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Biomedical subjects

C Benezra

Publications and source records attributed to C Benezra.

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

Allergic contact dermatitis to garlic (Allium sativum L.). Identification of the allergens: the role of mono-, di-, and trisulfides present in garlic. A comparative study in man and animal (guinea-pig).

Garlic (Allium sativum L.) water- and ethanol-soluble extracts were prepared and purified by column chromatography. They were tested on garlic-sensitive patients and showed that the allergenic fraction was well located in a few column chromatography fractions. Guinea-pigs were sensitized with garlic water-soluble extracts and tested (open epicutaneous tests) with several fractions. The presence of diallyldisulfide was detected in the sensitizing chromatographic fractions. Guinea-pigs were successfully sensitized to this product and cross-reacted to garlic; animals sensitized to garlic extracts cross-reacted to diallyldisulfide. Both groups reacted to allicin, an oxidized derivative of diallyldisulfide present in garlic. Garlic-sensitive patients showed positive tests to diallyldisulfide, allylpropyldisulfide, allylmercaptan and allicin.

Allergens↗
PubMed1983

The influence of limonene on induced delayed hypersensitivity to citral in guinea pigs. II. Label distribution in the skin of 14C-labelled citral.

14C-labelled citral was applied on four groups of guinea pigs: (a) one sensitized to citral alone; (b) one sensitized to a citral-d-limonene 1 : 1 molar mixture; (c) FCA-treated controls; (d) controls. The most important results concern the amount of labelled material in soluble compared with insoluble skin protein extracts (SPE). In citral-sensitized animals, more label was found in the soluble SPE when citral + limonene was applied to the skin; in citral + limonene sensitized animals, the same trend (i.e. more label in soluble SPE) was found. The possible role of limonene in alleviating the allergic reaction to citral is discussed.

Acyclic Monoterpenes↗
PubMed1982

Stereospecificity of allergic contact dermatitis (ACD) to enantiomers. Part III. experimentally induced ACD to a natural sesquiterpene dialdehyde, polygodial in guinea pigs.

Guinea pigs were sensitized to polygodial 1, a natural sesquiterpene dialdehyde, using intradermal injections in Freund's complete adjuvant. Cross-reactions with a (+/-)-mixture of warburganal and (-)-warburganal 2 (a natural hydroxylated derivative of polygodial) showed a high specificity of the allergic response since the (-)-pseudoenantiomer (having the same configuration as the primary sensitizer) gave a stronger skin reaction than the racemic mixture.

Allergens↗
PubMed1982

Allergic contact dermatitis to methylenelactones. Use of lymphocyte transformation test.

Seventeen guinea pigs were sensitized to alantolactone, a natural sesquiterpene lactone known for its sensitizing properties, using intradermal injections in Freund's complete adjuvant. Guinea pig skin protein extracts (SPE) were used to make conjugates with alantolactone and an isomer, isoalantolactone. Lymphocyte blastogenesis was observed with SPE-alantolactone conjugates, as well as with guinea pig albumin-lactone conjugates. In six cases, stimulation was noted with unconjugated haptens. These results do not show a high degree of hapten-carrier specificity in contact sensitivity to alantolactone, induced by unconjugated hapten injections. Cross-sensitivity with SPE-isoalantolactone conjugate was also observed.

Allergens↗
PubMed1982

Double-head haptens. Synthesis of and experimentally induced contact sensitivity to substances containing two unrelated haptens, pyrocatechol and alpha-methylene-gamma-butyrolactone, in the same molecule.

A "double-head" hapten containing a pyrocatechol and an alpha-methylene-gamma-butyrolactone moiety (3) and "monofunctional haptens" with either one of these moieties (18 and 19) connected by a six-carbon chain have been synthesized, and their sensitizing capacity was tested on guinea pigs. In the "double-head" hapten, only the pyrocatechol end is "recognized". A possible interpretation of the biological results is offered.

4-Butyrolactone↗
PubMed1982

Allergenic alpha-methylene-gamma-butyrolactones. Stereospecific syntheses of (+)- and (-)-gamma-methyl-alpha-methylene-gamma-butyrolactones. A study of the specificity of (+) and (-) enantiomers in inducing allergic contact dermatitis.

The enantiomers of gamma-methyl-alpha-methylene-gamma-butyrolactone have been prepared stereospecifically from (R)- and (S)-glutamic acid. Three groups of guinea pigs have been sensitized (Feund complete adjuvant technique) to the (+) isomer, the (-) isomer, and the (+/-) mixture. The animals have been tested with each of the enantiomers and with a mixture of the compounds. Only the (-) enantiomer showed some specificity: guinea pigs sensitized to this enantiomer react weakly to the other compound; in turn, animals sensitized to the (+) enantiomer react similarly to both antipodes. Interestingly, reaction to the (+/-) mixture in each group of guinea pigs was the sum of skin responses to the individual enantiomer. These results should be contrasted with sensitization to (+)- and (-)-frullanolides, sesquiterpene lactones for which strong stereospecificity was observed.

