The effects of creatine monohydrate loading on anaerobic performance and one-repetition maximum strength

The purpose of this study was to examine the effects of 7 days of supplementation with 20 g·d?1 of creatine monohydrate (CM) on mean power (MP) and peak power (PP) from the Wingate anaerobic test (WAnT), body weight (BW), 1-repetition maximum (1RM) bilateral leg extension (LE) strength, and 1RM bench press (BP) strength. This study used a randomized, double-blind, placebo-controlled design. Twenty-two men (mean ± SD: age = 22.1 ± 2.0 years; height = 178.0 ± 5.8 cm; body weight [BW] = 77.6 ± 7.6 kg) were randomly assigned to either a supplement (SUPP; n = 10) or placebo (PLAC; n = 12) group. The SUPP group ingested 20 g·d?1 of CM powder for 7 days, whereas the PLAC ingested 20 g·d?1 of maltodextrin powder. Measurements for the PLAC and SUPP groups included BW, PP, and MP from two 30-second WAnTs (separated by 7 minutes), and 1RM strength for LE and BP. Testing was conducted before (PRE) and after (POST) 7 days of ingesting either the supplement or placebo. The results of this study indicated that there was a significant (p ≤ 0.05) increase from PRE to POST testing in MP for the SUPP group (5.4%) but not for the PLAC group (-0.3%). There were no between-group differences, however, for 1RM LE and 1RM BP strength. Furthermore, there were no changes in PP or BW for either group. The findings of this study indicated that loading with 20 g·d?1 of CM for 7 days increased MP (5.4% increase) from the WAnT, but it had no effect on strength (1RM LE and 1RM BP), PP, or BW.     

Dissociated neural processing for decisions in managers and non-managers

Functional neuroimaging studies of decision-making so far mainly focused on decisions under uncertainty or negotiation with other persons. Dual process theory assumes that, in such situations, decision making relies on either a rapid intuitive, automated or a slower rational processing system. However, it still remains elusive how personality factors or professional requirements might modulate the decision process and the underlying neural mechanisms. Since decision making is a key task of managers, we hypothesized that managers, facing higher pressure for frequent and rapid decisions than non-managers, prefer the heuristic, automated decision strategy in contrast to non-managers. Such different strategies may, in turn, rely on different neural systems. We tested managers and non-managers in a functional magnetic resonance imaging study using a forced-choice paradigm on word-pairs. Managers showed subcortical activation in the head of the caudate nucleus, and reduced hemodynamic response within the cortex. In contrast, non-managers revealed the opposite pattern. With the head of the caudate nucleus being an initiating component for process automation, these results supported the initial hypothesis, hinting at automation during decisions in managers. More generally, the findings reveal how different professional requirements might modulate cognitive decision processing.     

Infection of myeloid dendritic cells with Listeria monocytogenes leads to the suppression of T cell function by multiple inhibitory mechanisms

Myeloid dendritic cells (DC) and macrophages play an important role in pathogen sensing and antimicrobial defense. In this study we provide evidence that myeloid DC respond to infection with Listeria monocytogenes with simultaneous induction of multiple stimulatory and inhibitory molecules. However, the overall impact of infected DC during T cell encounter results in suppression of T cell activation, indicating that inhibitory pathways functionally predominate. Inhibitory activity of infected DC is effected mainly by IL-10 and cyclooxygenase 2-mediated mechanisms, with soluble CD25 acting as an IL-2 scavenger as well as by the products of tryptophan catabolism. These inhibitory pathways are strictly TNF-dependent. In addition to direct infection, DC bearing this regulatory phenotype can be induced in vitro by a combination of signals including TNF, TLR2, and prostaglandin receptor ligation and by supernatants derived from the infected cells. Both infection-associated DC and other in vitro-induced regulatory DC are characterized by increased resistance to infection and enhanced bactericidal activity. Furthermore, myeloid DC expressing multiple regulatory molecules are identified in vivo in granuloma during listeriosis and tuberculosis. Based on the in vivo findings and the study of in vitro models, we propose that in granulomatous infections regulatory DC may possess dual function evolved to protect the host from disseminating infection via inhibition of granuloma destruction by T cells and control of pathogen spreading.     

