This paper presents results concerning the influence of membrane properties on effective recirculation of chromium(III) from tannery wastewater by nanofiltration process. DK, HL, DL “thin film” ...membranes and asymmetric CK membrane were tested for theirs permeability and selectivity on model chromium solution contained 2
gCr
3+/dm
3, 10
gCl
−/dm
3 and 10
gSO
4
2−/dm
3. Presented results allowed to conclude that both the high permeability and selectivity of NF membranes used for chromium recirculation from low pH, concentrate salt mixture solution are dependent on the membrane surface charge phenomenon. The retaining of the high permeate flux of chromium tannery wastewater at pH below 4, required the use of membranes with their IP as low as possible to assured the negative NF membrane surface charge and low chloride ions retention equal to 7–11%. As a consequence the polarization effect was reduced and the increase of permeate flux was observed. The use of such membranes guarantees obtaining of both a high permeate flux and a concentrated solution of chromium(III) as retentate which is suitable for recirculation. Due to the fouling and aggressive conditions characterized the tanning wastewater the polyamide/polysulfone membranes are suggested. The cellulose acetate membranes do not ensure satisfied results during treatment of tannery wastewater.
► Recirculation of Cr(III) from model tannery solution by NF was studied. ► Effect of properties of NF membranes on process was analyzed. ► High permeability of membranes is obtained for negative membrane charge. ► Low pH and high salt concentration in tannery solution modified membrane charge. ► Membranes with low IP allows obtaining a concentrate of Cr(III) under TMP of 14
bar.
This paper presents the results of analyses of the chromium(III) transport process from mixtures of Cr(III)/Cr(VI) ions using supported liquid membranes (SLM), in which dinonylnaphthalene sulfonic ...acid (DNNSA) and di(2-ethylhexyl) phosphoric acid (D2EHPA) were used as carriers. In both cases the membrane worked as a selective barrier for Cr(VI) ions. The increase in both the time of Cr(VI) ions-carrier interaction and the Cr(VI) concentration in the feed phase negatively influenced the Cr(III) separation. The polarizing layer consisting of Cr(VI) ions prevents the access of Cr(III) ions to the inter phase surface and leads to the deactivation of the carrier, which is the result of the strong oxidation properties of Cr(VI) ions. These factors meant that, in the case of the membrane with DNNSA, the membrane could not be used for the effective separation of Cr(III) from the Cr(III)/Cr(VI) mixture. On the other hand, the membrane with D2EHPA can be used for fast and efficient transport of Cr(III) ions, but only for strictly defined process parameters, i.e. where the level of chromium(VI) concentration is below 10(-3)M and with intensive feed phase mixing.
Unprovoked venous thromboembolism (VTE) may be the first manifestation of an underlying cancer. We aimed to assess the period prevalence of occult cancer detection stratified by VTE location (deep ...vein thrombosis DVT, pulmonary embolism PE or both) and the anatomical relationship between occult cancer and VTE.
Post-hoc analysis of a systematic review and individual patient data meta-analysis of adults with unprovoked VTE with at least 12 months of follow-up. Cancer types were grouped according to thoracic, abdomino-pelvic, or other locations.
A total of 2300 patients were eligible including 1218 with DVT only (53%), 719 with PE only (31%), and 363 with both PE and DVT (16%). The pooled 12-month period prevalence of cancer in DVT only, PE only, and DVT + PE was 5.6% (95% CI, 4.4 to 7.2), 4.3% (95% CI, 2.7 to 6.9), and 5.6% (95% CI, 1.7 to 15.5), respectively. Most occult cancers were located in the abdomen (68.4%). The proportion of patients with an abdomino-pelvic cancer was not different in patients with DVT + PE (81%; 95% CI, 54 to 96) than in those with DVT (68%; 95% CI, 57 to 78) or PE alone (65%; 95% CI, 48 to 79).
The 12-month prevalence of occult cancer was similar in patients with DVT only, PE only, or both. Most cancers were located in the abdomen, and there was no relationship between VTE type and cancer location.
•The relationship between sites of VTE and occult cancer is unclear.•The 12-month prevalence of occult cancer was similar in DVT only, PE only, or both.•There were no relationship between unprovoked VTE and occult cancer locations.•Two thirds of cancers diagnosed after unprovoked VTE were located in the abdomen.
