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Biomedical subjects

B Lebel

Publications and source records attributed to B Lebel.

At least 55 records · Page 3Linked to original sources
PubMed1983

Biologic properties of homogeneous interleukin 3. I. Demonstration of WEHI-3 growth factor activity, mast cell growth factor activity, p cell-stimulating factor activity, colony-stimulating factor activity, and histamine-producing cell-stimulating factor activity.

Interleukin 3 (IL 3) was initially defined as a factor in conditioned media from concanavalin A-stimulated lymphocytes (Con A CM) that induces the enzyme 20-alpha-hydroxysteroid dehydrogenase (20 alpha SDH) in cultures of nu/nu splenic lymphocytes. To determine the spectrum of additional "biologic" activities, IL 3 was purified to homogeneity and its properties were assessed. The protein preparation was judged to be homogeneous IL 3 by the following criteria: 1) elution of a peak of IL 3 with a constant specific activity in the last step of purification, 2) presence of a single protein by SDS-PAGE analysis, 3) receptor-binding activity against IL 3-dependent cell lines, 4) a specific activity of congruent to 0.2 ng/ml required for 50% of maximal biologic activity, and 5) the presence of a single amino terminal sequence. With the use of this preparation of IL 3, the dose-response curves for 20 alpha SDH induction were identical or similar to the dose-response curves for the activities of 1) WEHI-3 growth factor, 2) mast cell growth factor, 3) P cell-stimulating factor, and 4) histamine-producing cell-stimulating factor. In addition, homogeneous IL 3 had colony-stimulating factor activity, although only approximately 2% of the total CSF activity found in Con A CM was associated with IL 3. The major peak of CSF activity could be resolved from IL 3 by DEAE column chromatography and lacked many of the biologic activities associated with IL 3.

Animals↗
PubMed1981

[Production of histamine and histamine-producing cell stimulating factor (HCSF) by leukocytes incubated with concanavalin A. Effect of presensitization by a skin allograft].

The production of histamine is increased during Con A stimulation of normal spleen cells. This phenomenon results from the action of a factor released by stimulated lymphocytes. The factor is probably HCSF (Histamine-producing Cell Stimulating Factor) that we have previously described in supernatants of mixed lymphocyte culture.

Animals↗
PubMed1981

Histamine production during the anti-allograft response. Demonstration of a new lymphokine enhancing histamine synthesis.

Histamine production is greatly increased during culture of allograft recipient spleen cells in the presence of immunizing cells (secondary mixed leukocyte cultures [MLC]) as compared to that found in primary MLC (i.e., without previous allograft). This phenomenon appears after 24 h of culture and reaches its maximum at 48 h. Optimal increased histamine production is observed when MLC is performed with spleen cells removed from mice during rejection. This increased production of histamine during secondary MLC results from the action of a lymphokine: the histamine-producing cell stimulating factor (HCSF). This factor is released by T lymphocytes. Its production requires specific stimulation of the recipient lymphocytes because increase in histamine production during secondary MLC can be only observed when recipient cells are cultured with stimulating cells bearing at least one homology at K or D loci with immunizing cells. HCSF acts on a cell which is present in bone marrow, spleen, blood, and peritoneal cells but absent in thymus or lymph node cells. This target cell is found in the less-dense layer of a discontinuous Ficoll-gradient of bone marrow cells. HCSF is heat stable, destroyed by trypsin treatment, and has a molecular weight between 50,000 and 100,000. It acts on its target cells by increasing histidine decarboxylase activity.

Animals↗
PubMed1981

Histamine-releasing properties of hydroxy-9-methyl-2-ellipticinium acetate.

Previous work on Hydroxy-9-methyl-2-ellipticinium acetate indicated a bronchoconstrictor activity which could be partially offset by antagonists of the H1 histamine receptors, and the absence of any direct effect on smooth muscle. OH-9-CH3-2-E at concentrations of 10 micrograms/ml and 500 micrograms/ml produced a moderate and a variable release of histamine when placed in contract with whole human blood and lung fragments, respectively. In addition, at a dose of 3 mg/kg in the guinea pig, pulmonary airway resistance was raised and the blood histamine level lowered. A significant correlation was found between these two effects. These results demonstrate that OH-9-CH3-2-E possesses a histamine-releasing potency which is partly responsible for its bronchial effects, implying that precautions may have to be taken when it is used as a therapeutic agent in sensitive subjects. However, the moderate intensity of this potency has not so far precluded therapeutic use of the preparation.

