Alpha- and beta-adrenergic receptors in rat myocardium membranes after prolonged ethanol inhalation

Summary After 3 weeks of continuous ethanol intoxication by inhalation, the maximal number and affinity of the -and -receptors of rat heart were unchanged. These data indicate that adrenergic receptor disturbances are not involved in the mechanism of chronic ethanol-induced triglyceride deposition in the heart.Acknowledgments. This work was supported by grants from the Institut National de la Santé et de la Recherche Médicale. We wish to thank Mr M. Clément for skilled technical assistance in performing chronic ethanol inhalation treatments.     

The dopamine autoreceptor agonist B-HT 920 markedly stimulates sexual behavior in male rats

Summary B-HT 920, a selective agonist at dopamine (DA) autoreceptors, strongly increased the incidence of penile erections (PE) in male rats, an effect which was dose-related and antagonized by haloperidol. B-HT 920 at 100 and 200 g/kg i.p. significantly altered the copulatory pattern of sexually active male rats, reducing the number of mounts and intromissions as well as the latency to the first ejaculation, a stimulant effect which was confirmed in sluggish males at a dose of 100 g/kg.     

Subzelluläre Verteilung der Brenzcatechinamine in Herz und Nebennieren von Meerschweinchen nach Vorbehandlung mitl-α-Methyl-Dopa

Summary -Methyl-noradrenalin synthesized after pretreatment of the guinea-pig with -methyl-dopa was found to be localized, like noradrenalin, mainly in the granular fraction 100 000g of the heart and in the fraction of the chromaffin granules of the suprarenal medulla (15000 g). -Methyl-adrenalin could not bo found.

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Ausgeführt mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Cephalopod myocardial receptors: Pharmacological studies on the isolated heart ofSepia officinalis (L.)

Summary This paper presents a synopsis of the information available about the pharmacological action of various substances on the cephalopod heart, with special emphasis on the central heart ofSepia officinalis. Threshold concentrations, EC₅₀ values and maximum effective concentrations have been experimentally determined. Studies with various transmitter substances, analogous compounds and antagonists have led to the following picture: Acetylcholine is the natural inhibitory transmitter substance; it acts via receptors with nicotinic properties which can be blocked by d-tubocurarine and -bungarotoxin. The probable excitatory transmitter system is represented by a noradrenergic innervation. Noradrenaline has a positive inotropic and a positive chronotropic action on in vitro heart preparations. A positive inotropic response can also be evoked by serotonin (5-HT); this effect is not due to stimulation of the catecholamine receptor, as is shown by cross-over experiments with specific blocking agents. Furthermore, a peptidergic receptor system has been described which reacts with the molluscan cardioactive peptide FMRF amide most effectively. It is assumed that cardioactive peptides may reach the central heart in the circulating blood; the sites of synthesis and release are still unknown. Possibly the NSV-layer of the vena cava is involved in hormonal cardiovascular regulation processes.     

Inhibition of steroidogenic activity in the adrenal cortex of rats fed benzene hexachloride (hexachlorocyclohexane)

Summary Feeding various dosages of benzene hexachloride (100, 250, 750 and 1500 ppm) in the diet to weanling male albino rats for 90 days resulted in marked hypertrophy of the adrenals with large, vacuolated cells in the cortex at 750 and 1500 ppm. Accumulation of cholesterol-positive lipids and marked reduction in the activities of steroidogenic enzymes such as ⁵ 3 HSDH, 11 HSDH, G-6-PDH and SDH were seen using histochemical methods in the adrenal cortex of rats fed 750 and 1500 ppm. The results are suggestive of steroidogenic inhibition at 750 and 1500 ppm of dietary BHC while 100 and 250 ppm did not produce any discernible changes in the adrenal cortex.Acknowledgments. The authors thank Dr Muralidhara, H.P. Ramesh and K. Nanjundiah for their help and Prof. H.B. Devaraj Sarkar, Department of Zoology, University of Mysore, for providing us facilities for histochemical work. We are grateful to Sri C.P. Natarajan, for his keen interest in this investigation.     

