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Objects are reactive in the sense that they change state only when one of their methods is invoked by other objects. Reactive objects are sufficient in a client-server model of computation with a remote invocation mechanism "a la RPC". However active objects are much more powerful mainly because they are autonomous entities. Epidaure's objects are a particular type of active objects from which multi-agent systems can be built. In the context of mobility, migration becomes a necessity. For instance, a mobile client may disconnect from its server and reconnect to another server at a later time. In this paper we describe in a detailed manner the communication mechanism of a particular multi-agent system, Epidaure, and how the communication algorithm and mobility protocols that we developed can be applied to address problems related to mobile objects (e.g., registration, transport, tracking, ...).

1. We investigated the role of arachidonic acid metabolism and assessed the participation of mast cells and leukocytes in neurogenic inflammation in rat paw skin. We compared the effect of lipoxygenase (LOX) and cyclo-oxygenase (COX) inhibitors on oedema induced by saphenous nerve stimulation, substance P (SP), and compound 48/80. 2. Intravenous (i.v.) pre-treatment with a dual COX/LOX inhibitor (RWJ 63556), a dual LOX inhibitor/cysteinyl-leukotriene (CysLt) receptor antagonist (Rev 5901), a LOX inhibitor (AA 861), a five-lipoxygenase activating factor (FLAP) inhibitor (MK 886), or a glutathione S-transferase inhibitor (ethacrynic acid) significantly inhibited (40 to 60%) the development of neurogenic oedema, but did not affect cutaneous blood flow. Intradermal (i.d.) injection of LOX inhibitors reduced SP-induced oedema (up to 50% for RWJ 63556 and MK 886), whereas ethacrynic acid had a potentiating effect. 3. Indomethacin and rofecoxib, a highly selective COX-2 inhibitor, did not affect neurogenic and SP-induced oedema. Surprisingly, the structurally related COX-2 inhibitors, NS 398 and nimesulide, significantly reduced both neurogenic and SP-induced oedema (70% and 42% for neurogenic oedema, respectively; 49% and 46% for SP-induced oedema, respectively). 4. COX-2 mRNA was undetectable in saphenous nerves and paw skin biopsy samples, before and after saphenous nerve stimulation. 5. A mast cell stabilizer, cromolyn, and a H(1) receptor antagonist, mepyramine, significantly inhibited neurogenic (51% and 43%, respectively) and SP-induced oedema (67% and 63%, respectively). 6. The co-injection of LOX inhibitors and compound 48/80 did not alter the effects of compound 48/80. Conversely, ethacrynic acid had a significant potentiating effect. The pharmacological profile of the effect of COX inhibitors on compound 48/80-induced oedema was similar to that of neurogenic and SP-induced oedema. 7. The polysaccharide, fucoidan (an inhibitor of leukocyte rolling) did not affect neurogenic or SP-induced oedema. 8. Thus, (i) SP-induced leukotriene synthesis is involved in the development of neurogenic oedema in rat paw skin; (ii) this leukotriene-mediated plasma extravasation might be independent of mast cell activation and/or of the adhesion of leukocytes to the endothelium; (iii) COX did not appear to play a significant role in this process.

The genotypes of 50 isolates of Aspergillus fumigatus from 11 patients with invasive aspergillosis, obtained from three hospitals in different geographical areas, were determined by multilocus enzyme electrophoresis (MLEE). The study analysed the genetic polymorphism of multiple isolates from the first sample. Seven of the 14 enzymic loci studied were polymorphic, giving rise to eight different electrophoretic types. For nine of 11 patients studied, no polymorphism was observed in isolates within the first clinical sample. Analysis of genetic distance between electrophoretic types demonstrated a genetic heterogeneity within each geographical site. Moreover, some genotypes were preferentially found in a given area and this revealed a population structure within these geographical sites. Therefore, the epidemiology of A. fumigatus should be considered separately for each of these areas. The multiple discriminatory markers of MLEE seem to provide a powerful tool for increasing the understanding of the biology of this fungus.

Due to the important role that mating systems play in the evolution of species, we investigate the selfing rate and mate choice in the simultaneous hermaphroditic parasite Echinostoma caproni (Trematoda). The echinostomes were maintained in two situations in mice: (1) double infections where the two individuals do or do not belong to the same geographic area isolate, and (2) triple infections where two of the three individuals originate from the same isolate and the third one originates from a different isolate. This experimental design permits analysis of intra- and interisolate selfing rates and of mate preference. We predict, in the first experiment, no difference between intra- and interisolate selfing rates. In the second experiment we expect a preferential outcrossing between individuals originating from the same isolate in order to avoid hybrid breakdown. The results obtained corroborate our predictions and emphasize the important and synergistic roles of selfing, inbreeding depression, and hybrid breakdown in the evolution of echinostome reproductive strategies.

