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Biomedical subjects

G Gay

Publications and source records attributed to G Gay.

At least 37 records · Page 2Linked to original sources
PubMed2004

The role of video capsule endoscopy in the diagnosis of digestive diseases: a review of current possibilities.

Video capsule endoscopy represents a significant advance in the investigation of intestinal diseases. The performance of the procedure and indications are reviewed here in order to establish guidelines for its use, in accordance with current knowledge from the published literature. Capsule endoscopy is performed in patients who have fasted for 12 h, but who are allowed to drink 2 h after and to eat 4 h after ingesting the capsule. Software features highlighting suspected blood and allowing simultaneous viewing of two images reduce the time required to review the findings, as well as improving the diagnostic yield. Pacemakers and other electrical medical devices are no longer a contraindication to the procedure. Indications that have been validated include obscure digestive bleeding, intestinal lesions related to nonsteroidal anti-inflammatory drugs, and familial polyposis. Capsule endoscopy frequently detects intestinal lesions in patients with Crohn's disease and could become the first-choice examination in patients with suspected Crohn's disease after conventional endoscopic investigations. Other indications currently under evaluation include celiac disease, pediatric indications, and examination of other parts of the gastrointestinal tract.

Contraindications↗
PubMed2004

Clinical usefulness of the endoscopic video capsule as the initial intestinal investigation in patients with obscure digestive bleeding: validation of a diagnostic strategy based on the patient outcome after 12 months.

BACKGROUND AND STUDY AIMS: In patients with obscure digestive bleeding, the bleeding source is frequently located in the small bowel. Capsule endoscopy (CE) is an effective method of investigating the whole small bowel in such patients. In the present study, a diagnostic approach was tested in patients with obscure digestive bleeding in which CE was included as the initial examination of the small bowel when the esophagogastroduodenoscopy (EGD) and colonoscopy findings were normal. PATIENTS AND METHODS: Patients admitted between October 2000 and February 2002 for obscure digestive bleeding underwent CE as the initial intestinal investigation, and the further management was decided on the basis of the results. After 12 months, follow-up data were obtained from all patients and referring physicians. The positive predictive value was calculated as the percentage of patients in whom CE detected a relevant lesion, and the negative predictive value as the percentage of patients with normal CE in whom no intestinal lesion was detected during the follow-up period. RESULTS: Forty-four patients (21 men, 23 women, aged 63 +/- 17 y) were included in the study. Twenty-two had overt bleeding and 22 had occult bleeding. CE detected an intestinal lesion in 18 patients (41.9 %)-- nine with angiomas, five with ulcers, one with a tumor, two with portal hypertension, and one with ischemic ileitis. The findings were normal in 17 patients (39.5 %). CE detected upper gastrointestinal lesions missed at EGD in four patients and blood in the stomach in two patients or in the proximal colon in three, leading to new endoscopies. Intestinal lesions detected at CE were treated as follows: push enteroscopy with treatment in eight patients, surgery in four, and medical treatment in six. In eight patients who underwent push enteroscopy, the procedure did not reveal lesions missed by CE. After 1 year, 15 of the 18 patients treated for intestinal lesions had no further bleeding and no anemia; one died after surgery (for resection of an ischemic intestinal loop), one relapsed, and one was diagnosed with a different intestinal condition. In all patients with extraintestinal lesions or blood detected at CE, further endoscopies led to diagnosis and therapy, with a favorable outcome. In patients with normal CE, no intestinal lesion was detected, but an extraintestinal source of bleeding was diagnosed and treated in nine patients (in the upper gastrointestinal tract in five cases and in the colon in four). Three patients had anemia of hematological origin and four had inadequate iron intake. The positive predictive value of CE was 94.4 % in patients with intestinal lesions, and the negative predictive value was 100 % in patients with normal CE findings. CONCLUSIONS: In patients with obscure digestive bleeding, CE positively predicted the intestinal diagnosis or normal status in 95.5 % of cases. A diagnostic approach to obscure digestive bleeding that includes CE after the initial endoscopic work-up thus appears to be a valid strategy for small-bowel examinations.

