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Biomedical subjects

I Kim

Publications and source records attributed to I Kim.

At least 181 records · Page 10Linked to original sources

Adrenal scanning and uptake with 131I-6beta-iodomethyl-nor-cholesterol.

Adrenal scans were obtained in 50 patients with suspected adrenal disease; 131I-19-iodocholesterol was used in 12 and 131I-6-beta-iodomethyl cholesterol (NP-59) in 38 cases (42 scans). The scan diagnosis was correct in 48 patients. Successful images were obtained with 0.5 mCi, or less, of NP-59 instead of the standard dose of 2 mCi, thus reducing radiation dose to the patient and cost of the agent. Satisfactory scans were obtained in 2--3 days in patients with hyperfunctioning adrenals, and in 3--7 days in other groups of patients, when NP-59 was used. With 131I-19-iodocholesterol, however, 5--10 days were required for optimal results in all patients including those with Cushing disease. Adrenal uptake studies were very useful in the evaluation of adrenal function, particularly in differentiating bilateral hyperplasia from normal adrenals.

Adrenal Gland Diseases↗

Specific inhibition of the testicular mitochondrial respiratory chain in vitro by gossypol.

Optically inactive gossypol is an effective male antifertility agent in several mammalian species, while optically active (+)-gossypol has no antifertility effect in the rat and hamster. Recently, it was suggested that the mitochondria of spermatogenic cells may be a subcellular target of gossypol. We are reporting the effects of optically inactive gossypol and (+)-gossypol on the respiratory chain of mitochondria isolated from the testes and liver of rats and hamsters. The mitochondria were incubated with the test compounds and difference spectra were recorded. Complete inhibition of the testicular mitochondrial respiratory chain was observed at a concentration of approximately 75 microM. In contrast, no inhibition of the liver mitochondrial respiratory chain was observed with the test compounds at concentrations as high as 300 microM. These results demonstrate selective inhibition of the testicular mitochondrial respiratory chain by gossypol isomers.

Animals↗

Scrub typhus pneumonitis acquired through the respiratory tract in a laboratory worker.

We report a case of scrub typhus pneumonitis in a laboratory worker who apparently acquired it through the respiratory tract. The patient was suffering from fever, cough and dyspnea. He had both cervical and axillary lymphadenopathy, and hepatomegaly. A chest X-ray showed interstitial infiltrates. A diagnosis of scrub typhus was established upon isolation of Orientia tsutsugamushi. 12 days before the patient showed symptoms, he had purified O. tsutsugamushi proteins from infected cells using an ultrasonication method which could generate aerosols containing O. tsutsugamushi.

Adult↗

Wound epithelialization deficits in the transforming growth factor-alpha knockout mouse.

In vitro, transforming growth factor-alpha is an important factor controlling epithelial cell proliferation and migration. However, the transforming growth factor-alpha knockout mouse has shown no wound epithelialization defect in tail amputation and full-thickness back wounds. To resolve this disparity, we combined a full-thickness head wound and a partial-thickness ear wound on the transforming growth factor-alpha knockout mouse for analysis of wound epithelialization with or without granulation tissue formation. Three-millimeter ear wounds were made on the transforming growth factor-alpha knockout and heterozygous control mice. Full-thickness head wounds were made using a 6-mm trephine on the crown of the skull. In the ear model, transforming growth factor-alpha knockout mice had significantly larger epithelial gaps versus control at post-operative day 3 and 5. Epithelial thickness at the wound edge of transforming growth factor-alpha deficient mice was also depressed at post-operative day 3 and post-operative day 5 compared to control mice. On post-operative day 8, most wounds of both groups were epithelialized. In contrast, no difference in epithelial gap or new granulation tissue was found in the head model. The data support the concept that transforming growth factor-alpha plays a significant early role in wound epithelialization in vivo but its deficit is compensated if accompanied by granulation tissue formation. The data further show the importance of appropriate wound models to address the role of vulnerary factors.

Animals↗

Effects of ethane dimethane sulfonate on the functional structure of the adult rat testis.

