Interaction of atropine or methylatropinium with four effects of two cholinergic drugs.

In mice, pilocarpine - or oxotremorine - induced decrease in locomotor activity and increase of the reaction time to pain were antagonized by atropine and not by methylatropinium. Identical doses of atropine and methylatropinium suppressed the antagonism of the cholinergics towards reserpine-induced palpebral ptosis. Cholinergics-induced hypothermia was not clearly antagonized by atropine or methylatropinium.     

Relaxation of isolated rabbit veins mediated by latent histamine H2-receptors

Summary Isolated rabbit veins preconstricted by either norepinephrine, methoxamine or potassium were relaxed by histamine in the presence of mepyramine, a histamine H₁-antagonist. The relaxation was not antagonized by atropine, propranolol and indomethacin but by an H₂-antagonist cimetidine. It is likely that histamine relaxes the rabbit veins through H₂-receptors.     

Wirkungsverstärkung von Adrenalin und Noradrenalin durch Azetylcholin am isolierten Irisdilatator des Kaninchens

Summary Radial strips of the isolated iris of rabbits were suspended in streaming Tyrode's solution and their contractions were registered isometrically. The contractions produced by adrenaline or noradrenaline were increased after the administration of eserine or neostigmine. Acetylcholine in a concentration 5.10^–7–5.10^–6 M enhanced the effect of adrenaline and noradrenaline on both, the normal and the chronically denervated dilator muscle. Acetylcholine did not enhance the contractions by adrenaline and noradrenaline in the presence of atropine. Choline in a concentration of 5.10^–6 M had no effect whereas concentrations of 5.10^–5 M were slightly effective.     

Effect of acetylcholine on melanophores ofRana tigrina

Summary Acetylcholine produced melanin aggregation and blanching of skin colour inRana tigrina, the common Indian frog. The effects were more prolonged in frogs pretreated with an anticholinesterase agent. Acetylcholine effects were not antagonized by eitherm-cholinolytic (atropine) orn-cholinolytic (pentolinium) agents, but were markedly inhibited by procaine. The results have been discussed in the light of the well-known membrane-stabilizing effect of procaine.     

Hypoxic tachycardia in the rat

Summary Awake, freely breathing rats subjected to moderate hypoxia (10% O₂) manifest prompt tachycardia which is essentially unaffected by atropine and is blocked by propranolol, and is thus apparently mainly of sympathetic origin.This work was supported by grants from American Heart Association — Greater Los Angeles Affiliate (437IG), and National Science Foundation (GB-41390). J. D. L. was a Summer Scholar selected by the Committee for Advance Science Training. We thank Mr D. Ward and Miss L. J. Berg for much valuable assistance and Dr. J. L. Kinney for help in the statistical analysis of the data.     

Essais d'inhibition de l'action inflammatoire cutanée du chloroforme chez le rat

Summary (1)—In the rat, total extracts of cortex, cortisone and A.C.T.H. do not retard the fixation of a vital colorant at the level of a cutaneous zone irritated by chloroform.(2)—Phenergan prolongs the delay in the appearance of the blue.(3)—Sodium salicylate selectively inhibits the inflammatory cutaneous action of chloroform, even after adrenalectomy.     

The effect of lactose and iron on strontium absorption

Summary In rats fed on a milk diet with or without the addition of lactose and/or iron the transileal strontium-85 transfer was higher by 14–38% and the intestinal strontium retention lower by 6–23% than in control rats fed on standard laboratory food.Presented, in part, at the 12th Yugoslav Symposium for Radiation Protection, Ohrid 1983, and at the 11th Regional Congress of IRPA (Austrian — Hungarian — Yugoslav Radiation Protection Meeting), Wien 1983. Acknowledgments. This work was supported by a research grant from the Scientific Research Council of the Socialist Republic of Croatia. The author thanks Mrs M. Buben for her technical assistance.     

Untersuchungen über den Wirkungsmechanismus von Procarbazin (Natulan®)

Summary The cytotoxic methylhydrazine derivative procarbazine or Natulan® has a marked influence on the synthesis of deoxyribonucleic acid in Ehrlich ascites carcinoma cells. The incorporation of³H-thymidine into DNA — measured by autoradiographic methods — is inhibited.     

