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1.
Appl Microsc ; 51(1): 19, 2021 Dec 23.
Article in English | MEDLINE | ID: mdl-34940919

ABSTRACT

The main purpose of this paper is the preparation of transmission electron microscopy (TEM) samples from the microsized powders of lithium-ion secondary batteries. To avoid artefacts during TEM sample preparation, the use of ion slicer milling for thinning and maintaining the intrinsic structure is described. Argon-ion milling techniques have been widely examined to make optimal specimens, thereby making TEM analysis more reliable. In the past few years, the correction of spherical aberration (Cs) in scanning transmission electron microscopy (STEM) has been developing rapidly, which results in direct observation at an atomic level resolution not only at a high acceleration voltage but also at a deaccelerated voltage. In particular, low-kV application has markedly increased, which requires a sufficiently transparent specimen without structural distortion during the sample preparation process. In this study, sample preparation for high-resolution STEM observation is accomplished, and investigations on the crystal integrity are carried out by Cs-corrected STEM.

2.
J Cerebrovasc Endovasc Neurosurg ; 22(3): 182-189, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32971577

ABSTRACT

We present the case of a patient who developed compressive radiculopathy that was found to be associated with a spinal extradural arteriovenous fistula. The fistula was successfully obliterated with transarteiral balloon-assisted coiling, after which the patient was symptom-free. Although spinal extradural arteriovenous fistula is rare, this pathology should be considered in the differential diagnosis of spinal radiculopathy or myelopathy. Endovascular treatment appears to have been successful in resolving the symptoms associated with this pathology.

3.
J Cerebrovasc Endovasc Neurosurg ; 22(2): 65-77, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32665913

ABSTRACT

OBJECTIVE: The aim of this study was to assess the feasibility, safety and efficiency of minipterional craniotomy (MPT) for surgical clipping of anterior circulation aneurysms. METHODS: A retrospective study was conducted to compare the MPT from Jan 2015 to Dec 2018 and conventional pterional craniotomy (CPT) from Jan 2012 to Dec 2013 in unruptured intracranial aneurysms (UIA) and ruptured intracranial aneurysms (RIA). The feasibility and safety of MPT and CPT were assessed by analyzing medical records, radiologic imaging, and clinical outcomes. The efficiency of MPT and CPT were based on a survey research of temporomandibular dysfunction, facial nerve paralysis, and facial asymmetry. RESULTS: Total 628 patients who underwent 458 MPT (UIA:313, RIA:145) and 170 CPT (UIA: 106, RIA: 64) with anterior circulation aneurysms were included in this study. The baseline characteristics between MPT and CPT had no difference (p>0.05). There was no difference in the incidence of postoperative hemorrhage or ischemic lesions between MPT and CPT (p>0.05). The incidence of surgical wound infection was lower in MPT (0.4%) than CPT (3.5%) (p=0.002). More than 90% of postoperative pain disappeared faster in MPT (14.25±4.83 days) than CPT (27.59±10.35 days), and the feeling of facial asymmetry in surgical side was also lower for MPT (1.7%) than CPT (7.6%) (p<0.001). In the MPT, no patients presented with progress to chronic pain, masticatory disability, discomfort of maximal mouth opening or permanent facial palsy. CONCLUSIONS: We suggest that MPT and CPT had similar clinical outcomes, and MPT showed better functional and cosmetic outcomes than CPT in terms of temporomandibular dysfunction, facial nerve paralysis, and facial asymmetry. Therefore, MPT for surgical clipping of anterior circulation aneurysms can be a compatible technique that satisfies the feasibility, safety and efficiency.

4.
Nutrients ; 12(3)2020 Mar 02.
Article in English | MEDLINE | ID: mdl-32131519

ABSTRACT

Chronic exposure to cisplatin is associated with irreversible kidney impairment. In this present study, we explored the protective effects of 3-dehydroxyceanothetric acid 2-methyl ester (3DC2ME) isolated from roots of jujube (Ziziphus jujuba, Rhamnaceae) against cisplatin-induced damage in vitro. In kidney epithelial LLC-PK1 cells, western blotting and staining with specific autophagy epifluorescent dye CytoID were used to determine the molecular pathways involving autophagy. Treatment with 3DC2ME reduced the increased Cyto-ID-stained autophagic vesicles and reversed the protein expressions of 5' AMP-activated protein kinase subunit ß-1 (AMPK)/mammalian target of rapamycin (mTOR)-dependent signaling pathway in cisplatin-induced cell death. Additionally, treatment with autophagy inhibitor 3-methyladenine (3-MA) and with or without 3DC2ME attenuated the cisplatin-induced apoptosis. Although further research is necessary to substantiate the effects, we evaluated the potential mechanism of action of 3DC2ME as an adjuvant for cancer patients.


