A Finite Element Analysis Study of Edentulous Model with Complete Denture to Simulate Masticatory Movement

The purposes of this study are to establish and validate a finite element (FE) model using finite element analysis methods and to identify optimal loading conditions to simulate masticatory movement. A three-dimensional FE model of the maxillary and mandibular cortical bone, cancellous bone, and gingiva was constructed based on edentulous cone-beam-computed tomography data. Dental computer-aided design software was used to design the denture base and artificial teeth to produce a complete denture. Mesh convergence was performed to derive the optimal mesh size, and validation was conducted through comparison with mechanical test results. The mandible was rotated step-by-step to induce movements similar to actual mastication. Results showed that there was less than a 6% difference between the mechanical test and the alveolar bone-complete denture. It opened 10° as set in the first stage, confirming that the mouth closed 7° in the second stage. Occlusal contact occurred between the upper and lower artificial teeth as the mouth closed the remaining angle of 3° in the third stage while activating the masseter muscle. These results indicate that the FE model and masticatory loading conditions developed in this study can be applied to analyze biomechanical effects according to the wearing of dentures with various design elements applied.

SOCS1 counteracts ROS-mediated survival signals and promotes apoptosis by modulating cell cycle to increase radiosensitivity of colorectal cancer cells

As negative regulators of cytokine signaling pathways, suppressors of cytokine signaling (SOCS) proteins have been reported to possess both pro-tumor and anti-tumor functions. Our recent studies have demonstrated suppressive effects of SOCS1 on epithelial to mesenchymal signaling in colorectal cancer cells in response to fractionated ionizing radiation or oxidative stress. The objective of the present study was to determine the radiosensitizing action of SOCS1 as an anti-tumor mechanism in color-ectal cancer cell model. In HCT116 cells exposed to ionizing radiation, SOCS1 over-expression shifted cell cycle arrest from G2/M to G1 and promoted radiation-induced apoptosis in a p53-dependent manner with down-regulation of cyclin B and up-regulation of p21. On the other hand, SOCS1 knock-down resulted in a reduced apoptosis with a decrease in G1 arrest. The regulatory action of SOCS1 on the radiation response was mediated by inhibition of radiation-induced Jak3/STAT3 and Erk activities, thereby blocking G1 to S transition. Radiation-induced early ROS signal was responsible for the activation of Jak3/Erk/STAT3 that led to cell survival response. Our data col-lectively indicate that SOCS1 can promote radiosensitivity of colorectal cancer cells by counteracting ROS-mediated survival signal, thereby blocking cell cycle progression from G1 to S. The resulting increase in G1 arrest with p53 activation then contributes to the promotion of apoptotic response upon radiation. Thus, induction of SOCS1 expression may increase therapeutic efficacy of radiation in tumors with low SOCS1 levels.

SOCS1 counteracts ROS-mediated survival signals and promotes apoptosis by modulating cell cycle to increase radiosensitivity of colorectal cancer cells

As negative regulators of cytokine signaling pathways, suppressors of cytokine signaling (SOCS) proteins have been reported to possess both pro-tumor and anti-tumor functions. Our recent studies have demonstrated suppressive effects of SOCS1 on epithelial to mesenchymal signaling in colorectal cancer cells in response to fractionated ionizing radiation or oxidative stress. The objective of the present study was to determine the radiosensitizing action of SOCS1 as an anti-tumor mechanism in colorectal cancer cell model. In HCT116 cells exposed to ionizing radiation, SOCS1 over-expression shifted cell cycle arrest from G2/M to G1 and promoted radiation-induced apoptosis in a p53-dependent manner with down-regulation of cyclin B and up-regulation of p21. On the other hand, SOCS1 knock-down resulted in a reduced apoptosis with a decrease in G1 arrest. The regulatory action of SOCS1 on the radiation response was mediated by inhibition of radiation-induced Jak3/STAT3 and Erk activities, thereby blocking G1 to S transition. Radiation-induced early ROS signal was responsible for the activation of Jak3/Erk/STAT3 that led to cell survival response. Our data collectively indicate that SOCS1 can promote radiosensitivity of colorectal cancer cells by counteracting ROS-mediated survival signal, thereby blocking cell cycle progression from G1 to S. The resulting increase in G1 arrest with p53 activation then contributes to the promotion of apoptotic response upon radiation. Thus, induction of SOCS1 expression may increase therapeutic efficacy of radiation in tumors with low SOCS1 levels. [BMB Reports 2022; 55(4): 198-203].

Photo-induced Reactive Oxygen Species Activation for Amorphous Indium-Gallium-Zinc Oxide Thin-Film Transistors Using Sodium Hypochlorite

We proposed a novel material named sodium hypochlorite (NaClO) solution as a source of activation for amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs). We reduced the activation temperature from 300 to 150 °C using NaClO solution (concentration: 50%) and obtained satisfactory electrical characteristics of a-IGZO TFTs. The field-effect mobility, threshold voltage, on/off ratio, subthreshold swing, and threshold voltage (V_th) shift under negative bias illumination stress (V_G = -20 V and V_D = 10.1 V for 10,000 s) of NaClO (50%)-activated a-IGZO TFTs were 10.41 cm²/V·s, 1.51 V, 2.78 × 10⁸, 0.37 V/dec, and -5.43 V, respectively. Also, the V_th shifts of the NaClO (50%)-activated a-IGZO TFTs (150 °C) under the positive bias stress test decreased from 5.01 to 1.87 V (V_G = 20 V and V_D = 10.1 V for 10,000 s) compared with that of only-annealed (300 °C) a-IGZO TFTs. Also, the mechanism of NaClO activation for a-IGZO TFTs is clarified through photo-assisted oxygen radical (POR) and heat-driven oxygen radical (HOR) effects. The POR and HOR effects generated the reactive oxygen species (ROS) from NaClO solution (50%), which activated a-IGZO TFTs at a low temperature (150 °C). When the NaClO solution (50%) was exposed to external energy, it generated ROS such as hydroxyl radicals (OH^•), hydroperoxyl radicals (HO₂^•), and oxygen radicals (O^•), which promoted the formation of strong metal-oxide bonds in a-IGZO TFTs. Furthermore, NaClO solution (50%) was applied to a-IGZO TFTs on a flexible polyimide substrate and electrohydrodynamic printing process for selective deposition.

High Photosensitive Indium-Gallium-Zinc Oxide Thin-Film Phototransistor with a Selenium Capping Layer for Visible-Light Detection

Visible light can be detected using an indium-gallium-zinc oxide (IGZO)-based phototransistor, with a selenium capping layer (SCL) that functions as a visible light absorption layer. Selenium (Se) exhibits photoconductive properties as its conductivity increases with illumination. We report an IGZO phototransistor with an SCL (SCL/IGZO phototransistor) that demonstrated optimal photoresponse characteristics when the SCL was 150 nm thick. The SCL/IGZO phototransistor exhibited a photoresponsivity of 1.39 × 10³ A/W, photosensitivity of 4.39 × 10⁹, detectivity of 3.44 × 10¹³ Jones, and external quantum efficiency of 3.52 × 10³% when illuminated by green light (532 nm). Ultraviolet-visible spectroscopy and ultraviolet photoelectron spectroscopy analysis showed that Se has a narrow energy band gap, in which visible light is absorbed and forms a p-n junction with IGZO so that photogenerated electron-hole pairs are easily separated, which makes recombination more challenging. We show that electrons generated in the SCL flow through the IGZO layer, which enables the phototransistor to detect visible light. Furthermore, the SCL/IGZO phototransistor exhibited excellent durability and reversibility owing to the constant light and dark current and the time-dependent photoresponse characteristics over 8000 s when a red light (635 nm) source was turned on and off at a frequency of 0.1 Hz.

Multifunctional, Room-Temperature Processable, Heterogeneous Organic Passivation Layer for Oxide Semiconductor Thin-Film Transistors

In recent decades, oxide thin-film transistors (TFTs) have attracted a great deal of attention as a promising technology in terms of next-generation electronics due to their outstanding electrical performance. However, achieving robust electrical characteristics under various environments is a crucial challenge for successful realization of oxide-based electronic applications. To resolve the limitation, we propose a highly flexible and reliable heterogeneous organic passivation layer composed of stacked parylene-C and diketopyrrolopyrrole-polymer films for improving stability of oxide TFTs under various environments and mechanical stress. The presented multifunctional heterogeneous organic (MHO) passivation leads to high-performance oxide TFTs by: (1) improving their electrical characteristics, (2) protecting them from external reactive molecules, and (3) blocking light exposure to the oxide layer. As a result, oxide TFTs with MHO passivation exhibit outstanding stability in ambient air as well as under light illumination: the threshold voltage shift of the device is almost 0 V under severe negative bias illumination stress condition (white light of 5700 lx, gate voltage of -20 V, and drain voltage of 10.1 V for 20 000 s). Furthermore, since the MHO passivation layer exhibits high mechanical stability at a bending radius of ≤5 mm and can be deposited at room temperature, this technique is expected to be useful in the fabrication of flexible/wearable devices.

