521 research outputs found
ENDIS-RISKS: endocrine disruption in the Scheldt estuary - a field study
ENDIS-RISKS, a multidisciplinary research project with five institutes, evaluates the distribution, exposure and effects of endocrine disruptors in the Scheldt Estuary. This estuary is known to be one of the most polluted estuaries in the world. Untreated domestic wastewater and effluents of the industrial areas of Ghent and Antwerp are to a large extent responsible for this pollution. During an intensive field study of four years, eight sampling campaigns were executed on seven sampling points along the Scheldt Estuary. A detailed analysis of the distribution of endocrine disrupting substances in the Scheldt Estuary was executed. Water, sediment, suspended solids and biota were analysed for seven groups of chemicals: estrogens, pesticides, organotins, polyaromatic components, polyaromatic hydrocarbons and phenols. Special attention was given to the estuarine mysid shrimp Neomysis integer. Its ecotoxicology and population characteristics were studied in detail. A selection of results of this field study is put forward. Water samples, tested in vitro for their potential to bind with estrogen, revealed more estrogenic activity in the more upstream stations. Concentrations of chlorotriazine herbicides in water samples, were higher in the upstream reaches compared to the downstream sites. Analyses of TBT in mysid shrimps revealed high concentrations (>2mg.kg-1 dry weight) which suggests a high bioaccumulation capacity. Population characteristics results of N. integer show that it has a broader distribution range, with a shift more upstream, in comparison with historical data (Mees et al., 1995). On the other hand, length distribution of developmental stages of N. integer along the estuary indicates some environmental stress, caused by the estuarine gradient or by pollutants. Some hypotheses will be put forward to explain these patterns
Lateral diffusion and retrograde movements of individual cell surface components on single motile cells observed with Nanovid microscopy
A recently introduced extension of video-enhanced light microscopy, called Nanovid microscopy, documents the dynamic reorganization of individual cell surface components on living cells. 40-microns colloidal gold probes coupled to different types of poly-L-lysine label negative cell surface components of PTK2 cells. Evidence is provided that they bind to negative sialic acid residues of glycoproteins, probably through nonspecific electrostatic interactions. The gold probes, coupled to short poly-L-lysine molecules (4 kD) displayed Brownian motion, with a diffusion coefficient in the range 0.1-0.2 micron2/s. A diffusion coefficient in the 0.1 micron2/s range was also observed with 40-nm gold probes coupled to an antibody against the lipid-linked Thy-1 antigen on 3T3 fibroblasts. Diffusion of these probes is largely confined to apparent microdomains of 1-2 microns in size. On the other hand, the gold probes, coupled to long poly-L-lysine molecules (240 kD) molecules and bound to the leading lamella, were driven rearward, toward the boundary between lamelloplasm and perinuclear cytoplasm at a velocity of 0.5-1 micron/min by a directed ATP-dependent mechanism. This uniform motion was inhibited by cytochalasin, suggesting actin microfilament involvement. A similar behavior on MO cells was observed when the antibody-labeled gold served as a marker for the PGP-1 (GP-80) antigen. These results show that Nanovid microscopy, offering the possibility to observe the motion of individual specific cell surface components, provides a new and powerful tool to study the dynamic reorganization of the cell membrane during locomotion and in other biological contexts as well
Comparison of [18F]DOPA and [68Ga]DOTA-TOC as a PET imaging tracer before peptide receptor radionuclide therapy