Subject(s)
Acute Kidney Injury/prevention & control , Autophagy/drug effects , Cisplatin/adverse effects , Epithelial Cells/metabolism , Kidney/metabolism , Plant Roots/chemistry , Triterpenes/pharmacology , Ziziphus/chemistry , Acute Kidney Injury/chemically induced , Acute Kidney Injury/metabolism , Acute Kidney Injury/pathology , Animals , Cell Line , Cisplatin/pharmacology , Epithelial Cells/pathology , Kidney/pathology , Swine , Triterpenes/chemistry
5.
Biomolecules ; 10(3)2020 03 09.
Article in English | MEDLINE | ID: mdl-32182890

ABSTRACT

Immune response is a necessary self-defense mechanism that protects the host from infectious organisms. Many medicinal plants are popularly used in Asian folk medicine to increase body resistance. An herbal formulation named KM1608 was prepared from three medicinal plants: Saussurea lappa, Terminalia chebula, and Zingiber officinale. In this study, we evaluated the immune stimulatory effect of KM1608 on RAW 264.7 murine macrophages. Network pharmacological analyses were used to predict potential immune response pathways of major compounds from KM1608. The cytotoxicity and immuno-stimulating effect of KM1608 were determined using cell viability and nitric oxide assays. The underlying mechanism of immunomodulatory activity was evaluated by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) of pro-inflammatory cytokines. The results of network pharmacological analysis suggested that major compounds from KM1608 possess anticancer potential via immune signaling pathways. After treatment with KM1608 at 25-100 µg/mL for 24 h, the level of nitric oxide was increased in the dose-dependent manner. The results of quantitative real-time PCR showed that KM1608 stimulates the expression of immune cytokines (interferon (IFN)-α, -ß, IL-1ß, -6, IL-10, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2)) in macrophages. KM1608 extract is a potential agent for immune response enhancement.


Subject(s)
Adjuvants, Immunologic/pharmacology , Gene Expression Regulation , Macrophages/immunology , Plant Extracts/pharmacology , Plants, Medicinal/chemistry , Signal Transduction , Adjuvants, Immunologic/chemistry , Animals , Gene Expression Regulation/drug effects , Gene Expression Regulation/immunology , Mice , Monokines/immunology , Nitric Oxide Synthase Type II/immunology , Plant Extracts/chemistry , RAW 264.7 Cells , Signal Transduction/drug effects , Signal Transduction/immunology
6.
Bioorg Chem ; 90: 103053, 2019 09.
Article in English | MEDLINE | ID: mdl-31220671

ABSTRACT

We evaluated the protective effects of hypoxylonol C and 4,5,4',5'-tetrahydroxy-1,1'-binaphthyl (BNT) isolated from Annulohypoxylon annulatum on pancreatic ß-cell apoptosis, using the ß-cell toxin streptozotocin (STZ). Hypoxylonol C and BNT restored the STZ-induced decrease in INS-1 cell viability in a dose-dependent manner. In addition, treatment of INS-1 cells with 50 µM STZ resulted in an increase in apoptotic cell death, which was observed as annexin V fluorescence intensity. Apoptotic cell death was decreased by co-treatment with 100 µM hypoxylonol C and 100 µM BNT. Similarly, STZ caused a marked increase in the expression of cleaved caspase-8, caspase-3, Bax, and poly (ADP-ribose) polymerase (PARP), as well as a decrease in the expression of B-cell lymphoma 2 (Bcl-2), which was reversed by co-treatment with 100 µM hypoxylonol C and 100 µM BNT. These findings suggest that hypoxylonol C and BNT play an important role in protecting pancreatic ß-cells against apoptotic damage.


Subject(s)
Fluorenes/pharmacology , Naphthols/pharmacology , Protective Agents/pharmacology , Streptozocin/toxicity , Animals , Apoptosis/drug effects , Ascomycota/chemistry , Caspase 3/metabolism , Caspase 8/metabolism , Cell Line, Tumor , Fluorenes/isolation & purification , Insulin-Secreting Cells/drug effects , Naphthols/isolation & purification , Oxidative Stress/drug effects , Poly(ADP-ribose) Polymerases/metabolism , Protective Agents/isolation & purification , Proto-Oncogene Proteins c-bcl-2/metabolism , Rats , Reactive Oxygen Species/metabolism , bcl-2-Associated X Protein/metabolism
7.
J Clin Pharmacol ; 58(7): 905-912, 2018 07.
Article in English | MEDLINE | ID: mdl-29537612

