62 research outputs found
Perfluorinated compounds in the Pearl River and Yangtze River of China
A total of 14 perfluorinated compounds (PFCs) were quantified in river water samples collected from tributaries of the Pearl River (Guangzhou Province, south China) and the Yangtze River (central China). Among the PFCs analyzed, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were the two compounds with the highest concentrations. PFOS concentrations ranged from 0.90 to 99 ng/1 and < 0.01-14 ng/1 in samples from the Pearl River and Yangtze River, respectively; whereas those for PFOA ranged from 0.85 to 13 ng/l and 2.0-260 ng/l. Lower concentrations were measured for perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluorooctanesulfoamide (PFOSA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorononaoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA). Concentrations of several perfluorocarboxylic acids, including perfluorododecanoic acid (PFDoDA), perfluorotetradecanoic acid (PFTeDA), perfluorohexadecanoic acid (PFHxDA) and perfluorooctadecanoic acid (PFOcDA) were lower than the limits of quantification in all the samples analyzed. The highest concentrations of most PFCs were observed in water samples from the Yangtze River near Shanghai, the major industrial and financial centre in China. In addition, sampling locations in the lower reaches of the Yangtze River with a reduced flow rate might serve as a final sink for contaminants from the upstream river runoffs. Generally, PFOS was the dominant PFC found in samples from the Pearl River, while PFOA was the predominant PFC in water from the Yangtze River. Specifically, a considerable amount of PFBS (22.9-26.1% of total PFC analyzed) was measured in water collected near Nanjing, which indicates the presence of potential sources of PFBS in this part of China. Completely different PFC composition profiles were observed for samples from the Pearl River and the Yangtze River. This indicates the presence of dissimilar sources in these two regions. (c) 2007 Elsevier Ltd. All rights reserved.A total of 14 perfluorinated compounds (PFCs) were quantified in river water samples collected from tributaries of the Pearl River (Guangzhou Province, south China) and the Yangtze River (central China). Among the PFCs analyzed, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were the two compounds with the highest concentrations. PFOS concentrations ranged from 0.90 to 99 ng/1 and < 0.01-14 ng/1 in samples from the Pearl River and Yangtze River, respectively; whereas those for PFOA ranged from 0.85 to 13 ng/l and 2.0-260 ng/l. Lower concentrations were measured for perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluorooctanesulfoamide (PFOSA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorononaoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA). Concentrations of several perfluorocarboxylic acids, including perfluorododecanoic acid (PFDoDA), perfluorotetradecanoic acid (PFTeDA), perfluorohexadecanoic acid (PFHxDA) and perfluorooctadecanoic acid (PFOcDA) were lower than the limits of quantification in all the samples analyzed. The highest concentrations of most PFCs were observed in water samples from the Yangtze River near Shanghai, the major industrial and financial centre in China. In addition, sampling locations in the lower reaches of the Yangtze River with a reduced flow rate might serve as a final sink for contaminants from the upstream river runoffs. Generally, PFOS was the dominant PFC found in samples from the Pearl River, while PFOA was the predominant PFC in water from the Yangtze River. Specifically, a considerable amount of PFBS (22.9-26.1% of total PFC analyzed) was measured in water collected near Nanjing, which indicates the presence of potential sources of PFBS in this part of China. Completely different PFC composition profiles were observed for samples from the Pearl River and the Yangtze River. This indicates the presence of dissimilar sources in these two regions. (c) 2007 Elsevier Ltd. All rights reserved
Different significance between intratumoral and peritumoral lymphatic vessel density in gastric cancer: a retrospective study of 123 cases
