Endocrinology and Metabolism

Jung Taek Woo (Woo JT)

8 Articles

A Case of Fuctioning Extraadrenal Paraganglioma Mimicking Acute Coronary Syndrome.: Tae Hee Lee, Yeon Ah Lee, Tae Wook Woo, Gwan Pyo Koh, Cheol Young Park, Jung Taek Woo, Sung Woon Kim, Jin Woo Kim, Young Seol Kim; J Korean Endocr Soc. 2003;18(1):94-99. Published online February 1, 2003

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Abstract PDF: A functioning paraganglioma is a rare catecholamine-producing tumor that arises from the extra-adrenal chromaffin tissue. Recently we experienced a case in which a 42 year-old male patient with a functioning extra-adrenal paraganglioma mimicked an acute coronary syndrome. A functioning extra-adrenal paraganglioma was diagnosed by means of a biochemical study and a radiological imaging study. After stabilizing his blood pressure, using alpha adrenergic blocker, we successfully removed a 6?cm sized paraganglioma from between the aorta and the IVC in the retroperitoneal space.

The Significance of Plasma ADH in Differential Diagnosis of Central Diabetes Insipidus.: Ho Jong Lee, In Myung Yang, Sun Kee Min, Jung Hyun Noh, Cheol Young Park, Seung Joon Oh, Deog Yoon Kim, Jung Taek Woo, Sung Woon Kim, Jin Woo Kim, Young Seol Kim, Young Kil Choi; J Korean Endocr Soc. 2001;16(4-5):438-446. Published online October 1, 2001

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Abstract PDF: BACKGROUND
Although the water restriction test(WRT) has been used as a standard test for the differential diagnosis of diabetes insipidus(DI), the measurement of plasma ADH concentration is also known to be useful method for differential diagnosis. Recent studies have shown that some patients with idiopathic central DI(CDI) were found to have a lesion on follow-up imaging studies. There have been no report in Korea on plasma ADH measurement for the differential diagnosis of DI, nor on follow-up imaging study of the idiopathic CDI. METHODS: We retrospectively reviewed the clinical and laboratory findings of 26 patients(12 men, 14 women, age 9-65 years) with CDI, including pituitary MRI or CT scan, who had been diagnosed with WRT and had undergone plasma ADH concentration measurement. RESULTS: 1) Clinical features of the patients with complete CDI did not differ from those of patients with partial CDI. 2) Maximal urine osmolality of complete CDI and partial CDI were 168+/-69mOsm/kg and 431+/-141mOsm/kg, respectively, and the percentage increase in the urinary osmolality after ADH injection was 209+/-149% and 29+/-17%, respectively. 3) Among the 26 patients, 10 patients had their plasma ADH measured. Nine patients in this group were diagnosed as CDI by WRT and plasma ADH concentration of the 9 was compatible for CDI. The plasma ADH level was also inappropriately low in one patient who had been diagnosed with primary polydipsia by WRT, the patient was diagnosed as partial CDI. 4) The findings of follow-up MRI revealed isolated thickening of the pituitary stalk in two cases of idiopathic CDI diagnosed initially with MRI. CONCLUSION: This study suggests that the measurement of plasma ADH can ensure a better differential diagnosis between partial CDI and primary polydipsia, and that the patients with idiopathic CDI should be examined regularly with MRI brain scan, including the pituitary gland.

Analysis of Glucocorticoid Response Element and TPA Response Element of Rat Thyrotropin-Releasing Hormine Gene by Site-Directed Mutagenesis.: Sung Woon Kim, Jin Woo Kim, Young Seol Kim, Young Kil Choi, In Myoung Yang, Jung Taek Woo, Woon Won Chung; J Korean Endocr Soc. 1999;14(2):278-292. Published online January 1, 2001