4-Butyrolactone↗
PubMed1982

Mediastinal abscess secondary to vertebral osteomyelitis.

A 29-year-old man with complaints of pain in the low back, both flanks, and midepigastrium was found to have vertebral osteomyelitis. Mediastinal abscess was also diagnosed on the basis of findings on chest x-ray film, thoracic ultrasonography, thoracentesis, and cultures of pleural fluid. Antibiotic therapy was begun, and open drainage with rib resection was performed. After six weeks of treatment, the patient was free of symptoms. We believe this is the first report of mediastinal abscess secondary to vertebral osteomyelitis in an adult since the advent of antibiotics.

Abscess↗
PubMed1981

Allergic contact dermatitis to costus: removal of haptens with polymers.

Costus oil, an iol isolated from a Composite, Saussurea lappa C., used in perfumery, is responsible of numerous cases of allergic contact dermatitis (ACD). The haptens incriminated are sesquiterpene lactones, costunolide and dehydrocostuslactone. These lactones can be removed from the oil by using a polymer, aminoethyl-polystyrene, to which they become bound: the passing solution is lactone-free. A group of guinea-pigs could be successfully sensitized (Freund Complete Adjuvant Test) to costus essential oil, while another group, injected in the same way with polymer-treated essential oil (i.e. lactones) could not be sensitized. This polymer therefore provides a means to render complex plant extracts non-allergic.

Animals↗
PubMed1980

Synthesis of alpha-methylene-gamma-butyrolactones: a structure-activity relationship study of their allergenic power.

Thirty-five alpha-methylene-gamma-butyrolactones have been prepared and their allergenic properties tested on the skin of guinea pigs experimentally sensitized to (a) alantolactone (1), (b) isoalantolactone (2), and (c) alpha-methylene-gamma-butyrolactone (3). The two first groups of animals cross-react to lactones containing 9 to 18 carbon atoms but not to smaller alpha-methylene-gamma-butyrolactones. Conversely, animals sensitized to alpha-methylene-gamma-butyrolactone react only with alpha-methylene-gamma-butyrolactones containing 6 and 7 carbon atoms. These results are discussed in relation with the allergic contact dermatitis mechanism.

4-Butyrolactone↗
PubMed1980

Eau de Javel and prevention of chromate allergy in France.

"Eau de Javel" (liquid bleach) is a common cause of chromate contact allergy. A historical review explains the reasons for the addition of sodium dichromate after the First World War. The chromium content in different brands of eau de Javel has been determined by flameless atomic absorption spectrophotometry. The results indicate that the chromium content is very low (0.03--3.65 mg/l) in French brands, whereas it is still important (7.06--82.9 mg/l) in Belgian brands, such an observation indicates that the almost complete removal of chromate in most brands of French eaux de Javel is a good example of prevention in the field of contact dermato-alllergology.

Belgium↗
PubMed1978

Allergic contact dermatitis due to sesquiterpene lactones. A comparative study of human and animal sensitivity to alpha-methylene-gamma-butyrolactone and derivatives.

Several compounds containing the alpha-methylene-gamma-butyrolactone moiety have been tested on human volunteers and on guinea-pigs; the animals were experimentally sensitized by alantolactone, isoalantolactone and laurel oil. Of the two new lactones, spirolactone was the more reactive: this was confirmed by both animal and human testing. The synthetic lactones are less reactive than natural ones. alpha-Methylene-gamma-butyrolactone itself does not elicit cross-reactions in guinea pigs sensitive either to alantolactone or to isoalantolactone, or in patients sensitive to sesquiterpene lactones. The alpha-methylene-gamma-butyrolactone group is necessary for cross-reaction, but to be active, it has first to be substituted. It was also found that isoalantolactone, allegedly not allergenic, is in fact a sensitizer and cross-reacts with alantolactone. The cross-reaction between laurel and Frullania, found in man, also occurs in guinea-pigs. It is more evident when sesquiterpene lactone is the sensitizer and laurel used to elicit reaction.

4-Butyrolactone↗
PubMed1978

Concentrations of patch test allergens: are we comparing the same things?

A new way of expressing the concentrations of patch test allergens solutions (or emulsions) is proposed. From these new expressions it can be seen that apparently similar concentrations (0.5% chromium, 2% formaldehyde) can actually be in the ratio 1 to 15 as expressed at the molecular level.

Allergens↗