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P Ordronneau

Publications and source records attributed to P Ordronneau.

10 recordsLinked to original sources
PubMed2001

Glycine antagonist in neuroprotection for patients with acute stroke: GAIN Americas: a randomized controlled trial.

CONTEXT: Elucidation of the ischemic cascade has helped stimulate development of neuroprotective drugs aimed at limiting brain injury in the hours following an ischemic stroke. To date, none of these drugs has shown clinical efficacy. OBJECTIVE: To examine the efficacy of gavestinel (GV150526), an antagonist of the glycine site of the N-methyl-D-aspartate receptor, as a neuroprotective therapy for acute ischemic stroke when administered within 6 hours of symptom onset. DESIGN: The Glycine Antagonist in Neuroprotection (GAIN) Americas trial, a randomized, double-blind placebo-controlled trial with enrollment from April 1998 to October 1999. SETTING: One hundred thirty-two hospital centers across the United States and Canada. PATIENTS: The primary efficacy population consisted of 1367 ischemic stroke patients with a predefined level of limb weakness and functional independence prior to stroke, stratified at randomization by age (</=75 vs >75 years) and initial stroke severity (National Institutes of Health [NIH] Stroke Scale scores of 2-5, 6-13, or >/=14). INTERVENTION: Patients were randomly assigned to receive an intravenous loading dose (800 mg) plus 5 maintenance doses (200 mg every 12 hours) of gavestinel (n = 701) or placebo (n = 666) for 3 days. MAIN OUTCOME MEASURE: Functional capability at 3 months, measured by the Barthel Index (BI), with scores trichotomized as dead/0-55, 60-90, and 95-100, compared between the gavestinel and placebo groups. RESULTS: Treatment groups were well matched for baseline characteristics. For each group, median NIH Stroke Scale was 12, median age was 72 years, and median time to treatment was 5.2 hours. No statistically significant improvement on the 3-month BI trichotomy was demonstrated for gavestinel (P =.79). The proportion who were functionally independent (BI score = 95-100) was 39% in the gavestinel group and 37% in the placebo group. No statistically significant difference in 3-month survival was observed using Kaplan-Meier curves (P =.11). No other secondary end point suggested an advantage for gavestinel. Among the 333 patients (24%) who received recombinant tissue-type plasminogen activator, there was also no benefit for gavestinel (P =.53). There were no serious safety issues. CONCLUSION: In this study, gavestinel administered up to 6 hours after an acute ischemic stroke did not improve functional outcome at 3 months.

Aged↗
PubMed1996

Distribution of immunoreactive androgen-binding protein/sex hormone-binding globulin in tissues of the fetal rat.

Androgen-binding protein/sex hormone-binding globulin (ABP/SHBG) is an extracellular carrier protein that binds androgens and estrogens with high affinity. In the adult, ABP/SHBG is thought to function in the male reproductive system and the general circulation in both sexes to modulate the actions of sex steroids. The ABP/SHBG gene is also expressed in the embryonic rat liver, where SHBG is secreted into the fetal blood of male and female rats. The embryo also expresses an alternative SHBG with a unique N-terminal sequence. In this study, the distribution of immunoreactive SHBG in the 17-day-old male fetal rat was determined with six antisera. In general, all of the antisera reacted with the same structures. Specific tissue immunoreactivity was mostly cytoplasmic and/or extracellular. By far the most prominent immunoreactive structures were the mesoderm-derived tissues: connective tissue, striated and cardiac muscle, cartilage, and the liver hematopoietic system. In addition, all regions of the fetal brain contained immunoreactive neurons. In the developing male reproductive system, there was minor reactivity in the testicular cords, whereas the connective tissue in the differentiating Wolffian duct stained with all of the antisera. The Wolffian duct epithelium and epithelia in other developing organs contained small amounts of immunoreactive SHBG, except for the lung, which stained in the epithelial extracellular matrix. An antibody raised against a unique N-terminal peptide specific for the alternative SHBG protein revealed that it was also present in many tissues. These data suggest that SHBG is important for the differentiation of mesodermal tissues. SHBG may modulate the action of androgens in embryonic stroma, thereby regulating development of the epithelium in hormone-dependent tissues.

