• Title/Summary/Keyword: laboratory

Search Result 41,452, Processing Time 0.101 seconds

Three Month Subacute Toxicity Study of Ginkgo Biloba Extract(EGb 761) in Rats

  • Lee, Yong-Soon;Nam, Jeong-Seok;Che, Jeong-Hwan;Lee, Suk-Man;Yang, Jae-Man;Kang, Byeong-Cheol;Lee, Hak-Mo;Park, Jae-Hak;Chai, Chan-Hee;Kang, Sung-An
    • Toxicological Research
    • /
    • v.12 no.1
    • /
    • pp.113-119
    • /
    • 1996
  • Group of 40 male and 40 female Sprague-Dawley rats was given daily intravenous injections of different dosage of Ginkgo biloba extract(EGb 761), 7.5 mg/kg/day (low dosage group), 15 mg/kg/day (middle dosage group), or 30 mg/kg/day (high dosage group)for 3 month by tail vein according to Established Regulation of Korean National Institute of Safety Research (1994. 4. 14). Appearance, behavior, mortality, and food consumption of rats of treated groups were not affected during the experimental periods. No significant Ginkgo biloba extract(EGb 761)-related changes were found in urinalysis, hematology, serum chemistry, and organ weight. No histopathological lesions were seen in both control and treatment groups. Our results strongly suggest that no toxic changes were found in rat treated intravenously with Ginkgo biloba extract(EGb 761)for 3 month.

  • PDF

Estimation of L-threonine requirements for Longyan laying ducks

  • Fouad, A.M.;Zhang, H.X.;Chen, W.;Xia, W.G.;Ruan, D.;Wang, S.;Zheng, C.T.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.30 no.2
    • /
    • pp.206-210
    • /
    • 2017
  • Objective: A study was conducted to test six threonine (Thr) levels (0.39%, 0.44%, 0.49%, 0.54%, 0.59%, and 0.64%) to estimate the optimal dietary Thr requirements for Longyan laying ducks from 17 to 45 wk of age. Methods: Nine hundred Longyan ducks aged 17 wk were assigned randomly to the six dietary treatments, where each treatment comprised six replicate pens with 25 ducks per pen. Results: Increasing the Thr level enhanced egg production, egg weight, egg mass, and the feed conversion ratio (FCR) (linearly or quadratically; p<0.05). The Haugh unit score, yolk color, albumen height, and the weight, percentage, thickness, and breaking strength of the eggshell did not response to increases in the Thr levels, but the albumen weight and its proportion increased significantly (p<0.05), whereas the yolk weight and its proportion decreased significantly as the Thr levels increased. Conclusion: According to a regression model, the optimal Thr requirement for egg production, egg mass, and FCR in Longyan ducks is 0.57%, while 0.58% is the optimal level for egg weight from 17 to 45 wk of age.

Xylazole inhibits NO-cGMP pathway in fetal rat nerve cells

  • Wang, Xinyu;Wu, Yue;Liu, Lin;Bai, Hui;Zhang, Zhiheng;Zhao, Mingchao;Ma, Tianwen;Song, Xiaopeng;Jia, Lina;Lv, Liangyu;Yu, Yue;Xu, Xinyu;Chen, Hong;Gao, Li
    • Journal of Veterinary Science
    • /
    • v.23 no.1
    • /
    • pp.16.1-16.13
    • /
    • 2022
  • Background: Xylazole (Xyl) is a veterinary anesthetic that is structurally and functionally similar to xylazine. However, the effects of Xyl in vitro remain unknown. Objectives: This study aimed to investigate the anesthetic mechanism of Xyl using fetal rat nerve cells treated with Xyl. Methods: Fetal rat nerve cells cultured for seven days were treated with 10, 20, 30, and 40 ㎍/ mL Xyl for 0, 5, 10, 15, 20, 25, 30, 45, 60, 90, and 120 min. Variations of amino acid neurotransmitters (AANTs), Nitric oxide-Cyclic GMP (NO-cGMP) signaling pathway, and ATPase were evaluated. Results: Xyl decreased the levels of cGMP and NO in nerve cells. Furthermore, Xyl affected the AANT content and Na+-K+-ATPase and Ca2+-Mg2+-ATPase activity in nerve cells. These findings suggested that Xyl inhibited the NO-cGMP signaling pathway in nerve cells in vitro. Conclusions: This study provided new evidence that the anesthetic and analgesic effects of Xyl are related to the inhibition of the NO-cGMP signaling pathway.

Synchrotron Grazing Incidence X-ray Scattering and Its Applications in Polymer Nanotechnology

  • Ree, Moon-Hor;Lee, Byeong-Du;Yoon, Jin-Hwan;Heo, Kyu-Young;Jin, Kyeong-Sik;Jin, Sang-Woo;Kim, Hyun-Chul;Kim, Gha-Hee;Choi, Seung-Chul;Oh, Weon-Tae;Park, Young-Hee;Hwang, Yong-Taek;Kim, Jong-Seong
    • Proceedings of the Polymer Society of Korea Conference
    • /
    • 2006.10a
    • /
    • pp.120-120
    • /
    • 2006
  • In our study grazing incidence X-ray scattering (GIXS) measurements with synchrotron radiation sources were conducted statically and in-situ for a series of nanoscale thin films prepared from nanoporous dielectrics, block copolymers, brush polymers, and molecular assemblies. All GIXS measurements were performed at the Pohang Accelerator Laboratory. The measured scattering data were analyzed in detail by using newly developed GIXS scattering theory. All GIXS results will be discussed in details with considering the materials chemistry and nanostructure formation process parameters.

  • PDF