BACKGROUND: In treatment of neuroendocrine neoplasms (NENs), confirmation of somatostatin receptor expression with 68Ga-DOTA somatostatin analogues is mandatory to determine eligibility for peptide receptor radionuclide therapy (PRRT). [18F]DOPA can detect additional lesions compared to [68Ga]DOTA-TOC. The aim of this study was to explore differences in tumour detection of both tracers and their relevance for selecting patients for PRRT. We retrospectively studied eight patients with NENs who underwent both [68Ga]DOTA-TOC and carbidopa-enhanced [18F]DOPA PET/CT, before first-time PRRT with [177Lu]DOTA-TATE. Tracer order was influenced due to stock availability or to detect suspected metastases with a second tracer. On CT, disease control was defined as a lesion showing complete response, partial response, or stable disease, according to RECIST 1.1. CRITERIA: RESULTS: Seven patients with in total 89 lesions completed four infusions of 7.4 GBq [177Lu]DOTA-TATE, one patient received only two cycles. Before treatment, [18F]DOPA PET/CT detected significantly more lesions than [68Ga]DOTA-TOC PET/CT (79 vs. 62, p < .001). After treatment, no difference in number of lesions with disease control was found for [18F]DOPA-only (5/27) and [68Ga]DOTA-TOC-only lesions (4/10, p = .25). [18F]DOPA detected more liver metastases (24/27) compared to [68Ga]DOTA-TOC (7/10, p = .006). Six patients showed inpatient heterogeneity in treatment response between [18F]DOPA-only and [68Ga]DOTA-TOC-only lesions. CONCLUSIONS: Response to PRRT with [177Lu]DOTA-TATE was comparable for both [68Ga]DOTA-TOC- and [18F]DOPA-only NEN lesions. [18F]DOPA may be capable of predicting response to PRRT while finding more lesions compared to [68Ga]DOTA-TOC, although these additional lesions are often small of size and undetected by diagnostic CT
Endocrine disruption in the Scheldt estuary distribution, exposure and effects (ENDIS-RISKS). Final report
ENDIS-RISKS is a multidisciplinary, research project conducted by five institutes. This project aimed to assess the distribution, exposure and effects of endocrine disruptors in the Scheldt estuary, with specific attention to invertebrates. The Scheldt estuary is known to be one of the most polluted estuaries in the world. The industrial areas of Ghent and Antwerp are to a large extent responsible for this pollution. To achieve these goals detailed knowledge of the distribution and long-term effects of these substances is needed. This information is crucial for the development of future-oriented policy measures at the national and European level. The project can be divided into four different research phases. In Phase I the occurance and distribution of endocrine disrupting substances in the Scheldt estuary was studied. Water, sediment, suspended solids and biota were sampled 3 times a year for a period of 4 years (2002-2006). In all these matrices, 7 groups of chemicals were analysed: estrogens, pesticides, phthalates, organotins, polyaromatic components (PCBs, PBDEs), polyaromatic hydrocarbons (PAHs) and phenols. All the analyzed chemicals are on the OSPAR list of priority chemicals or are indicated as endocrine disruptors on this list. The different water samples were also tested using in vitro assays to assess their potential to bind to the (human) estrogen and androgen receptor. Phase II evaluated the exposure of biota occuring in the Scheldt estuary to endocrine disrupting substances. Based on the results of the chemical analysis, priority substances were selected. Phase III studied the effects of endocrine disrupting substances occurring in the Scheldt estuary on resident mysid shrimp populations (laboratory and field studies). Substances of concern were selected and tested in the laboratory to evaluate their effects on the estuarine mysid Neomysis integer. In the context of this project, three new assays using invertebrate-specific endpoints were developed to examine the effect of endocrine disrupting chemicals (EDCs) on molting, embryogenesis and vitellogenesis of N. integer. Finally, in Phase IV laboratory and field results were used to perform a preliminary environmental risk assessment of endocrine disruptors in the Scheldt estuary. Samples were collected along the salinity gradiënt of the Scheldt estuary with the RV Belgica. Water samples were taken with Teflon-coated Go-Flo bottles (10L), sediment samples with Van Veen Grab, biota with a hyperbentic sledge, and suspended particulate matter (SPM) was continuously sampled with an Alfa Laval flow-through centrifuge. For the chemical analysis, protocols were developed to analyse estrogens, organotriazine herbicides, organochlorine