140 research outputs found
One-step large-scale synthesis of micrometer-sized silver nanosheets by a template-free electrochemical method
Downregulation of Protein Kinase CK2 Activity Facilitates Tumor Necrosis Factor-α-Mediated Chondrocyte Death through Apoptosis and Autophagy
Despite the numerous studies of protein kinase CK2, little progress has been made in understanding its function in chondrocyte death. Our previous study first demonstrated that CK2 is involved in apoptosis of rat articular chondrocytes. Recent studies have suggested that CK2 downregulation is associated with aging. Thus examining the involvement of CK2 downregulation in chondrocyte death is an urgently required task. We undertook this study to examine whether CK2 downregulation modulates chondrocyte death. We first measured CK2 activity in articular chondrocytes of 6-, 21- and 30-month-old rats. Noticeably, CK2 activity was downregulated in chondrocytes with advancing age. To build an in vitro experimental system for simulating tumor necrosis factor (TNF)-α-induced cell death in aged chondrocytes with decreased CK2 activity, chondrocytes were co-treated with CK2 inhibitors and TNF-α. Viability assay demonstrated that CK2 inhibitors facilitated TNF-α-mediated chondrocyte death. Pulsed-field gel electrophoresis, nuclear staining, flow cytometry, TUNEL staining, confocal microscopy, western blot and transmission electron microscopy were conducted to assess cell death modes. The results of multiple assays showed that this cell death was mediated by apoptosis. Importantly, autophagy was also involved in this process, as supported by the appearance of a punctuate LC3 pattern and autophagic vacuoles. The inhibition of autophagy by silencing of autophage-related genes 5 and 7 as well as by 3-methyladenine treatment protected chondrocytes against cell death and caspase activation, indicating that autophagy led to the induction of apoptosis. Autophagic cells were observed in cartilage obtained from osteoarthritis (OA) model rats and human OA patients. Our findings indicate that CK2 down regulation facilitates TNF-α-mediated chondrocyte death through apoptosis and autophagy. It should be clarified in the future if autophagy observed is a consequence versus a cause of the degeneration in vivo
Response: Basal C-peptide Level as a Surrogate Marker of Subclinical Atherosclerosis in Type 2 Diabetic Patients (Diabetes Metab J 2011;35:41-9)
Initial Experience with Robotic-Assisted Laparoscopic Partial Cystectomy in Urachal Diseases
Purpose: In this study, we report our initial experience with robot-assisted laparoscopic partial cystectomy (RLPC) in urachal diseases. Materials and Methods: Two men and two women with a mean age of 51.5??9.3 years underwent RLPC between June 2009 and December 2009. In each case, a single surgeon using the da Vinci-S robotic system (Intuitive Surgical, Sunnyvale, CA, USA) used a transperitoneal approach with a 0?? robotic camera. After careful observation of the intravesical portion of the mass, the mass was excised by use of monopolar scissors circumferentially. The bladder was closed in two layers with watertight running sutures made with 2-0 Vicryl. Results: The mean operative time was 198 minutes (range, 130-260 minutes), the mean console time was 111 minutes (range, 70-150 minutes), and the mean estimated blood loss was 155 ml. The urethral catheter was removed on postoperative day 7 after a normal cystogram, and the surgical drain was removed on postoperative day 2.5 (range, 2-3 days). The mean hospital stay was 6 days (range, 4-7 days). There were no major complications. The pathology report revealed that one patient had a urachal cystadenoma, two patients had a urachal cyst, and one patient had a patent urachus. Conclusions: Our initial experience with RLPC for benign urachal disease is that it is a safe and feasible treatment modality. However, more cases are required to confirm the efficacy of RLPC. ?? The Korean Urological Association, 2010
Immunotherapy of Malignant Melanoma with Tumor Lysate-Pulsed Autologous Monocyte-Derived Dendritic Cells
PURPOSE: Dendritic cell (DC) vaccination for melanoma was introduced because melanoma carries distinct tumor-associated antigens. The purpose of this study was to investigate the efficacy and safety of DC vaccination for melanoma in Korea.
MATERIALS AND METHODS: Five patients with stage IV and one with stage II were enrolled. Autologous monocyte-derived DCs (MoDCs) were cultured and pulsed with tumor-lysate, keyhole limpet hemocyanin, and cytokine cocktail for mature antigen-loaded DC. DC vaccination was repeated four times at 2-week intervals and 2-4×10⁷ DC were injected each time.
RESULTS: Reduced tumor volume was observed by PET-CT in three patients after DC vaccination. Delayed type hypersensitivity responses against tumor antigen were induced in five patients. Tumor antigen-specific IFN-γ-producing peripheral blood mononuclear cells were detected with enzyme-linked immunosorbent spot in two patients. However, the overall clinical outcome showed disease progression in all patients.