Abstract Objectives Previous studies have demonstrated elevation of systemic levels of inflammatory cytokines after treadmill exercise in patients with intermittent claudication (IC), but it is ...unknown if growth factor expression also is stimulated. The aim of this study was to assess whether physical exercise-induced ischemia elicits an inflammatory response and increase in local and systemic vascular growth factor expression in patients with IC. Methods Nineteen patients with IC had plasma concentrations of inflammatory markers (IL-6, TNF-alpha, hs-CRP) and vascular growth factors (VEGF and FGF-2) measured before and at four time points after a treadmill exercise test. In 10 patients a gastrocnemius muscle biopsy was obtained to measure VEGF and FGF-2 mRNA. Plasma concentrations of vWF were also measured. Five patients who underwent the treadmill test without experiencing calf pain were enrolled as controls. Results Plasma concentrations of IL-6 increased after exercise ( p = 0.004), while TNF-alpha and hs-CRP were unchanged ( p = 0.191 and p = 0.709, respectively). Plasma concentrations of VEGF were similar ( p = 0.151) at the different time points after exercise but FGF-2 levels decreased ( p = 0.013). In biopsies after treadmill testing VEGF-A mRNA was increased ( p = 0.043), but no change was observed for FGF-2 ( p = 0.456). Conclusion Exercise in IC triggers an inflammatory response as exemplified by elevated concentrations of IL-6. After exercise-induced pain, VEGF mRNA in calf muscle is increased. Therefore, it is plausible that angiogenesis is stimulated by exercise in IC.
Vascular progenitor cells contribute to repair of injured vasculature. In this study, we aimed to investigate the role of bone marrow–derived cells in the intimal formation after arterial injury.
...Balloon injury of the femoral artery of wild-type mice was followed by local delivery of bone marrow–derived cells from GFP transgenic mice. The arteries were collected 1, 4, 7, and 14 days after injury and studied for morphology, localization, and phenotypes of delivered cells. Bone marrow–derived cells were present in the intima only at the early stages of arterial injury and expressed endothelial progenitor cell markers (CD31, CD34, and VEGFR-2). In the areas where intima was thicker, bone marrow–derived cells differentiated to intimal smooth muscle cells but they did not fuse with intimal cells. Delivery of CD34+ cells contributed to a 1.5-fold inhibition of intimal hyperplasia.
Bone marrow–derived endothelial cells differentiated but did not fuse with vascular smooth muscle cells at the early stages of intimal formation and contributed to intimal hyperplasia.
The functional impact of amyloid peptides (Aβs) on the vascular system is less understood despite these pathologic peptides are substantially deposited in the brain vasculature of Alzheimer's ...patients. Here we show substantial accumulation of Aβs 40 and 42 in the brain arterioles of Alzheimer's patients and of transgenic Alzheimer's mice. Purified Aβs 1-40 and 1-42 exhibited vascular regression activity in the in vivo animal models and vessel density was reversely correlated with numbers and sizes of amyloid plaques in human patients. A significant high number of vascular cells underwent cellular apoptosis in the brain vasculature of Alzheimer's patients. VEGF significantly prevented Aβ-induced endothelial apoptosis in vitro. Neuronal expression of VEGF in transgenic mice restored memory behavior of Alzheimer's. These findings provide conceptual implication of improvement of vascular functions as a novel therapeutic approach for the treatment of Alzheimer's disease.
Vascular pericytes, an important cellular component in the tumor microenvironment, are often associated with tumor vasculatures, and their functions in cancer invasion and metastasis are poorly ...understood. Here we show that PDGF-BB induces pericyte–fibroblast transition (PFT), which significantly contributes to tumor invasion and metastasis. Gain- and loss-of-function experiments demonstrate that PDGF-BB-PDGFRβ signaling promotes PFT both in vitro and in in vivo tumors. Genome-wide expression analysis indicates that PDGF-BB–activated pericytes acquire mesenchymal progenitor features. Pharmacological inhibition and genetic deletion of PDGFRβ ablate the PDGF-BB–induced PFT. Genetic tracing of pericytes with two independent mouse strains, TN-AP-CreERT2:R26R-tdTomato and NG2-CreERT2:R26R-tdTomato, shows that PFT cells gain stromal fibroblast and myofibroblast markers in tumors. Importantly, coimplantation of PFT cells with less-invasive tumor cells in mice markedly promotes tumor dissemination and invasion, leading to an increased number of circulating tumor cells and metastasis. Our findings reveal a mechanism of vascular pericytes in PDGF-BB–promoted cancer invasion and metastasis by inducing PFT, and thus targeting PFT may offer a new treatment option of cancer metastasis.
