Quantitative phase and refractive index imaging of 3D objects via optical transfer function reshaping

Deconvolution phase microscopy enables high-contrast visualization of transparent samples through reconstructions of their transmitted phases or refractive indexes. Herein, we propose a method to extend 2D deconvolution phase microscopy to thick 3D samples. The refractive index distribution of a sample can be obtained at a specific axial plane by measuring only four intensity images obtained under optimized illumination patterns. Also, the optical phase delay of a sample can be measured using different illumination patterns.

Predictors of the Effects of Flow Diversion in Very Large and Giant Aneurysms

BACKGROUND AND PURPOSE

The treatment paradigm for very large and giant aneurysms has recently changed to flow diversion, in light of the results of the Pipeline for Uncoilable or Failed Aneurysms trial. However, the effects of flow diversion were definitely unknown. We explored this topic and identified the predictors of such effects.

MATERIALS AND METHODS

We retrospectively reviewed 51 patients with unruptured aneurysms admitted to our institution for flow diversion between February 2014 and August 2019. Patients were categorized into an effect group (no filling or remnant entry) and a no-effect group (subtotal or total filling). We evaluated the aneurysm size and shape, incorporation vessel, parent artery stenosis and curvature, stagnation of contrast medium within the aneurysm, use of balloon angioplasty, and intra-aneurysm thrombus as potential predictors of the effects of flow diversion.

RESULTS

The effect group comprised 34 patients (66.7%, 34/51; no filling, 35.3%, 18/51; and remnant entry, 31.4%, 16/51). The no-effect group comprised 17 patients (33.3%, 17/51; subtotal filling, 29.4%, 15/51; and total filling, 3.9%, 2/51). An incorporation vessel and balloon angioplasty were independent risk factors for the no-effect group in multivariate logistic regression analyses (OR = 0.13 and 0.05; 95% confidence intervals, 0.02-0.62 and 0.00-0.32; P values, .021 and .004, respectively).

CONCLUSIONS

Flow diversion is effective for very large and giant aneurysms, but the outcomes require further improvement. The results of this study show that an incorporated vessel and excessive balloon angioplasty might compromise flow diversion. This finding can help improve the outcomes of flow diversion.

Convolutional neural network based proton stopping-power-ratio estimation with dual-energy CT: a feasibility study

Dual-energy computed tomography (DECT) has shown a great potential for lowering range uncertainties, which is necessary for truly leveraging the Bragg peak in proton therapy. However, analytical stopping-power-ratio (SPR) estimation methods have limitations in resolving the influence from the beam-hardening artifact, i.e. CT number variation of the same object scanned under different imaging conditions, such as different patient size and location in the field-of-view (FOV). We present a convolutional neural network (CNN)-based framework to estimate proton SPR that accounts for patient geometry variation and addresses CT number variation. The proposed framework was tested on both prostate and head-and-neck (HN) patient datasets. Simulated CT images were used in order to have a well-defined ground-truth SPR for evaluation. Two training scenarios were evaluated: training with patient CT images (ideal scenario) and training with computational phantoms (realistic scenario). For the training in ideal scenario, computational phantoms were created based on 120 kVp patient CT images using a custom-defined density and material translation curve. Then, 80 kVp and 150 kVp Sn DECT image pairs were obtained using ray-tracing simulation, and their corresponding SPR was calculated from the known density and elemental compositions. For the training in realistic scenario, computational phantoms were created based on the geometry of calibration phantoms. For both scenarios, evaluation was performed on the phantoms created from patient CT images. Compared to a conventional parametric model, U-net trained with computational phantoms (realistic scenario) reduced the SPR estimation uncertainty (95th percentile) of the prostate patient from 1.10% to 0.71%, and HN patient from 2.11% to 1.20%. With the U-net trained with patient images (ideal scenario) uncertainty values were 0.32% and 0.42% for prostate and HN patients, respectively. These results suggest that CNN has great potential to improve the accuracy of SPR estimation in proton therapy by incorporating individual patient geometry information.

The Fate of Unruptured Intracranial Vertebrobasilar Dissecting Aneurysm with Brain Stem Compression According to Different Treatment Modalities

BACKGROUND AND PURPOSE

Unruptured intracranial vertebrobasilar dissecting aneurysms with brain stem compression are difficult to treat. In the present study, the clinical and radiologic outcomes of unruptured intracranial vertebrobasilar dissecting aneurysms with brain stem compression based on different treatment modalities were evaluated.

MATERIALS AND METHODS

This study included 28 patients with unruptured intracranial vertebrobasilar dissecting aneurysms with brain stem compression treated from January 2009 to December 2017. Treatment methods were observation (n = 6), stent-assisted coil embolization (n = 9), parent artery occlusion (n = 6), and flow diversion (n = 7). The data of baseline characteristics, change of aneurysm size, retreatment rate, stroke occurrence, and alteration of the mRS score were obtained from retrospective chart review.

RESULTS

The initial size of dissecting aneurysms was largest in the flow diversion group (22.5 ± 7.7 mm), followed by parent artery occlusion (20.3 ± 8.4 mm), stent-assisted coil embolization (11.7 ± 2.2 mm), and observation (17.8 ± 5.5 mm; P = .01) groups. The reduction rate of aneurysm size was highest in the parent artery occlusion group (26.7 ± 32.1%), followed by flow diversion (14.1% ± 28.7%), stent-assisted coil embolization (-17.9 ± 30.3%), and observation (-31.5 ± 30.8%; P = .007) groups. Additional treatment was needed in the observation (4/6, 66.7%) and stent-assisted coil embolization (3/9, 33.3%; P = .017) groups. Improvement of the mRS score on follow-up was observed in the flow diversion (6/7, 85.7%) and parent artery occlusion (4/6, 66.7%) groups but not in the stent-assisted coil embolization and observation groups. A worsened mRS score was most common in the observation group (4/6, 66.7%), followed by stent-assisted coil embolization (3/9, 33.3%), parent artery occlusion (2/6, 33.3%), and flow diversion (0/7, 0%) groups.

CONCLUSIONS

When treating intracranial vertebrobasilar dissecting aneurysms with brain stem compression, parent artery occlusion and flow diversion should be considered to reduce aneurysm size and improve the mRS score.

