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61.
Immune reactions of lymphocytes and macrophages against PEG-grafted pancreatic islets 总被引:4,自引:0,他引:4
Graft rejection is the major limiting factor in islet transplantation and is closely related with the recruitment and activation of T cells and macrophages against the graft. To reduce the immunogenicity of islets, we have grafted biocompatible polyethylene glycol (PEG) onto the collagen capsule of islets without changing the morphology and function of islets. In this study, we evaluated whether the grafted PEG molecules on the collagen capsule of islet could prevent the activation of immune cells, and investigated factors that are mainly related to the immune reaction in vitro. During the co-culture with lymphocytes, the morphology and viability of PEG-grafted islets were not damaged, and the amounts of IL-2 and TNF-alpha secreted from lymphocytes co-cultured with PEG-grafted islets were significantly lower than that of free islets. However, when both kinds of islets were cultured with macrophages, there were no significant differences in morphology, viability and the secreted amounts of cytokines and nitric oxide. In conclusion, the grafted PEG could inhibit activation of lymphocytes, which are essential in initiating the graft rejection process. However, the grafted PEG molecules could not completely prevent the infiltration of cytotoxic molecules into the islets. 相似文献
62.
Accurate preoperative staging is essential in determining the optimal therapeutic planning for individual patients. The computed
tomography (CT) in the preoperative staging of colorectal cancer, even if controversial, may be useful for planning surgery
and/or neoadjuvant therapy, particularly when local tumor extension into adjacent organs or distant metastases are detected.
There have been significant changes in the CT technology with the advent of multi-detector row CT (MDCT) scanner. Advances
in CT technology have raised interest in the potential role of CT for detection and staging of colorectal cancer. In recent
studies, MDCT with MPR images has shown promising accuracy in the evaluation of local extent and nodal involvement of colorectal
cancer. Combined PET/CT images have significant advantages over either alone because it provides both functional and anatomical
data. Therefore, it is natural to expect that PET/CT would improve the accuracy of preoperative staging of colorectal cancer.
The most significant additional information provided by PET/CT relates to the accurate detection of distant metastases. For
the evaluation of patients with colorectal cancer, CT has relative advantages over PET/CT in regard to the depth of tumor
invasion through the wall, extramural extension, and regional lymph node metastases. PET/CT should be performed on selected
patients with suggestive but inconclusive metastatic lesions with CT. In addition, PET/CT with dedicated CT protocols, such
as contrast-enhanced PET/CT and PET/CT colonography, may replace the diagnostic CT for the preoperative staging of colorectal
cancer. 相似文献
63.
S. K. BRÆKKAN E. B. MATHIESEN I. NJØLSTAD T. WILSGAARD J. STØRMER J. B. HANSEN 《Journal of thrombosis and haemostasis》2008,6(11):1851-1857
Summary. Background: Recent studies indicate that arterial cardiovascular diseases and venous thromboembolism (VTE) share common risk factors. A family history of myocardial infarction (MI) is a strong and independent risk factor for future MI. Objectives: The purpose of the present study was to determine the impact of cardiovascular risk factors, including family history of MI, on the incidence of VTE in a prospective, population‐based study. Patients and methods: Traditional cardiovascular risk factors and family history of MI were registered in 21 330 subjects, aged 25–96 years, enrolled in the Tromsø study in 1994–95. First‐lifetime VTE events during follow‐up were registered up to 1 September 2007. Results: There were 327 VTE events (1.40 per 1000 person‐years), 138 (42%) unprovoked, during a mean of 10.9 years of follow‐up. In age‐ and gender‐adjusted analysis, age [hazard ratio (HR) per decade, 1.97; 95% confidence interval (CI), 1.82–2.12], gender (men vs. women; HR, 1.25; 95% CI, 1.01–1.55), body mass index (BMI; HR per 3 kg m?2, 1.21; 95% CI, 1.13–1.31), and family history of MI (HR, 1.31; 95% CI, 1.04–1.65) were significantly associated with VTE. Family history of MI remained a significant risk factor for total VTE (HR, 1.27; 95% CI, 1.01–1.60) and unprovoked VTE (HR, 1.46; 95% CI, 1.03–2.07) in multivariable analysis. Blood pressure, total cholesterol, HDL‐cholesterol, triglycerides, and smoking were not independently associated with total VTE. Conclusions: Family history of MI is a risk factor for both MI and VTE, and provides further evidence of a link between venous and arterial thrombosis. 相似文献
64.
[Purpose] The purpose of this study was to compare shoulder stabilization muscle
activities according to postural changes during flexi-bar exercise. [Subjects] The
subjects included 18 students (10 males, 8 females) at B University. [Methods] The
subjects performed the following flexi-bar exercises: 1) medio-lateral oscillation with
the 90° shoulder abduction, with the hand in the neutral position; 2) dorso-ventral
oscillation with 90° shoulder flexion, with the hand in the neutral position; 3)
superior-inferior oscillation with 90° shoulder flexion, with the 80° hand pronation.
