Longitudinal long term follow up investigation on the carcinogenic impact of polyhexamethylene guanidine phosphate in rat models

Polyhexamethylene guanidine phosphate (PHMG-p) is a major component in humidifier disinfectants, which cause life-threatening lung injuries. However, to our knowledge, no published studies have investigated associations between PHMG-p dose and lung damage severity with long-term follow-up. Therefore, we evaluated longitudinal dose-dependent changes in lung injuries using repeated chest computed tomography (CT). Rats were exposed to low (0.2 mg/kg, n = 10), intermediate (1.0 mg/kg, n = 10), and high (5.0 mg/kg, n = 10) doses of PHMG-p. All rats underwent repeated CT scans after 10 and 40 weeks following the first exposure. All CT images were quantitatively analyzed using commercial software. Inflammation/fibrosis and tumor counts underwent histopathological evaluation. In both radiological and histopathologic results, the lung damage severity increased as the PHMG-p dose increased. Moreover, the number, size, and malignancy of the lung tumors increased as the dose increased. Bronchiolar-alveolar hyperplasia developed in all groups. During follow-up, there was intergroup variation in bronchiolar-alveolar hyperplasia progression, although bronchiolar-alveolar adenomas or carcinomas usually increase in size over time. Thirty-three carcinomas were detected in the high-dose group in two rats. Overall, lung damage from PHMG-p and the number and malignancy of lung tumors were shown to be dose-dependent in a rat model using repeated chest CT scans during a long-term follow-up.

Intrahospital transmission and infection control of Candida auris originating from a severely infected COVID-19 patient transferred abroad

BACKGROUND

Intrahospital spread of Candida auris, which survives tenaciously in many environments, can cause sustained colonization and infection. A large outbreak of C. auris was experienced in the intensive care units (ICUs) at the study hospital during the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

The index patient with severe COVID-19, who was transferred from Vietnam in January 2022, developed C. auris candidaemia 10 days after hospitalization. From mid-June 2022 to January 2023, strengthened infection prevention and control (IPC) measures were implemented in three ICUs: (1) contact precautions and isolation (CPI) for C. auris-positive cases; (2) surveillance cultures including point-prevalence (N=718) for patients or close contacts or ICU-resident healthcare workers (HCWs); (3) intensive environmental disinfection with 10-fold diluted bleach; and (4) 2% chlorhexidine bathing for all ICU patients. Environmental cultures (ECx) on surfaces and shared objects (N=276) were conducted until early September 2022, when all ECx were negative.

RESULTS

Among 53 C. auris-positive patients between February 2022 and January 2023, invasive infections resulted in seven cases of candidaemia and one case of pneumonia. C. auris was isolated from reusable tympanic thermometers (TTMs) contaminated with earwax. The isolation rate of C. auris in ECx decreased from 6.8% in June 2022 to 2.0% in August 2022, and was no longer detected in TTMs. Colonization in HCWs was remarkably rare (0.5%). The number of C. auris-positive patients peaked in July (N=10) then decreased gradually. By January 2023, no C. auris were isolated in the ICU.

CONCLUSION

Aggressive IPC measures with CPI, ECx and surveillance, decontamination of TTMs, and bathing were effective in successfully controlling this C. auris outbreak.

Multifunctional Intelligent Wearable Devices Using Logical Circuits of Monolithic Gold Nanowires

Although multifunctional wearable devices have been widely investigated for healthcare systems, augmented/virtual realities, and telemedicines, there are few reports on multiple signal monitoring and logical signal processing by using one single nanomaterial without additional algorithms or rigid application-specific integrated circuit chips. Here, multifunctional intelligent wearable devices are developed using monolithically patterned gold nanowires for both signal monitoring and processing. Gold bulk and hollow nanowires show distinctive electrical properties with high chemical stability and high stretchability. In accordance, the monolithically patterned gold nanowires can be used to fabricate the robust interfaces, programmable sensors, on-demand heating systems, and strain-gated logical circuits. The stretchable sensors show high sensitivity for strain and temperature changes on the skin. Furthermore, the micro-wrinkle structures of gold nanowires exhibit the negative gauge factor, which can be used for strain-gated logical circuits. Taken together, this multifunctional intelligent wearable device would be harnessed as a promising platform for futuristic electronic and biomedical applications.

Particulate matter induces arrhythmia-like cardiotoxicity in zebrafish embryos by altering the expression levels of cardiac development- and ion channel-related genes

Air pollution is a risk factor that increases cardiovascular morbidity and mortality. In this study, we investigated the cardiotoxicity of particulate matter (PM) exposure using a zebrafish embryo model. We found that PM exposure induced cardiotoxicity, such as arrhythmia, during cardiac development. PM exposure caused cardiotoxicity by altering the expression levels of cardiac development (T-box transcription factor 20, natriuretic peptide A, and GATA-binding protein 4)- and ion-channel (scn5lab, kcnq1, kcnh2a/b, and kcnh6a/b)-related genes. In conclusion, this study showed that PM induces the aberrant expression of cardiac development- and ion channel-related genes, leading to arrhythmia-like cardiotoxicity in zebrafish embryos. Our study provides a foundation for further research on the molecular and genetic mechanisms of cardiotoxicity induced by PM exposure.

Supramolecular Hydrogels for Precisely Controlled Antimicrobial Peptide Delivery for Diabetic Wound Healing

Diabetic wound patients are often exposed to bacterial infections with delayed healing process due to hyperglycemia in the damaged skin tissue. Antimicrobial peptides (AMPs) have been investigated for the treatment of infection-induced diabetic wounds, but their low stability and toxicity have limited their further applications to diabetic chronic wound healing. Here, we developed a precisely controlled AMP-releasing injectable hydrogel platform, which could respond to infection-related materials of matrix metalloproteinases (MMPs) and reactive oxygen species (ROS). The injectable supramolecular hydrogel was prepared by the simple mixing of hyaluronic acid modified with cyclodextrin (HA-CD) and adamantane (Ad-HA). Ad-HA was conjugated with AMP via the cyclic peptide linker composed of MMP and ROS cleavable sequence (Ad-HA-AMP). Remarkably, only when the AMP-tethered hydrogel was exposed to both MMP and ROS simultaneously, AMP was released from the hydrogel, enabling the controlled release of AMP without causing cytotoxicity. In addition, we confirmed the enhanced serum stability of the Ad-HA-AMP conjugate. The antimicrobial activity of Ad-HA-AMP was maintained much longer than that of the native AMP. Finally, we could demonstrate the greatly improved wound-healing effect of AMP-tethered hydrogels with enhanced safety for the treatment of infection-induced diabetic chronic wounds. Taken together, we successfully demonstrated the feasibility of sHG-AMP for diabetic chronic wound healing.