Amino Acid Sequence↗
PubMed1992

Molecular requirements for hapten binding to antibodies against glutamate and aspartate.

Molecular requirements for hapten recognition by antibodies raised in rabbits against glutaraldehyde conjugates of L-glutamate and L-aspartate were determined in enzyme immunoassays by measuring the displacement of binding of glutamate and aspartate, respectively, by a large number of selected haptens to two anti-glutamate and two anti-aspartate sera. The results indicate that N-terminal modifications of the amino acids, such as the presence of an N-acetyl or N-carbamyl group or the addition of a second amino acid to form dipeptides with C-terminal glutamate or aspartate, are tolerated to variable degrees, more so by the aspartate than the glutamate antisera. The antibodies possess point-to-point recognition sites for the two carboxyl groups present in both amino acids. Strong shape complementarity between the amino acids and their respective binding sites is suggested by the lack of recognition of the appropriate D stereoisomers by any of the antibodies. Changes in the distance between the two carboxyl groups, or modification, replacement or loss of either or both carboxyl groups, strongly reduce or eliminate binding. Based on these results, we suggest that other antibodies raised to similar conjugates of these amino acids are likely to share similar recognition characteristics. In addition, the results provide a rational background for the evaluation of antibody specificity and the interpretation of results in immunocytochemical studies using antisera to glutamate and aspartate.

Amino Acid Sequence↗
PubMed1991

An efficient enzyme immunoassay for glutamate using glutaraldehyde coupling of the hapten to microtiter plates.

In order to coat microtiter plates for enzyme immunoassays (EIAs), amino acids and other haptens are usually coupled to larger protein molecules. The formation of such conjugates is not always reproducible. This may lead to inconsistent hapten-protein stoichiometries, unfavorable orientation of the hapten on the protein and/or well-to-well variation in the concentration of the available hapten. In the assay described here the excitatory amino acid (EAA) Glu is coupled directly to polystyrene microtiter wells with GA. Each step of the assay was tested for maximum efficiency. The resulting EIA with Glu as a competitor gave excellent reproducibility (coefficient of variation = 5.87%), an EC50 of 2.02 X 10(-5) M and a detection limit of 1.26 X 10(-6) M. This EIA method is generally useful for a variety of antisera to amino acids and small peptides and a wide range of competing substances. It can be used to characterize the conformational requirements for antigen binding, to assay for glutamate or to identify compounds with glutamate-like structure in unknown solutions.

Alanine↗
PubMed1989

Developmental expression of an androgen-regulated epididymal protein.

Acidic epididymal glycoprotein (AEG), an androgen-regulated secretory protein of rat epididymis, was quantitated by RIA in epididymal extracts of rats of increasing age. Although detectable at 1 day of age, significant concentrations of AEG were not measured until 20 days; concentrations increased steadily, so that by 120 days of age, AEG represented 10% of total soluble protein. AEG mRNA was detected by Northern blot analysis of RNA from epididymides of 5-day-old animals and rapidly increased in amount between 20 and 35 days, reaching a maximum at 45 days. Using immunohistochemistry, AEG was localized in epididymal epithelial cells at 1 day of age. The number of cells staining for AEG increased markedly after 15 days. At 120 days, the immunoreactivity was predominantly localized to the lumen of the epithelial duct. To delineate factors that may influence AEG expression in the developing epididymis, we measured concentrations of androgen and androgen receptor mRNA in tissue extracts prepared from animals of various ages. Androgen receptor mRNA was detectable in epididymal extracts isolated from 1- to 90-day-old animals. Epididymal androgen concentrations were high at all ages (range, 6.0-31.2 ng/g tissue). The marked increase in AEG mRNA concentration at 20 days of age was not associated with an increase in either androgen or androgen receptor mRNA concentrations, suggesting that other factors may be necessary for AEG expression.

Aging↗
PubMed1984

Corticotropin-releasing factor (CRF)-like immunoreactivity in the gastro-entero-pancreatic endocrine system.