Artificially Fabricated Subgap States for Visible-Light Absorption in Indium-Gallium-Zinc Oxide Phototransistor with Solution-Processed Oxide Absorption Layer

We present a solution-processed oxide absorption layer (SAL) for detecting visible light of long wavelengths (635 and 532 nm) for indium-gallium-zinc oxide (IGZO) phototransistors. The SALs were deposited onto sputtered IGZO using precursor solutions composed of IGZO, which have the same atomic configuration as that of the channel layer, resulting in superior interface characteristics. We artificially generated subgap states in the SAL using a low annealing temperature (200 °C), minimizing the degradation of the electrical characteristics of thin-film transistor. These subgap states improved the photoelectron generation in SALs under visible light of long wavelength despite the wide band gap of IGZO (∼3.7 eV). As a result, IGZO phototransistors with SALs have both high optical transparency and superior optoelectronic characteristics such as a high photoresponsivity of 206 A/W and photosensitivity of ∼10⁶ under the influence of a green (532 nm) laser. Furthermore, endurance tests proved that the IGZO phototransistor with SALs can operate stably under red laser illumination switched on and off at 0.05 Hz for 7200 s.

High-Throughput Open-Air Plasma Activation of Metal-Oxide Thin Films with Low Thermal Budget

Sputter-processed oxide films are typically annealed at high temperature (activation process) to achieve stable electrical characteristics through the formation of strong metal-oxide chemical bonds. For instance, indium-gallium-zinc oxide (IGZO) films typically need a thermal treatment at 300 °C for ≥1 h as an activation process. We propose an open-air plasma treatment (OPT) to rapidly and effectively activate sputter-processed IGZO films. The OPT effectively induces metal-oxide chemical bonds in IGZO films at temperatures as low as 240 °C, with a dwell time on the order of a second. Furthermore, by controlling the plasma-processing conditions (scan speed, distance a between plasma nozzle and samples, and gas flow rate), the electrical characteristics and the microstructure of the IGZO films can be easily tuned. Finally, OPT can be utilized to implement a selective activation process. Plasma-treated IGZO thin-film transistors (TFTs) exhibit comparable electrical characteristics to those of conventionally thermal treated IGZO TFTs. Through in-depth optical, chemical, and physical characterizations, we confirm that OPT simultaneously dissociates weak chemical bonds by UV radiation and ion bombardment and re-establishes the metal-oxide network by radical reaction and OPT-induced heat.

Effect of Static and Rotating Magnetic Fields on Low-Temperature Fabrication of InGaZnO Thin-Film Transistors

We suggest thermal treatment with static magnetic fields (SMFs) or rotating magnetic fields (RMFs) as a new technique for the activation of indium-gallium-zinc oxide thin-film transistors (IGZO TFTs). Magnetic interactions between metal atoms in IGZO films and oxygen atoms in air by SMFs or RMFs can be expected to enhance metal-oxide (M-O) bonds, even at low temperature (150 °C), through attraction of metal and oxygen atoms having their magnetic moments aligned in the same direction. Compared to IGZO TFTs with only thermal treatment at 300 °C, IGZO TFTs under an RMF (1150 rpm) at 150 °C show superior or comparable characteristics: field-effect mobility of 12.68 cm² V^-1 s^-1, subthreshold swing of 0.37 V dec^-1, and on/off ratio of 1.86 × 10⁸. Although IGZO TFTs under an SMF (0 rpm) can be activated at 150 °C, the electrical performance is further improved in IGZO TFTs under an RMF (1150 rpm). These improvements of IGZO TFTs under an RMF (1150 rpm) are induced by increases in the number of M-O bonds due to enhancement of the magnetic interaction per unit time as the rpm value increases. We suggest that this new process of activating IGZO TFTs at low temperature widens the choice of substrates in flexible or transparent devices.

Boosting Visible Light Absorption of Metal-Oxide-Based Phototransistors via Heterogeneous In-Ga-Zn-O and CH3NH3PbI3 Films

To broaden the availability and application of metal-oxide (M-O)-based optoelectronic devices, we suggest heterogeneous phototransistors composed of In-Ga-Zn-O (IGZO) and methylammonium lead iodide (CH₃NH₃PbI₃) layers, which act as the amplifier layer (channel layer) and absorption layer, respectively. These heterogeneous phototransistors showed low persistence photocurrent compared with IGZO-only phototransistors and exhibited high photoresponsivity of 61 A/W, photosensitivity of 3.48 × 10⁶, detectivity of 9.42 × 10¹⁰ Jones, external quantum efficiency of 154% in an optimized structure, and high photoresponsivity under water exposure via the deposition of silicon dioxide as a passivation layer. On the basis of these electrical results and various analyses, we determined that CH₃NH₃PbI₃ could be activated as a light absorption layer, current barrier, and plasma damage blocking layer, which would serve to widen the range of applications of M-O-based optoelectronic devices with high photoresponsivity and reliability under visible light illumination.

Facile fabrication of wire-type indium gallium zinc oxide thin-film transistors applicable to ultrasensitive flexible sensors

We fabricated wire-type indium gallium zinc oxide (IGZO) thin-film transistors (TFTs) using a self-formed cracked template based on a lift-off process. The electrical characteristics of wire-type IGZO TFTs could be controlled by changing the width and density of IGZO wires through varying the coating conditions of template solution or multi-stacking additional layers. The fabricated wire-type devices were applied to sensors after functionalizing the surface. The wire-type pH sensor showed a sensitivity of 45.4 mV/pH, and this value was an improved sensitivity compared with that of the film-type device (27.6 mV/pH). Similarly, when the wire-type device was used as a glucose sensor, it showed more variation in electrical characteristics than the film-type device. The improved sensing properties resulted from the large surface area of the wire-type device compared with that of the film-type device. In addition, we fabricated wire-type IGZO TFTs on flexible substrates and confirmed that such structures were very resistant to mechanical stresses at a bending radius of 10 mm.

Simple Hydrogen Plasma Doping Process of Amorphous Indium Gallium Zinc Oxide-Based Phototransistors for Visible Light Detection

A homojunction-structured amorphous indium gallium zinc oxide (a-IGZO) phototransistor that can detect visible light is reported. The key element of this technology is an absorption layer composed of hydrogen-doped a-IGZO. This absorption layer is fabricated by simple hydrogen plasma doping, and subgap states are induced by increasing the amount of hydrogen impurities. These subgap states, which lead to a higher number of photoexcited carriers and aggravate the instability under negative bias illumination stress, enabled the detection of a wide range of visible light (400-700 nm). The optimal condition of the hydrogen-doped absorption layer (HAL) is fabricated at a hydrogen partial pressure ratio of 2%. As a result, the optimized a-IGZO phototransistor with the HAL exhibits a high photoresponsivity of 1932.6 A/W, a photosensitivity of 3.85 × 10⁶, and a detectivity of 6.93 × 10¹¹ Jones under 635 nm light illumination.

Comparative Analysis of Frozen and Acellularized Vascular Xenografts

Background

We implanted frozen and acellularized porcine xenograft vessels as small-diameter arterial grafts in goats and comparatively analyzed the explanted grafts by gross observation and by light microscopy at predetermined periods.

Materials and Methods

Porcine carotid arteries were harvested and immediately stored within a tissue preservation solution at −70°C in a freezer designated for frozen xenograft vessels. The acellularized xenograft vessels were prepared with NaCl-SDS solution and stored frozen until use. One pair of porcine xenograft vessels were used to compare the frozen and acellularized grafts in the bilateral carotid arteries in one goat. The grafts were implanted for one, 3, and 6 months in three animals. Periodic ultrasonographic examinations were performed during the observation period. Explanted grafts were analyzed by gross observation, and by light microscopy.

Results

All animals survived the experimental procedure without specific problems. Ultrasonographic examinations showed excellent patency in all grafts during the observation period. Gross observations revealed nonthrombotic patent smooth lumens. Microscopic examinations of the explanted grafts showed satisfactory cellular reconstruction to the 6-month stage. Although more inflammatory responses were observed in the early phase of implantation of frozen xenografts than of acellularized xenografts, there was no evidence of significant rejection of the frozen xenografts.

Conclusion

These findings suggest that porcine vessel xenografts, regardless of them being acellularized or simply frozen xenografts, can be acceptably implanted in goats as a form of small-diameter vascular graft.

Tissue-Engineered Acellularized Valve Xenografts: A Comparative Animal Study between Plain Acellularized Xenografts and Autologous Endothelial Cell Seeded Acellularized Xenografts

Background

Acellularized valve xenografts are considered a promising way of overcoming the inherent limitations of current prosthetic valves. The aim of this study was to compare the biological responses of an autologous endothelial cell seeded acellularized xenograft (AAX) and a plain acellularized xenograft (PAX) implanted in the pulmonary valve leaflet in the same animal.