In ethane dimethane sulfonate (EDS)-treated adult Sprague Dawley rats, Leydig cells (LC) were not present up to 14 days but seen at 21 days. They increased in number thereafter and reached the values of age-matching controls (i.e., 150-day-old untreated) at day 60. Mesenchymal cell number per testis also increased and reached a peak at day 21, and remained at a higher (p<.05) value than the controls at days 28-60. LC were smaller at day 21, but were larger at days 28-60 (compared to untreated 90- and 150-day-old rats) and secreted more testosterone at day 60 compared to both control groups. Testes of treated rats had greater numbers of macrophages (except at day 28) and they were smaller than those in untreated rats and 60-day EDS rats. Immunolabeling studies on 3beta-HSD, 11beta-HSD1, and LH receptor activity and androgen data agreed with morphological findings. The relationship between mesenchymal and LC numbers during LC differentiation following EDS treatment is reminiscent of this process in prepubertal testis. The presence of increased numbers of macrophages in treated testes agreed with the role of macrophages on LC differentiation. The absence of aging signs in LC of 60-day treated rats who were 150 days of age can be attributed at least in part to their newly differentiated status in older rats (i.e., equivalent to pubertal LC and not to aged LC). Larger LC observed in EDS rats at days 28-60 and their increased testosterone secretory capacity at day 60 (compared to controls) are attributed to elevated plasma LH levels and locally produced factors in EDS rats.

11-beta-Hydroxysteroid Dehydrogenases↗

Small cell osteogenic sarcoma of the ribs: cytological, immunohistochemical, and ultrastructural study with literature review.

Small cell osteosarcoma (OS) is a rare variant of OS that is composed of small cells resembling those of Ewing's sarcoma (ES) with recognizable osteoid. This type of tumor often creates difficulty in making a diagnosis when tissue samples do not include osteoid. The frequent sites are long bones and until now there have been no reported cases arising in the ribs. A case is reported here of small cell OS occurring in the ribs of a 37-year-old female with its aspiration cytologic and electron microscopic characteristics. In the cytologic smear, the small round neoplastic cells were individually scattered or arranged in small nests. The nuclei were hyperchromatic and oval with no visible nucleoli. Ultrastructurally, the nuclei had a round or oval euchromatic chromatin pattern and occasional nucleoli. The scanty cytoplasm contained a small quantity of organelles including either tubular or dilated cisternae of RER, a few mitochondria, and free or polyribosomes. Other organelles were absent. Although the electron microscope sample of this case did not include bone mineral (hydroxy apatite), the electron microscopic features of the tumor cells were unique and useful for exclusion of other small round cell neoplasms.

Adult↗

Reverse transcription-polymerase chain reaction and western blotting analysis for detection of p63 isoforms in uterine cervical cancers.

The aim of this study was to investigate the role of TAp63 and DeltaNp63 isoforms in uterine cervical cancers. The messenger RNA (mRNA) and protein expressions of TA and DeltaN forms as well as alpha, beta, and gamma isoforms of p63 were studied in seven SiHa, ME-180, SNU17, SNU902, SNU1160, SNU703, and SNU1299 human papillomavirus (HPV)-positive uterine cervical squamous cell carcinoma (SCC) cell lines, one HT3 HPV-negative SCC cell line, and one HeLa adenocarcinoma cell line using reverse transcription-polymerase chain reaction (RT-PCR) and western blotting. Fresh nonneoplastic and neoplastic tissues of uterine cervical and endometrial cancers were also studied. RT-PCR for TA and DeltaN form and three isoforms of p63 showed positive bands for both TA and DeltaN forms and for all three isoforms in cervical cancer cell lines but weak band for alpha isoform in HPV-negative HT3 SCC cell line and no band for beta isoform in HeLa adenocarcinoma cell line. RT-PCR for TA and DeltaN and three isoforms of p63 mRNA in tissue samples showed positive bands in almost all samples, except for gamma isoform, the expression was weak or absent in nonneoplastic tissues compared with neoplastic tissues. In western blotting, cancer cell lines and both nonneoplastic and neoplastic tissue samples showed expression of TA and DeltaN, and gamma isoform but beta isoform expression with or without alpha isoform was only found in cancer cell lines and neoplastic tissues. beta isoform, possibly of DeltaNp63, may be considered as an important isoform in uterine cervical squamous cell carcinogenesis.

