Cadmium uptake, chemical forms, subcellular distribution, and accumulation in Echinodorus osiris Rataj

Phytoremediation is a technology for extracting or inactivating pollutants in soil. Echinodorus osiris (E. osiris) is a fast growing perennial wetland plant that is common in tropical and subtropical areas and has a high tolerance to cadmium (Cd). However, the absorption dynamics, subcellular distribution and accumulation of Cd by E. osiris had not been investigated. In this paper, hydroponic experiments with different levels of Cd(2+) (0, 5.0, 15.0 mg L(-1)) were carried out to determine these characteristics of E. osiris. The results indicated that the Cd absorption rate of Echinodorus osiris decreased over time, and the absorption rate within 0.5-1.0 h was faster than after 1.0 h. In a 6.0 hour time period, the rate of Cd uptake fit a quadratic polynomial curve when E. osiris was grown under the 5 mg L(-1) Cd treatment. However, the rate of Cd uptake by E. osiris fit a cubic polynomial model with the 15 mg L(-1) Cd treatment. In the roots, the ethanol-extractable Cd, water-extractable Cd, and NaCl-extractable Cd were the largest proportions of the total Cd. The HAc-extractable Cd, HCl-extractable Cd, and residual-Cd represented a larger proportion of the total Cd in the leaves which was combined with phosphate including CdHPO4, Cd3 (PO4)2, and oxalic acid. When analyzing the subcellular distribution of Cd in the plant, the soluble fraction containing Cd accounted for the largest part (69.49-88.39%) followed by the Cd bound to the cell wall (8.44-25.62%). Both the lower and the higher Cd treatments demonstrated that compartmentation by the vacuole and cell wall binding were two effective defense mechanisms of the plant. However, the vacuole became the main site for Cd accumulation in the leaves under the 15 mg L(-1) Cd treatment. E. osiris was able to accumulate high concentrations of Cd in both the roots and the leaves. The Cd concentration reached 502.97 mg kg(-1) and 2742.95 mg kg(-1) in the shoots and roots, respectively, after 27 days of cultivation. It was concluded that E. osiris is a potential hyperaccumulator of Cd.

Bisphosphonates-related osteonecrosis of the jaw in Korea: a preliminary report

Objectives

Bisphosphonates (BP) are widely used in medicine for inhibiting bone resorption; however bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a major side effect of BP. To date, there have been no specific reports on the incidence of BRONJ among Koreans. This study investigated the preliminary results from a nationwide survey of BRONJ in the Departments of Oral and Maxillofacial Surgery (OMFS) at individual training hospitals.

Materials and Methods

A total of 15 OMFS departments (10 from dental schools, 4 from medical schools, and 1 from a dental hospital) participated in a multi-centric survey. This study assessed every BRONJ case diagnosed between January 2010 and December 2010. The patient age and BP type were evaluated.

Results

A total of 254 BRONJ cases were collected. The majority of BRONJ cases were associated with oral BP therapy, while 21.8% of the cases were associated with intravenous administration. Alendronate was the drug most frequently related to BRONJ (59.2% of cases), followed by risedronate (14.3%) and zolendronate (17.0%). The average age of BRONJ patients was 70.0±10.1 years, with a range of 38-88 years of age. With the number of BP patients in Korea reported to be around 600,000 in 2008, the estimated incidence of BRONJ is at least 0.04% or 1 per 2,300 BP patients.

Conclusion

The results suggest that the estimated incidence of BRONJ in Korea is higher than the incidence of other countries. Future prospective studies should be carried out to investigate the exact epidemiological characteristics of BRONJ in Korea.