Hensen's node — The ’Organizer’ of the amniote embryo

Conclusion If the hundred years of study on theHensen's node — i.e. on gastrulation and early determination of the embryos of amniote vertebrates — teach anything, they teach in the first place how limited and fragmentary our knowledge is about one of the most central problems of the whole developmental biology. We know that the events in early amniote development — or early avian development, on which our data and ideas are nearly all based — in many ways resemble those in early Amphibian development, which is only slightly better understood, but we also know that direct extrapolations from anamniotes to amniotes cannot be made without proper reservations and without studying the amniote embryos themselves. And we have practically no idea of what is really going on in the cells of the blastoderm when they move, invaginate, induce or are induced, interact, become determined and begin their differentiation. We know that at the stages of gastrulation, the node, and indeed the whole blastoderm, is in a very labile state and can be regulated in many ways to produce a harmonious whole — or a monster — although we only understand very poorly the modes of this regulation. The progress made during the decades, and particularly in recent years, shows, however, that useful information is accumulating to produce a coherent picture, and there is no reason to be pessimistic.Dedicated to ProfessorEtienne Wolff on the occasion of his retirement.     

Photobiochemistry without light

Summary Efficient excited state formation — much higher than that hitherto expected — may occur in organelles and in intact cells. Excited triplet states can be enzymatically generated in high yields by different routes. An example is the oxidation of isobutanal to acetone and formic acid, catalyzed by horseradish peroxidase. Other enzymatic systems that generate triplet carbonyls are linear aliphatic aldehydes when oxidized by peroxidase/O₂, or the indole-3-acetic acid/peroxidase/O₂-reaction. The latter is widespread in plants.This new field — photobiochemistry without light — has led to a growing awareness of the idea that cells may utilize excited states to trigger photochemical processes even in the dark. Such phenomena are of considerable importance, also for the understanding of weak photon emission from biological systems.     

Picrotoxin-diazepam interaction in a behavioural schedule of differential reinforcement of low rates

Summary In rats working in a behavioural schedule of differential reinforcement of low rates (6 or 10 sec), picrotoxin (1 mg kg^–1) decreased the number of premature responses and increased (in DRL 10 sec only) the number of rewarded responses. The effect of picrotoxin was antagonized by diazepam (2 mg kg^–1). In contrast to picrotoxin, strychnine (1.5 mg kg^–1) increased the number of premature responses.This work was supported by a grant of I.N.S.E.R.M. (ATP 39-76-71).     

Immunochemical identification of vitellogenin in the serum of the newtTriturus cristatus

Summary The hematic yolk precursor — vitellogenin — has been identified immunochemically in the serum of estrogenized females of the newtTriturus cristatus by employing an antiserum prepared against yolk proteins.     

The literature and the science of ‘two cultures’ historiography

This paper discusses the historiography of the ‘two cultures’ controversy. C. P. Snow’s lament about the ‘two cultures’, literary and scientific, has inspired a wide range of comment—much of which begins by citing Snow and his thesis, before going on to discuss very different things. This paper focuses upon one strand of this commentary, the historical analysis of the controversy itself. A ‘historical’ analysis is defined here as one that resists the impulse to enter the argument on behalf of Snow or Leavis, to conceive of their argument in the terms that Snow defined, or to invoke their argument as a precursor to some contemporary issue. Instead, a historical interpretation registers distance between that day and this, takes the controversy itself as its object of study, and explores the tensions and associations that came to be packed into those now familiar terms. As the fiftieth anniversary of Snow’s Rede Lecture nears, this approach—rather than the repetition of clichés about the bridging of cultures—offers both analytical perspective on the controversy and interpretive possibilities for its examination.     

Thomas Reid and the problem of induction: from common experience to common sense

By the middle of the eighteenth century the new science had challenged the intellectual primacy of common experience in favor of recondite, expert and even counter-intuitive knowledge increasingly mediated by specialized instruments. Meanwhile modern philosophy had also problematized the perceptions of common experience — in the case of David Hume this included our perception of causal relations in nature, a fundamental precondition of scientific endeavor.In this article I argue that, in responding to the ‘problem of induction’ as advanced by Hume, Reid reformulated Aristotelian foundationalism in distinctly modern terms. An educator and mathematician self-consciously working within the framework of the new science, Reid articulated a philosophical foundation for natural knowledge anchored in the human constitution and in processes of adjudication in an emerging modern public sphere of enlightened discourse. Reid thereby transformed one of the bases of Aristotelian science — common experience — into a philosophically and socially justified notion of ‘common sense’. Reid's intellectual concerns had as much to do with the philosophy of science as they did with moral philosophy or epistemology proper, and were bound up with wider social and scientific changes taking place in the early modern period.     

Structures and molecules involved in generation and regulation of biological rhythms in vertebrates and invertebrates

Melatonin from the retina and the pineal gland functions in neuroendocrine hierarchies. Photoreceptors — eyes and extraretinal — detect light. Oscillators — pineal and suprachiasmatic nuclei — act as pacemakers. Driven neuroendocrine rhythms carry temporal hormone signals throughout the body. Light controls melatonin: light sets the phase of the melatonin rhythm and determines the duration of melatonin synthesis. By these means, circadian rhythms (e.g. in locomotor activity and body temperature) and seasonal rhythms (e.g. in reproduction) are controlled.     

