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Biomedical subjects

A Rivier

Publications and source records attributed to A Rivier.

14 recordsLinked to original sources
PubMed1995

Blood monocytes of untreated asthmatics exhibit some features of tissue macrophages.

Airway macrophages are activated in asthmatic subjects. Peripheral blood monocytes from these subjects present some functional features of activation, but their membrane markers are not known. Recently a new subtype of blood monocytes, CD14+/CD16+, has been identified which possesses the characteristics of tissue macrophages. A study was carried out on nine normal subjects and 11 untreated asthmatics having variable severities of the disease to examine the phenotypic characteristics of monocytes. CD14, CD16, HLA-DR, CD11a, CD11b, CD44 and CD54 were studied using double fluorescence flow cytometry since these antigens have been defined in the CD14+/CD16+ monocytes. The functional activation of monocytes was examined using the release of superoxide anion. The co-expression of CD14 and CD16 by monocytes in terms of percentage and mean fluorescence intensity was significantly higher in asthmatics (P < 0.002 and P < 0.0001, respectively, Mann-Whitney U-test). There was no difference for the other membrane markers between asthmatics and normal subjects. Superoxide anion release was significantly increased in asthmatic subjects (P < 0.01). This study shows that most blood monocytes of asthmatics are CD14+/CD16+ and are likely to present features of tissue macrophages.

Adult↗
PubMed1994

Release of cytokines by blood monocytes during strenuous exercise.

During strenuous exercise in endurance athletes, monocytes are activated and there is an acute inflammation and hypoxemia possibly due to lesional pulmonary edema. IL-6 and TNF-alpha released by monocytes may be implicated in the acute phase of lesional pulmonary edema. A study was carried out to determine whether TNF-alpha and IL-6 are released during strenuous exercise, and, if adrenalin released during exercise alters their generation. Ten young and six master athletes underwent an incremental exercise test. Arterial blood was drawn at rest, at the end of the exercise, and 20 minutes afterwards. Monocytes were isolated and incubated for 18 hours in the presence or absence of adrenalin. Il-6 and TNF-alpha were measured in monocyte supernatants. The spontaneous release of IL-6 or TNF-alpha was increased in young athletes when compared to older subjects. The spontaneous release of TNF-alpha was increased, but not significantly, by exercise and there was no correlation between the release of IL-6 and TNF-alpha and lung function measured during hypoxemia. Adrenalin inhibited the release of IL-6 or TNF-alpha. Correlations were observed between the in vitro release of IL-6 or TNF-alpha and age, VO2max, maximal ventilation and maximal power output of the subjects.

Adult↗
PubMed1994

Modulation of phenotypic and functional properties of normal human mononuclear phagocytes by granulocyte-macrophage colony-stimulating factor.

In asthma, alveolar macrophages (AMs) are hyperreactive releasing large amounts of mediators and expressing high levels of surface markers. Granulocyte-macrophage colony-stimulating factor (GM-CSF) upregulates monocytes and AMs, and may be involved in the hyperreactivity of AMs. The effects of GM-CSF were tested on monocytes and AMs from normal subjects by examining the expression of factors thought to be upregulated in asthma. After various incubation times of GM-CSF, the expression of CD23 and beta 2-integrins (CD11a, CD11b, CD11c) was studied by FACS and the release of sCD23 was measured by ELISA. The priming and stimulatory effects of GM-CSF were tested on monocytes and AMs and the release of leukotriene B4 (LTB4) was measured by ELISA. GM-CSF induced the expression of CD11c and CD23 and the release of sCD23. GM-CSF primed and stimulated monocytes and AMs to release LTB4. The effects of GM-CSF may explain partly the hyperreactivity of AMs in asthma.

Adult↗
PubMed1994

Differences in IL-4 release by PBMC are related with heterogeneity of atopy.

Atopy is heterogeneous and the IgE immune response of patients allergic to a single allergen (monosensitized) differs from that of those allergic to multiple allergens (polysensitized). Since interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) regulate human IgE synthesis in vitro, we determined whether cytokines may be involved in the heterogeneity of atopy by comparing the serum IgE and sCD23 titres to the cytokine profile of T lymphocytes from 44 atopic patients (13 mono- and 31 polysensitized) and seven non-atopic subjects. Monosensitized patients were allergic to grass or cypress pollens or house dust mites, and polysensitized ones to many pollen species (n = 5) or many allergens (n = 26). Total serum IgE was lower in the control group than in both atopic groups and in the monosensitized group than in the polysensitized one. IgE immunoblots to orchard grass pollen and house dust mites were less heterogeneous in the monosensitized group than in the polysensitized one. IL-4 production by in vitro-activated peripheral blood mononuclear cells (PBMC) was significantly higher in the polysensitized group than in the monosensitized, and marginal in the control group. In contrast, IFN-gamma production was strongly reduced in both atopic groups, and IL-2 production comparable in the three groups. IgE and soluble CD23 (sCD23) release was higher in the atopic groups than in the control, and higher in the polysensitized group than in the monosensitized one. This study shows that PBMC of mono- and polysensitized subjects have a different IL-4 and sCD23 profile and suggests that human beings may be classified into high and low IgE responders on the basis of IL-4 production.

Adolescent↗
PubMed1975

[Systematic study of sequential salivary gland scintigraphy during rheumatoid arthritis and collagenosis. Apropos of 150 examinations].

Sequential salivary scintigraphy has been practised systematically in 130 patients hospitalized in a rheumatology unit. These patients were suffering from typical, classical rheumatoid arthritis, rheumatoid arthritis with high positivity for anti-nuclear antibodies, clearly defined polyarthritis, systemic scleroderma, other types of collagenosis, forms of inflammatory polyarticular rheumatism other than rheumatoid arthritis and collagenosis, and from different degenerative diseases. The scintigraphic anomalies were divided in three stages according to a personal classification. Nine patients presented a patend Gougerot-Sjögren syndrome. All of them had abnormal or very abnormal scintigraphy. However, the patients with classical rheumatoid arthritis without signs of the Gougerot-Sjögren syndrome, also showed a high frequency of isotopic anomalies that were equally severe. These were clearly connected only with the particular diagnosis (with classical rheumatoid arthritis, but not with clearly defined polyarthritis or collagenosis). No other direct relationship could be established between these diseases and the clinical, radiological, laboratory, or therapeutic aspects of the case. On the other hand, they were often associated with a reduction in lacrymal and salivary secretion. These isotopic studies, in combination with other findings shed a new light on the Gougerot-Sjögren syndrome, taking into account the diffusion of the exocrine lesions and of the contributions of the most modern methods of investigation.

Antibodies, Antinuclear↗