Tumor necrosis factor α in the pathogenesis of cerebral malaria

Physiologically in the brain, cytokines such as tumor necrosis factor-alpha (TN) are released by the immune system and can modulate neurological responses. Conversely, the central nervous system (CNS) is also able to modulate cytokine production. In the case of CNS disorders, cytokine release may be modified. Cerebral malaria (CM) is a complication of Plasmodium falciparum infection in humans and is characterized by a reversible encephalopathy with seizures and loss of consciousness. Central clinical signs are partly due to sequestration of parasitized red blood cells in the brain microvasculature due to interactions between parasite proteins and adhesion molecules. TNF is produced and released by host cells following exposure to various malarial antigens. The increase of TNF release is responsible for the overexpression of adhesion molecules. This article reviews the involvement of TNF in cerebral malaria and the relation with all the processes involved in this pathology. It shows that (i) TNF levels are increased in plasma and brain but with no clear correlation between TNF levels and occurrence and severity of CM; (ii) TNF is responsible for intercellular adhesion molecule-1 upregulation in CM, the relation being less clear for other adhesion molecules; (iii) TNF receptors are upregulated in CM, with TNF receptor 2 (TNFR2) showing a higher upregulation than TNFR1 in vivo; (iv) in murine CM, low doses of TNF seem to protect from CM, whereas excess TNF induces CM and anti-TNF therapies (antibodies, pentoxifylline) did not show any efficiency in protection from CM. Moreover, the involvement of lymphotoxin a, which shares with TNF the same receptors with similar affinity, appears to be an interesting target for further investigation.Received 4 December 2002; received after revision 7 February 2003; accepted 14 February 2003     

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.     

Selective protection of cells against X-irradiation. Isoproterenol protects only those cells that possesβ-adrenoreceptors

Summary In mixed culture of Chinese hamster fibroblatst, clone 431, and transformed murine L fibroblasts, clone B-82, isoproterenol was found to protect only 431 cells against ionizing radiation. It was shown that 431 cells, in contrast to B-82 cells, possess-adrenoreceptors, and the radioprotective effect of isoproterenol can be realized only if this agent interacts with-adrenoreceptors coupled with the cAMP system. Since malignization often causes the disappearance of-adrenergic and other hormone receptors, the combined culturing and irradiation of the cells studied can be regarded as a model of the growth of malignant cells (B-82) among normal tissue cells (431 cells) under conditions of radiation therapy. A possibility of selective protection against radiation damage of normal tissue cells, with retention of the former radiosensitivity of tumor cells, is discussed.     

Effect of dibutyryl cyclic AMP and analogs on the rate of contractions of myocytes in culture

Summary ²O,⁶N-butyryl, 3, 5-cyclic monophosphate (dibu cAMP) when added to fetal rat heart cells in culture inhibits myocyte contraction. This inhibition is 100, 84 and 51% complete when the dibu cAMP concentration used is 2, 0.2 and 0.02 mM, respectively. The potency of dibu cAMP derivatives in myocyte contraction inhibition follows the order, dibu cAMP> ⁶N-bu cAMP> ²O-bu cAMP=AMP>butyrate. The inhibition caused by the first three chemicals is greater than 70%.The author was a Moss Heart Fellow and acknowledges the technical assistance of Ms Martha Peet. This work was supported in part by the American Heart Association, National Science Foundation and American Cancer Society.     

Bobierrit-Newberyit-Konkremente in den Drüsensäckchen des Vormagens vonLama lama

Summary The formation of Bobierrite/Newberyiteconcrements may occur in the glandular saccules of the llama (Lama lama) forestomach, if the motility of abomasal compartments is disturbed and these saccules are not able to evert at periodic intervals.     

