Showing papers by "University of Luxembourg published in 1993"

Benefits of Psychological Preparation for Surgery: a Meta-Analysis

Abstract: T hcre is now substuntial agreement that psychological prepLtruti(tn.for surger)' is henefcial to patients. It is irnportant, hov,(t(r, to establish which beneJtts can be achieved by psychological prepdratton artd rf all .forrns qf preparation are equally elJbctive. T'lre results o.f randomized c:ontrolled trials o,/'psvchological methods o.f preparing, adult patients.for surger), vyere anal,yzed in terms e.l etght outptit.t (negati\\'{'a./fect, pain, pain medit:ation, length of .\\ta). l)ehdvroral and clinical indit'es of recoverv, ph.vsiological indices, and satrs.fattion). Irt order to reduce publication bias, publishcd as vell as unpuhlished stttdies w'ere included in the ttreta-anal.r.sis. /1 nas conc'luded that signilicant benefts can be obtained on all o.f the nu.jor outt'orne v'ariahles that have been e.xplorecl. Procedural inlormation and behavioral insftuctions .sltov' the rnost ubiquitttu.s eflec:ts in irnproving nleasLtres of postoperalire re(o|err. 'fhe re.sults have implications for the improremeil o.{ patient care in surgical units. (Ann Behav Med 1993. I5(4):245-256)

Induction of immediate-early genes by angiotensin II and endothelin-1 in adult rat cardiomyocytes.

Abstract: Objective Few molecular signals for induction of myocardial hypertrophy have been identified. This study was carried out to investigate the action of angiotensin II and endothelin on the growth- and differentiation-related genes Egr-1 (early growth response gene 1) and c-fos in isolated adult rat cardiomyocytes. Methods Cardiac myocytes from male Wistar-Kyoto rats were isolated and incubated with angiotensin II and endothelin-1 in Dulbecco's modified Eagle's medium. RNA was isolated and blotted, and densitometric analysis was performed. All experiments were repeated at least three times. Results Endothelin-1 (10(-7) mmol/l) induced a 20-25-fold rise in Egr-1 messenger RNA within 15 min. This effect was dose-dependent. c-fos was induced 10-20-fold within 15 min with similar dose-response characteristics. Angiotensin II also induced Egr-1 and c-fos with kinetics similar to endothelin but a cofactor from fetal calf serum was needed for full c-fos expression. The protein kinase C activator phorbol 12-myristate 13-acetate also induced Egr-1. Conclusions The results identify Egr-1 and c-fos as target genes for the action of endothelin and angiotensin II in the adult myocardium suggesting that induction of the genes may be part of the signal transduction pathway for angiotensin II and endothelin in the myocardium.

Acute and Chronic Phases of Unilateral Inflammation in Rat's Ankle are Associated with an Increase in the Proportion of Calcitonin Gene‐related Peptide‐immunoreactive Dorsal Root Ganglion Cells

Abstract: Using immunocytochemical methods, the proportion of calcitonin gene-related peptide immunoreactive perikarya was determined in dorsal root ganglia L4-L6 in four control rats and in ten rats with a unilateral inflammation in the ankle region of the left hindlimb. The inflammation was induced by subdermal injection of Freund's complete adjuvant at the ankle. Swelling and cellular infiltration of the ankle region developed within 2 days, and were stable and restricted to the injected ankle for the duration of the 3-week study. In control rats approximately 24% of 20,419 perikarya showed calcitonin gene-related peptide (CGRP)-like immunoreactivity. In rats with unilateral inflammation the proportion of CGRP-positive neurons was increased on the inflamed side to approximately 32% of 11,454 cells at day 2 (P < 0.001 with respect to ganglia in normal rats) and approximately 29% of 10,739 perikarya at day 20 post inoculation (P < 0.01). By contrast, no significant changes were found between ganglia in the non-injected side (approximately 25% at day 2 and approximately 24% at day 20). These results demonstrate that peripheral inflammation is associated with an increase in the proportion of neurons in the dorsal root ganglia that synthetize CGRP. This up-regulation is already present at an early stage of inflammation but also at later stages, suggesting that the increased synthesis of CGRP is an important neurobiological reaction associated with the acute and chronic phases of inflammation.

Responses of rat medullary dorsal horn neurons following intranasal noxious chemical stimulation: effects of stimulus intensity, duration, and interstimulus interval.