<p>Abstract</p> <p>Background</p> <p>Patients with gastric cancer in China have worse outcome and poorer prognosis. Tumor-induced lymphangiogenesis plays a crucial role in metastasis and tumor progression. The intratumoral and peritumoral lymphatics were supposed to have different biological effects. Three major growth factors, vascular endothelial growth factor- (VEGF)-A, VEGF-C and VEGF-D, are involved in the activation process via their receptors (VEGFRs). The purpose of current study is to investigate the significant difference between intratumoral and peritumoral lymphatic vessel density (LVD) in gastric cancer and their correlations with lymphangiogenetic growth factors.</p> <p>Methods</p> <p>Intratumoral LVD (I-LVD) and peritumoral LVD (P-LVD) of 123 patients with primary gastric cancer were assessed after staining with D2-40, and confirmed by double staining with D2-40/CD34. Proliferative activity of lymphatics endothelium was evaluated by double staining with D2-40/Ki-67. The associations were analyzed between I-LVD/P-LVD and the expression level of VEGF-A, VEGF-C, VEGF-D and the receptor VEGFR-3, which was measured by immunohistochemistry (IHC). The correlations of I-LVD and P-LVD with patient prognosis were also valued.</p> <p>Results</p> <p>(1) The peritumoral lymphatics (PTLs) were relatively enlarged with dilated lumen compared with the intratumoral lymphatics (ITLs). Increased P-LVD was significantly higher than I-LVD (<it>P </it>< 0.05). (2) P-LVD was found significantly associated with lymph node metastasis (LNM) (<it>P </it>< 0.001), lymphatic vessel invasion (LVI) (<it>P </it>< 0.001), VEGF-C (<it>P </it>= 0.003), VEGF-D expression level (<it>P </it>= 0.005) and VEGFR-3 expression level (<it>P </it>< 0.001) in peritumoral tissues, despite no significant association was found between above variants with I-LVD. However, increased I-LVD was demonstrated to be associated with decreased tumor volume (<it>P </it>< 0.001). Neither I-LVD nor P-LVD was correlated with VEGF-A expression (<it>P </it>> 0.05). (3) Proliferative activity of lymphatics endothelium was observed in PTLs, in spite of ITLs. (4) Increased P-LVD, but not I-LVD, was indicated to be an independent risk factor for lymph node metastasis by multivariate logistic regression analysis, and was related to worse disease-free survival and overall survival.</p> <p>Conclusions</p> <p>PTLs play roles in gastric cancer progression. Increased P-LVD, but not I-LVD, was significantly associated with VEGF-C/-D/VEGFR-3 system, and could be an independent risk factor for lymph node metastasis and a prognostic factor in gastric cancer.</p
Marrow angiogenesis-associated factors as prognostic biomarkers in patients with acute myelogenous leukaemia
Bone marrow (BM) neoangiogenesis plays an important role in acute myelogenous leukaemia (AML), and depends on the interplay of members of the vascular endothelial growth factor (VEGF) and angiopoietin (Ang) families. We determined the marrow levels of seven molecules associated with angiogenesis in 52 AML patients before chemotherapy and 20 healthy controls: VEGF-A, VEGF/PlGF, VEGF-C, VEGF-D, Ang-1, Ang-2, and Tie-2. All the molecules were quantified using enzyme-linked immunosorbent assay (ELISA). Comparing to normal controls, the marrow levels of VEGF/PlGF, Ang-2, and Tie-2 were significantly higher, and those of VEGF-C and Ang-1 were significantly lower in the AML patients (P<0.001). A total of 31 patients were further subjected to survival analysis. Patients with lower Tie-2 (<26 ng ml−1) and Ang-2 levels (<4500 pg ml−1) displayed a survival advantage (P=0.037 and 0.042, respectively), same as patients with higher VEGF/PlGF (⩾1 pg ml−1) and VEGF-D levels (⩾350 pg ml−1) (P=0.020 and 0.016, respectively). An angio-index ((Ang-2 × Tie-2)/(VEGF/PlGF × VEGF-D)) was established and multivariate Cox regression analysis revealed that patients with higher angio-index values (⩾50) displayed poor prognosis (hazard ratio 5.91, 95% confidence interval 1.99–17.56; P=0.001). The angio-index is closely associated with the clinical outcome of AML patients and may be valuable in disease prognosis
Role of the VEGF ligand to receptor ratio in the progression of mismatch repair-proficient colorectal cancer
The VEGF family of ligands and receptors are intimately involved in tumor angiogenesis, lymphangiogenesis and metastasis. The evaluation of VEGF ligand/receptor ratios may provide a more profound understanding of the involvement of these proteins in colorectal tumour progression. The aim of this study was to elucidate the role of the VEGF ligand/receptor ratios on tumour progression and metastasis in patients with mismatch repair-proficient colorectal cancer
Recombinant Human Endostatin Endostar Inhibits Tumor Growth and Metastasis in a Mouse Xenograft Model of Colon Cancer