CCAAT-enhancer binding protein β (C/EBPβ) is a transcription factor that has a critical role in mammary gland development and breast cancer progression. Loss of C/EBPβ increases metastatic ...dissemination of mouse mammary tumor cells. However, the mechanism by which C/EBPβ expression affects metastasis formation remains unknown. This study aims at determining the relationship between C/EBPβ and survival of breast cancer patients, and elucidating C/EBPβ's link with metastasis formation. C/EBPβ expression was evaluated in 137 cases of human breast cancer, and the correlation with overall survival was estimated by Kaplan-Meier analysis. Additionally, the mouse 4T1 tumor model was used for in vivo studies. Decreased C/EBPβ expression was found to be associated with shorter overall survival of breast cancer patients. In the murine 4T1 model, loss of C/EBPβ affects tumor growth, morphology and promotes metastatic spread to the lungs. Immunohistochemical analyses showed that C/EBPβ inhibition leads to increased major histocompatibility complex II (MHCII) expression, followed by the accumulation of CD45-, CD3- and CD4-positive (CD4+) lymphocytes in the tumors. Inflammation involvement in C/EBPβ-mediated metastasis formation was confirmed by DNA microarray and by experiments on CD4+ cell-deprived nude mice. Additionally, anti-CD3 and anti-CD4 treatments of C/EBPβ-silenced tumor-bearing mice resulted in reverting the C/EBPβ effect on tumor growth and metastasis. Altogether, C/EBPβ is a predictor of overall survival in breast cancer patients, and affects tumor growth, morphology and lung metastasis formation in murine 4T1 model. The mechanism of metastasis formation involves immunologic response depending on C/EBPβ-mediated activation of MHCII and accumulation of CD4+ lymphocytes in the tumor.
•BDNF loss in the CNS may be contribute to depressive-like symptoms.•Congenital BBB dysfunction correlates with a depressive-like phenotype.•mTBI-induced depressive-like behaviour related to BDNF ...loss depends on BBB function.•CMS produces depressive-like behaviour in HA mice independently of BDNF deficiency.•CMS does not trigger depressive-like behaviour in LA mice with an intact BBB.
Brain-derived neurotrophic factor (BDNF) plays an important role in processes associated with neuroplasticity and neuroprotection. Evidence suggests that decreased BDNF levels in the central nervous system (CNS) represent a mechanism underlying the development of mood disorders. We hypothesize that both congenital and traumatic brain injury (mTBI)-induced blood–brain barrier (BBB) breakdown are responsible for brain BDNF depletion that contributes to the development of depressive-like symptoms. We employed a mouse model of innate differences in BBB integrity with high (HA) and low (LA) permeability. Depressive-like behaviours were determined under chronic mild stress (CMS) conditions or following mTBI using the tail suspension test (TST). Microvascular leakage of the BBB was evaluated using the Evans Blue Dye (EBD) extravasation method. BDNF concentrations in the brain and plasma were measured using the ELISA. Control HA mice with congenitally high BBB permeability showed exacerbated depressive-like behaviours compared with LA mice. In LA mice, with normal BBB function, mTBI, but not CMS, facilitated depressive-like behaviours, which correlated with enhanced BDNF efflux from the brain. In addition, mTBI triggered upregulation of the Bdnf gene in LA mice to compensate for BDNF loss. No alterations in BDNF levels were observed in mTBI and CMS-exposed HA mice. Moreover, CMS did not induce BBB damage or affect depressive-like behaviours in HA mice despite downregulating Bdnf gene expression. To conclude, BDNF efflux through the mTBI-disrupted BBB is strongly linked to the development of depressive-like behaviours, while the depressive phenotype in mice with congenital BBB dysfunction is independent of BDNF leakage.
High cytomegalovirus (CMV) IgG levels have been identified as a risk factor for arteriovenous fistula (AVF) failure. None of the 68 patents in our study were CMV IgM positive, although 96% were CMV ...IgG positive. CMV antigens were detected in the radial artery or cephalic vein of 46% of patients who received an AVF. The presence of CMV antigens or high serum CMV IgG levels had no prognostic value for AVF failure.
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