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Y Roche

Publications and source records attributed to Y Roche.

32 records · Page 2Linked to original sources
PubMed1987

Effects of quinolones on interleukin 1 production in vitro by human monocytes.

The new quinoline derivative antibiotics (quinolones), pefloxacin and ciprofloxacin at concentrations higher than 50 micrograms/ml inhibit the PHA response of the human mononuclear leukocytes in vitro. Since monocytes have been shown to be accessory cells for the activation of lymphocytes by mitogens, we investigated the effects of pefloxacin and ciprofloxacin on extracellular interleukin 1 (IL-1) and cell-associated IL-1 from lipopolysaccharide-stimulated human monocytes. Pefloxacin and ciprofloxacin decreased the extracellular IL-1 in a dose-dependent manner, while cell-associated IL-1 was not altered. These effects were observed even after a short period of incubation (1 or 2 h). No inhibitory activity against purified IL-1 or IL-2 could be demonstrated in the dialyzed supernatants from pefloxacin- or ciprofloxacin-treated monocytes. Neither pefloxacin nor ciprofloxacin modified the biological activity of preformed IL-1. The decrease of extracellular IL-1 induced by pefloxacin and ciprofloxacin could, in part, account for the observed decrease in the proliferative response of human mononuclear leukocytes to phytohemagglutinin, as extracellular IL-1 and proliferative response were positively correlated (at various concentrations of pefloxacin and ciprofloxacin). The decrease in extracellular IL-1 was not associated with any alteration in the expression of the HLA-DR antigen on the monocytes membrane. These data suggested that pefloxacin and ciprofloxacin could antagonize IL-1 production and release by lipopolysaccharide-stimulated monocytes. These quinolones could be interesting tools to study the production, processing, transport and release from the monocytes of IL-1.

Adult↗
PubMed1987

Comparative effects of quinolones on human mononuclear leucocyte functions.

The effects of three quinoline derivatives--pefloxacin, ciprofloxacin and ofloxacin--were investigated in mitogen-stimulated human peripheral blood mononuclear leucocytes (MNL). At concentrations of 50 mg/l or more, pefloxacin, ciprofloxacin or ofloxacin significantly inhibited MNL proliferation in response to phytohaemagglutinin. This inhibition was more marked with ciprofloxacin than pefloxacin or ofloxacin. To determine the possible mechanism(s) involved in the inhibition of MNL proliferation following exposure to pefloxacin, ciprofloxacin or ofloxacin, we assessed (1) interleukin-1 (IL-1) activity in supernatants from monocytes treated with the quinolones and (2) the effects of 2-mercaptoethanol (2-ME) a thiol compound which acts as an antioxidant agent and the effect of indomethacin (INDO) an inhibitor of prostaglandin E2 synthesis. 2-ME and INDO did not prevent the decrease in the proliferation. IL-1 activity was shown to be decreased for the same range of antibiotic concentrations as observed for the inhibition of MNL proliferation. Cellular viability of the MNL or monocytes was not modified by any of the quinolones at the concentrations tested. Taken together, these results suggest that pefloxacin, ciprofloxacin and ofloxacin act as immunomodulators. The mechanism involved with the cascade of events that leads to the lymphocyte proliferation and the clinical relevance need further investigation.

Cell Survival↗
PubMed1987

[Effect of antibiotics on IL-1 in vitro production by human monocytes].

The effects of penicillin, macrolides (spiramycin and erythromycin), cephalosporins (cefaclor and cefadroxil), cycline (doxycycline) and quinolones (pefloxacin, ciprofloxacin and ofloxacin) on extracellular and cell-associated interleukin-1 activity from human monocytes were investigated in vitro. When cells were treated with 10 micrograms/ml of quinolones, cephalosporins or penicillin, no effect on IL-1 production could be detected. Using 100 micrograms/ml, extracellular IL-1 activity was found to be decreased by quinolones (about 35% of the control without antibiotic) without modification of the cell-associated IL-1 activity. Extra and intracellular IL-1 was only slightly decreased by cephalosporins, while penicillin did not alter the IL-1 activities. Spiramycin and doxycycline using 100 micrograms/ml increased extracellular IL-1 while cell-associated was decreased. A toxic effect may have been exerted by these antimicrobial agents.

Anti-Bacterial Agents↗
PubMed1986

Macrolides and immunity: effects of erythromycin and spiramycin on human mononuclear cell proliferation.

Macrolides are actively concentrated by leucocytes. The dose-effect responses of spiramycin (Sp) and erythromycin (Er) on phytohaemagglutinin (PHA) and pokeweed mitogen (PWM) stimulated human mononuclear leucocytes (MNL) were studied. Cell viability was not altered at any antibiotic concentration (1-100 mg/l). Both Sp and Er showed dose-related inhibition of the proliferative response of PHA and PWM stimulated MNL. Very marked effects were observed at high antibiotic concentrations and the effects observed at low concentrations (1-10), although small, were also significant. Similar results were observed for the mitogen PWM. A decrease in tritiated thymidine (3H-TdR) incorporation occurred only if Sp and Er were added during the first 8 h of culture. Sp and Er also induced a decrease in tritiated uridine (3H-UdR) uptake. These data suggest that Sp and Er interfered with an early event in the cell cycle. However Sp did not affect PHA binding to MNL. The clinical significance of these findings is discussed.

