Effects of long-term chlorpyrifos exposure on mortality and reproductive tissues of Banded Gourami (Trichogaster fasciata)
Sumon, Kizar Ahmed ; Yesmin, Most Farzana ; Brink, Paul J. Van den; Bosma, Roel H. ; Peeters, Edwin T.H.M. ; Rashid, Harunur - \ 2019
Journal of Environmental Science and Health. Part B, Pesticides Food Contaminants, and agricultural wastes 54 (2019)7. - ISSN 0360-1234 - p. 549 - 559.
Aquatic environment - fish - histopathology - organophosphate pesticide - reproductive toxicity
This study assessed the long-term toxicity of chlorpyrifos on survival and reproduction of Banded Gourami by using mortality, gonado-somatic index (GSI) and histopathological observations as endpoints. Adult fish were exposed to five different concentrations of chlorpyrifos (0, 15, 50, 150, 500 µg/L) in 15 PVC tanks for 15, 30, 45, 60 and 75 days. Results showed that all male and female fish died after 15 days of 500 µg/L chlorpyrifos exposure. No consistent significant effect was observed for both male and female GSI. Furthermore, results showed dose- and time-dependent histopathological alterations for both ovary and testes. The 60-d No Observed Effect Concentration (NOEC) for most histopathological alterations of Banded Gourami ovary and testes was 50 μg/L, while 60-d NOEC for mortality of both male and female fish was < 15 μg/L. The results show that the long-term exposure to chlorpyrifos not only affect the reproductive tissues of Banded Gourami at exposure concentrations but also cause their mortality. Future studies should evaluate effects at lower concentrations.
Horizontal transmission dynamics of White spot syndrome virus by cohabitation trials in juvenile Penaeus monodon and P. vannamei
Ngo Xuan, T. ; Verreth, J.A.J. ; Vlak, J.M. ; Jong, M.C.M. de - \ 2014
Preventive Veterinary Medicine 117 (2014)1. - ISSN 0167-5877 - p. 286 - 294.
yellow head virus - litopenaeus-vannamei - experimental-infection - baculovirus wsbv - commodity shrimp - genome sequence - oral routes - wssv - japonicus - histopathology
White spot syndrome virus (WSSV), a rod-shaped double-stranded DNA virus, is an infectious agent causing fatal disease in shrimp farming around the globe. Within shrimp populations WSSV is transmitted very fast, however, the modes and dynamics of transmission of this virus are not well understood. In the current study the dynamics of disease transmission of WSSV were investigated in small, closed populations of Penaeus monodon and Penaeus vannamei. Pair cohabitation experiments using PCR as a readout for virus infection were used to estimate transmission parameters for WSSV in these two species. The mortality rate of contact-infected shrimp in P. monodon was higher than the rate in P. vannamei. The transmission rate parameters for WSSV were not different between the two species. The relative contribution of direct and indirect transmission rates of WSSV differed between the two species. For P. vannamei the direct contact transmission rate of WSSV was significantly lower than the indirect environmental transmission rate, but for P. monodon, the opposite was found. The reproduction ratio R0 for WSSV for these two species of shrimp was estimated to be above one: 2.07 (95%CI 1.53, 2.79) for P. monodon and 1.51 (95%CI 1.12, 2.03) for P. vannamei. The difference in R0 between the two species is due to a lower host mortality and hence a longer infectious period of WSSV in P. monodon.
The Isolated Chicken Eye test to replace the Draize test in rabbits : from development to implementation: “The long and winding road”
Prinsen, M.K. - \ 2014
Wageningen University. Promotor(en): Ruud Woutersen; C.F.M. Hendriksen, co-promotor(en): C.A.M. Krul. - Wageningen : Wageningen University - ISBN 9789462570030 - 184
ogen - konijnen - kippen - laboratoriumdieren - alternatieven voor dierproeven - dierproeven - toxiciteit - toxicologie - histopathologie - dierenwelzijn - eyes - rabbits - fowls - laboratory animals - animal testing alternatives - animal experiments - toxicity - toxicology - histopathology - animal welfare
Dit proefschrift beschrijft de ontwikkeling, optimalisatie, validatie (binnen TNO) en toepassing van een alternatieve test met geïsoleerde ogen van kippen (de Isolated Chicken Eye, kortweg de ICE test) en in bredere zin de internationale validatie en acceptatie van de ICE test door overheidsinstanties.