CONCLUSION: In this study, DC vaccination using tumor antigen-loaded, mature MoDCs led to tumor regression in individual melanoma patients. Further standardization of DC vaccination protocol is required to determine which parameters lead to better anti-tumor responses and clinical outcomes.ope
Cellular uptake of magnetic nanoparticle is mediated through energy-dependent endocytosis in A549 cells
Biocompatible silica-overcoated magnetic nanoparticles containing an organic fluorescence dye, rhodamine B isothiocyanate (RITC), within a silica shell [50 nm size, MNP@SiO2(RITC)s] were synthesized. For future application of the MNP@SiO2(RITC)s into diverse areas of research such as drug or gene delivery, bioimaging, and biosensors, detailed information of the cellular uptake process of the nanoparticles is essential. Thus, this study was performed to elucidate the precise mechanism by which the lung cancer cells uptake the magnetic nanoparticles. Lung cells were chosen for this study because inhalation is the most likely route of exposure and lung cancer cells were also found to uptake magnetic nanoparticles rapidly in preliminary experiments. The lung cells were pretreated with different metabolic inhibitors. Our results revealed that low temperature disturbed the uptake of magnetic nanoparticles into the cells. Metabolic inhibitors also prevented the delivery of the materials into cells. Use of TEM clearly demonstrated that uptake of the nanoparticles was mediated through endosomes. Taken together, our results demonstrate that magnetic nanoparticles can be internalized into the cells through an energy-dependent endosomal-lysosomal mechanism
UV-Vis spectroscopic characterization of nanomaterials in aqueous media
The physicochemical characterization of nanomaterials (NMs) is often an analytical challenge, due to their small size (at least one dimension in the nanoscale, i.e. 1–100 nm), dynamic nature, and diverse properties. At the same time, reliable and repeatable characterization is paramount to ensure safety and quality in the manufacturing of NM-bearing products. There are several methods available to monitor and achieve reliable measurement of nanoscale-related properties, one example of which is Ultraviolet-Visible Spectroscopy (UV-Vis). This is a well-established, simple, and inexpensive technique that provides non-invasive and fast real-time screening evaluation of NM size, concentration, and aggregation state. Such features make UV-Vis an ideal methodology to assess the proficiency testing schemes (PTS) of a validated standard operating procedure (SOP) intended to evaluate the performance and reproducibility of a characterization method. In this paper, the PTS of six partner laboratories from the H2020 project ACEnano were assessed through an interlaboratory comparison (ILC). Standard gold (Au) colloid suspensions of different sizes (ranging 5–100 nm) were characterized by UV-Vis at the different institutions to develop an implementable and robust protocol for NM size characterization
Nanotechnology and Nanotoxicology in Retinopathy
Nanoparticles are nanometer-scaled particles, and can be utilized in the form of nanocapsules, nanoconjugates, or nanoparticles themselves for the treatment of retinopathy, including angiogensis-related blindness, retinal degeneration, and uveitis. They are thought to improve the bioavailability in the retina and the permeability of therapeutic molecules across the barriers of the eye, such as the cornea, conjunctiva, and especially, blood-retinal barriers (BRBs). However, consisting of multiple neuronal cells, the retina can be the target of neuronal toxicity of nanoparticles, in common with the central and peripheral nervous system. Furthermore, the ability of nanoparticles to pass through the BRBs might increase the possibility of toxicity, simultaneously promoting distribution in the retinal layers. In this regard, we discussed nanotechnology and nanotoxicology in the treatment of retinopathy
CRT-138 Impact of Trimetazidine Treatment on 5-year Clinical Outcomes in Patients with Significant Coronary Artery Spasm; A Propensity Score Matching Study
Determination of Malignant and Invasive Predictors in Branch Duct Type Intraductal Papillary Mucinous Neoplasms of the Pancreas: A Suggested Scoring Formula
Prediction of malignancy or invasiveness of branch duct type intraductal papillary mucinous neoplasm (Br-IPMN) is difficult, and proper treatment strategy has not been well established. The authors investigated the characteristics of Br-IPMN and explored its malignancy or invasiveness predicting factors to suggest a scoring formula for predicting pathologic results. From 1994 to 2008, 237 patients who were diagnosed as Br-IPMN at 11 tertiary referral centers in Korea were retrospectively reviewed. The patients' mean age was 63.1 ± 9.2 yr. One hundred ninty-eight (83.5%) patients had nonmalignant IPMN (81 adenoma, 117 borderline atypia), and 39 (16.5%) had malignant IPMN (13 carcinoma in situ, 26 invasive carcinoma). Cyst size and mural nodule were malignancy determining factors by multivariate analysis. Elevated CEA, cyst size and mural nodule were factors determining invasiveness by multivariate analysis. Using the regression coefficient for significant predictors on multivariate analysis, we constructed a malignancy-predicting scoring formula: 22.4 (mural nodule [0 or 1]) + 0.5 (cyst size [mm]). In invasive IPMN, the formula was expressed as invasiveness-predicting score = 36.6 (mural nodule [0 or 1]) + 32.2 (elevated serum CEA [0 or 1]) + 0.6 (cyst size [mm]). Here we present a scoring formula for prediction of malignancy or invasiveness of Br-IPMN which can be used to determine a proper treatment strategy
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