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Biomedical subjects

B Rouveix

Publications and source records attributed to B Rouveix.

At least 55 records · Page 3Linked to original sources
PubMed1986

Diethyldithiocarbamate provides partial protection against pulmonary and lymphoid oxygen toxicity.

Prolonged exposure of C57B16 mice to pure O2 at 1 ATA induced pulmonary edema associated with involution of lymphoid system and depressed immunity. The consequences of these toxic events were evaluated by 1) mortality rate, 2) determination of pulmonary water, 3) thymic and splenic cellularity, and 4) humoral (primary antibodies) and cellular (mitogenic) immune responses. Pretreatment of mice with 125 mg kg-1 of diethyldithiocarbamate (DDC) several days before exposure to O2 resulted in 1) an increase in animal survival (92-100% vs. 59% O2 controls), 2) a reduction in pulmonary edema, 3) partial stabilization of thymus and spleen lymphocyte populations, and 4) restoration of the humoral response (specific antibodies appeared earlier than in O2 control animals) and improvement of the mitogenic proliferative response of the spleen cells after hyperoxia. None of these effects were observed when DDC treatment coincided with the beginning of exposure. Our results indicated that DDC protects mice from both pulmonary and lymphoid hyperoxic injury, but only in a partial manner. It is suggested that the mechanism of this antioxidative property is indirect.

Animals↗
PubMed1986

A comparison of leukocyte aggregation, leukocyte migration and skin reactivity to recall antigens in patients with AIDS.

A study was made to evaluate the leukocyte aggregation test (LAT) in patients at risk for acquired immunodeficiency syndrome (AIDS) and with confirmed AIDS using tuberculin, streptococcus and candida as recall antigens. These patients were selected on the basis of their well known absence of delayed hypersensitivity, a fact which should avoid false positive tests. Antigen-induced human peripheral blood leukocyte aggregation was measured quantitatively. The results obtained have been compared with the leukocyte migration inhibition test (LMIT) in patient and control groups. Among the 46 patients, less than 7% were positive for the LAT, whereas more than 50% were LMIT positive (P less than 0.001). These results suggest that there are fewer false positive reactions with LAT which can therefore be considered as a reliable method for assessing CMI in human. Furthermore, a negative LAT correlated well with negative delayed skin tests in more than 90% of the patients for the three antigens. These patients had either an AIDS or an advanced AIDS-related complex (ARC). In only eight of the patients was there a discrepancy in the results of the two tests. A positive LAT and a negative skin test were seen in three cases lacking opportunistic infections (OI), whereas a negative LAT and a positive skin test were found in patients with or without OI. In the latter, a negative LAT could indicate a more advanced stage of disease and hence a poor prognosis.

AIDS-Related Complex↗
PubMed1985

Evaluation of cellular immune response during chronic schistosomiasis in humans by the leukocyte aggregation test and the leukocyte migration inhibition test.

Cellular immune response was evaluated in 31 patients with chronic Schistosoma haematobium and Schistosoma mansoni infections and in 15 healthy normal persons by using S. mansoni soluble worm and egg antigens. Although the leukocyte migration inhibition test demonstrated false-positive reactions, the specificity of the leukocyte aggregation test was confirmed by the negativity of all of the controls. Among the patients, only 10% were positive for the leukocyte aggregation test. This low cellular reactivity was in contrast to markedly elevated specific humoral response determined by an enzyme-linked immunosorbent assay for immunoglobulin G and paper allergosorbent test for immunoglobulin E with soluble worm antigen. These results confirm that the cellular immune reactivity to schistosome antigen as demonstrated by the leukocyte aggregation test is either minimal or absent in chronically infected patients.

Antigens, Helminth↗
PubMed1985

IgE response and histamine release in chronic human schistosomiasis.

Total and specific IgE anti-schistosome antibodies were quantitated in 31 patients with chronic schistosomiasis and in 15 controls. Both levels of total and specific IgE were significantly increased in sera of 74 and 68% of infected patients respectively. Histamine release from basophils by specific antigens was assessed using a spectrofluorimetric method. This test was found to be highly significant in all the patients studied. There was a significant correlation between specific IgE levels and histamine release (R = 0.43, p less than 0.05).

Adult↗
PubMed1983

Neutropenia due to beta lactamine antibodies.

Neutropenia developed in 13 patients during treatment with beta lactamines. The time of onset ranged from eight to 27 days after beginning treatment and occurred with doses as low as 40 mg/24 hours. Concomitant symptoms were eosinophilia, rashes, and fever. Leucoagglutinins were detected in eight out of nine patients by the microleucoagglutination technique. Clinical and serological findings suggested that neutrophils become sensitised as a result of absorption on the cell membrane of drug-antibody immune complexes. An immune mediated pathogenesis for neutropenia induced by beta lactamine seems highly probable.

