997 resultados para CD-31


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Background Thromboxane synthase (TXS) metabolizes prostaglandin H2 into thromboxanes, which are biologically active on cancer cells. TXS over-expression has been reported in a range of cancers, and associated with angiogenesis and poor outcome. TXS has been identified as a potential therapeutic target in NSCLC. This study examines a link between TXS expression, angiogenesis, and survival in NSCLC. Methods TXS and VEGF metabolite levels were measured in NSCLC serum samples (n=46) by EIA. TXB2 levels were correlated with VEGF. A 204-patient TMA was stained for TXS, VEGF, and CD-31 expression. Expression was correlated with a range of clinical parameters, including overall survival. TXS expression was correlated with VEGF and CD-31. Stable TXS clones were generated and the effect of overexpression on tumor growth and angiogenesis markers was examined in-vitro and in-vivo (xenograft mouse model). Results Serum TXB2 levels were correlated with VEGF (p<0.05). TXS and VEGF were expressed to a varying degree in NSCLC tissue. TXS was associated with VEGF (p<0.0001) and microvessel density (CD-31; p<0.05). TXS and VEGF expression levels were higher in adenocarcinoma (p<0.0001) and female patients (p<0.05). Stable overexpression of TXS increased VEGF secretion in-vitro. While no significant association with patient survival was observed for either TXS or VEGF in our patient cohort, TXS overexpression significantly (p<0.05) increased tumor growth in-vivo. TXS overexpression was also associated with higher levels of VEGF, microvessel density, and reduced apoptosis in xenograft tumors. Conclusion TXS promotes tumor growth in-vivo in NSCLC, an effect which is at least partly mediated through increased tumor angiogenesis.

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Microneurovascular free muscle transfer with cross-over nerve grafts in facial reanimation Loss of facial symmetry and mimetic function as seen in facial paralysis has an enormous impact on the psychosocial conditions of the patients. Patients with severe long-term facial paralysis are often reanimated with a two-stage procedure combining cross-facial nerve grafting, and 6 to 8 months later with microneurovascular (MNV) muscle transfer. In this thesis, we recorded the long-term results of MNV surgery in facial paralysis and observed the possible contributing factors to final functional and aesthetic outcome after this procedure. Twenty-seven out of forty patients operated on were interviewed, and the functional outcome was graded. Magnetic resonance imaging (MRI) of MNV muscle flaps was done, and nerve graft samples (n=37) were obtained in second stage of the operation and muscle biopsies (n=18) were taken during secondary operations.. The structure of MNV muscles and nerve grafts was evaluated using histological and immunohistochemical methods ( Ki-67, anti-myosin fast, S-100, NF-200, CD-31, p75NGFR, VEGF, Flt-1, Flk-1). Statistical analysis was performed. In our studies, we found that almost two-thirds of the patients achieved good result in facial reanimation. The longer the follow-up time after muscle transfer the weaker was the muscle function. A majority of the patients (78%) defined their quality of life improved after surgery. In MRI study, the free MNV flaps were significantly smaller than originally. A correlation was found between good functional outcome and normal muscle structure in MRI. In muscle biopsies, the mean muscle fiber diameter was diminished to 40% compared to control values. Proliferative activity of satellite cells was seen in 60% of the samples and it tended to decline with an increase of follow-up time. All samples showed intramuscular innervation. Severe muscle atrophy correlated with prolonged intraoperative ischaemia. The good long-term functional outcome correlated with dominance of fast fibers in muscle grafts. In nerve grafts, the mean number of viable axons amounted to 38% of that in control samples. The grafted nerves characterized by fibrosis and regenerated axons were thinner than in control samples although they were well vascularized. A longer time between cross facial nerve grafting and biopsy sampling correlated with a higher number of viable axons. P75Nerve Growth Factor Receptor (p75NGFR) was expressed in every nerve graft sample. The expression of p75NGFR was lower in older than in younger patients. A high expression of p75NGFR was often seen with better function of the transplanted muscle. In grafted nerve Vascular Endothelial Growth Factor (VEGF) and its receptors were expressed in nervous tissue. In conclusion, most of the patients achieved good result in facial reanimation and were satisfied with the functional outcome. The mimic function was poorer in patients with longer follow-up time. MRI can be used to evaluate the structure of the microneurovascular muscle flaps. Regeneration of the muscle flaps was still going on many years after the transplantation and reinnervation was seen in all muscle samples. Grafted nerves were characterized by fibrosis and fewer, thinner axons compared to control nerves although they were well vascularized. P75NGFR and VEGF were expressed in human nerve grafts with higher intensity than in control nerves which is described for the first time.

