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Biomedical subjects

G Gay

Publications and source records attributed to G Gay.

At least 19 recordsLinked to original sources
PubMed2001

Fungal auxin overproduction affects the anatomy of Hebeloma cylindrosporum-Pinus pinaster ectomycorrhizas.

We studied the effect of fungal auxin overproduction on the growth polarity of cortical cells in pine mycorrhizas by comparing the anatomy of Pinus pinaster (Ait.) Sol. mycorrhizas formed by an IAA-overproducing mutant of Hebeloma cylindrosporum Romagnesi or by the corresponding wild type with non-mycorrhizal short roots. Both wild- type and mutant strains induced an increase in root diameter that was mostly a result of the influence of the fungus on root cortical development. Both strains affected growth polarity of P. pinaster cortical cells and induced a change in their shape. The main modifications were a large reduction in axial diameter and an increase in the radial diameter of the cortical cells. The modifications were more marked with the mutant than with the wild type. The mutant induced a 43% reduction in cortical cell elongation and a 35% increase in radial diameter, whereas the corresponding changes induced by the wild type were 30 and 10%, respectively. The volume of cortical cells in mature mycorrhizas was generally lower than in uninoculated short roots indicating that wild-type and mutant strains induced a reorientation of cortical cell growth but did not induce an increase in turgor pressure of the cells. Immunolocalization allowed visualization of alpha-tubulin in root cortical cells, but no obvious modification in alpha-tubulin distribution was detected as a consequence of symbiosis establishment. Likewise, cytochemical localization of polysaccharides in cortical cell walls did not show significant modification following symbiosis establishment and Hartig net formation. The only noticeable modification was a reduction in cortical cell wall thickness in mycorrhizas compared with uninoculated short roots. The possible involvement of fungal auxin in the observed modifications is discussed.

Basidiomycota↗
PubMed2001

[Fatal anaphylaxis after eating wild boar meat in a patient with pork-cat syndrome].

Crossed allergy between pork and cat epithelia was described by us in 1994. It is due to serum albumin. Nowadays, other bio-chemical observations allow "completion" of the syndrome by extension of the crossed reactivity between other mammal meats and other epithelia of dog and horse. The authors report an observation of the pork-cat syndrome (developing in the form of anaphylaxis, and then ending in the death of the patient), following consumption of wild boar meat. Co-factors, such as effort, taking alcohol or hormonal condition may complicate the picture to make diagnosis more difficult.

Adult↗
PubMed2000

Transcription of a nitrate reductase gene isolated from the symbiotic basidiomycete fungus Hebeloma cylindrosporum does not require induction by nitrate.

Ectomycorrhizal fungi contribute to the nitrogen nutrition of their host plants, but no information is available on the molecular control of their nitrogen metabolism. The cloning and pattern of transcriptional regulation of two nitrite reductase genes of the symbiotic basidiomycete Hebeloma cylindrosporum are presented. The genomic copy of one of these genes (nar1) was entirely sequenced; the coding region is interrupted by 12 introns. The nar1 gene, which is transcribed and codes for a putative 908-amino acid polypeptide complemented nitrate reductase-deficient mutants of H. cylindrosporum upon transformation, thus demonstrating that the gene is functional. The second gene (nar2), for which no mRNA transcripts were detected, is considered to be an ancestral, non-functional duplication of nar1. In a 462-nt partial sequence of nar2 two introns were identified at positions identical to those of introns 8 and 9 of nar1, although their respective nucleotide sequences were highly divergent; the exon sequences were much more conserved. In wild-type strains, transcription of nar1 is repressed in the presence of a high concentration of ammonium. High levels of transcription are observed in the presence of either very low nitrogen concentrations or high concentrations of nitrate or organic N sources such as urea, glycine or serine. This indicates that in H. cylindrosporum, in contrast to all nitrophilous organisms studied so far, an exogenous supply of nitrate is not required to induce transcription of a nitrate reductase gene. In contrast, repression by ammonium suggests the existence of a wide-domain regulatory gene, as already characterized in ascomycete species.

Agaricales↗
PubMed1999

Comparison among 18 hexyl esters of 1-naphthylacetic acid used on grapevine.

Eighteen esters derived from 1-naphthylacetic acid (NAA) and from hexyl isomer alcohols were synthesized and sprayed on grapevine suckers at 1, 2, 4, and 8% w/w concentrations to test their sucker control efficiency 2, 10, and 30 days and 1 year after their application. All compounds gave a prompt control of suckers. After 1 year, sucker growth was inhibited by the derivatives from primary and secondary alcohols, whereas the number of suckers was reduced only by application of naphthyl acetates of tertiary alcohols.