ABSTRACT

Udenafil is a phosphodiesterase-5 inhibitor used to treat erectile dysfunction. Although udenafil is not predominantly eliminated by the kidney, renal impairment can alter its secretion/transport pathways. Drug pharmacokinetics and safety must therefore be assessed in subjects with a renal impairment. We investigated the effects of impaired renal function on the pharmacokinetics and safety of a single 100-mg oral dose of udenafil in a single-dose, open-label, parallel-group study of 31 subjects. Cockcroft-Gault creatinine clearance was used to stratify these subjects into healthy controls (>80 mL·min-1 ) and individuals with mild (50 to ≤80 mL·min-1 ), moderate (30 to ≤50 mL·min-1 ), and severe (<30 mL·min-1 ) renal impairment. Pharmacokinetic measurements and safety assessments indicated that the geometric mean of the area under the concentration-time curve to the last measurement in mildly, moderately, and severely renally impaired subjects was 1.30- (90% CI 1.05-1.60), 1.62- (90% CI 1.28-2.06), and 1.60- (90% CI 1.28-2.01) fold higher, respectively, than the healthy controls. The geometric mean of the maximum observed concentration was 1.41- (90% CI 1.05-1.88), 2.02- (90% CI 1.47-2.79), and 1.65- (90% CI: 1.21-2.24) fold higher, respectively. Significant correlations were observed among the creatinine clearance, oral clearance, and maximum concentration of udenafil (P < .01). All adverse events were mild, and no subject discontinued the study. Udenafil administration was well tolerated in all groups. In view of the clinical relevance of drug exposure, our findings indicate that a dose adjustment of udenafil is warranted in subjects with moderate or severe renal impairment.


Subject(s)
Phosphodiesterase 5 Inhibitors/pharmacokinetics , Pyrimidines/pharmacokinetics , Renal Insufficiency/metabolism , Sulfonamides/pharmacokinetics , Administration, Oral , Adult , Aged , Area Under Curve , Female , Humans , Male , Middle Aged , Young Adult
8.
ACS Appl Mater Interfaces ; 9(1): 304-310, 2017 01 11.
Article in English | MEDLINE | ID: mdl-27997112

ABSTRACT

The successful analysis on the microstructure of Hong-type Na superionic conducting (NASICON) ceramics revealed that it consists of several heterogeneous phases: NASICON grains with rectangular shapes, monoclinic round ZrO2 particles, grain boundaries, a SiO2-rich vitrified phase, Na-rich amorphous particles, and pores. A dramatic microstructural evolution of NASICON ceramics was demonstrated via an in situ analysis, which showed that NASICON grains sequentially lost their original morphology and were transformed into comminuted particles (as indicated by the immersion of bulk NASICON samples into seawater at a temperature of 80 °C). The consecutive X-ray diffraction analysis represented that the significant shear stress inside NASICON ceramics caused their structural decomposition, during which H3O+ ions occupied ceramic Na+ sites (predominantly along the (1̅11) and (1̅33) planes), while the original Na+ cations came out in the (020) plane of the NASICON ceramic crystalline structure. The results of time-of-flight secondary-ion mass spectrometry analysis confirmed that large concentrations of Cl- and Na+ ions were distributed across the surface of NASICON ceramics, leading to local densification of a 20 µm thick surface layer after treatment within seawater solution at a temperature of 80 °C.

9.
Clin Transplant ; 29(2): 142-8, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25560652

ABSTRACT

We investigated the effects of pregnancy and delivery on renal function in transplant recipients and the relationship between doses of immunosuppressants and blood drug levels during pregnancy in 75 women with 88 deliveries. Significant serum creatinine elevation (> 0.5 mg/dL) was found in eight deliveries. In the remaining 80 cases, serum creatinine was reduced by an average of 0.14 mg/dL and returned to pre-pregnant levels after delivery. Tacrolimus was used in 28 deliveries and cyclosporine in others. Tacrolimus blood trough level declined from 5.8 ± 2.8 ng/mL 12 months before delivery to 4.2 ± 1.8 ng/mL at second trimester; therefore, drug dose was increased from 4.1 ± 1.9 mg/d at first trimester to 5.5 ± 2.5 mg/d at delivery. Similarly, cyclosporine levels were 125.1 ± 65.1 ng/mL 12 months before delivery and 75.4 ± 35.0 ng/mL at second trimester resulting in dose elevation from 183.0 ± 71.8 mg/d at first trimester to 225.4 ± 85.1 mg/d at delivery. Renal function in female kidney transplant recipients improved slightly during pregnancy and returned to pre-pregnant level after delivery. The dose elevation of calcineurin inhibitor by approximately 20-25% should be considered during gestational period to maintain optimal blood drug level.