A tissue-selective prostaglandin E2 analog with potent antifertility effects

Summary N-methanesulfonyl 16-phenoxy--tetranor PGE₂ is a prostaglandin analog which is markedly more tissue selective than PGE₂. This compound is 10–30 times more potent than PGE₂ in animal models which are considered relevant to antifertility effects in humans. In pharmacological tests which are believed to be predictive for side effects in humans, the compound has potency either equal to or less than that of PGE₂.     

Influences of temperature change on the relaxation and amplitude inhibition by noradrenaline in the rabbit jejunum

Summary In the rabbit jejunum, the elevation of temperature within the range of 25–37°C diminished the sensitivity to noradrenaline (NA) for both the relaxation and amplitude inhibition. The relaxation by NA was mainly mediated via adrenergic -receptors at 25, 30 or 37°C. The amplitude inhibition was mediated via -receptors at 37°C, and both - and -receptors at 30 or 25°C.     

Studies onxHaynaldoticum sardoum Meletti et Onnis metabolism during seed life-span: α-amylase and glutamate decarboxylase activity

Summary Embryo GAD activity and -amylase in the endosperm of 2 different physiological lines (CP; CV) ofxHaynaldoticum sardoum Meletti et Onnis were evaluated and different stages of seed ripening and progressively older seeds were examined. Results concerning GAD activity during ripening show differences between CP and CV seeds, the former being more active. In the ageing seeds, the GAD remains constant (CP is twice as much as CV) up to 4th year and greatly decreases at the 5th. The -amylase activity is fairly constant during ripening in CV endosperm and increases in CP: at the fully-ripe stage, both show similar values. During seed ageing, the activity decreases progressively in CV endosperm while, in CP, values are greater but fairly constant. The results are discussed in connection with dormancy and the different physiological ageing of seeds.This work was supported by a grant from the Consiglio Nazionale delle Ricerche (Rome, Italy).Acknowledgments. The authors wish to thank Mr F. Saviozzi, Mr V. Sbrana and Mr R. Bertini for their expert technical assistance.     

“The True” in Gottlob Frege's “Über die Grundlagen der Geometrie”

In this essay, I examine the metaphysical and metalogical ramifications of Gottlob Frege's controversy with David Hilbert and Alwin Korselt, over Hilbert's Grundlagen der Geometrie. These ramifications include(1) Korselt's original appeals to general metatheoretic Deutungen (interpretations);(2) Hilbert's puzzling belief that whatever is consistent in some sense exists; and(3) Frege's semantic monist conviction that theoretical sense and reference (mathematical and other) must be eindeutig lösbar (uniquely solvable).My principal conclusions are(4) that Frege's position in (3) represented a pervasively dogmatic presumption that his newly discovered quantification theory must have a propositional metatheory (the True; the False); and(5) that this needless assumption adversely affected not only his polemic against the moderate semantic relativism of Hilbert and Korselt, but also his reception of type-theoretic ideas, and greatly facilitated his vulnerability to the sort of self-referential inconsistency Russell discovered in Grundgesetz V.These conclusions also seem to me to provide a conceptual framework for several of Frege's other arguments and reactions which might seem more particular and disparate. These include(6) his arbitrary restrictions on the range of second-order quantification, which undercut his own tentative attempts to give accounts of independence and semantic consequence;(7) his uncharacteristic hesitation, even dismay, at the prospect that such accounts might eventuate in a genuinely quantificational metamathematics, whose Gegenstände (objects) might themselves be Gedanken (thoughts); and, perhaps most revealingly(8) his otherwise quite enigmatic, quasi-stoic doctrine that genuine formal deduction must be from premises that are true.A deep reluctance to pluralize or iterate the transition from theory to meta-theory would also be consonant, of course, with Frege's vigorous insistence that there can be only one level each of linguistic Begriffe (concepts) and Gegenstände (objects). With hindsight, such an assumption may seem more gratuitous in the philosophy of language (where it contributed, I would argue, to Wittgenstein's famous transition to the mystical in 6.45 and 6.522 of the Tractatus); but its more implausible implications in this wider context seemed to emerge more slowly.In the mathematical test-case discussed here, however, such strains were immediately and painfully apparent; the first models of hyperbolic geometry were described some thirty years before Frege drafted his polemic against Hilbert's pioneering exposition. It is my hope that a careful study of Frege's lines of argument in this relatively straightforward mathematical controversy may suggest other, parallel approaches to the richer and more ambiguous problems of his philosophy of language.Niemand kann zwei Herren dienen. Man kann nicht der Wahrheit dienen und der Unwahrheit. Wenn die euklidische Geometrie wahr ist, so ist die nichteuklidische Geometrie falsch, und wenn die nichteuklidische wahr ist, so ist die euklidische Geometrie falsch.No one can serve two masters. One cannot serve truth and untruth. If Euclidean geometry is true, non-Euclidean geometry is false, and if non-Euclidean [geometry] is true, Euclidean geometry is false. Über Euklidische Geometrie [Frege 1969], p. 183.     

