Tissue-engineered dermo-epidermal skin grafts prevascularized with adipose-derived cells

The major problem in skin grafting is that tissue-engineered skin grafts after their transplantation are initially entirely dependent on diffusion. Since this process is slow and inefficient, nutrients, growth factors, and oxygen will insufficiently be supplied and the regenerating graft will undergo a physiological crisis, resulting in scar-like dermal structures and shrinkage. The tissue-engineering of a vascular network in human dermo-epidermal skin substitutes (DESS) is a promising approach to overcome this limitation. Here we report, for the first time, on the use of the adipose stromal vascular fraction (SVF)-derived endothelial cell population to tissue-engineer DESS containing a highly efficient capillary plexus. To develop vascular networks in vitro, we employed optimized 3D fibrin or collagen type I hydrogel systems. Upon transplantation onto immune-deficient rats, these pre-formed vascular networks anastomosed to the recipient's vasculature within only four days. As a consequence, the neo-epidermis efficiently established tissue homeostasis, the dermis underwent almost no contraction, and showed sustained epidermal coverage in vivo. Overall, the here described rapid and efficient perfusion of SVF-based skin grafts opens new perspectives for the treatment of hitherto unmet clinical needs in burn/plastic surgery and dermatology.     

Long-Term Follow-Up of R-CHOP With Bevacizumab as Initial Therapy for Mantle Cell Lymphoma: Clinical and Correlative Results

BackgroundEmerging evidence indicates that MCL has increased angiogenesis within the tumor microenvironment. We initiated a phase II trial to determine if the addition of bevacizumab to the standard R-CHOP regimen could enhance antitumor effects in patients with previously untreated MCL.Patients and MethodsEleven patients with previously untreated MCL received bevacizumab at 15 mg/kg on day 1, and standard CHOP-21 (CHOP given every 21 days per cycle) with rituximab (375 mg/m² per cycle) on day 3 of each cycle for a total of 6 cycles. Planned study end points included safety and efficacy assessment, and exploratory analysis of angiogenic profiles. The study was suspended in August of 2010 based on safety findings in DLBCL (diffuse large B-cell lymphoma) of increased cardiovascular events with the regimen.ResultsBeyond the standard R-CHOP safety profile, Grade 3 left ventricular dysfunction developed in 2 patients (18%), Grade 1/2 hypertension, proteinuria, and bleeding each developed in 1 patient (9%). The overall response rate was 82% with 36% complete response (CR)/complete response unconfirmed (CRu). The median progression-free survival (n = 11) was 18 months (95% confidence interval, 3-not reached), and 3-year overall survival rate was 82%. Correlative studies showed increased vascular endothelial growth factor receptor 1 expression in tumor cells at baseline, and elevated levels of plasma vascular endothelial growth factor (VEGF) throughout treatment.ConclusionThe addition of bevacizumab to the standard R-CHOP regimen did not appear to significantly improve efficacy beyond that observed from previous studies using R-CHOP alone. Therapeutic strategies that provide sustained inhibition on VEGF-related and VEGF-independent targets within the tumor microenvironment might further improve antiangiogenic effects and warrant further exploration in MCL.     

Nodal蛋白在肾细胞癌组织中的表达及意义

目的研究胚胎成形素Nodal蛋白在肾细胞癌组织中的表达情况，并探讨其临床意义．方法采用免疫组织化学、Westernblot及Realtime PCR方法分别检测25例肾细胞癌组织及16例正常肾组织中NodalmRNA、蛋白的表迭，并检测微血管密度（MVD）指教，分析比较不同临床分期、组织学分级肾细胞癌组织中Nodal的表达情况及其与MVD之间的相关关系。结果肾细胞癌高表迭Nodal mRNA基因及蛋白，且随着临床分期的升高及组织学分级的恶化，NodalmRNA基因及蛋白表达水平不断上升；不同的临床分期及组织学分级中，Nodal蛋白的表达与MVD的变化趋势之间均存在明显的正相关关系。结论肾细胞癌高表达Nodal基因及蛋白，Nodal可能通过促进新生肿瘤血管生成促进肾癌的发展。     

Changes of NK Cells in Preeclampsia

The regulation of uterine and circulating peripheral blood natural killer (NK) cells has been associated with reproductive immunology such as recurrent pregnancy losses, implantation failures, or preeclampsia. Preeclampsia is a hypertensive disorder of pregnancy characterized by increased blood pressure accompanied by proteinuria and is a major cause of maternal and fetal mortality. Natural cytotoxicity receptors (NCRs) are unique markers, which regulate NK cell cytotoxicity and cytokine production. The relation of NCRs to reproduction is not fully characterized yet. The different profile of NCRs expression may suggest presence of abnormal regulation of NK cell in women with reproductive failures. Pregnant women with preeclampsia carry immunological abnormalities of NCRs on peripheral blood NK cells during pregnancy. The lower expression of NKp46⁺ NK cells in women with preeclampsia may account for the higher production of NK1 cytokine that is known as NK1 shift in pregnant women with preeclampsia. Evaluation of NKp46 on peripheral blood NK cells may be applicable to find the onset of preeclampsia. In this review, various expressions of NK cell surface markers including NCRs on NK cells, NK cell cytotoxicity, and production of cytokines and angiogenic factors by NK cells were reviewed in relation to preeclampsia.     

Anti-angiogenic therapy in pediatric brain tumors: An effective strategy?

