Productivity and mineral cycling in an oak coppice forest 2. Annual net production of the forest

Annual net production was estimated in the secondary coppice forest near Tokyo, which was dominated by a deciduous oak,Quercus serrata Thunb. Lateral growth of stems and old branches was directly estimated by examining the annual rings for 35 shoots in a clear-cut quadrat of 10m×10m. Phytomasses of current organs were also weighed in the quadrat. Preharvest losses of current organs were determined by twelve 0.5 m² litter traps for fine litter and twelve 6 m² quadrats for woody litter. Branch production was also assessed indirectly by use of the stem-branch allometry and death of branches. The results of the indirect method were in sufficient agreement with the result of the direct one. Grazing loss of leaves from the canopy was estimated directly from the loss in leaf area and indirectly from the animal faeces caught by the litter traps. Net production of the canopy trees was 149 kg a⁻¹ year⁻¹, in which leaf production was 36.9 kg. Animals grazed about 14% of the leaf area by the end of the growing season. True consumption of leaves by animals was 7.6% of leaf production or 10% of leaf mass. Production of undergrowth, mainly a dwarf bamboo,Pleioblastus chino Makino, was 28 kg a⁻¹ year⁻¹, being 15% of the total stand production. Productivity of this forest was significantly higher than that of cool-temperate deciduous broadleaf forests.     

Molecular dipole effects on tuning electron transfer in a porphine–quinone complex: a DFT and TDDFT study

The effect of a strong electric field generated by molecular dipoles on the ground state electronic structure and the Q and B states as well as the lowest charge transfer (CT) excited state of porphine–2,5-dimethyl-1,4-benzoquinone (PQ) complex has been investigated theoretically. Density functional theory DFT and time-dependent DFT (TDDFT) with the BH&HLYP hybrid functional have been applied in these calculations. The molecular dipole effect was generated by imposing one or two helical homopeptides consisting of eight α-aminoisobutyric acid residues (Aib₈) close to the PQ complex. The molecular dipoles in a close proximity to the PQ complex expose it to an electric field of the order of magnitude of 10⁹ V/m. The presence of the ambient molecular dipoles affects mainly the energy of the lowest CT state and barely the energies of the Q and B states. The molecular dipoles affect the energies of the excited states in a similar way as an external electrostatic field. Hence, the electric field induced by the molecular dipoles of the helical peptides could be used analogously to the external electrostatic field to control electron transfer (ET) in the PQ complex.     

In vitro anticancer activity of loquat tea by inducing apoptosis in human leukemia cells

Fresh loquat leaves have been used as folk health herb in Asian countries for long time, although the evidence supporting their functions is still minimal. This study aimed to clarify the chemopreventive effect of loquat tea extract (LTE) by investigating the inhibition on proliferation, and underlying mechanisms in human promyelocytic leukemia cells (HL-60). LTE inhibited proliferation of HL-60 in a dose-dependent manner. Molecular data showed that the isolated fraction of LTE induced apoptosis of HL-60 as characterized by DNA fragmentation; activation of caspase-3, -8, and -9; and inactivation of poly(ADP)ribose polymerase. Moreover, LTE fraction increased the ratio of pro-apoptotic Bcl-2-associated X protein (Bax)/anti-apoptotic myeloid cell leukemia 1 (Mcl-1) that caused mitochondrial membrane potential loss and cytochrome c released to cytosol. Thus, our data indicate that LTE might induce apoptosis in HL-60 cells through a mitochondrial dysfunction pathway. These findings enhance our understanding for chemopreventive function of loquat tea.     

Stress-Induced Visceral Hypersensitivity in Maternally Separated Rats Can Be Reversed by Peripherally Restricted Histamine-1-Receptor Antagonists

Background

The histamine-1 receptor (H1R) antagonist ketotifen increased the threshold of discomfort in hypersensitive IBS patients. The use of peripherally restricted and more selective H1R antagonists may further improve treatment possibilities. We examined the use of fexofenadine and ebastine to reverse post-stress visceral hypersensitivity in maternally separated rats.

Methods

The visceromotor response to colonic distension was assessed in adult maternally separated and nonhandled rats pre- and 24 hours post water avoidance. Subsequently rats were treated with vehicle alone or different dosages of fexofenadine (1.8 and 18 mg/kg) or ebastine (0.1 and 1.0 mg/kg) and re-evaluated. Colonic tissue was collected to assess relative RMCP-2 and occludin expression levels by Western blot and histamine-1 receptor by RT-qPCR. β-hexosaminidase release by RBL-2H3 cells was used to establish possible mast cell stabilizing properties of the antagonists.