Oligonol prevented the relapse of dextran sulfate sodium-ulcerative colitis through enhancing NRF2-mediated antioxidative defense mechanism

Repeated bouts of ulcerative colitis featured troublesome course of inflammatory bowel disease leading to fatal colitis-associated cancer, which is strongly associated with oxidative stress and sustained inflammation. Since oligonol, low molecular weighted polyphenol extracted from fruit lychee, showed antioxidative and anti-inflammatory actions, we hypothesized that oligonolcan prevent relapse of colitis. We compared oligonol with current gold standard therapeutics, sulfasalazine in preventive efficacy of relapse. First, dextran sulfate sodium (DSS)-induced colitis were made following pretreatment with oligonol, 10, 50, and 100 mg/kg for 7 days to measure therapeutic effect of oligonol and relapse model via repeated DSS administration was made following with either 50 mg/kg oligonol or 30 mg/kg sulfasalazine to explore relapse preventing action of oligonol in C57BL/6 mice. Detailed changes in colon were measured to explain molecular mechanisms. Pretreatment of 10, 50, 100 mg/kg oligonol (p.o.), significantly reduced DSS-induced colitis; total pathologic scores, colon length, and clinical symptom scores (P < 0.05). Oligonol pretreatment significantly decreased the levels of interleukin (IL)-1, IL-6, and tumor necrosis factor-α (TNF-α) as well as nuclear factor-κB (NF-κB), c-Fos, and c-Jun in affected colon tissues, but the expression of heme oxygenase-1 (HO-1) and NADH: quinone oxidoreductase-1(NQO-1) as well as total antioxidant concentration (P < 0.005) was significantly increased with oligonol. A relapse model established with repeated DSS administration led to high mortality. However, oligonol significantly ameliorated exacerbations of colitis, while sulfasalazine did not (P < 0.01). Significantly decreased expressions of cyclooxygenase-2 (COX-2), TNF-α, and macrophages inhibition were relapse preventing actions of oligonal, but significant action of oligonol relevant to relapse prevention was either significantly increased expressions of NQO-1 or significantly preserved mucin (P < 0.05). Concerted anti-inflammatory, antioxidative, and host defense enhancing actions of oligonol can be applied during maintenance therapy of IBD to prevent relapse of IBD.

ALK-positive anaplastic large-cell lymphoma with primary bone involvement: A rare case and review of the literature

Primary bone lymphoma (PBL) is an uncommon type of extranodal lymphoma involvement. An anaplastic large-cell lymphoma (ALCL) is an extremely rare type of PBL, and it remains unclear whether ALCLs that primarily involve the bone exhibit favourable or unfavourable biological behaviour, and whether they are similar to ALCLs in general, or not. We reported a case of ALK-positive ALCL with primary bone involvement, and reviewed the clinicopathological features of 22 previously reported cases. An ALCL with primary bone involvement mostly affects younger patients with a preponderant towards the involvement of axial-bone. The prognosis of an ALCL that primarily involves bone is unfavourable, compared with PBL generally. The ALK-positive ALCLs in PBLs had less decedents than the ALK-negative ALCLs with a statistical non-significance (p=0.198).

Measurement of levels of fractional exhaled nitric oxide in patients with pulmonary tuberculosis

SETTING

The role of fractional exhaled nitric oxide (FeNO) in the diagnosis and treatment of pulmonary tuberculosis (PTB) is uncertain.

OBJECTIVE

To examine the value of FeNO as a biomarker for PTB.

DESIGN

Baseline FeNO levels were compared in 69 PTB patients and 118 healthy controls. The correlation between baseline FeNO levels and clinical variables of tuberculosis were studied. FeNO levels were checked twice in the PTB group, at diagnosis and after 2 months of anti-tuberculosis medication, and factors affecting changes in FeNO levels after treatment were analysed.

RESULTS

FeNO levels were not significantly different in the PTB group and controls (mean ± standard deviation 27.7 ± 17.6 parts per billion [ppb] vs. 27.0 ± 10.8 ppb, P = 0.531). In a multivariate regression analysis, no variable was shown to affect FeNO levels at diagnosis. FeNO levels did not significantly change after 2 months of treatment (26.8 ± 18.3 ppb vs. 24.0 ± 10.7 ppb, P = 0.257). Only PTB with a high FeNO level (>25 ppb) was related to a decline in FeNO levels after 2 months of treatment.

CONCLUSION

FeNO levels do not appear to be affected in PTB patients.

Prognostic significance of microvascular invasion in tumor stage for hepatocellular carcinoma

BACKGROUND

The presence of microvascular invasion (McVI) in hepatocellular carcinoma (HCC) has been proposed as a cause of recurrence and poor survival, although this has not been officially emphasized in staging systems. Thus, we conducted a retrospective study to investigate the prognostic importance of McVI in tumor staging in patients with HCC who underwent hepatic resection.

METHODS

A retrospective analysis was performed of patients who underwent hepatic resection for HCC at our center from 1994 to 2012. Patients with HCC were classified into four groups based on the presence of McVI and extent of gross vascular invasion (VI).

RESULTS

The 5-year overall and recurrence-free survival rates of 676 patients were 63.3 and 42.6%, respectively. There was no difference in tumor recurrence or survival rate between patients with HCC and McVI without gross VI and those with gross VI confined to segmental/sectional branches. Multivariate analysis revealed that the extent of VI based on the presence of McVI and gross VI was independently associated with tumor recurrence and overall survival.

CONCLUSIONS

McVI was revealed to be an important risk factor similar to gross VI confined to a segmental/sectional branch in patients with HCC who underwent hepatic resection. This finding should be considered when estimating the stage for prognosis.

Bioimaging of multiple piRNAs in a single breast cancer cell using molecular beacons

Simultaneous bioimaging of piR-36026 and piR-36743 using molecular beacons successfully visualized 4 different subtypes of breast cancer.

Analysis of the proficiency of single radial immunodiffusion assays for quality control of influenza vaccines in Korea

Influenza vaccine potency, which is determined by quantitatively measuring the content of Hemagglutinin (HA), is an essential index representing the efficacy of the vaccine. Standardization of the single radial immunodiffusion (SRID) assay, a method for measuring HA content, and proficiency of the testing institutions are crucial for influenza vaccine quality control. Herein, we assessed the proficiency of SRID assays at the National Control Laboratory (NCL) of Korea and several vaccine manufacturers. Eight laboratories participated in this study, and the proficiencies of all laboratories yielded satisfactory results in overall SRID assays. In contrast, there were some unsatisfactory results in measuring with different types of agarose gel plates produced by other laboratories. Overall, our findings demonstrated that the proficiency of SRID assay in the tested laboratories is acceptable for quality control of influenza vaccines and that detailed review on the validation reports regarding the test methods will be helpful for better control.

Mutations acquired by hepatocellular carcinoma recurrence give rise to an aggressive phenotype

Recurrence of hepatocellular carcinoma (HCC) even after curative resection causes dismal outcomes of patients. Here, to delineate the driver events of genomic and transcription alteration during HCC recurrence, we performed RNA-Seq profiling of the paired primary and recurrent tumors from two patients with intrahepatic HCC. By comparing the mutational and transcriptomic profiles, we identified somatic mutations acquired by HCC recurrence including novel mutants of GOLGB1 (E2721V) and SF3B3 (H804Y). By performing experimental evaluation using siRNA-mediated knockdown and overexpression constructs, we demonstrated that the mutants of GOLGB1 and SF3B3 can promote cell proliferation, colony formation, migration, and invasion of liver cancer cells. Transcriptome analysis also revealed that the recurrent HCCs reprogram their transcriptomes to acquire aggressive phenotypes. Network analysis revealed CXCL8 (IL-8) and SOX4 as common downstream targets of the mutants. In conclusion, we suggest that the mutations of GOLGB1 and SF3B3 are potential key drivers for the acquisition of an aggressive phenotype in recurrent HCC.