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Abstract PDF: BACKGROUND
We previously demonstrated that a GRE/TRE composite sequence, which is located between 200 bp and 220 bp relative to the transcriptional start site of rat TRH gene, is responsible for the dexamethasone (DEX)- and TPA-induced transcriptional activation, and the transcriptional activation by DEX is mediated by interaction between glucocorticoid receptor (GR) and a TRE-binding transcriptional factor such as c-Jun. However, a non-specific binding with the transciption factors can not be excluded as the mutants used in the previous report could not inhibit the binding of GR and c-Jun completely, and it remains unclear which one of the two TRE-like sequences is critical for the interaction of the two transcription factors. METHODS: Luciferase expressing plasmids that contain a part of rat TRH promoter including the composite GRE sequence or its mutants were transfected into HeLa cells by Fugene 6. After the cells were incubated overnight with DEX or/and TPA, the luciferase activity was measured in a chemiluminometer. A gel retardation assay was performed after binding of the labeled composite sequence or its mutants with GR and c-Jun. RESULTS: DEX and TPA increased the transcriptional activity of the wild type composite sequence by 3 folds and 4 folds, respectively, and the combined stimulation increased the activity by 10 folds. The mutants of which all 6 nucleotides of the GRE half site were replaced and removed almost did not bind to GR and eould not enhance the transcriptional activity at all in response to DEX. The GRE-deleted mutant bound to c-Jun with a remarkably lower affinity and showed a lower response to TPA, whereas the GRE-replaced mutant bound to c-Jun with a similar affinity and showed a similar response to TPA compared to those of the wild type. In response to the combined simulation with DEX and TPA, the mutants showed 30-40% of the trancriptional activity of the wild type. Basal transcriptional activity of all the TRE mutants was significantly lower than that of the wild type. While they almost could not bind to c-Jun, their binding affinity to GR was comparable to that of the wild type. Whereas the DEX- and TPA-induced transcriptional activity of 5 TRE mutant was 10% and 15% of that of the wild type, it responded to those agents in a similar pattern as the wild type. The 3 TRE mutant and the mutant of both TRE sites did not respond to DEX and TPA. The GRE-deleted mutant hardly formed the DNA-protein complex as did the wild type, while the GRE -replaced mutant could form the complex in a less amount with nuclear extract of HeLa celL CONCLUSION: These results suggest that GRE/TRE composite sequence of rat TRH gene specifically binds to GR and c-Jun, providing a site for interaction between the two transcription factors, and that both TRE sites play an important role in basal transcription, and that the 3 TRE site is more critical in the interaction between GRE and TRE for DEX-induced transcriptional activation. (J Kor Endocrinol 14:278-292, 1999)

The Characterization of Glucocoritcoid Response Element(GRE) on the Promoter of Thyrotropin-Releasing Hormone(TRH) Gene.: Sung Woon Kim, Jin Woo Kim, Young Seol Kim, Young Kil Choi, In Myoung Yang, Jung Taek Woo, Woon Won Chung; J Korean Endocr Soc. 1999;14(2):265-277. Published online January 1, 2001

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Abstract PDF: BACKGROUND
We previously demonstrated that the promoter of rat TRH gene has GRE half site (TGTTCT) between -210 bp and -205 bp flanking with similar sequences of TPA response element (TRE), TAGTCA, at a distance of several base pairs from the GRE half site. It promps us to hypothesize that this composite GRE/TRE sequence can provide a site for interaction between glucocorticoid receptor (GR) and c-Jun. Thus, we investigated whether the composite sequence mediates transcriptional regulation induced by dexamethasone (DEX) and 12-O-tetradecanoyl phobol-13-acetate (TPA), and whether it binds GR and c-Jun. METHODS: A luciferase expressing plasmids that contain a part of rat TRH promoter including the composite sequence or their mutants were transfected into HeLa cells by Fugene 6. After the cells were incubated overnight with DEX and TPA, the luciferase activity was measured in a chemiluminometer. A gel retardation assay was performed after binding of the labeled composite sequence or its mutants with GR and c-Jun. RESULTS: DEX increased the transcriptional activity of the plasmid containing the wild type GRE by 2.5 folds, and TPA increased the transcriptional activity by 4 folds. The simultaneous stimulation with DEX and TPA synergistically increased the transcriptional activity by 10 folds. Two mutants whose GRE half sits were altered showed no responses to DEX, and suppressed the TPA-induced or both agents-induced transcriptional activity by 50%. Two mutants whose TRE-like sites were altered suppressed the DEX-induced transcriptional activity by 20%, TPA-induced trarptional activity by 25%, and both agents-induced transcriptional activity by 50%. Gel retardation assay showed that the composite sequence fonned a complex with GR and its mutants bound to GR with remarkably less affinity. c-Jun also bound to the composite sequence to form two cornplexes with less affinity compared to the AP-1 consensus sequence. The mutants of the TRE-like sequence bound to c-Jun with a significantly lower affinity compared to that of the wild type. Simulateous binding of the composite sequence with GR and c-Jun did not form any larger complex. The complex of GR and the composite sequence was much smaller than that formed by c-Jun, suggesting that GR binds to the composite sequence as a monomer. CONCLUSION: These results suggest that the composite sequence of GRE half site and TRE-like site on the promoter of rat TRH gene provides binding sites for GR and c-Jun, which mediate the interaction between two signal transduction pathways. (J Kor Soc Endocrinol 14:265-277, 1999)