Airway Resistance↗
PubMed1981

In vitro influence of theophylline on anti-IgE-induced release from leucocytes and whole blood in asthmatic children.

Two groups of asthmatic children were found with regard to the influence of theophylline on the anti-IgE-induced histamine release from whole blood. In th first group (21 children), histamine release was obtained both from whole blood and washed leucocytes and was inhibited by 10(-4) M theophylline. In the second group (5 children), histamine release required the presence of plasma and was not inhibited by 10(-4) M theophylline. Theophylline treatment was efficacious only in children of the first group.

Adolescent↗
PubMed1981

Increased tissue histamine in tumour-bearing mice and rats.

Tissue histamine levels were studied in C3H and C57BL/6 mice bearing a methylcholanthrene-induced fibrosarcoma, in Wag rats bearing an aflatoxin B1-induced hepatoma, and in Commentry rats bearing a grafted hepatoma. Histamine levels were significantly higher (1.5 to 3 fold) in the tumour-bearing animals for ventral and dorsal skin, skeletal muscle and stomach fundus. Total histamine content was increased in the spleen. In C3H mice with McC3-1 fibrosarcoma, the excision of the tumour or its partial regression by intratumoral injections of corynebacterium parvum induced a reversion to normal values. The tumour thus appears responsible for the increased histamine levels in tissues distant from the tumour.

Animals↗
PubMed1981

Changes in histamine and white blood cells in the blood, spleen and thymus of magnesium-deficient rat.

Groups of rats were given either a control or a magnesium-deficient diet. The well-known allergy-like crisis, characterized by vasodilatation with redness of the ears and dermatosis, occurred spontaneously in the magnesium-deficient groups. The histamine (H) content and the distribution of the various white blood cells (WBC) were studied as a function of time. During the acute phase, there was a transitory elevation of total blood H and WBC, mainly affecting the polymorphonuclear (PMN) cells, eosinophils (EO) and basophils (BAS). The EO peak preceded that of H. The EO count was especially high during the first part of the acute phase, while H and BAS were higher during the second part of that phase. There were no BAS's in the blood of the controls and those in the Mg-deficient animals were only partly granulated. H, EO and mast cells (MC) were elevated in the spleen but not in the thymus during acute deficiency. The high H level in the spleen corresponded to the same high level in the blood. When the spleen suspensions were centrifuged, wide differences in supernatant and pellet histamine appeared, according to the deficiency period.

Animals↗
PubMed1980

Influence of histamine or dimaprit on histamine release induced by anti-ige from human whole blood.

In human subjects histamine release from whole blood by anti-IgE and studied under several concentrations of histamine and dimaprit. The results obtained in our experiments led us to question the autoregulatory feed-back mechanism postulated by BOURNE et al. [1]. Apparently this mechanism does not apply for all patients particularly at doses which resemble physiological concentrations of histamine.

Antibodies↗
PubMed1980

Histamine levels in mouse tissues of different strains: influence of sex.

The sex related difference in histamine levels of various mouse tissues was investigated in several mouse strains. In all of them the histamine levels were higher in female animals than in males. Thus experiments on histamine in mice must be carried out in animals matched for sex and strain.

Animals↗
PubMed1980

Histamine levels in mouse tissues: influence of castration.

The influence of castration on histamine levels in mouse tissues was investigated in Swiss mice. Only in female mice castration led to a significant decrease in the histamine content of dorsal and ventral skin, skeletal muscle and kidney. This effect was found 2 weeks after castration. A long-term study is being presently undertaken.

Animals↗
PubMed1980

Studies on Dermatophagoides pteronyssinus allergens: measurement of the relative potencies of D. pteronyssinus purified extracts by in vitro and in vivo methods.