Nanofibrous scaffold-mediated REST knockdown to enhance neuronal differentiation of stem cells

At present, the recovery prospect for patients with chronic neurodegenerative diseases or acute trauma in the central nervous system is sub-optimal. The controlled differentiation of neural stem/progenitor cells (NPCs) to functional neurons is a possible treatment strategy. In contrast to the classical approach of biochemicals supplementation for guided stem cell commitment, this study explores the feasibility of directing neuronal differentiation through synergistic integration of three-dimensional nanofibrous topographical cues and scaffold-mediated knockdown of RE-1 silencing transcription factor (REST) in mouse NPCs. Taking advantage of the strong adhesive property and latent reactivity of mussel-inspired polydopamine (PD) coating, electrospun polycaprolactone (PCL) nanofibers were successfully functionalized with REST siRNAs (denoted as siREST PD-fiber). Sustained REST knockdown in NPCs was achieved for up to five days in vitro and the silencing efficiency was significantly higher than that mediated through siRNA adsorption onto non-PD coated sample controls. The silencing of REST, together with nanofiber topographical effect, significantly enhanced NPC neuronal commitment (57.5% Map2(+) cells in siREST PD-fiber vs. 43.5% in siREST PD-film vs. 50% in PD-fiber controls, p < 0.05) while reducing astrocytic and oligodendrocytic differentiation (10.7% O4(+) cells vs. ∼30% in siREST PD-film, p < 0.01). Taken together, the synergistic effects of scaffold-mediated REST knockdown and topographical cues from PD-modified nanofibers may be a useful strategy for generating functional neurons for therapeutic purposes.

Long-distance signaling in bypass1 mutants: bioassay development reveals the bps signal to be a metabolite

Root-to-shoot signaling is used by plants to coordinate shoot development with the conditions experienced by the roots. A mobile and biologically active compound, the bps signal, is over-produced in roots of an Arabidopsis thaliana mutant called bypass1 (bps1), and might also be a normally produced signaling molecule in wild-type plants. Our goal is to identify the bps signal chemically, which will then allow us to assess its production in normal plants. To identify any signaling molecule, a bioassay is required, and here we describe the development of a robust, simple, and quantitative bioassay for the bps signal. The developed bioassay follows the growth-reducing activity of the bps signal using the pCYCB1;1::GUS cell cycle marker. Wild-type plants carrying this marker, and provided the bps signal through either grafts or metabolite extracts, showed reduced cell division. By contrast, control grafts and treatment with control extracts showed no change in pCYCB1;1::GUS expression. To determine the chemical nature of the bps signal, extracts were treated with RNase A, Proteinase K, or heat. None of these treatments diminished the activity of bps1 extracts, suggesting that the active molecule might be a metabolite. This bioassay will be useful for future biochemical fractionation and analysis directed toward bps signal identification.

Porcine feasibility and safety study of a new paclitaxel-eluting biliary stent with a Pluronic-containing membrane

BACKGROUND AND STUDY AIM

Metal stents for malignant biliary obstruction are susceptible to occlusion by tumor ingrowth or overgrowth. Therefore, we previously reported our use of a metal stent covered with a paclitaxel-incorporated membrane giving an antitumor effect to prevent occlusion from tumor ingrowth. We have also developed a new generation of paclitaxel-eluting biliary stent using a membrane containing Pluronic F-127 for effective drug delivery. The aim of this study was to investigate the safety and efficacy of drug delivery for this newly developed stent in the biliary tract.

METHODS

Metal stents were coated with paclitaxel and various concentrations of Pluronic F-127 in phosphate-buffered saline solution. Stents containing varying concentrations were placed in the bile ducts of eight pigs divided as follows: group I, 0% Pluronic + 0% paclitaxel; group II, 0% Pluronic + 10% paclitaxel; group III, 10% Pluronic + 10% paclitaxel; group IV, 20% Pluronic + 10% paclitaxel. The histology of the porcine bile duct and the amount of paclitaxel in the porcine serum were examined. The amount of paclitaxel released was also measured in vitro.

RESULTS

Histologic changes in the porcine biliary epithelium were acceptable in terms of safety, based on inflammatory cell infiltration and fibrotic reaction. No significant differences in histology were observed between the groups. In the porcine serum analysis, released paclitaxel was detected for 28 days with the 10% Pluronic concentration (group III). However, released paclitaxel was observed for only 7 days in groups II and IV. In the in vitro experiments, long-lasting release of paclitaxel was also noted from the stent with 10% Pluronic.

