From Mesolithic hunters to Iron Age herders: a unique record of woodland use from eastern central Europe (Czech Republic)

Vegetation History and Archaeobotany - In a continuous, perfectly stratified sedimentary sequence which was discovered under a large sandstone overhang in northern Bohemia, Czech Republic, we...     

Immunomodulatory cytokines in human seminal plasma correlate with immunomodulatory steroids

7alpha-Hydroxy-dehydroepiandrosterone and its 7beta-hydroxyepimer, which act as local immunomodulatory agents, dehydroepiandrosterone, cortisol, and major androgens, together with four cytokines-interleukins 2, 4, 10, and IFN-gamma, reflecting the activity of TH1 or TH2 cells present in semen, were measured in seminal plasma from 35 male donors. Cortisol, dehydroepiandrosterone, its sulfate, 7-hydroxy-dehydroepiandrosterone epimers, testosterone, and estradiol were also measured in their blood serum. Steroids and interleukins in semen as well as serum steroids and seminal interleukins were mutually correlated to find out whether a relationship between immunomodulatory steroids and cytokines influencing the immune environment does exist. A highly significant (P<0.001) positive correlation was found between seminal 7beta-hydroxy-dehydroepiandrosterone and IFN-gamma, while a negative correlation was found between cortisol and IL-10. Highly significant positive correlations were also found between serum 7alpha-hydroxy-dehydroepiandrosterone and seminal IFN-gamma and between serum 7beta-hydroxy-dehydroepiandrosterone and seminal IL-2, while a negative correlation was found between serum dehydroepiandrosterone and seminal IL-10. Different and in some instances, even contradictory findings concerning the influence of dehydroepiandrosterone and cortisol on TH1 and TH2 cytokines were observed in seminal plasma as compared to those found by others in serum. The differences can be ascribed to the different environments of mucosal and systemic immunity. Correlations between the levels of steroids and cytokines in seminal plasma did not always correspond to the correlations between given cytokines and hormones in sera. The results, however, are in agreement with our recent finding of an autonomous production of these steroids in the male reproductive tract.     

Isoform‐specific cleavage of 14‐3‐3 proteins in apoptotic JURL‐MK1 cells

The proteins of 14‐3‐3 family are substantially involved in the regulation of many biological processes including the apoptosis. We studied the changes in the expression of five 14‐3‐3 isoforms (β, γ, ε, τ, and ζ) during the apoptosis of JURL‐MK1 and K562 cells. The expression level of all these proteins markedly decreased in relation with the apoptosis progression and all isoforms underwent truncation, which probably corresponds to the removal of several C‐terminal amino acids. The observed 14‐3‐3 modifications were partially blocked by caspase‐3 inhibition. In addition to caspases, a non‐caspase protease is likely to contribute to 14‐3‐3's cleavage in an isoform‐specific manner. While 14‐3‐3 γ seems to be cleaved mainly by caspase‐3, the alternative mechanism is essentially involved in the case of 14‐3‐3 τ, and a combined effect was observed for the isoforms ε, β, and ζ. We suggest that the processing of 14‐3‐3 proteins could form an integral part of the programmed cell death or at least of some apoptotic pathways. J. Cell. Biochem. 106: 673–681, 2009. © 2009 Wiley‐Liss, Inc.     

Does Threat to the Nest Affect Incubation Rhythm in a Small Passerine?

Nest predation is a crucial factor influencing breeding success in birds. One possible way to protect nests is to modify parental activity in the vicinity of the nest. Here, we provide experimental evidence for an adjustment of incubation pattern during periods when there is an increased risk of nest predation in a small passerine. We compared the behaviour of incubating meadow pipit (Anthus pratensis) females during presentations of stuffed dummies of a nest predator (the magpie Pica pica) and a harmless intruder (the crossbill Loxia curvirostra) and during an undisturbed control incubation period. Females significantly decreased their activity in the presence of the nest predator. Specifically, after being flushed out, they returned to the nest later and moved to and from the nest less than when the harmless intruder was present. These results document the ability of birds to assess the nest predation risk and adjust their appropriate incubation strategy.     

Lipid-gramicidin interactions: dynamic structure of the boundary lipid by 2D-ELDOR

The use of 2D-electron-electron double resonance (2D-ELDOR) for the characterization of the boundary lipid in membrane vesicles of DPPC and gramicidin A' (GA) is reported. We show that 2D-ELDOR, with its enhanced spectral resolution to dynamic structure as compared with continuous-wave electron spin resonance, provides a reliable and useful way of studying lipid-protein interactions. The 2D-ELDOR spectra of the end-chain spin label 16-PC in DPPC/GA vesicles is composed of two components, which are assigned to the bulk lipids (with sharp auto peaks and crosspeaks) and to the boundary lipids (with broad auto peaks). Their distinction is clearest for higher temperatures and higher GA concentrations. The quantitative analysis of these spectra shows relatively faster motions and very low ordering for the end chain of the bulk lipids, whereas the boundary lipids show very high "y-ordering" and slower motions. The y-ordering represents a dynamic bending at the end of the boundary lipid acyl chain, which can then coat the GA molecules. These results are consistent with the previous studies by Ge and Freed (1999) using continuous-wave electron spin resonance, thereby supporting their model for GA aggregation and H(II) phase formation for high GA concentrations. Improved instrumental and simulation methods have been employed.     

Variation in DNA-ploidy Levels of Reynoutria Taxa in the Czech Republic

The genus Reynoutria is represented by four taxa in the Czech Republic: Reynoutria japonica var. japonica, R. japonica var. compacta, R. sachalinensis and R. xbohemica. By using flow cytometry, cytological variability within the genus is described based on 257 Reynoutria samples. The varieties of R. japonica are cytologically uniform, var. japonica is exclusively octoploid (2n = 8x = 88) and var. compacta occurs only as a tetraploid (2n = 4x = 44), but R. sachalinensis and R. xbohemica exhibit some variation in chromosome numbers. Reynoutria sachalinensis is predominantly tetraploid (2n = 4 x = 44), but also occurs occasionally as hexaploid and octoploid cytotypes. The most common ploidy level in R. xbohemica is hexaploid (2n = 6x = 66), but tetraploid and octoploid clones were also found. The four taxa occurring in the Czech Republic are described briefly and the possible origins of the cytotypes discussed.