Effect of an auditory stress on peritoneal and alveolar cells in C57 BL/6J mice of advanced age.

The aim of this study was to analyse the effects of auditory stress on peritoneal and alveolar macrophages in C57 BL/6J mice of advanced age, and to compare the results to those obtained in old mice submitted to a sham stress, and to those observed in young mice submitted to the same auditory stress. We used a chemiluminescence assay to measure the production of free oxygen radicals (FOR) by macrophages. Eight 22 month-old mice were exposed to a sound stress of 110 dB for three consecutive nights; nine were submitted to a sham stress. The results were compared to those obtained in young (8 week-old) mice, 21 submitted to noise stress, and 17 controls. The corticosterone level was not increased after stress in any group. FOR production in old mice was significantly higher than that in young mice. Stress did not induce significant changes in FOR production by alveolar cells in young mice; however, the FOR production by alveolar cells was significantly higher in the stressed group than in the control group of old mice. These results show that noise stress is associated with modifications of macrophage functions that are influenced by cell localization, the behaviour of alveolar and peritoneal macrophages of old mice being clearly different in our experimental model.

Alteration in the production of free oxygen radicals and proinflammatory cytokines by peritoneal and alveolar macrophages in old mice and immunomodulatory effect of RU 41740 administration. Part I: Effect of short and repetitive noise stress.

The aim of this study was to analyze the effects of stress on natural immunity in old mice, and the potential of an immunomodulating drug to correct stress-induced immune abnormalities. We analyzed both the alveolar (ALM) and peritoneal macrophage (PerM) oxidative responses and cytokine productions of TNF-alpha and IL-1alpha, in old mice after exposure to 3 days of noise stress, with and without treatment with RU 41740, an immunomodulating compound. Production of Free Oxygen Radicals (FOR) by ALM and PerM macrophages was evaluated using a luminol-dependent chemiluminescence method at the basal state and after stimulation. Serum corticosterone was also measured. Three groups of 22-24 month-old C57BL/6 mice were studied. Seven mice were treated with RU 41740 (10 mg kg(-1)) every day for 5 days and then exposed to sound stress (110 dB, 1000 Hz, for 3 nights). Ten mice were treated with saline, then submitted to a sham stress. Eight animals received neither treatment nor stress. There was no difference in corticosterone level between the three groups and between these groups and a control group nonstressed, noncannulated. After stimulation by fMetLeuPhe, production of FOR by ALM and PerM significantly increased after stress and returned to normal values after RU 41740 treatment (p < 0.001). The cytokine levels (TNF-alpha and IL-1alpha) decreased after stress and returned to normal levels after RU 41740 treatment. This study shows that, in aged mice, auditory stress is associated with modifications of macrophage functions which are different, depending on their localization and on the function under study. It confirms the immunomodulatory capacities of RU 41740 that was shown to counteract these effects of stress in elderly animals.

Synthesis of new pyrrolo[1,2-d][1,2,4]triazines and thiazolo[3,4-d][1,2,4]triazines as immunostimulating agents.

Four pyrrolo[1,2-d][1,2,4]triazines and four thiazolo[3,4-d][1,2,4]triazines were synthesized from trans-4-hydroxy-L-proline and L-thiaproline, respectively. The synthetic route involved formation of hydrazides followed by cyclization with orthoesters. The proliferative response to human lymphocyte mitogen (phytohemagglutinin) revealed significant immunostimulant activity for all test drugs. Furthermore, some triazine derivatives were effective to activate production of free oxygen radical by phagocytes in response to stimulation by opsonized zymosan.

Auditory stress induces changes in membrane functions of mouse peritoneal macrophages.

Stressful events induce responses in the endocrine and immune systems. The authors analysed the influence of repetitive noise stress on peritoneal macrophage oxidative and phagocytic responses. Plasma corticosterone levels were also measured. Different groups of 6- to 8-week-old C57BL/6 male mice were exposed for 1 night (n = 14) and 3 nights (n = 21) to a sound stress of 110 dB in an audiogenic stress chamber. Control animals were submitted to a sham stress for 1 night (n = 13) and 3 nights (n = 17). A marked decrease was observed in the phagocytic response to yeast (P = 3 x 10(-4)) while a mild increase in the oxidative response stimulated by opsonized zymosan was noted only after the 3 night stress (P = 0.02). Corticosterone levels of control and stressed mice did not differ. These results indicate that the stress resulting from repetitive noise causes modifications in peritoneal macrophage activity, and that these changes are dependent on the duration of stress. These functional alterations seem more complex than a simple general suppression or activation.

[Study of the membrane oxidative response of phagocytes after treatment with marbofloxacin in healthy cattle]. / Etude de la réponse oxydative membranaire des phagocytes après traitement par la marbofloxacine chez le bovin sain.

In addition to their antibacterial properties, quinolones are capable of modulating the immune response. The aim of this paper was to study the effects of a new fluoro-4-quinolone on the respiratory burst. We evaluated the effects of marbofloxacin on the activation of peripheral phagocytes in non-infected bovines after a 5-day treatment. The immunopharmalogical study measured the chemiluminescence response of phagocytic cells obtained from total blood. Serum cortisol and albumin levels were also measured. Data showed that the treatment with marbofloxacin induced a mild decrease in the oxidative response. There was no significant difference between serum albumin levels of normal values and those of before and after treatment, and the levels of serum cortisol were also not significantly different before and after treatment. These results suggest that marbofloxacin treatment could modulate the inflammatory response of phagocytic cells by counteracting the oxidative burst.

[Value and limitations of anti-mannan antibodies research by co-immunoelectrodiffusion in the diagnosis of deep candidiasis]. / Intérêt et limites de la recherche des anticorps anti-mannane par co-immunoélectrodiffusion dans le diagnostic des candidoses profondes.

Several groups have evaluated detection of antibodies against Candida, with somewhat conflicting results. In this study, co-counterimmunoelectrodiffusion was used to detect antimannan antibodies specific of components of the Candida membrane. Study patients were divided into two groups according to whether their history for Candida infection was negative (population A, n = 102) or positive (population B). Different antigen levels were used in order to differentiate low and high antimannan antibody levels. Among the 102 sera in population A, 42 were positive for antimannan antibodies; the antimannan antibody titer was low in 40 cases and high in 2 cases. In population B (53 patients), antimannan antibodies were found in 97 of the 98 sera studied; titers were high in 95 cases. Use of an antigen level that detects only high titers of antimannan antibodies thus provides a sensitive and specific tool for the diagnosis of deep candidiasis. The simplicity and rapidity of this test are particularly valuable in situations where emergency treatment is needed.