Cholinesterase reactivators — Contribution to the study of their metabolic effects

Summary Cholinesterase reactivators — trimedoxim, methoxim and obidoxim — injected in the dose of 20 mg/kg s.c., increase muscle glycogen concentration in normal, but not in adrenalectomized rats. This effect may be in connection with simoultaneously found rise of serum corticosteron level. Trimedoxim decreases adrenaline, methoxim and obidoxim noradrenaline concentration in adrenals.     

Hochenergiephysik

Summary Short Review of the actual state of High Energy Physics: Cosmic ray research — Accelerators for high energy particles — Instruments for detection of fast particles — Classification of elementary particles.     

Morphological evidence for axonal transport of glycogen in neurons innervating cutaneous receptors inLacerta sicula (Squamata: Reptilia)

Summary Three types of glycogen-containing cutaneous nerve terminals — two of them hitherto unknown — are described. It is shown that the glycogen is synthesized in the perikaryon and transferred to the terminals by means of slow axoplasmic transport.     

Rehabilitating theory: refusal of the ‘bottom-up’ construction of scientific phenomena

In this paper I inquire into Bogen and Woodward’s (1988) data/phenomena distinction, which in a similar way to Cartwright’s construal of the model of superconductivity (1995)—although in a different domain—argues for a ‘bottom-up’ construction of phenomena from data without the involvement of theory. I criticise Bogen and Woodward’s account by analysing their melting point of lead example in depth, which is usually cited in the literature to illustrate the data/phenomenon distinction. Yet, the main focus of this paper lies on Matthias Kaiser’s (1995) case study of the plate tectonic revolution, the most extensive case study that has been put forth to support the bottom-up construction of phenomena. On the basis of new historical evidence, which has been overlooked not only by Kaiser but also by the entire historical literature on the plate tectonic revolution, I demonstrate that phenomena are not constructed from the bottom-up but rather, admittedly counter-intuitively, from the top-down.     

Age and evolution of bacteria

Summary Age and evolution of bacteria can be estimated, including facts and hypotheses belonging to morphology, biochemistry, paleontology, ecology and pathogenicity. The corresponding dates are summarized in the following.About 3.5×10⁹ years: Origin of heterotrophic eobiontes.—About 3.0×10⁹ years: The increasing lack of prebiogenic substances is due to the evolution of the respiratory pathway, that is due to the evolution of the photoautotrophy and now released O₂ is due to the evolution of strictly aerobic cells. There is, simultaneously, a transition of spheres to long forms, development of an amoebalike motility, the evolution of spirochetes and the substitution of cholesterol for cardiolipin in the more evolved cells (i.e. strictly aerobic cells etc.).—About 2.0×1.0×10⁹ years: Evolution of the eucyte by symbiosis of a great, primitive, anaerobic, cholesterol-containing cell with a little, strictly aerobic, cardiolipin-containing cell, with a spirochete and in some extent also with photoautotrophic cell.—About 1.0×10⁹ years (maximum: 1.8–1.5×10⁹ years, minimum: 7×10⁸ years): Evolution of metazoa and begin of cell differentiation.—About 2.0–1.0×10⁹ years: Evolution of the bacterial murein sacculus and then development of flagella mediated motility.—About 6×10⁸ years (maximum:1.0×10⁹ years, minimum: 4.5×10⁸ years): Evolution of the gram-negative cell wall.—About 4.0×10⁸ years: Evolution of the gram-positive cell wall.—About 5.0×10⁸ years: Gram-negative, strictly anaerobic bacteria become the first enteric bacteria in coelenterates. About 4.0×10⁸ years: gram-negative, microaerophilic bacteria become Enterobacteriaceae in vertebrates in addition to the strictly anaerobic organisms.—About 3.0–2.0×10⁸ years: Consolidation of the Salmonella in reptiles.—About 2.0–1.5×10⁸ years: Consolidation of Escherichia and other coliform species in mammals.—About 10⁶ years: Evolution of typically human pathogenic organisms, transmitted in homogeneous-homonomous infection ways, i.e. N. gonorrhoeae, S. typhi, T. pallidum, etc.Dedicated to Prof. H. Habs, Bonn, to his 75th anniversary on 11 September 1977.Acknowledgment. I thank Prof. F. Müller, Hamburg, and Prof. P. Sitte, Freiburg i. Br., for stimulating discussions.