Pathways involved in alanyl-glutamine-induced changes in neutrophil amino- and α-keto acid homeostasis or immunocompetence

Summary. We examined the effects of DON [glutamine-analogue and inhibitor of glutamine-requiring enzymes], alanyl-glutamine (regarding its role in neutrophil immunonutrition) and alanyl-glutamine combined with L-NAME, SNAP, DON, β-alanine and DFMO on neutrophil amino and α-keto acid concentrations or important neutrophil immune functions in order to establish whether an inhibitor of •NO-synthase [L-NAME], an •NO donor [SNAP], an analogue of taurine and a taurine transport antagonist [β-alanine], an inhibitor of ornithine-decarboxylase [DFMO] as well as DON could influence any of the alanyl-glutamine-induced effects. In summary, irrespective of which pharmacological, metabolism-inhibiting or receptor-mediated mechanisms were involved, our results showed that impairment of granulocytic glutamine uptake, modulation of intracellular glutamine metabolisation and/or de novo synthesis as well as a blockade of important glutamine-dependent metabolic processes may led to significant modifications of physiological and immunological functions of the affected cells.     

Pathway analysis identifies perturbation of genetic networks induced by butyrate in a bovine kidney epithelial cell line

Ruminant species have evolved to metabolize the short-chain volatile fatty acids (VFA), acetate, propionate, and butyrate, to fulfill up to 70% of their nutrient energy requirements. The inherent VFA dependence of ruminant cells was exploited to add a level of increased sensitivity to the study of the role of butyrate gene-response elements in regulatory biochemical pathways. Global gene expression profiles of the bovine kidney epithelial cells regulated by sodium butyrate were investigated with high-density oligonucleotide microarrays. The detailed mechanisms by which butyrate induces cell growth arrest and apoptosis were analyzed using the Ingenuity Pathways Knowledge Base. The functional category and pathway analyses of the microarray data revealed that four canonical pathways (Cell cycles: G2/M DNA damage checkpoint, and pyrimidine metabolism; G1/S checkpoint regulation and purine metabolism) were significantly perturbed. The biologically relevant networks and pathways of these genes were also identified. IGF2, TGFB1, TP53, E2F4, and CDC2 were established as being centered in these genomic networks. The present findings provide a basis for understanding the full range of the biological roles and the molecular mechanisms that butyrate may play in animal cell growth, proliferation, and energy metabolisms. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. Mention of trade names or commercial products in this publication is solely for providing specific information and does not imply recommendation or endorsement by the US Department of Agriculture.     

Development of distylous flowers and investment of biomass in male and female function in Palicourea padifolia (Rubiaceae)

Knowledge of developmental pathways for achieving differences in style and anther heights, in concert with those of ancillary features accompanied with data in regard to biomass investment to male and female function, provide an excellent opportunity for examining the developmental correlations between primary and ancillary floral traits so as to understand the evolution of heterostyly. The ontogenetic relationships between bud length and anther height and between bud length and style height, and between bud length versus bud width, anther length, and number of pollen grains per anther for long-styled (LS) and short-styled (SS) morphs of P. PADIFOLIA are described. We also described the ontogenetic biomass allocation to male and female function and to corolla with elongation of buds harvested at regular intervals. We observed an early termination of stylar growth in SS buds, whereas LS styles steadily increased in size. Morph differences for relative growth rates were significant for anther height, anther length, and pollen number but not for bud width. Bud width and anther length had a negative allometric relationship with bud elongation. The relationship between bud length and number of pollen grains per anther was positive and morph differences in pollen number were detected at later stages of development. An increase in corolla mass involved a disproportionate allocation to the female function in SS flowers and male allocation was similar for the two morphs over the course of development. Our results are consistent with theoretical and empirical data for distylous species with an approach herkogamous ancestor, and with the more general hypothesis of ontogenetic lability of heterostyly, in which morph differences in style and anther heights are achieved in various ways. Variations observed in sexual investment between floral morphs suggest differences in sex expression during flower development.     

Vertebrate aging research 2006

This Hot Topics review, the first in a projected annual series, discusses those articles, published in the last year, which seem likely to have a major impact on our understanding of the aging process in mammals and the links between aging and late-life illnesses. The year's highlights include studies of oxidation damage in the very-long-lived naked mole-rat, and of caloric restriction in monkeys, humans, and growth hormone-unresponsive mice. Two studies of resveratrol, one showing its ability to extend lifespan in a short-lived fish, the other demonstrating beneficial effects in mice subjected to a diet high in fat, may well be harbingers of a parade of intervention studies in the coming decade.     