The vascular mechanism of action of cicletanine, an antihypertensive agent, was studied on isolated Wistar rat aorta in presence and in absence of endothelium both in normoxic and hypoxic conditions.Isolated aorta, from 24 month-old rats, were precontracted with noradrenaline (10(-7) M), in presence and in absence of endothelium and exposed to cumulative cicletanine concentrations in presence and absence of either L-NNA (10(-4) M) or indomethacin (Indo) (10(-7) M). Thereafter, aorta were precontracted by noradrenaline 10(-7) M, and hypoxia was induced by switching gas mixture from 95%O2/5%CO2 to 95%N2/5%CO2 during 10 minutes. Results are expressed as mean +/- sem and statistical analysis were done using one-way analysis of variance.When aorta were precontracted with noradrenaline (10(-7) M), in presence of endothelium, cicletanine (10(-9)-10(-4) M), induced a biphasic concentration-dependent relaxation (EC50 approximately 10(-7) M and 3 x 10(-5) M). In absence of endothelium, the effect of cicletanine was abolished (10(-9) and 10(-5) M). Whereas, at higher concentration (10(-4) M), the magnitude of the relaxation reached 94 +/- 2% and 67 +/- 5% of the initial developed tension in presence and in absence of endothelium respectively. The endothelium-dependent relaxation induced by cicletanine was significantly reduced by Indo (10(-7) M) (p0.05) and L-NNA (10(-4) M) (p0.005). Addition of 10 mM of BaCl2 significantly reversed the relaxation induced by the higher concentration of cicletanine used (p0.005). Under hypoxic conditions, the aorta, in presence of endothelium, displayed an increased developed tension which was significantly attenuated by cicletanine.These results indicated that cicletanine relaxes vascular smooth muscle through both, an endothelium-dependent action which was mediated by cyclooxygenase and NOsynthase pathways and an endothelium-independent action that was mediated through K+ channels opening. Under hypoxic conditions, our findings indicate that the effects of cicletanine, appear related to an endothelium protective action associated to NO release.

By using multilocus enzyme electrophoresis (MLEE) we have analyzed the genetic diversity encountered among chlamydospore-positive Candida albicans strains. While the type II strains of the former C. stellatoidea were genetically indistinguishable from those of C. albicans, type I strains constituted a distinct subgroup compared with C. albicans strains. Nevertheless, all these strains remained genetically very closely related compared with other species of Candida (e.g. C. tropicalis, C. krusei and C. glabrata). These results corroborate the synonymy between C. stellatoidea and C. albicans. Chlamydospore-positive C. albicans strains with atypical sugar assimilation patterns displayed a great genetic divergence from the cluster constituted by C. albicans and the strains of the former C. stellatoidea. However, these atypical strains were more closely related to C. albicans than they were to C. tropicalis, C. krusei or C. glabrata. These strains represent a genetically entity distinct from the typical C. albicans strains used in this study. The data also support the view that the atypical strains described here belong to the same genetic group as atypical C. albicans strains previously described by others.

One cause of aseptic loosening of total hip replacement (THR) results from the hard polymetylmethacrylate (PMMA) bone cement debris embedded within some of acetabular cups [1]. To prevent this failure, PMMA can be replaced by a titanium coating with a specific roughness to promote the bone bonding. In this work, inert and atmospheric plasma spraying was used to coat Ti.6A1.4V implants with titanium.] In order to evaluate the effect of the deposition process on the coating corrosion resistance, different electrochemical techniques were implemented in physiological (i. e., Ringer) and in acidic solutions. Results show that the spraying parameters and the coating morphology affect the corrosion behaviour. Thus, if the reactivity is not affected by the pH evolution, the pitting sensitivity depends on the process. It was found that coatings deposited under inert gas are free of oxides and dense, even when the atmosphere contains some hydrogen. In that case a significant improvement of the intrinsic localized corrosion resistance is observed versus deposits obtained using atmospheric plasma spraying.