Subject(s)
Calcineurin Inhibitors/therapeutic use , Graft Rejection/drug therapy , Kidney Transplantation , Pregnancy Complications , Adult , Female , Follow-Up Studies , Humans , Infant, Newborn , Male , Pregnancy , Pregnancy Outcome , Retrospective Studies
10.
J Antimicrob Chemother ; 70(5): 1567-72, 2015 May.
Article in English | MEDLINE | ID: mdl-25608587

ABSTRACT

BACKGROUND: We performed a randomized trial of isoniazid treatment based on interferon-γ-releasing assay (IGRA) in kidney transplant (KT) recipients in an intermediate-TB-burden country. METHODS: All adult patients admitted to a KT institute between June 2010 and May 2013 were enrolled. The IGRA (T-SPOT.TB assay) was performed on all patients, and isoniazid treatment was given to those with clinical risk factors for latent TB infection (LTBI). Patients with positive IGRA who had no clinical risk factors for LTBI were randomly assigned to isoniazid treatment or a control group. The development of TB after KT was monitored between June 2010 and November 2013. The primary endpoint was the development of TB. RESULTS: Of the 784 patients who had no clinical risk factors for LTBI, 445 (57%) gave negative results in the IGRA, 76 (10%) indeterminate results and 263 (33%) positive results. Of the latter, 131 were allocated to isoniazid treatment and 132 to the control group. Three (2%) of the control group developed TB, whereas none of the isoniazid treatment group developed TB (rate difference 1.22 per 100 person-years, P = 0.09). Of the 521 patients with negative or indeterminate IGRA results, 4 [0.8%, 0.43 per 100 person-years (95% CI 0.12-1.09)] developed TB after KT. CONCLUSIONS: IGRA-based isoniazid treatment has a trend towards reducing TB development in KT recipients without clinical risk factors, but careful monitoring of TB development is needed in negative-IGRA KT recipients.


Subject(s)
Antitubercular Agents/administration & dosage , Isoniazid/administration & dosage , Transplant Recipients , Tuberculosis/prevention & control , Adult , Female , Humans , Immunocompromised Host , Incidence , Interferon-gamma Release Tests , Kidney Transplantation , Male , Middle Aged , Pancreas Transplantation , Treatment Outcome
11.
Microscopy (Oxf) ; 63(1): 15-22, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24108788

ABSTRACT

Growing a GaN film on a patterned Al2O3 substrate is one of the methods of reducing threading dislocations (TDs), which can significantly deteriorate the performance of GaN-based LEDs. In this study, the microstructural details of the GaN film grown on a cone-shaped patterned Al2O3 substrate were investigated using high-resolution transmission electron microscopy and weak-beam dark-field techniques. Various defects such as misfit dislocations (MDs), recrystallized GaN (R-GaN) islands and nano-voids were observed on the patterned Al2O3 surfaces, i.e. the flat surface (FS), the inclined surface (IS) and the top surface (TS), respectively. Especially, the crystallographic orientation of R-GaN between the GaN film and the inclined Al2O3 substrate was identified as $[\overline 1 2\overline 1 0]_{{\rm GaN}} \hbox{//}[\overline 1 101]_{{\rm R - GaN} \,{\rm on}\,{\rm IS}} \hbox{//}[\overline 1 100]_{ {{\rm Al}} _{\rm 2} {\rm O}_{\rm 3}} $, $(\overline 1 012)_{{\rm GaN}} \hbox{//}(1\overline 1 02)_{{\rm R - Ga}\,{\rm Non}\,{\rm IS}} \hbox{//}(\overline {11} 26)_{ {{\rm Al}} _{\rm 2} {\rm O}_{\rm 3}} $. In addition, a rotation by 9° between $(10\overline 1 1)_{{\rm R - GaN}} $ and $(0002)_{{\rm GaN}} $ and between $(10\overline 1 1)_{{\rm R - GaN}} $ and $(0006)_{ {{\rm Al}} _{\rm 2} {\rm O}_{\rm 3}} $ was found to reduce the lattice mismatch between the GaN film and the Al2O3 substrate. Many TDs in the GaN film were observed on the FS and TS of Al2O3. However, few TDs were observed on the IS. Most of the TDs generated from the FS of Al2O3 were bent to the inclined facet rather than propagating to the GaN surface, resulting in a reduction in the dislocation density. Most of the TDs generated from the TS of Al2O3 were characterized as edge dislocations.

