Salinity-dependent copy number increase of a marine cyanobacterial endogenous plasmid

Listeria monocytogenes possessed glucose oxidase and NADH oxidase activities in whole cells and lysed protoplasts respectively. The NADH oxidase activity sedimented with the membrane fraction and was inhibited by the respiratory inhibitors rotenone, 2-heptyl-4-hydroxy-quinoline-N-oxide and cyanide, suggesting the presence of a membrane associated respiratory chain.     

Some experiments and analysis of a predator-prey model: Interaction between Colpidium campylum and Alcaligenes faecalis in continuous and mixed culture

Following previous work in which a mass and monoxenous culture of Vorticella microstoma had been successfully established (Water Res., 7 , 615 lpar;1973) another species of Ciliata, Colpidium campylum was subjected to continuous cultivation using Alcaligenes faecalis as the sole bacterial food and asparagine as the limiting substrate. This work was primarily undertaken to reveal the interaction and biological oscillation between these two types of organisms which simulate theecological behavior of activated sludge. The fact that the bacteria tended to flocculate and/ or deflocculate depending on the protozoan populastion density was incorporated into the rate equations to account for the oscillation in individual population density of the predator-prey system The mathematical approach presented earlier by canal and other workers forbiological oscillation used a homogeneously of the bacterial food wasoverelooked in the earlier publication.     

Changes in fatigue,autonomic functions,and blood biomarkers due to sitting isometric yoga in patients with chronic fatigue syndrome

Background

In a previous randomized controlled trial, we found that sitting isometric yoga improves fatigue in patients with chronic fatigue syndrome (CFS) who are resistant to conventional therapy. The aim of this study was to investigate possible mechanisms behind this finding, focusing on the short-term fatigue-relieving effect, by comparing autonomic nervous function and blood biomarkers before and after a session of isometric yoga.

Methods

Fifteen patients with CFS who remained symptomatic despite at least 6 months of conventional therapy practiced sitting isometric yoga (biweekly 20 min practice with a yoga instructor and daily home practice) for eight weeks. Acute effects of sitting isometric yoga on fatigue, autonomic function, and blood biomarkers were investigated after the final session with an instructor. The effect of a single session of sitting isometric yoga on fatigue was assessed by the Profile of Mood Status (POMS) questionnaire immediately before and after the session. Autonomic nervous function (heart rate (HR) variability) and blood biomarkers (cortisol, DHEA-S, TNF-α, IL-6, IFN-γ, IFN-α, prolactin, carnitine, TGF-β1, BDNF, MHPG, and HVA) were compared before and after the session.

Results

Sitting isometric yoga significantly reduced the POMS fatigue score (p?<?0.01) and increased the vigor score (p?<?0.01). It also reduced HR (p?<?0.05) and increased the high frequency power (p?<?0.05) of HR variability. Sitting isometric yoga increased serum levels of DHEA-S (p?<?0.05), reduced levels of cortisol (p?<?0.05) and TNF-α (p?<?0.05), and had a tendency to reduce serum levels of prolactin (p?<?0.1). Decreases in fatigue scores correlated with changes in plasma levels of TGF-β1 and BDNF. In contrast, increased vigor positively correlated with HVA.

Conclusions

A single session of sitting isometric yoga reduced fatigue and increased vigor in patients with CFS. Yoga also increased vagal nerve function and changed blood biomarkers in a pattern that suggested anti-stress and anti-inflammatory effects. These changes appear to be related to the short-term fatigue-relieving effect of sitting isometric yoga in patients with CFS. Furthermore, dopaminergic nervous system activation might account for sitting isometric yoga-induced increases in energy in this patient population.

Trial registration

University Hospital Medical Information Network (UMIN CTR) UMIN000009646. Registered Dec 27, 2012.

     

Phosphofructokinase of Solanum tuberosum tuber

Potato tuber phosphofructokinase was purified 19·.6-fold by a combination of ethanol fractionation and DEAE-cellulose column chromatography. The enzyme was very unstable; its pH optimum was 8·0. K_m for fructose-6-phosphate, ATP and Mg²⁺ was 2·1 × 10^?4 M, 4·5 × 10^?5 M and 4·0 × 10^?4 M respectively. ITP, GTP, UTP and CTP can act as phosphate donors, but are less active than ATP. Inhibition of enzyme activity by high levels of ATP was reversed by increasing the concentration of fructose-6-phosphate; the affinity of enzyme for fructose-6-phosphate decreased with increasing concentration of ATP. 5′-AMP, 3′,5′-AMP, 3′-AMP, deoxy AMP, UMP, IMP, CMP, GMP, ADP, CDP, GDP and UDP did not reverse the inhibition of enzyme by ATP. ADP, phosphoenolpyruvate and citrate inhibited phosphofructokinase activity but Pi did not affect it. Phosphofructokinase was not reactivated reversibly by mild change of pH and addition of effectors.     