To describe trends in the incidence of HIV infection diagnosis since 1985 in different at-risk groups in Aquitaine, south-west France.We analyzed the data from two regional surveillance systems on HIV infection: the hospital-based system of the Groupe d'Epidémiologie Clinique du SIDA en Aquitaine (GECSA) and the laboratory-based system of the Observatoire Régional de la Santé d'Aquitaine (ORSA). The number of intravenous drug users (IVDUs) in Aquitaine was estimated from two sources: a study performed by the GECSA in IVDUs treatment centers (1990-1991 data) and the annual surveys undertaken by the Ministry of Health (SESI) in all the health facilities and social services of the region from 1988 to 1993.As of December 31st, 1993, 3478 HIV-infected patients had been reported to the GECSA, including 3031 Aquitaine residents. Among those, 1096 were IVDUs without any other at-risk behavior (36.2%), the largest transmission category. The annual incidence of HIV diagnoses has steadily and considerably changed over time for IVDUs: 175 new cases diagnosed in 1985, 218 in 1987, then falling to 38 in 1993. During the same period, there was no marked decrease for homosexuals and the incidence of diagnoses of heterosexually-acquired HIV infections increased. Between 1989 and 1993, the number of HIV tests performed by the laboratories involved in the ORSA surveillance system increased steadily from 80,310 to 176,250 per year, when the number of first positive tests in Aquitaine residents decreased from 744 to 319 per year (-57%). This decrease was greater for IVDUs (-80%) than for the other groups. The survey performed by the GECSA estimated that 990 IVDUs were followed annually by treatment centres in Aquitaine in 1990-1991. This figure was stable and in agreement with the results of the SESI surveys performed throughout the period.The incidence of new diagnoses of HIV infection has been decreasing in Aquitaine since 1988, particularly among IVDUs, suggesting that the epidemic is slowing down. It is essential to maintain these systems of epidemiological surveillance as a component of the HIV prevention program.

In order to recognize particular characteristics of pathogenic strains, epidemiologic markers of 27 Staphylococcus epidermidis strains (9 pathological and 18 commensal) were studied. Nine strains were responsible of infective endocarditis (8 on native valves, and 1 on prosthetic valve). No case occurred after admission to hospital or surgery. Eighteen commensal strains were isolated from control subjects who had had no contact with the hospital environment and who had not received a recent antibiotic treatment. The microbiological characteristics were so diverse that no differentiation between the pathogenic strains and commensal strains could be done and no particular pathogenic clone was recognized.

Les progeniteurs cardiaques issus de cellules souches embryonnaires humaines apparaissent comme de bons candidates dans la prevention et le traitement de la dysfonction cardiaque par therapie cellulaire. Cependant, la greffe de cellules presentant des proprietes electriques indesirables pourrait predisposer les patients a des arythmies. Il est donc important de caracteriser les proprietes electrophysiologiques des progeniteurs cardiaques avant transplantation. Les cellules progenitrices cardiaques utilisees sont derivees de la lignee HUES-24 et selectionnees sur leur capacite a exprimer SSEA-1 apres une induction de 4 jours par le BMP2. A l’aide de la technique de patch-clamp en configuration cellule entiere, nous avons pu enregistrer des courants Ca2+ et K+, 24 a 48 H apres la selection. Les courants Ca2+ observes (2,22 ± 0.30 Pa/pF) sont de type L, aucun courant de type T n’ayant ete detecte dans ces conditions. Ces courants sont insensibles a l’isoproterenol (1μm) et a la forskoline (30μm) suggerant l’absence de regulation β-adrenergique. Des courants K+ actives par depolarization (6.79 ± 1.10 Pa/pF) sensibles au tetraethylammonium (10 mM) et a la 4-aminopyridine (5 mM) ont ete caracterises. Ces courants rectifiants sortants ressemblent aux courants rectifiants sortants retardes (IKDR) deja decrits sur des cellules souches embryonnaires murines. En revanche, aucun courant entrant active par hyperpolarisation n’a ete observe. Finalement, aucune conductance Na+ n’a pu etre mise en evidence. Sur les cellules n’exprimant pas SSEA-1, utilisees comme controles negatifs, aucun courant Ca2+, K+ ou Na+ n’a ete detecte. Le profil moleculaire des canaux ioniques exprimes par les cellules progenitrices est aborde parallelement par une approche genomique a l’aide de la RT-PCR haut debit. En conclusion, les cellules souches embryonnaires humaines presentent les courants majeurs impliques dans l’electrogenese cardiaque des 24 h apres leur orientation cardiaque. Neanmoins, l’absence de regulation β-adrenergique et de courants Na+ souligne l’immaturite de ces cellules comparees aux cardiomyocytes matures. Le suivi de la genese des proprietes electrophysiologiques de ces progeniteurs cardiaques, dans le contexte d’une therapie cellulaire cardiovasculaire, devrait nous permettre d’explorer la capacite de ces cellules a exprimer un phenotype electrophysiologique mature et a etablir des couplages excitation-contraction avec les cellules hotes

Several 1,2,3,4-tetrahydro-6-methyl-4-(substituted phenyl)-2-thioxo-5-pyrimidinecarboxylic acid methyl esters were synthesized by condensing thiourea with methyl acetoacetate and substituted benzaldehydes according to Biginelli reaction. The structures of the compounds were confirmed by spectral and elemental analysis and their calcium antagonistic activities were investigated. Furthermore, the compounds synthesized in previous and present studies were evaluated for their antiaggregating activities.