Effect of Isoproterenol on the Glucose-induced Hypothalamin Somatostatin Release.: Sung Woon Kim, Jin Woo Kim, Young Seol Kim, Young Kil Choi, In Myoung Yang, Jung Taek Woo, Chul Young Park, Sun Woo Kim, Jung Hyun Ro, Sang Hwa Kim, Seung Joon Oh, Duk Yoon Kim; J Korean Endocr Soc. 1999;14(2):255-264. Published online January 1, 2001

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Abstract PDF: BACKGROUND
Acute hypoglycemia stimulates somatostatin (SRIH) release from the hypothalamus, and which in turn suppress growth hormone (GH) secretion from the anterior pituitary gland. However, the exact mechanism of glucose increases the hypothalamic SRIH secretion is not well known. Beta-adrenergic pathway is known to stimulate the hypothalamus SRIH release. We, therefore, hypothesized that the glucose-induced SRIH release may be mediated by the stimulation of the central beta-adrenergic system, and investigated to determine whether a beta-adrermgic aganist, isoproterenol, contribute the suppressive effect of glucose on the GHRH-induced GH secretian. METHODS: Ten healthy young men, aged 23 to 26 years, were studied. Four endocrinological tests were carried out. (Test 1) GHRH (Bachem, CA, U.S.A.), 100pg bolus, was given intravenously at 0 minute. (Test 2) Glucose 100 gm dissolved in water, was given orally at -30 minute and GHRH was administered as Test 1. (Test 3) Isoproterenol (Isuprel, Sanofi Winthrop, USA), 0.012 mg/kg, wasinfused continuously between 0 minute and 120 minute, and GHRH was administered as Test 1. (Test 4) Isoproterenol, 0.012 mg kg was infused continuously between 0 minute and 120 minute, and glucose and GHRH were administered as Test 2. RESULTS: Oral glucose ingestion significantly suppressed the GHRH-induced GH secretion. The acute hyperglycemia significantly suppressed GHRH-induced GH secretion. The pretreatments with isoproterenol significantly suppressed the GHRH-induced GH levels. The pretreatment with glucose and isoproterenol suppressed the GHRH-induced GH levels more compared to those induced by glucose in Test 2. The GH levels in Test 4 did not significantly differ from those in Test 3. CONCLUSION: The results of this study suggests that the hypothalamic somatostatinergic activity induced by the oral glucose administeration is not mediated by the beta-adrenergic pathway in normal men. (J Kor Soc Endocrinool 14:255-264, 1999)

Relationship between the Expression of Growth Hormone-Releasing Hormone Receptor Gene and Endocrinologic Profiles in GH-Secreting Pituitary Adenomas.: Sung Woon Kim, Jin Woo Kim, Young Seol Kim, Young Kil Choi, Seung Joon Park, In Myoung Yang, Jung Taek Woo, Mi Sook Ryu, Chul Young Park, Sun Woo Kim; J Korean Endocr Soc. 1999;14(2):241-254. Published online January 1, 2001

