Multilayer fabrication of unobtrusive poly(dimethylsiloxane) nanobrush for tunable cell adhesion

Precise modulation of polymer brush in its thickness and grafting density can cause unexpected cell behaviors and regulated bioactivities. Herein, a nanoscale poly(dimethylsiloxane) (PDMS) brush was employed to use as a controllable material for cell adhesion. Facile fabrication of ultrathin monolayer PDMS nanobrush on an underlying substrate facilitated regaining cell adhesion through long-range cell attractive forces such as the van der Waals forces. We showed that cell adhesion is diminished by increasing the number of nanobrush layers, causing a gradual decrease of the effectiveness of the long-range force. The result demonstrates that ultrathin PDMS nanobrush can either promote or inhibit cell adhesion, which is required for various biomedical fields such as tissue-engineering, anti-fouling coating, and implantable biomaterials and sensors

Deep learning for prediction of mechanism in acute ischemic stroke using brain diffusion magnetic resonance image

Background Acute ischemic stroke is a disease with multiple etiologies. Therefore, identifying the mechanism of acute ischemic stroke is fundamental to its treatment and secondary prevention. The Trial of Org 10172 in Acute Stroke Treatment classification is currently the most widely used system, but it often has a limitations of classifying unknown causes and inadequate inter-rater reliability. Therefore, we attempted to develop a three-dimensional (3D)-convolutional neural network (CNN)-based algorithm for stroke lesion segmentation and subtype classification using only the diffusion and apparent diffusion coefficient information of patients with acute ischemic stroke. Methods This study included 2,251 patients with acute ischemic stroke who visited our hospital between February 2013 and July 2019. Results The segmentation model for lesion segmentation in the training set achieved a Dice score of 0.843±0.009. The subtype classification model achieved an average accuracy of 81.9%, with accuracies of 81.6% for large artery atherosclerosis, 86.8% for cardioembolism, 72.9% for small vessel occlusion, and 86.3% for control. Conclusion We developed a model to predict the mechanism of cerebral infarction using diffusion magnetic resonance imaging, which has great potential for identifying diffusion lesion segmentation and stroke subtype classification. As deep learning systems are gradually developing, they are becoming useful in clinical practice and applications

Physicochemical factors that affect electroporation of lung cancer and normal cell lines

Electroporation is used for cancer therapy to efficiently destroy cancer tissues by transferring anticancer drugs into cancer cells or by irreversible tumor ablation without resealing pores. There is growing interest in the electroporation method for the treatment of lung cancer, which has the highest mortality rate among cancers. Improving the cancer cell selectivity has the potential to expand its use. However, the factors that influence the cell selectivity of electroporation are debatable. We aimed to identify the important factors that influence the efficiency of electroporation in lung cells. The electropermeabilization of lung cancer cells (H460, A549, and HCC1588) and normal lung cells (MRCS, WI26 and L132) was evaluated by the transfer of fluorescence dyes. We found that membrane permeabilization increased as cell size, membrane stiffness, resting transmembrane potential, and lipid cholesterol ratio increased. Among them, lipid composition was found to be the most relevant factor in the electroporation of lung cells. Our results provide insight into the differences between lung cancer cells and normal lung cells and provide a basis for enhancing the sensitivity of lung cancers cells to electroporation. (C) 2019 Elsevier Inc. All rights reserved.N

Development of a Rating System for Digestive System Impairments: Korean Academy of Medical Sciences Guideline

A systematic and effective welfare system for people with digestive system impairments is required. In Korea, an objective and scientific rating guideline does not exist to judge the digestive system impairments. Whether the impairments exist or not and the degree of it need to be examined. Thus, with these considerations we need a scientific rating guideline for digestive system impairments to fit our cultural and social background. In 2007, a research team, for the development of rating impairment guidelines, was organized under the supervision of Korean Academy of Medical Sciences. The rating guidelines for digestive system impairments was classified into upper and lower gastrointestinal tracts impairments and liver impairment. We developed objective rating guidelines for the upper gastrointestinal tract, the impairment generated after surgery for the stomach, duodenum, esophagus, and for the lower gastrointestinal tract, the impairment generated after construction and surgery for colon, rectum, anus, and intestinal stomas. We tried to make the rating impairment guidelines to include science, objectivity, convenience, rationality, and actuality. We especially emphasized objectivity as the most important value. We worked to make it easy and convenient to use for both the subjects who received the impairment ratings and the doctors who will give the ratings