Methods

Endothelial cells were isolated and cultured from the jugular vein of goats. Porcine valve leaflets were acellularized with Nacl-SDS, and for AAX, leaflets were then seeded with autologous endothelial cells. A PAX and an AAX were implanted as double pulmonary valve leaflet replacement in the same animal in a goat model (n=6). After sacrifice, the implanted valve leaflet tissues were retrieved and analyzed visually and under a light microscope.

Results and Conclusions

Six animals were sacrificed as scheduled during the short-term (6 and 24 hours), mid-term (1 week and 1 month) and long-term (3 and 6 months). Gross and ultrasonographic examinations revealed good valve function with no thrombosis but with slight thickening. Microscopic analysis of the leaflets showed abundant cellular ingrowth into the acellularized leaflets over time. The role of endothelial cell seeding remains controversial. This animal experiment demonstrates the practical feasibility of using acellularized valve xenografts.

Improvement of Electrical Characteristics and Stability of Amorphous Indium Gallium Zinc Oxide Thin Film Transistors Using Nitrocellulose Passivation Layer

In this research, nitrocellulose is proposed as a new material for the passivation layers of amorphous indium gallium zinc oxide thin film transistors (a-IGZO TFTs). The a-IGZO TFTs with nitrocellulose passivation layers (NC-PVLs) demonstrate improved electrical characteristics and stability. The a-IGZO TFTs with NC-PVLs exhibit improvements in field-effect mobility (μ_FE) from 11.72 ± 1.14 to 20.68 ± 1.94 cm²/(V s), threshold voltage (V_th) from 1.85 ± 1.19 to 0.56 ± 0.35 V, and on/off current ratio (I_on/off) from (5.31 ± 2.19) × 10⁷ to (4.79 ± 1.54) × 10⁸ compared to a-IGZO TFTs without PVLs, respectively. The V_th shifts of a-IGZO TFTs without PVLs, with poly(methyl methacrylate) (PMMA) PVLs, and with NC-PVLs under positive bias stress (PBS) test for 10,000 s represented 5.08, 3.94, and 2.35 V, respectively. These improvements were induced by nitrogen diffusion from NC-PVLs to a-IGZO TFTs. The lone-pair electrons of diffused nitrogen attract weakly bonded oxygen serving as defect sites in a-IGZO TFTs. Consequently, the electrical characteristics are improved by an increase of carrier concentration in a-IGZO TFTs, and a decrease of defects in the back channel layer. Also, NC-PVLs have an excellent property as a barrier against ambient gases. Therefore, the NC-PVL is a promising passivation layer for next-generation display devices that simultaneously can improve electrical characteristics and stability against ambient gases.

Comparative study of postoperative stability between conventional orthognathic surgery and a surgery-first orthognathic approach after bilateral sagittal split ramus osteotomy for skeletal class III correction

Objectives

The purpose of this study is to compare the postoperative stability of conventional orthognathic surgery to a surgery-first orthognathic approach after bilateral sagittal split ramus osteotomy (BSSRO).

Materials and Methods

The study included 20 patients who underwent BSSRO for skeletal class III conventional orthognathic surgery and 20 patients who underwent a surgery-first orthognathic approach. Serial lateral cephalograms were analyzed to identify skeletal changes before surgery (T0), immediately after surgery (T1), and after surgery (T2, after 1 year or at debonding).

Results

The amount of relapse of the mandible in the conventional orthognathic surgery group from T1 to T2 was 2.23±0.92 mm (P<0.01) forward movement and −0.87±0.57 mm (non-significant, NS) upward movement on the basis of point B and 2.54±1.37 mm (P<0.01) forward movement and −1.18±0.79 mm (NS) upward movement on the basis of the pogonion (Pog) point. The relapse amount of the mandible in the surgery-first orthognathic approach group from T1 to T2 was 3.49±1.71 mm (P<0.01) forward movement and −1.78±0.81 mm (P<0.01) upward movement on the basis of the point B and 4.11±1.93 mm (P<0.01) forward movement and −2.40±0.98 mm (P<0.01) upward movement on the basis of the Pog.

Conclusion

The greater horizontal and vertical relapse may appear because of counter-clockwise rotation of the mandible in surgery-first orthognathic approach. Therefore, careful planning and skeletal stability should be considered in orthognathic surgery.

Electric Field-aided Selective Activation for Indium-Gallium-Zinc-Oxide Thin Film Transistors

A new technique is proposed for the activation of low temperature amorphous InGaZnO thin film transistor (a-IGZO TFT) backplanes through application of a bias voltage and annealing at 130 °C simultaneously. In this ‘electrical activation’, the effects of annealing under bias are selectively focused in the channel region. Therefore, electrical activation can be an effective method for lower backplane processing temperatures from 280 °C to 130 °C. Devices fabricated with this method exhibit equivalent electrical properties to those of conventionally-fabricated samples. These results are analyzed electrically and thermodynamically using infrared microthermography. Various bias voltages are applied to the gate, source, and drain electrodes while samples are annealed at 130 °C for 1 hour. Without conventional high temperature annealing or electrical activation, current-voltage curves do not show transfer characteristics. However, electrically activated a-IGZO TFTs show superior electrical characteristics, comparable to the reference TFTs annealed at 280 °C for 1 hour. This effect is a result of the lower activation energy, and efficient transfer of electrical and thermal energy to a-IGZO TFTs. With this approach, superior low-temperature a-IGZO TFTs are fabricated successfully.

Mini-plate removal in maxillofacial trauma patients during a five-year retrospective study

OBJECTIVES

The purpose of this study was to analyze the incidence of indications for the removal of mini-plates over a five-year period in maxillofacial trauma patients.

MATERIALS AND METHODS

The medical records of 530 patients who underwent treatment with mini-plate fixation after maxillofacial trauma were reviewed for a five-year period (May 2007 to May 2012). Patients were evaluated concerning the number of mini-plates removed, age and gender distributions, time between insertion and removal, indication for removal, and site of removal.

RESULTS

The plates of 120 patients were removed (26 females and 94 males). The removal rate was 22.6%. The most frequent indication for removal was patient demand (81.7%), followed by tooth extraction (7.5%), and pain (3.3%). The most frequent removal site was the mandible (95.0%).

CONCLUSION

The number of mini-plates removed was small, and the most common indication for removal was patient demand. There is no evidence to support a recommendation for the routine removal of titanium mini-plates.

First Report of Fusarium succisae Causing Flower Rot on Thread-leaf Coreopsis

In July 2010, flower rot of thread-leaf coreopsis (Coreopsis verticillata) was found in a garden in the Icheon City, Korea. The disease affected about 20 to 50% of a 100 m² area. The disease was characterized by the appearance of pinkish mycelia on the stigmata and inflorescences of flowers. In some cases, flowers failed to bloom or turned brown before opening fully. Fragments (each 5 × 5 mm) of the symptomatic tissue were surface-sterilized with 1% NaOCl for 1 min, and then rinsed twice in sterilized distilled water. The tissue pieces were placed on water agar (WA) and incubated at 25°C for 4 to 6 days. Twenty-two isolates of Fusarium species were obtained from the diseased flowers. All isolates were identified as Fusarium succisae based on their morphological characteristics on carnation leaf agar (CLA) medium and DNA sequences of the translation elongation factor 1-alpha gene (1). Macroconidia and sporodochia were sparsely produced on CLA medium. Microconidia were abundant, borne in false heads, oval or allantoid and sometimes pyriform, and measured 4.2 to 13 × 2.2 to 5.4 μm. Chlamydospores were absent. The EF-1α gene was amplified from three isolates by PCR assay and the amplification products were sequenced (2). The nucleotide sequences obtained were deposited in GenBank with accession numbers KF514658, KF514659, and KF514660. BLASTn analysis showed 99% homology with the EF-1α sequence of F. succisae NRRL13613 (GenBank Accession No. AF160291). Pathogenicity tests were conducted with inoculation of flowers on Coreopsis verticillata. Spore suspension was prepared by flooding 7-day-old cultures on potato dextrose agar with sterilized 2% (w/v) sugar solution. When the plants started to have buds, the isolates were inoculated by placing one drop (20 μl) of spore suspension (1 × 10⁶ spores ml^-1) into the buds. Fifteen buds of the plants were arranged into three replications. The control was treated with sterilized 2% sugar solution. Inoculated plants were kept in a greenhouse at 25/20°C (12 h/12 h). Three weeks after inoculation, the symptoms were observed on buds with mycelial production. Control plants had no mycelia on buds. F. succisae was re-isolated from the inoculated flowers. To our knowledge, this is the first report of flower rot of thread-leaf coreopsis caused by F. succisae. References: (1) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Ames, IA, 2006. (2) K. O'Donnell et al. Proc. Nat. Acad. Sci. 95:2044, 1998.