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Abstract PDF: BACKGROUND
Growth hormone-releasing hormone (GHRH) plays a key role in the regulation of the proliferation and differentiation of somatomammotroph cells as well as secretion of GH. The actions of GHRH are mediated through the GHRH receptor (GHRH-R) that is a G protein coupled receptor with seven transmembrane domains. It has been demonstrated that alternative splicing occurs in the third cytoplasmic domain of rat and human GHRH-R mRNA, However, the clinical significance of the altemative splicing remains to be unsolved. To find an insight into the clinical significance, we investigate the correlation between the GHRH-R gene expression and a variety of clinical clinical and endocrinological findings in 11 acromegalic patients. METHODS: Eleven acromegalic patients (3 males and 8 females, mean age 43.5 years) were included in this study. Six endocrine tests were carried out to evaluate the GH seeretory function of tumors. Invasiveness of tumors were evaluated by preoperative MRI findings on the basis of Hardys classification. Sequence the gsp oncogene and estimate the GHRH-R gene expression by RT-PCR and in vitro transcription. RESULTS: Three different sized cDNA fragments, 250 bp, 700 bp and 810 bp, were found after RT-PCR. The amount of 250 bp fragment was higher than those of the other two fragments. The clinical findings (age, size, GH level, frequency of paradoxical response to TRH or GnRH, octreotide response, hypothalamic somatostatinergic activity) of the group with high expression of the 250 bp fragment did not significantly differ from those of the group with low expression. The GHRH-R gene expression of tumors with gsp oncogene did not significantly differ from that of tumors without gsp oncogene. CONCLUSION: These results suggest that the expression of GHRH-R gene may not be an important determinant for tumor growth, and the lower GH response to GHRH of tumors with gsp oncogene may not be attributed to the lower expression of GHRH-R gene. The expression of GHRH-R is likely to be regulated by a certain property of tumors for GH secretion and growth.

Gene Expression of Somatostatin Receptor Subtype 2 and 5 in GH-Secreting Pituitary Adenomas.: Sung Woon Kim, Jin Woo Kim, Young Seol Kim, Young Kil Choi, Seung Joon Park, In Myoung Yang, Jung Taek Woo, Kook Ki Kim; J Korean Endocr Soc. 1997;12(4):508-517. Published online January 1, 2001

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Abstract PDF: BACKGROUND
SSTR2 and SSTR5 are most frequently observed in GH-secreting pituitary tumors, and SSTR5 is believed to be more specific to mammosomatotroph lineage. Octreotide binds with high affinity to those two types. There is no report that investigates the quantitative comparison of the two subtype gene expressions, and the correlation between their gene expressions and GH response to octreotide in GH-secreting pituitary adenomas. METHOD: GH response to octreotide was examined in 8 acromegalic patients before transsphenoidal adenomectomy. Genomic DNA and RNA were prepared from fresh frozen tumor tissues. PCR was performed to amplify and sequence the region between codon 184 and 251 that includes exons 8 and 9 of the Gas gene. mRNAs of SSTR2 and SSTRS were quantitated by the comparative RT-PCR and in vitro transcription. RESULTS: The in vitro transcripts of SSTR2 and SSTR5 cDNA were detected in all tumors. The amount of SSTR transcripts was considerably variable between the tumors. The amount of SSTR5 transcript was significantly smaller than that of SSTR2 transcript (0.07+-0.02 vs. 0.87+-0.10), and they did not show any correlation . There was no signicant difference in sex, age, tumor size and grade, basal GH levels, and the GH responses to octreotide between the group with high and low SSTR gene expression. No significant correlation was found between the GH response to octreotide and the amount of SSTR2 transcript, wherease the amount of SSTR5 transcripts showed a tendency of negative correlation with the octreotide response. Tumors with gsp oncogene showed significantly higher response to octreotide than those without the oncogene. The amount of SSTRS transcript in gsp-positive tumors was significantly smaller than in gsp-negative tumors (0.03+-0.01 vs. 0.12+-0.03). CONCLUSION: These results suggest that SSTRS gene expression is lower than that of SSTR2 in GH-secreting adenomas. It is probably attributed to the binding of somatostatin to SSTR5 which has a higher affinity to the hypothalamic somatostatin, Tumors with gsp-oncogene is likely to express a higher density of SSTR5 than those without the oncogene.

Effect of fluoride and vandate on the osteoblast MC3T3-E1 function.: Jung Taek Woo, Hyun Koo Yoon, Young Seol Kim, Sung Woon Kim, In Myung Yang, Jin Woo Kim, Kwang Won Kim, Young Kil Choi, Kwang Sik Seo; J Korean Endocr Soc. 1991;6(2):157-162. Published online January 1, 2001

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Abstract PDF: No abstract available.

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