Measurement of the humoral immune response against Streptococcus pneumoniae type 14-derived antigens by an ELISA and ELISPOT assay based on biotin-avidin technology.

A Streptococcus pneumoniae type 14-specific ELISA and ELISPOT assay have been developed based on the use of biotinylated type 14 capsular polysaccharide (S14PS-biotin). A major advantage of this application over other methods is the use of 10-100-fold less antigen than that reported in the literature for other similar assays. Moreover, the prepared biotinylated polysaccharides are very stable and it is possible to use the same procedures for other pneumococcal polysaccharide antigens (e.

Nonionic block polymer surfactants enhance the avidity of antibodies in polyclonal antisera against Streptococcus pneumoniae type 3 in normal and Xid mice.

Avidities of antibody (sub)classes in polyclonal antisera against Streptococcus pneumoniae type 3 (S3) can be (semi) quantitatively determined with a specific inhibition ELISA. A hexasaccharide was isolated from the hydrolyzed S3 capsular polysaccharide and coupled to a protein-carrier. Mixtures containing these conjugates and nonionic block polymer (NBP) surfactants were used for immunization.

Nonionic block polymer surfactants modulate the humoral immune response against Streptococcus pneumoniae-derived hexasaccharide-protein conjugates.

Nonionic block polymer surfactants (NBPs) were tested for the capacity to stimulate the antibody response against hexasaccharide (HS), derived from Streptococcus pneumoniae type 3 capsular polysaccharide (S3PS), which was conjugated to proteins. The immune response was evaluated in the (CBA/N x BALB/c)F1 progeny, in which female mice are phenotypically normal whereas male mice carry an X-chromosome-linked immunodeficiency. NBPs L101, L121, 1101, and 1501 were able to increase anti-HS immunoglobulin M (IgM) and IgG levels in both normal and X-chromosome-linked immunodeficient mice (with up to 74-fold stimulation of antibody titers).

Plasma profiles of fourteen ovarian steroids before, during and after ovulation in African catfish,Clarias gariepinus, determined by gas chromatography and mass spectrometry.

The plasma concentrations of fourteen ovarian steroids were measured in postvitellogenic African catfish,Clarias gariepinus, which had been injected with pimozide and LHRHa. Postvitellogenesis persisted for at least four hours after pimozide and LHRHa administration. During this stage a limited rise in the plasma gonadotropin (GTH) level was accompanied by an increase in the testosterone concentration.

Estimation of the avidity of antibodies in polyclonal antisera against Streptococcus pneumoniae type 3 by inhibition ELISA.

The reliability of the determination of antibody avidity in polyclonal sera by indirect sandwich ELISA was studied. Binding of IgM and IgG (sub)classes in unpurified serum to Streptococcus pneumoniae type 3 capsular polysaccharide, which was coated onto ELISA plates, was inhibited with different inhibitors. The inhibitor concn at which 50% inhibition of antibody binding to the ELISA coat was achieved, was used as a measure for antibody avidity.

5 beta-pregnane-3 alpha,6 alpha,17 alpha,20 beta-tetrol and 5 beta-pregnane-3 alpha,6 alpha,17 alpha-triol-20-one: steroids of ovarian origin in the African catfish, Clarias gariepinus, during oocyte maturation.

At the stage of oocyte maturation, three very polar steroids were demonstrated by in vitro incubations with tritiated pregnenolone in the ovaries of the African catfish, Clarias gariepinus. Two of these compounds could be identified by chromatography, derivatization, and oxidation as 5 beta-pregnane-3 alpha,6 alpha,17 alpha,20 beta-tetrol and 5 beta-pregnane-3 alpha,6 alpha,-17 alpha-triol-20-one. Blood plasma analysis by means of gas chromatography followed by mass spectrometry confirmed the presence of these steroids with selected ion monitoring.

The Influence of Embellishment and Prequestions on Free Recall of a Text.

The influence on free recall of the addition of embellishing details to the constituent scenes of a text was studied as a function of the salience of the embellished scenes within the overall content. The relative salience of the scenes that occupied odd- or even-numbered serial positions was varied by introduction of prequestions. In Experiment 1 (n = 52), the effectiveness of the prequestions was tested, in Experiment 2 (n = 48), the presentation of prequestions was combined orthogonally with embellishment of the scenes.

The influence of the labeling of pictures of "borderline meaningfulness" on recall and recognition.

An attempt was made to enhance (by means of instruction) the verbal labeling and recall of schematic pictures which uninformed Ss tended to perceive as senseless. Sixty-nine male and female undergraduate students in psychology, about 19 years of age, took part in the experiment. Ss were confronted with 16 schematic pictures half of which referred to a predefined semantical category.

Test expectancy and encoding of pictures and words.

Undergraduates were shown pictures or corresponding labels and then were tested for recognition either in the same mode or in a cross-over mode. Significantly more items were recognized in the picture-picture condition than in the picture-word and word-picture conditions. Informing subjects in advance of the change in modality significantly improved picture-word performance.

Incidental cues and picture/word differences in recall.

80 university undergraduates attempted free recall of 20 objects presented as either (a) normally printed words, (b) words enriched with iconic sign characteristics, (c) normal line drawings, or (d) schematic line drawings constructed from a limited set of elements. Enriched words were better recalled than normal words, whereas differences in recall between the two types of line drawings just failed to reach significance. The results were discussed in reference to the dual coding- and incidental-cue hypothesis.