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1

Monocykliczne poliprenylowane acylofloroglucynole z szyszek chmielu (Humulus Lupulus) - perspektywa stosowania w żywieniu zwierząt

100%
Stypula-Trebas S.
Pasze Przemysłowe
|
2018
|
tom 27
|
nr 4
2

Jakość pasz dla zwierząt laboratoryjnych jako czynnik otrzymanych wyników badań

63%
Radko L., Stypula-Trebas S.
Pasze Przemysłowe
|
2018
|
tom 27
|
nr 2
3

Comparison of extraction and cleanup procedures for the determination of PCDD/Fs in feed samples with the calux bioassay

63%
Stypula-Trebas S., Piskorska-Pliszczynska J.
Bulletin of the Veterinary Institute in Puławy
|
2010
|
tom 54
|
nr 4
The efficiency of four extraction techniques (shaking extraction, column extraction, accelerated solvent extraction (ASE), and ultrasonic assisted extraction) and two clean-up procedures was evaluated in order to find the best procedure. The ASE proved to be the best extraction method with the highest recovery rales (84%-91%) and imprecision less than 15%. Application of the three- column cleanup procedure delivered slightly better cleanup efficiency in comparison with two-step cleanup but the use of two columns is less time consuming, cost-effective, and enabled to process more samples with the bioassay.
4

Związki hormonalne aktywne w środowisku a zagrożenia zdrowia publicznego

63%
Minta M., Stypula-Trebas S.
Medycyna Weterynaryjna
|
2010
|
tom 66
|
nr 08
s.525-529,tab.,bibliogr.
This article is a review of recently published papers dealing with the possible participation of environmental hormonally active compounds (natural and synthetic) in the ethiology of reproductive and other health disorders in animals and man. For some "old" synthetic chemicals (DDT, PCBs, dioxins, diethylstilbestrol, bisphenol A, atrazine and tributyltin) there is a link to the impact on wild animals. It has been hypothesized that in humans these compounds may be responsible for the increased incidence of breast and testicular cancer as well as for reproductive disorders. They generally occur at nontoxic concentrations, but exposure to their mixtures seems to be a major medical challenge. The food and drinking water are the main routes of exposure. During last decades much concern is focused on new groups of chemicals such as brominated flame retardants, phthalates, perfluorinated chemicals, parabens and veterinary drugs (anabolics).
5

Wykrywanie i ocena aktywności związków hormonalnie aktywnych

63%
Minta M., Stypula-Trebas S.
Medycyna Weterynaryjna
|
2012
|
tom 68
|
nr 01
During the last two decades concerns have been raised regarding the possible harmful effects of exposure to certain chemicals (natural and synthetic) that can modulate or disrupt the endocrine system (endocrine disrupters, EDs). Their identification and assessment is complicated by a number of mechanisms on which they act. As a result a variety of in silico/in vitro/in vivo methods are used. In this paper the most valuable methods for initial assessment, screening and testing are reviewed. To protect public health, future risk assessment of endocrine disrupters must take into account exposure to the mixtures in which different compounds can interact. The development of fast and sensitive bioassays is crucial to the achievement of this goal.
6

Optymalizacja testu wzrostu masy macicy i testu Hershbergera na chomikach z użyciem związków modelowych

51%
Radko L., Minta M., Stypula-Trebas S., Zmudzki J.
Annals of Warsaw University of Life Sciences - SGGW. Animal Science
|
2011
|
tom 48
7

Differential toxicities of albendazole and its two main metabolites to Balb/c 3T3, HepG2, and FaO lines and rat hepatocytes

51%
Radko L., Minta M., Stypula-Trebas S.
Journal of Veterinary Research
|
2016
|
tom 60
|
nr 4
8

Influence of fluoroquinolones on viability of Balb/c 3T3 and HepG2 cells

51%
Radko L., Minta M., Stypula-Trebas S.
Bulletin of the Veterinary Institute in Puławy
|
2013
|
tom 57
|
nr 4
The cytotoxic potential of fluoroquinolones (enrofloxacin, ciprofloxacin, difloxacin, sarafloxacin, danofloxacin, norfloxacin and marbofloxacin) was investigated using mouse fibroblasts Balb/c 3T3 and human hepatoma HepG2 cell lines. The cells were exposed for 24, 48, and 72 h to drugs at eight concentrations ranged from 0.78 to 100 µg/mL. Four independent cytotoxicity assays were applied, in which various endpoints were assessed: mitochondrial activity - MTT reduction, lysosomal activity - neutral red uptake, total protein content, and cellular membrane integrity - lactate dehydrogenase release. Mean effective cytotoxic concentrations (EC₅₀) calculated at different time points from concentration-response curves ranged from 10 to 100 µg/mL. The most affected endpoint in both cell lines was mitochondrial activity. The EC₅₀₋MTT₋₇₂ₕ <10 µg/mL was found for difloxacin, marbofloxacin (fibroblasts), sarafloxacin, and norfloxacin (HepG2). The data shows that cytotoxicity of the fluoroquinolones appears after longer exposure of both cell cultures to these compounds.
9