Key results

Water avoidance only induced enhanced response to distension in maternally separated rats. This response was reversed by 1.8 and 18 mg/kg fexofenadine. Reversal was also obtained by 1.0 but not 0.1 mg/kg ebastine. RMCP-2 expression levels were comparable in these two ebastine treatment groups but occludin was significantly higher in 1.0 mg/kg treated rats. There were no differences in histamine-1 receptor expression between nonhandled and maternally separated rats. Fexofenadine but not ebastine showed mast cell stabilizing quality.

Conclusions

Our results indicate that the peripherally restricted 2^nd generation H1-receptor antagonists fexofenadine and ebastine are capable of reversing post stress visceral hypersensitivity in rat. These data justify future IBS patient trials with these well tolerated compounds.     

Transcriptional suppression of nephrin in podocytes by macrophages: roles of inflammatory cytokines and involvement of the PI3K/Akt pathway

Expression of nephrin, a crucial component of the glomerular slit diaphragm, is downregulated in patients with proteinuric glomerular diseases. Using conditionally immortalized reporter podocytes, we found that bystander macrophages as well as macrophage-derived cytokines IL-1beta and TNF-alpha markedly suppressed activity of the nephrin gene promoter in podocytes. The cytokine-initiated repression was reversible, observed on both basal and inducible expression, independent of Wilms' tumor suppressor WT1, and caused in part via activation of the phosphatidylinositol-3-kinase/Akt pathway. These results indicated a novel mechanism by which activated macrophages participate in the induction of proteinuria in glomerular diseases.     

Regulation of PSII function in Cyanothece sp. ATCC 51142 during a light–dark cycle

Photosynthesis Research - Cyanobacteria, as well as green algae and higher plants, have highly conserved photosynthetic machinery. Cyanothece sp. ATCC 51142 is a unicellular, aerobic, diazotrophic...     

Anti-fungal sesquiterpenoid from the root exudate of Solanum abutiloides

The Solanum abutiloides plant is highly resistant to soil-borne pathogens such as Fusarium oxysporum f. sp. melongenae, Verticillium dahliae, and Ralstonia solanacearum. This species is utilized as a mating source of resistant cultivars and is also used as a rootstock. The root exudate of Solanum abutiloides was extracted from a soil system composed of charcoal and vermiculite. Anti-fungal activity was found in the extract, and an active ingredient was isolated. The chemical structure of the active compound was determined to be 3-beta-acetoxysolavetivone, a new sesquiterpenoid. The anti-fungal activity of 3-beta-acetoxysolavetivone examined by the inhibition of spore germination of Fusarium oxysporum was close to that of lubimin, and higher than that of solavetivone.     

Remodeling of resistance arteries in organoid culture is modulated by pressure and pressure pulsation and depends on vasomotion

The hypothesis was tested that pressure and pressure pulsation modulate vascular remodeling. Arterioles ( approximately 200 microm lumen diameter) were dissected from rat cremaster muscle and studied in organoid culture. In the first series, arterioles were kept at a stable pressure level of either 50 or 100 mmHg for 3 days. Both groups showed a progressive increase in myogenic tone during the experiment. Arterioles kept at 50 mmHg showed larger endothelium-dependent dilation, compared with vessels kept at 100 mmHg on day 3. Remodeling, as indicated by the reduction in maximally dilated diameter at 100 mmHg, was larger in arterioles kept at 50 mmHg compared with 100 mmHg: 34 +/- 4.5 versus 10 +/- 4.8 microm (P < 0.05). In the second series, arterioles were subjected to a stable pressure of 60 mmHg or oscillating pressure of 60 +/- 10 mmHg (1.5 Hz) for 4 days. Pressure pulsation induced partial dilation and was associated with less remodeling: 34 +/- 4.0 versus 19 +/- 4.5 microm (P < 0.01) for stable pressure versus oscillating pressure. Vasomotion was frequently observed in all groups, and inward remodeling was larger in vessels with vasomotion: 30 +/- 2.5 microm compared with vessels that did not exhibit vasomotion: 8.0 +/- 5.0 microm (P < 0.01). In conclusion, these results indicate that remodeling is not enhanced by high pressure. Pressure pulsation causes partial dilation and reduces inward remodeling. The appearance of vasomotion is associated with enhanced inward remodeling.     

The carboxy-terminal pleckstrin homology domain of ROCK interacts with filamin-A

The small GTPase Rho and its effector ROCK/Rho-kinase regulate actin cytoskeletal reorganization through phosphorylation of the regulatory light chain of myosin II. We previously reported that ROCK co-purified with the actin-binding protein filamin-A from HeLa cells. Here, we show that the pleckstrin homology (PH) domain of ROCK, but not the kinase or coiled-coil domain, interacts with filamin-A. We also determined that the PH domain of ROCK binds to the carboxy-terminal region of filamin-A containing the last 24th repeat. ROCK co-localized with filamin-A at the protrusive cell membranes of HeLa cells.