12.
Kidney Blood Press Res ; 37(4-5): 443-50, 2013.
Article in English | MEDLINE | ID: mdl-24247487

ABSTRACT

BACKGROUND: We compared the accuracy of the Modification of Diet in Renal Disease (MDRD) study and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations in Korean patients and evaluated the difference in CKD prevalence determined using the two equations in the Korean general population. METHODS: The accuracy of the two equations was evaluated in 607 patients who underwent a chromium-51-ethylenediaminetetraacetic acid GFR measurement. Additionally, we compared the difference in CKD prevalence determined by the two equations among 5,822 participants in the fifth Korea National Health and Nutrition Examination Survey, 2010. RESULTS: Among the 607 subjects, the median bias of the CKD-EPI equation was significantly lower than that of the MDRD study equation (0.9 vs. 2.2, p=0.020). The accuracy of the two equations was not significantly different in patients with mGFR <60 mL/min/1.73m(2); however, the accuracy of the CKD-EPI equation was significantly higher than that of the MDRD study equation in patients with GFR ≥60 mL/min/1.73m(2). The prevalences of the CKD stages 1, 2 and 3 in the Korean general population were 47.56, 49.23, and 3.07%, respectively, for the MDRD study equation; and were 68.48, 28.89, and 2.49%, respectively, for the CKD-EPI equation. CONCLUSIONS: These data suggest that the CKD-EPI equation might be more useful in clinical practice than the MDRD study equation in Koreans.


Subject(s)
Asian People/ethnology , Glomerular Filtration Rate/physiology , Nutrition Surveys/methods , Population Surveillance/methods , Renal Insufficiency, Chronic/diagnosis , Renal Insufficiency, Chronic/ethnology , Adult , Aged , Feeding Behavior/physiology , Female , Humans , Male , Middle Aged , Renal Insufficiency, Chronic/physiopathology , Republic of Korea/ethnology
13.
J Infect Chemother ; 19(5): 1009-13, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23917533

ABSTRACT

There are few data on donor screening for latent tuberculosis infection (LTBI) using the tuberculin skin test (TST) and interferon-gamma releasing assay (IGRA). In South Korea, most renal allografts involve living donors (average, 80%). Hence, we have an opportunity to evaluate donor and recipient screening for LTBI by TST and IGRA. All donors and recipients admitted for kidney transplantation during a 20-month period were evaluated prospectively by using TST and Mycobacterium tuberculosis-specific enzyme-linked immunosorbent spot (ELISPOT) assay. The study population consisted of 205 living donor-recipient pairs (≥16 years) including 15 (7%) who yielded indeterminate donor or recipient ELISPOT results. Of the 205 donors, 63 (31%) gave a positive TST ≥5 mm, 33 (16%) a positive TST ≥10 mm, and 96 (47%) a positive ELISPOT. Of the 205 recipients, 9 (5%) gave a positive TST ≥5 mm, 3 (2%) a positive TST ≥10 mm, and 79 (39%) had a positive ELISPOT. Of the 205 donor-recipient pairs, only 59 (29%) gave negative donor and recipient ELISPOT results and 139 (68%) negative donor and recipient TSTs (<5 mm) (P < 0.001). One third of donor-recipient pairs tends to be positive in the TST, and two thirds of the donor-recipient pairs tends to be positive in the ELISPOT. Given the high positive rate of LTBI obtained by screening donors, further studies on the clinical value of solid organ transplant donors with positive TST or ELISPOT and health economics analysis in countries with intermediate burden of TB are needed for policy decisions on isoniazid (INH) prophylaxis.


Subject(s)
Enzyme-Linked Immunospot Assay/methods , Interferon-gamma Release Tests/methods , Kidney Transplantation/methods , Latent Tuberculosis/diagnosis , Living Donors , Tuberculin Test/methods , Adult , Female , Humans , Male , Mass Screening , Middle Aged , Republic of Korea
14.
Am J Physiol Renal Physiol ; 304(6): F686-97, 2013 Mar 15.
Article in English | MEDLINE | ID: mdl-23324179