Effects of kinetic chain exercise using EMG-biofeedback on balance and lower extremity muscle activation in stroke patients

[Purpose] The purpose of this study was to examine the effect of kinetic chain exercise using EMG-biofeedback on balance and lower extremity muscle activation. [Subjects and Methods] For this study, 30 stroke patients participated in this study and they were divided into closed kinetic chain exercise using EMG-biofeedback group (CKCE+EB) and open kinetic chain exercise using EMG-biofeedback group (OKCE+EB), each group consisting of 15 patients. The kinetic chain exercise using EMG-biofeedback was performed by the patients for 20 minutes once a day, 5 days a week, for 6 weeks using an Myo-Ex. BioRescue was used to measure balance ability, while surface EMG was used to measure the lower extremity muscle activation. [Results] According to the results of the comparison within the groups, after the intervention, both groups showed significant increases in the balance ability and lower extremity muscle activation. In the comparisons between the groups, after the intervention, balance ability and lower extremity muscle activation were significantly higher in the CKCE+BE than in the OKCE+EB. [Conclusion] This study showed that closed kinetic chain exercise using EMG-biofeedback is effective for improving balance ability and lower extremity muscle activation in stroke patients.

Augmented reality in bone tumour resection: An experimental study

OBJECTIVES

We evaluated the accuracy of augmented reality (AR)-based navigation assistance through simulation of bone tumours in a pig femur model.

METHODS

We developed an AR-based navigation system for bone tumour resection, which could be used on a tablet PC. To simulate a bone tumour in the pig femur, a cortical window was made in the diaphysis and bone cement was inserted. A total of 133 pig femurs were used and tumour resection was simulated with AR-assisted resection (164 resection in 82 femurs, half by an orthropaedic oncology expert and half by an orthopaedic resident) and resection with the conventional method (82 resection in 41 femurs). In the conventional group, resection was performed after measuring the distance from the edge of the condyle to the expected resection margin with a ruler as per routine clinical practice.

RESULTS

The mean error of 164 resections in 82 femurs in the AR group was 1.71 mm (0 to 6). The mean error of 82 resections in 41 femurs in the conventional resection group was 2.64 mm (0 to 11) (p < 0.05, one-way analysis of variance). The probabilities of a surgeon obtaining a 10 mm surgical margin with a 3 mm tolerance were 90.2% in AR-assisted resections, and 70.7% in conventional resections.

CONCLUSION

We demonstrated that the accuracy of tumour resection was satisfactory with the help of the AR navigation system, with the tumour shown as a virtual template. In addition, this concept made the navigation system simple and available without additional cost or time.Cite this article: H. S. Cho, Y. K. Park, S. Gupta, C. Yoon, I. Han, H-S. Kim, H. Choi, J. Hong. Augmented reality in bone tumour resection: An experimental study. Bone Joint Res 2017;6:137-143.

Blood Neutrophil-to-Lymphocyte Ratio Predicts Tumor Recurrence in Patients with Hepatocellular Carcinoma within Milan Criteria after Hepatectomy

PURPOSE

The systemic inflammation biomarker, Neutrophil-to-Lymphocyte Ratio (NLR), has been reported as one of the adverse prognostic factors for hepatocellular carcinoma (HCC) patient. The purpose of this study was to evaluate whether NLR could predict the risk of recurrence and death for the HCC patient, according to Milan criteria after hepatectomy.

MATERIALS AND METHODS

Retrospective analysis was performed on a database of HCC patients who underwent hepatectomy between March 2001 and December 2011. The cutoff value of NLR was decided by receiver operating characteristic (ROC) curve analysis. Univariate and multivariate regression analyses were performed to identify predictive factors of recurrence and death.

RESULTS

A total of 213 patients were included in the present study. The median follow-up period was 48 months. One hundred and seven patients were experienced tumor recurrence; forty of them recurred within 12 months (early recurrence). NLR ≥1.505, albumin ≤3.75 g/dL, microvascular invasion and high grade of cirrhosis were found to be independent factors for adverse recurrence-free survival in multivariate regression analysis. And NLR ≥1.945 was also found as a prognosis factor for early recurrence by univariate regression analysis.

CONCLUSION

Elevated preoperative NLR can be easily obtained and reliable biomarker for assessing the tumor recurrence and early recurrence of Milan criteria HCC after the initial hepatectomy.

Mucosa-associated lymphoid tissue (MALT) lymphoma as an unusual cause of malignant hilar biliary stricture: a case report with literature review

Background

Biliary strictures at the hilum of the liver arise from heterogeneous etiologies. The majority is malignant entities, but some may have benign etiologies. It is difficult to distinguish between malignant and benign biliary strictures preoperatively. It has been reported that 5~15 % of preoperative diagnoses of hilar cholangiocarcinoma turn out to be benign lesions or even other types of malignancies. Primary non-Hodgkin’s lymphoma of the extrahepatic bile duct is very rare, with only a few cases reported as mucosa-associated lymphoid tissue (MALT) lymphoma arising from the hepatic duct bifurcation. We herein report a case of a female patient presenting with perihilar bile ducts obstructed by primary MALT lymphoma resembling hilar cholangiocarcinoma, along with a review of the literature.

Case presentation

An 86-year-old female was referred to our hospital manifesting obstructive jaundice and abdominal pain. The reported imaging studies revealed distended intrahepatic bile duct with the stricture of common hepatic duct including bifurcation, which was suspicious of cholangiocarcinoma of the bile duct. The initial laboratory-confirmed cholestasis with a total bilirubin of 8.6 mg/dL, aspartate amino transferase (AST) 178 U/L, alanine transferase (ALT) 105 U/L, and the tumor marker CA 19-9 was elevated with a value of 167 U/mL. Viral markers for hepatitis B and C viruses were negative. She underwent extrahepatic bile duct resection and hepaticojejunostomy. Histological examination of the resected specimen revealed MALT lymphoma. Postoperative follow-up of 1 year has been completely uneventful, without any symptoms or disease recurrence.

Conclusions

In exceptional cases, in which radiologic and clinical features point to cholangiocarcinoma, the actual reason for obstructive jaundice and abdominal pain can be a non-Hodgkin’s lymphoma. In the case of a MALT lymphoma, it can be cured with complete resection.

Multiplex bioimaging of piRNA molecular pathway-regulated theragnostic effects in a single breast cancer cell using a piRNA molecular beacon

Recently, PIWI-interacting small non-coding RNAs (piRNAs) have emerged as novel cancer biomarkers candidate because of their high expression level in various cancer types and role in the control of tumor suppressor genes. In this study, a novel breast cancer theragnostics probe based on a single system targeting the piRNA-36026 (piR-36026) molecular pathway was developed using a piR-36026 molecular beacon (MB). The piR-36026 MB successfully visualized endogenous piR-36026 biogenesis, which is highly expressed in MCF7 cells (a human breast cancer cell line), and simultaneously inhibited piR-36026-mediated cancer progression in vitro and in vivo. We discovered two tumor suppressor proteins, SERPINA1 and LRAT, that were directly regulated as endogenous piR-36026 target genes in MCF7 cells. Furthermore, multiplex bioimaging of a single MCF7 cell following treatment with piR-36026 MB clearly visualized the direct molecular interaction of piRNA-36026 with SERPINA1 or LRAT and subsequent molecular therapeutic responses including caspase-3 and PI in the nucleus.