To investigate the effects of recombinant human endostatin Endostar on metastasis and angiogenesis and lymphangiogenesis of colorectal cancer cells in a mouse xenograft model. Colon cancer cells SW620 were injected subcutaneously into the left hind flank of nude mice to establish mouse xenograft models. The mice were treated with normal saline or Endostar subcutaneously every other day. The growth and lymph node metastasis of tumor cells, angiogenesis and lymphangiogenesis in tumor tissue were detected. Apoptosis and cell cycle distribution were studied by flow cytometry. The expression of VEGF-A, -C, or -D in SW620 cells was determined by immunoblotting assays. Endostar inhibited tumor growth and the rate of lymph node metastasis (P < 0.01). The density of blood vessels in or around the tumor area was 12.27 ± 1.21 and 22.25 ± 2.69 per field in Endostar-treated mice and controls (P < 0.05), respectively. Endostar also decreased the density of lymphatic vessels in tumor tissues (7.84 ± 0.81 vs. 13.83 ± 1.08, P < 0.05). Endostar suppresses angiogenesis and lymphangiogenesis in the lymph nodes with metastases, simultaneously. The expression of VEGF-A, -C and -D in SW620 cells treated with Endostar was substantially lower than that of controls. Endostar inhibited growth and lymph node metastasis of colon cancer cells by inhibiting angiogenesis and lymphangiogenesis in a mouse xenograft model of colon cancer
Microvessel density and VEGF expression are prognostic factors in colorectal cancer. Meta-analysis of the literature
We performed a meta-analysis of all published studies relating intratumoural microvessel density (MVD) (45 studies) or vascular endothelial growth factor (VEGF) expression (27 studies), both reflecting angiogenesis, to relapse free (RFS) and overall survival (OS) in colorectal cancer (CRC). For each study, MVD impact was measured by risk ratio between the two survival distributions with median MVD as cutoff. Eleven studies did not mention survival data or fit inclusion criteria, six were multiple publications of same series, leaving 32 independent studies for MVD (3496 patients) and 18 for VEGF (2050 patients). Microvessel density was assessed by immunohistochemistry, using antibodies against factor VIII (16 studies), CD31 (10 studies) or CD34 (seven studies). Vascular endothelial growth factor expression was mostly assessed by immunohistochemistry. Statistics were performed for MVD in 22 studies (the others lacking survival statistics) including nine studies (n=957) for RFS and 18 for OS (n=2383) and for VEGF in 17 studies, including nine studies for RFS (n=1064) and 10 for OS (n=1301). High MVD significantly predicted poor RFS (RR=2.32 95% CI: 1.39–3.90; P<0.001) and OS (RR=1.44; 95% CI: 1.08–1.92; P=0.01). Using CD31 or CD34, MVD was inversely related to survival, whereas it was not using factor VIII. Vascular endothelial growth factor expression significantly predicted poor RFS (RR=2.84; 95% CI: 1.95–4.16) and OS (RR=1.65; 95% CI: 1.27–2.14). To strengthen our findings, future prospective studies should explore the relation between MVD or VEGF expression and survival or response to therapy (e.g. antiangiogenic therapy). Assessment of these angiogenic markers should be better standardised in future studies
Staphylococcus aureus α-Hemolysin Activates the NLRP3-Inflammasome in Human and Mouse Monocytic Cells
Community Acquired Methicillin Resistant Staphylococcus aureus (CA-MRSA) causes severe necrotizing infections of the skin, soft tissues, and lungs. Staphylococcal α-hemolysin is an essential virulence factor in mouse models of CA-MRSA necrotizing pneumonia. S. aureus α-hemolysin has long been known to induce inflammatory signaling and cell death in host organisms, however the mechanism underlying these signaling events were not well understood. Using highly purified recombinant α-hemolysin, we now demonstrate that α-hemolysin activates the Nucleotide-binding domain and leucine-rich repeat containing gene family, pyrin domain containing 3 protein (NLRP3)-inflammasome, a host inflammatory signaling complex involved in responses to pathogens and endogenous danger signals. Non-cytolytic mutant α-hemolysin molecules fail to elicit NLRP3-inflammasome signaling, demonstrating that the responses are not due to non-specific activation of this innate immune signaling system by bacterially derived proteins. In monocyte-derived cells from humans and mice, inflammasome assembly in response to α-hemolysin results in activation of the