Initial phase establishment of an in vitro method for developmental neurotoxicity test using Ki-67 in human neural progenitor cells

Building a precise alternative neurotoxicological test is of great importance to respond to societal and ethical requirements. In this study, a new developmental neurotoxicity test (DNT) was established with the human neural progenitor cell line. ReNcell CX cells were exposed to neurotoxic chemicals (aphidicolin, hydroxyurea, cytosine arabinoside, 5-fluorouracil, and ochratoxin A) or non-neurotoxic chemicals (sodium gluconate, sodium bicarbonate, penicillin G, and saccharin). Propidium iodide (PI) was used to evaluate cell viability. BrdU and Ki-76 were employed to determine cell proliferation. Based on the cell viability and proliferation, mathematical models were built by linear discriminant analysis. Furthermore, the neurotoxic-considered chemicals inhibited cell cycle progression at the protein level, supporting the biomolecular rationale for the predictive model. Overall, these results show that the new test method can be used to determine the potential developmental neurotoxicants or new drug candidates.

Microalgae-Based Biohybrid Microrobot for Accelerated Diabetic Wound Healing

A variety of wound healing platforms have been proposed to alleviate the hypoxic condition and/or to modulate the immune responses for the treatment of chronic wounds in diabetes. However, these platforms with the passive diffusion of therapeutic agents through the blood clot result in the relatively low delivery efficiency into the deep wound site. Here, a microalgae-based biohybrid microrobot for accelerated diabetic wound healing is developed. The biohybrid microrobot autonomously moves at velocity of 33.3 µm s^-1 and generates oxygen for the alleviation of hypoxic condition. In addition, the microrobot efficiently bound with inflammatory chemokines of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) for modulating the immune responses. The enhanced penetration of microrobot is corroborated by measuring fibrin clots in biomimetic wound using microfluidic devices and the enhanced retention of microrobot is confirmed in the real wounded mouse skin tissue. After deposition on the chronic wound in diabetic mice without wound dressing, the wounds treated with microrobots are completely healed after 9 days with the significant decrease of inflammatory cytokines below 31% of the control level and the upregulated angiogenesis above 20 times of CD31⁺ cells. These results confirm the feasibility of microrobots as a next-generation platform for diabetic wound healing.

Hematotoxic Effect of Respiratory Exposure to PHMG-p and Its Integrated Genetic Analysis

Polyhexamethylene guanidine phosphate (PHMG-p), the main ingredient of humidifier disinfectants, circulates systemically through the lungs; however, its toxicological assessment has been primarily limited to pulmonary disease. Herein, we investigated the possible abnormalities in hematopoietic function 20 weeks after intratracheal instillation of PHMG-p in a rat model. Notable abnormalities were found out in the peripheral blood cell count and bone marrow (BM) biopsy, while RNA sequencing of BM tissue revealed markedly altered gene expression. Furthermore, signaling involved in hematopoietic dysfunction was predicted by analyzing candidate genes through Ingenuity Pathway Analysis (IPA) program. Respiratory PHMG-p exposure significantly decreased monocyte and platelet (PLT) counts and total protein, while significantly increasing hemoglobin and hematocrit levels in peripheral blood. Histopathological analysis of the BM revealed a reduced number of megakaryocytes, with no significant differences in spleen and liver weight to body weight. Moreover, PHMG-p exposure significantly activated estrogen receptor signaling and RHOA signaling, and inhibited RHOGDI signaling. In IPA analysis, candidate genes were found to be strongly related to 'hematological system development and function' and 'hematological disease.' Accordingly, our results suggest that PHMG-p could affect hematopoiesis, which participates in monocyte differentiation and PLT production, and may induce hematologic diseases via the respiratory tract.

Exposure to airborne particulate matter induces renal tubular cell injury in vitro: the role of vitamin D signaling and renin-angiotensin system

Background

Exposure to air pollution can interfere with the vitamin D endocrine system. This study investigated the effects of airborne particulate matter (PM) on renal tubular cell injury in vitro and explored the underlying mechanisms.

Methods

HK-2 human renal proximal tubule cells were treated with PM with or without 1,25(OH)₂D₃ analog, 19-Nor-1,25(OH)₂D₂ (paricalcitol, 10 nM) for 48 h. The dose- and time-dependent cytotoxicity of PM with or without paricalcitol was determined via cell counting kit-8 assay. Cellular oxidative stress was assessed using commercially available enzyme-linked immunosorbent assay kits. The protein expression of vitamin D receptor (VDR), cytochrome P450(CYP)27B1, CYP24A1, renin, angiotensin converting enzyme (ACE), angiotensin II type 1 receptor (AT1), nuclear factor erythroid 2-related factor 2 (Nrf2), nuclear factor-kB (NF-kB), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 was determined.

Results

PM exposure decreased HK-2 cell viability in a dose- and time-dependent manner. The activities of superoxide dismutase and malondialdehyde in HK-2 cells increased significantly in the group exposed to PM. PM exposure decreased VDR and Nrf2, while increasing CYP27B1, renin, ACE, AT1, NF-kB, TNF-α, and IL-6. The expression of VDR, CYP27B1, renin, ACE, AT1, and TNF-α was reversed by paricalcitol treatment. Paricalcitol also restored the cell viability of PM-exposed HK-2 cells.

Conclusion

Our findings indicate that exposure to PM induces renal proximal tubular cell injury, concomitant with alteration of vitamin D endocrine system and renin angiotensin system. Vitamin D could attenuate renal tubular cell damage following PM exposure by suppressing the renin-angiotensin system and by partially inhibiting the inflammatory response.

Analysis of lung cancer-related genetic changes in long-term and low-dose polyhexamethylene guanidine phosphate (PHMG-p) treated human pulmonary alveolar epithelial cells

BACKGROUND

Lung injury elicited by respiratory exposure to humidifier disinfectants (HDs) is known as HD-associated lung injury (HDLI). Current elucidation of the molecular mechanisms related to HDLI is mostly restricted to fibrotic and inflammatory lung diseases. In our previous report, we found that lung tumors were caused by intratracheal instillation of polyhexamethylene guanidine phosphate (PHMG-p) in a rat model. However, the lung cancer-related genetic changes concomitant with the development of these lung tumors have not yet been fully defined. We aimed to discover the effect of long-term exposure of PHMG-p on normal human lung alveolar cells.

METHODS

We investigated whether PHMG-p could increase distorted homeostasis of oncogenes and tumor-suppressor genes, with long-term and low-dose treatment, in human pulmonary alveolar epithelial cells (HPAEpiCs). Total RNA sequencing was performed with cells continuously treated with PHMG-p and harvested after 35 days.