Complete Oxidation of Toluene Over Supported Palladium Catalysts: Effect of Support

The catalytic oxidation of toluene was carried out to investigate the effect of the support on the properties and performance of a supported palladium catalyst (1 wt% loading). γ-Al2O3), SiO2 and TiO2 were used as supports. The properties of the prepared catalysts were characterized by XRD, BET, PT, TPD, TPR, XPS and FE-TEM analyses. The experimental results showed that the order of catalytic performance was 1 wt% Pd/TiO2 > 1 wt% Pd/SiO2 > 1 wt% Pd/γ-Al2O3. A strong interaction between the palladium and support was found, which affected the palladium surface concentration and particle size. The higher catalytic activity of the Pd/TiO2 catalyst was attributed to the higher palladium surface concentration and larger particle size.

Synthesis of Dicyclopentadiene Oligomer Over Nanoporous Al-MCM-41 Catalysts

One step reaction composed of DCPD oligomerization and DCPD oligomer isomerization was investigated over nanoporous Al-MCM-41 catalysts. The effects of aluminum grafting over MCM-41 on the catalyst characteristics were studied with respect to the synthesis of TCPD isomer. Physical and chemical properties of the catalysts were analyzed by N2 adsorption, temperature-programmed desorption of ammonia, and infrared spectroscopy of adsorbed pyridine. The overall number of acid sites as well as the number of Lewis acid sites increased with increasing of aluminum content over MCM-41. When utilizing MCM-41 and Al-MCM-41 as the catalyst, DCPD oligomerization reaction activity greatly increased compared to the thermal reaction. The highest TCPD isomer selectivity over the Al-MCM-41 catalyst with the highest aluminum content could be ascribed to the largest amount of acid sites. This study showed an increased level of TCPD isomer selectivity by an increasing level of Lewis acid sites through aluminum addition over MCM-41.

Catalytic Fast Pyrolysis of Wild Reed Over Nanoporous SBA-15 Catalysts

Wild reed was pyrolyzed over two nanoporous SBA-15 catalysts with different acid characteristics: Si-SBA-15 and Al-SBA-15. Al was grafted on Si-SBA-15 to increase the acidity and enhance the catalytic activity. Fast pyrolysis was carried out using a pyrolysis-gas chromatography/mass spectrometry system at 550 degrees C for real-time analysis of the products. Significant improvement of the product bio-oil quality was attained by catalytic reforming over nanoporous Al-SBA-15. The fraction of total oxygenates was reduced because of the decrease in. the fraction of ketones, aldehydes, and carboxylates, which deteriorate the fuel quality of bio-oil. On the other hand, the fractions of furans and aromatics, which are the chemicals with high value-added, were increased by the catalytic reforming. The catalytic activity of Al-SBA-15 was considerably higher than that of Si-SBA-15 because the incorporation of Al increased the catalyst acidity.

Facile Synthesis of Iron Oxide/Graphene Nanocomposites Using Liquid Phase Plasma Method

Liquid phase plasma (LPP) method was applied, for the first time, to the impregnation of iron oxide nanoparticles onto graphene sheet. Iron oxide nanoparticles with the size of 50 nm were precipitated with uniform dispersion on the surface of graphene sheet. The amount of iron oxide nanoparticles precipitated on graphene sheets increased with increasing LPP process times. The XPS, Raman and EDX analyses showed that the iron oxide/graphene composites synthesized by the LPP process.

Application of Silver and Silver Oxide Nanoparticles Impregnated on Activated Carbon to the Degradation of Bromate

Silver and silver oxide nanoparticles were impregnated on the surface of powdered activated carbon (PAC) using a single-step liquid phase plasma (LPP) method. Spherical silver and silver oxide nanoparticles of 20 to 100 nm size were dipersed evenly on the surface of PAC. The impregnated PAC exhibited a higher activity for the decomposition of bromate than bare PAC. The XPS, Raman and EDX analyses showed that the Ag/PAC composites synthesized by the LPP process.

Catalytic Reforming of Lignin-Derived Bio-Oil Over a Nanoporous Molecular Sieve Silicoaluminophosphate-11

Catalytic pyrolysis of lignin, a major constituent of biomass, was performed. A nanoporous molecular sieve silicoaluminophosphate-11 (SAPO-11) was selected as catalyst. Thermogravimetric analysis showed that 500 degrees C was the optimal pyrolysis temperature. Pyrolyzer-gas chromatography/mass spectroscopy was used to investigate the pyrolysis product distribution. Production of phenolics, the dominant product from the pyrolysis of lignin, was promoted by the increase in the catalyst dose. In particular, low-molecular-mass phenolics were produced more over SAPO-11, while high-molecular-mass phenolics and double-bond-containing phenolics were produced less. The fraction of aromatic compounds, including benzene, toluene, xylene, and ethylbenzene, was also increased by catalytic reforming. The catalytic effects were more pronounced when the catalyst/biomass ratio was increased. The enhanced production of aromatic compounds by an acidic catalyst obtained in this study is in good agreement with the results of previous studies.

Clinical commissioning of an in vivo range verification system for prostate cancer treatment with anterior and anterior oblique proton beams

The purpose of this work is the clinical commissioning of a recently developed in vivo range verification system (IRVS) for treatment of prostate cancer by anterior and anterior oblique proton beams. The IRVS is designed to perform a complete workflow for pre-treatment range verification and adjustment. It contains specifically designed dosimetry and electronic hardware and a specific software for workflow control with database connection to the treatment and imaging systems. An essential part of the IRVS system is an array of Si-diode detectors, designed to be mounted to the endorectal water balloon routinely used for prostate immobilization. The diodes can measure dose rate as function of time from which the water equivalent path length (WEPL) and the dose received are extracted. The former is used for pre-treatment beam range verification and correction, if necessary, while the latter is to monitor the dose delivered to patient rectum during the treatment and serves as an additional verification. The entire IRVS workflow was tested for anterior and 30 degree inclined proton beam in both solid water and anthropomorphic pelvic phantoms, with the measured WEPL and rectal doses compared to the treatment plan. Gafchromic films were also used for measurement of the rectal dose and compared to IRVS results. The WEPL measurement accuracy was in the order of 1 mm and after beam range correction, the dose received by the rectal wall were 1.6% and 0.4% from treatment planning, respectively, for the anterior and anterior oblique field. We believe the implementation of IRVS would make the treatment of prostate with anterior proton beams more accurate and reliable.

Establishment of the 3rd national standard for lot release testing of the Japanese encephalitis vaccine (Nakayama-NIH strain) in Korea

In Korea, 2 inactivated Japanese encephalitis vaccines from Nakayama-NIH and Beijing-1 strain have been utilized to date. The 1^st national standard for lot release testing of the JE vaccine was established in 2002. The 2^nd national standard, established in 2007, is currently in use for JE vaccine (Nakayama-NIH strain) potency testing. However, the supply of this standard is expected to be exhausted by 2015, necessitating the establishment of a new national standard with quality equivalent to that of the existing standard. Quality control tests were performed to verify that the new standard candidate material was equivalent to that of the 2^nd national standard, proving its appropriateness for potency testing of JE vaccine. In addition, based on the results of a collaborative study conducted among 4 institutions including Ministry of Food and Drug Safety, the potency of the new national standard material was determined to be 2.69 neutralizing-antibody titer (log₁₀) per vial. Therefore, the newly established national standard material is expected to be used for the Japanese encephalitis vaccine lot release in Korea.