Effects of Korean ginseng berry extract (GB0710) on penile erection: evidence from in vitro and in vivo studies

Several reports have promoted the root-derived Korean red ginseng (KRG; Panax ginseng) as alternative treatment for erectile dysfunction (ED), and ginsenosides are known to be the principal active ingredients of ginseng. Recent studies showed that ginseng berries produce more ginsenosides than KRG; thus, we investigated the ability of the Korean ginseng berry extract GB0710 to relax the penile corpus cavernosum smooth muscle (CCSM) in this study. As a comparative control, the results were compared to those obtained using KRG. In addition, possible mechanisms of action for GB0710 were investigated. While KRG and GB0710 both displayed dose-dependent relaxation effects on precontracted rabbit CCSM in vitro, GB0710 was shown to be more potent than KRG. The GB0710-induced relaxation could be partially reduced by removing the endothelium. In addition, pre-treatment with several nitric oxide (NO) inhibitors significantly inhibited the relaxation of muscle strips. Furthermore, administration of GB0710 increased intracavernosal pressure (ICP) in a rat in vivo model in both a dose- and duration-dependent manner. Intracellular NO production in human microvascular endothelial cells could be induced by GB0710 and inhibited by N(G)-monomethyl-L-arginine. In conclusion, GB0710 had a greater relaxation effect on rabbit CCSM than did KRG extract, and increased ICP in a rat model in both a dose- and a duration-dependent manner. This relaxing effect might be mediated by NO production.

Effects of Korean ginseng berry extract on sexual function in men with erectile dysfunction: a multicenter, placebo-controlled, double-blind clinical study

Ginseng is beneficial for many aspects of human physiology, including sexual function. In this study, we have evaluated the efficacy and safety of an extract of ginseng berry, which has a ginsenoside profile distinct from other parts of the plant, on sexual function in men with erectile dysfunction. In all, 119 men with mild-to-moderate ED participated in a multicenter, randomized, double-blind, parallel, placebo-controlled clinical study. They were administered 4 tablets of either standardized Korean ginseng berry (SKGB, 350 mg ginseng berry extract per tablet), or placebo, daily, for 8 weeks. Efficacy was assessed with the International Index of Erectile Function (IIEF)-15 and premature ejaculation diagnostic tool (PEDT) at the end of the 4th and 8th week. We observed that the total and each of the individual domain scores of IIEF-15 increased from 40.95 ± 7.05 to 46.19 ± 12.69 significantly in the SKGB by the 8th week (P<0.05). The erectile function domain of IIEF changed slightly from 17.17 ± 2.57 to 18.59 ± 5.99 in the SKGB group by the 8th week (P<0.05). In addition, PEDT scores significantly improved from 9.14 ± 4.57 to 7.97 ± 4.4 and 7.53 ± 4.26 in the SKGB group after 4 and 8 weeks of treatment (P<0.05). Safety markers including hormone and lipid in the blood were assessed at the end of the 4th and 8th week and they remained unchanged. Oral administration of the SKGB extract improved all domains of sexual function. It can be used as an alternative medicine to improve sexual life in men with sexual dysfunction.

Basal STAT3 activities are negatively correlated with tumor size in papillary thyroid carcinomas

BACKGROUNDS

Signal transducer and activators of transcription-3 (STAT3) plays a critical role in promoting survival and cell growth as well as facilitating angiogenesis and metastasis in several cancers.

AIM

This investigation focused on evaluation of STAT3 activities in human papillary thyroid cancers (PTC).

METHODS

STAT3 activities of nuclear extracts of tumor tissue were measured from 35 PTC patients using enzyme- linked immunosorbent assay-based kits.

RESULTS

STAT3 activities of PTC tissues were significantly lower than those of surrounding normal thyroid tissues [0.36 (interquartile range 0.24-0.72) vs 0.50 (0.29-1.11) arbitrary units, p<0.01]. We further analyzed the association between STAT3 activity and clinicopathologic factors in PTC tissue. Tumors with size ≥2 cm displayed significantly lower STAT3 activities than those <2 cm [0.25 (0.21-0.37) vs 0.53 (0.37-0.61) arbitrary units, p<0.01]. Notably, tumor size was inversely correlated with STAT3 activities in T1799A BRAF mutation-positive cases (Rs=-0.58, p<0.05), but not mutation-negative cases.

CONCLUSIONS

STAT3 activities of PTC measured via DNA binding are suppressed in contrast to other human cancers. Tumor size larger than 2 cm is the only clinicopathologic parameter associated with low STAT3 activity. Moreover, tumor size appears inversely correlated with STAT3 activity, specifically in T1799A BRAF mutation-positive cases.

First Report of Internal Fruit Rot of Sweet Pepper in Korea Caused by Fusarium lactis

In June 2010, an internal fruit rot of sweet pepper (Capsicum annuum L.) fruit was found in a commercial greenhouse in Ilsan City, Korea. Disease incidence reached approximately 5% of 30 tons of harvested peppers. Affected fruits commonly did not show external symptoms. However, when the fruit was cut open, an internal rot and pinkish gray mycelium were observed on the seeds and the inner surface of fruit. Discolored soft patches, browning, and necrosis were observed on the outer surface of some fruits. Fragments (5 × 5 mm²) of the affected tissues were surface sterilized with 1% NaOCl for 30 s and then rinsed twice in sterile distilled water. The pieces were placed on water agar and incubated at 25°C for 4 to 6 days. Twenty-nine Fusarium isolates were obtained from 12 diseased fruits and maintained on synthetic low nutrient agar (SNA) at 10°C. The isolates were cultured on carnation leaf agar (CLA) and SNA at 23°C with 12 h of near-ultraviolet light per day for 14 days. Microconidia were abundant, borne in short, zig-zag chains or false heads, obovoid or clavate with a flattened base, and measured 4.3 to 7.1 × 2.2 to 3.3 μm. Macroconidia were sparse, thin walled, slender, straight to slightly curved, and measured 32 to 48 × 2.8 to 3.9 μm. Sporodochia were rare on CLA and chlamydospores were absent. The translation elongation factor 1-alpha (EF-1α) gene was amplified from four isolates (SPF01, SPF09, SPF16, and SPF22) by PCR assay using ef1 and ef2 primers (2), and the 700-bp amplification products were sequenced. The nucleotide sequences were deposited in GenBank (Accession Nos. JF411956 to JF411959). BLAST analysis showed 98% homology with the EF-1α sequence of Fusarium lactis NRRL25200 (GenBank Accession No. AF160272). All isolates were identified as F. lactis based on morphological and molecular characteristics (1). Pathogenicity tests of the four isolates were conducted by inoculating flowers on plants of the orange pepper cv. Orange Glory (3). A spore suspension was prepared by flooding 5-day-old cultures on potato dextrose agar with sterile distilled water. When the plants started to flower, each flower was inoculated by placing 20 μl of spore suspension (1 × 10⁶ conidia/ml) on each flower. Four isolates of F. lactis were each inoculated onto three flowers on each of seven plants. Flowers from the same number of plants inoculated with sterile distilled water were used as the control treatment. Inoculated plants were kept in a greenhouse at 25°C by day and 20°C by night. Sixty days after inoculation, mature fruits were harvested and cut open to check for internal rot. Approximately 70% of inoculated fruits showed internal rot and pinkish gray mycelial growth on the inner surface of the fruits. No symptoms were observed on the control fruits. Fungal cultures resembling F. lactis were reisolated from inoculated fruits for all four isolates, fulfilling Koch's postulates. F. lactis has been reported on sweet pepper in the Netherlands and Canada (3). To our knowledge, this is the first report of internal fruit rot of sweet pepper caused by F. lactis in Korea. Although disease severity was low in this greenhouse, the economic impact on sweet pepper could be significant because the disease can reduce the quality, quantity, and market value of pepper fruits. References: (1) H. I. Nirenberg and K. O'Donnell. Mycologia 90:434, 1998. (2) K. O'Donnell et al. Proc. Natl. Acad. Sci. USA 95:2044, 1998. (3) J. Yang et al. Can. J. Plant Pathol. 31:47, 2009.

Nanotubular oxide surface and layer formed on the Ti-35Ta-xZr alloys for biomaterials

Titanium and its alloys are widely used as a dental implant material in clinical dentistry and as an orthopedic implant materials due to their good mechanical properties, corrosion resistance, and biocompatibility. In this study, nanotubular oxide surface and layer formed on the Ti-35Ta-xZr alloys for biomaterials have been investigated by using electrochemical methods. Ti-35Ta-xZr alloys were prepared by arc melting and heat treated for 24 hr at 1000 degrees C in argon atmosphere, and then water quenching. Ti oxide nanotubes were formed on the Ti-35Ta-xZr alloys by anodizing in H3PO4 containing 0.8 wt% NaF solution at 25 degrees C. Anodization was carried out using a scanning potentiostat. Microstructures of the alloys and nanotube surface were examined by FE-SEM, EDX, and XRD. Crystallization treatment of nanotube surface was carried out for 3 hr at 450 degrees C. Microstructures of the Ti-35Ta-xZr alloys were changed from beta phase to alpha'' phase, and changed from an equiaxed to a needle-like structure with increasing Zr content. Nanotubular oxide surface and layers consisting of highly ordered nanotubes with a wide range of diameters (approximately 150-200 nm) and lengths (approximately 4-10 microm) can be formed on alloys in the Ti-35Ta-xZr alloys with Zr content. As the Zr content increased from 3% to 15%, length of step between the bamboo knob-like had increasing values of approximately 50 nm, 80 nm, and 140 nm, respectively. The nanotubes formed on the Ti-35Ta-xZr alloy surface were amorphous structure before heat treatment, but oxide surface had mainly an anatase structure by heat treatment.