ABSTRACT

The epithelial-mesenchymal transition (EMT) is a novel mechanism that promotes renal fibrosis. Transforming growth factor-ß (TGF-ß), angiotensin II, aldosterone, high glucose, and urinary albumin are well-known causes of EMT and renal fibrosis. We examined whether and how activation of AMP-activated protein kinase (AMPK) suppressed EMT induced by the above agents in tubular epithelial cells. All experiments were performed using HK-2 cells. Protein expression was measured by Western blot analysis. Intracellular reactive oxygen species (ROS) were analyzed by flow cytometry. Exposure of tubular cells to TGF-ß (10 ng/ml), angiotensin II (1 µM), aldosterone (100 nM), high glucose (30 mM), and albumin (5 mg/ml) for 5 days induced EMT, as shown by upregulation of α-smooth muscle actin and downregulation of E-cadherin. ROS and NADPH oxidase 4 (Nox4) expression were increased, and antioxidants such as tiron and N-acetylcysteine inhibited EMT induction. Metformin (the best known clinical activator of AMPK) suppressed EMT induction through inhibition of ROS via induction of heme oxygenase-1 and endogenous antioxidant thioredoxin. An AMPK inhibitor (compound C) and AMPK small interfering RNA blocked the effect of metformin, and another AMPK activator [5-aminoimidazole-4-carboxamide-1ß riboside (AICAR)] exerted the same effects as metformin. In conclusion, AMPK activation might be beneficial in attenuating the tubulointerstitial fibrosis induced by TGF-ß, angiotensin II, aldosterone, high glucose, and urinary albumin.


Subject(s)
AMP-Activated Protein Kinases/metabolism , Epithelial-Mesenchymal Transition , Heme Oxygenase-1/metabolism , Nephrosclerosis/enzymology , Thioredoxins/metabolism , Albumins/metabolism , Aldosterone/metabolism , Aminoimidazole Carboxamide/analogs & derivatives , Angiotensin II/metabolism , Cell Line , Glucose/metabolism , Humans , Metformin , NADPH Oxidase 4 , NADPH Oxidases/metabolism , Pyrazoles , Pyrimidines , Reactive Oxygen Species/metabolism , Ribonucleosides , Transforming Growth Factor beta/metabolism
15.
Cell Biol Int ; 37(1): 19-28, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23319318

ABSTRACT

Atherosclerosis develops from cascades of inflammatory processes. Spleen tyrosine kinase (Syk) and monocyte chemotatic protein-1 (MCP-1) play important roles in the pathogenesis of atherosclerosis. Mycophenolic acid (MPA) has an anti-inflammatory effect. We have investigated whether MPA regulates Syk to repress tumour necrosis factor-α (TNF-α)-induced MCP-1 production in cultured human aortic endothelial cells. Expression of MCP-1 mRNA and its protein were measured by real time RT-PCR and ELISA, respectively. Reactive oxygen species (ROS) production were measured using 2'7'-dichlorofluorescein diacetate. Activation of AP-1 and NF-κB were assessed by electrophoretic mobility shift assay. Tyrosine phosphorylation of Syk was examined by Western blot analysis. TNF-α increased MCP-1 at both mRNA and protein levels. TNF-α-induced MCP-1 mRNA expression was inhibited by N-acetylcysteine (NAC), Syk inhibitor, Syk-siRNA and MPA. TNF-α-induced MCP-1 protein production was also inhibited by Syk inhibitor and MPA. TNF-α increased DNA binding activity of AP-1 and NF-κB, whereas both AP-1 and NF-κB decoy oligodeoxynucleotides downregulated TNF-α-induced MCP-1 mRNA expression. TNF-α increased ROS generation, which was inhibited by NAC and MPA, but not by Syk inhibitor. TNF-α increased tyrosine phosphorylation of Syk, which was attenuated by NAC and MPA. MPA and Syk inhibitor attenuated TNF-α-induced DNA binding activity of NF-κB and AP-1. TNF-α induced MCP-1 expression via activation of AP-1 and NF-κB. AP-1 and NF-κB were mediated through ROS, followed by Syk. MPA exerts anti-inflammatory effect by inhibiting MCP-1 expression via suppression of ROS and Syk.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Chemokine CCL2/biosynthesis , Endothelial Cells/drug effects , Intracellular Signaling Peptides and Proteins/genetics , Mycophenolic Acid/pharmacology , Protein-Tyrosine Kinases/genetics , Tumor Necrosis Factor-alpha/genetics , Aorta/cytology , Aorta/metabolism , Endothelial Cells/cytology , Endothelial Cells/metabolism , Endothelium, Vascular/cytology , Endothelium, Vascular/metabolism , Humans , Intracellular Signaling Peptides and Proteins/metabolism , NF-kappa B/metabolism , Protein-Tyrosine Kinases/metabolism , Reactive Oxygen Species/metabolism , Signal Transduction , Syk Kinase , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Tumor Necrosis Factor-alpha/metabolism
17.
Nephron Exp Nephrol ; 121(1-2): e38-48, 2012.
Article in English | MEDLINE | ID: mdl-23108012

