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Biomedical subjects

D Auger

Publications and source records attributed to D Auger.

At least 19 recordsLinked to original sources
PubMed1998

Atherogenic, hemostatic, and other potential risk markers in subjects with previous isolated myocardial infarction compared with long-standing uncomplicated stable angina.

BACKGROUND: Several atherogenic, hemostatic, inflammatory, and genetic parameters and markers have been implicated as risk factors in coronary artery disease, although whether they are risk factors for acute as opposed to chronic coronary disease is unclear. METHODS AND RESULTS: Fifty subjects with an isolated myocardial infarction >3 months previously were compared with 50 subjects with a minimum 3-year history of stable angina, documented coronary artery disease, normal electrocardiogram and normal ventricular wall motion, and no episode suggesting infarction or unstable angina. Biologic variables analyzed included apolipoprotein B (apo B), lipoprotein (a), C-reactive protein (CRP), fibrinogen, factor VII, tissue plasminogen activator (TPA) and inhibitor (PAI-1), thrombin-antithrombin (TAT), fragment 1+2 (F1+2), von Willebrand factor (vWF), activated protein C resistance, homocyst(e)ine, anticardiolipin antibodies, blood group, and the angiotensin-converting enzyme insertion/deletion (I/D) and angiotensin II receptor gene polymorphisms. There were no significant differences between the 2 groups for any of the variables studied, although fibrinogen and F 1+2 tended to be slightly higher in the angina group (P = .09 for each). These significant correlations were present: age with fibrinogen, homocyst(e)ine, and vWF; factor VII with apo B, homocyst(e)ine, and TPA; apo B with TPA and CRP; CRP with fibrinogen, TPA, PAI-1, and factor VII; fibrinogen with vWF. CONCLUSIONS: Examination of atherogenic, hemostatic, inflammation, and genetic variables in the clinically quiescent state permitted no distinction between subjects with a previous isolated myocardial infarction in contrast to those with long-standing uncomplicated stable angina, favoring the notion that acute coronary events occur at random on a varying background of atherosclerosis. The multiple correlations found among these variables also underscore their complex interaction in the atherosclerotic process.

Adult↗
PubMed1998

Cytomegalovirus and human herpesvirus-6 trans-activate the HIV-1 long terminal repeat via multiple response regions in human fetal astrocytes.

Cytomegalovirus (CMV) and human herpesvirus-6 (HHV-6) infection stimulated HIV-1 replication and trans-activated the HIV-1 promoter (the long terminal repeat or LTR) to a similar extent in transfected, nonimmortalized, human fetal astrocytes. CMV infection increased basal LTR expression by approximately sevenfold, while HHV-6 infection increased basal LTR expression by fourfold. This enhancing effect required cell-cell contact between CMV-infected or HHV-6-infected and LTR-containing cells. To determine the target regions on the HIV promoter that respond to CMV and HHV-6 trans-activation, several modified LTR-reporter gene constructs were tested. Loss of functional NFkappaB, Sp1, or upstream modulatory sites on the LTR caused significant reduction ofbasal LTR expression in astrocytes. These elements also mediated the trans-activation events during HHV-6 or CMV infection in astrocytes, though to varying degrees. Electrophoretic mobility shift assays (EMSA) indicated that core, enhancer, and upstream modulatory regions of the LTR interacted specifically with nuclear proteins from both uninfected and CMV- or HHV-6-infected human fetal astrocytes. CMV or HHV-6 infection did not appear to induce unique, LTR-specific nuclear binding proteins, but rather enhanced the relative proportion of some of the existing protein complexes, in particular, the complexes formed with the AP-1 binding sites on the HIV-1 LTR (nt - 354 to - 316). Our data suggest that CMV or HHV-6 trans-activation of HIV LTR activity in human fetal astrocytes proceeds via intracellular molecular interactions involving herpesviral gene products, cellular proteins, and multiple sites on the LTR upstream of the TATA box. The pattern of LTR activity in astrocytes suggests that host cell factors modulating HIV expression may differ from those dominant in T-cells or immortalized astroglia, and this could contribute to differences in the astrocyte's ability to support HIV replication.