Electrochemical behavior of nano and femtosecond laser textured titanium alloy for implant surface modification

In this study, the electrochemical behavior of nano and femtosecond laser textured titanium alloy for implant surface modification has been researched using the potentiostat equipment. Cp-Ti and Ti-6Al-4V alloy, located on X-Y motorized stage, were irradiated using femtosecond laser. The corrosion properties were examined by a potentiodynamic and AC impedance test.

A New Disease, Bacterial Leaf Spot of Rape, Caused by Atypical Pseudomonas viridiflava in South Korea

In March 2007, a bacterial leaf spot of rape (Brassica napus var. oleifera) was observed in fields near Seogwipo City, Jeju Province, South Korea. Symptoms on leaves included white and corky-brown spots and sometimes water-soaked spots on the lower leaf surface. Seven bacterial isolates (BC2495-BC2497 and BC2506-BC2509) were recovered on trypticase soy agar (TSA) from leaf spot lesions surface sterilized in 70% ethyl alcohol for 1 min. Isolates were gram-negative, aerobic rods with one to three flagella. Pathogenicity was evaluated on 2-week-old rape plants by spot and spray inoculation. Bacteria were grown on TSA for 48 h at 25°C. Five microliters of bacterial suspension in sterile distilled water (1 × 10⁵ CFU/ml) were spot inoculated on pinpricked positions of five detached leaves for each isolate. The detached leaves were incubated in a plastic box with high humidity at 20°C. Spot-inoculated surfaces turned white 48 h after inoculation followed by a brownish discoloration. A bacterial suspension in sterile distilled water (100 ml at 1 × 10⁵ CFU/ml) was sprayed onto three plants for each isolate. Plants were maintained in a growth chamber at 20°C and 90% relative humidity. Isolates induced identical symptoms 2 weeks after spray inoculation as those originally observed on rape in the fields. Bacteria were reisolated 18 days after inoculation from diseased lesions surface sterilized in 70% ethyl alcohol for 1 min. Pathogenicity of the reisolated bacteria was confirmed by spot inoculation as described above. No symptoms were noted on detached leaves and intact plants inoculated with sterilized distilled water. Using the Biolog Microbial Identification System, Version 4.2 (Biolog Inc., Hayward, CA), the isolates were identified as Pseudomonas viridiflava with a Biolog similarity index range of 0.52 to 0.72 after 24 h. Results of LOPAT tests (2) of isolates were identical to that of atypical P. viridiflava reported by Gonzalez et al. (1). Levan production and pectolytic activity of the isolates were variable. All isolates were positive for tobacco hypersensitivity and negative for oxidase reaction and arginine dihydrolase production. The 16S rDNA region (1,442 bp) of the isolates (GenBank Accession Nos. HM190218-HM190224; P. viridiflava CFBP2107^T = HM190229), amplified by using universal PCR primers, shared 100% sequence identity with atypical P. viridiflava (GenBank Accession No. AM182934) (1). The gyrB sequence (638 bp) from the isolates (GenBank Accession Nos. HM190232-HM190238; P. viridiflava CFBP2107^T = HM190239), amplified by using previously reported PCR primers (3), had a distance index value range of 0.029 to 0.031 with that of the P. viridiflava CFBP2107^T (=BC2597) as determined by Jukes-Cantor model using MEGA Version 4.1 (4). On the basis of phenotypic characteristics and the sequences, the seven isolates were identified as atypical P. viridiflava. The disease is named "bacterial leaf spot". To our knowledge, this is the first report of bacterial leaf spot of rape caused by atypical P. viridiflava. References: (1) A. J. Gonzalez et al. Appl. Environ. Microbiol. 69:2936, 2003. (2) R. A. Lelliott et al. J. Appl. Bacteriol. 29:470, 1966. (3) H. Sawada et al. J. Mol. Evol. 49:627, 1999. (4) K. Tamura et al. Mol. Biol. Evol. 24:1596, 2007.

Wildfire of Soybean Caused by Pseudomonas syringae pv. tabaci, a New Disease in Korea

In 2006 and 2007, a new bacterial disease was observed in field-cultivated soybeans in Boeun District and Munkyung City of Korea. The disease caused severe blighting of soybean (Glycine max) leaves. Soybean leaves in fields showed yellowish spots with brown centers. Brown and dead areas of variable size and shape were surrounded by wide, yellow haloes with distinct margins. Spots might coalesce and affected leaves fell readily. Seven bacterial strains were isolated from chlorotic areas of soybean leaves and all produced white colonies on trypticase soy agar. With the Biolog Microbial Identification System, version 4.2, (Biolog Inc., Hayward, CA) all strains and Pseudomonas syringae pv. tabaci CFBP2106^T were identified as P. syringae pv. tabaci with a Biolog similarity index of 0.28 to 0.52 and 0.48 after 24 h. Pathogenicity of the strains (three plants per strain) on soybean leaves at the V5 stage (cv. Hwanggeum) was confirmed by rub inoculation with bacterial suspensions (1 × 10⁸ CFU/ml) in sterile distilled water on the lesions cut 1 cm long on the upper side of the leaves with razor blades and by pinprick on 3-week-old leaves of tobacco (Nicotiana tabacum cv. Samsun) in the greenhouse. Wildfire symptoms on the soybean leaves and faint halos on tobacco leaves were observed 4 days after inoculation. The identification of reisolated bacterial strains was confirmed with the metabolic fingerprintings on Biolog. LOPAT tests (1) and phenotypic characteristics (3) of the strains were similar to those of the CFBP2106^T. Colonies were levan positive, oxidase negative, potato soft rot negative, arginine dihydrase negative, and tobacco hypersensitivity negative. All strains were gram-negative, aerobic rods with a polar flagellum. Strains were negative for esculin hydrolysis, gelatin liquefaction, urea production, accumulation of poly-β-hydroxy butyrate, starch hydrolysis, ornithine dihydrolase, lysine dihydrolase, growth at 37°C, utilization of geraniol, benzoate, cellobiose, sorbitol, trehalose, l-rhamnose, and adonitol. Positive reactions were catalase and arbutin hydrolysis, utilization of sorbitol, d-arabinose, and dl-serine. The strains were variable in utilization of mannitol, sucrose, and d-arabinose. The 1,472-bp PCR fragments of strains, BC2366 (GenBank Accession No. FJ755788) and BC2367 (No. FJ755789) was sequenced using 16S rDNA universal primers (2). The sequences shared 100% identity with the analogous sequences of P. syringae pv. glycenea (GenBank Accession No. AB001443) available in NCBI databases. Based on the phenotypic, genetic, and pathological characteristics, all strains were identified as P. syringae pv. tabaci. To our knowledge, this is the first report of P. syringae pv. tabaci causing wildfire on soybean in Korea. References: (1) R. A. Lelliott et al. J. Appl. Bacteriol. 29:470, 1966. (2) I.-S. Myung et al. Plant Dis. 92:1472, 2008. (3) N. W. Schaad et al., eds. Laboratory Guide for Identification of Plant Pathogenic Bacteria. 3rd ed. The American Phytopathological Society, St. Paul, MN, 2001.

Effects of oral epigallocatechin gallate supplementation on the minimal erythema dose and UV-induced skin damage

BACKGROUND/AIMS

Excessive exposure to UV radiation causes acute adverse effects like sunburn and photosensitivity reactions and is involved in the induction and development of skin cancer. It has been reported that antioxidants have photoprotective effects against solar UV radiation. We investigated the effect of oral epigallocatechin gallate (EGCG), a powerful antioxidant in green tea, on the minimal erythema dose (MED) and UV-induced skin damage.

METHOD

Female HWY/Slc hairless rats were fed the normal diet supplemented with 1,500 ppm EGCG for 8 weeks; then, the MED was determined and visual scores and transepidermal water loss were assessed to evaluate the severity of UV-induced skin damage.

RESULTS

At week 8 of the study, the use of dietary EGCG significantly increased MED. UV-radiation-induced sunburn severity and alterations in epidermal barrier function were also attenuated by the supplementation of EGCG.

CONCLUSION

Regular intake of EGCG strengthens the skin's tolerance by increasing MED and thus prevents UV-induced perturbation of epidermal barrier function and skin damage. These results suggest that EGCG is a potent candidate for systemic photoprotection.