ABSTRACT

BACKGROUND: Endoplasmic reticulum (ER) stress induced by urinary albumin plays an important role in tubulointerstitial injury. We have shown that albumin-induced ER stress is regulated through reactive oxygen species (ROS)-c-Src kinase-mTOR signaling pathways. We postulated that peroxisome proliferator-activated receptor-γ (PPAR-γ) might also act as an upstream signaling molecule between c-Src kinase and mTOR. It has been suggested that AMP-activated protein kinase (AMPK) is involved in attenuation of ER stress. We examined whether and how activation of AMPK suppressed the albumin-induced ER stress and apoptosis in tubular epithelial cells. METHOD: HK-2 cells, a proximal tubular cell line, were used. Protein expressions were measured by Western blot analysis. Intracellular ROS and apoptosis were analyzed by flow cytometry. RESULTS: Albumin-induced PPAR-γ expression and PPAR-γ inhibitor (GW9662) suppressed the albumin-induced ER stress. c-Src kinase inhibitor and GW9662 reduced the albumin-induced PPAR-γ and mTOR, respectively. Metformin (the best known clinical activator of AMPK) and another AMPK activator (AICAR) suppressed the albumin-induced ER stress via inhibition of ROS through induction of endogenous antioxidant thioredoxin. AMPK inhibitor blocked the effect of metformin and AICAR. Our in vivo animal study showed that metformin reduced the renal cortical expression of ER stress protein (GRP78) in protein-overload proteinuria rats. Metformin also reduced the caspase 3-dependent apoptosis induced by albumin. CONCLUSION: PPAR-γ was involved in albumin-induced ER stress as an upstream signaling molecule between c-Src kinase and mTOR. AMPK activation might be beneficial in attenuating the tubulointerstitial injury induced by albumin.


Subject(s)
AMP-Activated Protein Kinases/metabolism , Apoptosis/physiology , Endoplasmic Reticulum/physiology , Kidney Tubules/physiology , Reactive Oxygen Species/metabolism , Serum Albumin/pharmacology , Stress, Physiological/physiology , Animals , Apoptosis/drug effects , Cell Line , Endoplasmic Reticulum/drug effects , Endoplasmic Reticulum Chaperone BiP , Enzyme Activation/drug effects , Humans , Kidney Tubules/cytology , Kidney Tubules/drug effects , Male , Rats , Rats, Wistar , Reactive Oxygen Species/antagonists & inhibitors , Stress, Physiological/drug effects
18.
Int J Clin Pharmacol Ther ; 50(12): 880-8, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23006442

ABSTRACT

OBJECTIVE: To evaluate and compare the pharmacokinetics and tolerability of a single oral dose of mirodenafil in volunteer patients with severe renal impairment and healthy volunteers. METHODS AND MATERIALS: This open-label, single-dose, parallel group clinical study enrolled a total 12 volunteers (6 healthy volunteers and 6 volunteer patients with severe renal impairment). Each volunteer was orally administered 50 mg mirodenafil and serial blood samples were obtained after drug administration to determine the plasma concentration of mirodenafil using LC-MS/MS. The measured individual plasma concentrations were used to calculate the pharmacokinetic parameters using noncompartmental methods. Tolerability was also assessed using measurements of vital signs, clinical chemistry tests, and interviews. RESULTS: All of the volunteers completed the study with no serious adverse events (AEs). A total of 4 AEs were reported, but all were of mild or moderate intensity and not considered to be related to the study drug. The geometric mean (95% CI) of the terminal half-life (t1/2ß) and the apparent clearance (CL/F) values of mirodenafil were 2.2 (1.4 - 3.4) h and 127.2 (95.1 - 170.2) l/h in the volunteer patients, and 3.0 (2.1 - 4.4) h and 136.1 (74.4 - 249.2) l/h in the healthy volunteers, respectively. The geometric mean of the AUC0-t of the volunteer patients was 8% higher and the geometric mean for clearance was 7% lower compared with the healthy volunteers. However, the geometric mean of the Cmax of the volunteer patients was 38% higher than that of the healthy volunteers. CONCLUSIONS: A single oral 50-mg dose of mirodenafil was well tolerated. Exposure (AUC0-t) to mirodenafil was similar in both healthy volunteers and volunteer patients with severe renal impairment and healthy volunteers.