RESULTS

After PHMG-p treatment, genes with transcriptional expression changes of more than 2.0-fold or less than 0.5-fold were identified. Within 10 days of exposure, 2 protein-coding and 5 non-coding genes were selected, whereas in the group treated for 27-35 days, 24 protein-coding and 5 non-coding genes were identified. Furthermore, in the long-term treatment group, 11 of the 15 upregulated genes and 9 of the 14 downregulated genes were reported as oncogenes and tumor suppressor genes in lung cancer, respectively. We also found that 10 genes of the selected 24 protein-coding genes were clinically significant in lung adenocarcinoma patients.

CONCLUSIONS

Our findings demonstrate that long-term exposure of human pulmonary normal alveolar cells to low-dose PHMG-p caused genetic changes, mainly in lung cancer-associated genes, in a time-dependent manner.

Pulmonary fibrosis model using micro-CT analyzable human PSC-derived alveolar organoids containing alveolar macrophage-like cells

Human lung organoids (hLOs) are useful for disease modelling and drug screening. However, a lack of immune cells in hLOs limits the recapitulation of in vivo cellular physiology. Here, we generated hLOs containing alveolar macrophage (AMφ)–like cells derived from pluripotent stem cells (PSC). To bridge hLOs with advanced human lung high-resolution X-ray computed tomography (CT), we acquired quantitative micro-CT images. Three hLO types were observed during differentiation. Among them, alveolar hLOs highly expressed not only lung epithelial cell markers but also AMφ-specific markers. Furthermore, CD68⁺ AMφ-like cells were spatially organized on the luminal epithelial surface of alveolar hLOs. Bleomycin-treated alveolar hLOs showed upregulated expression of fibrosis-related markers and extracellular matrix deposits in the alveolar sacs. Alveolar hLOs also showed structural alterations such as excessive tissue fraction under bleomycin treatment. Therefore, we suggest that micro-CT analyzable PSC-derived alveolar hLOs are a promising in vitro model to predict lung toxicity manifestations, including fibrosis.

Supramolecular host-guest hyaluronic acid hydrogels enhance corneal wound healing through dynamic spatiotemporal effects

Severe corneal wounds can lead to ulceration and scarring if not promptly and adequately treated. Hyaluronic acid (HA) has been investigated for the treatment of corneal wounds due to its remarkable biocompatibility, transparency and mucoadhesive properties. However, linear HA has low retention time on the cornea while many chemical moieties used to crosslink HA can cause toxicity, which limits their clinical ocular applications. Here, we used supramolecular non-covalent host-guest interactions between HA-cyclodextrin and HA-adamantane to form shear-thinning HA hydrogels and evaluated their impact on corneal wound healing. Supramolecular HA hydrogels facilitated adhesion and spreading of encapsulated human corneal epithelial cells ex vivo and improved corneal wound healing in vivo as an in situ-formed, acellular therapeutic membrane. The HA hydrogels were absorbed within the corneal stroma over time, modulated mesenchymal cornea stromal cell secretome production, reduced cellularity and inflammation of the anterior stroma, and significantly mitigated corneal edema compared to treatment with linear HA and untreated control eyes. Taken together, our results demonstrate supramolecular HA hydrogels as a promising and versatile biomaterial platform for corneal wound healing.

Spontaneous Disappearance of Unruptured Intracranial Aneurysm: A Case Report

Spontaneous resolution or thrombosis of giant or ruptured intracranial aneurysms is occasionally reported. However, spontaneous resolution of unruptured aneurysms without any intervention is extremely rare. Recently, we encountered a case of spontaneous resolution of a small unruptured aneurysm of the anterior communicating artery. We describe this rare case and discuss the mechanism of resolution with a review of the related literature.

Bioinspired urease-powered micromotor as an active oral drug delivery carrier in stomach

Self-propelling micro- and nano-motors (MNMs) have been extensively investigated as an emerging oral drug delivery carrier for gastrointestinal (GI) tract diseases. However, the propulsion of current MNMs reported so far is mostly based on the redox reaction of metals (such as Zn and Mg) with severe propulsion gas generation, remaining non-degradable residue in the GI tract. Here, we develop a bioinspired enzyme-powered biopolymer micromotor mimicking the mucin penetrating behavior of Helicobacter pylori in the stomach. It converts urea to ammonia and the subsequent increase of pH induces local gel-sol transition of the mucin layer facilitating the penetration into the stomach tissue layer. The successful fabrication of micromotors is confirmed by high-resolution transmission electron microscopy, electron energy loss spectroscopy, dynamic light scattering analysis, zeta-potential analysis. In acidic condition, the immobilized urease can efficiently converted urea to ammonia, comparable with that of neutral condition because of the increase of surrounding pH during propulsion. After administration into the stomach, the micromotors show enhanced penetration and prolonged retention in the stomach for 24 h. Furthermore, histological analysis shows that the micromotors are cleared within 3 days without causing any toxicity in the GI tract. The enhanced penetration and retention of the micromotors as an active oral delivery carrier in the stomach would be successfully harnessed for the treatment of various GI tract diseases.

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Polydopamine (PDA) hollow microcapsules are biocompatible, biodegradable, and muco-adhesive.

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Urease-powered PDA micromotors are propelled by the decomposition of urea to ammonia and carbon dioxide.

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Micromotors increase the local pH to induce the gel-sol transition of the mucus layer.

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Micromotors result in enhanced penetration and prolonged retention in the stomach.

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Micromotors can be effectively used for oral drug delivery with complete clearance from the GI tract.

Evaluation of the effect of filtered ultrafine particulate matter on bleomycin-induced lung fibrosis in a rat model using computed tomography, histopathologic analysis, and RNA sequencing

We aimed to investigate the effect of chronic particulate matter (PM) exposure on bleomycin-induced lung fibrosis in a rat model using chest CT, histopathologic evaluation, and RNA-sequencing. A bleomycin solution was intratracheally administrated to 20 male rats. For chronic PM exposure, after four weeks of bleomycin treatment to induce lung fibrosis, PM suspension (experimental group) or normal saline (control group) was intratracheally administrated for 10 weeks. Chest CT was carried out in all rats, and then both lungs were extracted for histopathologic evaluation. One lobe from three rats in each group underwent RNA sequencing, and one lobe from five rats in each group was evaluated by western blotting. Inflammation and fibrosis scores in both chest CT and pathologic analysis were significantly more aggravated in rats with chronic PM exposure than in the control group. Several genes associated with inflammation and immunity were also upregulated with chronic PM exposure. Our study revealed that chronic PM exposure in a bleomycin-induced lung fibrosis rat model aggravated pulmonary fibrosis and inflammation, proven by chest CT, pathologic analysis, and RNA sequencing.