First Report of Bacterial Canker of Tomato Caused by Clavibacter michiganensis subsp. michiganensis in Korea

In 2007, a new bacterial disease was observed in greenhouse-cultivated cherry tomatoes in Cheorwon and Iksan provinces, Korea. The disease caused severe wilt of tomatoes (Solanum lycopersicum cv. Koko). Infected young petioles were curled downward. Margins of the leaves rolled upward and whole leaves were distorted. Stem cankers had reddish or dark brown cavities. Vascular tissues in stems cut longitudinally were brown to deep brown, but no bird's eye lesions were observed. Eight bacterial strains recovered from the stems of wilted tomatoes produced yellow colonies on nutrient broth-yeast extract agar and pink colonies on triphenyl tetrazolium chloride. Pathogenicity of the strains (three plants per strain) on 18-day-old tomatoes (cv. Koko) was confirmed by clip inoculation of petioles of second leaves and spray inoculation with bacterial suspensions (1 × 10⁸ CFU/ml) in sterile distilled water. Wilt and canker symptoms were observed 2 weeks after inoculation. Symptoms produced by both inoculation methods were systemic and localized. Clip inoculation of tomatoes resulted in wilt, defoliation, and open stem cankers, whereas small, white spots (2 to 3 mm in diameter) and sometimes water-soaked, dark brown-to-black lesions on the leaf margins were observed with spray inoculation. Bacteria were reisolated from stems and leaves of the inoculated plants and their identities confirmed by direct PCR using specific primer set CMM5/CMM6 (1). No symptoms were observed on negative control plants inoculated with sterile water. All strains were gram-positive aerobic rods with no polar flagella. Strains were positive for esculin hydrolysis, gelatin liquefaction, H₂S production from peptone, utilization of citrate and succinate, and acid from d(+)mannose and negative for starch hydrolysis, casein hydrolysis, methyl red reaction, acid from inulin, mannitol, d(+)-melezitose and d(-)sobitol, and utilization of acetate, formate, lactate, propionate, and ribose. Identification as C. michiganensis subsp. michiganensis was confirmed using 16S rDNA universal primers fD1 and rP2 (4) and internal primers (3). The 1,439-bp PCR fragment of strain BC2643 was sequenced (GenBank Accession No. EU685335) and compared with reference C. michiganensis subspecies strains in GenBank: AM410696 (C. michiganensis subsp. michiganensis), AM410693 (C. michiganensis subsp. tessellarius), AM410697 (C. michiganensis subsp. nebraskensis), AM410694 (C. michiganensis subsp. sepedonicus), and AM410695 (C. michiganensis subsp. insidiosus). The sequence had a similarity index of 0.999 calculated by Juke-Cantor model (2) with the 16S rRNA sequence of C. michiganensis subsp. michiganensis (AM410696). The fragment size of eight strains amplified by PCR using CMM5/CMM6 (1) was identical to that of the C. michiganensis subsp. michiganensis reference strain KACC20122. On the basis of the physiological, genetic, and pathological characteristics, all strains were identified as C. michiganensis subsp. michiganenesis. To our knowledge, this is the first report of C. michiganensis subsp. michiganenesis causing bacterial canker on tomato in Korea. References: (1) J. A. Dreier et al. Phytopathology 85:464, 1995. (2) S. Kumar et al. Brief. Bioinform. 5:50, 2004. (3) S. W. Kwon et al. Int. J. Syst. Bacteriol. 47:1061, 1997. (4) W. G. Weinsburg et al. J. Bacteriol. 173, 697, 1991.

Histopathologic changes of acellularized xenogenic carotid vascular grafts implanted in a pig-to-goat model

INTRODUCTION

The present study was designed to determine the in vivo patency and recellularization pattern of acellularized small-diameter xenogenic arterial grafts. We implanted acellularized porcine carotid arteries in bilateral carotid arteries of goats and microscopically analyzed the recellularization pattern of these grafts with the recipient's cells over time.

MATERIAL AND METHODS

Carotid arteries of pigs weighing 30-40 kg were harvested and decellularized with hypertonic saline followed by sodium dodecyl sulfate. Acellularized porcine carotid vascular xenografts (0.4-0.5 cm in diameter) were prepared into 4 cm-long segments and implanted bilaterally in the carotid arteries of 10 black-haired goats. The in vivo patency of the implanted acellularized xenogenic grafts was evaluated at regular intervals by color Doppler ultrasonography. The goats were sacrificed at predetermined intervals (1 week, 1 month, 3 months, 6 months, 12 months after implantation), two animals at each interval. Upon retrieval, visual inspections and histopathologic examinations of the grafts were performed. To identify smooth muscle cells and functioning endothelial cells, immunohistochemical staining for alpha-smooth muscle actin and von Willebrand factor were also performed.

RESULTS AND CONCLUSIONS

All experimental animals survived the observation period. Nineteen out of 20 implanted grafts showed patency with no thrombi. Microscopic analysis revealed that the grafts were completely covered with the hosts' endothelial cells, beginning from anastomotic sites. The grafts were gradually recellularized with recipients'cells including fibroblasts, myofibroblasts and smooth muscle cells. In conclusion, this study suggested that acellularized xenogenic vascular grafts can be a good alternative for the small-diameter vascular graft.

Biological control agent of common scab disease by antagonistic strain Bacillus sp. sunhua

AIMS

To identify an antagonistic strain against Streptomyces scabiei and to characterize the antibiotic agent. The efficacy of the isolated strain in controlling common scab disease was also evaluated.

METHODS AND RESULTS

A bacterial strain antagonistic against S. scabiei was isolated from the soil of a potato-cultivating area. This bacterium was identified as a Bacillus species by 16S rRNA gene sequence analysis and was designated Bacillus sp. sunhua. Antibiotics produced by this strain were proven to be stable within a broad pH range and at high temperatures. The culture broth was extracted with ethyl acetate, and then the crude extract was applied to HPLC. Two compounds were isolated and identified as iturin A and macrolactin A by 1H-NMR, 13C-NMR, HMBC, HMQC and mass spectrometer. The culture broth of Bacillus sp. sunhua had a suppressive effect on common scab disease in a pot assay, decreasing the infection rate from 75 to 35%. This strain also suppressed Fusarium oxysporum, the pathogen of potato dry rot disease.

CONCLUSIONS

Bacillus sp. sunhua was shown to inhibit S. scabiei effectively.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report demonstrating that macrolactin A and iturin A inhibit S. scabiei. This study demonstrated the possibility of controlling potato scab disease using Bacillus sp. sunhua.

Home Care Artificial Heart Monitoring System via Internet

The availability of a remote management system, which provides both physiological-related information about the patient and device-related information about the implanted device, would be helpful during in vivo experiments or clinical trials involving artificial heart implantation. In order to be able to monitor the course of the in vivo experiment continuously regardless of the patient's location, an internet-based remote monitoring system was developed, which can monitor physiological-related information such as pressure (AoP, LAP, RAP, PAP) and flow data, as well as device-related information such as current, direction and pump operating conditions. The home care artificial heart monitoring system which we developed consists of four main components, which are the transcutaneous information transmission system (TITS), local monitoring station (LMS), data server station (DSS), and client monitoring station (CMS). The device-related information and physiological-related information can be transmitted in real time from a patient in a remote non-clinical environment to the specialist situated in a clinic depending on the current capabilities and availability of the internet. The local monitoring station situated at the remote site is composed of a data acquisition and preprocessing unit connected to a computer via its RS-232 port, and which communicate using a Java-based client-server architecture. The remote monitoring system so developed was used during an in vivo experiment of the artificial heart implantation for 2 months and performed successfully according to design specifications.

A chronic heart failure model by coronary artery ligation in the goat

The availability of a reliable heart failure model in large animals is important. We report upon our efforts to develop a chronic heart failure model in seven goats using sequential ligation of the left anterior descending (LAD) coronary artery and its diagonal branch. After anesthesia and left thoracotomy, the LAD artery was ligated, and the diagonal vessel at the same level was ligated one hour later. Cardiac measurements were performed with a thermodilution catheter and by ultrasonography. Two months after the operation, the same measurements were made and animals were sacrificed for postmortem examinations of their hearts. Hemodynamic measurements, except cardiac output, showed no significant changes immediately after the coronary artery ligation. Echocardiographic measurements showed significant changes in the ejection fraction and fractional shortening without changes in left ventricular dimensions. Wall motion analyses demonstrated variable degrees of anteroseptal dyskinesia and akinesia in all animals immediately after coronary artery ligation. Five animals have undergone hemodynamic and ultrasonographic studies 2 months after coronary artery ligation. The results obtained from these animals showed significant increases in central venous pressure, right ventricular pressure, pulmonary artery pressure, and pulmonary artery capillary wedge pressure, and a significant decrease in cardiac output. Increases in left ventricular dimensions and decreases in ejection fraction with fractional shortening in ultrasonographic studies were also observed. Pathologically, well-demarcated thin-walled anteroseptal infarcts, with chamber enlargement, were clearly seen with dilatation of the heart chambers in all specimens. Based on this study, we conclude that goats, like sheep, can provide a reliable model of chronic heart failure by coronary artery ligation and in view of the many advantages offered by goats, we believe that this animal model will be useful for cardiac experimentation.