Subject(s)
Phosphodiesterase 5 Inhibitors/pharmacokinetics , Pyrimidinones/pharmacokinetics , Renal Insufficiency/metabolism , Sulfonamides/pharmacokinetics , Adult , Chromatography, Liquid , Humans , Male , Middle Aged , Pyrimidinones/adverse effects , Sulfonamides/adverse effects , Tandem Mass Spectrometry
19.
Shock ; 38(1): 30-6, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22706021

ABSTRACT

We hypothesized that the time from sepsis to inception of continuous renal replacement therapy (CRRT) can be used to predict survival rates in patients with septic acute kidney injury (AKI). The survival predictability of CRRT inception time was compared with that of RIFLE criteria, which were previously used in clinical practice. We retrospectively analyzed outcomes in 55 patients with septic AKI admitted to the medical intensive care unit at Asan Medical Center (Seoul, Korea) between April 2009 and October 2010. These patients were stratified by the time of inception of CRRT from sepsis (early: ≤ 24 h and late: >24 h) and also by the RIFLE criteria (RIFLE-I and RIFLE-F). The primary outcome was 28-day mortality. Of the 55 patients, 38 (69.1%) were male. Patients' mean age was 62.6 years, the most common infection site was the lung (32, 58.2%), and 47 patients (85.5%) were on mechanical ventilation. Thirty patients (54.5%) were in the RIFLE-I, and the others were in the RIFLE-F. Twenty-eight-day mortality rates were lower in the early group than in the late group (19.4% vs. 47.4%; P = 0.03), but did not differ between RIFLE-I and RIFLE-F. Ventilator-free day at day 28 was longer in the early group than that in the late group (7.5 vs. 0 d; P = 0.033). After adjustment for covariates, we found that the late group (hazard ratio, 3.106; 95% confidence interval, 1.066-9.047) and Sequential Organ Failure Assessment at sepsis (hazard ratio, 1.410; 95% confidence interval, 1.108-1.796) were independent factors associated with 28-day mortality. This study suggests that the time interval from sepsis to CRRT inception may be a more useful predictor of 28-day mortality than RIFLE criteria in patients with septic AKI.


Subject(s)
Acute Kidney Injury/etiology , Acute Kidney Injury/therapy , Renal Replacement Therapy , Sepsis/complications , Acute Kidney Injury/diagnosis , Aged , Female , Humans , Intensive Care Units , Kaplan-Meier Estimate , Length of Stay/statistics & numerical data , Male , Middle Aged , Prognosis , Retrospective Studies , Severity of Illness Index , Time Factors
20.
Clin Nephrol ; 78(5): 391-8, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22541689

ABSTRACT

BACKGROUND/AIMS: Hepatitis B virus (HBV) infection can adversely affect the clinical outcome of kidney transplantation (KT). Short-term efficacy of lamivudine has been demonstrated for chronic hepatitis B in KT recipients (KTR). METHODS: To clarify the long-term impact of antiviral treatment for HBV-positive KTR, we retrospectively reviewed 94 HBV-positive (male 73%) and 282 age/sex-matched HBV-negative patients who underwent KT from February 1997 to November 2009, after lamivudine had come into wide use. RESULTS: Mean follow-up was 75.7 months. 56 patients received antiviral agent for prophylaxis, and other 18 for HBV reactivation. During follow-up, 15 died, with 5 deaths being HBV related. Although the patient survival rate was lower for HBVpositive than HBV-negative KTRs (89% vs. 94% at 5 years, 78% vs. 88% at 10 years, p = 0.031), graft survival was comparable (86% vs. 92% at 5 years, 73% vs. 81% at 10 years, p = 0.113). In multivariate analysis, HBsAg positivity was a significant risk factor for patient death (OR 2.19, 95% CI 1.14 - 4.20, p = 0.019), but not significant for graft loss (OR 1.64, 95% CI 0.94 - 2.86, p = 0.079). Of the 26 hepatitis B e antigen (HBeAg)-positive patients, 14 experienced HBV reactivations, but all survived with stable liver chemistry, except for one who died of hepatocellular carcinoma. Among 57 HBeAg-negative patients, 12 died, whereas the remaining 45 survived without hepatic dysfunction. CONCLUSION: Long-term outcomes of HBV-positive KTRs may be favorable after antiviral agents have been introduced.


Subject(s)
Antiviral Agents/therapeutic use , Hepatitis B, Chronic/drug therapy , Kidney Transplantation , Adult , Female , Graft Survival , Hepatitis B e Antigens/analysis , Humans , Kidney Transplantation/mortality , Male , Middle Aged , Transplantation, Homologous , Treatment Outcome
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