1.Monoaminergic Activity by Drugs Acting on Adrenergic alpha2-receptors in Rat Hippocampus and Primary Visual Cortex.
Hyung Gun KIM ; Yeung Cheon LEE ; Ki Chung PAIK ; Myung Ho LIM ; Hyun Woo KIM ; Bong Jin KANG
Korean Journal of Psychopharmacology 2004;15(3):371-379
OBJECTIVE: The aim of the this study was to compare the effects of clonidine (a alpha2-adrenoceptor and imidazoline receptor agonist), yohimbine (a selective alpha2-adrenoceptor antagonist) and idazoxan (a alpha2-adrenoceptor and imidazoline receptor antagonist) on extracellular monoamines and their metabolites by using the awakening animal microdialysis and high-performance liquid chromatography with electrochemical detection (HPLC-ECD) in brain regions, which are suggested to have regulatory role in depression. METHODS: We used intracerebral microdialysis in awakening rats by inserting probe through the dorsal hippocampus and occipital cortex especially in primary visual cortex, We studied respective effects of 2.0 mg/kg of clonidine, 5.0 mg/kg of yohimbine, and 5.0 mg/kg of idazoxan on the release of MHPG (a major metabolite of norepinephrine), norepinephrine (NE), DOPAC (a major metabolite of dopamine), and 5-HIAA (a main metabolite of serotonin) by intraperitoneal administration. RESULTS: Clonidine decreased the release of MHPG, NE, DOPAC, and 5-HIAA in both dorsal hippocampus and occipital cortex regions, and there were no significant differences in releasing pattern of all monoamines and their metabolites. Both yohimbine and idazoxan enhanced the release of MHPG, NE, DOPAC, and 5-HIAA in both brain regions, but there were significant differences in releasing pattern of NE and 5-HIAA. Idazoxan induced the delayed and higher efflux of NE and 5-HIAA in the primary visual cortex than yohimbine, but not in the hippocampus. CONCLUSION: This study shows that the selective alpha2-adrenoceptor antagonists increase basal monoamine output and enhance the metabolism of them in the hippocampus and primary visual cortex, and the imidazoline receptor has modulatory role in the regulation of monoamine release in primary visual cortex than hippocampus. It also suggests that high turnover rate of serotonin and norepinephrine in primary visual cortex may contribute to the pathophysiological role in depression.
3,4-Dihydroxyphenylacetic Acid
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Animals
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Brain
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Chromatography, Liquid
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Clonidine
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Depression
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Hippocampus*
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Hydroxyindoleacetic Acid
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Idazoxan
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Metabolism
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Methoxyhydroxyphenylglycol
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Microdialysis
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Norepinephrine
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Rats*
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Serotonin
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Visual Cortex*
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Yohimbine
2.A Multi-institutional Study on Histopathological Characteristics of Surgically Treated Renal Tumors: the Importance of Tumor Size.
Sun Il KIM ; Yeung Deuk CHOI ; Se Joong KIM ; Byung Ha CHUNG ; Do Hwan SEONG ; Chun Il KIM ; Sang Hyeon CHEON ; Jin Seon CHO ; Yun Seob SONG ; Young Sig KIM ; In Rae CHO ; Dong Hyeon LEE ; Ki Hak SONG ; Hong Sup KIM ; Joong Shik LEE ; Won Jae YANG ; Sung Joon HONG
Yonsei Medical Journal 2008;49(4):639-646
PURPOSE: The incidence of accidentally detected small renal tumors is increasing throughout the world. In this multi-institutional study performed in Korea, histopathological characteristics of contemporarily surgically removed renal tumors were reviewed with emphasis on tumor size. MATERIALS and METHODS: Between January 1995 and May 2005, 1,702 patients with a mean age of 55 years underwent surgical treatment at 14 training hospitals in Korea for radiologically suspected malignant renal tumors. Clinicopathological factors and patient survival were analyzed. RESULTS: Of the 1,702 tumors, 91.7% were malignant and 8.3% were benign. The percentage of benign tumors was significantly greater among those < or = 4cm (13.2%) than those > 4cm (4.5%) (p < 0.001). Among renal cell carcinoma patients, the percentage of tumors classed as stage > or = T3 was significantly less among tumors < or = 4cm (5.2%) than those > 4cm (26.8%) (p < 0.001). The percentage of tumors classed as Fuhrman's nuclear grades > or = 3 was also significantly less among tumors < or = 4cm (27.3%) than tumors > 4cm (50.9%) (p < 0.001). The 5-year cancer-specific survival rate was 82.7%, and T stage (p < 0.001), N stage (p < 0.001), M stage (p = 0.025), and Fuhrman's nuclear (p < 0.001) grade were the only independent predictors of cancer-specific survival. CONCLUSION: In renal tumors, small tumor size is prognostic for favorable postsurgical histopathologies such as benign tumors, low T stages, and low Fuhrman's nuclear grades. Our observations are expected to facilitate urologists to adopt function-preserving approach in the planning of surgery for small renal tumors with favorable predicted outcomes.
Adolescent
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Adult
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Aged
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Aged, 80 and over
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Female
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Humans
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Kidney Neoplasms/classification/*pathology/*surgery
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Male
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Middle Aged
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Neoplasm Staging