cysteine proteinase, caspase-1. We also show that inflammasome activation by α-hemolysin works in conjunction with signaling by other CA-MRSA-derived Pathogen Associated Molecular Patterns (PAMPs) to induce secretion of pro-inflammatory cytokines IL-1β and IL-18. Additionally, α-hemolysin induces cell death in these cells through an NLRP3-dependent program of cellular necrosis, resulting in the release of endogenous pro-inflammatory molecules, like the chromatin-associated protein, High-mobility group box 1 (HMGB1). These studies link the activity of a major S. aureus virulence factor to a specific host signaling pathway. The cellular events linked to inflammasome activity have clear relevance to the disease processes associated with CA-MRSA including tissue necrosis and inflammation
COX-2-mediated stimulation of the lymphangiogenic factor VEGF-C in human breast cancer
Increased expression of COX-2 or VEGF-C has been correlated with progressive disease in certain cancers. Present study utilized several human breast cancer cell lines (MCF-7, T-47D, Hs578T and MDA-MB-231, varying in COX-2 expression) as well as 10 human breast cancer specimens to examine the roles of COX-2 and prostaglandin E (EP) receptors in VEGF-C expression or secretion, and the relationship of COX-2 or VEGF-C expression to lymphangiogenesis. We found a strong correlation between COX-2 mRNA expression and VEGF-C expression or secretion levels in breast cancer cell lines and VEGF-C expression in breast cancer tissues. Expression of LYVE-1, a selective marker for lymphatic endothelium, was also positively correlated with COX-2 or VEGF-C expression in breast cancer tissues. Inhibition of VEGF-C expression and secretion in the presence of COX-1/2 or COX-2 inhibitors or following downregulation of COX-2 with COX-2 siRNA established a stimulatory role COX-2 in VEGF-C synthesis by breast cancer cells. EP1 as well as EP4 receptor antagonists inhibited VEGF-C production indicating the roles of EP1 and EP4 in VEGF-C upregulation by endogenous PGE2. Finally, VEGF-C secretion by MDA-MB-231 cells was inhibited in the presence of kinase inhibitors for Her-2/neu, Src and p38 MAPK, indicating a requirement of these kinases for VEGF-C synthesis. These results, for the first time, demonstrate a regulatory role of COX-2 in VEGF-C synthesis (and thereby lymphangiogenesis) in human breast cancer, which is mediated at least in part by EP1/EP4 receptors
Double-positive expression of high-mobility group box 1 and vascular endothelial growth factor C indicates a poorer prognosis in gastric cancer patients
Prognostic significance of vascular endothelial cell growth factors -A, -C and -D in breast cancer and their relationship with angio- and lymphangiogenesis
Vascular endothelial cell growth factors (VEGF)-A, -C and -D have potent angio and lymphangiogenic functions in experimental models, although their role in the progression of human breast cancer is unclear. The aims of the current study were to examine the relationship between the expression of the aforementioned growth factors with the angio and lymphangiogenic characteristics of breast cancer, and to assess their suitability as potential prognostic factors. Paraffin-embedded sections of 177 primary invasive breast cancer, with complete clinical follow-up information for 10 years, were stained for VEGF-A, -C, -D, podoplanin and CD34 using standard immunohistochemical approaches. The expression of the growth factors was correlated with clinicopathological criteria and patients' survival. Lymph vessel density (LVD) and microvessel density (MVD) were assessed and correlated with expression of the growth factors. Vascular endothelial cell growth factor-A, -C and -D were highly expressed in 40, 37 and 42% of specimens, respectively. High expression of VEGF-A and - C, but not of -D, was associated with a higher LVD (P=0.013 and P=0.014, respectively), a higher MVD (P<0.001 and P=0.002, respectively), the presence of lymph node metastasis (P<0.001 and P<0.001, respectively), distant metastasis (P=0.010 and P=0.008, respectively) and a shorter Overall Survival (P=0.029 and 0.028, respectively). In conclusion, breast cancers that express high levels of VEGF-A and -C are characterised by a poor prognosis, likely through the induction of angio and lymphangiogenesis. Examination of expression of VEGF-A and -C in breast cancer may be beneficial in the identification of a subset of tumours that have a higher probability of recurrence and metastatic spread
- …