Adult↗
PubMed2003

Diagnostic value of endoscopic capsule in patients with obscure digestive bleeding: blinded comparison with video push-enteroscopy.

BACKGROUND AND STUDY AIMS: This study was designed to prospectively compare the diagnostic yield of the M2A endoscopic capsule with that of video push-enteroscopy in exploring the small intestine in patients with obscure digestive bleeding. PATIENTS AND METHODS: Patients with either occult or overt obscure digestive bleeding and a negative endoscopic work-up underwent a double intestinal investigation, with video push-enteroscopy and a wireless capsule, performed blindly by separate examiners. The diagnostic yield for each technique was defined as the frequency of detection of clinically relevant intestinal lesions, i. e. those having the potential for bleeding. RESULTS: 60 patients (27 men, 33 women; age 58 +/- 18 years; hemoglobin 9.4 +/- 2.5 g/dl) were included, 32 with occult and 28 with overt bleeding. Results were analyzed for 58 patients, who completed both examinations. Lesions were detected in 43 patients: with both techniques in 19, only by capsule in 21, and, conversely, only by push-enteroscopy in 3 ( P = 0.04). Final diagnoses were as follows: a P2 lesion with high bleeding potential in 28 patients (19 angiomata, 6 ulcerations, 2 tumors, 1 case of intestinal varices); a P1 lesion with intermediate bleeding potential in 15 patients (2 patients with mucosal erosions, 13 patients with mucosal red spots); and there were normal findings from 15 procedures. No procedure induced any complication. CONCLUSION: The use of the wireless endoscopy capsule detects significantly more clinically relevant intestinal lesions than video push-enteroscopy in patients with obscure digestive bleeding, raising the diagnostic yield to 67.2 %. Its influence on the clinical outcome for patients needs further investigation.

Adult↗
PubMed2002

Structural organization of the group-1 chromosomes of two bread wheat sister lines.

Eureka and Renan are two French bread wheat cultivars derived from a 4-way cross. Using molecular markers (essentially RFLPs), we studied the structure of the group-1 chromosomes of these two genotypes, their parents and a doubled-haploid (DH) population derived from their F(1). Using the DH population (102 lines), a molecular map of the three homoeologous group-1 chromosomes was produced and compared with the map established on another intervarietal cross: Courtot x Chinese Spring (Cadalen et al. 1997). The polymorphic markers were mapped on the DH population and characterized on the four grand-parents, allowing us to compare the structural organization of the group-1 chromosomes of Eureka and Renan and determine their origin. These chromosomes were very different, except for small regions (1AL proximal and 1BL distal) which were identical.

Biological Evolution↗
PubMed2002

Study of the relationship between pre-harvest sprouting and grain color by quantitative trait loci analysis in a whitexred grain bread-wheat cross.

In many wheat ( Triticum aestivumL.) growing areas, pre-harvest sprouting (PHS) may cause important damage, and in particular, it has deleterious effects on bread-making quality. The relationship between PHS and grain color is well known and could be due either to the pleiotropic effect of genes controlling red-testa pigmentation ( R) or to linkage between these genes and other genes affecting PHS. In the present work, we have studied a population of 194 recombinant inbred lines from the cross between two cultivars, 'Renan' and 'Récital', in order to detect QTLs for both PHS resistance and grain color. The variety 'Renan' has red kernels and is resistant to PHS, while 'Récital' has white grain and is highly susceptible to PHS. A molecular-marker linkage map of this cross was constructed using SSRs, RFLPs and AFLPs. The population was evaluated over 2 years at Clermont-Ferrand (France). PHS was evaluated on mature spikes under controlled conditions and red-grain color was measured using a chromameter. Over the 2 years, we detected four QTLs for PHS, all of them being co-localized with QTLs for grain color. Three of them were located on the long arm of chromosomes 3 A, 3B and 3D, close to the loci where the genes R and taVp1 were previously mapped. For these three QTLs, the resistance to PHS is due to the allele of the variety 'Renan'. Another co-located QTL for PHS and grain color was detected on the short arm of chromosome 5 A. The resistance for PHS for this QTL is due to the allele of 'Récital'.