Evaluation of the long-term effect of polyhexamethylene guanidine phosphate in a rat lung model using conventional chest computed tomography with histopathologic analysis

There have been no studies on the effects of polyhexamethylene guanidine phosphate (PHMG) after a long period of exposure in the rodent model. We aimed to evaluate long-term lung damage after PHMG exposure using conventional chest computed tomography (CT) and histopathologic analysis in a rat model. A PHMG solution was intratracheally administrated to 24 male rats. At 8, 26, and 52 weeks after PHMG instillation, conventional chest CT was performed in all rats and both lungs were extracted for histopathologic evaluation. At 52 weeks after PHMG instillation, four carcinomas had developed in three of the eight rats (37.5%). Bronchiolo-alveolar hyperplasia and adenoma were found in rats at 8, 26, and 52 weeks post-instillation. The number of bronchiolo-alveolar hyperplasia significantly increased over time (P-value for trend< 0.001). The severity of lung fibrosis and fibrosis scores significantly increased over time (P-values for trend = 0.002 and 0.023, respectively). Conventional chest CT analysis showed that bronchiectasis and linear density scores suggestive of fibrosis significantly increased over time (P-value for trend < 0.001). Our study revealed that one instillation of PHMG in a rat model resulted in lung carcinomas and progressive and irreversible fibrosis one year later based on conventional chest CT and histopathologic analysis. PHMG may be a lung carcinogen in the rat model.

STAT3 maintains skin barrier integrity by modulating SPINK5 and KLK5 expression in keratinocytes

Skin barrier dysfunction induces skin inflammation. Signal transducer and activator of transcription 3 (STAT3) is known to be involved in Th17-mediated immune responses and barrier integrity in the cornea and intestine; however, its role in the skin barrier remains largely unknown. In this study, we elucidated the potential role of STAT3 in the skin barrier and its effect on kallikrein-related peptidase 5 (KLK5) and serine protease inhibitor Kazal-type 5 (SPINK5) expression using a mouse model with keratinocyte-specific ablation of STAT3. Keratinocyte-specific loss of STAT3 induced a cutaneous inflammatory phenotype with pruritus and intense scratching behaviour in mice. Transcriptomic analysis revealed that the genes associated with impaired skin barrier function, including KLK5, were upregulated. The effect of STAT3 on KLK5 expression in keratinocytes was not only substantiated by the increase in KLK5 expression following treatment with STAT3 siRNA but also by its decreased expression following STAT3 overexpression. Overexpression and IL-17A-mediated stimulation of STAT3 increased the expression of SPINK5, which was blocked by STAT3 siRNA. These results suggest that the expression of SPINK5 and KLK5 in keratinocytes could be dependent on STAT3 and that STAT3 might play an essential role in the maintenance of skin barrier homeostasis.

First line Treatment of Traumatic Carotid Cavernous Fistulas Using Covered Stents at Level 1 Regional Trauma Center

Objective

The widely accepted treatment option of a traumatic carotid cavernous fistula (TCCF) has been detachable balloon or coils based fistula occlusion. Recently, covered stent implantation has been proving an excellent results. The purpose of this study is to investigate our experiences with first line choice of covered stent implantation for TCCF at level 1 regional trauma center.

Methods

From November 2004 to February 2020, 19 covered stents were used for treatment of 19 TCCF patients. Among them, 15 cases were first line treatment using covered stents. Clinical and angiographic data were retrospectively reviewed.

Results

Procedures were technically successful in all 15 cases (100%). Immediate angiographic results after procedure were total occlusion in 12 patients (80%). All patients except two expired patients had image follow-up (mean 15 months). Recurred symptomatic three patients underwent additional treatments and achieved complete occlusion. Mean clinical follow-up duration was 32 months and results were modified Rankin Scale 1–2 in five, 3–4 in five, and 5 in three patients.

Conclusion

The covered stent could be considered as fist line treatment option for treating TCCF patients especially in unstable vital sign. Larger samples and expanded follow-up are required to further develop their specifications and indications.

Biomimetic Supramolecular Drug Delivery Hydrogels for Accelerated Skin Tissue Regeneration

Skin tissue is regenerated by the combinational function of skin cells, extracellular matrix (ECM), and bioactive molecules. As an artificial ECM, supramolecular hydrogels exhibited outstanding capability to mimic the physical properties of ECM. However, the lack of biochemical function in supramolecular hydrogels has limited further tissue engineering applications. Here, we developed self-assembling supramolecular drug delivery hydrogels to mimic the skin tissue regeneration process. The supramolecular hydrogels were prepared to encapsulate fibroblasts by the host-guest interaction of cyclodextrin-modified gelatin (GE-CD) and adamantane-modified hyaluronate (Ad-HA) in conjugation with human growth hormone (hGH) for accelerated skin tissue regeneration. In vitro, GE-CD/Ad-HA-hGH hydrogels showed highly facilitated cell growth by the controlled hGH delivery. After a subcutaneous injection into the back of mice, IVIS imaging of bioengineered fibroblasts to express red fluorescence protein (RFP) revealed prolonged cell survival and proliferation in the supramolecular hydrogels for more than 21 days. We could also observe the improved skin tissue regeneration by the facilitated fibroblast proliferation with angiogenesis. Taken together, we could confirm the feasibility of biomimetic supramolecular drug delivery GE-CD/Ad-HA-hGH hydrogels for various tissue engineering applications.

Smart Contact Lenses with a Transparent Silver Nanowire Strain Sensor for Continuous Intraocular Pressure Monitoring

Continuous intraocular pressure (IOP) monitoring can provide a paradigm shift in the management of patients with glaucoma as a facile alternative to conventional diagnostic methods. However, the low sensitivity and functional instability of current IOP sensors have limited their clinical utility in the management of glaucoma. Here, we have developed a smart contact lens integrated with a transparent silver nanowire IOP strain sensor and wireless circuits for noninvasive, continuous IOP monitoring. After confirming the robust stability of the IOP sensor within the smart contact lens in the presence of tears and repeated eyelid blink model cycles, we were able to monitor IOP changes on polydimethylsiloxane model eyes in vitro. In vivo tests demonstrated that our fully integrated wireless smart contact lens could successfully monitor the change in IOP in living rabbit eyes, which was clearly validated by the conventional invasive tonometer IOP test. Taken together, we could confirm the feasibility of our smart contact lens as a noninvasive platform for continuous IOP monitoring of glaucoma patients.

Exacerbation of symptomatic arthritis by cigarette smoke in experimental arthritis

Introduction

Epidemiologically, cigarette smoking is a well-known risk factor for the pathogenesis of rheumatoid arthritis (RA). However, there has been few plausible explanations why cigarette smoking aggravated RA. We investigated the causal effect of smoking in experimental model of arthritis development.

Methods

During induction of experimental arthritis with collagen challenge, mice were exposed to a smoking environment with 3R4F cigarettes. Generated smoke was delivered to mice through a nose-only exposure chamber (ISO standard 3308). Human cartilage pellet was challenged by cigarette smoke extract to identify citrullinating potential in vitro.