Photosynthetic limitations in leaves of young Brazilian Green Dwarf coconut (Cocos nucifera L. ‘nana’) palm under well-watered conditions or recovering from drought stress

Young plants of two Brazilian Green Dwarf coconut ecotypes from contrasting regions in relation to climate (UGD, from a hot and humid climate and JGD, from a hot and dry climate) were submitted to three consecutive drying/recovery cycles, under greenhouse conditions to determine the photosynthetic limitations encountered during the recovery phase of water deficiency. Three hypotheses were tested: (1) non-stomatal factors contribute to the incomplete recovery of net photosynthesis rate (A), (2) photochemical impairment is an important component of the non-stomatal limitations to A and (3) the two coconut ecotypes respond differently to the drought recovery. In each drying/recovery cycle, irrigation was suppressed until A reached zero. Then the plants were rewatered and the recovery was accompanied for 8 days. After 4 days of rewatering, CO₂ and light response curve parameters were used to discriminate the stomatal and non-stomatal factors contributing to the incomplete recovery of A. Upon rewatering for 4 days, the pre-dawn leaf water potential of the stressed plants increased from ?1.20 to ?0.15 MPa on average. Only small differences were detected in the intercellular to atmospheric CO₂ concentration ratio but A did not recover completely to the control values. In both ecotypes, light and CO₂-saturated A, carboxylation efficiency, maximum quantum yield of PSII and maximum electron transport rate were significantly lower in stressed plants in comparison with the well-watered ones. Relative stomatal limitation (L_S) ranged from 16 to 20% without significant differences between treatments and between ecotypes. The relative mesophyll limitation (L_m) was significantly higher in JGD in cycle 1 but this changed after repeated drought stress, decreasing to values significantly lower than those in UGD in the other two cycles. The results showed that after 4 days of rewatering stressed plant stomatal limitations were comparable to that of well-watered control plants (～20%). However A did not recover completely after drought stress due to non-stomatal factors. Important differences between the ecotypes were identified. The ecotype JGD presented smaller L_m, faster recovery of the apparent quantum efficiency of CO₂ assimilation, adjustment of some carbon balance components and signs of photosynthetic capacity acclimation after repeated drying/recovery cycles.     

RIP2 regulates growth and differentiation of normal myoblasts and of rhabdomyosarcoma cells

RIP2 is an important regulator of myoblast proliferation and differentiation. We have previously demonstrated that in the myoblast cell line C2C12 and in primary myoblasts, downregulation of rip2 gene expression is a prerequisite for differentiation. To further study the role of rip genes in myogenesis, we compared expression patterns of rip1–4 in two myoblast cell lines, C2C12 and C2F3, after the induction of differentiation. These two cell lines are derived from the same clonal origin, but differ with respect to their differentiation behaviour: specifically, the differentiation process is slower and more incomplete in C2F3 cells. When analyzing cells up to 4 days after the induction of differentiation, we found no downregulation of rip2 gene expression in C2F3 cells, which might be linked to the low differentiation potential of these cells. In addition, in contrast to C2C12 cells, the rip3 gene was not expressed in C2F3 cells. To further study the role of rip genes in the regulation of myoblast growth and differentiation, we analyzed expression patterns of rip1–4 in rhabdomyosarcoma cell lines. We found that in these cells, rip2 expression was not downregulated after the induction of differentiation. Furthermore, in contrast to normal myoblasts, they did not express the rip3 and rip4 genes. Thus, we focused on the functional role of RIP2 in rhabdomyosarcoma cells. Inhibition of rip2 gene expression in C2C12 and in rhabdomyosarcoma cells using specific siRNAs led to decreased proliferation and promoted the differentiation process of these cells. These data indicate that differential expression of rip genes can be associated with abnormal growth and differentiation behaviour of skeletal myoblasts.     