Spatial patterns on the sagebrush steppe/Western juniper ecotone

Analysis of the spatial patterns of woody plants is important to better understand the ecological processes that govern the worldwide expansion of woody plants across semi-arid ecosystems. Second-order characteristics of a marked spatial point pattern of western juniper (Juniperus occidentalis subsp. occidentalis) were analyzed using Ripley’s K-functions and the pair-correlation function g. The marked point process of crown diameters was produced via two-dimensional wavelet analysis of a fine scale aerial photograph at the woodland-steppe ecotone in the Reynolds Creek watershed in the Owyhee Mountains, southwestern Idaho. Colonization of J. occidentalis stems from mature juniper trees growing in rocky, fire resistant areas. Although these areas introduce components of natural heterogeneity within the landscape, the selected study area is situated within a single soil type, and we modeled the expansion of juniper plants into previously juniper-free sagebrush steppe as a homogeneous point process with constant intensity. Through this research we have identified two statistically significant spatial scales characteristic of J. occidentalis on the woodland/steppe ecotone: (1) We observed inhibition between J. occidentalis plants at distances <15 m, resulting in a regular pattern, rather than clumped or random. This short-distance inhibition can be attributed to competition for water and other resources. Recruitment of young J. occidentalis occurs significantly more often in a direction away from older plants, maximizing the utilization of water and light resources, and perpetuating the spread of the species into previously juniper-free shrub-steppe. (2) J. occidentalis on the ecotone exhibits significant clustering within a 30–60 m radius. Bivariate point pattern analyses provide evidence that, within a distance of 50–70 m, there is a spatial dependence in tree size such that medium trees are more likely than small trees to be close to large trees. We attribute these phenomena to the fact that juniper seeds are commonly dispersed by berry-eating birds with small territories (0.3–1 ha). Beyond a distance of 50–70 m, juniper plants are randomly distributed, suggesting that additional long-range seed dispersal processes are at work. We further acknowledge the importance of including a reference to spatial scale when formulating hypotheses in statistical analysis of spatio-temporal point patterns.     

Modulation of cargo release from dense core granules by size and actin network

During regulated fusion of secretory granules with the plasma membrane, a fusion pore first opens and then dilates. The dilating pore allows cargo proteins from the dense core to be released into the extracellular space. Using real-time evanescent field fluorescence microscopy of live PC12 cells, it was determined how rapidly proteins of different sizes escape from single granules after fusion. Tissue plasminogen activator (tPA)-Venus is released 40-fold slower than the three times smaller neuropeptide Y [NPY-monomeric GFP (mGFP)]. An NPY bearing two mGFPs in tandem [NPY-(mGFP)₂] as an intermediate-sized fusion probe is released most slowly. Although, the time–course of release varies substantially for a given probe. Coexpression of β-actin, actin-related protein 3 or mAbp1 slowed the release of the two larger cargo molecules but did not affect release of NPY-mGFP or of the granule-membrane-bound probe Vamp-pHluorin. Additionally, high concentrations of cytochalasin D slowed release of the tPA-Venus. Together these results suggest that fusion pore dilation is not the only determinate of release time–course and that actin rearrangements similar to those mediating actin-mediated motility influences the time–course of release without directly interfering with the granule membrane to cell membrane connection.     

Research on WNN Greenhouse Temperature Prediction Method Based on GA

Temperature in agricultural production has a direct impact on the growth of crops. The emergence of greenhouses has improved the impact of the original unpredictable changes in temperature, but the temperature modeling of greenhouses is still the main direction at present. Neural network modeling relies on sufficient actual data to model greenhouses, but there is a widening gap in the application of different neural networks. This paper proposes a greenhouse temperature prediction model based on wavelet neural network with genetic algorithm (GA-WNN). With the simple network structure and the nonlinear adaptability of the wavelet basis function, wavelet neural network (WNN) improved model training speed and accuracy of prediction results compared with back propagation neural networks (BPNN), which was conducive to the prediction and control of short-term greenhouse temperature fluctuations. At the same time, the genetic algorithm (GA) was introduced to globally optimize the initial weights of the original model, which improved the insensitivity of the model to the initial weights and thresholds, and improved the training speed and stability of the model. Finally, simulation results for the greenhouse showed that the model training speed, prediction results accuracy and model stability of the GA-WNN in the greenhouse were improved in comparison to results obtained by the WNN and BPNN in the greenhouse.