Cell Division↗
PubMed1985

Immune oxidative injury induced in mice exposed to normobaric O2: effects of thiol compounds on the splenic cell sulfhydryl content and Con A proliferative response.

In vivo exposure of mice to normobaric O2 depresses the cellular immune response by a mechanism that remains unknown. In vitro oxidative injury leads to decreased sulfhydryl groups (SH) in lymphocytes. To determine whether in vivo exposure to O2 would have similar effects, we measured the SH content in spleen cells both from mice that had been exposed to normobaric O2 (O2 SC) and from controls exposed to ambient air (Air SC). The SH content of the fresh O2 SC was slightly decreased, whereas after 48 hr of culture, the SH content and the proliferative response of these cells were found to vary with the type and concentration of thiol or disulfide compounds added to the culture medium. Under standard culture conditions, i.e., RPMI 1640 medium containing 0.41 mM half-cystine, the SH content in O2 SC decreased sharply to about 10 and 20% that of Air SC in the absence or presence of Con A (2 micrograms/ml), respectively. Under these culture conditions, the proliferative response of O2 SC was 20.5% +/- 3.2 of Air SC. In cystine-free RPMI 1640 medium supplemented with various concentrations of L-cystine, L-cystine and 2-mercaptoethanol (2-ME), L-cysteine, or reduced glutathione (GSH), the proliferative response to Con A and the SH content of the O2 SC varied in parallel and were correlated (p less than 0.01). Half-cystine (0.41 mM) plus 2-ME (5 X 10(-5) M) or L-cysteine alone (4 mM) completely protected the SH content of O2 SC and induced a proliferative response 82% +/- 6 that of the controls. In cystine-free RPMI 1640 medium supplemented with GSH (4 mM), the SH content and proliferative response of O2 SC were 79 and 67.5% of Air SC, respectively. Other concentrations of these compounds were less effective. Oxygen scavengers such as SOD, catalase, mannitol, and vitamin E did not protect against the decrease of the O2 SC. The induced oxidative cellular damage might be related in part to a membrane lipid peroxidative process. These data show that in vivo exposure of mice to normobaric O2 induced lesions in splenic cells manifested under standard culture conditions by a decrease in both SH content and Con A proliferative response. The extent of these alterations could be modulated by variations of the thiol environment. Protection of the SH content correlated with protection of the proliferative response of the O2 SC.

Animals↗
PubMed1978

[Qualitative and quantitative determination of amino-2 benzimidazole in aqueous medium by polarography (author's transl)].

Amino-2 Benzimidazole, a residue of the decomposition of some fungicides (Benomyl, Carbendazine, Thiophanate, Methylthiophanate), is measured by polarography in aqueous medium, with a platinium rotating electrode, for the exploration in potentials from +0.5 v to 1.4 v. The best conditions for the quantitative determination are investigated, the study according to pH is performed and the standard curve is given for concentrations from 10(-5) to 10(-3) M/l. The interaction of elementts found in tap water and in aquarium water is also investigated.

Benzimidazoles↗
PubMedDate not supplied

Surface enhanced Raman scattering of a lipid Langmuir monolayer at the air-water interface.

Surface enhanced Raman spectra were recorded from a phospholipid monolayer directly at the air-water interface. We used an organized monolayer of negatively charged tetramyristoyl cardiolipins as a template for the electrochemical generation of silver deposits. This two-dimensional electrodeposition of silver under potentiostatic control was the substrate for enhancement of Raman spectra. We report the optimized conditions for the Raman enhancement, the microscopic observations of the deposits, and their characterization by atomic force microscopy. Laser excitation at 514.5 nm leads to intense and reproducible surface enhanced Raman scattering spectra recorded in situ from one monolayer of cardiolipin, using 0.5 mol % of 10N nonyl acridine orange or 5 mol % of acridine in the film, and demonstrates the possibility of estimating the pH at the metal/phospholipidic film interface.

Acridine Orange↗
PubMedDate not supplied

[Vasovagal syndrome].

The vaso-vagal syndrome, the most frequent accident may appear during dental treatments, can involve breve conscience loss. In case of important bradycardia, the medical treatment consists in an intravenous injection of atropine sulfate. Prevention of this syndrome consists in an anxiolytic and/or vagolytic premedication.

Anti-Anxiety Agents↗
PubMedDate not supplied

[Emergency drugs].

After setting the essential rules of the emergency prescription in the dental office, the authors consider successively from a standpoint of properties, indications, contra-indications, danger of associating medications, presentation, use and posology. The medicines used in order to treat the different emergency situations that can arise in a dental practice.

Adrenal Cortex Hormones↗
PubMedDate not supplied

[Allergic manifestations].

Physiologic principles, mediators, drugs and biologic agents involved in allergic reactions such as skin eruptions, local swelling and anaphylaxis are exposed. Then, clinical manifestations, diagnosis, treatment and preventive modalities are described.

Anaphylaxis↗
PubMedDate not supplied

[Behavioral disturbances and psychosomatic manifestations].

The psychological and psychiatrical behaviour troubles and the psychosomatical manifestations are very frequent in dental and oral surgery practice. Their variable expression is sometimes confuse for the practitioner who should quickly find the differential diagnosis with the imperative medical emergency. His attitude must be quiet and kind, still watching over the vital functions and waiting for the more frequent spontaneous favourable evolution.

Aggression↗