Adult↗
PubMed1983

Diagnosis of penicillin allergy. An evaluation of the leucocyte aggregation test in man.

A study was made to establish the value of the leucocyte aggregation test (LAT) in drug allergy using penicillin antigen. The antigen-induced human peripheral blood leucocyte aggregation was measured quantitatively. The results obtained have been compared with the leucocyte migration inhibition test (LMIT) in patients with or without delayed penicillin allergy. Among forty-four penicillin-allergic subjects and thirty-six control subjects, LAT was found positive in respectively 70.5 and 30.5% (P less than 0.001) whereas LMIT was found positive in respectively 56.8 and 50% of the patients. These results were confirmed by multiple correspondence analysis (MCA), using a computer. Furthermore, this method, enables a more comprehensive and reliable interpretation of the tests, by the help of various quantitative and qualitative criteria. It is concluded that LAT shows more discrimination than the LMIT in distinguishing a penicillin-allergic population from a non-allergic one. In addition, LAT offers great technical advantages over the LMIT for the diagnosis of drug allergy.

Adult↗
PubMed1983

[Replacement of the anterior cruciate ligament by carbon fibers. An experimental study].

The authors have excised the anterior cruciate ligament in 14 sheep and replaced it by carbon fibres. The animals were sacrificed after 12 to 18 months. Eight had a satisfactory new ligament without any evidence of arthrosis and with stability of the knee. In 2 cases, there was moderate instability and arthrosis associated with a lax ligament and in 3 cases the new ligament had ruptured with severe instability and arthrosis. Microscopic examination shows a satisfactory acceptance of the carbon filament both inside the bone as well as in the joint. There was no difference between cases repaired immediately or 6 months after excision of the ligament. A study of aortic lymph nodes showed the presence of carbon particles. The rupturing strength of the new ligaments and of normal ligaments were similar. The visco-elasticity of the new ligaments was also studied and was found to be satisfactory. It was considered that the use of carbon fibre may be valuable but more studies should be done to improve the elasticity and to decrease the migration of carbon material.

Animals↗
PubMed1983

Characterization of immunological depression in mice exposed to normobaric oxygen.

Immunological cell functions were evaluated during 24, 48 and 96 h O2 exposure in C57Bl/6 mice. A normobaric O2 exposure resulted in depression of delayed type hypersensitivity (DTH) to oxazolone and Staphylococcus aureus antigens. This effect was proportional to the duration of O2 exposure. The antibody response of splenic cells was more rapidly (24 h O2 exposure) and markedly depressed using a T-dependent antigen (sheep red blood cell, SRBC) than with a T-independent antigen (trinitrophenylated lipopolysaccharide, TNP-LPS). While mitogen-induced proliferative responses of spleen cells to Con A and PHA were inhibited after 72 h of O2 exposure, proliferative responses to LPS were inhibited after 96 h. A dissociated antigen and mitogen responses was observed after a short time of O2 exposure (48 h): the antigen specific responses were impaired with a more pronounced effect on T lymphocytes, whereas the DNA synthesis in response to mitogen remained normal.

Animals↗
PubMed1982

[Leukocyte aggregation test for assessing cell-mediated immunity: its use in drug allergy (author's transl)].

The author has designed a new quantitative leucocyte aggregation test a measure cell-mediated immunity in man. The test involves continuous recording of light absorbance by stirred leucocyte suspensions. Potentially, measurement of direct leucocyte aggregation offers considerable advantages in terms of sensitivity, reproducibility and simplicity of execution. The technique was initially developed in animals and made it possible to assay very small amounts of lymphokines. The results obtained in man with antigenic drugs, such as penicillin, confirm that the aggregation test is much more sensitive than the migration inhibition test. Its precise significance remains uncertain, but it already promises to constitute a simple and highly reliable means of diagnosing and preventing drug hypersensitivity.

Animals↗
PubMed1981

Lymphokine-induced macrophage aggregation: involvement of cyclic-GMP and microtubules.

Human lymphokine (LK) is known to induce guinea pig macrophage aggregation. This effect can be quantitatively measured with a Born modified platelet aggregometer. This method has been well correlated with the state of delayed hypersensitivity. Previous findings about the mechanism of action of the aggregation indicated that this aggregation is not due to an increase in the cellular level of c-AMP. It is doubtful whether c-AMP is a messenger of the LK action. Using a radio-immunoassay, small but significant increases were found in c-GMP levels of LK-aggregated macrophages. In addition, exogenous dibutyryl c-GMP and carbamylcholine induced a macrophage aggregation, as did the divalent cation ionophore A-23187. These data, together with the fact that LK-induced macrophage aggregation is inhibited by colchicine and at 0 degree C, suggest that microtubule polymerization is involved in this process.