Astrocytes↗
PubMed1995

Automated optical scanning for rapid sizing of chewed food particles in masticatory tests.

Analysis of the reduction in sizes of particles after chewing has been a standard method for assessing masticatory efficiency for over 40 years, but the sizing of particles with sieves is very time consuming. A rapid simple method of measuring chewed almond particle sizes by an optical scanning method has been developed and is described. The aim of this study is to validate the accuracy, repeatability and speed of the application of an optical scanning system in measuring chewed particles. To determine the accuracy, paper circles were measured and compared with the travelling microscope measurements. The effect of orientation of the images were assessed by measuring three irregular shaped pieces of paper and three different sized pieces of chewed almonds. Measurements were taken singly at 18 degrees increments from 0-180 degrees orientations with each piece of paper. To assess the repeatability of measuring chewed particles, the particles from a single masticated almond washed with water and absolute alcohol were spread, separated and measured by the optical scanning system. The samples were then remeasured 10 times. The reproducibility of the method was investigated using three repeated masticatory tests for each subject in a group of 13 young dentate subjects. The speed of spreading the particles and of measurement was assessed. The absolute error range for a mean area of 31 mm2 was 2.85% to 7.32% with a mean of 3.86%. The relative accuracy of measurement was higher for larger particles but in no case was the standard deviation > 0.4 mm2.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1994

[Therapeutic management of superficial venous thrombosis with calcium nadroparin. Dosage testing and comparison with a non-steroidal anti-inflammatory agent].

This multicentre, randomised, open trial compared the efficacy and safety/acceptability of calcium nadroparin, a non-steroidal anti-inflammatory drug, naproxen, in the treatment of superficial venous thrombosis of the lower limbs, in 117 patients. Calcium nadroparin was given at two dosage regimens: a fixed dose (daily subcutaneous injection of 0.6 ml, i.e. 6150 anti-Xa IU, n = 38) or a dose adjusted for body weight (31.5 anti-Xa IU/kg, n = 40). The naproxen was given orally (500 mg as a single daily dose, n = 39). Treatment duration was 6 days in both groups. A very marked difference was found to the advantage of calcium nadroparin, although this difference did not reach the threshold of statistical significance with regard to repermeabilisation of the thrombosed superficial vein at the end of treatment. The most striking result concerned the regression of symptoms and signs. At the end of treatment (D7), there was a significant difference to the advantage of the calcium nadroparin groups, particularly regarding feelings of heat and redness (p < 0.001 in both cases). The persistence of symptoms and signs at 8 weeks was statistically less frequent (p = 0.007) in the calcium nadroparin groups than in the naproxen group. Efficacy did not differ between the calcium nadroparin fixed dose and calcium nadroparin weight-adjusted dose groups. No adverse events nor clinically significant laboratory abnormalities were encountered. Antithrombotic treatment of superficial venous thromboses with calcium nadroparin is well tolerated and appears to be associated with a greater improvement in symptoms and signs, in the short and mid-terms, than that obtained with an oral non-steroidal anti-inflammatory.

Adult↗
PubMed1993

Phosphoglucomutase in Saccharomyces cerevisiae is a cytoplasmic glycoprotein and the acceptor for a Glc-phosphotransferase.

UDP-glucose:glycoprotein glucose-1-phosphotransferase (Glc-phosphotransferase) catalyzes the transfer of Glc-1-P from UDP-Glc to mannose residues on acceptor glycoproteins. The predominant acceptor in vertebrates and Paramecium tetraurelia is a cytoplasmic 62-kDa glycoprotein. To determine if the yeast Saccharomyces cerevisiae also possesses Glc-phosphotransferase activity, a crude cellular lysate was incubated with [beta-32P]UDP-Glc and analyzed. A phosphoglycoprotein having an apparent molecular mass of 62 kDa (pgp62) was found to be the predominant labeled macromolecule. Reconstitution experiments determined that both a soluble and membrane fraction were required for labeling, and suggested that the Glc-phosphotransferase is membrane-associated while pgp62 is cytoplasmic. The reaction is evolutionarily conserved to the extent that rat liver Glc-phosphotransferase was capable of recognizing the yeast acceptor and vice versa. The yeast 62-kDa acceptor was purified, and partial amino acid sequences showed a high level of identity with rabbit muscle phosphoglucomutase. Subsequently, both yeast and rabbit muscle phosphoglucomutase were found to be acceptors in the Glc-phosphotransferase reaction. The label was found on a tryptic peptide distinct from that containing the enzyme's active site serine. When phosphoglucomutase was overexpressed, an increase was seen in Glc-phosphotransferase acceptor activity and in specific metabolic labeling of the acceptor by glucose and mannose.