Journal Article↗
PubMed2002

Characterization of a Pinus pinaster cDNA encoding an auxin up-regulated putative peroxidase in roots.

As part of a study to identify host plant genes regulated by fungal auxin during ectomycorrhiza formation, we differentially screened a cDNA library constructed from roots of auxin-treated Pinus pinaster (Ait.) Sol. seedlings. We identified three cDNAs up-regulated by auxin. Sequence analysis of one of these cDNAs, PpPrx75, revealed the presence of an open reading frame of 216 amino acids with the characteristic consensus sequences of plant peroxidases. The deduced amino acid sequence showed homology with Arabidopsis thaliana (L.) Heynh., Arachis hypogaea L. and Stylosanthes humilis HBK cationic peroxidases. Amino acid sequence identities in the conserved domains of plant peroxidases ranged from 60 to 100%. In PpPrx75, there are five cysteine residues and one histidine residue that are found at conserved positions among other peroxidases. A potential glycosylation site (NTS) is present in the deduced sequence. Phylogenetic analysis showed that PpPrx75 is closely related to two A. thaliana peroxidases. The PpPrx75 cDNA was induced by active auxins, ethylene, abscisic acid and quercetin, a flavonoid possibly involved in plant-microorganism interactions. Transcript accumulation was detected within 3 h following root induction by auxin, and the amount of mRNA increased over the following 24 h. The protein synthesis inhibitor cycloheximide did not inhibit indole-3-acetic acid-induced transcript accumulation, suggesting that PpPrx75 induction is a primary (direct) response to auxin. This cDNA can be used to study expression of an auxin-regulated peroxidase during ectomycorrhiza formation.

Amino Acid Sequence↗
PubMed2002

Hydrophobins in ectomycorrhizas: heterologous transcription of the Pisolithus HydPt-1 gene in yeast and Hebeloma cylindrosporum.

Hydrophobins are fungal cell wall proteins involved in aggregation of hyphae. Upon the development of the ectomycorrhizal symbiosis between tree roots and fungal hyphae, the transcripts of hydrophobin genes markedly accumulated. As the precise role of these proteins in symbiosis is not yet known, we develop heterologous expression system of the Pisolithus hydrophobin HYDPt-1. This gene has been introduced in Saccharomyces cerevisiae and in the ectomycorrhizal basidiomycete Hebeloma cylindrosporum. Introns were required for hydPt-1 transcript accumulation in the basidiomycete H. cylindrosporum. Heterologous transcript accumulation did not alter the phenotype of either species. The lack of altered phenotype resulted from the absence of HYDPt-1 polypeptide accumulation in transformed strains.

Basidiomycota↗
PubMed2002

[Delayed hypersensitivity to heparins and heparinoids].

Delayed hypersensitivity to heparins and heparinoïd is a problem for prophylaxis of thrombo embolic diseases. The hirudins did not seem to have any cross-reactivity with the two others groups of anticoagulants. We present two clinical cases of delayed type reactions to heparins and heparinoïd and we reviewed the literature about adverse reactions to low molecular weight heparins and the alternative possibilities.

Aged↗
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↗
PubMed2000

Pulmonary Mycobacterium bovis infection in a dog.

AIM: To describe the clinical course of a dog infected with Mycobacterium bovis causing a granulomatous pneumonia. CLINICAL FINDINGS: The dog initially presented with a persistent cough, inappetence and weight loss. Clinical findings included a fever, dyspnoea and tachypnoea, with haematological evidence of a mild neutrophilia and hypoalbuminaemia. Radiographs of the chest demonstrated a concomitant pneumothorax, pleural effusion, and a consolidated area within the left caudal lung lobe. An exploratory thoracotomy revealed this to be a ruptured granulomatous lesion. Subsequent histopathological, microbiological and genetic studies identified M. bovis as the causal agent. CLINICAL SIGNIFICANCE: Mycobacterium bovis infections should be included in the differential diagnosis of pulmonary disease and pleural effusions in dogs living in regions of New Zealand known to have a high incidence of mycobacterial infection in wildlife and farm animals.

Journal Article↗
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↗