The Effects of Ethanol on the Morphological and Biochemical Properties of Individual Human Red Blood Cells

Here, we report the results of a study on the effects of ethanol exposure on human red blood cells (RBCs) using quantitative phase imaging techniques at the level of individual cells. Three-dimensional refractive index tomograms and dynamic membrane fluctuations of RBCs were measured using common-path diffraction optical tomography, from which morphological (volume, surface area, and sphericity); biochemical (hemoglobin (Hb) concentration and Hb content); and biomechanical (membrane fluctuation) parameters were retrieved at various concentrations of ethanol. RBCs exposed to the ethanol concentration of 0.1 and 0.3% v/v exhibited cell sphericities higher than those of normal cells. However, mean surface area and sphericity of RBCs in a lethal alcoholic condition (0.5% v/v) are not statistically different with those of healthy RBCs. Meanwhile, significant decreases of Hb content and concentration in RBC cytoplasm at the lethal condition were observed. Furthermore, dynamic fluctuation of RBC membranes increased significantly upon ethanol treatments, indicating ethanol-induced membrane fluidization.

Comparison of outcomes after laparoscopy-assisted and open total gastrectomy for early gastric cancer

BACKGROUND

The aim of this study was to compare the results of laparoscopy-assisted total gastrectomy with those of open total gastrectomy for early gastric cancer.

METHODS

Patients with gastric cancer who underwent total gastrectomy with curative intent in three Korean tertiary hospitals between January 2003 and December 2010 were included in this multicentre, retrospective, propensity score-matched cohort study. Cox proportional hazards regression models were used to evaluate the association between operation method and survival.

RESULTS

A total of 753 patients with early gastric cancer were included in the study. There were no significant differences in the matched cohort for overall survival (hazard ratio (HR) for laparoscopy-assisted versus open total gastrectomy 0.96, 95 per cent c.i. 0.57 to 1.65) or recurrence-free survival (HR 2.20, 0.51 to 9.52). The patterns of recurrence were no different between the two groups. The severity of complications, according to the Clavien-Dindo classification, was similar in both groups. The most common complications were anastomosis-related in the laparoscopy-assisted group (8.0 per cent versus 4.2 per cent in the open group; P = 0.015) and wound-related in the open group (1.6 versus 5.6 per cent respectively; P = 0.003). Postoperative death was more common in the laparoscopy-assisted group (1.6 versus 0.2 per cent; P = 0.045).

CONCLUSION

Laparoscopy-assisted total gastrectomy for early gastric cancer is feasible in terms of long-term results, including survival and recurrence. However, a higher postoperative mortality rate and an increased risk of anastomotic leakage after laparoscopic-assisted total gastrectomy are of concern.

Transcriptomic analysis of colistin-susceptible and colistin-resistant isolates identifies genes associated with colistin resistance in Acinetobacter baumannii

The emergence of colistin-resistant Acinetobacter baumannii is concerning, as colistin is often regarded as the last option for treating multidrug-resistant (MDR) A. baumannii infections. Using mRNA sequencing, we compared whole transcriptomes of colistin-susceptible and colistin-resistant A. baumannii strains, with the aim of identifying genes involved in colistin resistance. A clinical colistin-susceptible strain (06AC-179) and a colistin-resistant strain (07AC-052) were analysed in this study. In addition, a colistin-resistant mutant (06AC-179-R1) derived from 06AC-179 was also included in this study. High throughput mRNA sequencing was performed with an Illumina HiSeq TM 2000. In total, six genes were identified as associated with colistin resistance in A. baumannii. These six genes encode PmrAB two-component regulatory enzymes, PmrC (a lipid A phosphoethanolamine transferase), a glycosyltransferase, a poly-β-1,6-N-acetylglucosamine deacetylase, and a putative membrane protein. Matrix-assisted laser desorption/ionization time of flight mass spectrometry revealed that all three colistin-resistant strains used in this study had modified lipid A structure by addition of phosphoethanolamine. As genes found in our results are all associated with either lipopolysaccharide biosynthesis or electrostatic changes in the bacterial cell membrane, lipopolysaccharide modification might be one of the principal modes of acquisition of colistin resistance in some A. baumannii strains.

Isolated fallopian tube torsion during pregnancy: a case report

Isolated fallopian tube torsion is a rare pregnancy-related complication. It is frequently misdiagnosed as acute appendicitis or ovarian torsion owing to the lack of specific symptoms or signs. Here, the authors report a case of a 35-year-old primigravida at 30 weeks and six days of gestation who had presented with right isolated fallopian tube torsion and a history of right oophorectomy. The authors propose that isolated fallopian tube torsion should be included in the list of differential diagnosis when encountered with patients complaining of lower abdominal pain.

Bone regeneration at dental implant sites with suspended stem cells

During the maintenance of bone marrow-derived mesenchymal stem cells (BMMSCs), suspended cells are discarded normally. We noted the osteogenic potential of these cells to be like that of anchorage-dependent BMMSCs. Therefore, we characterized suspended BMMSCs from rabbit bone marrow by bioengineering and applied the suspended BMMSCs to double-canaled dental implants inserted into rabbits. After primary isolation of BMMSCs, we collected the suspended cells during primary culture on the third day. The cells were transferred and maintained on an extracellular-matrix-coated culture plate. The cells were characterized and compared with BMMSCs by colony-forming-unit fibroblast (CFU-f) and cell proliferation assay, fluorescence-activated cell sorter (FACS), in vitro multipotency, and reverse transcription polymerase chain reaction (RT-PCR). We also analyzed the osteogenic potential of cells mixed with hydroxyapatite/tricalcium phosphate (HA/TCP) and transplanted into immunocompromised mice. We compared the viability and proliferation of the suspended BMMSCs and BMMSCs on the titanium implant surface and observed cell morphology. Then, the cells mixed with HA/TCP were applied to the double-canaled implants during installation into rabbit tibia. Four weeks later, we analyzed bone formation inside the canal by histomorphometry. The suspended cells showed higher CFU-f on the extracellular matrix (ECM)-coated culture plate and similar results of proliferation capacity compared with BMMSCs. The cells also showed osteogenic, adipogenic, and chondrogenic ability. The suspended cells showed levels of attachment survival and proliferation on the surfaces of titanium implant discs to be higher than or similar to those of BMMSCs. The suspended cells as well as BMMSCs showed stronger bone formation ability in both upper and lower canals of the implants compared with controls on double-canaled implants inserted into rabbit tibia. In this study, we showed that suspended cells after primary BMMSC isolation have bone regeneration capacity like that of BMMSCs, not only in vitro but also in vivo. ECM was valuable for propagation of MSCs for cell-based bone regeneration. Therefore, the suspended cells could also be useful tools for bone regeneration after implant surgery.

Tumor differentiation is not a risk factor for lymph node metastasis in elderly patients with early gastric cancer

BACKGROUND

The aim of this study was to identify risk factors for lymph node metastasis in elderly patients (70 years or more) with early gastric cancer.