AnyHeart: a single-piece heart-saving implantable artificial heart (BVAD)--monitoring and estimation

AnyHeart is a single-piece, implantable biventricular assist device. This electromechanical BVAD has a moving-actuator mechanism. To monitor the status of AnyHeart from anywhere at any time, a portable personal digital assistant (PDA) monitor and web-based remote monitoring system were developed. The PDA local monitoring system has replaced bulky personal computer monitoring systems. The web-based remote monitoring system has several functions such as data collecting, storing, and posting through the internet. Basically, interventricular pressure (IVP) is a parameter indicating the filling level of the blood chambers of AnyHeart. The pump output can be estimated using IVP, which is acquired noninvasively from AnyHeart. With the proposed method, we can estimate the pump output with a small margin of error.

Autologous cardiomyocyte transplantation using a biodegradable polymer scaffold

BACKGROUND

To achieve a more reliable way of transplanting cardiomyocytes, we conducted an autologous cardiomyocyte transplantation using a biodegradable scaffold, instead of a syringe injection, as a vehicle for transporting cells in an ovine myocardial infarction model.

MATERIALS AND METHODS

A myocardial infarction was created in sheep using sequential ligation of the homonymous artery and its diagonal branch. Autologous cardiomyocytes from the right ventricular infundibulum were cultured and seeded onto a biodegradable polymer scaffold. Three months after creating myocardial infarction, the two animals were re-anesthetized and cardiomyocyte-seeded scaffolds were implanted in the infarcted area. The animals were kept alive for a further month, and then sacrificed for postmortem heart examinations. Light microscopic analysis and an immunohistochemical study for myoglobin were performed.

RESULTS

On postmortem gross examinations, the polymer scaffolds were visible in the background of well-demarcated thin-walled anteroseptal myocardial infarcts. Microscopic analysis showed abundant myoglobin-stained cells between the fiber strands of the polymer scaffolds. However, there is a possibility that some of these cells might have been giant cells reacting to foreign material.

CONCLUSION

The transplantation of cultured autologous cardiomyocytes into an infarct region using a biodegradable scaffold instead of syringe injection provides another promising option for cardiomyocyte transplantation, which warrants further study.

Comparison of myocardial infarction with sequential ligation of the left anterior descending artery and its diagonal branch in dogs and sheep

We report a comparison of the effects of myocardial infarction in dogs and sheep using sequential ligation of the left anterior descending artery (LAD) and its diagonal branch (DA), with hemodynamic, ultrasonographic and pathological evaluations. Five animals were used in each group. After surgical preparation, the LAD was ligated at a point approximately 40% of the distance from the apex to the base of the heart, and after one hour, the DA was ligated at the same level. Hemodynamic and ultrasonographic measurements were performed preligation, 30 minutes after LAD ligation, and 1 hour after DA ligation. As a control, two animals in each group were used for the simultaneous ligation of the LAD and the DA. Two months after the coronary ligation, the animals were evaluated as previously, and killed for postmortem examination of their hearts. All seven animals in the dog group survived the experimental procedures, while in the sheep group only animals with sequential ligation of the LAD and DA survived. Statistically significant decreases in systemic arterial blood pressure and cardiac output, and an increase in the pulmonary artery capillary wedge pressure (PACWP) were observed one hour after sequential ligation of the LAD and its DA in the sheep, while only systemic arterial pressures decreased in the dog. Ultrasonographic analyses demonstrated variable degrees of anteroseptal dyskinesia and akinesia in all sheep, but in no dogs. Data two months after coronary artery ligation showed significant increases in central venous pressure, pulmonary artery pressure, and PACWP in the sheep, but not in the dog. Left ventricular end-diastolic dimension and left ventricular end-systolic dimension in ultrasonographic studies were also increased only in the sheep. Pathologically, the well-demarcated thin-walled transmural anteroseptal infarcts with chamber enlargement were clearly seen in all specimens of sheep, and only-mild-to-moderate chamber enlargements with endocardial fibrosis were observed in the dog hearts. In conclusion, this study confirms that the dog is not a suitable model for myocardial infarction with failure by coronary artery ligation despite negligent operative mortality, when compared directly with an ovine model.

Tissue-engineered heart valve leaflets: an effective method of obtaining acellularized valve xenografts

To determine the most effective method of producing the acellularized xenograft heart valve leaflets, we compared pathological findings of the xenograft heart valve leaflets produced by three methods; freeze-thawing, Triton and NaCl-SDS treatment and further analyzed the pattern of endothelial cells seeded onto them.

MATERIALS AND METHODS

Two pigs were sacrificed and three pulmonary valve leaflets were harvested from each animal. They were immediately stored in a tissue preservation solution and assigned in one of the three preparation methods for acellularization. Endothelial cells from the jugular vein of a goat were isolated and seeded onto the acellularized xenograft heart valve leaflets. Light and Electron microscopic analyses were performed.

RESULT AND CONCLUSION

H & E stain showed that cells were almost absent in the leaflet treated with NaCl-SDS, while cells were partly present in the leaflets treated, one with Triton and the other Freeze-thawing. Transmission microscopic analyses showed cell-free matrix with well preserved collagen architecture under the seeded endothelial cells in the leaflets treated with NaCl-SDS. In conclusion, the valve leaflets treated with NaCl-SDS among three representative methods of acellularization of tissues (freeze-thawing, Triton X-100, and NaCl-SDS) showed the better results than the others in terms of the efficacy of decellularization and response to endothelial cell seeding.

Competitive adsorption for binary mixture of 4-nitrophenol and phenol on RSTA using GAC

Adsorption characteristics of a reverse stratified tapered adsorber (RSTA) system and competitive adsorption for phenol and 4-nitrophenol were investigated. In this study, a novel technology, RSTA, was introduced and compared with a conventional cylindrical adsorber (CA). The optimum study of RSTA in a single-solute system with phenol for size distribution, mean velocity and optimum angle was conducted to satisfy environmental criteria and reduce granular activated carbon (GAC) treatment costs. The competitive adsorption efficiency of RSTA and CA was also compared in a binary solute system with phenol and 4-nitrophenol. In the results of single-solute experiment, breakthrough time of RSTA was increased by 30-50% over conventional CA. The mean bed velocity was 19.10 cm/min and the optimum angle of RSTA was decided to 3 degrees. Adsorption efficiency was increased with increasing GAC dose and the number of GAC layers. The affinity of competitive adsorption was significantly increased with decreasing GAC dose and increasing adsorbate concentration. The RSTA can be considered to provide an increase in breakthrough time with decreasing flow rate and increasing the number of layers. Water and wastewater plants processing large volumes of water can realize significant savings in capital and operation costs by utilizing this type of operation.

Application of the moving-actuator type pump as a ventricular assist device: in vitro and in vivo studies

A moving actuator type pump has been developed as a multifunctional Korean artificial heart (AnyHeart). The pump consists of a moving actuator as an energy converter, right and left sacs, polymer (or mechanical) valves, and a rigid polyurethane housing. The actuator containing a brushless DC motor moves back and forth on an epicyclical gear train to produce a pendular motion, which compresses both sacs alternately. Of its versatile functions of ventricular assist device and total artificial heart use, we have evaluated the system performance as a single or biventricular assist device through in vitro and in vivo experiments. Pump performance and anatomical feasibility were tested using various animals of different sizes. In the case of single ventricular assist device (VAD) use, one of the sacs remained empty and a mini-compliance chamber was attached to either an outflow or inflow port of the unused sac. The in vitro and in vivo studies show acceptable performance and pump behavior. Further extensive study is required to proceed to human application.

A simplified cardiopulmonary bypass technique for animal experiments on implantable ventricular assist devices

We have developed and report on a simplified cardiopulmonary bypass technique for experiments on implantable ventricular assist devices in calves. We used an electromechanical implantable ventricular assist device with a double cylindrical cam in three calves. Cannulas for the ventricular assist system were designed to be inserted between the left atrium and the descending aorta. We used the outflow cannula of the ventricular assist device, anastomosed to the descending aorta, as a temporary arterial return route for the cardiopulmonary bypass. A cannula for venous drainage was iserted into the right ventricle through the pulmonary artery. There were no problems related to the procedure and the cardiopulmonary bypass was succesful. In conclusion, this simplified cardiopulmonary bypass technique without neck incision in calves, as used in developmental work involving implantable ventricular assist devices, can be reliably performed.

Autologous cardiomyocyte transplantation in an ovine myocardial infarction model

BACKGROUND

To evaluate the possibility of autologous cardiomyocyte transplantation, we transplanted cultured autologous cells into an infarct region developed by coronary artery ligation in an ovine model.