Biochemical and electrophysiological techniques were used to describe the Ca2+ channel blocking properties of a new dihydropyridine derivative, S11568 (+/-)- ([(amino-2-ethoxy)-2-ethoxy]methyl)-2-(dichloro-2',3'-phenyl)-4- ethoxy-carbonyl-3-methoxycarbonyl-5-methyl-6-dihydro-1,4-pyridine and its enantiomers S12967 ((+)-S11568) and S12968 ((-)-S11568). In binding studies, S11568 and S12968 displaced specifically bound [3H]PN 200-110 from cardiac and vascular smooth muscle preparations with potencies of 5.6-51 nM, respectively. S12967 was 6- to 18-fold less potent than S12968. A good correlation was found between the IC50 value for the inhibition of 45Ca2+ uptake by A7r5 aortic smooth muscle cells and binding data. Whole-cell patch clamp studies in both guinea-pig ventricular myocytes and A7r5 cells yielded similar results. At holding potential (VH) -50 mV, S12968 inhibited L-type Ca2+ current with an IC50 value near 70 nM, 2- to 3-fold more potently than S11568 and 30-fold more potently than S12967. With VH -100 mV, all three compounds were less potent, with IC50 values ranging from 500 nM to 3 microM. These results demonstrate conclusively that S12968 is the more active enantiomer. Furthermore, the pronounced voltage dependence of its actions in vitro suggests that in vivo it could exhibit good selectivity for vascular smooth muscle over cardiac muscle.

The API 20 EC and ATB 32 GN identification systems were compared for their ability to identify 231 coliform bacteria strains. Agreement with the identification given by conventional methods was achieved for 96.1 p. cent of strains by the API 20 EC gallery and for 95.9 p. cent by the ATB 32 GN system. Complementary tests were needed to identify 9.5 p. cent of strains using the API 20 EC system but 30.3 per cent using the ATB 32 GN system.

Residents are exposed to various situations contributing to the development of their CanMEDS roles. Exposure to different clinical scenarios and teaching situations contributing to the development of the CanMEDS roles could be identified, documented by residents and corroborated by staff supervisors retrospectively. A rapid and thorough method to assess this exposure is not available and could help to monitor a programs strengths and weaknesses. Daily activities developing specific CanMEDS roles where identified initially by the program director and residents. An internet based automatic survey generator (residentevaluation.com) was built to interrogate residents on a weekly basis on their exposure these clinical activities, linked to the seven CanMEDS roles. The surveys where automatically directed to supervisors for corroboration and comments. Periodic and annual reports where sent to the program director. The study group was composed of the Université de Montréal cardiac surgical trainees (n=6). Weekly surveys were sent from July 2006 to March 2007 (Ongoing). Participation rose from 42% to 79% in trainees and was 70% among supervisors. Time to fill the weekly survey was less than 1 minute for trainees and supervisors. The majority of residents documented development of all seven CanMEDS roles on a weekly basis. The trainees were exposed on a weekly basis to a reflection on the development of their CanMEDS competences. Cardiac surgical trainees at Université de Montréal are exposed and develop their CanMEDS roles over their regular training. The residentevaluation.com program allows a rapid weekly assessment and documentation of exposure to CanMEDS roles. The tool provides periodic and annual reports for program directors to quantify this exposure and adjust the program objectives. This software could be used in other programs to assess its efficiency in different cohorts. Frank, JR, ed. 2005. The CanMEDS 2005 physician competency framework. Better standards. Better physicians. Better care. Ottawa: The Royal College of Physicians and Surgeons of Canada Frank JR, Jabbour M, Fréchette D, Marks M, Valk N, Bourgeois G, eds. Report of the CanMEDS Phase IV Working Groups. Ottawa: The Royal College of Physicians and Surgeons of Canada. March, 2005.

Recent advances in ecology have suggested that parasites, through the spectrum of their effects, could act as key species in ecosystems. Wetlands are productive ecosystems within which parasitism is diversified. There already exists evidence for direct and indirect effects of parasites on their host species. The influence of parasites on the population ecology of hosts includes survival, castration, sexual selection, predation, and spatial distribution. Parasites can also affect the evolution of host biological diversity (i.e., genetic structure and interspecific competition) and trophic interactions between prey and predators. The key role parasites might play in the ecology of coastal waters and wetlands should be considered in conservation programs applied to such ecosystems.

