987 research outputs found
Enhancement of angiogenic and vasculogenic potential of endothelial progenitor cells by haptoglobin
AbstractEndothelial progenitor cells (EPCs) were transfected with the haptoglobin (Hp) gene to investigate the effect of Hp on cell function. Hp potentiated the gene expression of various pro-angiogenic factors in the EPCs. The Hp-modified EPCs also increased in vitro tube formation on Matrigel compared with control cells. In hindlimb ischaemia models, Hp–EPCs showed a greater ability for improving blood perfusion and recovery from ischaemic injury. These results indicate that Hp improves EPC function in neovasculogenesis, which suggests that ex vivo modification of EPCs with the Hp gene can be applied to the treatment of vascular damage
Analysis of recent climate change over the Arctic using ERA-Interim reanalysis data
This study investigates recent climate change over the Arctic and its link to the mid-latitudes using the ERA-Interim global atmospheric reanalysis data from the European Center for Medium-Range Weather Forecast (ECMWF). Since 1979, substantial surface warming, associated with the increase in anthropogenic greenhouse gases, has occurred over the Arctic. The greatest warming in winter has taken place offshore in the Kara-Barents Sea, and is associated with the increase in turbulent heat fluxes from the marginal ice zone. In contrast to the marked warming over the Arctic Ocean in winter, substantial cooling appears over Siberia and eastern Asia, linked to the reduction of Arctic sea ice during the freezing season (September–March). However, in summer, very little change is observed in surface air temperature over the Arctic because increased radiative heat melts the sea ice and the amount of turbulent heat gain from the ocean is relatively small. The heat stored in the upper ocean mixed layer in summer with the opening of the Arctic Ocean is released back to the atmosphere as turbulent heat fluxes during the autumn and through to the following spring. This warming of the Arctic and the reduced sea ice amplifies surface cooling over Siberia and eastern Asia in winter
Systemic chemotherapy for treatment of advanced small bowel adenocarcinoma with prognostic factor analysis: retrospective study
<p>Abstract</p> <p>Background</p> <p>We sought to evaluate prognostic factors affecting overall survival (OS), and to investigate the role of palliative chemotherapy using propensity score-based weighting, in patients with advanced small bowel adenocarcinoma (SBA).</p> <p>Methods</p> <p>Data from a total of 91 patients diagnosed with advanced SBA at the Asan Medical Center between January 1989 and December 2009 were retrospectively analyzed. Patients were split into two groups, those who did and did not receive palliative chemotherapy.</p> <p>Results</p> <p>Overall, 81 patients (89.0%) died, at a median survival time of 6.6 months (95% confidence interval [CI], 5.5 - 7.5 months). The 40 patients receiving chemotherapy showed overall response and disease control rates of 11.1% and 37.0%, respectively, with OS and progression-free survival (PFS) of 11.8 months (95% CI, 4.6 - 19.0 months) and 5.7 months (95% CI, 3.5 - 8.0 months), respectively. The 41 patients who did not receive chemotherapy had an OS of 4.1 months (95% CI, 3.1 - 5.1 months) and a PFS of 1.3 months (95% CI, 0.8 - 1.7 months). Multivariate analysis showed that lack of tumor resection, non-prescription of chemotherapy, liver metastasis, and intra-abdominal lymph node metastasis, were all independently associated with poor survival outcomes. After inverse probability of treatment weighting (IPTW) adjustment, the group that did not receive chemotherapy was at a significantly higher risk of mortality (HR 3.44, 95% CI 2.03 - 5.83, p < 0.001) than were patients receiving chemotherapy.</p> <p>Conclusion</p> <p>Palliative chemotherapy may improve survival outcomes in patients with advanced SBA.</p
Evaluation of Electromagnetic Exposure in Wireless Power Transfer Systems for Electric Vehicles
In wireless power transfer (WPT) systems, the electromagnetic fields generated by a charging module may exceed the limits set by international safety guidelines. This is a matter of concern for the safety of users of high-power WPT systems, such as electric vehicles (EVs). To address this issue, this study designed a stationary WPT system for EV charging. Furthermore, the dosimetry of the system was evaluated for two exposure scenarios. Electromagnetic field data obtained using the electromagnetic field analysis tool were employed to derive the induced quantities in the human body using the impedance method. In addition, the obtained results were compared to the values recommended by international guidelines (International Commission on Non-Ionizing Radiation Protection)
Vascular differentiation of multipotent spermatogonial stem cells derived from neonatal mouse testis
We previously reported the successful establishment of embryonic stem cell (ESC)-like multipotent spermatogonial stem cells (mSSCs) from neonatal mouse testis. Here, we examined the ability of mSSCs to differentiate into vascular endothelial cells and smooth muscle cells, and compared to that of mouse ESCs. We used real-time reverse transcriptase polymerase chain reaction and immunohistochemistry to examine gene expression profiles of mSSCs and ESCs during in vitro vascular differentiation. Both mSSCs and ESCs exhibited substantial increase in the expression of mesodermal markers, such as Brachyury, Flk1, Mesp1, Nkx2.5, and Islet1, and a decrease in the expression of pluripotency markers, such as Oct3/4 and Nanog during the early stage of differentiation. The mRNA levels of vascular endothelial (VE)-cadherin and CD31 gradually increased in both differentiated mSSCs and ESCs. VE-cadherin- or CD31-positive cells formed sprouting branch-like structures, as observed during embryonic vascular development. At the same time, vascular smooth muscle cell-specific markers, such as myocardin and α-smooth muscle actin (SMA), were also highly expressed in differentiated mSSCs and ESCs. Immunocytochemical analysis revealed that the differentiated cells expressed both α-SMA and SM22-α proteins, and exhibited the intracellular fibril structure typical of smooth muscle cells. Overall, our findings showed that mSSCs have similar vascular differentiation abilities to those of ESCs, suggesting that mSSCs may be an alternative source of autologous pluripotent stem cells for vascular regeneration
