Predicting Rice Lodging Risk from the Distribution of Available Nitrogen in Soil Using UAS Images in a Paddy Field.

Rice lodging causes a loss of yield and leads to lower-quality rice. In Japan, Koshihikari is the most popular rice variety, and it has been widely cultivated for many years despite its susceptibility to lodging. Reducing basal fertilizer is recommended when the available nitrogen in soil (SAN) exceeds the optimum level (80-200 mg N kg-1). However, many commercial farmers prefer to simultaneously apply one-shot basal fertilizer at transplant time. This study investigated the relationship between the rice lodging and SAN content by assessing their spatial distributions from unmanned aircraft system (UAS) images in a Koshihikari paddy field where one-shot basal fertilizer was applied. We analyzed the severity of lodging using the canopy height model and spatially clarified a heavily lodged area and a non-lodged area. For the SAN assessment, we selected green and red band pixel digital numbers from multispectral images and developed a SAN estimating equation by regression analysis. The estimated SAN values were rasterized and compiled into a 1 m mesh to create a soil fertility map. The heavily lodged area roughly coincided with the higher SAN area. A negative correlation was observed between the rice inclination angle and the estimated SAN, and rice lodging occurred even within the optimum SAN level. These results show that the amount of one-shot basal fertilizer applied to Koshihikari should be reduced when absorbable nitrogen (SAN + fertilizer nitrogen) exceeds 200 mg N kg-1.

Modified oligodeoxynucleotide primers for reverse-transcription of target RNAs that can discriminate among length variants at the 3'-terminus.

To discriminate among miRNA length variants, we synthesized conformationally restricted or unrestricted oligonucleotides containing a cyclohexyl phosphate residue. These oligonucleotides formed duplexes with length-matched complementary miRNAs more tightly than with length variants. The use of one of these modified oligodeoxynucleotides as a reverse transcription primer enabled a novel RT-PCR that can discriminate among miRNA length variants.

Synthesis and hybridization properties of 2'-O-methylated oligoribonucleotides incorporating 2'-O-naphthyluridines.

2'-O-(1-Naphthyl)uridine and 2'-O-(2-naphthyl)uridine were synthesized by a microwave-mediated reaction of 2,2'-anhydrouridine with naphthols. Using the 3'-phosphoramidite building blocks, these 2'-O-aryluridine derivatives were incorporated into 2'-O-methylated oligoribonucleotides. Incorporation of five 2'-O-(2-naphthyl)uridines into a 2'-O-methylated RNA sense strand significantly increased the thermostability of the duplex with a 2'-O-methylated RNA antisense strand. Circular dichroism spectroscopy and molecular dynamic simulation of the duplexes formed between the modified RNAs and 2'-O-methyl RNAs suggested that there are π-π interactions between two neighboring naphthyl groups in a sequence of the five consecutively modified nucleosides.

Cardiomyocytes fuse with surrounding noncardiomyocytes and reenter the cell cycle.

The concept of the plasticity or transdifferentiation of adult stem cells has been challenged by the phenomenon of cell fusion. In this work, we examined whether neonatal cardiomyocytes fuse with various somatic cells including endothelial cells, cardiac fibroblasts, bone marrow cells, and endothelial progenitor cells spontaneously in vitro. When cardiomyocytes were cocultured with endothelial cells or cardiac fibroblasts, they fused and showed phenotypes of cardiomyocytes. Furthermore, cardiomyocytes reentered the G2-M phase in the cell cycle after fusing with proliferative noncardiomyocytes. Transplanted endothelial cells or skeletal muscle-derived cells fused with adult cardiomyocytes in vivo. In the cryoinjured heart, there were Ki67-positive cells that expressed both cardiac and endothelial lineage marker proteins. These results suggest that cardiomyocytes fuse with other cells and enter the cell cycle by maintaining their phenotypes.

Beating is necessary for transdifferentiation of skeletal muscle-derived cells into cardiomyocytes.