Results

Cigarette smoke exacerbated arthritis in a collagen-induced arthritis (CIA) model. Exposure to smoke accelerated the onset of arthritis by 2 weeks compared to the conventional model without smoke. Citrullination of lung tissue as well as tarsal joints were revealed in smoke-aggravated CIA mice. Interestingly, tracheal cartilage was a core organ regarding intensity and area size of citrullination. The trachea might be an interesting organ in viewpoint of sharing cartilage with joint and direct smoke exposure. Anti-CCP antibodies were barely detected in the serum of CIA mice, they were significantly elevated in cigarette smoke group. Citrullinated antigens were increased in the serum of smoke-exposed mice. Lastly, a cigarette smoke extract enhanced human cartilage citrullination in vitro.

Conclusions

Missing link of arthritic mechanism between smoke and RA could be partially explained by tracheal citrullination. To control tracheal cartilage citrullination may be beneficial for preventing arthritis development or aggravation if cigarette smoke is becoming a risk factor to pre-arthritic individual.

Clinical features and prognosis of patients with idiopathic pulmonary fibrosis and chronic obstructive pulmonary disease

<sec> <title>BACKGROUND</title> Idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD) share common risk factors. They could therefore be expressed in a single patient. However, the prevalence, clinical characteristics and prognosis of individuals with comorbid IPF and COPD are not known. </sec> <sec> <title>METHOD</title> From 2003 to 2007, the Korean Interstitial Lung Disease Study Group created a register for idiopathic interstitial pneumonia using 2002 ATS/ERS (American Thoracic Society/European Respiratory Society) criteria. Of the 1546 IPF patients assessed, 143 had decreased lung function consistent with COPD (IPF-COPD). COPD was diagnosed based on age (≥40 years) and pulmonary function (forced expiratory volume in 1 sec [FEV₁]/forced vital capacity [FVC] ratio < 0.7). </sec> <sec> <title>RESULTS</title> The median age of the IPF-COPD group was 71.0 years (interquartile range 66.0-76.0); most patients were male (88.1%). FVC (%) was significantly higher in the IPF-COPD group; however, FEV₁ (%) was significantly lower in the IPF-COPD group (P < 0.001). Diffusing capacity of the lung for carbon monoxide (DL_CO) was not significantly different between the two groups. In survival analysis, age and FVC (%), but not COPD, were significantly associated with prognosis (respectively P = 0.003, 0.001 and 0.401). COPD severity was also not related to prognosis (P = 0.935). </sec> <sec> <title>CONCLUSION</title> The prevalence of IPF-COPD was estimated to be ∼9.2% among all IPF patients; prognosis of patients with IPF-COPD was not worse than those with IPF alone. </sec>.

Electronic structure, thermodynamic stability and high-temperature sensing properties of Er-α-SiAlON ceramics

α-SiAlON ceramics have been in use as engineering ceramics in the most arduous industrial environments such as molten metal handling, cutting tools, gas turbine engines, extrusion molds, thermocouple sheaths, protective cover for high-temperature sensors, etc., owing to their outstanding mechanical, thermal and chemical stability. Taking advantage of the intrinsic properties of α-SiAlONs, we investigate, in this paper, the possibility of using the Er-doped α-SiAlON (Er-α-SiAlON) ceramic as a high-temperature sensing material via its unique near-infrared to visible upconversion property. We first use neutron diffraction and density functional theory calculations to study the electronic structure and thermodynamic stability of Er-α-SiAlON. It is found that the interstitial doping of Er stabilizes the α-SiAlON structure via chemical bonds with O-atoms with N:O ratio of 5:2 in the seven-fold coordination sites of the Er3+ ion. Temperature-dependent upconversion emissions are then studied under 980 and 793 nm excitations over a temperature range of 298-1373 K and the fluorescence intensity ratio (FIR) technique has been employed to investigate the temperature sensing behavior. Temperature-dependent Raman behavior is also investigated. We demonstrate that using Er-α-SiAlON as a sensing material, the limit of temperature measurement via the FIR technique can be pushed well beyond 1200 K.

HIF-1α-mediated BMP6 down-regulation leads to hyperproliferation and abnormal differentiation of keratinocytes in vitro

Hypoxia-inducible factor-1α (HIF-1α) has been reported to be up-regulated in psoriatic epidermis, resulting in increased proliferation and abnormal differentiation of human keratinocytes (KCs). However, the role of HIF-1α in psoriatic epidermis, which is mainly composed of KCs, is poorly understood. Here, we show that morphogenic protein 6 (BMP6) is down-regulated when HIF-1α is upregulated in patients with psoriasis skin lesions. HIF-1α overexpression in primary human KCs promoted proliferation and inhibited terminal differentiation. Furthermore, HIF1-α repressed the expression of BMP6 by binding directly to the hypoxia-response element (HRE) in the BMP6 promotor region, which shows that BMP6 is a novel target gene of HIF-1α. We also found that HIF-1α-mediated BMP6 suppression could alter the proliferation status by modulating the expression levels of cell cycle regulatory proteins and also affect the early differentiation of KCs. Therefore, we suggest that HIF-1α-dependent BMP6 suppression has a critical role in the induction of hyper-proliferation and abnormal differentiation in psoriatic KCs.

Silver nanoparticles induce Egr-1-dependent psoriasin expression via the ERK and p38 pathways

BACKGROUND

Silver nanoparticles (Ag-NPs) can prevent bacterial infection and improve cutaneous wound healing owing to their antimicrobial activity. However, the mechanism of their antimicrobial activity is poorly understood.

AIM

To determine the mechanistic relationship between Ag-NP treatment and expression of psoriasin.

METHODS

Human epidermal keratinocytes, neonatal (HEKn) were used. Psoriasin mRNA expression was measured by reverse transcription PCR and real-time PCR. Western blotting was performed to verify expression of early growth response-1 (Egr-1) and psoriasin, and phosphorylation of mitogen-activated protein kinase (MAPK). Psoriasin promoter activity by Egr-1 was detected by a luciferase assay.

RESULTS

Treatment of HEKn with Ag-NPs induced psoriasin mRNA and protein expression. Upregulation of psoriasin promoter activity was also observed in the luciferase assay. Ag-NPs increased Egr-1 expression, promoter activity and nuclear translocation in HEKn. Psoriasin luciferase activity was increased in HEKn transfected with Egr-1 pcDNA 3.1. Ag-NPs activated MAPK pathways including the extracellular signal-regulated kinase (ERK), p38, and c-Jun-N-terminal kinase (JNK) pathways. The upregulation of Egr-1 expression by Ag-NP stimulation was inhibited by ERK and p38 inhibitors, but not by a JNK inhibitor. Psoriasin expression was reduced in Egr-1 small interfering RNA-transfected HEKn.

CONCLUSIONS

Ag-NP treatment induces upregulation of psoriasin expression through Egr-1 expression. We suggest that the ERK and p38 pathways are involved in Egr-1-dependent psoriasin expression.

