Multicenter evaluation of the performance and clinical utility in longitudinal monitoring of the Bayer Immuno 1 complexed PSA assay.

We conducted a multicenter evaluation of the analytical and clinical performance of the automated Bayer Immuno 1 complexed PSA (cPSA) assay, and compared assay performance to the Bayer Immuno 1 PSA assay. We sought to determine whether measurements of cPSA could be of clinical utility in the management of patients with prostate cancer. Results of the 10-day imprecision across three evaluation sites produced total CV < 2.50% and an analytical sensitivity of 0.02 microgram/L. There was an increased trend in clinical sensitivity for prostate cancer with increasing stage of disease (71-86%). Clinical specificity for patients with benign urogenital disease was 74.8%, and for other nonprostate diseases ranged from 91.1-100%. Retrospective serial monitoring of 155 patients with prostate cancer demonstrated concordance of cPSA measurements to clinical status for 97% of the patients analyzed. Results from the clinical studies using the Bayer Immuno 1 cPSA assay were comparable to results obtained with the Bayer Immuno 1 PSA assay. The Bayer Immuno 1 cPSA assay demonstrates analytical performance and clinical effectiveness in the management of prostate cancer patients during the course of disease and therapy.     

Inequalities in women's health: looking at mortality differentials using an alternative approach

Data obtained from follow up of the 1971 census sample in the Office of Population Censuses and Surveys longitudinal study of England and Wales were used to look at women''s mortality differentials at ages 15-59. Women were grouped by combining information on marital state, own occupation, husband''s occupation (if married), economic activity, and indicators of household wealth (housing tenure and access to a car). Large groups were found with considerable differences in mortality. High mortality was associated with working in manual occupations and living in rented housing with no car in the household. In contrast, low mortality was associated with non-manual occupations and living in owner occupied housing with a car. Among married housewives and single women these extreme groups contributed 44% of expected deaths, the disadvantaged group experiencing death rates two and a half times that of the advantaged group. Smaller differences were found among married women with an occupational class.These findings are further evidence of the “health divide” in England and Wales and show that accurately to reflect the relation between a woman''s life circumstances and mortality it is necessary to utilise other measures than those based solely on occupation.     

Rat hepatocyte primary cultures

Summary Primary cultures of rat hepatocytes survived well for up to 4 days in defined medium in the presence of dexamethasone but not in its absence. The loss of viability was accompanied by a loss of ultrastructural features characteristic of hepatocytes. The cultures began producing plasminogen activator and a neutral protease after 24 hr in culture. Dexamethasone inhibited the production of both of these substances. The deterioration of the cultures appeared not to be related to plasminogen activator, but prolongation of survival by a variety of protease inhibitors suggested that the neutral protease might contribute to deterioration. Dr. Goldblatt was supported by Grant No. SG-87 from the American Cancer Society as an American Cancer Society Scholar while on sabbatical leave from the Department of Pathology, University of Connecticut Health Center, Farmington, Connecticut. This study was supported by Contracts NO1-CP-55705 from the National Cancer Institute and 68-02-2483 from the Environmental Protection Agency.     

Peroxidases in Relation to Removal of Dormancy and Germination of Apple Embryos

The changes in germination, peroxidase activity and isoperoxidase spectrum have been studied in apple embryos at 5°C (stratification) and at 20°C in the presence or absence of seed coats. The embryo dormancy is progressively released at 5°C, but not at 20°C. The peroxidase activity in embryos covered with seed coats is very low at 5°C as well as at 20°C which corresponds to a restricted number of isoenzymes. In isolated embryos the peroxidase activity increases significantly. This is due to an increase in both the number and the activity of the isoperoxidases and it is more pronounced at 20°C than at 5°C. The obtained results suggest that the soluble peroxidases are not involved in the process of the release of embryo dormancy. The variations observed are attributed to the growth process following germination, which can occur even at low temperature.     