pesticides, phtalates, organotins, PAHs, PCBs, and PBDEs in the different matrices: i.e. water, sediment, SPM and biota.Experimental studies were performed to analyse growth, molting, embryogenesis and vitellogenesis of N. integer. These studies were needed to develop ecotoxicological assays to evaluate EDCs on these physiological processes. To study growth of N. integer, organisms were individually transferrred in exposure solutions and molts were collected to measure the growth after each molting. To study embryogenesis, embryos were taking out of the marsupium and placed in multiwell plates. Each day survival, developmental stages and hatching was analysed. To study vitellogenesis, vitellin was isolated from eggs with gelfitration and polyclonal antibodies were developed (in rabbits). With the isolated vitellin and the antibodies an enzyme-linked immunosorbent assay (ELISA) was developed. Vitellin was quatified in ovigerous females exposed to test compound in the laboratory and in females collected from the different sampling sites of the Scheldt estuary. In addition to vitellin levels, energy allocation and testosterone metabolism was examined in field collected mysids. Finally, results from population stu
Intra-arterial peptide-receptor radionuclide therapy for neuro-endocrine tumour liver metastases:an in-patient randomised controlled trial (LUTIA)
Purpose: Peptide receptor radionuclide therapy (PRRT) using [177Lu]Lu-DOTATATE has been shown to effectively prolong progression free survival in grade 1–2 gastroenteropancreatic neuroendocrine tumours (GEP-NET), but is less efficacious in patients with extensive liver metastases. The aim was to investigate whether tumour uptake in liver metastases can be enhanced by intra-arterial administration of [177Lu]Lu-DOTATATE into the hepatic artery, in order to improve tumour response without increasing toxicity. Methods: Twenty-seven patients with grade 1–2 GEP-NET, and bi-lobar liver metastases were randomized to receive intra-arterial PRRT in the left or right liver lobe for four consecutive cycles. The contralateral liver lobe and extrahepatic disease were treated via a “second-pass” effect and the contralateral lobe was used as the control lobe. Up to three metastases (> 3 cm) per liver lobe were identified as target lesions at baseline on contrast-enhanced CT. The primary endpoint was the tumour-to-non-tumour (T/N) uptake ratio on the 24 h post-treatment [177Lu]Lu-SPECT/CT after the first cycle. This was calculated for each target lesion in both lobes using the mean uptake. T/N ratios in both lobes were compared using paired-samples t-test. Findings: After the first cycle, a non-significant difference in T/N uptake ratio was observed: T/NIA = 17·4 vs. T/Ncontrol = 16·2 (p = 0·299). The mean increase in T/N was 17% (1·17; 95% CI [1·00; 1·37]). Of all patients, 67% (18/27) showed any increase in T/N ratio after the first cycle. Conclusion: Intra-arterial [177Lu]Lu-DOTATATE is safe, but does not lead to a clinically significant increase in tumour uptake.</p
Influence of an increase in diet structure on milk conjugated linoleic acid content of cows fed extruded linseed
Immuno-modulating properties of saliphenylhalamide, SNS-032, obatoclax, and gemcitabine
Influenza A viruses (IAVs) impact the public health and global economy by causing yearly epidemics and occasional pandemics. Several anti-IAV drugs are available and many are in development. However, the question remains which of these antiviral agents may allow activation of immune responses and protect patients against co- and re-infections. To answer to this question, we analysed immuno-modulating properties of the antivirals saliphenylhalamide (SaliPhe), SNS-032, obatoclax, and gemcitabine, and found that only gemcitabine did not impair immune responses in infected cells. It also allowed activation of innate immune responses in lipopolysaccharide (LPS)- and interferon alpha (IFN alpha)-stimulated macrophages. Moreover, immuno-mediators produced by gemcitabine-treated IAV-infected macrophages were able to prime immune responses in non-infected cells. Thus, we identified an antiviral agent which might be beneficial for treatment of patients with severe viral infections. (C) 2015 The Authors. Published by Elsevier B.V.Peer reviewe
- …