summary In the host-symbiont-cycle ofEuscelis plebejus and its bacterial symbionts each of both symbionts (a and t) appears in an infection form during the intraovarial transmission (adult female) as well as during the entrance into the mycetocytes (embryo) and in a vegetative form during the remaining time of the cycle.This work was supported in part by a grant from the Deutsche Forschungsgemeinschaft to ProfessorK. Sander, whom I thank for helpful discussions.     

X-ray research for polycrystals. The formation geometry of instrumental width of the diffractional line at the investigation of the polycrystals in the translucent X-rays

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Funktion der Spermien in inkompatiblen Kreuzungen der StechmückeCulex pipiens L.

Summary After irradiating males of the incompatible crossC. pipiens Hamburg ×C. pipiens Paris with X-ray doses between 1 kR and 40 kR, it could be shown that in this cross the sperm has only the function of activating the egg. All the hybrid embryos develop from the haploid female pronucleus.Herrn Professor Dr.H. Laven danke ich für Unterstützung und wertvolle Diskussionen.     

Über die PAS-Glykogen-Reaktion im Bereich der Ringbinden beiAmblystoma mexicanum Cope

Summary Glycogen substance, detected by the PAS-reaction in the so-called Ringbinden of the trunk musculature from the larval form ofAmblystoma mexicanum Cope, is described. The PAS-glycogen reaction in the myofibril complex of the common Ringbinde does not differ from that found in the normal one.     

Copper acetate as an accelerator in mouse skin carcinogenesis by 9,10-dimethyl-1,2-benzanthracene

Résumé Une solution de l'oxyacétate de cuivre n'est pas cancérigène pour la peau de la souris blanche. L'acétate n'est ni un initiator ni un promoter pour la cancérisation par 9,10-diméthyl-1,2-benzanthracène. Cependant, le traitement des animaux avec l'acétate pendant 10 semaines puis avec l'hydrocarbure augmente la production des tumeurs.     

The nutritional incidence of flavonoids: some physiological and metabolic considerations

Summary Examination of the physiological activity of flavonoids in relation to their antiscorbutic properties shows that some of these compounds, the flavan-3=ols, have a particular nutritional impact and consequently should be distinguished from the rest of the flavonoids and polyphenolds. Therefore, the use of the term Vitamin P and Bioflavonoids is also discussed.     

Independent responses of two fruit characters to developmental regulation inMicroseris douglasii (Asteraceae,Lactuceae)

Summary The hairy achenes and yellow achenes characters are expressed only in peripheral fruits onMicroseris capitula. Segregation in interstrain hybrid D37 shows that the genes responsible for these characters respond independently to developmental regulation.Supported by grants Ba 536/7-7 from the Deutsche Forschungsgemeinschaft, and DEB 80-09427 from the National Science Foundation.     

A new synthesis of dehydromunduserone

Zusammenfassung Eine einfache Synthese von Dehydromunduseron aus 7,2,4,5-Tetramethoxy-isoflavon wird beschrieben.