Cell transplantation could be a potential therapy for heart damage. Skeletal myoblasts have been expected to be a good cell source for autologous transplantation; however, the safety and efficacy of their transplantation are still controversial. Recent studies have revealed that skeletal muscle possesses the stem cell population that is distinct from myoblasts. To elucidate whether skeletal muscle stem cells can transdifferentiate into cardiomyocytes, we cocultured skeletal muscle cells isolated from transgenic mice expressing green fluorescent protein with cardiomyocytes of neonatal rats. Skeletal muscle-derived cells expressed cardiac-specific proteins such as cardiac troponin T and atrial natriuretic peptide as well as cardiac-enriched transcription factors such as Nkx2E (formerly called Csx/Nkx2.5) and GATA4 by coculture with cardiomyocytes. Skeletal muscle-derived cells also expressed cadherin and connexin 43 at the junctions with neighboring cardiomyocytes. Cardiomyocyte-like action potentials were recorded from beating skeletal muscle-derived cells. Treatment of nifedipine or culture in Ca2+-free media suppressed contraction of cardiomyocytes and inhibited skeletal muscle cells to express cardiac-specific proteins. Cyclic stretch completely restored this inhibitory effect. These results suggest that some part of skeletal muscle cells can transdifferentiate into cardiomyocytes and that direct cell-to-cell contact and contraction of neighboring cardiomyocytes are important for the transdifferentiation.

Long-term clinical outcomes after sirolimus-eluting stent implantation in dialysis patients.

There is little information about long-term (> 1 year) outcomes after sirolimus-eluting stent (SES) implantation in dialysis patients. Percutaneous coronary intervention (PCI) using SES was performed in 63 dialysis patients with 77 lesions. A control group for comparison was composed of 45 consecutive dialysis patients with 62 lesions who received PCI using bare metal stents (BMS). Clinical follow-up duration was 21.7 +/- 8.4 months in the SES group and 32.1 +/- 9.2 months in the BMS group (P < 0.01). There was no significant difference in the in-segment restenosis rate (30% versus 40%, P = 0.20) between the 2 groups. The 3-year mortality (22.5% versus 22.2%, P = 0.75), myocardial infarction (3.8% versus 4.9%, P = 0.93), target lesion revascularization (24.7% versus 31.0%, P = 0.61), and stent thrombosis rates (3.8% versus 2.4%, P = 0.73) were not significantly different between the SES and BMS groups. Compared to BMS, SES do not improve long-term clinical outcomes in dialysis patients.

Microwave-assisted synthesis of 2'-O-aryluridine derivatives.

A new method for the synthesis of 2'-O-aryluridines was developed via the microwave-mediated reaction of 2,2'-anhydrouridine with aromatic alcohols. Aminophenol and aminonaphthol derivatives underwent selective 2'-O-arylation with 2,2'-anhydrouridine to produce 2'-O-(aminoaryl)uridine derivatives. These reactions proved to proceed without the need for any bases or solvents, but better results were obtained by use of N,N-dimethylacetamide (DMA) as the solvent in some cases.

Synthesis and properties of new RNA molecules incorporating 2'-O-aryluridine derivatives.

A variety of 2'-O-arylnucleosides with functional groups were synthesized by the microwave-assisted reaction of 2,2'-anhydrouridine with phenol derivatives. The 2'-O-arylnucleosides thus obtained were incorporated into 2'-O-Me RNA or DNA oligomers and their hybridization properties were studied by T(m) measurements.

Impact of drug-eluting stents on clinical and angiographic outcomes in dialysis patients.

BACKGROUND: It remains unclear whether sirolimus-eluting stents (SES) have an advantage over bare metal stents (BMS) in patients on dialysis. METHODS AND RESULTS: Percutaneous coronary intervention (PCI) using SES was performed in 54 dialysis patients with 69 lesions. A control group for comparison comprised 54 consecutive dialysis patients with 58 lesions who underwent PCI using BMS. Angiographic and clinical follow-ups were scheduled at 9 months. After the procedure, minimum lumen diameter (MLD) was similar between the 2 groups. At follow-up, the SES group had a higher MLD than the BMS group (1.98+/-0.83 mm vs 1.50+/-0.78 mm, p<0.01). In-stent restenosis rate was lower in lesions treated with SES than in those with BMS (22% vs 40%, p=0.048). However, there was no significant difference between the 2 groups for in-segment restenosis (31% vs 43%, p=0.3). During follow-up, there was no significant difference in the incidence of death, myocardial infarction or target lesion revascularization (TLR) (14% vs 21%, p=0.4) between the SES and BMS groups. CONCLUSIONS: In this retrospective study, SES, in comparison with BMS, reduced in-stent restenosis in patients on dialysis. However, in-segment restenosis and TLR were not statistically different between lesions treated with SES and those with BMS.

Inhibition of G protein-coupled receptor trafficking in neuroblastoma cells by MAP 4 decoration of microtubules.