Ocena aktywności hormonalnej prenyloflawonoidu chmielowego w kontekście stosowania odpadów browarnianych w żywieniu zwierząt

51%
Stypula-Trebas S., Radko L., Posyniak A.
Pasze Przemysłowe
|
2018
|
tom 27
|
nr 2
10
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Estrogenic activity of commercial milk as revealed in immature hamster uterotrophic assay – pilot study

51%
Radko L., Minta M., Stypula-Trebas S.
Roczniki Państwowego Zakładu Higieny
|
2017
|
tom 68
|
nr 3
Background. The risk for public health posed by endocrine disruptors present in food is relatively new issue. Our current understanding of human exposure is mainly based on the residue analysis of selected compounds. With such approach potential, effects of mixtures, including so-far unidentified compounds are not taken into consideration. Therefore, the knowledge of overall hormonal activity in food samples is of big importance. Objective. Milk and dairy products are a rich source of estrogens but very rarely undergo testing for estrogenic activity. For this reason the rodent uterotrophic bioassay is one of the most useful tool. This preliminary study was conducted in immature hamsters to assess commercially available milk. The endpoint measured was uterine weight increase. Material and methods. Fifteen-day old females received ad libitum throughout 7 days commercially available milk i.e. raw goat’s, raw cow’s, processed 3.2% UHT, and for comparison soy milk. The animals of negative control group received water but positive control group got 17β - estradiol (E2) at the concentration of 100 ng/ml. Results. All samples of milk showed estrogenic activity as follow: goat’s >cow’s >soy >processed milk. Significant increase of uteri weights were recorded in goat’s (p<0.001) and cow’s milk (p<0.01). However, the activity was approximately 5-fold lower than induced by 17β-estradiol. The ratio uterine weight/body weight (%) in negative control was 0.096%, in milk experimental groups ranged from 0.112% to 0.153% and in positive control this value was 0.493%. Conclusion. The results suggest that commercially available milk has a weak uterotrophic activity. Further in vivo and in vitro studies are warranted to gain more insight into the estrogenic risk from milk and other dairy products.
11

Determination of melamine cytotoxicity

51%
Radko L., Minta M., Stypula-Trebas S., Zmudzki J.
Bulletin of the Veterinary Institute in Puławy
|
2010
|
tom 54
|
nr 2
223-228
Cytotoxic potential of melamine was evaluated with the use of two in vitro models i.e. cell cultures of rat hepatoma (line FaO) and rat skeletal muscle (line L6). The cultures were exposed for 24, 48, and 72 h to melamine at eight concentrations, ranged from 0.01 to 10 mM. Four different assays were applied in which various biochemical endpoints were assessed: mitochondrial activity - MTT reduction assay, proliferation - Commassie Brilliant Blue (CBB) dye binding assay, lysosomal activity - neutral red uptake (NRU) assay, and membrane integrity - LDH release assay. Effective concentrations (EC₂₀, EC₅₀, EC₈₀) were calculated from concentration-response curves, and then they were averaged over three independently conducted experiments. It was found that MTT assay was the most sensitive to this compound. After 48 h exposure EC₅₀ values (mM, mean ± SD) for FaO and L6 cells were 6.4 ± 0.62, and 8.2 ± 1.51, respectively. The inhibition of lysosomal activity measured by NRU assay, and damage of plasma membrane measured by LDH assay were detected in L6 (but not in FaO) cells; however, the effects took place after longer (72 h) exposure. At that time EC₅₀ values were 5.2 mM and 9.2 mM for NRU and LDH, respectively. In spite of the low cytotoxicity of melamine, more studies are needed for hazard identification and characterization of the compound.
12

Cytotoxic effects of the synthetic oestrogens and androgens on Balb/c 3T3 and HepG2 cells