We present a twenty-year-old patient's case. The initial report was: conversive hysteria. A cerebellous syndrom with myoclonias and psychiatric disorders without biologic or RMI abnormality leads to a Creutzfeld-Jakob diagnosis. This case is the nineteenth one published after human growth hormone use before 1988.

A simple rugged position‐sensitive detector for electronic readout of charged particles analyzer is described. It consists of a terminated electrical line with almost distributed RC constants. The prototype detector consists of 560 RC groups of total length 28 mm. Techniques pertinent to printed circuits have been used. A mathematical treatment of a realistic theoretical model is presented together with preliminary experimental results.

Apamin, a bee venom polypeptide, was recently reported to block specifically the Ca2+-dependent K+ channels that are not blocked by tetraethylammonium chloride in muscle cells. We report here that apamin blocked the naturally occurring slow action potentials (APs) in cultured cell reaggregates from chick hearts. The effects of apamin were not reversible on washout with Tyrode solution only (up to 24 h), but quinidine (10(-8) M) reversed the apamin blockade of the slow channels. Apamin also blocked the isoproterenol-induced slow APs in freshly isolated chick ventricular cells depolarized by 22 mM extracellular K+ concentration ([K+]o) in a dose-dependent fashion (10(-12) to 10(-10) M). Apamin at 5 X 10(-11) M blocked the isoproterenol-induced slow APs without affecting the membrane potential. Washout (with Tyrode solution containing 22 mM [K+]o and 10(-6) M isoproterenol) did not recover the slow APs. However, recovery of the slow APs was possible only when quinidine (10(-8) M) was added to the superfusion medium. The fast APs were rapidly restored by washout with Tyrode solution only. The present data show that apamin is a highly specific compound that tightly binds to the Ca2+ slow channels, thus blocking the slow APs in heart muscle. In addition, quinidine antagonizes the apamin binding on the slow APs.

Cyclic AMP levels were determined in young (day 4) and old (day 16) embryonic chick hearts, fresh and cultured. The 4-day hearts contained 33.6±2.2 pmol/mg protein, and isoproterenol (5 × 10−5 m ) elevated this to 118.9±1.5. When they were organ-cultured for 7 days, the cyclic AMP level decreased markedly to about 6.0 pmol/mg protein. Isoproterenol caused a large rise to 37.7±4.7. When cells were separated by trypsin and cultivated in vitro for days, their cyclic AMP levels were lowered to 5.6±1.4, and isoproterenol raised the level to 28.8±2.0 pmol/mg protein. The 16-day hearts contained 11.7±1.5 pmol/mg protein, and isoproterenol elevated this to 22.0±1.5. When old hearts were organ-cultured, their cyclic AMP level decreased somewhat to about 5.3 pmol/mg protein, and isoproterenol raised it to 17.9±2.0. When cells were separated by trypsin and placed into cell culture for 7 days, their cyclic AMP levels were low, about 4.4 pmol/mg protein, and isoproterenol raised the level to about 23.6. The results indicated that: (a) Young hearts in situ have a high cyclic AMP level. (b) Young and old hearts placed into organ and cell culture have low cyclic AMP levels, and isoproterenol is capable of producing very large increases. (c) Beta-adrenergic receptors are present in the young hearts. (d) Beta-adrenergic receptors of young and old hearts are retained in culture. (e) There seems to be no relationship between basal intracellular cyclic AMP levels and membrane electrical properties.

Une etude globale des Metazoaires parasites de Boops boops (L., 1758) a ete effectuee dans le golfe du Lion. Quatorze especes differentes (huit Plathelminthes, un Nematode et cinq Crustaces) ont ainsi ete inventoriees. Leurs localisations respectives sur l’hote, les prevalences globales et specifiques correspondantes ainsi que leurs variations en fonction de la taille des poissons, et leurs abondances ont ete precisees. Les associations parasitaires ont egalement ete determinees.

The present measurement techniques, adapted to the transient hot‐wire method for absolute thermal conductivity determination, allow the realization of a simple apparatus giving automatically precise digital data. It can be connected to a printer or, better, to a computer unit. This device has been tested with a liquid cell and satisfactory agreement with published values was obtained.

SUMMARYAcanthocephaloides geneticus sp.nov. is described from Arnoglossus laterna (Bothidae) from the Mediterranean littoral (Sète-France). The new species most closely resembles Acanthocephaloides propinquus (Dujardin, 1845) Meyer, 1932, whose type host is Gobius niger (Gobiidae). A genetic comparison of the parasites collected from these two Teleostean fishes has confirmed the value of morphological differences which seemed too slight to raise the populations to species status.