METHODS

We reviewed the prospectively collected database of 6893 patients with early gastric cancer who had undergone curative gastrectomy in 3 tertiary cancer centers between January 2003 and December 2009 in Korea. Patients were sorted into 4 groups according to age: less than 50, fifties, sixties, and 70 years or more. Risk factors for lymph node metastasis in early gastric cancer were analyzed.

RESULTS

One thousand and thirty five patients (15.0%) were 70 years or more. As age increased, the frequency of large differentiated tumor, lymphatic and submucosa invasion increased. Old age was associated with a lower risk for lymph node metastasis in patients with early gastric cancer (Odds ratio [OR], OR, 0.622; 95% CI, 0.5466-0.830, P = 0.010). Ulceration or differentiation of tumor was not associated with lymph node metastasis in elderly patients with early gastric cancer.

CONCLUSIONS

Elderly patients with undifferentiated type histology early gastric cancer without other risk factors for lymph node metastasis may be candidates for endoscopic resection.

Influence of preoperative transcatheter arterial chemoembolization on gene expression in the HIF-1α pathway in patients with hepatocellular carcinoma

PURPOSE

Although transcatheter arterial chemoembolization (TACE) is the most common treatment option in patients with hepatocellular carcinoma (HCC), its clinical benefits remain still controversial. Since TACE induces hypoxic necrosis in tumors, hypoxia-inducible factor 1α (HIF-1α) could critically affect biology in residual tumors after TACE treatment and subsequent prognosis. However, HIF-1α and its prognostic relevance in TACE have rarely been examined in human specimens. In the current study, we investigated the prognosis and expression of genes regulated by HIF-1α in HCC patients receiving preoperative TACE for the first time.

METHODS

In total, 35 patients with HCC (10 patients undergoing preoperative TACE) were retrospectively studied. The prognostic significance of TACE was analyzed using Kaplan-Meier and Cox regression models. Protein levels of HIF-1α and mRNA levels of HIF-1α-associated genes were examined using immunohistochemistry (IHC) and real-time RT-PCR, respectively.

RESULTS

Preoperative TACE was significantly associated with increased 2-year recurrence rate (80 vs. 36 %, P = 0.00402) and shorter disease-free survival (DFS) time (11.9 vs. 35.7 months, P = 0.0182). TACE was an independent prognostic factor for recurrence (P = 0.007) and poor DFS (P = 0.010) in a multivariate analysis. Immunohistochemical staining revealed in vivo activation of HIF-1α in human specimens treated with TACE. Notably, protein levels of HIF-1α were significantly increased in TACE tissues demonstrated by IHC. Transcriptional targets of HIF-1α showed mRNA expression patterns consistent with activation of HIF-1α in TACE tissues.

CONCLUSIONS

Our findings collectively demonstrate that preoperative TACE confers poor prognosis in HCC patients through activation of HIF-1α.

Lead-free LiNbO3 nanowire-based nanocomposite for piezoelectric power generation

In a flexible nanocomposite-based nanogenerator, in which piezoelectric nanostructures are mixed with polymers, important parameters to increase the output power include using long nanowires with high piezoelectricity and decreasing the dielectric constant of the nanocomposite. Here, we report on piezoelectric power generation from a lead-free LiNbO3 nanowire-based nanocomposite. Through ion exchange of ultra-long Na2Nb2O6-H2O nanowires, we synthesized long (approximately 50 μm in length) single-crystalline LiNbO3 nanowires having a high piezoelectric coefficient (d33 approximately 25 pmV-1). By blending LiNbO3 nanowires with poly(dimethylsiloxane) (PDMS) polymer (volume ratio 1:100), we fabricated a flexible nanocomposite nanogenerator having a low dielectric constant (approximately 2.7). The nanogenerator generated stable electric power, even under excessive strain conditions (approximately 105 cycles). The different piezoelectric coefficients of d33 and d31 for LiNbO3 may have resulted in generated voltage and current for the e33 geometry that were 20 and 100 times larger than those for the e31 geometry, respectively. This study suggests the importance of the blending ratio and strain geometry for higher output-power generation in a piezoelectric nanocomposite-based nanogenerator. PACS: 77.65.-j; 77.84.-s; 73.21.Hb.

Mutations in thegyrAandparCGenes in Ciprofloxacin-Resistant Clinical Isolates ofAcinetobacter baumanniiin Korea

Mutation with Ser-83-->Leu in gyrA gene was associated with the principal mutation for ciprofloxacin resistance in clinical isolates of Acinetobacter baumannii. Double mutation, Ser-83-->Leu in gyrA gene and Ser-80-->Leu in parC gene, was the most frequently detected among ciprofloxacin-resistant isolates. A novel mutation with Ser-80-->Trp in parC gene, in addition to mutation in gyrA gene, was associated with a high-level ciprofloxacin resistance. These results suggested that the presence of an additional mutation in the parC gene contributed to a higher-level of ciprofloxacin resistance than a single mutation in the gyrA gene (geometric mean MICs of ciprofloxacin, 44.1 versus 16 microg/ml, P < 0.05).

Functional insight from the tetratricopeptide repeat-like motifs of the type III secretion chaperone SicA in Salmonella enterica serovar Typhimurium

SicA functions both as a class II chaperone for SipB and SipC of the type III secretion system (T3SS)-1 and as a transcriptional cofactor for the AraC-type transcription factor InvF in Salmonella enterica subsp. enterica serovar Typhimurium. Bioinformatic analysis has predicted that SicA possesses three tetratricopeptide repeat (TPR)-like motifs, which are important for protein-protein interactions and serve as multiprotein complex mediators. To investigate whether the TPR-like motifs in SicA are critical for its transcriptional cofactor function, the canonical residues in these motifs were mutated to glutamate (SicAA44E , SicAA78E , and SicAG112E ). None of these mutants except SicAA44E were able to activate the expression of the sipB and sigD genes. SicAA44E still has a capacity to interact with InvF in vitro, and despite its instability in cell, it could activate the sigDE operon. This suggests that TPR motifs are important for the transcriptional cofactor function of the SicA chaperone.

Epidemiology and clinical features of post-transplant bloodstream infection: an analysis of 222 consecutive liver transplant recipients

BACKGROUND

Bloodstream infection (BSI) is a significant cause of morbidity and mortality in liver transplant (LT) recipients. This study aimed to investigate the epidemiology and clinical features of post-transplant BSI in LT recipients.

MATERIALS AND METHODS

The microbiology, frequency, and outcome of post-transplant BSI in the first year after LT were retrospectively analyzed in 222 consecutive patients who had received liver transplants at a single center between 2005 and 2011. The risk factors for post-transplant BSI and death were evaluated.