CRF has been detected in the endocrine pancreas by immunocytochemistry with an antiserum that recognizes mainly the C-terminal portion of CRF-41. CRF-containing cells have been shown to be present in the pancreas of representative species of fishes, amphibians, reptiles, birds, and mammals including man. Light and electron microscopic observations indicate that the CRF-containing cells in the endocrine pancreas are similar to glucagon (A) cells both in their morphology and distribution. Individual CRF-containing cells are also found scattered in the exocrine pancreas in all species studied. In addition, CRF-containing cells have been identified in the human, monkey, cat, and rat stomach and small intestine. Recent reports also indicate that CRF-like immunoreactivity is present in the circulating blood, the adrenal medulla, and the placenta. Finally, several peripheral (pancreas, stomach, colon, lung and thyroid) tumors which produced corticotropin-releasing substances have been described by others. Although the peripheral actions of CRF are not yet known, these observations indicate that it is widely distributed in peripheral tissues and it may also represent a new tumor marker.

Animals↗
PubMed1981

Four unlabeled antibody bridge techniques: a comparison.

Four unlabeled antibody immunocytochemical techniques, the "single bridge" (Avrameas S: Immunocytochemistry 6:825, 1969; Mason TE, Phifer RF, Spicer SS, Swallow RS, Dreskin RD: J Histochem Cytochem 17:190, 1969a; Sternberger LA, Cuculis JJ: 1969), the "single peroxidase-antiperoxidase (PAP)" (Sternberger LA, Hardy PH Jr, Cuculis JJ, Meyer HG: J Histochem Cytochem 18:315, 1970), the "double PAP" (Vacca LL, Rosario SL, Zimmerman EA, Tomashefsky P, Ng P-Y, Hsu KC: J Histochem Cytochem 23:208, 1975) and the "double bridge" (Ordronneau P, Petrusz P: Am J Anat 158:491, 1980) were compared at both the light and electron microscopic levels. The "double" procedures involved repeating incubations with the bridge antibody, in this case, sheep anti-rabbit gamma globulin, followed either by a second PAP step for the "double PAP" or a second anti-horseradish peroxidase step and a single incubation in horseradish peroxidase for the "double bridge." At both the light and electron microscopic levels the staining intensity was greater with the "double" techniques than with the "single" ones. This is probably due to amplification achieved with the second sheep anti-rabbit gamma globulin step, permitting an increase in the number of horseradish peroxidase molecules bound for each molecule of tissue-bound primary antibody. Also, the quality of the various commercial PAP preparations tested was variable. With the weaker ones the staining intensity could be increased by performing an incubation in fresh horseradish peroxidase after the PAP step. Finally, in electron microscopic studies, the reaction products formed in both the bridge and PAP procedures were identical in shape and size.

Animals↗
PubMed1980

Immunocytochemical demonstration of anterior pituitary hormones in the pars tuberalis of long-term hypophysectomized rats.

The hormone-containing cells of the pars tuberalis of the rat adenohypophysis were studied, 4--5 months after hypophysectomy, with a double bridge immunocytochemical technique and with antisera directed against the hormones of the pars distalis. Corticotropes, lactotropes, somatotropes, thyrotropes, and gonadotropes were found in the pars tuberalis of all animals. These cells are well well situated to receive blood, nerve terminals, and tanycyte processes from the median eminence and, thus, to be influenced by the chemical messengers from the hypothalamus. It is concluded that the pars tuberalis has to be regarded as a potential source of adenohypophyseal hormones in an animal model traditionally considered to be free of such hormones.

Adrenocorticotropic Hormone↗
PubMed1980

Criteria of reliability for light microscopic immunocytochemical staining.

The following criteria of reliability are defined and discussed for immunocytochemical staining at the light microscopical level: efficiency, accuracy, precision, sensitivity, and specificity. Whenever practical, tests are suggested for obtaining information on the extent to which these criteria are fulfilled in a given system, and procedures are outlined for improving immunocytochemical staining in terms of these criteria. It is suggested that consideration of reliability criteria will help investigators in their choice of methodology, design of experimental strategy, and valid interpretation of the results.

Animals↗