- Anterior Neck Approach for 4-vessel Occlusion in Rats: A Study for Immunohistological Changes and the Effects of Aminoguanidine on Neuronal Cell Death in the Hippocampus.
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Young Jun Ahn, Ki Young Choi, Gu Kang, Yong Seok Kim, Seungkoo Lee, Il Young Cheong, Keun Woo Kim
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Korean J Pathol. 2007;41(6):393-405.
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 Abstract
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- BACKGROUND
Clinically relevant cerebral ischemia is encountered most frequently as a cardiac arrest or as single or multiple occlusions of the intracranial or extracranial cerebral arteries. Yamaguchi et al. has introduced a one-stage anterior approach to occlude the common carotid arteries (CCAs) and vertebral arteries (VAs).
METHODS
We used a 2-stage anterior approach for producing transient global ischemia by 4-vessel occlusion (4-VO). Four to five days after electrocauterization of two VAs using the anterior neck approach, two CCAs were clipped for 10 min under anesthesia. Aminoguanidine (100 mg/kg) was administered intraperitoneally immediately after 4-VO, and then twice a day for three consecutive days. Cresyl violet staining and immunohistochemical analysis for the expression of GFAP, CD11b, nitrotyrosine, iNOS, and Bax were performed, using brain slices obtained from the rats that were sacrificed 1, 3, 5 and 7 days after reperfusion.
RESULTS
Aminoguanidine reduced neuronal cell death in the CA1 region of the hippocampus. Expression of GFAP, CD11b, nitrotyrosine, iNOS, and Bax were significantly increased in the CA1 region of the hippocampus three days after 4-VO.
CONCLUSIONS
We believe that modified 4-VO is a good method to study transient forebrain ischemia as it is simple and inexpensive to perform and can be utilized without stereotaxis, a pivoting dissection microscope, EEG, a laser flowmeter or the use of Mongolian gerbils.
- Nicotinamide Reduces the Infarct Volume in a Rat Model of Transient Middle Cerebral Artery Occlusion.
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Min Sup Lee, Young Jun Ahn, Ki Young Choi, Gu Kang, Seong Sik Kang, Il Young Cheong, Kun Jai Lee, Keun Woo Kim
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Korean J Pathol. 2006;40(2):93-102.
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Abstract
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- BACKGROUND
Cerebral ischemia depletes ATP and causes irreversible tissue injury. Nicotinamide is a precursor of NAD+ and it is also a poly (ADP-ribose) polymerase (PARP) inhibitor that increases the neuronal ATP concentration and so protects against stroke. Therefore we examined whether nicotinamide could protect against cerebral ischemia by using a model of transient middle cerebral artery occlusion (MCAO) (reperfusion 2 h post ischemia) in Sprague-Dawley rats.
METHODS
Nicotinamide (500 mg/kg) or normal saline was administered intraperitoneally 24 and 0 h before and after MCAO, respectively. The infarction volumes were determined with triphenyltetrazolium chloride staining 24 h after reperfusion. The nitrotyrosine, PAR polymer and PARP-1 expressions were examined by immunohistochemistry with using brain slices obtained from the rats that were sacrificed at 0, 15, 30, 60 and 120 min after reperfusion.
RESULTS
The infarction volumes were significantly attenuated (21.8%, p<0.05). The nitrotyrosine expressions were increased at 0, 15 and 30 min, and those expressions for PARP polymer and PARP-1 were increased at 60 and 120 min, respectively. Nicotinamide partly reduced the expressions for nitrotyrosine and PAR polymer except for PARP-1.
CONCLUSIONS
These results suggest that nicotinamide may attenuate ischemic brain injury through its antioxidant activity and the inhibition of PARP-1.
- Minocycline Attenuates the Development of Allodynia: An Immunohistochemical Study on CD11b, GFAP and c-Fos in the Spinal Dorsal Horn in SD Rat.
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Gu Kang, Ki Young Choi, Min Sup Lee, Young Jun Ahn, Seong Sik Kang, Il Young Cheong, Wanjoo Chun, Sung Soo Kim
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Korean J Pathol. 2004;38(5):311-318.
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Abstract
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- BACKGROUND
Minocycline, a semisynthetic second-generation tetracycline, is an antibiotic that has excellent ability to penetration into the CNS via the brain-blood barrier.
Minocycline has emerged as a potent inhibitor of microglial activation, and it is an effective neuroprotective agent in experimental brain ischemia. Glial cell activation and proliferation are known to be associated with neuropathic pain in the peripheral nerve injuries.
METHODS
The fifty percent threshold of withdrawal responses was measured in the hindpaws of SD rats following tight ligation of left fifth lumbar spinal nerve. Rats were sacrificed at 1, 3, 5, and 7 days and at 0.5, 1, 2, and 4 h post ligation (n=5/group/time point). Immunohistochemistry for GFAP, CD11b and c-Fos was done on the spinal cord at the level of the fifth lumbar nerve. Minocycline (45 mg/kg) and normal saline (300-400 microL) were administered intraperitoneally, 1 day and 1 h before the operations, and every day postoperatively until the rats were sacrificed.
RESULTS
Treatment with minocycline reduced allodynia and the expressions of CD11b at 5 days and c-Fos at 1 and 2 h post operation compared with the saline treatment (control).
CONCLUSIONS: It was thought that minocycline reduced the allodynia induced by tight ligation of the fifth lumbar spinal nerve in rats through the inhibition of microglial activation and c-Fos expression.
- The Expression of Bcl-2, Bax, Cytochrome C and Caspase-3 in Camptothecin-Induced Apoptosis of Mouse 3T3 Fibroblasts.
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Young Jun Ahn, Min Sup Lee, Gu Kang
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Korean J Pathol. 2002;36(2):71-76.
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Abstract
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- BACKGROUND
Camptothecin (CPT), which has been used for cancer treatment and apoptosis as an inhibitor of DNA topoisomerase I. We investigated the possibility that camptothecin induces anti-appoptotic bcl-2 and pro-apoptotic bax, cytochrome c and caspase-3.
METHODS
We performed immunocytochemical stains for bcl-2, bax and cytochrome c, and also performed westem blots for caspase-3 and the three proteins above using mouse 3T3 fibroblasts treated with CPT (0.5 microgram/mL). The immunostain for bcl-2 was done 12 hours after a microinjection of antisense oligomer to bcl-2 in the nuclei of the cells.
RESULTS
On immunocytochemistry, bcl-2 showed no expressions regardless of CPT treatment and microinjection of the antisense oligomer. The expression of cytochrome c was not changed before and after CPT treatment, and bax demonstrated weak or moderate expressions at 36 and 48 hours afte the treatment. There were no expressions at 0, 12, and 24 hours after CPT treatment. On westem blot, bcl-2 exhibited no expressions before and after CPT treatment. Expressions of ctyochrome c and caspase-3 increased after CPT treatment, and expressions of bax decreased 24 hours after CPT treatment followed by a tendency of increased expressions as time went by.
CONCLUSIONS
In the CPT-induced apoptosis of mouse 3T3 fibroblasts, CPT induced increased expressions of bax, cytochrome c and caspase-3 with no expressions of bcl-2, which are associated with the apoptosis pathway.
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