Effects of pregnancy on the glucose-induced insulin release from cultivated pancreatic islets of the rat

Summary 7-day-cultured islets from pregnant Wistar rats released at 5.6 mM glucose significantly more insulin than islets from nonpregnant rats, whereas in vivo this heigthened glucose sensitivity is lost 48 h post partum.Investigations carried out as a part of the Forschungsprojekt Diabetes mellitus und Fettstoffwechselstörungen supported by the Ministry of Health of German Democratic Republic.     

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.     

Concerning the anchoring of acetylcholinesterase in biomembranes

Summary Highly purified acetylcholinesterases from various sources do not contain hydroxyproline and hydroxylysine, indicating the absence of a collagenlike tail. The enzymes examined are therefore bound to the membrane in a different way compared with acetylcholinesterase isolated from electric organ.     

Über die Zytologie der Parthenogenese und der Geschlechtsbestimmung bei der GallmückeOligarces paradoxus Mein

Summary InOligarces paradoxus, the chromosomal behaviour was compared during pedogenetic development of and . The -egg undergoes a single non-reductional maturation division, the -egg shows two divisions which result in reduced nuclei. After maturation in the -egg, the number of chromosomes is restored by endomitosis. The nuclei of germ-line cells contain a high number of chromosomes (: 74\2-82; : at least 58) in both sexes. In somatic nuclei, the number is diminished by elimination to 10 in , to 5 in .     

Alteration of early T lymphocyte count in patients with herpes genitalis

Summary Peripheral blood samples from 52 women, including 16 with herpes genitalis and 36 healthy persons, were studied to enumerate subpopulations of lymphocytes. It was found that the mean percentage of active T lymphocytes was significantly less in the patients with herpes genitalis than in the controls.Acknowledgment. This work was done at the Department of Obstetrics and Gynecology, Kansai Medical University and the authors are indebted to Professor I. Sawaragi for his support and encouragement. We also express our thanks to Dr James Monthony, Bio Rad Laboratories for his generous donation of immunobeads for this study.     

Metabolic biochemistry and the making of a mesopelagic mammal

Large seals such as northern and southern elephant seals and Weddell seals are able to dive for startling duration and enormous depth. The current dive duration record is 120 minutes (recorded for the southern elephant seal); the current depth record is 1.5 km (recorded for the northern elephant seal). Equally striking is the widespread observation that these seals when at sea spend close to 90% of the time submerged and often at great depth. For practical purposes, these species can be viewed as true mesopelagic animals when they are at sea. A review of current knowledge indicates that low power output but high efficiency metabolic functions of skeletal muscles coupled with inherently low (and potentially further suppressible) metabolic rates constitute strategic biochemical components in the making of a mesopelagic mammal.