RESULTS

During a 1-year period after LT, 112 episodes of BSI occurred in 64 of the 222 patients (28.8%). A total of 135 microorganisms were isolated from 112 BSI episodes including 18 polymicrobial episodes. The median time to BSI onset ranged from 8 days for Klebsiella pneumoniae to 101 days for enterococci, and the overall median for all microorganisms was 28 days. The most frequent pathogens were Enterobacteriaceae members (32.5%), enterococci (17.8%), yeasts (14.0%), Staphylococcus aureus (10.3%), and Acinetobacter baumannii (10.3%); most of them showed resistance to major antibiotics. The major sources of BSI were biliary tract (36.2%), abdominal and/or wound (28.1%), and intravascular catheter (18.5%) infections. The independent risk factors for post-transplant BSI were biliary complications (odds ratio [OR]: 2.91, 95% confidence interval [CI]: 1.29 to 6.59, P = 0.010) and longer hospitalization in the intensive care unit (OR: 1.04, 95% CI: 1.00 to 1.08, P < 0.001) after LT. BSI was an independent risk factor for death (hazard ratio [HR]: 3.92, 95% CI: 2.22 to 6.91, P < 0.001), with a poorer survival rate observed in patients with BSI than in those without BSI (1-year survival rate: 60.0% versus 89.5%, respectively, P < 0.001) after LT. The strongest predictors for death in patients with BSI were hepatocellular carcinoma (HR: 3.82, 95% CI: 1.57 to 9.32, P = 0.003), candidemia (HR: 3.71, 95% CI: 1.58 to 8.71, P = 0.003), polymicrobial bacteremia (HR: 3.18, 95% CI: 1.39 to 7.28, P = 0.006), and post-transplant hemodialysis (HR: 2.44, 95% CI: 1.02 to 5.84, P = 0.044).

CONCLUSIONS

BSI was a frequent post-transplant complication, and most of the causative pathogens were multi-drug resistant. Biliary complications and BSIs resulting from biliary infection are major problems for LT recipients. The prevention of BSI and biliary complications is critical in improving prognosis in liver transplant recipients.

Simple, direct drug susceptibility testing technique for diagnosis of drug-resistant tuberculosis in resource-poor settings

SETTING

The Korean Institute of Tuberculosis, Seoul, Republic of Korea.

OBJECTIVE

To develop a simple, direct drug susceptibility testing (DST) technique using Kudoh-modified Ogawa (KMO) medium.

DESIGN

The critical concentrations of isoniazid (INH), rifampicin (RMP), kanamycin (KM) and ofloxacin (OFX) for KMO medium were calibrated by comparing the minimal inhibitory concentrations (MICs) against clinical isolates of Mycobacterium tuberculosis on KMO with those on Löwenstein-Jensen (LJ). The performance of the direct KMO DST technique was evaluated on 186 smear-positive sputum specimens and compared with indirect LJ DST.

RESULTS

Agreement of MICs on direct vs. indirect DST was high for INH, RMP and OFX. KM MICs on KMO were ∼10 g/ml higher than those on LJ. The critical concentrations of INH, RMP, OFX and KM for KMO were therefore set at 0.2, 40.0, 2.0, and 40.0 g/ml. The evaluation of direct DST of smear-positive sputum specimens showed 100% agreement with indirect LJ DST for INH and RMP. However, the respective susceptible and resistant predictive values were 98.8% and 100% for OFX, and 100% and 80% for KM.

CONCLUSION

Direct DST using KMO is useful, with clear advantages of a shorter turnaround time, procedural simplicity and low cost compared to indirect DST. It may be most indicated in resource-poor settings for programmatic management of drug-resistant tuberculosis.

RaoN, a small RNA encoded within Salmonella pathogenicity island-11, confers resistance to macrophage-induced stress

Bacterial small non-coding RNAs act as important regulators that control numerous cellular processes. Here we identified RaoN, a novel small RNA encoded in the cspH-envE intergenic region on Salmonella pathogenicity island-11 (SPI-11). RaoN contributes to survival under conditions of acid and oxidative stress combined with nutrient limitation, which partially mimic the intramacrophage environment. Indeed, inactivation of raoN reduces the intramacrophage replication of Salmonella enterica serovar Typhimurium. Genome-wide transcriptome analysis revealed that the lactate dehydrogenase gene ldhA is upregulated in the raoN knockout mutant. Notably, both inactivation and overexpression of ldhA in the WT strain render Salmonella more sensitive to oxidative stress, particularly when combined with nutrient limitation. However, ldhA is not the sole determinant of RaoN function in facilitating intramacrophage survival of Salmonella. Together, our data suggest that balanced regulation of ldhA expression by RaoN is necessary for survival under in vitro stress conditions and contributes to the intramacrophage growth of Salmonella.

A multivalent peptide as an activator of hypoxia inducible factor-1α

Hypoxia inducible factor-1α (HIF-1α) is a transcription factor found in mammalian cells under hypoxia. While HIF-1α in hypoxia translocates to the nucleus where it transcribes the target genes including vascular endothelial growth factor (VEGF) mRNA, HIF-1α is degraded under normoxia, which involves its proline hydroxylation and subsequent binding to the von Hippel-Lindau protein-Elongin B-Elogin C (VBC) complex. Previously, peptide inhibitors against this interaction between hydroxylated HIF-1α and VBC have been developed to stabilize the transcriptional activity of HIF-1α by preventing the degradation of the protein even under normoxia. Despite the specific inhibition by these peptides, their poor inhibition potency needs to be improved for further clinical application. In this work, we have designed and prepared a streptavidin-based multivalent peptide inhibitor against the HIF-1α-VBC complexation. We have evaluated the potency of the multivalent peptide in terms of stabilization of HIF-1α and the downstream effect. As the result, we have found that the inhibitor showed about 13-fold lowered IC50 value compared with that of the corresponding monovalent peptide, thereby activating HIF-1α and leading to up-regulation of VEGF protein at the cellular level.

Expression and delivery of tetanus toxin fragment C fused to the N-terminal domain of SipB enhances specific immune responses in mice

Live attenuated bacteria can be used as a carrier for the delivery of foreign antigens to a host's immune system. The N-terminal domain of SipB, a translocon protein of the type III secretion system of Salmonella enterica serovar Typhimurium, is required for secretion and outer membrane localization. In the present study, vaccine plasmids for antigen delivery in which the non-toxic tetanus toxin fragment C (TTFC), which contains a T cell epitope, is fused to the N-terminal 160 amino acids of SipB were developed. It was found that the recombinant proteins are secreted into the culture media and localized to the bacterial surface. TTFC-specific antibody responses are significantly increased in mice orally immunized with attenuated S. Typhimurium BRD509 strains carrying TTFC delivery plasmids. When the TTFC delivery cassettes were introduced into a low copy vector, the plasmid was stably maintained in the BRD509 strain and induced an immune response to the TTFC antigen in mice. These results suggest that expression and delivery of heterologous antigens fused to the N-terminus of SipB enhance the induction of antigen-specific immune responses, and that the N-terminal domain of SipB can be used as a versatile delivery system for foreign antigens.

Molecular characterization of the InvE regulator in the secretion of type III secretion translocases in Salmonella enterica serovar Typhimurium

The type III secretion systems (T3SSs) are exploited by many Gram-negative pathogenic bacteria to deliver a set of effector proteins into the host cytosol during cell entry. The T3SS of Salmonella enterica serovar Typhimurium is composed of more than 20 proteins that constitute the membrane-associated base, the needle and the tip complex at the distal end of the T3SS needle. Membrane docking and piercing between the T3SS and host cells is followed by the secretion of effector proteins. Therefore, a secretion hierarchy among the substrates of the T3SS is required. The secretion of the pore-forming translocase proteins SipB, SipC and SipD is controlled by the T3SS regulator protein, InvE. During an attempt to identify the regions of InvE that are involved in T3SS regulation, it was observed that the secretion of SipB, SipC and SipD was inhibited when the C-terminal 52 amino acids were removed from InvE. In addition, InvE derivatives lacking the N-terminal 30 and 100 residues were unable to secrete translocases into the culture medium. Interestingly, in the absence of the N-terminal 180 residues of InvE, SipD is unstable, resulting in the hypersecretion of SipB. We also found that both the type III secretion signals of SipB and SptP were functionally interchangeable with the first 30 amino acids of InvE, which could allow the secretion of a reporter protein. These results indicate that InvE may have two functional domains responsible for regulating the secretion of translocases: an N-terminal secretion signal and a C-terminal regulatory domain.