Interrupting oral infection of Porphyromonas gingivalis with anti-FimA antibody attenuates bacterial dissemination to the arthritic joint and improves experimental arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that typically results in strong inflammation and bone destruction in the joints. It is generally known that the pathogenesis of RA is linked to cardiovascular and periodontal diseases. Though rheumatoid arthritis and periodontitis share many pathologic features such as a perpetual inflammation and bone destruction, the precise mechanism underlying a link between these two diseases has not been fully elucidated. Collagen-induced arthritis (CIA) mice were orally infected with Porphyromonas gingivalis (Pg) or Pg preincubated with an anti-FimA antibody (FimA Ab) specific for fimbriae that are flexible appendages on the cell surface. Pg-infected CIA mice showed oral microbiota disruption and increased alveolar bone loss and had synovitis and joint bone destruction. However, preincubation with FimA Ab led to a significant reduction in the severity of both oral disease and arthritis. Moreover, FimA Ab attenuated bacterial attachment and aggregation on human gingival and rheumatoid arthritis synovial fibroblasts. In addition, we discovered bacteria may utilize dendritic cells, macrophages and neutrophils to migrate into the joints of CIA mice. These results suggest that disrupting Pg fimbriae function by FimA Ab ameliorates RA.

Intracellular ROS levels determine the apoptotic potential of keratinocyte by Quantum Dot via blockade of AKT Phosphorylation

Quantum dots (QDs) have shown great potential for biomedical use in a broad range including diagnostic agents. However, the regulatory mechanism of dermal toxicity is poorly understood. In this study, we investigated how QDs-induced apoptosis is regulated in human keratinocytes. We also examined the effect of carboxylic acid-coated QDs (QD 565 and QD 655) on reactive oxygen species (ROS) production and apoptosis-related cellular signalling. The viability of keratinocyte was inhibited by two types of QDs in a concentration-dependent manner. QDs induce ROS production and blockade of AKT phosphorylation. Moreover, the cleavage of AKT-dependent pro-apoptotic proteins such as poly (ADP-ribose) polymerase, caspases-3 and caspases-9 was significantly increased. We also found that a decrease in cellular ROS level by ROS scavenger, N-acetylcysteine (NAC), resulting in the abolishment of QDs-induced AKT de-phosphorylation and cellular apoptosis. Interestingly, QD 655 had a more cytotoxic effect including oxidative stress and AKT-dependent apoptosis than QD 565. In addition, QD 655 had the cytotoxic potential in the human skin equivalent model (HSEM). These data show that QD-induced intracellular ROS levels may be an important parameter in QD-induced apoptosis. These findings from this study indicate that intracellular ROS levels might determine the apoptotic potential of keratinocyte by QD via blockade of AKT phosphorylation.

Acute endophthalmitis after cataract surgery: 164 consecutive cases treated at a referral center in South Korea

PurposeTo identify prognostic factors in patients referred with endophthalmitis after cataract surgery, and to evaluate the efficacy of primary vitrectomy as an initial management.MethodsOver an eight-year study period, we retrospectively reviewed the medical records of 164 patients who were referred with endophthalmitis following cataract surgery. Treatment generally conformed to standard guidelines, although primary vitrectomy was performed in several eyes with a visual acuity of hand motion or better, depending on the patient's status. Using multivariate analysis, we analyzed outcomes to determine the effect on final visual outcome.ResultsA final visual acuity of ≥20/40 was achieved in 92/164 (56.1%) cases after treatment. Bacterial cultures showed bacterial growth in 89/164 cases (54.3%). Among the various baseline characteristics, old age (P=0.028), poor visual acuity at presentation (P=0.004), gram-negative bacterial infection (P=0.030), and short time between cataract surgery and signs of endophthalmitis (P=0.021) were associated with poor visual outcome. The visual outcome showed no significant difference, in terms of initial treatment feature, between the primary vitrectomy with intraocular antibiotics injection (IOAI) and IOAI-only groups. However, reintervention was significantly less frequent in the primary vitrectomy group than in the IOAI group (12.5 and 32.7%, respectively; P=0.002).ConclusionOld age, poor visual acuity at presentation, type of cultured organism (gram-negative bacteria), and early onset of endophthalmitis after cataract surgery were significantly related to poor visual outcome after endophthalmitis treatment. Primary vitrectomy may decrease the need for reintervention to control infection, although the treatment showed no benefits with regard to visual outcome.

Centrifugal gravity-induced BMP4 induces chondrogenic differentiation of adipose-derived stem cells via SOX9 upregulation

Background

Cartilage does not have the capability to regenerate itself. Therefore, stem cell transplantation is a promising therapeutic approach for impaired cartilage. For stem cell transplantation, in vitro enrichment is required; however, stem cells not only become senescent but also lose their differentiation potency during this process. In addition, cytokines are normally used for chondrogenic differentiation induction of stem cells, which is highly expensive and needs an additional step to culture. In this study, we introduced a novel method to induce chondrogenic differentiation of adipose-derived stem cells (ASCs), which are more readily available than bone marrow-derived mesenchymal stem cells(bMSCs), using centrifugal gravity (CG).

Methods

ASCs were stimulated by loading different degrees of CG (0, 300, 600, 1200, 2400, and 3600 g) to induce chondrogenic differentiation. The expression of chondrogenic differentiation-related genes was examined by RT-PCR, real-time PCR, and western blot analyses. The chondrogenic differentiation of ASCs stimulated with CG was evaluated by comparing the expression of positive markers [aggrecan (ACAN) and collagen type II alpha 1 (COL2A1)] and negative markers (COL1 and COL10) with that in ASCs stimulated with transforming growth factor (TGF)-β1 using micromass culture, immunofluorescence, and staining (Alcian Blue and Safranin O).

Results

Expression of SOX9 and SOX5 was upregulated by CG (2400 g for 30 min). Increased expression of ACAN and COL2A1 (positive markers) was detected in monolayer-cultured ASCs after CG stimulation, whereas that of COL10 (a negative marker) was not. Expression of bone morphogenetic protein (BMP) 4, an upstream stimulator of SOX9, was upregulated by CG, which was inhibited by Dorsomorphin (an inhibitor of BMP4). Increased expression of proteoglycan, a major component of cartilage, was confirmed in the micromass culture of ASCs stimulated with CG by Alcian Blue and Safranin O staining.

Conclusions

Chondrogenic differentiation of ASCs can be induced by optimized CG (2400 g for 30 min). Expression of SOX9 is upregulated by CG via increased expression of BMP4. CG has a similar ability to induce SOX9 expression as TGF-β1.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-016-0445-6) contains supplementary material, which is available to authorized users.