Amino Acid Sequence↗
PubMed1992

Identification of a processed pseudogene related to the functional gene encoding the GM2 activator protein: localization of the pseudogene to human chromosome 3 and the functional gene to human chromosome 5.

The GM2 activator protein is an essential substrate cofactor for the hydrolysis of GM2 ganglioside by lysosomal beta-hexosaminidase A (EC 3.2.1.52). There have been conflicting reports as to the chromosomal localization of the gene encoding the activator. We demonstrate here that these conflicts were caused by the presence of a previously unidentified processed activator-pseudogene on chromosome 3, and we confirm a previous ELISA-based localization of the functional activator gene to chromosome 5. Our data indicate that the functional activator locus can still be considered a candidate site for defects causing some forms of spinal muscular atrophy.

Animals↗
PubMed1990

GDA-J/F3 monoclonal antibody as a novel probe for the human sperm tail fibrous sheath and its anomalies.

GDA-J/F3 monoclonal antibody (MoAb) recognized an antigen in the fibrous sheath (FS) of human spermatozoa. This was based on: (i) intracellular localization of the antigen which was limited to the principal piece of the sperm tail; (ii) its absence from the cilia of trachea and nasal mucosa which lack FS; (iii) immunogold electron microscopy (IEM) which confirmed its ultrastructural localization to the FS. The antibody was used for the detection of abnormal germ cells in human semen. Nucleated cells other than spermatozoa (NCOS) obtained from oligozoospermic donors were screened with GDA-J/F3 MoAb using the indirect immunofluorescence test. The antibody which stains only the tails in normal cells, produced diffuse cytoplasmic immunofluorescence inside some spermatids. Using phase contrast microscopy, the tails in these spermatids were either present or undetectable. Electron microscopy studies of the NCOS showed the lack of the FS in those which had the tails (afibrous tail), or the presence of disorganized tails (tail dysgenesis) in the others. This antibody therefore provides a useful analytical tool for probing the FS as well as for the easy identification of certain abnormal germ cells in human semen.

Antibodies, Monoclonal↗
PubMed1989

Effect of parathyroid hormone on PO4 transport through the human placenta microvilli.

The transport of phosphate (PO4) through the placenta is a secondary active phenomenon whose control mechanisms are unknown. In this study, we investigated whether PTH, the main hormone regulating PO4 transport in the kidney and gut, has a similar role in the placenta. Incubation of normal term human placenta fragments for 1 min with PTH increased the cAMP content of the tissue by 285%. A dose-response curve of the effect of the hormone showed that the cAMP accumulation reached a maximal level with 3.5 x 10(-8) M PTH. Incubation of the placenta fragments with 10(-4) M di-butyryl cAMP resulted in a significant decrease in the PO4 uptake by the brush border membranes prepared from these fragments. Increasing concentrations of di-butyryl cAMP from 0 to 10(-3) M significantly decreased the PO4 uptake from 0.29 +/- 0.02 to 0.22 +/- 0.01 pmol/micrograms/20 s. Similarly, incubation of the placental tissue with PTH resulted in a comparable decrease in the PO4 uptake by the corresponding brush border membrane vesicles. In contrast, direct incubation of brush border membranes with the hormone did not influence PO4 uptake. It is concluded that PTH probably regulates the PO4 transport through the placenta syncytio-trophoblast cell through cAMP mediation. Because adenylate cyclase is located in the basal plasma membrane, it is likely that only the fetal hormone is implicated in this process.