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Merkel cell carcinoma (MCC) is a rare cutaneous malignancy that occurs predominantly on sun exposed skin areas. A new polyomavirus (MCPyV) was identified in MCC tumor tissues in 2008 suggesting that a viral infection might be an etiological factor. A typical MCC is a rapidly growing painless purple nodule. In its early stage it can be misjudged by its appearance as a cyst or abscess. Recurrences are common and approximately half of the patients will develop lymph node metastases and third of the patents will have distant metastases. It affects mostly elderly persons at an average age of 70 at the time of diagnosis. MCC was first described in 1972 and the first MCC patient in Finland was identified in 1983. MCC has been poorly recognized, but increased awareness and better diagnostic accuracy has increased the incidence since the early years. In this study, all cases with a notation of MCC during 1979 2008 were obtained from the Finnish Cancer Registry. Based on this data, the incidence is 0.11 for men and 0.12 for women. It is similar than that of other Nordic countries, but lower than in the USA. For clinical series, the files of patients diagnosed with MCC during 1983 2004 were reviewed, and the tissue samples were re-evaluated, if available (n=181). Third of the patients were men, and the most common site of the primary tumor was the head and neck (53%). The majority of the patients (86%) presented with a clinically node-negative (Stage I or II) disease, but the disease recurred in 38% of them. The treatment schemes were heterogeneous. No additional benefit from a wide margin (≥2 cm) was found compared to a margin of 0.1-1.9 cm, but intralesional excision was more often associated with local recurrence. None of the patients with Stage I-II disease who had received postoperative radiotherapy had local recurrence during the follow-up period. The 5-year relative survival ratio for Stage I disease was 68%, for Stage II 67%, for Stage III 16%, and for Stage IV 0%. The relative excess risk of death was significantly lower among women than among men. Some of these tissue samples were further analyzed for vascular invasion (n=126) by immunohistochemistry using vascular endothelial markers CD-31 and D2-40. Vascular invasion was seen in 93% of the samples and it was observed already in very small, <5mm tumors. The tissue samples were also analyzed for the presence of MCPyV by using a polymerase chain reaction (PCR) and quantitative PCR. MCPyV DNA was present in 80% of 114 samples studied. The patients with virus-positive tumors had better overall survival than patients with virus-negative tumors. Immunohistochemical analyses were performed for the expression of VEGFR-2 (n=21) and endostatin (n=19), but they had no prognostic value. Our results support the concept of treating MCC with margin-negative excision and radiotherapy to the tumor bed to reduce local recurrence. The finding of a high frequency of lymphovascular invasion reduces its value as a prognostic factor, but emphasizes the role of sentinel node biopsy even in very small primary MCC.

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Tese de mestrado em Engenharia Biomédica e Biofísica, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2015

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Therapy with stem cells has showed to be promising for acute kidney injury (AKI), although how it works is still controversial. Modulation of the inflammatory response is one possible mechanism. Most of published data relies on early time and whether the protection is still maintained after that is not known. Here, we analyzed whether immune modulation continues after 24 h of reperfusion. MSC were obtained from male Wistar rats. After 3-5 passages, cells were screened for CD73, CD90, CD44, CD45, CD29 and CD 31. In addition, MSC were submitted to differentiation in adipocyte and in osteocyte. AKI was induced by bilaterally clamping of renal pedicles for 60 min. Six hours after injury, MSC (2 x 105 cells) were administered intravenously. MSC-treated animals presented the lowest serum creatinine compared to non-treated animals (24 h: 1.3 +/- 0.21 vs. 3.23 +/- 0.89 mg/dl, p<0.05). The improvement in renal function was followed by a lower expression of IL-1b, IL-6 and TNF-alpha and higher expression of IL-4 and IL-10. However, 48 h after reperfusion, this cytokine profile has changed. The decrease in Th1 cytokines was less evident and IL-6 was markedly up regulated. PCNA analysis showed that regeneration occurs faster in kidney tissues of MSC-treated animals than in controls at 24 h. And also ratio of Bcl-2/Bad was higher at treated animals after 24 and 48 h. Our data demonstrated that the immunomodulatory effects of MSC occur at very early time point, changing the inflammation profile toward a Th2 profile. (C) 2009 Elsevier B.V. All rights reserved.