The use of microchannel electron multipliers in laboratory instrumentation as a detecting system coupled to an x‐uv monochromator or spectrograph, or to a low energy particle spectrometer, corresponds to a particular class of operation in which the detectors are exposed to a very low average input current and to stringent operational conditions, imposed by the instrument concept. It is shown in this paper that frequent vacuum breakings in the system containing the multiplier are not harmful to the stability of its performance. The monitoring of the strip current vs the applied potential is shown to be the simplest and most efficient way of assessing the state of the detector, as, in this particular regime of operation, it is necessary to follow a precise operating procedure to limit spurious secondary effects correlated to the water vapor contamination of its emissive surface.

Ce travail est realise a partir de deux populations de Cestodes appartenant a l’espece nominale Bothriocephalus scorpii (Mueller, 1776) (Cestoda, Pseudophyllidea), parasites du Turbot et de la Barbue sur le littoral mediterraneen et pour lesquelles, a partir de l’etude des isoenzymes (Renaud et al., 1983) nous avons attribue les denominations suivantes :—Bothriocephalus (supra sp. scorpii) gregarius, parasite du Turbot.—Bothriocephalus (supra sp. scorpii) barbatus, parasite de la Barbue.Nous recherchons a identifier ces deux populations a partir de criteres biochimiques.L’etude des fractions proteiques par electrophorese sur gel d’acrylamide montre l’existence dans les deux populations de 19 fractions proteiques distinctes. Deux d’entre elles (Rf 53 et Rf 87) sont presentes uniquement chez B. barbatus et une fraction de Rf 42, absente de ce dernier, se retrouve chez B. gregarius. Par contre, la fraction de Rf 27 n’est presente que chez B. barbatus. L’application de l’immunoelectrophorese met en evidence 7 ou 8 fractions antigeniques majeures selon la population etudiee ; cinq d’entre elles sont communes aux deux populations. Les reactions d’epuisement d’immunserum nous ont permis de caracteriser 3 arcs de precipitation propres aux Cestodes de la Barbue, correspondant aux fractions proteiques de Rf (27, 53, 87) et 3 arcs chez le Cestode du Turbot ; ceux-ci correspondent aux fractions proteiques de Rf (42, 21, 66).

Because young (2- to 3-days-old) embryonic chick hearts organ cultured in vitro for 1 to 2 weeks do not gain the fast Na + channels that they normally would during in situ development, instead retaining their high density of tetrodoxin (TTX)-insensitive slow Na + channels, we tested whether revascularization and blood perfusion allow membrane differentiation to proceed. Young hearts (3-day-old) (ventricular portion) and old hearts (16-day) (small pieces of about 1 mm 3 ) were grafted on to the chorioallantoic membrane of a host chick (6-day-old) where they were revascularized by the host circulation; for comparison, hearts were also placed into test-tube organ culture. After periods of 1 week (grafts) and 2 weeks (test-tube cultures), the tissues were removed for intracellular microelectrode recordings. The young hearts had electrical activity similar to fresh non-cultured 3-day-old hearts, i.e., the cells failed to further differentiate in culture. The cells had low resting potentials and slowly-rising (5–10 V/s) TTX-insensitive action potentials. There was no difference in results between the two culture methods. The old hearts cultured by either method had electrical activity similar to fresh non-cultured 16-day-old hearts, i.e., the cells retained their highly differentiated state. They had high resting potentials and fast-rising action potentials which were completely abolished by TTX. The action potential duration was longer in the grafted hearts (young and old) than in the test-tube hearts. Hence, young or old myocardial cells tend to retain the membrane cation channels that they originally possessed when placed into culture, and the young grafted hearts fail to gain TTX-sensitive fast Na + channels, even though blood perfused.

DNA could not be quickly extracted from members of the genus Actinomyces by the usual methods of lysis. Treatment of 7 different actinomyces cells with lysozyme and achromopeptidase, both 5 mg/g wet cells, for 2 h, followed by SDS (0.2%), proteinase K (5 mg/g wet cells) and EDTA (lmM) for 1 h, lysed the cells. The yield obtained in one day was 337 micrograms per 200 mg of bacterial cells. The treatment was also found to work effectively on strains belonging to Veillonella, Staphylococcus, Fusobacterium and Bifidobacterium genera.

Let G be a locally compact group with Fourier algebra A ( G ) A(G) . We prove that if G is amenable then every centralizer of A ( G ) A(G) is determined by multiplication with an element of the Fourier-Stieltjes algebra of G. This result is then used to show that isometric centralizers correspond to characters of G.