A phase 3b study of sofosbuvir plus ribavirin in treatment-naive and treatment-experienced Korean patients chronically infected with genotype 2 hepatitis C virus

In Korea, patients with chronic hepatitis C virus (HCV) infection are typically treated with pegylated interferon-alpha plus ribavirin, but interferons are contraindicated in many patients and are often poorly tolerated, particularly by the elderly and those with advanced liver disease. No interferon-free treatment regimens are approved in Korea. Sofosbuvir is an oral nucleotide analog inhibitor of the HCV nonstructural 5B RNA polymerase. It is approved in the USA, European Union and Japan for treating a number of HCV genotypes, including genotype 2. Genotype 2 has a seroprevalence of 38-46% in Korea. This single-arm, phase 3b study (NCT02021643) examined the efficacy and safety of sofosbuvir plus ribavirin (12-week duration) in chronic genotype 2 HCV-infected treatment-naive and treatment-experienced Korean patients with and without cirrhosis. The proportion of patients with sustained virologic response 12 weeks after treatment discontinuation (SVR12) was 97% (125/129), with 96% (101/105) of treatment-naive and 100% (24/24) of treatment-experienced patients achieving SVR12. Two patients experienced virologic failure (n = 1, on-treatment failure; n = 1, relapse). No patient discontinued study treatment due to an adverse event (AE). The most common treatment-emergent AEs were headache (18%, 23/129) and pruritus (15%, 19/129). Few patients had grade 3 AEs (5%, 6/129) or grade 3 laboratory abnormalities (12%, 15/129). No grade 4 AE was reported. These data suggest that 12 weeks of treatment with the all-oral, interferon-free regimen of sofosbuvir plus ribavirin is effective and well tolerated in Korean patients with chronic genotype 2 HCV infection.

Modification to the accelerator of the NBI-1B ion source for improving the injection efficiency

Minimizing power loss of a neutral beam imposes modification of the accelerator of the ion source for further improvement of the beam optics. The beam optics can be improved by focusing beamlets. The injection efficiencies by the steering of ion beamlets are investigated numerically to find the optimum modification of the accelerator design of the NBI-1B ion source. The beam power loss was reduced by aperture displacement of three edge beamlets arrays considering power loadings on the beamline components. Successful testing and operation of the ion source at 60 keV/84% of injection efficiency led to the possibility of enhancing the system capability to a 2.4 MW power level at 100 keV/1.9 μP.

A quantitative study of nanoparticle skin penetration with interactive segmentation

In the last decade, the application of nanotechnology techniques has expanded within diverse areas such as pharmacology, medicine, and optical science. Despite such wide-ranging possibilities for implementation into practice, the mechanisms behind nanoparticle skin absorption remain unknown. Moreover, the main mode of investigation has been qualitative analysis. Using interactive segmentation, this study suggests a method of objectively and quantitatively analyzing the mechanisms underlying the skin absorption of nanoparticles. Silica nanoparticles (SNPs) were assessed using transmission electron microscopy and applied to the human skin equivalent model. Captured fluorescence images of this model were used to evaluate degrees of skin penetration. These images underwent interactive segmentation and image processing in addition to statistical quantitative analyses of calculated image parameters including the mean, integrated density, skewness, kurtosis, and area fraction. In images from both groups, the distribution area and intensity of fluorescent silica gradually increased in proportion to time. Since statistical significance was achieved after 2 days in the negative charge group and after 4 days in the positive charge group, there is a periodic difference. Furthermore, the quantity of silica per unit area showed a dramatic change after 6 days in the negative charge group. Although this quantitative result is identical to results obtained by qualitative assessment, it is meaningful in that it was proven by statistical analysis with quantitation by using image processing. The present study suggests that the surface charge of SNPs could play an important role in the percutaneous absorption of NPs. These findings can help achieve a better understanding of the percutaneous transport of NPs. In addition, these results provide important guidance for the design of NPs for biomedical applications.

Role of protein kinase C-η in cigarette smoke extract-induced apoptosis in MRC-5-cells

Cigarette smoke (CS) is a major risk factor for emphysema, which causes cell death in structural cells of the lung by mechanisms that are still not completely understood. We demonstrated previously that CS extract (CSE) induces caspase activation in MRC-5 human lung fibroblasts, activated protein kinase C-η (PKC-η), and translocated PKC-η from the cytosol to the membrane. The objective of this study was to investigate the involvement of PKC-η activation in a CSE-induced extrinsic apoptotic pathway. We determined that CSE increases expression of caspase 3 and 8 cleavage in MRC-5 cells and overexpression of PKC-η significantly increased expression of caspase 3 and 8 cleavage compared with control LacZ-infected cells. In contrast, dominant negative (dn) PKC-η inhibited apoptosis in MRC-5 cells exposed to CSE and decreased expression of caspase 3 and 8 compared with control cells. Exposure to 10% CSE for >8 h significantly increased lactate dehydrogenase release in PKC-η-infected cells compared with LacZ-infected cells. Additionally, PKC-η-infected cells had an increased number of Hoechst 33342 stained nuclei compared with LacZ-infected cells, while dn PKC-η-infected cells exhibited fewer morphological changes than LacZ-infected cells under phase-contrast microscopy. In conclusion, PKC-η activation plays a pro-apoptotic role in CSE-induced extrinsic apoptotic pathway in MRC-5 cells. These results suggest that modulation of PKC-η may be a useful tool for regulating the extrinsic apoptosis of MRC-5 cells by CSE and may have therapeutic potential in the treatment of CS-induced lung injury.

Analysis of RAS mutation and PAX8/PPARγ rearrangements in follicular-derived thyroid neoplasms in a Korean population: frequency and ultrasound findings

OBJECTIVE

To investigate the frequency and ultrasonography (US) findings of RAS mutations and PAX8/PPARγ rearrangements between follicular thyroid adenomas (FTAs) and follicular thyroid carcinomas (FTCs) in a Korean population.

METHODS

RAS mutations and PAX8/PPARγ rearrangements in 56 FTAs and 35 FTCs were analyzed. We also analyzed the US findings of FTCs and FTAs.

RESULTS

16 nodules of 35 FTCs (45.7 %) and 19 nodules of 56 FTAs (33.9 %) harbored RAS mutations. Three FTCs and three FTAs showed two point mutations simultaneously. K-RAS codon 12-13 (n = 6, 31.6 %), N-RAS codon 61 (n = 5, 26.3 %), H-RAS codon 61 (n = 4, 21.1 %), K-RAS codon 61 (n = 3, 15.8 %), and N-RAS codon 12-13 (n = 1, 5.3 %) were found in FTCs, and N-RAS codon 61 (n = 10, 45 %), K-RAS codon 12-13 (n = 5, 22.7 %), H-RAS codon 61 (n = 5, 22.7 %), K-RAS codon 61 (n = 1, 4.5 %), and N-RAS codon 12-13 (n = 1, 4.5 %) were observed in FTAs. 4 of 56 (7.1 %) FTAs and 1 of 35 (2.9 %) FTCs represented PAX8/PPARγ rearrangements, respectively (P = 0.645). The absence of a hypoechoic rim (P = 0.021) and presence of calcifications (P = 0.049) were significantly associated with FTCs compared with FTAs.