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Introduction: Venous thrombosis (VT) and inflammation are two closely related entities. In the present investigation we assessed whether there is a relation between genetic modifiers of the inflammatory response and the risk of VT. Materials and methods: 420 consecutive and unrelated patients with an objective diagnosis of deep VT and 420 matched controls were investigated. The frequencies of the following gene polymorphisms were determined in all subjects: TNF-α- 308 G/A, LT-α+ 252 A/G, IL-6-174 G/C, IL1-ra 86 bp VNTR, IL-10-1082 A/G and CD-31 125 C/G. Results: Overall odds ratio (OR) for VT related to TNF-α- 308 G/A, LT-α+ 252 A/G, IL-6-174 G/C, A1 allele (4 bp repeat) of the IL1-ra 86 bp VNTR, IL-10-1082 A/G and CD-31 125 C/G were respectively: 1.0 (CI95: 0.8-1.5), 1.3 (CI95: 1.0-1.7), 1.1 (CI95: 0.9-1.5), 1.6 (CI95: 1-2.5), 1.2 (CI95: 0.8-1.7) and 0.8 (CI95: 0.6-1.1). A possible interaction between polymorphisms was observed only for the co-inheritance of the mutant alleles of the LT-α+ 252 A/G and IL-10-1082 G/A polymorphisms (OR = 2; CI95: 1.1-3.8). The risk of VT conferred by factor V Leiden and FII G20210A was not substantially altered by co-inheritance with any of the cytokine gene polymorphisms. Conclusions: Cytokine gene polymorphisms here investigated did not significantly influence venous thrombotic risk. © 2006 Elsevier Ltd. All rights reserved.

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BACKGROUND AND AIMS: Well-differentiated neuro-endocrine ileal carcinoids are composed of serotonin-producing enterochromaffin (EC) cells. Life expectancy is determined by metastatic spread to the liver because medical treatment options are still very limited. Selective inhibition of angiogenesis or lymphangiogenesis might prevent tumour growth and metastatic spread. We examined the role of the vascular endothelial growth factors (VEGFs) A, B, C, D, and their receptors (VEGFRs) 1, 2, 3 in angiogenesis and lymphangiogenesis of ileal EC cell carcinoids with and without liver metastases. METHODS: The expression of various VEGFs and VEGFRs was determined by quantitative real-time RT-PCR in healthy mucosa, primary tumour, lymph node metastases and liver metastases of 25 patients with ileal EC cell carcinoids. Microvessel density (MVD) was determined by CD-31 staining in primary tumours and lymphatic vessel density (LVD) by LYVE-1 staining. VEGF expression levels, MVD, LVD, and patients' survival time were correlated using logistic regression and Kaplan-Meier survival analysis. RESULTS: VEGF-A was highly expressed with no difference between normal mucosa and tumours. VEGF-B and -D as well as VEGFR-1 and -2 expression levels were significantly increased in the tumours when compared to normal mucosa. Patients with liver metastasis, however, had a significantly lower expression of the factors A, B, and C and the receptors 2 and 3. MVD in primary tumours positively correlated with the expression of VEGF ligands and their receptors, except for VEGF-D. LVD did not correlate with any VEGF ligand or receptor. Interestingly, low expression levels of VEGF-B were associated with poor survival. CONCLUSION: Patients with more aggressive metastatic spreading had relatively decreased expression levels of VEGF ligands and receptors. Thus, anti-angiogenic therapy may not be a suitable target in metastatic ileal EC cell carcinoids.

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The purpose of this study was to characterize the effects of IL-6 on endothelial cells and to investigate the role of IL-6 in the angiogenesis of ovarian carcinomas. We evaluated human ovarian carcinoma clinical specimens and determined that high expression of IL-6 was associated with increased tumor vascularization. Additionally, endothelial cells derived from the ovary and mesentery expressed the IL-6 receptor (IL-6R), and their stimulation with the exogenous ligand activated downstream signaling molecules and enhanced cell migration. Dual immunohistochemical staining for CD-31 and IL-6R revealed IL-6R expression on human endothelial cells within normal ovary and ovarian carcinomas. To further investigate the possible proangiogenic function of IL-6, Gelfoam sponges containing IL-6 or bFGF were implanted into the subcutis of BALB/c mice. IL-6 containing sponges were vascularized to the same extent as bFGF containing sponges. ^ Chronic stress can adversely affect disease progression. Stimulation of ovarian carcinoma cell lines with concentrations of catecholamines achieved in individuals experiencing chronic stress resulted in a substantial increase in IL-6 production. It was determined that stress mediators regulate IL-6 expression through the β-adrenergic receptor and Src. These data illustrate one mechanism by which chronic stress may influence tumor progression. ^ To investigate whether IL-6 contributes to the angiogenesis of ovarian carcinomas, we isolated low IL-6 expressing clones from the SKOV3.ip1 cell line and transfected them with a plasmid encoding the IL-6 gene. We observed no difference in tumor weight between high and low IL-6 expressing cells. However, while low IL-6 expressing tumors were highly vascularized, high IL-6 expressing tumors appeared hypervascularized. Immunohistochemical analysis revealed that all tumors exhibited robust expression of additional proangiogenic molecules. ^ Collectively, these studies indicate that IL-6 secreted by ovarian cancer cells is a highly proangiogenic cytokine. However, IL-6 is but one of several proangiogenic molecules produced by ovarian cancer, and its inhibition may not be sufficient to inhibit angiogenesis of ovarian carcinoma. The findings presented in this dissertation provide insight into the function of IL-6 as a regulator of angiogenesis. Understanding of the role of proangiogenic molecules such as IL-6 in ovarian carcinoma may have important implications for therapy directed at the vascular component of this disease. ^