Abstract: 1. Most quantitative examinations of nociception are performed with thermal or mechanical stimuli. Because nociceptive processing mechanisms may depend on the modality of the stimuli, comparable studies on chemonociception are necessary. 2. We examined the activity of chemonociceptive medullary dorsal horn neurons in halothane-anesthetized rats. For controlled noxious chemical stimulation, defined CO2 pulses were applied to the nasal mucosa. The effects of stimulus intensity, duration, and interstimulus interval (ISI) were tested by performing three different CO2 stimulation protocols (see below). 3. The recorded neurons were characterized by intranasal and facial stimuli of different modalities. The cells received input from intranasal A delta- and/or C-fibers. All tested neurons also responded to other intranasally applied irritants, e.g., mustard oil. Furthermore, the units were sensitive to intranasal high-threshold mechanical stimulation and to facial mechanical stimulation. According to the properties of their facial mechanoreceptive fields, the units were classified as wide dynamic range (WDR) or nociceptive specific (NS) neurons. The majority of the cells also responded to facially applied noxious heat stimuli, so that most of the recorded neurons were found to be multimodal. Some of the neurons, in addition, had convergent input from primary afferents innervating the maxillary tooth pulps or the cornea and periorbital structures. 4. In the first stimulation protocol we presented four different CO2 concentrations (25, 50, 75, and 100%; stimulus duration 2 s). In total, each concentration was applied 10 times (2 trains of 5 stimuli). Stimulus response functions (SRFs) were computed with average responses to identical stimuli. All but 2 of the 23 tested neurons displayed enhanced responses after stimulation with increasing intensities. In general, WDR cells (n = 15) discharged more vigorously to the same CO2 concentration than NS cells (n = 8). WDR neurons discriminated more reliably between stimulus intensities in the low to moderate range (25–50% CO2) than NS cells. Both categories of neurons, however, discriminated equally well in the moderate- to high-intensity range (50–75% CO2). The discriminatory capacity of WDR and NS neurons was reduced in the highest concentration range (75–100% CO2). The proportion of NS neurons significantly discriminating between these intensities tended to be higher compared with WDR neurons when stimuli were applied with long ISIs (120 s). 5. To examine the effects of the duration of the ISI, identical test sequences were performed with ISIs of 30 and 120 s. (ABSTRACT TRUNCATED AT 400 WORDS)

Degenerations of generalized Krichever–Novikov algebras on tori

Abstract: Degenerations of Lie algebras of meromorphic vector fields on elliptic curves (i.e., complex tori) which are holomorphic outside a certain set of points (markings) are studied. By an algebraic geometric degeneration process certain subalgebras of Lie algebras of meromorphic vector fields on P1, the Riemann sphere, are obtained. In case of some natural choices of the markings these subalgebras are explicitly determined. It is shown that the number of markings can change.

Differential Operator Algebras on compact Riemann Surfaces

Abstract: This talk reviews results on the structure of algebras consisting of meromorphic differential operators which are holomorphic outside a finite set of points on compact Riemann surfaces. For each partition into two disjoint subsets of the set of points where poles are allowed, a grading of the algebra and of the modules of lambda - forms is introduced. With respect to this grading the Lie structure of the algebra and of the modules are almost graded ones. Central extensions and semi-infinite wedge representations are studied. If one considers only differential operators of degree 1 then these algebras are generalizations of the Virasoro algebra in genus zero, resp. of Krichever Novikov algebras in higher genus.

Differential Operator Algebras on compact Riemann Surfaces

Abstract: Invited talk at the International Symposium on Generalized Symmetries in Physics at the Arnold-Sommerfeld-Institute, Clausthal, Germany, July 26 -- July 29, 1993. This talk reviews results on the structure of algebras consisting of meromorphic differential operators which are holomorphic outside a finite set of points on compact Riemann surfaces. For each partition into two disjoint subsets of the set of points where poles are allowed, a grading of the algebra and of the modules of lambda - forms is introduced. With respect to this grading the Lie structure of the algebra and of the modules are almost graded ones. Central extensions and semi-infinite wedge representations are studied. If one considers only differential operators of degree 1 then these algebras are generalizations of the Virasoro algebra in genus zero, resp. of Krichever Novikov algebras in higher genus.

Quantum groups and the recovery of U(3) symmetry in the Hamiltonian of the nuclear shell model

Abstract: Quantum groups are of current interest because of their applications in many fields of physics. In the present paper the authors discuss a q-analogue to the Hamiltonian of the nuclear shell model. If q is written as q=exp(i tau ) where tau is a real number in the interval 0

Le phénomène urbain : genèse et évolution

Abstract: L'histoire du phénomène urbain connaît un regain considérable d'intérêt depuis la parution en 1968 du recueil d'études édité par H.J. Dyos (1) : livres, articles, revues, collections, actes de colloques ont foisonné' '. Désormais, l'évolution de l'urbanisation européenne est connue dans ses grands traits grâce aux ouvrages de Jan de Vries, de Paul Hohenberg et Lynn Lees, de Bernard Lepetit et de Richard Lawton et Robert Lee pour ne citer que les plus récents. Grâce à son ouvrage de synthèse De Jéricho à Mexico Paul Bairoch nous pousse à dépasser le cadre européen et à envisager le phénomène urbain à l'échelon mondial. De plus, en 1988, Paul Bairoch et son équipe fournissaient une banque de données considérable sur les villes européennes qui renouvelle notre matériel documentaire et qui ouvre les portes à de fécondes analyses.