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- Ankarberg, Emma, et al.
(author)
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Increased susceptibility to adult paraoxon exposure in mice neonatally exposed to nicotine
- 2004
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In: Toxicological Sciences. - : Oxford University Press (OUP). - 1096-6080 .- 1096-0929. ; 82:2, s. 555-561
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Journal article (peer-reviewed)abstract
- Low-dose exposure of neonatal mice to nicotine has earlier been shown to induce an altered behavioral response to nicotine in adulthood. Organophosphorus insecticides are known to affect the cholinergic system by inhibition of acetylcholinesterase. This study was undertaken to investigate whether neonatal exposure to nicotine makes mice more susceptible to a known cholinergic agent. Neonatal, 10-day-old, male mice were exposed to nicotine-base (33 microg/kg body weight) or saline s.c. twice daily on five consecutive days. At 5 months of age the animals were exposed to paraoxon (0.17 or 0.25 mg/kg body weight [29% and 37% inhibition of cholinesterase, respectively]) or saline sc every second day for 7 days. Before the first paraoxon injection, the animals were observed for spontaneous motor behavior. The spontaneous motor behavior test did not reveal any differences in behavior between the treatment groups. Immediately after the spontaneous behavior test, the animals received the first injection of paraoxon and were observed for acute effects of paraoxon on spontaneous motor behavior. The acute response to paraoxon in the spontaneous motor behavior test was a decreased level of activity in mice neonatally exposed to nicotine. Control animals showed no change in activity. Two months after the paraoxon treatment, the animals were again tested for spontaneous motor behavior. Animals neonatally exposed to nicotine and exposed to paraoxon as adults showed a deranged spontaneous motor behavior, including hyperactivity and lack of habituation.
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| 2. |
- Bäcklin, Britt-Marie, et al.
(author)
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Proliferative Effects of Estradiol, Progesterone, and Two CB Congeners and Their Metabolites on Gray Seal (Halichoerus grypus) Uterine Myocytes in Vitro
- 2003
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In: Toxicological Sciences. - : Oxford University Press (OUP). - 1096-6080 .- 1096-0929. ; 75:1, s. 154-160
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Journal article (peer-reviewed)abstract
- Gray seal females living in the Baltic Sea have been found to exhibit a high prevalence of uterine leiomyomas. These animals are also known to accumulate lipid-soluble PCBs in their blubber. PCBs have documented endocrine-disrupting effects; to investigate whether the PCBs could be part of the genesis of uterine smooth muscle tumors in this species, gray seal myometrial cell cultures were exposed to two CBs and their metabolites, as well as to estradiol and progesterone, after which the effects were analyzed in terms of proliferative activity by measurements of BrdU absorbance and protein content. Progesterone was found to have an inhibitory effect, whereas one CB acted as a stimulant on the myometrial cell proliferation. One of the CB metabolites also seemed to have an inhibitory effect, although this could not be statistically verified. These results suggest that some CBs have effects on uterine myometrial cell proliferation in gray seals and, thus, may also take part in the growth regulation of uterine leiomyomas.
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- Suuronen, Erik J., et al.
(author)
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Functional innervation in tissue engineered models for in vitro study and testing purposes
- 2004
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In: Toxicological Sciences. - : Oxford University Press (OUP). - 1096-6080 .- 1096-0929. ; 82:2, s. 525-533
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Journal article (peer-reviewed)abstract
- The biotechnology industry is rapidly expanding and the emerging field of tissue engineering is projected to have a high impact in the near future. Recently the field of cellular, drug, and prosthetic delivery has melded with the field of tissue engineering to make simulated tissues. In addition to their roles as tissue substitutes for transplantation, these simulated tissues may provide more accurate models and environments for toxicology testing and the study of peripheral nerves. The current study demonstrates the importance of innervation, in general, for the function of engineered tissues. We observe that the presence of nerves in a tissue engineered (TE) human cornea model enhances the growth of the epithelium and the formation of its protective mucin layer. Innervation also confers protection to the epithelium from chemical insult, as determined by the level of post-treatment epithelial cell death. We demonstrate differential responses of the nerves to chemical stimuli by changes in intracellular sodium as measured by 2-photon microscopy. The 2-photon imaging techniques also allow for the visualization and study of the fine sensory axon fibers within the 3-dimensional tissue. This work demonstrates a role for innervation in the protective quality and function of the engineered tissue, and the potential to use the nerves themselves as indicators of the severity of an insult. These results are important to consider for the development of any optimized TE models for in vitro study and testing purposes.
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| 10. |
- Viberg, Henrik, et al.
(author)
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Investigations of strain and/or gender differences in developmental neurotoxic effects of polybrominated diphenyl ethers in mice
- 2004
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In: Toxicological Sciences. - : Oxford University Press (OUP). - 1096-6080 .- 1096-0929. ; 81:2, s. 344-353
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Journal article (peer-reviewed)abstract
- Polybrominated diphenyl ethers (PBDEs), one class of flame retardants used to suppress or inhibit the risk of fire, are regularly found in the environment and in human milk. The present study shows that neonatal exposure to a widely, environmentally found PBDE, 2,2',4,4',5-pentaBDE (PBDE 99), can induce developmental neurotoxic effects, such as changes in spontaneous behavior (hyperactivity), effects that are dose-response related and worsen with age. These changes are seen in C57/Bl mice of both sexes. Neonatal C57/Bl male and female mice were orally exposed on day 10 to 0.4, 0.8, 4.0, 8.0, or 16 mg PBDE 99/kg body weight. Spontaneous behavior (locomotion, rearing, and total activity) was observed in two-, five-, and eight-month-old mice. The behavior tests showed that the effects were dose-response and time-response related for both male and female mice. The observed developmental neurotoxic effects seen for PBDE 99, in C57/Bl mice, are similar to effects seen for 2,2',4,4'-tetraBDE (PBDE 47), PBDE 99, 2,2',4,4',5,5'- hexaBDE (PBDE 153), 2,2',3,3',4,4',5,5',6,6'-decaBDE (PBDE 209) and for certain PCBs, in male NMRI mice. Furthermore, the effects of PBDEs appear to be as potent in female mice as in male mice, and as potent in C57/Bl mice as in NMRI mice, concerning developmental neurotoxicity.
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