Piroxicam-induced analgesia: Evidence for a central component which is not opioid mediated

Piroxicam is a nonsteroidal anti-inflammatory drug with a potent analgesic effect. In order to establish whether the analgesic action of Piroxicam has a central component, we studied the effect of the drug on the nociceptive orbicularis oculi reflexes evoked by electrical stimulation of the cornea and supraorbital nerve in healthy subjects. Piroxicam significantly suppressed the corneal reflex and R3 component of the blink reflex by 28% (p<0.05) and 50% (p<0.01), respectively. This effect was not reversed by the i.v. injection of naloxone. Beta-endorphin levels did not change. Piroxicam administration induces distinct inhibitory changes in nociceptive reflexes, which suggests that the analgesic action of the drug has a central component. The ineffectiveness of naloxone, and the lack of beta-endorphin changes, indicate that this central action is independent of the opioid system; other pain regulatory systems are probably involved.     

Piroxicam-induced analgesia: evidence for a central component which is not opioid mediated.

Piroxicam is a nonsteroidal anti-inflammatory drug with a potent analgesic effect. In order to establish whether the analgesic action of Piroxicam has a central component, we studied the effect of the drug on the nociceptive orbicularis oculi reflexes evoked by electrical stimulation of the cornea and supraorbital nerve in healthy subjects. Piroxicam significantly suppressed the corneal reflex and R3 component of the blink reflex by 28% (p < 0.05) and 50% (p < 0.01), respectively. This effect was not reversed by the i.v. injection of naloxone. Beta-endorphin levels did not change. Piroxicam administration induces distinct inhibitory changes in nociceptive reflexes, which suggests that the analgesic action of the drug has a central component. The ineffectiveness of naloxone, and the lack of beta-endorphin changes, indicate that this central action is independent of the opioid system; other pain regulatory systems are probably involved.     

Some properties of external NADH oxidation by human placental mitochondria

Summary Isolated human term placenta mitochondria catalyse oxidation of external NADH in the presence of cytochrome c. This reaction is insensitive to the respiratory chain inhibitors such as rotenone and antimycin A, and is not coupled to phosphorylation. Comparison of the effect of Mg⁺⁺ ion on NADH plus cytochrome c oxidation by human term placental, human skeletal muscle and rat skeletal mitochondria showed that Mg⁺⁺ ion exerts an inhibitory effect in the case of human mitochondria and a stimulatory effect in the case of rat skeletal muscle mitochondria.This work has been supported by a grant from Ministry of Higher Education Science and Technology within the project No. 01.02.     

Modifications ultrastructurelles provoquées par quelques médicaments sur les terminaisons nerveuses adrénergiques et sur la médullaire surrénale

Summary It has been shown that reserpine and guanethidine deplete granules containing catecholamine in sympathetic nerve endings of both the pineal gland and the vas deferens. This effect is blocked by iproniazid. Bretylium is not able to deplete these granules but it modifies their aspect. It has also been observed that granules of the adrenal medulla are depleted less easily than those of sympathetic nerve endings.     

Toxic effects of boric acid on the German cockroach

Boric acid is a slow-acting, inorganic insecticide whose mode of action has not been satisfactorily elucidated. Reported here is evidence which shows that ingested boric acid destroys the cellular lining of the foregut of German cockroaches,Blattella germanica (L.). This effect appears to be sufficient to bring about the death of the insects, perhaps ultimately by starvation. This finding is important because resistance to conventional insectivides may re-establish boric acid as a prominent cockroach control chemical.     

Colchicine inhibition of ADH effect on frog skin permeability

Summary ADH and AMPc enhance both thiourea unidirectional fluxes in frog skin. This effect is completely abolished by colchicine pretreatment. The ADH increase of thiourea discharge with or without colchicine led us to suppose that colchicine does not directly affect ADH action on outer membrane permeability, but exerts its effects on a site which is limiting for the ADH action on transepithelial permeability.The present work has been supported by C.N.R., Rome.     

Ecdysis inhibition inAcrolepiopsis assectella larvae by digitonin: antagonistic effects of cholesterol

Summary Digitonin has a toxic effect onAcrolepiopsis assectella, inhibiting development and molting of young larvae fed on a semi-synthetic diet. This effect depends on concentration. It does not occur when cholesterol is added to the diet.Acknowledgment. We thank Mme Annie Heinzmann for technical assistance.     

