Expression patterns of genes encoding carbohydrate-metabolizing enzymes and their relationship to grain filling in rice (Oryza sativa L.): comparison of caryopses located at different positions in a panicle

In rice, caryopses located at the base of the panicle have a lower growth rate than those at the tip of the panicle. The former and latter types of caryopses are called inferior and superior caryopses, respectively. Taking the different growth rate into consideration, sugar status and the expression of genes encoding carbohydrate-metabolizing enzymes in inferior caryopses were compared with those in superior caryopses. During the first 5 d after flowering, superior caryopses elongated rapidly, but inferior caryopses did not. At this phase, inferior caryopses had a low ratio of hexose to sucrose, high activity of acid invertase and the absence of the expression of the genes encoding the above enzymes except for two isoforms of cell wall invertase, OsCIN4 and INV1, in comparison with superior caryopses. At the start of caryopsis elongation in both superior and inferior caryopses, the hexose/sucrose ratio increased accompanied by gene expression of vacuolar invertase (INV3), sucrose synthase (RSus1) and ADP-glucose pyrophosphorylase (AGP-L2: D50317). Furthermore, the genes related to endospermal starch accumulation were expressed highly with the decrease in the hexose/sucrose ratio after its peak. Based on the comparison of superior and inferior caryopses, the possible mechanism of grain filling in rice is discussed.     

Examination of bovine lactoferrin binding to bifidobacteria

In the present study, lactoferrin binding to bifidobacteria and detection of lactoferrin-binding protein in membrane fractions of several bifidobacteria have been demonstrated. This is the first report showing the binding of bovine lactoferrin to four Bifidobacterium spp. (B. infantis, B. breve, B. bifidum, B. longum) incubated with biotinylated lactoferrin and fluorescein conjugated-avidin and observed under an inverted confocal laser scanning microscope. Fluorescence staining showed lactoferrin binding at the pole of the bacterial cells. A lactoferrin-binding protein with a molecular weight of approximately 67 kDa was also detected in the membrane fraction of Bifidobacterium spp. by far western blotting technique using biotinylated lactoferrin and horseradish peroxidase-conjugated streptavidin. Based on the results of this and previously reported studies, we suggest that binding of lactoferrin to Bifidobacterium longum is strain-dependent.     

Bovine lactoferrin region responsible for binding to bifidobacterial cell surface proteins

Bovine lactoferrin promotes bifidobacterial growth. Its binding to bifidobacteria is thought to be responsible for such action. After separating the bovine lactoferrin half molecule and extraction of surface proteins from bifidobacteria, binding profiles were observed by immunoblotting. No binding appeared when lactoferrin C-lobe was reacted with the cell surface proteins on a polyvinylidene difluoride membrane. Conversely, a 50-kDa band appeared when the surface proteins were reacted with either intact or nicked bovine lactoferrin. This result strongly suggests that the binding region could be lactoferrin N-lobe. Interestingly, despite the absence of binding, C-lobe enhanced bifidobacterial growth.     

Analysis by {delta}13C Measurement on Mechanism of Cultivar Difference in Leaf Photosynthesis of Rice (Oryza sativa L.)

Our previous paper showed that cultivar difference of flag leafphotosynthesis (LPS) in rice (Oryza sativa L.) was attributedto the difference in mesophyll resistance (r_m). In this paper,we tried to divide r_m into CO₂ transfer resistance (r_m) andCO₂ fixation resistance (r_c) for further analysis of r_m by meansof     

Inhibition of insulin-like growth factor-1 (IGF-1) expression by prolonged transforming growth factor-β1 (TGF-β1) administration suppresses osteoblast differentiation