CONCLUSIONS

RAS mutation frequency targeting the Korean population showed a 45.7 % in FTCs and 35.7 % in FTAs, and PAX8/PPARγ rearrangements were more frequently showed in FTAs. K-RAS codon 12-13 was the most common RAS mutation in FTCs, whereas N-RAS codon 61 was more frequent in FTAs. The presence of calcifications and absence of a hypoechoic rim showed more frequently in FTCs.

Egr-1 is a key regulator of IL-17A-induced psoriasin upregulation in psoriasis

The early growth response (Egr)-1 is a transcriptional factor which plays an important role in the regulation of cell growth, differentiation, cell survival and immune responses. Emerging evidences including our data demonstrate that the Egr-1 expression is up-regulated in the psoriatic skin lesions. The purpose of this study was to investigate the significance and regulatory mechanism of Egr-1 in the pathogenesis of psoriasis. Through microarray analysis, we found out that psoriasin (S100A7) expression was increased in the Egr-1 overexpressed cells. Our results showed that IL-17A increased Egr-1 expression in the skin of psoriatic patients and cultured human keratinocytes. We then investigated activation of mitogen-activated protein kinase as an upstream signal regulator of Egr-1 expression. IL-17A-induced Egr-1 expression was suppressed by ERK inhibitor. In addition, IL-17A induced psoriasin expression in cultured keratinocytes and the skin of IL-17A intradermally injected mouse. IL-17A-mediated psoriasin upregulation was reduced after treatment of small interfering RNAs against Egr-1. Furthermore, the results of chromatin immunoprecipitation assays demonstrated that Egr-1 directly binds the psoriasin promoter. Our findings present a novel signalling mechanism by which IL-17A can induce the Egr-1-dependent psoriasin expression via the ERK pathway in human keratinocytes. This study suggests that Egr-1 may be a novel and important modulator in IL-17A-mediated immune response in psoriasis.

Comparison of the effects of normal saline versus Plasmalyte on acid-base balance during living donor kidney transplantation using the Stewart and base excess methods

BACKGROUND

Ischemia-reperfusion injury is an inevitable consequence of kidney transplantation, leading to metabolic acidosis. This study compared the effects of normal saline (NS) and Plasmalyte on acid-base balance and electrolytes during living donor kidney transplantation using the Stewart and base excess (BE) methods.

METHODS

Patients were randomized to an NS group (n = 30) or a Plasmalyte group (n = 30). Arterial blood samples were collected for acid-base analysis after induction of anesthesia (T0), prior to clamping the iliac vein (T1), 10 minutes after reperfusion of the donated kidney (T2), and at the end of surgery (T3). In addition serum creatinine and 24-hour urine output were recorded on postoperative days 1,2, and 7. Over the first postoperative 7 days we recorded episodes of graft failure requiring dialysis.

RESULTS

Compared with the Plasmalyte group, the NS group showed significantly lower values of pH, BE, and effective strong ion differences during the postreperfusion period (T2 and T3). Chloride-related values (chloride [Cl(-)], free-water corrected Cl(-), BEcl) were significantly higher at T1, T2, and T3, indicating hyperchloremic rather than dilutional metabolic acidosis. Early postoperative graft functions in terms of serum creatinine, urine output, and graft failure requiring dialysis were not significantly different between the groups.

CONCLUSIONS

Both NS and Plamalyte can be used safely during uncomplicated living donor kidney transplantation. However, Plasmalyte more stably maintains acid-base and electrolyte balance compared with NS especially during the postreperfusion period.

Development progresses of radio frequency ion source for neutral beam injector in fusion devices

A large-area RF (radio frequency)-driven ion source is being developed in Germany for the heating and current drive of an ITER device. Negative hydrogen ion sources are the major components of neutral beam injection systems in future large-scale fusion experiments such as ITER and DEMO. RF ion sources for the production of positive hydrogen (deuterium) ions have been successfully developed for the neutral beam heating systems at IPP (Max-Planck-Institute for Plasma Physics) in Germany. The first long-pulse ion source has been developed successfully with a magnetic bucket plasma generator including a filament heating structure for the first NBI system of the KSTAR tokamak. There is a development plan for an RF ion source at KAERI to extract the positive ions, which can be applied for the KSTAR NBI system and to extract the negative ions for future fusion devices such as the Fusion Neutron Source and Korea-DEMO. The characteristics of RF-driven plasmas and the uniformity of the plasma parameters in the test-RF ion source were investigated initially using an electrostatic probe.

Improvement of a plasma uniformity of the 2nd ion source of KSTAR neutral beam injector

The 2nd ion source of KSTAR (Korea Superconducting Tokamak Advanced Research) NBI (Neutral Beam Injector) had been developed and operated since last year. A calorimetric analysis revealed that the heat load of the back plate of the ion source is relatively higher than that of the 1st ion source of KSTAR NBI. The spatial plasma uniformity of the ion source is not good. Therefore, we intended to identify factors affecting the uniformity of a plasma density and improve it. We estimated the effects of a direction of filament current and a magnetic field configuration of the plasma generator on the plasma uniformity. We also verified that the operation conditions of an ion source could change a uniformity of the plasma density of an ion source.

Mitochondrial modulation decreases the bortezomib-resistance in multiple myeloma cells

Multiple myeloma (MM) is an incurable hematological malignancy that causes most patients to eventually relapse and die from their disease. The 20S proteasome inhibitor bortezomib has emerged as an effective drug for MM treatment; however, intrinsic and acquired resistance to bortezomib has already been observed in MM patients. We evaluated the involvement of mitochondria in resistance to bortezomib-induced cell death in two different MM cell lines (bortezomib-resistant KMS20 cells and bortezomib-sensitive KMS28BM cells). Indices of mitochondrial function, including membrane potential, oxygen consumption rate and adenosine-5'-triphosphate and mitochondrial Ca(2+) concentrations, were positively correlated with drug resistance of KMS cell lines. Mitochondrial genes including CYPD, SOD2 and MCU were differentially expressed in KMS cells. Thus, changes in the expression of these genes lead to changes in mitochondrial activity and in bortezomib susceptibility or resistance, and their combined effect contributes to differential sensitivity or resistance of MM cells to bortezomib. In support of this finding, coadministration of bortezomib and 2-methoxyestradiol, a SOD inhibitor, rendered KMS20 cells sensitive to apoptosis. Our results provide new insight into therapeutic modalities for MM patients. Studying mitochondrial activity and specific mitochondrial gene expression in fresh MM specimens might help predict resistance to proapoptotic chemotherapies and inform clinical decision-making.