Biological Transport, Active↗
PubMed1988

Parathyroid hormone receptor in human placental syncytiotrophoblast brush border and basal plasma membranes.

The syncytiotrophoblast of the placenta is the site of exchange of nutrients and minerals between the mother and fetus. We have recently demonstrated that PTH influences, in vitro, phosphate transport through the placenta brush border membranes (BBM) and increases cAMP accumulation in placental tissue. To demonstrate the site of binding of PTH in the cytoplasmic membrane, we have purified two polar membranes: the first located on the apical side, the BBM, and the second, on the fetal side, the basal plasma membrane (BPM). BBM were enriched 24-fold in alkaline phosphatase (marker for BBM), and the BPM was enriched 37-fold in binding of [3H] dihydroalprenolol (marker for BPM) compared to homogenate. Both placental membranes contain binding sites (maximum binding = 0.550 +/- 0.032 and 0.298 +/- 0.065 pmol/mg protein for BBM and BPM, respectively) with similar affinities (Kd = 2.05 +/- 0.23 and 1.78 +/- 0.19 nM, respectively) for 125I-[Nle8,Nle18,Tyr34] bovine (b) PTH-(1-34) amide. The three bovine preparations [bPTH-(1-34), its analog [Nle8,Nle18,Try34]bPTH-(1-34) amide, and the antagonist bPTH-(3-34)] were equipotent in binding to both placental membranes. In contrast, human PTH-(1-84) was more effective in displacing the bovine radioligand in BBM. Thyrocalcitonin and insulin, two non-PTH peptides, did not significantly displace the radioligand in BBM and BPM. Adenylate cyclase activity, located exclusively in BPM, was stimulated by PTH. Since the enzyme is absent from BBM, it is probable that the binding of the hormone to this membrane activates another system of messengers.

Adenylyl Cyclases↗
PubMed1986

Synthesis and processing of the envelope gp55-116 complex of human cytomegalovirus.

The envelope of human cytomegalovirus has been reported to contain between three and eight glycoproteins. Major constituents of the envelope include two abundant glycoproteins with estimated molecular weights of 55,000 (gp55) and 116,000 (gp116). These two glycoproteins have been shown to exist as a disulfide-linked complex (gp55-116) within the envelope of mature virions. Utilizing a panel of monoclonal antibodies reactive with the gp55-116 complex, we characterized the synthesis and processing of these two virion proteins. Infected cells were shown to contain two glycosylated proteins of 160,000 and 150,000 daltons as well as the mature gp55 and gp116. Pulse-chase analysis indicated that gp150 was a precursor protein of gp160. The mature gp55 and gp116 were generated, in turn, by cleavage of gp160. Antigenic and structural analysis revealed that gp55 and gp116 shared little structural homology and no detectable antigenic cross-reactivity. The results of this study are discussed in relation to the synthesis of envelope proteins of other herpesviruses.

Antibodies, Monoclonal↗
PubMed1986

Human cytomegalovirus virion-associated protein with kinase activity.

Protein kinase activity was detected in immunoprecipitates of human cytomegalovirus virions and infected cells by using a monoclonal antibody directed against an abundant 68,000-dalton virion structural protein. Purification of this protein by electrophoresis confirmed that the kinase activity was associated with this protein. The kinase activity was dependent on divalent cations (Mg2+, Mn2+) and cyclic nucleotide independent and exhibited optimal activity at pH 7 to 8. The kinase phosphorylated threonine and serine but not tyrosine.

Antibodies, Viral↗
PubMed1985

Identification of a 65 000 dalton virion envelope protein of human cytomegalovirus.

Human cytomegalovirus (CMV) specific monoclonal antibodies were shown to react with a broadly migrating 65-52 kDa virion envelope protein. These antibodies efficiently neutralized CMV in vitro (greater than 98% plaque reduction), suggesting that this envelope protein was an important target of neutralizing antibodies. This virion envelope protein was shown to be antigenically and electrophoretically distinct from a more abundant 68 kDa virion protein. The relationship between these virion proteins is discussed.

Antibodies, Monoclonal↗