CONCLUSIONS

The new paclitaxel-eluting stent with 10% Pluronic F-127 is safe and provides enhanced local drug delivery.

The bps signal: embryonic arrest from an auxin-independent mechanism in bypass triple mutants

Long-distance signaling is essential for coordination of plant development and environmental responses. We originally isolated a tiny mutant named bypass1 (bps1), which has defects in shoot and root development. The bps1 roots overproduce a mobile signal (bps signal) that arrests both root and shoot development. Our recent study demonstrated that all three BPS gene family members prevent ectopic synthesis of the same bps signal.bps multiple mutants show progressively more severe developmental defects. An embryogenesis analysis revealed abnormal cell divisions in all meristem lineages of bps triple mutants. These defects appear to be auxin independent, and arise prior to changes in PLT1 and PLT2 expression.

In the absence of BYPASS1-related gene function, the bps signal disrupts embryogenesis by an auxin-independent mechanism

Development is often coordinated by biologically active mobile compounds that move between cells or organs. Arabidopsis mutants with defects in the BYPASS1 (BPS1) gene overproduce an active mobile compound that moves from the root to the shoot and inhibits growth. Here, we describe two related Arabidopsis genes, BPS2 and BPS3. Analyses of single, double and triple mutants revealed that all three genes regulate production of the same mobile compound, the bps signal, with BPS1 having the largest role. The triple mutant had a severe embryo defect, including the failure to properly establish provascular tissue, the shoot meristem and the root meristem. Aberrant expression of PINFORMED1, DR5, PLETHORA1, PLETHORA2 and WUSCHEL-LIKE HOMEOBOX5 were found in heart-stage bps triple-mutant embryos. However, auxin-induced gene expression, and localization of the PIN1 auxin efflux transporter, were intact in bps1 mutants, suggesting that the primary target of the bps signal is independent of auxin response. Thus, the bps signal identifies a novel signaling pathway that regulates patterning and growth in parallel with auxin signaling, in multiple tissues and at multiple developmental stages.

Facile, high efficiency immobilization of lipase enzyme on magnetic iron oxide nanoparticles via a biomimetic coating

BACKGROUND

Immobilization of lipase on appropriate solid supports is one way to improve their stability and activity, and can be reused for large scale applications. A sample, cost- effective and high loading capacity method is still challenging.

RESULTS

A facile method of lipase immobilization was developed in this study, by the use of polydopamine coated magnetic nanoparticles (PD-MNPs). Under optimal conditions, 73.9% of the available lipase was immobilized on PD-MNPs, yielding a lipase loading capacity as high as 429 mg/g. Enzyme assays revealed that lipase immobilized on PD-MNPs displayed enhanced pH and thermal stability compared to free lipase. Furthermore, lipase immobilized on PD-MNPs was easily isolated from the reaction medium by magnetic separation and retained more than 70% of initial activity after 21 repeated cycles of enzyme reaction followed by magnetic separation.

CONCLUSIONS

Immobilization of enzyme onto magnetic iron oxide nanoparticles via poly-dopamine film is economical, facile and efficient.

Deformation characteristics of an organic thin film transistor

An organic thin film transistor (OTFT) on a flexible substrate with electroplated electrodes has many advantages in the fabrication of low cost sensors, e-paper, smart cards, and flexible displays. In this study, we simulated the mechanical characteristics of an OTFT with various compressive stress conditions using COMSOL. An analysis model, which was limited to channel, source, and drain, was used to investigate deformation and internal stress concentrations. The channel length is 40 microm and the OTFT structure is a top-contact structure. The OTFT was fabricated using pentacene as a semiconducting layer and electroplated Ni as a gate electrode. The deformation characteristics of the fabricated OTFT were predicted in terms of strain and internal stress.