The influence of a new antitumor agent on hemopoietic colony forming cells

The cytostatic and immunsuppressive agent N'-methyl-N'-beta-chloroethylbenzaldehyde hydrazone (B1) in in-vitro experiments has a stimulating effect on colony-forming culture (CFUc) of bone marrow from C57BL mice. This unusual behaviour, which is in contrast to other cytostatics, could also be observed in vitro with CFUc obtained from mice treated with therapeutic doses of B1 for 2 weeks. This stimulation is not a particular effect of B1 alone but seems to depend on a synergistic effect of the combination of B1 and the colony-stimulating activity (CSA) present in the serum from endotoxin-treated mice (MP) in the testing system. The results suggest that the described effect of B1 is due to an interference at the cell membrane of CFUc or their precursor cells.     

Function,persistence, and selection: Generalizing the selected-effect account of function adequately

The selected effect account is regarded by many as one of the most attractive accounts of function. This account assumes that the function of a trait is what it has been selected for. Recently, it has been generalized by Justin Garson to include cases in which selection is understood as a simple sorting process, i.e., a selection process between entities that do not reproduce. However, once extended, this generalized selected effect account seems to ascribe functions to entities for which it looks unintuitive to do so. For instance, the hardness of rocks on a beach being differentially eroded by waves would be ascribed the function of resisting erosion. Garson provides one central argument why, despite appearance, one should not ascribe functions in cases of such sorting processes. In this paper, I start by presenting his argument, which hinges on whether a collection of entities form a population. I find it wanting. I argue instead that some selection processes are evolutionarily more or less interesting and that when a selection process is regarded as evolutionarily uninteresting, it will yield an uninteresting form of function rather than a reason for withholding the concept of function altogether.     

Zur Wirkung von Oxytocin auf einen autorhythmischen glatten Gefässmuskel

Summary The influence of oxytocine on the spontaneously contractile portal vein of the rat has been investigated. This octapeptide decreases the active tension and abolished it completely at a concentration of 5×10^–7g/ml. The effect is not caused by an adrenergic mechanism but by a direct action on the smooth muscle cell.     

EP2 receptor stimulation promotes calcium responses in astrocytes via activation of the adenylyl cyclase pathway

Astrocytes are a heterogeneous population of cells that are endowed with a great variety of receptors for neurotransmitters and neuromodulators. Recently prostaglandin E₂ has attracted great interest since it is not only released by astrocytes but also activates receptors coupled to either phospholipase C or adenylyl cyclase. We report that EP₂ receptor stimulation triggers cAMP production but also causes release of Ca²⁺ from intracellular stores. This effect is shared by other receptors similarly coupled to adenylyl cyclase and elicited by direct stimulation of the enzyme or application of cAMP analogues. However, the stimulation of the Ca²⁺ response by cAMP is not mediated by protein kinase A, since a specific antagonist of this kinase had no effect. Such a cross-talk between cAMP and Ca²⁺ was not observed in all astrocytes. It might therefore reflect a specific resource of either a subpopulation or astrocytes in a specific functional state. Received 6 June 2006; received after revision 25 July 2006; accepted 31 August 2006     

Opposite effects of beta-adrenoceptor stimulation and 8-bromo-cyclic AMP on potassium efflux in mammalian heart muscle

beta-adrenoceptor stimulation by isoprenaline increases the potassium efflux in beating guinea-pig atria. This effect is not mimicked by 8-bromo-cyclic AMP, a cyclic AMP analogue which exerts a positive inotropic effect in this preparation.     

Stimulation of hematopoietic stem cells by antilymphocyte serum]

The physiopathogeny of aplastic anemia is still unknown, it can be related to a stem cell defect or a microenvironment disease. An autoimmune origin is suspected but not as yet proved. To demonstrate the autoimmune origin of some cases of aplastic anemia, we have studied the effect of antilymphocyte globulin (ALG) on the hematopoiesis of aplastic patients by serial hematological and bone marrow investigation including blood counts, bone marrow cellularity, scanning with indium and technetium and granulocytic colonies in agar, 8 out of 17 patients had a response to ALG as shown by a rise of granulocytes and reticulocytes counts, increase of bone marrow cellularity and number of granulocytic colonies. This study tends to show that ALG has a stimulating effect on hematopoiesis in some cases of severe aplastic anemia.     

A paradoxical effect of 2,4-dinitrophenol in stimulating the rooting of hypocotyl cuttings ofPhaseolus mungo

Summary 2,4-dinitrophenol enhanced root formation on dark-grown hypocotyl cuttings ofPhaseolus mungo. This effect is probably related to uncoupling of oxidative phosphorylation and not through IAA-metabolism as is evident from studies with respiratory inhibitors (Cd²⁺) and non-phenolic uncouplers of oxidative phosphorylation (arsenate).The research has been financed by a grant from United States Department of Agriculture.     