TGF-β1 can regulate osteoblast differentiation not only positively but also negatively. However, the mechanisms of negative regulation are not well understood. We previously established the reproducible model for studying the suppression of osteoblast differentiation by repeated or high dose treatment with TGF-β1, although single low dose TGF-β1 strongly induced osteoblast differentiation. The mRNA expression and protein level of insulin-like growth factor-1 (IGF-1) were remarkably decreased by repeated TGF-β1 administration in human periodontal ligament cells, human mesenchymal stem cells, and murine preosteoblast MC3T3-E1 cells. Repeated TGF-β1 administration subsequently decreased alkaline phosphatase (ALP) activity and mRNA expression of osteoblast differentiation marker genes, such as RUNX2, ALP, and bone sialoprotein (BSP). Additionally, repeated administration significantly reduced the downstream signaling pathway of IGF-1, such as Akt phosphorylation in these cells. Surprisingly, exogenous and overexpressed IGF-1 recovered ALP activity and mRNA expression of osteoblast differentiation marker genes even with repeated TGF-β1 administration. These facts indicate that the key mechanism of inhibition of osteoblast differentiation induced by repeated TGF-β1 treatment is simply due to the down-regulation of IGF-1 expression. Inhibition of IGF-1 signaling using small interfering RNA (siRNA) against insulin receptor substrate-1 (IRS-1) suppressed mRNA expression of RUNX2, ALP, BSP, and IGF-1 even with single TGF-β1 administration. This study showed that persistence of TGF-β1 inhibited osteoblast differentiation via suppression of IGF-1 expression and subsequent down-regulation of the PI3K/Akt pathway. We think this fact could open the way to use IGF-1 as a treatment tool for bone regeneration in prolonged inflammatory disease.     

The response of forest floor vegetation and tree regeneration to deer exclusion and disturbance in a riparian deciduous forest,central Japan

The response of forest floor vegetation and regeneration of major treespecies to deer exclusion in a riparian forest were studied for 3 years withtheinteractive effects of natural disturbances. At the start of this study, deerdensity had quickly increased to a fairly high level (29–31 individualskm^–2) during the last decade and had severely reduced theamount of forest floor vegetation in the study area. Dwarf bamboos, which weredominant before, had almost diminished from the forest floor. During the studyperiod, aboveground biomass increased steadily but species diversity did notchange much in the exclosures. Outside the exclosures, the seedlings of alltreespecies were damaged greatly by deer browsing, especially the taller ones. Deerbrowsing had little effect on the emergence of tree seedlings, but deertrampling might have accelerated emergence indirectly by disturbing the soilsurface for some species. Differences in plant responses were also observed fordeer browsing and the presence of dwarf bamboo that strongly inhibits therecruitment of tree seedlings. The nine major species were classified intothreegroups according to the response of seedlings to deer browsing and disturbance.Group 1 consists of the species whose seedling survival is affected bybrowsing,but seldom by disturbances (Phellodendron amurense,Kalopanax pictus, Quercus crispulaandMalus toringo). Groups 2 and 3 consist of species adaptedto tree-fall disturbance (Betula spp.) and ripariandisturbance (Alnus hirsuta var.sibirica, Ulmus davidiana var.japonica, Populus maximowiczii andSalix sachalinensis), respectively, and seedling survivalof these two groups is principally affected by light conditions. The effect ofdeer browsing on seedling survival and growth was greater for Group 2 than forGroup 3.     

A randomized trial of chemoimmunotherapy of acute nonlymphocytic leukemia in adults using a protein-bound polysaccharide preparation

Summary The effect of immunotherapy with a protein-bound polysaccharide preparation termed PSK on remission duration and survival of adults with acute nonlymphocytic leukemia (ANLL) was studied in a prospective randomized cooperative trial. After having achieved complete remission and receiving a consolidation therapy, 73 patients were randomized either to maintenance chemotherapy or to maintenance chemotherapy plus immunotherapy with PSK. Ultimately 36 patients in the chemotherapy group and 31 in the chemoimmunotherapy group were evaluable. Six months after the last entry, immunotherapy with PSK showed a borderline beneficial effect on remission duration (P=0.089) and on duration of survival (P=0.062). When the data were analyzed 12, 18, and 24 months after the last entry there were no significant differences in duration of remission and survival between the two groups. However, analysis of the data of patients who had maintained complete remission for more than 270 days revealed that immunotherapy had a suggestive beneficial effect (P=0.105), prolonging the 50% remission period by 418 days (885 vs 467 days). Thus, immunotherapy with PSK seems to be active in the treatment of adult ANLL when used for maintenance therapy in combination with chemotherapy, especially in patients with a good prognosis.     

Genetic Characterization of pepP, Which Encodes an Aminopeptidase P Whose Deficiency Does Not Affect Lactococcus lactis Growth in Milk, Unlike Deficiency of the X-Prolyl Dipeptidyl Aminopeptidase

We sequenced the pepP gene of Lactococcus lactis, which encodes an aminopeptidase P (PepP), and demonstrated that the X-prolyl dipeptidyl aminopeptidase PepX plays a more important role than PepP in nitrogen nutrition. PepP shares homology with methionine aminopeptidases and could play a role in the maturation of nascent proteins.