A phosphotransferase system permease is a novel component of CadC signaling in Salmonella enterica

In Salmonella enterica serovar Typhimurium, proteolytic cleavage of the membrane-bound transcriptional regulator CadC acts as a switch to activate genes of the lysine decarboxylase system in response to low pH and lysine signals. To identify the genetic factors required for the proteolytic activation of CadC, we performed genome-wide random mutagenesis. We show that a phosphotransferase system (PTS) permease STM4538 acts as a positive modulator of CadC function. The transposon insertion in STM4538 reduces the expression of the CadC target operon cadBA under permissive conditions. In addition, deletional inactivation of STM4538 in the wild-type background leads to the impaired proteolytic cleavage of CadC. We also show that only the low pH signal is involved in the proteolytic processing of CadC, but the lysine signal plays a role in the repression of the lysP gene encoding a lysine-specific permease, which negatively controls expression of the cadBA operon. Our data suggest that the PTS permease STM4538 affects proteolytic processing, which is a necessary but not sufficient step for CadC activation, rendering CadC able to activate target genes.

Usefulness of the Pinch-Burn-Cut (PBC) technique for recipient hepatectomy in liver transplantation

BACKGROUNDS/AIMS

Surgical bleeding during recipient hepatectomy is a major concern in liver transplantation (LT). Effective intraoperative control of bleeding is necessary. In the Pinch-Burn-Cut (PBC) technique, a small amount of tissue around the dissection plane is pinched with forceps, electocauterized and gently cut. The present study sought to estimate the usefulness of the PBC technique in LT.

METHODS

Between June 2007 and December 2010, 123 adult cases underwent LT in our center. Of these, 72 involved a recipient hepatectomy using the PBC technique (PBC group). and 51 involved the conventional technique (non-PBC group). Clinical parameters were compared between two groups.

RESULTS

The amount of blood loss and related transfusions were significantly reduced, and the operating time was shorter in the PBC group than in the non-PBC group (p=0.006, p<0.05 and p=0.002, respectively). There was also shorter duration of mechanical ventilation after LT in the PBC group (p=0.017). The incidence of postoperative hemorrhage was lower in the PBC group than in the non-PBC group, but had no statistical significance between two group (19.6% vs. 8.3%, p=0.101).

CONCLUSIONS

Our data suggest that the PBC technique is effective for bleeding control during recipient hepatectomy in LT.

Suppression of inflammation by recombinant Salmonella typhimurium harboring CCL22 microRNA

Atopic dermatitis (AD) is an inflammatory, chronically relapsing, puritic skin disorder. These syndromes result from multifactorial inheritance, with interaction between genetic and environmental factors. In particular, the macrophage-derived chemokine CCL22 is directly implicated in skin inflammatory reactions and its levels are significantly elevated in serum and correlated with disease severity in AD. We tested the suppression of the CCL22 gene by microRNA (miRNA) and observed the effects in mice with inflammation similar to AD. We used Salmonella as a vector to deliver miRNA. The recombinant strain of Salmonella typhimurium expressing CCL22 miRNA (ST-miRCCL22) was prepared for in vivo knockdown of CCL22. ST-miRCCL22 was orally inoculated into mice and the CCL22 gene suppressed with CCL22 miRNA in the activated lymphocytes. IgE and interleukin-4 were inhibited and interferon-γ was induced after treatments with ST-miRCCL22 and CCL22 was suppressed. Further, Th17 cells were suppressed in the atopic mice treated with ST-miRCCL22. These results suggested that suppression of the CCL22 gene using Salmonella induced anti-inflammatory effects.

Therapeutic effects of recombinant Salmonella typhimurium harboring CCL22 miRNA on atopic dermatitis-like skin in mice

Th-2-biased immune responses are known to play a key role in the pathogenesis of atopic dermatitis. In particular, the macrophage-derived chemokine CCL22 is directly implicated in Th-2-associated skin inflammatory reactions, and its levels are significantly elevated in serum and are correlated with disease severity in atopic dermatitis. In this study, we tested the development of genetic therapeutic options to treat atopic dermatitis using bacteria expressing miRNA. We constructed a recombinant strain of Salmonella typhimurium expressing CCL22 miRNA (ST-miRCCL22) for the in vivo knockdown of CCL22. The CCL22 gene was downregulated with CCL22 miRNA in activated lymphocytes. In mice with a cutaneous disease similar to atopic dermatitis, interleukin-4 was inhibited and interferon-g was induced after treatments with ST-miRCCL22. Furthermore, CCL22 levels were suppressed in the atopic mice treated with ST-miRCCL22. These results suggest that ST-miRCCL22 may be an effective genetic agent for treating atopic dermatitis.

Salmonella typhimurium harboring plasmid expressing interleukin-12 induced attenuation of infection and protective immune responses

IL-12 is known to be an essential cytokine which appears to provide protective immunity against intracellular bacteria, such as Salmonella. In this study, we investigated the possibility of developing a vaccine using IL-12 against virulent Salmonella. We used the host defense system activated by cytokine IL-12. The highly virulent Salmonella strain (Salmonella typhimurium UK-1) was transformed with cytokine-expressing plasmids. These live, wild-type pathogens were used as vaccine strains without undergoing any other biological or genetic attenuating processes. The newly developed strains induced partial protection from infections (30-40%). Of note, the interleukin-12-transformed pathogen was safe upon immunization with low doses (10(3) cfu), induced IgG responses, and stimulated protective immune responses against Salmonella typhimurium in mice (80-100%). These results suggest that IL-12 induced attenuation of wild-type Salmonella in the host infection stage and vaccine development using the wild-type strain harboring plasmid-secreting IL-12 may be considered as an alternative process for intracellular bacterial vaccine development without the inconvenience of time-consuming attenuation processes.

Inhibition of a prolyl hydroxylase domain (PHD) by substrate analog peptides

Oxygen dependent degradation of hypoxia-inducible factor (HIF)-1α is triggered with hydroxylation by proline hydroxylase domain 2 (PHD2) under normoxic conditions. Some of previously developed PHD2 inhibitors show a considerable potency against factor inhibiting HIF (FIH), the HIF asparagine hydroxylase. For specific inhibition of PHD2, we have synthesized peptides containing 556-575 residues of HIF-1α with modifications at the Pro-564 and examined their inhibitory effect against PHD2. Adopting fluorescence polarization-based assays, we evaluated inhibitory potency of the peptides and selected potent inhibitors. These PHD2 inhibitor peptides showed no significant potency against FIH, demonstrating their specific inhibitory effect on PHD2.