Heterogeneous effects of sinusoidal muscular stretching on frequency grams of primary endings due to stimulation of static gamma axons]

The action of sinusoidal stretching at 1,5 Hz on primary ending frequencygrams due to repetitive stimulation of static gamma axons has been studied, in nembutalized cats, on flexor hallucis longus muscle spindles. Whenever, in static conditions, driving is elicited by the repetitive stimulation of gamma axons, the elementary components of the frequencygrams increase in amplitude during muscle stretch. This effect is not observed when the stimulation of the gamma axons gives a regular acceleration of the primary endings without "driving".     

Partial purification and characterization of acid phosphatase from sporulated oocysts of Eimeria tenella

Acid phosphatase of Eimeria tenella oocysts (Peak II) was purified 77-fold with a recovery of 26% using protamine sulfate precipitation, DEAE-cellulose chromatography and Sephadex G-200 gel filtration. This enzyme occurs in multiple forms as indicated by two peaks which can be separated by DEAE-cellulose chromatography and polyacrylamide gel electrophoresis. The partially purified enzyme has optimal activity at pH 4.5. With p-nitrophenyl phosphate the Km and Vmax values for (Peak II) were 25 mM and 1.57 mumol/min/mg protein, respectively. The enzyme (Peak II) is strongly inhibited by Hg++, Cu++, iodoacetamide, fluoride and molybdate. Tartrate and other divalent metal ions have no effect on enzyme activity. The partially purified Peak II phosphatase is not a glycoprotein as it is not absorbed on concanavalin-A Sepharose and its treatment with bacterial neuraminidase does not alter its elution profile through DEAE cellulose.     

Nouveau principe de stimulation électrique: L'excitation ambipolaire par courant alternatif,sinusoïdal pur,de fréquence moyenne

Summary Impulses of amplitude-modulated middle-frequency current (20 000 c.p.s.) stimulate nerve simultaneously at both poles. No polarity effect is observed, because no rectification occurs in the stimulation circuit if pure sine-wave middle-frequency current is employed. This principle is demonstrated by using bipolar longitudinal stimulation that, above threshold, elicits action currents, with latency difference corresponding to the distance between the stimulating electrodes. With supramaximum strength, maximum action currents are obtained at either pole, as is the case with ordinary cathodal stimuli of supramaximum strength applied to one pole or the other. Middle-frequency stimulation, therefore, has to be regarded asambipolar, i.e. does not depend on polarity. With second harmonic distortion, however, rectification occurs in the stimulation circuit and contamination by direct-current component ensues. Middle-frequency stimulation can be applied across nerve, since the excitatory effect does not apparently depend on longitudinal current flow. This method allows the action current to be recorded at the site of stimulation with minimum stimulus artefact.     

A phenomenological solution to the measurement problem? Husserl and the foundations of quantum mechanics

The London and Bauer monograph occupies a central place in the debate concerning the quantum measurement problem. Gavroglu has previously noted the influence of Husserlian phenomenology on London's scientific work. However, he has not explored the full extent of this influence in the monograph itself. I begin this paper by outlining the important role played by the monograph in the debate. In effect, it acted as a kind of ‘lens’ through which the standard, or Copenhagen, ‘solution’ to the measurement problem came to be perceived and, as such, it was robustly criticized, most notably by Putnam and Shimony. I then spell out the Husserlian understanding of consciousness in order to illuminate the traces of this understanding within the London and Bauer text. This, in turn, yields a new perspective on this ‘solution’ to the measurement problem, one that I believe has not been articulated before and, furthermore, which is immune to the criticisms of Putnam and Shimony.     

First identification of a trail pheromone of an army ant (Aenictus species)

Totally blind army ants carry out massive and highly organised foraging raids, apparently guided by chemical stimuli. Until now, this phenomenon has not been closely analysed. The existence of a trail pheromone in a postpygidial gland of anAenictus species has been demonstrated and the substances identified as methyl anthranilate and methyl nicotinate The pheromone consists of two parts: a primer effect, caused by methyl nicotinate, which prepares workers to follow trails, but is not itself followed, and a releaser effect, due to methyl anthranilate, which causes trail-following only in conjunction with the primer substance.     

Facilitation of avoidance conditioning by reticular stimulation in the cat]

Learning is facilitated in Cats by posttrial reticular stimulation. It has been pointed out that this stimulation has no immediate anterograde effect and does not evoke any change in the cortical, motor or autonomic functions during its delivery. Moreover this stimulation has no effect on the time course of cortical and autonomic responses to the conditioned stimulus. Therefore, these results suggest that reticular stimulation has a specific action on memory consolidation or information processing.