Dissociation of intracellular lysosomal rupture from the cell death caused by silica

The relationship between intracellular lysosomal rupture and cell death caused by silica was studied in P388d(1) macrophages. After 3 h of exposure to 150 μg silica in medium containing 1.8 mM Ca(2+), 60 percent of the cells were unable to exclude trypan blue. In the absence of extracellular Ca(2+), however, all of the cells remained viable. Phagocytosis of silica particles occurred to the same extent in the presence or absence of Ca(2+). The percentage of P388D(1) cells killed by silica depended on the dose and the concentration of Ca(2+) in the medium. Intracellular lyosomal rupture after exposure to silica was measured by acridine orange fluorescence or histochemical assay of horseradish peroxidase. With either assay, 60 percent of the cells exposed to 150 μg silica for 3 h in the presence of Ca(2+) showed intracellular lysosomal rupture, was not associated with measureable degradation of total DNA, RNA, protein, or phospholipids or accelerated turnover of exogenous horseradish peroxidase. Pretreatment with promethazine (20 μg/ml) protected 80 percent of P388D(1) macrophages against silica toxicity although lysosomal rupture occurred in 60-70 percent of the cells. Intracellular lysosomal rupture was prevented in 80 percent of the cells by pretreatment with indomethacin (5 x 10(-5)M), yet 40-50 percent of the cells died after 3 h of exposure to 150 μg silica in 1.8 mM extracellular Ca(2+). The calcium ionophore A23187 also caused intracellular lysosomal rupture in 90-98 percent of the cells treated for 1 h in either the presence or absence of extracellular Ca(2+). With the addition of 1.8 mM Ca(2+), 80 percent of the cells was killed after 3 h, whereas all of the cells remained viable in the absence of Ca(2+). These experiments suggest that intracellular lysosomal rupture is not causally related to the cell death cause by silica or {"type":"entrez-nucleotide","attrs":{"text":"A23187","term_id":"833253","term_text":"A23187"}}A23187. Cell death is dependent on extracellular Ca(2+) and may be mediated by an influx of these ions across the plasma membrane permeability barrier damaged directly by exposure to these toxins.     

A covalently bound photoisomerizable agonist. Comparison with reversibly bound agonists at electrophorus electroplaques

After disulphide bonds are reduced with dithiothreitol, trans-3- (α-bromomethyl)-3’-[α- (trimethylammonium)methyl]azobenzene (trans-QBr) alkylates a sulfhydryl group on receptors. The membrane conductance induced by this “tethered agonist” shares many properties with that induced by reversible agonists. Equilibrium conductance increases as the membrane potential is made more negative; the voltage sensitivity resembles that seen with 50 [mu]M carbachol. Voltage- jump relaxations follow an exponential time-course; the rate constants are about twice as large as those seen with 50 μM carbachol and have the same voltage and temperature sensitivity. With reversible agonists, the rate of channel opening increases with the frequency of agonist-receptor collisions: with tethered trans-Qbr, this rate depends only on intramolecular events. In comparison to the conductance induced by reversible agonists, the QBr-induced conductance is at least 10-fold less sensitive to competitive blockade by tubocurarine and roughly as sensitive to “open-channel blockade” bu QX-222. Light-flash experiments with tethered QBr resemble those with the reversible photoisomerizable agonist, 3,3’,bis-[α-(trimethylammonium)methyl]azobenzene (Bis-Q): the conductance is increased by cis {arrow} trans photoisomerizations and decreased by trans {arrow} cis photoisomerizations. As with Bis-Q, ligh-flash relaxations have the same rate constant as voltage-jump relaxations. Receptors with tethered trans isomer. By comparing the agonist-induced conductance with the cis/tans ratio, we conclude that each channel’s activation is determined by the configuration of a single tethered QBr molecule. The QBr-induced conductance shows slow decreases (time constant, several hundred milliseconds), which can be partially reversed by flashes. The similarities suggest that the same rate-limiting step governs the opening and closing of channels for both reversible and tethered agonists. Therefore, this step is probably not the initial encounter between agonist and receptor molecules.     

