Heat-labile opsonins to pneumococci in normal mammalian sera, unlike antibodies, fail to interact with the bacteria at 0 degrees C and require Ca(++) and/or Mg(++). They are readily removed from serum by antigen-antibody complexes that fix complement (C) and are inhibited by reagents that inactivate various C components. The principal heat-labile opsonin to pneumococci is activated C3 (C3(b)), ...

The DNA labile sites induced by two nitrosoureas, nimustine (ACNU) and ramustine (MCNU) synthesised in Japan, have been examined in highly reiterated DNA sequences of rat glioma cells. Reiterated fragments of 167 and 203 base pairs (bp), obtained after Hind III and Hae III restriction endonuclease digestion of rat glioma cells DNA, were used as target DNA sequences to determine the labile sites...

We assessed the role of the cell labile iron pool in mediating oncogene-induced cell proliferation via repression of ferritin expression. When HEK-293 cells, engineered to inducibly express either active (+) or dominant-negative (-) forms of the H-ras oncogene, were treated with antisense nucleotides to ferritin subunits they displayed (a) decreased ferritin levels, (b) increased labile iron po...

In serum there are two classes of hexosaminidase. One of these is heat-labile and is inactive in children with Tay-Sachs disease. Serum from heterozygotes for Tay-Sachs disease has half the normal activity of the heat-labile enzyme. The heat-labile enzyme can be inactivated by heating serum diluted in buffer for 5 mm at 60 #{176}C. We have used this property to develop a reliable, fully automat...

Labile metal complexes have a useful coordination bond; which is weaker than a covalent C–C bond and is reversibly and dynamically formed and dissociated. Such labile metal complexes also can be used to construct chiral shapes and offer dynamic conversion of chiral molecular shapes in response to external stimuli. This review provides recent examples of chirality induction and describes the dyn...

We have devised a rapid and convenient method of eliminating the contribution of labile glycosylated hemoglobin in the hemoglobin A1 assay. The procedure requires a 30-min incubation of erythrocytes in 30 mM semicarbazide and 12 mM aniline (pH 5, 38 degrees C). This chemical means of eliminating the labile fraction is as effective as a 14-h incubation in isotonic saline as measured with high-pr...

Chemical extractants used to measure labile soil metal must ideally select for and solubilise the labile fraction, with minimal solubilisation of non-labile metal. We assessed four extractants (0.43 M HNO3, 0.43 M CH3COOH, 0.05 M Na2H2EDTA and 1 M CaCl2) against these requirements. For soils contaminated by contrasting sources, we compared isotopically exchangeable Ni, Cu, Zn, Cd and Pb (EValue...