Effects of Delay in the Snap Freezing of Colorectal Cancer Tissues on the Quality of DNA and RNA
Combined 18F-FDG PET/CT Imaging for the Initial Evaluation of Glottic Cancer
ObjectivesThe primary aim of this study was to determine whether 18F-FDG-PET/CT (PET/CT) scans provide additional diagnostic information in addition to the direct laryngoscopic examination (L/E) and contrast-enhanced CT (CT) in patients with glottic cancer during the initial evaluation.MethodsFifty-five consecutive patients with glottic cancer of the larynx that had L/E, CT and PET/CT were enrolled. The diagnostic value of each modality was compared for their accuracy in predicting the extent of the primary tumors on sub-site based analysis and the final tumor staging. The reference standards were either the surgical pathology findings or clinical/radiological follow-up outcome. Changes in patient care based on PET/CT results were compared with the treatment decisions based on L/E with CT.ResultsFor primary tumor sub-site based analysis, the sensitivity was significantly higher for L/E (92.8%) than for PET/CT (79.4%, P=0.028). The comparisons between L/E vs. CT and CT vs. PET/CT did not reach statistical significance. As an initial tumor-staging method the L/E had a diagnostic accuracy of 76.4%, compared to 61.8% for CT and 41.8% for PET/CT. The L/E and CT were better than the PET/CT (P=0.0009 and 0.049) for the initial TNM staging. PET/CT scanning changed the clinical decision-making based on the L/E with CT results in 12.7% of cases, of whom 5.5% had no additional PET/CT related benefit.ConclusionThe results of this study showed that PET/CT imaging added no clinical information benefit compared to the L/E and CT for the initial evaluation of patients with glottic cancer
Impact of successful restoration of sinus rhythm in patients with atrial fibrillation and acute heart failure: Results from the Korean Acute Heart Failure registry
Background: Restoring and maintaining sinus rhythm (SR) in patients with atrial fibrillation (AF) failed to show superior outcomes over rate control strategies in prior randomized trials. However, there is sparse data on their outcomes in patients with acute heart failure (AHF).Methods: From December 2010 to February 2014, 5,625 patients with AHF from 10 tertiary hospitals were enrolled in the Korean Acute Heart Failure registry, including 1,961 patients whose initial electrocardiogram showed AF. Clinical outcomes of patients who restored SR by pharmacological or electrical cardioversion (SR conversion group, n = 212) were compared to those of patients who showed a persistent AF rhythm (AF persistent group, n = 1,662).Results: All-cause mortality both in-hospital and during the follow-up (median 2.5 years) were significantly lower in the SR conversion group than in the AF persistent group after adjustment for risk factors (adjusted hazard ratio [HR]; 95% confidence interval [CI] = 0.26 [0.08–0.88], p = 0.031 and 0.59 [0.43–0.82], p = 0.002, for mortality in-hospital and during follow-up, respectively). After 1:3 propensity score matching (SR conversion group = 167, AF persistent group = 501), successful restoration of SR was associated with lower all-cause mortality (HR [95% CI] = 0.68 [0.49–0.93], p = 0.015), heart failure rehospitalization (HR [95% CI] = 0.66 [0.45–0.97], p = 0.032), and composite of death and heart failure rehospitalization (HR [95% CI] = 0.66 [0.51–0.86], p = 0.002).Conclusions: Patients with AHF and AF had significantly lower mortality in-hospital and during follow-up if rhythm treatment for AF was successful, underscoring the importance of restoring SR in patients with AHF
The impact of dose of the angiotensin-receptor blocker valsartan on the post-myocardial infarction ventricular remodeling: study protocol for a randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Angiotensin-converting enzyme inhibitors and the angiotensin-receptor blocker valsartan ameliorate ventricular remodeling after myocardial infarction (MI). Based on previous clinical trials, a maximum clinical dose is recommended in practical guidelines. Yet, has not been clearly demonstrated whether the recommended dose is more efficacious compared to the lower dose that is commonly used in clinical practice.</p> <p>Method/Design</p> <p>Valsartan in post-MI remodeling (VALID) is a randomized, open-label, single-blinded multicenter study designed to compare the efficacy of different clinical dose of valsartan on the post-MI ventricular remodeling. This study also aims to assess neurohormone change and clinical parameters of patients during the post-infarct period. A total of 1116 patients with left ventricular dysfunction following the first episode of acute ST-elevation MI are to be enrolled and randomized to a maximal tolerable dose (up to 320 mg/day) or usual dose (80 mg/day) of valsartan for 12 months in 2:1 ratio. Echocardiographic analysis for quantifying post-MI ventricular remodeling is to be conducted in central core laboratory. Clinical assessment and laboratory test are performed at fixed times.</p> <p>Discussion</p> <p>VALID is a multicenter collaborative study to evaluate the impact of dose of valsartan on the post-MI ventricular remodeling. The results of the study provide information about optimal dosing of the drug in the management of patients after MI. The results will be available by 2012.</p> <p>Trial registration</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT01340326">NCT01340326</a></p
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