HY253, a novel decahydrofluorene analog, from Aralia continentalis, induces cell cycle arrest at the G1 phase and cytochrome c-mediated apoptosis in human lung cancer A549 cells

AIM OF THE STUDY

In the course of our screening for novel modulators on cell cycle progression and apoptosis as anticancer drug candidates, we isolated a novel compound HY253 with the molecular structure of 7,8a-divinyl-2,4a,4b,5,6,7,8,8a,9,9a-decahydro-1H-fluorene-2,4a,4b,9a-tetraol from the roots of Aralia continentalis. This study was designed to evaluate the detailed mechanisms of cell cycle arrest and the apoptotic induction of HY253 in human lung cancer A549 cells.

MATERIALS AND METHODS

To investigate the effects of HY253 on cell cycle progression in A549 cells, we measured DNA content of A549 cells treated with 35 microM of HY253 using flow cytometric analysis. Furthermore, TUNEL assay was used to examine apoptotic induction in A549 cells treated with 70 microM of HY253 for 24 and 48 h. The effects of HY253 on apoptosis-associated and cell cycle regulatory proteins in A549 cells were examined using Western blot analysis.

RESULTS

The flow cytometric analysis revealed an appreciable G(1) phase arrest in A549 cells treated with 35 microM of HY253. This HY253-induced G(1) phase arrest is associated with decreased expression of cyclin D and up-regulation of p21(CIP1), via p53 phosphorylation at Ser-15, which resulted in increased hypophosphorylated pRb in A549 cells. Furthermore, TUNEL assay and Western blot analysis revealed an appreciable apoptotic induction in A549 cells treated with 70 microM of HY253 for 48 h. This apoptotic induction in HY253-treated A549 cells is also associated with cytochrome c release from mitochondria which in turn resulted in the activation of caspase-9 and -3, and the cleavage of poly(ADP-ribose) polymerase (PARP).

CONCLUSIONS

These results demonstrate that HY253, a novel antiproliferative compound isolated from the roots of Aralia continentalis, induces cell cycle arrest at the G(1) phase and apoptosis in A549 cells. Based on these results, we suggest that HY253 may be a potent cancer chemotherapeutic candidate for use in treating human lung cancer cells via up-regulation and activation of p53 gene.

Cell cycle arrest and cytochrome c-mediated apoptotic induction in human lung cancer A549 cells by MCS-C2, an analogue of sangivamycin

In the course of our screening for novel modulators on cell cycle progression and apoptosis as anticancer drug candidates, we generated an analogue of sangivamycin, MCS-C2, designated as 4-amino-6-bromo-7-cyclopentyl-7H-pyrrolo[2,3-d]pyrimidine-5-carboxamide. This study was aimed to evaluate the molecular mechanisms on cell cycle arrest and apoptotic induction of MCS-C2 in human lung cancer A549 cells. To investigate the effects of MCS-C2 on cell cycle progression in A549 cells, we measured DNA content of A549 cells treated with 5 microM of HY253 using flow cytometric analysis. The flow cytometric analysis revealed an appreciable G(2) phase arrest in A549 cells treated with 5 micronM of MCS-C2. This MCS-C2-induced G(2) phase arrest is associated with significant up-regulation of p53 and p21(Cip1) in A549 cells. Furthermore, TUNEL assay was used to examine apoptotic induction in A549 cells treated with 5 microM of MCS-C2 for 48 h. In addition, the effects of MCS-C2 on apoptosis-associated proteins in A549 cells were examined using Western blot analysis. The apoptotic induction in MCS-C2-treated A549 cells is associated with cytochrome c release from mitochondria which in turn resulted in the activation of caspase-9 and -3, and the cleavage of poly(ADP-ribose) polymerase (PARP). In conclusion, based on these results, we suggest that MCS-C2 may be a potent cancer chemotherapeutic candidate for use in treating human lung cancer cells via up-regulation and activation of p53.