Details are presented of an image intensifier for electrons using a channel plate, scintillator, and fiber optics combination, which gives a reduction in exposure time of several thousand compared to a photographic plate. During the course of the investigation, measurements were made on the characteristics of the channel plate for various electron energies and angles of incidence.

A rapid and simple method for lysing anerobic Gram-positive rods is described. It is based on the simultaneous action of lysozyme and achromopeptidase (each at 5 mg/g wet weight of cells), followed by the action of SDS (0.2%). The efficiency of the bacterial lysis is measured by the yield of DNA obtained with Marmur's modified procedure. This method permits effective lysis of small amounts of anaerobic rods (200 mg wet weight) independent of their growth phase, and extraction of DNA for further analysis. It is particularly useful for strains with low growth such as certain species of Actinomyces and Bifidobacterium and it saves considerable time.

Clinical and biological criteria of myopathies associated with carnitine deficiency allow to distinguish a muscular and a systemic form of the condition. In this report, the results of clinical, pathological and electrophysiological data obtained from a patient with carnitine deficiency-linked myopathy are described. The patient was a 23-year-old girl who was previously known to suffer from muscle weakness when suddenly acidosis associated with a severe drop in plasma carnitine appeared. In addition there were hypermetabolic symptoms similar to those described in Luft's syndrome. Biopsy from the quadriceps femoris muscle before treatment revealed that all type I fibers were either hypotrophic or atrophic. They showed lipid overloading manifested by triglyceride droplets adjacent to the mitochondrial membrane. Furthermore, the level of soluble muscle carnitine was 83 p. 100 less than in controls and membrane linked muscle carnitine was also 73.5 p. 100 less than in controls. The patient rapidly recovered after the initiation of daily treatment with 4.40 g carnitine chlorhydrate associated with 50 g Lipogram 20. Nine months later, lipid overloading completely disappeared and the level of plasma carnitine returned to near normal whereas the level of both soluble and linked carnitine remained very low. To provide more information on the origin of the myopathy (myogenic, neurogenic or humoral) we carried out an electrophysiological investigation of cultured skeletal muscle cells from the patient and from biopsies of patients not known to be suffering from myopathy. The electrophysiological data showed that the patient myotubes were less polarized than myotubes from control patients. Furthermore, the amplitude of the action potential was smaller than the amplitude of the action potential measured in control cells. Daily addition of 50 microM carnitine chlorhydrate to the cultured myotubes induced a recovery of the action potential amplitude. Taken together these results indicate that the carnitine deficiency reported here was probably of systemic origin in addition to a myogenic component. Muscle deficiency could be either linked to an alteration in the carnitine pathway or to overconsumption of carnitine by muscle. This latter point is discussed.

[3H]Desmethoxyverapamil, (S/-)[3H]bepridil, and d-cis-[3H]diltiazem bind to skeletal muscle transverse-tubule (T-tubule) membranes with affinity constants in the range of 2-50 nM and with Bmax values of the order of 50-80 pmol/mg of protein. These drugs are mutually competitive and modulate allosterically the 1,4-dihydropyridine binding. The molecular size of the native [3H]nitrendipine receptor of T-tubule membranes has been determined using the radiation inactivation technique. The [3H]nitrendipine receptor was found to have a Mr of 210,000 +/- 20,000. Photoaffinity labelling using (+)[3H]PN 200-110 indicates the presence in the dihydropyridine receptor of a polypeptide (or polypeptides) of Mr 170,000 +/- 5,000. The 3-[(3-cholamidopropyl)-dimethylammonio]-1 propane sulfonate (CHAPS) solubilization of the T-tubule membranes preserved the binding properties of the different drugs to the calcium channel. The dihydropyridine-sensitive calcium channel has been substantially purified by a combination of ion exchange chromatography, lectin affinity chromatography, and gel filtration. The purified material contained polypeptides of apparent molecular weights of 142,000, 32,000, and 33,000, which copurified with (+)[3H]PN 200-110 binding activity. Two stages in which there is an increased binding of [3H]nitrendipine have been observed during chick myogenesis in ovo. The first one occurs during embryonic life and has the same properties as in the in vitro development. The second stage occurs near hatching and corresponds to a large increase in the number of nitrendipine receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of short term stimulation of beta-adrenergic receptors and elevations in intracellular cyclic AMP on nitrendipine-sensitive voltage-dependent Ca2+ channels of skeletal muscle cells in vitro has been studied using both the 45Ca2+ flux technique and [3H] nitrendipine-binding experiments. Isoproterenol increased the nitrendipine-sensitive 45Ca2+ influx under depolarizing conditions. The effects of isoproterenol were additive to those of depolarization and were antagonized by alprenolol. Half-maximal inhibition of 45Ca2+ influx induced both by depolarization and by isoproterenol occurred at a nitrendipine concentration of 1 nM. Treatments that resulted in an increased level of intracellular cyclic AMP, such as treatment with 1-methyl-3-isobutylxanthine, theophylline, dibutyryl cyclic AMP, or 8-bromocyclic AMP also resulted in an increased rate of 45Ca2+ entry via nitrendipine-sensitive Ca2+ channel. In contrast, long term treatment of myotubes in culture with isoproterenol and other compounds that increased intracellular cyclic AMP led to a large increase in the number of nitrendipine receptors. This increase was accompanied by a 4-10-fold decrease in the affinity of the receptors for nitrendipine. Alprenolol inhibited the long term effects of isoproterenol. In vivo treatment of 7-day-old chicks with reserpine and alprenolol produced a decrease in the number of skeletal muscle nitrendipine receptors. This decrease in receptor number was accompanied by an increase in the affinity of nitrendipine for its receptor by a factor of 4 to 5. These effects on the nitrendipine receptor were prevented by simultaneous injection of isoproterenol. The results are discussed in relation to the role of beta-adrenergic receptors and intracellular cyclic AMP in the regulation of skeletal muscle Ca2+ channels.