Drug Design↗
PubMed1999

[Chronic urticaria caused by cow's milk allergy: immediate or delayed allergy? (apropos of a case)].

Chronic urticaria has multiple etiologies, amongst them food allergy, which is not the most frequent. We report a clinical case of chronic urticaria due to cow milk, where paradoxically the responsibility of the food was shown by an epidermo test when the prick test was negative. Development confirmed the responsibility of cow milk. We discuss the mechanisms that relate chronic urticaria to delayed hypersensitivity.

Adult↗
PubMed1998

Enteroscopy.

Explore the source record for details and available documents.

Endoscopy, Gastrointestinal↗
PubMed1997

[Treatment and prevention of food allergy].

Treatment of food allergy is above all etiological, and needs suppression of the food on condition: that it has been proven to be responsible, that it is not indispensible to nutrition. The etiological treatment may be associated with drug treatment: the anaphylactic reaction can be treated with adrenalin and corticosteroids, then chronic food allergy may be prevented or treated by: Sodium cromoglycate (Nalcron, Intercron). Ketotifen (Zaditen). Second generation anti-H1 that has a stronger anti-allergic action (Cetrizine, Loratidine). Immunotherapy or really habituation to the food is possible in some casas, but progress by ingestion of the food may be extremely slow. Prevention includes: Food of the pregnant and nursing woman: the mother should have a varied diet without excessive consumption of any food. For atopic infants diversification of foods should be late. Information to parents is essential.

Acute Disease↗
PubMed1997

[Treatment and prevention of food allergy].

Treatment of food allergy is above all etiological, and needs suppression of the food on condition: that it has been proven to be responsible, that it is not indispensible to nutrition. The etiological treatment may be associated with drug treatment: the anaphylactic reaction can be treated with adrenalin and corticosteroids, then chronic food allergy may be prevented or treated by: Sodium cromoglycate (Nalcron, Intercron). Ketotifen (Zaditen). Second generation anti-H1 that has a stronger anti-allergic action (Cetrizine, Loratidine). Immunotherapy or really habituation to the food is possible in some cases, but progress by ingestion of the food may be extremely slow. Prevention includes: Food of the pregnant and nursing woman: the mother should have a varied diet without excessive consumption of any food. For atopic infants diversification of foods should be late. Information to parents is essential.

Anti-Allergic Agents↗
PubMed1996

A generalization of the mixture model in the mapping of quantitative trait loci for progeny from a biparental cross of inbred lines.

The recent advent of molecular markers has created a great potential for the understanding of quantitative inheritance. In parallel to rapid developments and improvements in molecular marker technologies, biometrical models have been constructed, refined and generalized for the mapping of quantitative trait loci (QTL). However, current models present restrictions in terms of breeding designs to which they apply. In this paper, we develop an approach for the generalization of the mixture model for progeny from a single bi-parental cross of inbred lines. Detailed derivations are given for genetic designs involving populations developed by selfing, i.e., where marker genotypes are obtained from Fx (x > or = 2) individuals and where phenotypes are measured on Fy (y > or = x) individuals or families. Extensions to designs involving doubled-haploids, backcross-derived individuals and random matings are outlined. The derivations presented here can easily be combined with current QTL mapping approaches.

Crosses, Genetic↗
PubMed1994

Pharmacokinetics of sparfloxacin in patients with renal impairment.

The pharmacokinetics of sparfloxacin were studied in 14 renal failure patients (group I, 7 with creatinine clearance of > 10 to 30 ml/min; and group II, 7 with creatinine clearance of < or = 10 ml/min) after a single oral dose of 400 mg. Plasma and urine samples were collected up to 144 h postdosing for determination of parent and total (parent-plus-glucuronide-conjugated) sparfloxacin levels, by high-pressure liquid chromatography assay and UV detection. The elimination of the drug in patients compared with that in healthy volunteers was markedly impaired. The mean elimination half-lives of sparfloxacin were 34.9 and 38.5 h in group I and group II, respectively, versus 19.1 h in healthy volunteers. Conjugated drug half-lives were 23.7, 35.0, and 15.3 h, respectively. The renal clearance of the drug was markedly reduced in the patients, with values of 6.8, 4.8, and 21.2 ml/min determined for group I, group II, and healthy subjects, respectively, for parent sparfloxacin and with values of 31.5, 14.0, and 327 ml/min for conjugated sparfloxacin. The nonrenal clearance of sparfloxacin was moderately, but not significantly, decreased in group II renal failure patients. No difference between the two groups of patients was detected in sparfloxacin levels in plasma. A significant relationship between pharmacokinetic parameters and creatinine clearance was observed only for renal clearance of parent or conjugated sparfloxacin.

Adult↗