BYPASS1: how a tiny mutant tells a big story about root-to-shoot signaling

Plants coordinate their development using long-distance signaling. The vascular system provides a route for long-distance movement, and specifically the xylem for root-to-shoot signaling. Root-to-shoot signals play roles communicating soil conditions, and these signals are important for agricultural water conservation. Using genetic approaches, the Arabidopsis bypass1 (bps1) mutant, which over-produces a root-derived signal, was identified. Although bps1 mutants have both root and shoot defects, the shoot can develop normally if the roots are removed, and the mutant root is sufficient to induce arrest of the wild-type shoot. BYPASS1 encodes a protein with no functionally characterized domains, and BPS1-like genes are found in plant genomes, but not the genomes of animals. Analyses of hormone pathways indicate that the mobile compound that arises in bps1 roots requires carotenoid biosynthesis, but it is neither abscisic acid nor strigolactone. The current model suggests that BPS1 is required to prevent the synthesis of a novel substance that moves from the root to the shoot, where it modifies shoot growth by interfering with auxin signaling.

Celecoxib induces hepatic stellate cell apoptosis through inhibition of Akt activation and suppresses hepatic fibrosis in rats

BACKGROUND AND AIMS

Activated hepatic stellate cells (HSCs) but not quiescent HSCs express cyclo-oxygenase-2 (COX-2), suggesting that the COX-2/prostanoid pathway has an active role in hepatic fibrogenesis. However, the role of COX-2 inhibitors in hepatic fibrogenesis remains controversial. The aim of this study was to investigate the antifibrotic effects of celecoxib, a selective COX-2 inhibitor.

METHODS

The effects of various COX inhibitors-that is, ibuprofen, celecoxib, NS-398 and DFU, were investigated in activated human HSCs. Then, the antifibrotic effect of celecoxib was evaluated in hepatic fibrosis developed by bile duct ligation (BDL) or peritoneal thioacetamide (TAA) injection in rats.

RESULTS

Celecoxib, NS-398 and DFU inhibited platelet-derived growth facor (PDGF)-induced HSC proliferation; however, only celecoxib (> or =50 microM) induced HSC apoptosis. All COX inhibitors completely inhibited prostaglandin E(2) (PGE(2)) and PGI(2) production in HSCs. Separately, PGE(2) and PGI(2) induced cell proliferation and extracellular signal-regulated kinase (ERK) activation in HSCs. All COX inhibitors attenuated ERK activation, but only celecoxib significantly inhibited Akt activation in HSCs. Celecoxib-induced apoptosis was significantly attenuated in HSCs infected with adenovirus containing a constitutive active form of Akt (Ad5myrAkt). Celecoxib had no significant effect on PPARgamma (peroxisome proliferator-activated receptor gamma) expression in HSCs. Celecoxib inhibited type I collagen mRNA and protein production in HSCs. Oral administration of celecoxib (20 mg/kg/day) significantly decreased hepatic collagen deposition and alpha-SMA (alpha-smooth muscle actin) expression in BDL- and TAA-treated rats. Celecoxib treatment significantly decreased mRNA expression of COX-2, alpha-SMA, transforming growth factor beta1 (TGFbeta1) and collagen alpha1(I) in both models.

CONCLUSIONS

Celecoxib shows a proapoptotic effect on HSCs through Akt inactivation and shows antifibrogenic effects in BDL- and TAA-treated rats, suggesting celecoxib as a novel antifibrotic agent of hepatic fibrosis.

LATERAL ORGAN FUSION1 and LATERAL ORGAN FUSION2 function in lateral organ separation and axillary meristem formation in Arabidopsis

Plant organs are generated from meristems throughout development. Patterning and elaboration of organ primordia occur as a result of organized cell division and expansion, processes that are likely to be controlled, in part, by meristem-derived signals. Communication between the meristem and lateral organs is crucial for meristem maintenance and organ patterning, and organ boundaries are thought to be important for mediating this communication. Arabidopsis thaliana LATERAL ORGAN FUSION1 (LOF1) encodes a MYB-domain transcription factor that is expressed in organ boundaries. lof1 mutants display defects in organ separation as a result of abnormal cell division and expansion during early boundary formation. lof1 mutants also fail to form accessory shoot meristems. Mutations in the closely related LATERAL ORGAN FUSION2 (LOF2) gene enhance the lof1 phenotype, such that lof1 lof2 double mutants display additional fusion defects. Genetic interactions with the CUP-SHAPED COTYLEDON genes CUC2 and CUC3 revealed a role for LOF1 in both organ separation and axillary meristem formation. Expression of the meristem determinant STM was reduced in lof1 mutant paraclade junctions and lof1 enhanced the weak stm-10 mutant, such that double mutants had severe defects in meristem maintenance and organ separation. Our data implicate LOF1 and LOF2 in boundary specification, meristem initiation and maintenance, and organ patterning.

