The "framing" of benefit (or risk) in relative versus absolute terms may have a major influence on patient preference.

NK and LAK cells, through the use of immune biologic modifiers, have been demonstrated to have a therapeutic role in the treatment of human cancers. Further studies are required to determine the optimal dosages and combinations of chemotherapeutic agents, the timing of surgery, and the adjuvant use of immune biologic response modifiers. An increasing awareness and understanding of this field, may allow for the future development of anti-cancer therapies.

Studies of the distribution of ammonia oxidising archaea (AOA) and bacteria (AOB) suggest distinct ecological niches characterised by ammonia concentration and pH, arising through differences in substrate affinity and ammonia tolerance. AOA form five distinct phylogenetic clades, one of which, the ‘Nitrososphaera sister cluster’, has no cultivated isolate. A representative of this cluster, named ‘Candidatus Nitrosocosmicus franklandus’, was isolated from a pH 7.5 arable soil and we propose a new cluster name: ‘Nitrosocosmicus’. While phylogenetic analysis of amoA genes indicates its association with the Nitrososphaera sister cluster, analysis of 16S rRNA genes provided no support for a relative branching that is consistent with a ‘sister cluster’, indicating placement within a lineage of the order Nitrososphaerales. ‘Ca. N. franklandus’ is capable of ureolytic growth and its tolerances to nitrite and ammonia are higher than in other AOA and similar to those of typical soil AOB. Similarity of other growth characteristics of ‘Ca. N. franklandus’ with those of typical soil AOB isolates reduces support for niche differentiation between soil AOA and AOB and suggests that AOA have a wider physiological diversity than previously suspected. In particular, the high ammonia tolerance of ‘Ca. N. franklandus’ suggests potential contributions to nitrification in fertilised soils.

Autotrophic ammonia oxidation is performed by two distinct groups of microorganisms: ammonia-oxidising archaea (AOA) and ammonia-oxidising bacteria (AOB). AOA outnumber their bacterial counterparts in many soils, at times by several orders of magnitude, but relatively little is known of their physiology due to the lack of cultivated isolates. Although a number of AOA have been cultivated from soil, Nitrososphaera viennensis was the sole terrestrial AOA in pure culture and requires pyruvate for growth in the laboratory. Here, we describe isolation in pure culture and characterisation of two acidophilic terrestrial AOA representing the Candidatus genus Nitrosotalea and their responses to organic acids. Interestingly, despite their close phylogenetic relatedness, the two Nitrosotalea strains exhibited differences in physiological features, including specific growth rate, temperature preference and to an extent, response to organic compounds. In contrast to N. viennensis, both Nitrosotalea isolates were inhibited by pyruvate but their growth yield increased in the presence of oxaloacetate. This study demonstrates physiological diversity within AOA species and between different AOA genera. Different preferences for organic compounds potentially influence the favoured localisation of ammonia oxidisers within the soil and the structure of ammonia-oxidising communities in terrestrial ecosystems.

Components of excitation-contraction (E-C) coupling were compared in ventricular myocytes isolated from 3-mo-old male and female rats. Ca(2+) concentrations (fura-2) and cell shortening (edge detector) were measured simultaneously (37 degrees C). Membrane potential and ionic currents were measured with microelectrodes. Action potentials were similar in male and female myocytes, but contractions were smaller and slower in females. In voltage-clamped cells, peak contractions were smaller in females than in males (5.1 +/- 0.7% vs. 7.7 +/- 0.8% diastolic length, P < 0.05). Similarly, Ca(2+) transients were smaller in females than in males and the rate of rise of the Ca(2+) transient was slower in females. Despite smaller contractions and Ca(2+) transients in females, Ca(2+) current density was similar in both groups. Sarcoplasmic reticulum Ca(2+) content, assessed with caffeine, did not differ between the sexes. However, E-C coupling gain (rate of Ca(2+) release/Ca(2+) current) was smaller in females than in males (157.0 +/- 15.6 vs. 338.4 +/- 54.3 (nM/s)/(pA/pF), P < 0.05). To determine whether the reduced gain in female cells was due to changes in unitary Ca(2+) release, spontaneous Ca(2+) sparks were evaluated (fluo-4, 37 degrees C). Spark frequencies and widths were similar in both groups, but spark amplitudes were smaller in females than in males (0.56 +/- 0.01 vs. 0.64 +/- 0.01 DeltaF/F(0), P < 0.05). Spark durations also were shorter in females than in males (full duration at half-maximum = 14.86 +/- 0.17 vs. 16.25 +/- 0.27 ms, P < 0.05). These observations suggest that decreases in the size and duration of Ca(2+) sparks contributes to the decrease in E-C coupling gain in female myocytes. Thus, differences in cardiac contractile function arise, in part, from differences in unitary Ca(2+) release between the sexes.