51%
Minta M., Radko L., Stypula-Trebas S., Zmudzki J.
Bulletin of the Veterinary Institute in Puławy
|
2014
|
tom 58
|
nr 4
The aim of the study was to test and compare the cytotoxic potential of two synthetic oestrogens: diethylstilboestrol (DES) and ethinyloestradiol (EE₂) and two androgens: testosterone propionate (TP) and trenbolone (TREN) on two cell lines. The fibroblast cell line Balb/c 3T3 and the hepatoma cell line HepG2 were selected. To get more insight into the mode of toxic action, four methods were used, which evaluated different biochemical endpoints: mitochondrial activity (3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide reduction assay), lysosomal activity (neutral red uptake assay), total protein content, and lactate dehydrogenase release. Cytotoxicity was assessed after 24, 48, and 72 h exposure to eight concentrations ranging from 0.78 to 100 µg/mL. Concentration- and time- dependent effects were observed. Depending on the line and assay used, half maximal effective concentration after 72 h (EC₅₀₋₇₂ₕ) values ranged as follows: DES 1-13.7 µg/mL (Balb/c 3T3) and 3.7-5.2 µg/mL (HepG2); EE₂ 2.1-14.3 µg/mL (Balb/c 3T3) and 1.8-7.8 µg/mL (HepG2); TP-14.9-17.5 µg/mL (Balb/c 3T3), and 63.9- 100 µg/mL (HepG2); and TREN 11.3-31.4 µg/mL (Balb/c 3T3) and 12.5-59.4 µg/mL (HepG2). The results revealed that oestrogens were more toxic than androgens and the most affected endpoint was mitochondrial activity. In contrast to oestrogens, for which EC₅₀₋₇₂ₕ values were similar in both lines and by all assays used, Balb/c 3T3 cells were more sensitive than HepG2 cells to TP.
13

Influence of dietary soy isoflavones on immature hamster uterotrophic and Hershberger assays

45%
Minta M., Radko L., Stypula-Trebas S., Wozniak B., Zmudzki J.
Bulletin of the Veterinary Institute in Puławy
|
2013
|
tom 57
|
nr 4
To select appropriate diet for hamsters used in the uterotrophic and Hershberger assays two rodent diets were compared: Murigran (Agropol, Poland) and Altromin 7010 (Altromin Spezialfutter GmbH&Co., Germany). The contents of bioactive compounds in feeds were evaluated by liquid chromatography, and their oestrogenic activity by yeast enhanced green fluorescent protein assay. In opposition to Altromin, Murigran contained high amounts (µg/kg) of genistein (765 600) and daidzein (132 000), and the oestrogenic activity of these compounds, expressed as 17ß-oestradiol equivalent concentration (EEQ), was found to be 9.54 µg EEQ/kg. In in vivo study, Murigran induced a high degree of oestrogenisation in immature hamsters, and females failed to exhibit a normal uterine response to recommended dose of a model oestrogen agonist 17α-ethinyloestradiol. There was no influence of the diet on the weight of five accessory sex organs (ASO): ventral prostate, seminal vesicles with coagulating glands, levator ani bulbocavernosus muscles, Cowper's glands, and glans penis of control males. However, the impact on ASO response to model androgen agonist, testosterone propionate was observed. The obtained results provide the evidence that phytooestrogen-rich feed modulates the oestrogenic and androgenic response to chemicals.
14

Usefulness of immature golden hamster (Mesocricetus auratus) as a model for uterotrophic assay

45%
Radko L., Minta M., Jasik A., Stypula-Trebas S., Zmudzki J.
Bulletin of the Veterinary Institute in Puławy
|
2015
|
tom 59
|
nr 4
The present study assessed the sensitivity of immature hamster uterotrophic assay to reference oestrogen agonists/antagonists in order to develop a sensitive model for evaluation of endocrine-active compounds in diets. After performing a baseline for control animals, the sensitivity of immature females (postnatal day 18) to reference compounds was evaluated in a three-day uterotrophic assay. The absolute and adjusted dry uterine weights, fold induction over control for absolute wet uterine weight, and wet uterine weight/body weight ratio (%) were used as endpoints. The significantly active doses for reference oestrogens were as follows: 0.6 µg/kg for 17α-ethinyloestradiol (s.c.): 1 µg/kg/day (s.c.) and 40 µg/kg (p.o.) for diethylstilboestrol; 40 mg/kg (s.c.) and 160 mg/kg (p.o.) for bisphenol A. Co-treatment with tamoxifen at a dose of 1 mg/kg significantly antagonised the uterotrophic effect induced by 1 µg/kg 17α-ethinyloestradiol, and showed the attenuated proliferative effect in histopathological examination. We found immature hamster uterotrophic assay as a sensitive model that could be a good alternative to the rat assay.
15

Wpływ mykotoksyn wykrywanych w paszach na rozwój ryb Danio rerio

45%
Radko L., Jedziniak P., Jakubaszek A., Stypula-Trebas S., Posyniak A.
Pasze Przemysłowe
|
2018
|
tom 27
|
nr 2
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