Hyperplasia of the lymphoepithelium of NALT in rats but not in mice upon 28-day exposure to 15 ppm formaldehyde vapor
Kuper, C.F. ; Oostrum, L. van; Ma-Hock, I. ; Durrer, S. ; Woutersen, R.A. - \ 2011
Experimental and Toxicologic Pathology 63 (2011). - ISSN 0940-2993 - p. 25 - 32.
lymphoid-tissue - inhalation exposure - nodes - histopathology - malignancies - mucosa
To investigate if local lymphoid tissues are a target of FA, nasopharynx-associated lymphoid tissues (NALT) and upper-respiratory tract-draining lymph nodes were examined in a 28-day inhalation study with FA vapor in Fischer-344 rats and B6C3F1 mice. Paraffin-embedded tissues were sectioned and stained with H&E or stained immunohistochemically for cell proliferation (BrdU incorporation). Light microscopy revealed simple hyperplasia of NALT lymphoepithelium of rats exposed to 15 ppm and an increased proliferation rate of the epithelial cells. Principal component (discriminant) analysis of rat NALT and lymph nodes data did not reveal other effects or effects at lower exposure levels. Mice tissues were not affected. It was concluded that hyperplasia of the lymphoepithelium of NALT of rats exposed to 15 ppm was the only distinct effect of FA vapor on local lymphoid tissues (NALT and lymph nodes) of Fischer-344 rats and B3C3F1 mice.
Direct detection and genotyping of Toxoplasma gondii in meat samples using magnetic capture and PCR
Opsteegh, M. ; Langelaar, M. ; Sprong, H. ; Hartog, L. ; Craeye, S. de; Bokken, G. ; Ajzenberg, D. ; Kijlstra, A. ; Giessen, J. van der - \ 2010
International Journal of Food Microbiology 139 (2010)3. - ISSN 0168-1605 - p. 193 - 201.
polymerase-chain-reaction - congenital toxoplasmosis - tissue cysts - sheep - dna - infection - pigs - histopathology - diagnosis - bioassay
Different transmission routes, including the ingestion of undercooked meat, can result in Toxoplasma gondii infection in humans. The development of effective prevention strategies is hampered by a lack of quantitative information on the contamination level of different types of meat. Therefore, we developed a method for detection and quantification of T. gondii. The method involved preparation of crude DNA extract from hundred gram samples of meat, magnetic capture of T. gondii DNA and, quantitative real-time PCR targeting the T. gondii 529-bp repeat element. The detection limit of this assay was approximately 230 tachyzoites per 100 g of meat sample. There was a linear relation between the number of parasites added to the samples and Cp-values. Results obtained with the PCR method were comparable to bioassay results for experimentally infected pigs, and to serological findings for sheep. In addition, the T. gondii in 50% of the positive sheep samples could be genotyped by sequencing of the GRA6 gene, after isolation of the gene by magnetic capture. Two subtypes of GRA6 type II were identified in the 16 samples from sheep. For seven samples, the identification of T. gondii as type II was confirmed by microsatellite typing. The PCR method can be used as an alternative to bioassay for detection and genotyping of T. gondii, and to quantify the organism in meat samples of various sources
Diet, lifestyle, heritable factors and colorectal carcinogenesis: associations with histopathological and molecular endpoints
Wark, P.A. - \ 2007
Wageningen University. Promotor(en): Pieter van 't Veer; Frans Kok, co-promotor(en): M.P. Weijenberg. - [S.l.] : S.n. - ISBN 9789085045755 - 191
colorectaal kanker - carcinogenese - dieet - levensstijl - overerving - histopathologie - fruit - groenten - colorectal cancer - carcinogenesis - diet - lifestyle - inheritance - histopathology - fruit - vegetables
Background: Diet, lifestyle and heritable factors have been related to colorectal cancer risk; to date, their relevance to the overall scope of colorectal carcinogenesis, has not been clearly established.
