An Emerging Approach for Parallel Quantification of Intracellular Protozoan Parasites and Host Cell Characterization Using TissueFAXS Cytometry

Characterization of host-pathogen interactions is a fundamental approach in microbiological and immunological oriented disciplines. It is commonly accepted that host cells start to change their phenotype after engulfing pathogens. Techniques such as real time PCR or ELISA were used to characterize the genes encoding proteins that are associated either with pathogen elimination or immune escape mechanisms. Most of such studies were performed in vitro using primary host cells or cell lines. Consequently, the data generated with such approaches reflect the global RNA expression or protein amount recovered from all cells in culture. This is justified when all host cells harbor an equal amount of pathogens under experimental conditions. However, the uptake of pathogens by phagocytic cells is not synchronized. Consequently, there are host cells incorporating different amounts of pathogens that might result in distinct pathogen-induced protein biosynthesis. Therefore, we established a technique able to detect and quantify the number of pathogens in the corresponding host cells using immunofluorescence-based high throughput analysis. Paired with multicolor staining of molecules of interest it is now possible to analyze the infection profile of host cell populations and the corresponding phenotype of the host cells as a result of parasite load.     

Reconstructing labroid evolution with single-copy nuclear DNA.

Fifteen per cent of all living fishes are united in a single suborder (Labroidei) and display a dazzling array of behavioural and ecological traits. The labroids are considered monophyletic and members share a pharyngeal jaw apparatus (PJA) modified for crushing and processing prey. Outside of the explicitly functional PJA, there is no corroborative evidence for a monophyletic Labroidei. Here, we report the first molecular phylogenetic analysis of the suborder. Contrary to morphology-based phylogenies, our single-copy nuclear DNA data do not support labroid families as a natural group. Our data indicate that pharyngognathy has evolved independently among labroid families and that characters of the PJA are not reliable markers of perciform evolution. This work ''crushes'' conventional views of fish phylogeny and should engender novel concepts of piscine life history evolution.     

Trace elements in rock salt and their bioavailability estimated from solubility in acid

In this study, 18 partly commercially available samples of rock salt from Austria, Germany, Pakistan, Poland, Switzerland, and Ukraine were investigated with respect to their content of trace elements using instrumental neutron activation analysis. Elements detected were Al, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Eu, Fe, Hf, La, Mn, Na, Rb, Sb, Sc, Sm, Sr, Ta, Tb, Th, and Zn, some of them only in individual cases. An estimation of the bioavailability of these trace elements was performed by dissolving an equivalent of the sodium chloride samples in diluted hydrochloric acid (simulating stomach acid), filtering off the insoluble components, and analyzing the evaporated filtrate. It could be shown that in most cases bioactive trace elements like Fe can be found in rock salt in the form of almost insoluble compounds and are therefore not significantly bioavailable, whereas thorium, for example, was partly bioavailable in two cases. A significant contribution to the recommended daily intake of metal trace elements by using rock salt for nutrition can be excluded.     

Interactions in hypoxic and hypercapnic breathing are genetically linked to mouse chromosomes 1 and 5.

The genetic basis for differences in the regulation of breathing is certainly multigenic. The present paper builds on a well-established genetic model of differences in breathing using inbred mouse strains. We tested the interactive effects of hypoxia and hypercapnia in two strains of mice known for variation in hypercapnic ventilatory sensitivity (HCVS); i.e., high gain in C57BL/6J (B6) and low gain in C3H/HeJ (C3) mice. Strain differences in the magnitude and pattern of breathing were measured during normoxia [inspired O(2) fraction (Fi(O(2))) = 0.21] and hypoxia (Fi(O(2)) = 0.10) with mild or severe hypercapnia (inspired CO(2) fraction = 0.03 or 0.08) using whole body plethysmography. At each level of Fi(O(2)), the change in minute ventilation (Ve) from 3 to 8% CO(2) was computed, and the strain differences between B6 and C3 mice in HCVS were maintained. Inheritance patterns showed potentiation effects of hypoxia on HCVS (i.e., CO(2) potentiation) unique to the B6C3F1/J offspring of B6 and C3 progenitors; i.e., the change in Ve from 3 to 8% CO(2) was significantly greater (P < 0.01) with hypoxia relative to normoxia in F1 mice. Linkage analysis using intercross progeny (F2; n = 52) of B6 and C3 progenitors revealed two significant quantitative trait loci associated with variable HCVS phenotypes. After normalization for body weight, variation in Ve responses during 8% CO(2) in hypoxia was linked to mouse chromosome 1 (logarithm of the odds ratio = 4.4) in an interval between 68 and 89 cM (i.e., between D1Mit14 and D1Mit291). The second quantitative trait loci linked differences in CO(2) potentiation to mouse chromosome 5 (logarithm of the odds ratio = 3.7) in a region between 7 and 29 cM (i.e., centered at D5Mit66). In conclusion, these results support the hypothesis that a minimum of two significant genes modulate the interactive effects of hypoxia and hypercapnia in this genetic model.