[Results] The activity of the serratus anterior showed significant differences between
each position; however, activities of the upper trapezius and middle trapezius were not
significantly different. [Conclusion] The results of this study indicate that posture
control is important for selective strengthening of the serratus anterior muscle during
flexi-bar exercises.Key words: Flexi-bar exercise, Shoulder stabilization, Muscle activity 相似文献
65.
We investigated the effects of Pd precursors and preparation methods on the physicochemical properties and performance of Pd/TiO2 catalysts in the photocatalytic degradation of methyl violet. To confirm the influence of the precursors, Pd/TiO2 catalysts were prepared via chemical reduction (CR) using four different Pd precursors. Additionally, to determine the effects of preparation methods, Pd/TiO2 catalysts were fabricated using K2PdCl4 precursor via three different methods: CR, deposition–precipitation (DP), and impregnation. The CO chemisorption results showed that the catalyst prepared via DP using the K2PdCl4 precursor, i.e., Pd/TiO2_K_DP, displayed the highest Pd dispersion of 12.42% owing to the stable formation of Pd(OH)2, which strongly interacted with the –OH groups on the TiO2 support. Although the catalyst prepared via CR using the Pd(NH3)4Cl2·H2O (PA) precursor, i.e., Pd/TiO2_PA_CR, had the lowest Pd dispersion of 0.7%, it exhibited the highest absorption of 26% after 30 min in the dark. It was found that high Pd2+/Pd0 ratio in dark conditions adversely affected the absorption of MV owing to electrostatic repulsion between the cationic dyes and metal nanoparticles. However, the Pd dispersion and the specific surface area played a key role in the photocatalytic activity under UV irradiation. Pd/TiO2_K_CR with higher Pd dispersion showed the highest photocatalytic activity and reaction rate of 0.0212 min−1.We investigated the effects of Pd precursors and preparation methods on the physicochemical properties and performance of Pd/TiO2 catalysts in the photocatalytic degradation of methyl violet. 相似文献
66.
67.
Jeong Yoon Jang Jae Gun Lee In-Kyung Jeong Kyu Jeong Ahn Ho Yeon Chung Hyung-In Yang Sang-Hoon Lee 《Rheumatology international》2009,29(11):1359-1362
Post-pregnancy osteoporosis is not a common disease and is hard to diagnosis because their specific situation is post-partum
and lactation. It commonly occurs on lumbar spine within a few months after the birth of a patient’s first child and it could
lead to be fracture after minor trauma. Although its etiology is not clear, it would not be of sufficient magnitude to cause
fractures unless the woman already had a substantial decrease in bone mass. Also, it is rare to be combined with ankylosing
spondylitis. Ankylosing spondylitis has a higher risk of osteoporosis and vertebral fracture which increased with the duration
of disease. We report a case of post-pregnancy osteoporosis with multiple spinal compression fracture in association of ankylosing
spondylitis. 相似文献
68.
69.
Uyenchi N Le Hyung-Seok Kim Jin-Sook Kwon Mi Yeon Kim Vu H Nguyen Sheng Nan Jiang Byeong-Il Lee Yeongjin Hong Myung Geun Shin Joon Haeng Rhee Hee-Seung Bom Youngkeun Ahn Sanjiv S Gambhir Hyon E Choy Jung-Joon Min 《Molecular therapy》2011,19(5):951-959
Optimization of the specific affinity of cardiac delivery vector could significantly improve the efficiency of gene/protein delivery, yet no cardiac vectors to date have sufficient target specificity for myocardial infarction (MI). In this study, we explored bacterial tropism for infarcted myocardium based on our previous observations that certain bacteria are capable of targeting the hypoxic regions in solid tumors. Out of several Escherichia coli or Salmonella typhimurium strains, the S. typhimurium defective in the synthesis of ppGpp (ΔppGpp S. typhimurium) revealed accumulation and selective proliferation in the infarcted myocardium without spillover to noncardiac tissue. The Salmonellae that were engineered to express a variant of Renilla luciferase gene (RLuc8), under the control of the E. coli arabinose operon promoter (PBAD), selectively targeted and delivered RLuc8 in the infarcted myocardium only upon injection of -arabinose. An examination of the infarct size before and after infection, and estimations of C-reactive protein (CRP) and procalcitonin indicated that intravenous injection of ΔppGpp S. typhimurium did not induce serious local or systemic immune reactions. This current proof-of-principle study demonstrates for the first time the capacity of Salmonellae to target infarcted myocardium and to serve as a vehicle for the selective delivery of therapeutic agents in MI. 相似文献
70.