Calmodulin‐like skin protein protects against spatial learning impairment in a mouse model of Alzheimer disease

Humanin and calmodulin‐like skin protein (CLSP) inhibits Alzheimer disease (AD)‐related neuronal cell death via the heterotrimeric humanin receptor in vitro . It has been suggested that CLSP is a central agonist of the heterotrimeric humanin receptor in vivo . To investigate the role of CLSP in the AD pathogenesis in vivo , we generated mouse CLSP‐1 transgenic mice, crossed them with the APPswe/PSEN1dE9 mice, a model mouse of AD, and examined the effect of CLSP over‐expression on the pathological phenotype of the AD mouse model. We found that over‐expression of the mouse CLSP‐1 gene attenuated spatial learning impairment, the loss of a presynaptic marker synaptophysin, and the inactivation of STAT3 in the APPswe/PSEN1dE9 mice. On the other hand, CLSP over‐expression did not affect levels of Aβ, soluble Aβ oligomers, or gliosis. These results suggest that the CLSP‐mediated attenuation of memory impairment and synaptic loss occurs in an Aβ‐independent manner. The results of this study may serve as a hint to the better understanding of the AD pathogenesis and the development of AD therapy.

     

Structural analysis of the phototactic transducer protein HtrII linker region from Natronomonas pharaonis

Halobacterial pharaonis phoborhodopsin [ppR, also called Natronomonas pharaonis sensory rhodopsin II (NpSRII)] is a phototaxis protein which transmits a light signal to the cytoplasm through its transducer protein (pHtrII). pHtrII, a two-transmembrane protein that interacts with ppR, belongs to the group of methyl-accepting chemotaxis proteins (MCPs). Several mutation studies have indicated that the linker region connecting the transmembrane and methylation regions is necessary for signal transduction. However, the three-dimensional (3D) structure of an MCP linker region has yet to be reported, and hence, details concerning the signal transduction mechanism remain unknown. Here the structure of the pHtrII linker region was investigated biochemically and biophysically. Following limited proteolysis, only one trypsin resistant fragment in the pHtrII linker region was identified. This fragment forms a homodimer with a Kd value of 115 microM. The 3D structure of this fragment was determined by solution NMR, and only one alpha-helix was found between two HAMP domains of the linker region. This alpha-helix was significantly stabilized within transmembrane protein pHtrII as revealed by CW-EPR. The presence of Af1503 HAMP domain-like structures in the linker region was supported by CD, NMR, and ELDOR data. The alpha-helix determined here presumably works as a mechanical joint between two HAMP domains in the linker region to transfer the photoactivated conformational change downstream.     

Phosphate metabolism during diel vertical migration in the raphidophycean alga, Chattonella antiqua

The ecological advantage of diel vertical migration on the nutrition and accumulation of Chattonella antiqua, which is one of the dominant red-tide forming phytoplankton species in the Seto Inland Sea of Japan, was examined using a large axenic culture tank, in which vertical stratification of salinity, temperature and nutrients was maintained, analogous to natural conditions observed when red tides occur. C. antiqua was capable of migrating through very sharp salinity and temperature gradients. At night the species migrated to the deep nutrient-rich water and assimilated nutrients. During the daytime it migrated to the nutrient-depleted surface water and used the accumulated nutrients for photosynthesis. Nitrogen uptake was synchronized with phosphate uptake. ³¹P-NMR spectroscopy during the migration experiment revealed that C. antiqua has the capability of nocturnal phosphate uptake in the deep nutrient-rich water, but no capability of synthesizing polyphosphate, which was considered to be the intracellular phosphate pool. These findings were compared with those reported for another raphidophycean, Heterosigma akashiwo. Although both species carry out vertical migration and nocturnal nutrient uptake, only H. akashiwo has the capability of making an intracellular polyphosphate pool. This revised version was published online in July 2006 with corrections to the Cover Date.     

Human umbilical cord-derived cells can often serve as feeder cells to maintain primate embryonic stem cells in a state capable of producing hematopoietic cells

Clinical application of human embryonic stem (ES) cells will require the establishment of methods for their culture, either in the presence or absence of human-derived feeder cells. We have tested the ability of non-immortalized cultured cells derived from human umbilical cord (HUC cells) to support ES cell culture. A primate ES cell line that had been established and maintained with mouse embryonic fibroblasts was cultured on HUC cells for >3 months (HUC-maintained ES cells). These cells retained their expression of alkaline phosphatase, SSEA-4, Oct-3/4, and to a lesser extent Nanog, but did not express Rex-1. Nevertheless, HUC-maintained ES cells could produce ectoderm-, mesoderm- and endoderm-derived cells in teratomata that they formed in immunodeficient mice. We show that HUC-maintained ES cells could give rise to hematopoietic cells, although this ability of HUC cells varied among HUC cell populations derived from different neonates. HUC cells are promising as human material with which to maintain ES cells in a state that retains their ability to produce mature cells, including hematopoietic cells.