One mechanism for the reappearance of G protein-coupled receptors after agonist activation is microtubule-based transport. In pressure-overload cardiac hypertrophy, there is downregulation of G protein-coupled receptors and the appearance of a densified microtubule network extensively decorated by a microtubule-associated protein, MAP 4. Our hypothesis is that overdecoration of a dense microtubule network with this structural protein, as in hypertrophied myocardium, would impede receptor recovery. We tested this hypothesis by studying muscarinic acetylcholine receptor (mAChR) internalization and recovery after agonist stimulation in neuroblastoma cells. Exposure of cells to carbachol, a muscarinic receptor agonist, decreased membrane receptor binding activity. After carbachol withdrawal, receptor binding recovered toward the initial value. When microtubules were depolymerized before carbachol withdrawal, mAChR recovery was only 44% of that in intact cells. Cells were then infected with an adenovirus containing MAP 4 cDNA. MAP 4 protein decorated the microtubules extensively, and receptor recovery upon carbachol withdrawal was reduced to 54% of control. Thus muscarinic receptor recovery after agonist exposure is microtubule dependent, and MAP 4 decoration of microtubules inhibits receptor recovery.

c-Raf/MEK/ERK pathway controls protein kinase C-mediated p70S6K activation in adult cardiac muscle cells.

p70S6 kinase (S6K1) plays a pivotal role in hypertrophic cardiac growth via ribosomal biogenesis. In pressure-overloaded myocardium, we show S6K1 activation accompanied by activation of protein kinase C (PKC), c-Raf, and mitogen-activated protein kinases (MAPKs). To explore the importance of the c-Raf/MAPK kinase (MEK)/MAPK pathway, we stimulated adult feline cardiomyocytes with 12-O-tetradecanoylphorbol-13-acetate (TPA), insulin, or forskolin to activate PKC, phosphatidylinositol-3-OH kinase, or protein kinase A (PKA), respectively. These treatments resulted in S6K1 activation with Thr-389 phosphorylation as well as mammalian target of rapamycin (mTOR) and S6 protein phosphorylation. Thr-421/Ser-424 phosphorylation of S6K1 was observed predominantly in TPA-treated cells. Dominant negative c-Raf expression or a MEK1/2 inhibitor (U0126) treatment showed a profound blocking effect only on the TPA-stimulated phosphorylation of S6K1 and mTOR. Whereas p38 MAPK inhibitors exhibited only partial effect, MAPK-phosphatase-3 expression significantly blocked the TPA-stimulated S6K1 and mTOR phosphorylation. Inhibition of mTOR with rapamycin blocked the Thr-389 but not the Thr-421/Ser-424 phosphorylation of S6K1. Therefore, during PKC activation, the c-Raf/MEK/extracellular signal-regulated kinase-1/2 (ERK1/2) pathway mediates both the Thr-421/Ser-424 and the Thr-389 phosphorylation in an mTOR-independent and -dependent manner, respectively. Together, our in vivo and in vitro studies indicate that the PKC/c-Raf/MEK/ERK pathway plays a major role in the S6K1 activation in hypertrophic cardiac growth.

Role of microtubules versus myosin heavy chain isoforms in contractile dysfunction of hypertrophied murine cardiocytes.

In large mammals there is a correlation between microtubule network densification and contractile dysfunction in severe pressure-overload hypertrophy. In small mammals there is a similar correlation for the shift to beta-myosin heavy chain (MHC), a MHC isoform having a slower ATPase Vmax. In this study, murine left ventricular (LV) pressure overload invoked both mechanisms: microtubule network densification and beta-MHC expression. Cardiac beta-MHC was also augmented without altering tubulin levels by two load-independent means, chemical thyroidectomy and transgenesis. In hypertrophy, contractile function of the LV and its cardiocytes decreased proportionally; microtubule depolymerization restored normal cellular contraction. In hypothyroid mice having a complete shift from alpha-MHC to beta-MHC, contractile function of the LV and its cardiocytes also decreased, but microtubule depolymerization had no effect on cellular contraction. In transgenic mice having a cardiac beta-MHC increase similar to that in hypertrophy, contractile function of the LV and its cardiocytes was normal, and microtubule depolymerization had no effect. Thus, although both mechanisms may cause contractile dysfunction, for the extent of MHC isoform switching seen even in severe murine LV pressure-overload hypertrophy, microtubule network densification appears to have the more important role.