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641.
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The synthesis of the esters of norethisterone (17α-ethynyl-l7β-hydroxyestr-4-en-3-one) with three bile acids and of the cholesteryl carbonate of norethisterone are described. 相似文献
643.
J. A. Sandoval F. X. Côte J. Escoute 《In vitro cellular & developmental biology. Plant》1996,32(1):14-17
Summary The objective of the present study on banana plants (Musa AAA Grande Naine cv.), obtained byin vitro shoot tip culture, was to determine whether modifications in chromosome number could account for the appearance of the off-types
with mosaiclike leaf defects or dwarf stature, the most frequent off-types observed after micropropagation. Chromosome counts
were conducted on shoot tip samples treated with 8-hydroxyquinoline, digested in pectinase and stained with Schiff's reagent.
On average, 160 counts were made for each treatment. Four types of plant material were studied: phenotypically true-to-type
plants, dwarf off types, mosaiclike off-types obtained by micropropagation, as well as true-to-type plants obtained by standard
propagation techniques of suckers with no micropropagation history. Some cells from all four types of plant material were
found to have an abnormal chromosome number (i.e., 2n = 3x = 33), characteristic of triploid banarias. The percentages of
aneuploid cells were 14%, 22%, 35%, and 5%, respectively. Descending aneuploidy was noted in micropropagated plants derived
from true-to-type and dwarf off-type suckers. The statistical analysis revealed that the two latter types of plant material
had the same percentage of aneuploid cells. Thus, the dwarfism could not be correlated with a change in the chromosome number.
Conversely, ascending aneuploidy was observed in the mosaiclike material, with 34 or 35 chromosomes in almost 28% of the cells.
This percentage was significantly higher than in true-to-type plants and highlight the genetic origin of the mosaiclike variation. 相似文献
644.
M C Contreras L Sandoval P Salinas P Mu?oz S Vargas 《Boletín chileno de parasitología》2000,55(1-2):17-24
Toxoplasmosis, a world-wide zoonotic infection, is generally asymptomatic and benign in immunocompetent individuals, but it can be serious in immunodeficiencies particularly in patients with acquired immunodeficiency syndrome and in children infected in utero. So, it is important to dispose methods which permit discriminate between recent and chronic infections. In order to contribute to improve the diagnosis of toxoplasmosis ELISA IgG, IgM, IgA and ELISA IgG avidity were performed in 15 and 24 sera from patients suspected of having acute and chronic infection respectively, according dye test (DT) titres. ELISA IgG was positive in both groups, ELISA IgM was positive in 78.6 and 58.3% respectively, while ELISA IgA was positive in 85.7 and 33.3% of recent and chronic group respectively. In those sera with low IgG avidity (18.8%) we found specific IgM in 71.5 and 4.2% and IgA in 78.6 and 0.0% of recent and chronic groups respectively. Parallelling, 208 sera samples were classified according to the results of DT, indirect hemagglutination and complement fixation tests in the following groups: acute (97), intermediate (36), chronic (35) and negative (40). The results were: acute (96.9-64.9-55.6 and 65.9%); intermediate (97.2-63.8-44.4 and 47.2%); chronic (45.7-42.8-5.7 and 34.3%) for IgG, IgM, IgA and low IgG avidity respectively. The use of both acute markers, IgA and low IgG avidity in the diagnosis of toxoplasmosis is discussed. 相似文献
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