MATERIALS AND METHODS

A chronic heart failure model with a considerable portion of myocardial infarction was created in sheep using sequential ligation of the homonymous artery and its diagonal branch. Autologous cardiomyocytes were cultured and isolated from the right ventricular infundibulum. After a predetermined interval (one animal for two months and the other for three months), the two animals were reanesthetized and a suspension of cultured autologous vetricular cells in 0.3 ml of culture medium (1.2 x 10(7) cells) was injected into the center of three out of the four sites in the infarcted area using a tuberculin syringe. The same amount of culture medium was injected with an identical procedure into the center of the remaining site, as control. The animals were kept alive for a further month, and then sacrificed for postmortem heart examinations. Light microscopic analysis and immunohistochemical study for myoglobin were done.

RESULTS AND CONCLUSIONS

On postmortem gross examination, well-demarcated thin-walled anteroseptal infarcts with chamber enlargement were clearly seen in specimens from the two animals. Microscopic analysis showed homogenous fibrosis throughout the infarcted areas. In both animals, one of the three sites of cardiomycyte injection showed an islet of cardiomyocytes in the mid-myocardium, while none were observed in the control site of either animal. A layer of cardiomyocytes was observed in subendocardial regions, as it was in the control areas. In conclusion, cardiomyocyte transplantation into the infarct regions developed by coronary artery ligation in an ovine model was achieved with only limited success. An understanding of why only 33% of cardiomyocyte-injection sites demonstrated viable cardiomyocytes, in the form of tiny cell islets, remains to be elucidated.

Chronic heart failure model with sequential ligation of the homonymous artery and its diagonal branch in the sheep

We report a reliable chronic heart failure model in sheep using sequential ligation of the homonymous artery and its diagonal branch. After a left anterior thoracotomy in Corridale sheep, the homonymous artery was ligated at a point approximately 40% of the distance from the apex to the base of the heart, and after 1 hour, the diagonal vessel was ligated at a point at the same level. Hemodynamic measurements were done preligation, 30 minutes after the homonymous artery ligation, and 1 hour after diagonal branch ligation. The electrocardiograms were obtained as needed, and cardiac function was also evaluated with ultrasonography. After a predetermined interval (2 months for five animals and 3 months for two animals), the animals were reevaluated in the same way as before, and were killed for postmortem examination of their hearts. All seven animals survived the experimental procedures. Statistically significant decreases in systemic arterial blood pressure and cardiac output and increases in pulmonary artery capillary wedge pressure were observed 1 hour after sequential ligation of the homonymous artery and its diagonal branch. Untrasonographic analyses demonstrated variable degrees of anteroseptal dyskinesia and akinesia in all animals. The data from animals at 2 months after coronary artery ligation showed significant increases in central venous pressure, pulmonary artery pressure, and pulmonary artery capillary wedge pressure. Left ventricular enddiastolic dimension and left ventricular end-systolic dimension on ultrasonographic studies were also increased. Electrocardiography showed severe ST elevation immediately after the ligation and pathologic Q waves were found at 2 months after ligation. The thin walled infarcted areas with chamber enlargement were clearly seen in the hearts removed at 2 and 3 months after ligation. In conclusion, we could achieve a reliable ovine model of chronic heart failure using a simple concept of sequential ligation of the homonymous and diagonal arteries. This animal model was comparable to the clinical situation.

Tissue-engineered heart valve leaflets: an animal study

BACKGROUND

Tissue-engineered heart valve leaflets are a promising way to overcome the inherent limitations of current prosthetic valves. The aim of this study was to compare the biological responses of an autologous cell seeded scaffold and an acellular scaffold implanted in the pulmonary valve leaflet in the same animal.

METHODS

Myofibroblasts and endothelial cells were isolated and cultured from an ovine artery. A synthetic biodegradable scaffold consisting of polyglycolic acid and polylactic acid was initially seeded with the myofibroblasts, then coated with endothelial cells. Cells were seeded using a medium containing collagen and cultured. A tissue-engineered construct and a plain scaffold were implanted as double pulmonary valve leaflet replacement in the same animal in an ovine model (n=3). Additionally, the tissue-engineered construct (n=2) and the plain scaffold (n=2) were implanted as single valve leaflet replacements for long-term analysis. After sacrifice, the implanted valve leaflet tissues were retrieved, analyzed visually and using light microscopy.

RESULTS

Three animals that underwent replacement of two valve leaflets with a tissue-engineered construct and a plain scaffold, survived only a short-time (12, 24, 36 hours). The death was attributed to heart failure caused by severe pulmonary insufficiency. Animals that underwent single valve leaflet replacement survived longer and were electively sacrificed at 6 and 9 weeks after operation. The analysis of the leaflets from the short-term survivors showed that the tissue-engineered constructs contained less fibrins and protein exudates than the plain scaffold. In contrast, leaflets obtained from animals surviving 6 and 9 weeks showed similar well organized granulation tissues in the tissue-engineered constructs and the plain scaffolds.

CONCLUSION

This animal experiment demonstrates that in the early phase of implantation, the tissue-engineered construct shows a better biological response in terms of antithrombogenicity than the plain scaffold, although both of them have similar results in the later reparative phase.

A case of disseminated Trichosporon beigelii infection in a patient with myelodysplastic syndrome after chemotherapy

Trichosporonosis is a potentially life-threatening infection with Trichosporon beigelii, the causative agent of white piedra. The systemic infection by this fungus has been most frequently described in immunocompromised hosts with neutropenia. Here, we report the first patient with disseminated infection by T. beigelii in Korea, acquired during a period of severe neutropenia after chemo-therapy for myelodysplastic syndrome. The patient recovered from the infection after an early-intensified treatment with amphotericin B and a rapid neutrophil recovery. The disseminated infection by T. beigelii is still rare, however, is an emerging fatal mycosis in immunocompromised patients with severe neutropenia.

Light and electron microscopic analyses for ischaemia-reperfusion lung injury in an ovine cardiopulmonary bypass model

An experiment to study the role of contact-activation leukocyte sequestration in the formation of ischaemia-reperfusion injury (I-R injury) was carried out. The study was conducted using light and electron microscopic analyses in an ovine cardiopulmonary bypass (CPB) model using a membrane oxygenator. Five adult sheep were used in the study. The CPB circuitry consisted of a roller pump and a membrane oxygenator. During CPB, flow rates ranged from 50 to 60 ml/kg/min with mild hypothermia. The CPB time was fixed at 120 min. Ten minutes after the start of CPB, total CPB was established. Thereafter, total CPB was performed for 100 min, followed by another 10 min of partial CPB. Lung biopsy specimens for light and electron microscopy were obtained from the upper lobe of the right lung before CPB, 109 min after the start of CPB (just before reperfusion) and 30 min after weaning (after reperfusion). A portion of the lung biopsy specimen was taken for a water content measurement at the same time intervals. For measuring the left and right atrial leukocyte counts, blood samples were taken before thoracotomy, 5 and 109 min after the start of CPB, and 30 and 120 min after weaning. C3a was measured before thoracotomy, 109 minafter the start of CPB, and 30 and 120 min after weaning. Plasma malondialdehyde (MDA) was checked before thoracotomy, 109 min after the start of CPB and 30 min after weaning. On both light and electron microscopic examination, mild to moderate acute lung change was observed after ischaemia-reperfusion. Interstitial oedema, leakage of erythrocytes into the alveolar space and endothelial cell swelling were the main findings. However, few neutrophils were seen. Water content of the lung showed a slight increase after the start of CPB, but there was no statistical significance. Neither significant differences in the transpulmonary gradients of leukocytes nor a significant complement activation, expressed by C3a levels, was observed. The MDA level did not display a significant change related to lung reperfusion despite an increase in MDA after the start of CPB. These findings indicate that I-R injury during CPB may not be from complement-activation leukocyte sequestration, but from another source of oxygen free radicals related to CPB.

Scanning electron microscopic analysis of arterial line filters used in cardiopulmonary bypass

The clinical value of arterial line filters is still a controversial issue. Proponents of arterial line filtration argue that filters remove particulate matter and undissolved gas from circulation while opponents argue the absence of conclusive clinical data. We conducted scanning electron microscope (SEM) studies of arterial line filters used clinically in the cardiopulmonary bypass circuits during adult cardiac surgery and analyzed the types and characteristics of materials entrapped in the arterial line filters. Twelve arterial line filters were obtained during routine hypothermic cardiopulmonary bypass in 12 adult cardiac patients. The arterial line filter was a screen type with a pore size of 40 microm (Baxter Health Care Corporation, Bentley Division, Irvine, CA, U.S.A. ). After opening the housing, the woven polyester strands were examined with SEM. All segments examined (120 segments, each 2.5 x 2. 5 cm) contained no embolic particles larger in their cross-sectional area than the pore size of the filter (40 microm). The origins of embolic particulates were mostly from environmental foreign bodies. This may suggest a possible need for more aggressive filtration of smaller particulates than is generally carried out at the present time.