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CD-ROMs have proliferated as a distribution media for desktop machines for a large variety of multimedia applications (targeted for a single-user environment) like encyclopedias, magazines and games. With CD-ROM capacities up to 3 GB being available in the near future, they will form an integral part of Video on Demand (VoD) servers to store full-length movies and multimedia. In the first section of this paper we look at issues related to the single- user desktop environment. Since these multimedia applications are highly interactive in nature, we take a pragmatic approach, and have made a detailed study of the multimedia application behavior in terms of the I/O request patterns generated to the CD-ROM subsystem by tracing these patterns. We discuss prefetch buffer design and seek time characteristics in the context of the analysis of these traces. We also propose an adaptive main-memory hosted cache that receives caching hints from the application to reduce the latency when the user moves from one node of the hyper graph to another. In the second section we look at the use of CD-ROM in a VoD server and discuss the problem of scheduling multiple request streams and buffer management in this scenario. We adapt the C-SCAN (Circular SCAN) algorithm to suit the CD-ROM drive characteristics and prove that it is optimal in terms of buffer size management. We provide computationally inexpensive relations by which this algorithm can be implemented. We then propose an admission control algorithm which admits new request streams without disrupting the continuity of playback of the previous request streams. The algorithm also supports operations such as fast forward and replay. Finally, we discuss the problem of optimal placement of MPEG streams on CD-ROMs in the third section.

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利用微宇宙系统研究了不同浓度的Hg2+、Cd2+单一及复合处理下,苦草对这三种胁迫的响应。三种胁迫下,3d内苦草现存量增加百分比与金属离子浓度间显著负相关,其中在[Hg2+]或[Hg2++Cd2+]([Hg2+]/[Cd2+]=1)>5μmol/L时,2~3d可致死;总生产力、净生产力、呼吸强度以及叶绿素含量均随着金属离子浓度的增加而下降,同时叶绿素含量还随着胁迫时间的延长而降低,但上述四个指标在低浓度胁迫时常略有升高;可溶性蛋白含量在[Hg2+]或[Hg2++Cd2+]≤2.5μmol/L、以及[Cd2

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863计划资助(2002AA601021); 973计划(2002CB412309)资助

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采用室内培养和室内分析相结合的方法,研究了外源Cd2+进入土壤30d后,在土壤各级微团聚体中的含量富集和形态赋存情况。研究结果表明:外源水溶性镉进入土壤30d后,100%转化成了颗粒态,其中58.5%转化为了可交换态,0.98%转化成了碳酸盐结合态,1.26%转化成了铁锰氧化物结合态,7.68%转化成了有机结合态,31.5%转化成了残渣态,这基本与其中各粒级微团聚体中的赋存形态的情况一致。在土壤中赋存的镉主要分布在各级微团聚体中,在各粒级微团聚体中的含量分布顺序为<10μm微团聚体>10~50μm微团聚体>50~250μm微团聚体;外源镉向小粒级微团聚体的富集倾向明显高于向大粒级微团聚体的富集倾向,其中在<10μm微团聚体中富集系数为1.43,在50~250μm微团聚体中的富集系数只有0.60。

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Pinus sylvestris seedlings infected with either the ectomycorrhizal (ECM) fungus Paxillus involutus or Suillus variegatus were exposed to a range of Cd or Zn concentrations. This was done to investigate the relationship between the sensitivity of ECM fungi and their host plants over a wide range of concentrations. P involutus ameliorated the toxicity of Cd and Zn to P. sylvestris with respect to root length, despite significant inhibition of ECM infection levels by Cd (Cd EC50 [effective concentration which inhibits ECM infection by 50%] values were: P. involutus 3.7 μg g-1 Cd; S. variegatus 2.3 μg g-1 Cd). ECM infection by P. involutus also decreased Cd and Zn transport to the plant shoots at potentially toxic concentrations and also influenced the proportion of Zn transported to the roots and shoots, with a higher proportion retained in the roots of the seedlings. ECM infection did increase host biomass production, but this was not affected by the presence of Cd or Zn. Root and shoot biomass production by P. sylvestris, in both the presence and absence of ECM fungi, was unaffected by Cd and Zn at all concentrations tested.