To standardize the Dermatophagoides pteronyssinus extracts used in clinical allergy practice, the relative potencies of several purified extracts were estimated by radioallergosorbent test (RAST) inhibition, histamine release, and intracutaneous titration testing, and the results were compared. The potencies of nine independently prepared D. pteronyssinus extracts were assayed with respect to an extract adopted as a reference. In vivo the cutaneous wheal surface after intradermal injections was measured on a population of D. pteronyssinus-sensitive subjects. In vitro RAST inhibition was performed with the reference extract as allergosorbent and with a pool of human IgE-rich sera from patients sensitized to D. pteronyssinus but untreated. For histamine release human basophils from patients allergic to D. pteronyssinus were used. In the three method dose-response curves were plotted for the reference extract and the other extracts. A comparison of the measurement of in vitro and in vivo potencies is reported. Simialr results were obtained with the three methods: all the extracts but one were as potent as the reference preparation. However, for routine purposes RAST inhibition appears to be the most convenient and reliable procedure.

Allergens↗
PubMed1980

Aromatic amines (serotonin and histamine) and magnesium deficiency in the rat.

Rats were made deficient by giving a 4 mg Mg/100 g diet. The control diet content was 40 mg Mg/100 g. Serotonin injected to magnesium deficient and control rats was metabolized at the same rate in both groups and the urinary derivatives were similar. Serotonin catabolism can occur in liver as shown by isolated hepatocyte technique. Hyperemia of the ears and dermatosis appeared in magnesium deficient rats, while histaminemia rised. This allergy-like crisis was delayed and milder, when the food intake was reduced. The evolution of histaminemia was studied in parallel with the different white blood cells, during three periods of magnesium deficiency. An important rise of total white blood cells, specially poly morphonuclear and eosinophil cells was observed. The peak for eosinophils occured before the histaminemia and basophils peaks. Basophils cells found only in magnesium deficient group were partly degranualted.

Animals↗
PubMed1980

Magnesium deficiency allergy-like crisis in hairless rats: a suggested model for inflammation studies.

Two groups of rats, one hairy and one hairless, received either a magnesium deficient diet (4 mg Mg/100 g diet) or a control diet (40 mg/100 g diet). After four days, an easily observable redness of the skin occurred in the hairless deficient group, progressing from the tail to the forehead, and later a hyperemia of the ear and dermatosis which increased with scratching appeared in both deficient groups. The clinical signs were more acute in the deficient hairless group. Histamine, total white blood cells and eosinophil counts increased in both deficient groups during the allergy-like crisis. Then, these factors tended to normal values. After three weeks on a diet an enlargement of the spleens was observed, but not of the thymus in both deficient groups. There was a large difference in the histamine content of the spleen between the deficient and control hairless groups: the values obtained were 4 350 ng and 166 ng per 100 g tissue respectively.

Animals↗
PubMed1980

[Histamine receptor bearing mononuclear cells in children with atopic dermatitis (author's transl)].

The frequency of mononuclear cells bearing membrane receptors for histamine was investigated in peripheral blood from children with atopic dermatitis (AD) by means of the rosettes histamine assay, using sheep erythrocytes coated with histamine. Histamine rosettes (HR) varied from 5.70 to 11.25 p. 100 in healthy adults; from 3.25 to 7.75 p. 100 in control children and from 2 to 6.55 p. 100 in children with AD. The reaction was specific as histidine and tryptamine only slightly inhibited HR formation, whereas free histamine, histamine H1 and H2 antagonists (neo antergan and metiamide) and the histamine H1 agonist (dimaprit) reduced HR formation much more strongly. The inhibition of the HR formation by all these agents was not found to be significantly different in normal children and in children with AD. However the reduction of the HR formation by a previous incubation with histamine was not constant in children with AD.

Adolescent↗
PubMed1979

[Blood histamine and response of spleen cells to phytohemagglutinins during moderate magnesium deficiency in the rat].

Blood histamine and spleen cell stimulation index by PHA were determined in either magnesium deficient or control Rats. Between the 10th and 17th days of diet (hyperemia and dermatosis period), histaminemia was significantly higher in deficient animals (485 ng/ml) than in control ones (112 ng/ml), but at the 32nd day it came back to normal values. The mean spleen cell stimulation index by PHA was depressed in deficient animals mainly between the 10th and 17th day of the deficiency; 33% of control mean value. A negative correlation is found between histamine level and stimulation index.

Animals↗