1,955 research outputs found

    Mesenchymal Stem Cells Improve Wound Healing In Vivo via Early Activation of Matrix Metalloproteinase-9 and Vascular Endothelial Growth Factor

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    We investigated the effects of mesenchymal stem cells (MSCs) on wound healing using a three-dimensional (3D) collagen gel scaffold. Three circular full-thickness skin defects were created on the back of Sprague-Dawley rats. One site was covered with a 3D collagen gel containing 2 × 106 MSCs (MSCs+/3D collagen+). Another site was replaced with a 3D collagen gel without MSCs and the third site was left empty. The wound size was significantly reduced in the MSCs+/3D collagen+ sites. MSCs+/3D collagen+ sites exhibited the most neovascularization. FISH showed that Y-chromosome possessing cells were found within the dermis of MSCs+/3D collagen+ sites. Gelatin zymography revealed that the most intense expression of MMP-9 was detected early in the MSCs+/3D collagen+ sites. Our results indicate that MSCs upregulate the early expression of MMP-9 which induces the early mobilization of VEGF. Thus, MSCs appear to accelerate significantly wound healing via early activation of MMP-9 and VEGF

    Indium as an efficient ohmic contact to N-face n-GaN of GaN-based vertical light-emitting diodes

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    We propose indium (In), a low work function and nitride-forming element, as an efficient ohmic contact layer to N-face n-GaN. While conventional Al-based ohmic contacts show severe degradation after annealing at 300 C, In-based ohmic contacts display considerable improvement in contact resistivity. The annealing-induced enhancement of ohmic behavior in In-based contacts is attributed to the formation of an InN interfacial layer, which is supported by x-ray photoemission spectroscopy measurements. These results suggest that In is of particular importance for application as reliable ohmic contacts to n-GaN of GaN-based vertical light-emitting diodes.open3

    The Risk of Type 2 Diabetes Mellitus according to Changes in Obesity Status in Late Middle-Aged Adults: A Nationwide Cohort Study of Korea

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    Background Although obesity is a well-known risk factor of type 2 diabetes mellitus (T2DM), there is scant data on discriminating the contribution of previous obesity and recent weight gain on developing T2DM. Methods We analyzed the Korean National Health Insurance Service-Health Screening Cohort data from 2002 to 2015 where Korean residents underwent biennial health checkups. Participants were classified into four groups according to their obesity status (body mass index [BMI] ≥25 kg/m2) before and after turning 50 years old: maintaining normal (MN), becoming obese (BO), becoming normal (BN), and maintaining obese (MO). Cox proportional hazards regression model was used to estimate the risk of T2DM factoring in the covariates age, sex, BMI, presence of impaired fasting glucose or hypertension, family history of diabetes, and smoking status. Results A total of 118,438 participants (mean age, 52.5±1.1 years; men, 45.2%) were prospectively evaluated for incident T2DM. A total of 7,339 (6.2%) participants were diagnosed with T2DM during a follow-up period of 4.8±2.6 years. Incidence rates of T2DM per 1,000 person-year were 9.20 in MN, 14.81 in BO, 14.42 in BN, 21.38 in MO. After factoring in covariates, participants in the groups BN (adjusted hazard ratio [aHR], 1.15; 95% confidence interval [CI], 1.04 to 1.27) and MO (aHR, 1.14; 95% CI, 1.06 to 1.24) were at increased risk of developing T2DM compared to MN, whereas BO (hazard ratio, 1.06; 95% CI, 0.96 to 1.17) was not. Conclusion Having been obese before 50 years old increased the risk of developing T2DM in the future, but becoming obese after 50 did not. Therefore, it is important to maintain normal weight from early adulthood to prevent future metabolic perturbations

    Molecular Subgroup Analysis of Clinical Outcomes in a Phase 3 Study of Gemcitabine and Oxaliplatin with or without Erlotinib in Advanced Biliary Tract Cancer

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    AbstractBACKGROUND: We previously reported that the addition of erlotinib to gemcitabine and oxaliplatin (GEMOX) resulted in greater antitumor activity and might be a treatment option for patients with biliary tract cancers (BTCs). Molecular subgroup analysis of treatment outcomes in patients who had specimens available for analysis was undertaken. METHODS: Epidermal growth factor receptor (EGFR), KRAS, and PIK3CA mutations were evaluated using peptide nucleic acid–locked nucleic acid polymerase chain reaction clamp reactions. Survival and response rates (RRs) were analyzed according to the mutational status. Sixty-four patients (48.1%) were available for mutational analysis in the chemotherapy alone group and 61 (45.1%) in the chemotherapy plus erlotinib group. RESULTS: 1.6% (2/116) harbored an EGFR mutation (2 patients; exon 20), 9.6% (12/121) harbored a KRAS mutation (12 patients; exon 2), and 9.6% (12/118) harbored a PIK3CA mutation (10 patients, exon 9 and 2 patients, exon 20). The addition of erlotinib to GEMOX in patients with KRAS wild-type disease (n = 109) resulted in significant improvements in overall response compared with GEMOX alone (30.2% vs 12.5%, P = .024). In 95 patients with both wild-type KRAS and PIK3CA, there was evidence of a benefit associated with the addition of erlotinib to GEMOX with respect to RR as compared with GEMOX alone (P = .04). CONCLUSION: This study demonstrates that KRAS mutational status might be considered a predictive biomarker for the response to erlotinib in BTCs. Additionally, the mutation status of PIK3CA may be a determinant for adding erlotinib to chemotherapy in KRAS wild-type BTCs

    Health insurance system for hematologic diseases: what should we do?

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    Detection of distant metastasis to skeletal muscle by 18F-FDG-PET in a case of intrahepatic cholangiocarcinoma

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    Intrahepatic cholangiocarcinoma is a rare malignancy that originates from the epithelial cells of the intrahepatic bile ducts. Intrahepatic cholangiocarcinoma can metastasize in lymphatic chains, including the hepatoduodenal ligament, and it often invades adjacent organs or metastasizes to other visceral organs such as the lungs, bones, adrenal glands, and brain. However, distant skeletal muscle metastasis is very rare. Moreover, a metastatic skeletal muscle tumor rarely shows specific symptoms, making it difficult to identify in a routine examination. A 45-year-old man with a chief complaint of right upper quadrant abdominal pain was admitted to our hospital. Abdominal ultrasound and computed tomography with contrast enhancement showed a malignant mass in the right hepatic lobe, and 2-[18F] fluoro-2-deoxy-D-glucose positron-emission tomography revealed distant skeletal muscle metastases in the thorax and buttock. The patient underwent an ultrasound-guided percutaneous needle biopsy for the metastatic low-echo masses in the skeletal muscle

    Engineering PSU\u27s Future: An Interview with Dr. Rahmat Shoureshi

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    PSU’s ninth president, Dr. Rahmat Shoureshi (pronounced Shoe-re-she) is an experienced administrator and innovative academic who considers his work with students his greatest accomplishment. Shoureshi is a mechanical engineer who earned a master’s degree and a doctorate from the Massachusetts Institute of Technology. Shoureshi says PSU’s commitment to diversity, civic engagement and innovation persuaded him to join the university
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