A global study of the Metazoan parasites of Boops boops (L., 1758) have been made in the "golfe du Lion". Fourteen different species (eight Platyhelmintha, one Nematoda and five Crustacea) have been inventorized. Their respective localisation on the hosts, globals and specifics corresponding prevalences as well as their variations according to the size of the fish, and their abundance have been precised. Parasitics associations have also been examined.

Apamin is a neurotoxin extracted from bee venom (Habermann 1972). It is a polypeptide of 18 amino acids with two disulfide bridges (Fig. 1). It is the only polypeptide neurotoxin, as far as we know, that crosses the blood-brain barrier. Analysis of the structure-function relationships of this toxin has shown that two of the 18 amino acids in the sequence have particular importance for the action of the toxin; they are Arg-13 and Arg-14 (Vincent et al. 1975). These two residues seem to be essential elements of the active site of the toxin. Chemical modifications elsewhere in the sequence may decrease the toxicity of the polypeptide, but do not suppress its biologic activity. Cumulative chemical modifications — of the amino group and of the imidazole of His-18 for example — may, however, abolish the activity of the toxin (Vincent et al. 1975). Solid phase synthesis of apamin and analogs has been carried out (Cosand and Merrifield 1977; Granier et al. 1978). This approach has confirmed that the active site of apamin comprises the two residues Arg-13 and Arg-14. The exact three-dimensional structure of the toxin remains unknown. However, recent solution analysis of apamin by NMR techniques has suggested that the toxin is highly ordered with an α-helical core and regions of β-type turns (Bystrov et al. 1980; Wemmer and Kallenbach 1983).

Two distinct and interdependent binding sites for inhibitors of voltage-dependent Ca2+ channels have been identified. They include one site for molecules of the 1,4-dihydropyridine serie such as nitrendipine, nifedipine or PN200-110 and one site for a chemically heterogenous group of compounds comprising verapamil, D600 and desmethoxyverapamil, bepridil and diltiazem. Ca2+ binds to its own coordination site which is distinct from the receptor site for organic Ca2+ channel inhibitors. The molecular size of the native [3H] nitrendipine receptor of transverse tubule membrane, brain and heart, have been determined using the radiation inactivation technique. The [3H] nitrendipine receptor is found to have a Mr of 210,000 +/- 20,000. CHAPS solubilization and purification indicate that the dihydropyridine receptor contains polypeptides of apparent molecular weights of 142,000, 32,000 and 33,000 which copurifie with (+) [3H] PN200-110 binding activity. Two stages in which there is an increased binding of [3H]nitrendipine have been observed during chick myogenesis. The first one occurs during embryonic life and has the same properties as in the in vitro development. The second stage occurs near hatching and corresponds to a large increase in the number of nitrendipine receptors. This increase is accompanied by a decrease in the affinity of nitrendipine for its receptor by a factor of 4 to 10. The second stage of development is partly under innervation control and its expression is modulated by the intracellular cyclic AMP content. The two dihydropyridines Bay K8644 and CGP 28932 work preferentially on polarized membranes. 45Ca2+ flux experiments yielded results which are in good agreement with electrophysiological, contraction and binding data obtained with rat cardiac cells and skeletal muscle cells.

The general security analysis calculation problem is considered. In on-line applications, the accuracy of the results obtained from such calculations depend on accuracy of the network model used in the calculations, and inaccuracies of the input data. The problem investigated exists whenever such security analysis calculation programs are planned to be installed. Six modelling problems are presented.