Calcium↗
PubMed1981

Absorption of macrophage aggregating factor by guinea-pig peritoneal exudate cells.

Lymphokine (LK)-induced aggregation of peritoneal exudate cells (PEC) has been measured using a quantitative technique. Aggregating activity could be removed from LK preparations by absorption of these with PEC and, in addition, the absorbing PEC, on further incubation themselves aggregated. Absorption of aggregating activity to PEC was rapid, being easily measurable at between 2-5 and 10 min although it was difficult to demonstrate at 30 min. Trypsinized PEC were as effective as normal PEC in absorbing aggregating activity. alpha-L-fucose inhibited LK-induced PEC aggregation and this inhibition showed some specificity in being significantly greater than that obtained with D(+)galactose. However, measurement of the subsequent aggregation of PEC which had been pulse exposed to LK, in the presence of alpha-L-fucose, showed that alpha-L-fucose had no effect on this aggregation. It is concluded that the measurement of aggregating activity can be used to study LK binding to PEC, although the relationship of this binding to the inhibition of aggregation obtained with alpha-L-fucose is not clear.

Animals↗
PubMed1980

Lymphokine-induced Macrophage aggregation: the possible role of cyclic nucleotides.

The possible role of cyclic nucleotides in guinea pig macrophage aggregation, induced by human lymphokine (LK) has been investigated. Small increases were found in guanosine 3'5'-cyclic monophosphate (cGMP), but not adenosine 3'5'-cyclic monophosphate (cAMP), levels of lymphokine aggregated macrophages. Addition of exogenous dibutyryl (DB) cAMP, L-isoproterenol, or theophylline did not induce macrophage aggregation. By contrast, both exogenous DBcGMP and carbamyl-choline induced a macrophage aggregation; although DBcGMP was more effective. In addition, both L-isoproterenol and DBcAMP in the presence of theophylline decreased LK-induced macrophage aggregation, whereas D-isoproterenol and DBcGMP had no effect. The results obtained here are discussed in the context of the previously reported effects of cyclic nucleotides on migration inhibitory factor (MIF) activity and the possible role of these agents in the mechanism of action of MIF.

Bucladesine↗
PubMed1980

Studies on lymphokine-induced macrophage aggregation. Specificity and quantitative aspects.

A method for the quantitative measurement of macrophage aggregation by lymphokine preparations has been described previously. This involved the continuous measurement of the light absorbance of stirred suspensions of guinea pig peritoneal exudate cells (PEC). We now show that using a modified method, both aggregation of normal PEC, induced by preformed lymphokine, and direct aggregation of sensitized PEC with specific antigen can be measured. The method is suitable for the assay of large numbers of samples. Aggregation is shown to be immunologically specific for two antigens (bovine gamma-globulin and ovalbumin) and to be partially inhibited by sugars which inhibit migration inhibitory factor activity (rhamnose and fucose).

Animals↗
PubMed1979

Studies on the mechanism of macrophage aggregation induced by lymphokines.

Macrophage aggregation (measured by a light-scattering technique) induced by unpurified lymphokine preparations has been investigated. This has been shown to be Ca2+ or Mg2+ dependent and to be inhibited by a number of agents known to affect cellular physiology and biochemistry. The divalent cation ionophore A23187 causes a macrophage aggregation superficially similar to that induced by lymphokines, although differences were found. It is suggested that a biochemical response by the macrophage is required for aggregation induced by lymphokines, and thus measurements of macrophage aggregation allow a study of the early events in the response of macrophages to lymphokines.

Animals↗
PubMed1979

A sensitive technique for measuring specific macrophage aggregation: a comparison with macrophage migration inhibition, for the detection of lymphokine activity.

A new quantitative method for the measurement of macrophage aggregation, induced by lymphokine preparations, is described. This involves the continuous measurement of the light absorbance of stirred macrophage suspensions. The results have been compared with those obtained by measuring macrophage migration inhibition activity for the detection of lymphokine activity. Separation of crude lymphocyte culture supernatants by Sephadex G-200 shows that the material with aggregating activity is heterogeneous. The greater amount of this activity is not separated from macrophage migration inhibition activity, and has a molecular weight of 35,000--70,000. A comparison has been made with other published methods for measuring macrophage aggregation.

Cell Aggregation↗