Aim and Methods: To evaluate whether distinguishing colorectal tissue by its histopathological and molecular characteristics sheds further light on the etiology of colorectal cancer. Five research questions addressed associations between diet, lifestyle and heritable factors, and specific tissue characteristics.
Results: First, we observed that consumption of fruits, in particular citrus fruits, was associated with increased rectal glutathione S-transferase activity in a cross-sectional study of 94 Dutch individuals. Consumption of cruciferous vegetables was also associated with increased activity, but only among individuals who carried the GSTM1 genotype.
Second, we observed that intake of vitamin B2 was inversely associated with adenomas with a K-ras mutation (n=81) but not with adenomas without a K-ras mutation (n=453) in a case-control study conducted in the Netherlands. A positive association with monounsaturated fat was confined to K-ras mutation-negative adenomas. We found indications for differential associations with some additional factors, but the epidemiological evidence on risk factors and K-ras mutations remains inconsistent.
Third, in a cohort study of 26,769 American men, we observed that most risk factors were similarly associated with advanced (=1cm or with any villous characteristics or carcinoma in situ) and non-advanced colorectal adenomas after 17 years of follow-up. However, smoking had a stronger positive association with advanced adenomas than with non-advanced adenomas, and ahigh glycemic index was inversely associated with advanced but not with non-advanced adenomas.
Fourth, associations with family history of colorectal cancer were stronger for men with multiple distal adenomas than for men with a single distal adenoma at first diagnosis, in the aforementioned cohort study among US men. Associations between family history, and advanced and non-advanced adenomas, were of similar strength, but a tendency towards a somewhat stronger association with non-advanced adenomas was found.
Fifth, fruit consumption was inversely associated with hMLH1 protein-deficient colon cancer (n=54) but not with hMLH1 protein-proficient colon cancer (n=387) in a cohort study of 120,852 people who were followed-up over 7.3 years, while ignoring information from the initial 2.3 years of follow-up. Clear associations with consumption of vegetables, or nutrients related to fruits and vegetables, could not be detected.
Conclusions: We showed that distinguishing colorectal tumors by their histopathological and molecular characteristics may indeed shed further light on the role of diet, lifestyle and heritable factors in colorectal carcinogenesis. Such an approach may alleviate some of the weaknesses of traditional epidemiology, but also adds another layer of complexity. It is a challenge for the future to develop a framework into which specific associations can be integrated, using risk markers signaling the molecular and biochemical pathways from normal to cancerous tissue.
Bodemverontreiniging in de Biesbosch en doorvergiftiging naar kleine zoogdieren
Bosveld, A.T.C. ; Bie, P.A.F. de; Hamers, T. - \ 2003
Wageningen : Alterra (Alterra-rapport 654) - 64
bodemverontreiniging - zware metalen - polychloorbifenylen - vergiftiging - sorex araneus - muizen - muridae - fauna - histopathologie - enzymen - nederland - noord-brabant - zuid-holland - biesbosch - soil pollution - heavy metals - polychlorinated biphenyls - poisoning - sorex araneus - mice - muridae - fauna - histopathology - enzymes - netherlands - noord-brabant - zuid-holland - biesbosch
In de Biesbosch worden bij overstromingen sedimenten afgezet op landbodem. Hiermee komen verontreinigingen zoals PAK's, PCB's en zware metalen beschikbaar voor de terrestrische voedselketen. Onderzocht is in welke concentraties deze verontreinigingen voorkomen in de landbodem en in hoeverre doorvergiftiging optreedt naar kleine zoogdieren. De voornamelijk planten en zaden etende woelmuis en de op bodemfauna (o.a. regenwormen) foeragerende bosspitsmuis zijn onderzocht. Dieren uit regelmatig overstroomde gebieden blijken hogere concentraties verontreinigingen in hun lichaam te hebben en vertonen duidelijke effecten op cytochroom P450 enzymfuncties (o.a. EROD). Daarnaast treden bij deze dieren in sommige gevallen ook effecten op in verschillende organen (lever, nier, gonaden) of op het lichaamsgewicht.
Toepassing van beeldanalyse in het histopathologisch onderzoek
Bakker, R. - \ 1999
Wageningen : RIKILT-DLO (Rapport / RIKILT 99.002) - 14
histopathologie - afbeelden - histopathology - imagery