The RGD integrin binding site in human L1-CAM is important for nuclear signaling

L1 cell adhesion molecule (L1-CAM) is a transmembrane cell adhesion molecule initially defined as a promigratory molecule in the developing nervous system. L1 is also overexpressed in a variety of human carcinomas and is associated with bad prognosis. In carcinoma cell lines L1 augments cell motility and metastasis, tumor growth in nude mice and induces expression of L1-dependent genes. It is not known whether L1-signaling requires ligand binding. The RGD motif in the sixth Ig domain of L1 is a binding site for integrins. In the present study we analyzed the role of RGDs in L1-signaling using site-directed mutagenesis combined with antibody blocking studies. We observed that L1-RGE expressing HEK293 cells showed reduced cell–cell binding, cell motility, invasiveness and tumor growth in NOD/SCID mice. The RGE-mutation impaired L1-dependent gene regulation and antibodies to αvβ5 integrin had similar effects. Mutant L1 was unable to translocate to the nucleus. Our findings highlight the importance of the RGD site in L1 for human tumors and suggest that nuclear signaling of L1 is dependent on integrins.     

Esterase Autodisplay: Enzyme Engineering and Whole-Cell Activity Determination in Microplates with pH Sensors

Among the GDSL family of serine esterases/lipases is a group of bacterial enzymes that posses C-terminal extensions involved in outer membrane anchoring or translocation. ApeE from Salmonella enterica serovar Typhimurium, a member of this group, has been expressed in Escherichia coli and was resistant to protease digestion when the protease was added to whole cells, indicating a periplasmic localization. The five consensus blocks conserved within all GDSL esterases were identified in ApeE by multiple sequence alignment and separated from the C-terminal extension. The DNA sequence spanning the four invariant residues Ser, Gly, Asn, and His, and hence representing the catalytic domains of ApeE, was amplified by PCR and fused in frame to the transport domains of the autodisplay system. The resulting artificial esterase, called EsjA, was overexpressed in the cell envelope of E. coli and was shown to be active by the use of α-naphthyl acetate (α-NA) as a substrate in an in-gel activity stain after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Surface exposure of EsjA was indicated by its accessibility to protease added to whole cells. The esterase activity of whole cells displaying EsjA was determined by a pH agar assay and by the use of microplates with integrated pH-dependent optical sensors. α-NA, α-naphthyl butyrate, and α-naphthyl caproate were used as substrates, and it turned out that the substrate preferences of artificial EsjA were altered in comparison to original ApeE. Our results indicate that autodisplay of esterase in combination with pH sensor microplates can provide a new platform technology for the screening of tailor-made hydrolase activities.     

Comparative cytomorphology of pituitary adenomas and oligodendrogliomas in intraoperative crush preparations.

Minute fresh tissue fragments from 20 pituitary adenomas and 18 oligodendrogliomas were crushed between two glass slides and stained with hematoxylin and eosin for cytologic examination. These two tumor types displayed distinctive cytologic features that may permit their correct identification. Pituitary adenomas were characterized by single and clustered tumor cells with monomorphic, round or vesicular nuclei that were commonly denuded of cytoplasm. Rare well-preserved tumor cells showed well- or ill-defined, variable and granular cytoplasm. Oligodendrogliomas showed cells with monomorphic or slightly pleomorphic nuclei and scant, fibrillary, wispy cytoplasm, commonly arranged in clusters or around circular and empty spaces.     

Impacts of coral bleaching on pH and oxygen gradients across the coral concentration boundary layer: a microsensor study

Coral Reefs - Reef-building corals are surrounded by complex microenvironments (i.e. concentration boundary layers) that partially isolate them from the ambient seawater. Although the presence of...     

Ammonium, nitrate, and total nitrogen in the soil water of feedlot and field soil profiles

A level feedlot, located in an area consisting of Wann silt loam changing with depth to sand, appears to contribute no more NO₃^- nitrogen, NH₄⁺ nitrogen, and total nitrogen to the shallow water table beneath it than an adjacent cropped field. Soil water samples collected at 46, 76, and 107 cm beneath the feedlot surface generally showed NO₃^- nitrogen concentrations of less than 1 μg/ml. During the summer months, soil water NO₃^- nitrogen increased at the 15-cm depth, indicating that nitrification took place at the feedlot surface. However, the low soil water NO₃^- nitrogen values below 15 cm indicate that denitrification takes place beneath the surface.