Brain tumors are still the leading cause of cancer morbidity and mortality among children, despite different therapeutic options including neurosurgery, chemotherapy and radiation. As angiogenesis is highly crucial in brain tumor growth and progression, numerous clinical trials evaluating diverse anti-angiogenic agents have been described. In the present review, we aimed to answer the question if anti-angiogenic therapy is an effective strategy in the treatment of children with brain tumors. Although some encouraging results have been published of anti-angiogenic therapy targeting vascular endothelial growth factor (VEGF)/VEGF receptor signaling or epidermal growth factor receptor (EGFR), still more insight is warranted to be highly conclusive about the efficacy of anti-angiogenic therapy with currently potential upcoming anti-angiogenic agents in pediatric brain tumors. However, given the need for new therapeutic strategies, multi targeted therapy with anti-angiogenic agents anticipating on possible tumor escape mechanisms could be effective in the future treatment of pediatric brain tumors.     

Systemic effects of angiogenesis inhibition alter pharmacokinetics and intratumoral delivery of nab-paclitaxel

Angiogenesis is critical to the growth of tumors. Vascularization-targeting agents, with or without cytotoxic drugs, are widely used for the treatment of several solid tumors including esophagogastric adenocarcinoma. However, little is known about the systemic effects of anti-angiogenic therapies and how this affects the pharmacokinetics and intratumoral delivery of cytotoxic agents. In this study, patient-derived xenograft mouse models of esophageal adenocarcinoma were used to identify the effects of DC101, a murine vascular endothelial growth factor receptor 2 (VEGFR2) inhibitor, on the pharmacokinetics and the intratumoral uptake of nab-paclitaxel (NPTX). We showed that DC101 had large systemic effects resulting in decreased vasculature of intraperitoneally located organs. As a consequence, after intraperitoneal administration of NPTX, plasma uptake (5.029?±?4.35 vs. 25.85?±?2.27?µM) and intratumoral delivery (5.48?±?5.32 vs. 38.49?±?2.805?pmol/mg) of NPTX were greatly impaired in DC101-treated animals compared to control animals. Additionally, routes of NPTX elimination were altered upon angiogenesis inhibition; unchanged renal clearance and intraperitoneal accumulation of NPTX were observed, but NPTX levels were significantly lower in the liver. Histological examination of the intestine revealed a reduced thickness of the intestinal wall following DC101 therapy and suggested seepage of intraperitoneally injected NTPX through the intestinal wall to explain its reduced uptake in liver, plasma, and tumor tissue. These data explain several adverse effects observed in the clinic when using anti-angiogenic therapies and also imply that the combined use of anti-angiogenesis and cytotoxic agents in both preclinical and clinical setting is still suboptimal.     

Perfusion and vascular permeability: Basic concepts and measurement in DCE-CT and DCE-MRI

The microvascular network formed by the capillaries supplies the tissues and permits their function. It provides a considerable surface area for exchanges between blood and tissues. All pathological conditions cause changes in the microcirculation. These changes can be used as imaging biomarkers for the diagnosis of lesions and optimisation of treatment. Among the many imaging techniques developed to study the microcirculation, the analysis of the tissue kinetics of intravenously injected contrast agents is the most widely used, either as positive enhancement for CT, T1-weighted MRI and ultrasound – dynamic contrast-enhanced-imaging (DCE-imaging) – or negative enhancement in T2*-weighted brain MRI – dynamic susceptibility contrast-MRI (DSC-MRI) –. Acquisition involves an injection of contrast agent during the acquisition of a dynamic series of images on a zone of interest. These kinetics may be analyzed visually, to define qualitative criteria, or with software using mathematical modelling, to extract quantitative physiological parameters. The results depend on the acquisition conditions (type of imaging device, imaging mode, frequency and total duration of acquisition), the type of contrast agent, the data pre-processing (motion correction, conversion of the signal into concentration) and the data analysis method. Because of these multiple choices it is necessary to understand the physiological processes involved and understand the advantages and limits of each strategy.     

VEGF-PLGA controlled-release microspheres enhanced angiogenesis in encephalomyosynangiosis-based chronic cerebral hypoperfusion

Treatments enhancing angiogenesis for chronic cerebral hypoperfusion (CCH) are still in the research stage. Although encephalomyosynangiosis (EMS) is a common indirect anastomosis for the treatment of CCH, the effectiveness to promote angiogenesis is not satisfactory. Vascular endothelial growth factors (VEGF) is a cytokine found to specifically act directly on vascular endothelial cells, promote neovascularization, and enhance capillary permeability. However, the short half life and unstable property of VEGF underlies the need to explore available delivery system. In this study, poly (lactide-co-glycolide) (PLGA) was used to prepare VEGF controlled-release microspheres. In vitro and in vivo analysis of release kinetics showed that the microspheres could release VEGF continuously within 30 days. Then, modified chronic cerebral hypoperfusion rat model was established by ligation of bilateral internal carotid artery and one vertebral artery. At 14 days after ischemia, the EMS and the VEGF microspheres injection were performed. At 30 days after the injection, the result of Morris water maze displayed that combinating VEGF microspheres and EMS significantly ameliorated cognitive deficit after ischemia. We observed that combinating VEGF microspheres and EMS could further significantly increase cerebral blood flow. We speculated that this enhancement of cerebral blood flow was attributed to more angiogenesis induced by combination of VEGF microspheres and EMS, which verified by more collateral circulation with cerebral angiography and higher expression of CD31 or α-SMA. Our study demonstrated that combinating VEGF-PLGA controlled-release microspheres could significantly promote angiogenesis in EMS-based CCH rats model, providing new ideas for clinical treatment of CCH.