Anastomotic leakage after laparoscopic protectomy can be managed by a minimally invasive approach

PURPOSE

This study was designed to identify the clinical features of anastomotic leakage after laparoscopic resection of rectal cancer and to evaluate the outcomes of laparoscopic management for this problem.

METHODS

Prospectively collected data were obtained from 307 patients with rectal cancer who underwent laparoscopic proctectomy and primary anastomosis. Age, sex, tumor location, tumor stage, body mass index, comorbidities, ileostomy, conversion, intraoperative blood loss, operative time, previous abdominal operation, and hospital stay were analyzed for patients with or without anastomotic leakage. Management and outcome of anastomotic leakage also were analyzed.

RESULTS

Anastomotic leakage occurred in 29 patients (9.4 percent). Diverting ileostomy was initially fashioned in 65 patients (21.2 percent). Leakage was related to young age, male sex, lower tumor location, and longer operation time. Ten patients (34.5 percent) were successfully managed with conservative treatment. Seventeen patients (58.6 percent) were managed via a laparoscopic approach. Open surgery was performed in two patients who showed diffuse fecal soiling or had previous conversion, respectively. There was no mortality.

CONCLUSIONS

When leakage occurs, laparotomy or colostomy is not needed routinely. For surgical intervention, the abdominal cavity should be explored first by laparoscopic visualization because the majority of patients can be successfully managed with laparoscopy and ileostomy.

Mechanisms of atomic layer deposition on substrates with ultrahigh aspect ratios

Atomic layer deposition (ALD) appears to be uniquely suited for coating substrates with ultrahigh aspect ratios (> or similar 10(3)), including nanoporous solids. Here, we study the ALD of Cu and Cu3N on the inner surfaces of low-density nanoporous silica aerogel monoliths. Results show that Cu depth profiles in nanoporous monoliths are limited not only by Knudsen diffusion of heavier precursor molecules into the pores, as currently believed, but also by other processes such as the interaction of precursor and reaction product molecules with pore walls. Similar behavior has also been observed for Fe, Ru, and Pt ALD on aerogels. On the basis of these results, we discuss design rules for ALD precursors specifically geared for coating nanoporous solids.

Management of warm-season grass mixtures for biomass production in South Dakota USA

Switchgrass (Panicum virgatum L.), big bluestem (Andropogon gerardii Vitman), and indiangrass (Sorghastrum nutans (L.) Nash) are native warm-season grasses commonly used for pasture, hay, and conservation. More recently switchgrass has also been identified as a potential biomass energy crop, but management of mixtures of these species for biomass is not well documented. Therefore, the objectives of our study were to: (1) determine the effects of harvest timing and N rate on yield and biomass characteristics of established warm-season grass stands containing a mixture of switchgrass, big bluestem, and indiangrass, and (2) evaluate the impact of harvest management on species composition. Five N rates (0, 56, 112, and 224 kg ha(-1) applied annually in spring and 224 kg ha(-1) evenly split between spring and fall) and two harvest timings (anthesis and killing frost) were applied to plots at two South Dakota USA locations from 2001 to 2003. Harvesting once a year shortly after a killing frost produced the greatest yields with high concentrations of neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) along with lower concentrations of total nitrogen (TN) and ash. This harvest timing also allowed for the greatest percentage of desirable species while maintaining low grass weed percentages. While N rates of 56 and 112 kg ha(-1) tended to increase total biomass without promoting severe invasion of grass and broadleaf weed species, N application did not always result in significant increases in biomass production. Based on these results, mixtures of switchgrass and big bluestem were well suited for sustainable biomass energy production. Furthermore, N requirements of these mixtures were relatively low thus reducing production input costs.