Percutaneous Vertebroplasty and Facet Joint Block

It is surprising that about 24% of patients with benign osteoporotic vertebral fracture die within a year from respiratory infection and urinary tract infection because of coughing and voiding difficulties, depending on the sites of compression fractures. We reviewed 500 patients on whom percutaneous vertebroplasty (PVP) was performed, at 612 levels in terms of patient selection, operation technique, medication, and clinical outcomes during the follow-up course for 2 yr study period. To confirm the most painful level among the multiple fracture sites, physical examination after facet joint block under the fluoroscope was the most reliable method. The mean total lumbar spine fracture threshold of bone mineral density was 0.81±0.05 g/cm2. The mean changes of numeric rating scale scores, Oswestry Disability Index except sex life, and Karnofsky performance status were -72.00, -83.50 and +60.62% in the osteoporosis group and -51.89, -45.02, and 69.03% in the tumor group. Complications related to the procedure were lateral spinal cord damage, transient paresthesia and transient hypotension. PVP with facet joint block is a profitable method for the vertebral compression fracture because of low risk and short duration of procedure with a high chance to result in pain relief and early mobilization

Multifunctional nanoparticles as a tissue adhesive and an injectable marker for image-guided procedures

Tissue adhesives have emerged as an alternative to sutures and staples for wound closure and reconnection of injured tissues after surgery or trauma. Owing to their convenience and effectiveness, these adhesives have received growing attention particularly in minimally invasive procedures. For safe and accurate applications, tissue adhesives should be detectable via clinical imaging modalities and be highly biocompatible for intracorporeal procedures. However, few adhesives meet all these requirements. Herein, we show that biocompatible tantalum oxide/silica core/shell nanoparticles (TSNs) exhibit not only high contrast effects for real-time imaging but also strong adhesive properties. Furthermore, the biocompatible TSNs cause much less cellular toxicity and less inflammation than a clinically used, imageable tissue adhesive (that is, a mixture of cyanoacrylate and Lipiodol). Because of their multifunctional imaging and adhesive property, the TSNs are successfully applied as a hemostatic adhesive for minimally invasive procedures and as an immobilized marker for image-guided procedures.

Correlation of Vascular Endothelial Growth Factor-D Expression and VEGFR-3-Positive Vessel Density with Lymph Node Metastasis in Gastric Carcinoma

Lymph node metastasis is an important prognostic factor in gastric cancer. Vascular endothelial growth factor-D (VEGF-D) is a lymphangiogenic growth factor that activates VEGF receptor (VEGFR)-3, a receptor expressed in the lymphatic endothelium. We investigated the clinical value of VEGF-D expression and VEGFR-3 positive vessel density in gastric carcinoma with regard to lymphangiogenesis. Immunohistochemical staining was used to determine the expression of VEGF-D and VEGFR-3 in specimens from 104 cases of resected gastric cancer. VEGF-D expression was observed in 62.5% of the gastric cancers and in 9.6% of the non-neoplastic gastric tissue. The VEGFR-3-positive vessel density was significantly greater in the VEGFD positive group than the negative group. VEGF-D expression was significantly associated with lymph node metastasis, increased serum CEA levels, and the non-signet ring cell type. The VEGFR-3-positive vessel density was correlated with tumor size, lymphatic invasion, and lymph node metastasis. The VEGF-D expression and high VEGFR-3-positive vessel density were significant poor prognostic factors for relapse-free survival. These results suggest that VEGF-D and VEGFR-3-positive vessel density are potential molecular markers that predict lymphatic involvement in gastric carcinoma

Changes in Sensitization Rate to Weed Allergens in Children with Increased Weeds Pollen Counts in Seoul Metropolitan Area

The prevalence of allergic diseases in children has increased for several decades. We evaluated the correlation between pollen count of weeds and their sensitization rate in Seoul, 1997-2009. Airborne particles carrying allergens were collected daily from 3 stations around Seoul. Skin prick tests to pollen were performed on children with allergic diseases. Ragweed pollen gradually increased between 1999 and 2005, decreased after 2005 and plateaued until 2009 (peak counts, 67 in 2003, 145 in 2005 and 83 grains/m3/day in 2007). Japanese hop pollen increased between 2002 and 2009 (peak counts, 212 in 2006 and 492 grains/m3/day in 2009). Sensitization rates to weed pollen, especially ragweed and Japanese hop in children with allergic diseases, increased annually (ragweed, 2.2% in 2000 and 2.8% in 2002; Japanese hop, 1.4% in 2000 and 1.9% in 2002). The age for sensitization to pollen gradually became younger since 2000 (4 to 6 yr of age, 3.5% in 1997 and 6.2% in 2009; 7 to 9 yr of age, 4.2% in 1997 and 6.4% in 2009). In conclusion, sensitization rates for weed pollens increase in Korean children given increasing pollen counts of ragweed and Japanese hop