Chromatin structure visualization by immunoelectron microscopy

Antibodies elicited in rabbits by chromatin and by purified histone H2B have been used to study the structure of chromatin by immunoelectron microscopy. Chromatin spread on grids reveals a structure of closely packed spherical particles with an average diameter of 104 Å, arranged either in clusters or in linear arrays of beads, some of which have a supercoil-like arrangement. No DNA strings connecting the beads could be observed. Upon antibody binding, the diameter of the particles increases up to 300 Å. This size is compatible with a model where one layer of gamma globulin molecules 110 Å long encircles a sphere of chromatin 100 Å in diameter. The presence of rabbit gamma globulins on the enlarged beads has been verified by the addition of ferritin-labeled goat anti-rabbit gamma globulins. Anti-chromatin sera which react with nonhistone proteins but not with free histones or DNA react with more than 95% of the beads; this suggests that most of the beads contain nonhistone proteins. Since the number of nonhistone proteins is large, it is improbable that each sphere contains a full complement of these proteins. We therefore suggest that the various chromatin spheres contain different types of nonhistone proteins. About 90% of the chromatin spheres reacted with antibodies to histone H2B, suggesting that most of the chromatin beads contain this type of histone.     

Revision of the bulbous Iridaceae of North America

The native bulbous Iridaceae of North America excluding Mexico comprise seven species in four genera. The type species ofAlophia Herb. (1836) is shown to belong toEustylis Engelm. & Gray (1836), hence the latter genus is reduced to synonymy. The well known genusAlophia (sensu auct. non Herb.) (Herbertia Sweet) now takes the nameTrifurcia. As a result of the new interpretation ofAlophia, new combinations are made for the North American and Latin American species ofTrifurcia andAlophia. New chromosome counts are given forNemastylis floridana (2n = 56) andTrifurcia lahue (2n = 56).     

Exposure of histone antigenic determinants in chromatin.

The exposure of antigenic determinants of histones present in "native" chromatin was studied by: (1) testing their ability to elicit anti-histone antibodies and (2) measuring their ability to interact with anti-histone sera. To this end, antisera specific to purified histone fractions and to purified rat liver chromatin were elicited in rabbits. The anti-chromatin sera did not react with pure histone fractions and pure histone fractions F2b, F3, F2a1, and F2a2 failed to inhibit the complement fixation resulting from the binding of anti-chromatin to chromatin. These results suggest that in native chromatin, determinants in these histones are not immunogenic. Histone F1, however, inhibited the reaction between chromatin and anti-chromatin. Antisera elicited by histone fractions reacted weakly with "native" chromatin. The maximal complement fixations (obtained with 5-10 mug of chromatin DNA) were as follows: 60% with anti-F2b, 20% with anti-F1 and anti-F3, and less than 5% with either anti-F2a1 or anti-F2a2. Studies of the interaction between anti-histone antibodies and chromatin in which chromatin was used as an immunoadsorbent indicated that antibodies against different histones were adsorbed to a different degree by the same amount of chromatin. Differences in the immunoadsorbing capacity between sonicated and nonsonicated chromatin were found. Quantitative adsorbtion studies revealed that in the "native" chromatin structure, antigenic determinants of F1 and F2b were more available to interact with homologous antibody than those of F3 and F2a1 and that determinants in F2a2 were the least available. It could be calculated that the "equivalent antigenicity" of the histones in chromatin was 9.6% for F1, 3.2% for F2b, and 0.90% for F3 and F2a1. Upon sonication these values did not change for F1 but increased two-, three-, and fourfold for F2b, F3, and F2a1, respectively. Digestion of chromatin with trypsin totally abolished the ability of chromatin to adsorb anti-histone antibodies.