Biomarkers, Tumor↗

The expression of epidermal growth factor receptor, vascular endothelial growth factor, matrix metalloproteinase-2, and cyclooxygenase-2 in relation to human papilloma viral load and persistence of human papillomavirus after conization with negative margins.

The aim of this study was to investigate the correlations between human papillomavirus (HPV) load and vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR), matrix metalloproteinase-2 (MMP-2), and cyclooxygenase-2 (COX-2), and to identify biomarkers that may predict high-risk HPV clearance or persistence after conization with negative margins. The following samples were analyzed: 77 paraffin-embedded specimens from patients with cervical intraepithelial neoplasia (CIN), including 27 CIN 2 conization specimens and 50 CIN 3 conization specimens. Immunohistochemical analysis was performed with antibodies to VEGF, EGFR, MMP-2, and COX-2. Hybrid capture II testing was used to detect HPV DNA. VEGF expression was significantly associated with HPV load (rho = 0.27186, P = 0.0191), while COX-2 expression was significantly and inversely associated with HPV load (rho = -0.34309, P = 0.0028). In univariate analysis, HPV load (P = 0.0112) and VEGF expression (P = 0.0274) were significantly associated with high-risk HPV clearance or persistence after conization with negative margins. In multiple regression analysis, high viral load (relative light unit/positive control > 500) and positive VEGF expression were significantly associated with high-risk HPV persistence after conization with negative margins (odds ratio [OR]: 9.915, CI: 1.891-51.994; OR: 6.661, CI: 1.208-36.722, respectively). In conclusion, VEGF expression is related to HPV load, while COX-2 expression is inversely related to HPV load, and immunohistochemical analysis of VEGF expression and HPV viral load are a significant and an independent prognostic indicator of high-risk HPV persistence after conization with negative margins.

Adult↗

Angiopoietin-1 regulates endothelial cell survival through the phosphatidylinositol 3'-Kinase/Akt signal transduction pathway.

Angiopoietin-1 (Ang1) is a strong apoptosis survival factor for endothelial cells. In this study, the receptor/second messenger signal transduction pathway for the antiapoptotic effect of Ang1 on human umbilical vein endothelial cells was examined. Pretreatment with soluble Tie2 receptor, but not Tie1 receptor, blocked the Ang1-induced antiapoptotic effect. Ang1 induced phosphorylation of Tie2 and the p85 subunit of phosphatidylinositol 3'-kinase (PI 3'-kinase) and increased PI 3'-kinase activity in a dose-dependent manner. The PI 3'-kinase-specific inhibitors wortmannin and LY294002 blocked the Ang1-induced antiapoptotic effect. Ang1 induced phosphorylation of the serine-threonine kinase Akt at Ser473 in a PI 3'-kinase-dependent manner. Expression of a dominant-negative form of Akt reversed the Ang1-induced antiapoptotic effect. Ang1 mRNA and protein were present in vascular smooth muscle cells but not in endothelial cells. Cultured vascular smooth muscle cells, but not human umbilical vein endothelial cells, secreted Ang1. These findings indicate that the Tie2 receptor, PI 3'-kinase, and Akt are crucial elements in the signal transduction pathway leading to endothelial cell survival induced by the paracrine activity of Ang1.

Angiopoietin-1↗

Regulation of the expression of HMG1, a co-activator of the estrogen receptor.

HMG1 is a protein of high clinical significance. Besides shielding of DNA adducts against repair enzymes making cells more sensitive to cisplatin therapy, it is also a co-modulator of the activity of steroid hormone-regulated genes. Although HMG1 is regulated by various factors, including steroid hormone estrogen, nothing was known about regulatory sequences. Also the sequence of parts of HMG1 including its promoter remains still unknown. We have completed the genomic organization of human HMG1 and characterized its regulatory region by luciferase assay for promoter activity. Insights into the regulation of HMG1 expression are given by the promoter analysis showing a strong functional promoter, enhancing and negative regulatory regions together with a CpG island in intron 1 and several transcription factor binding sites. Furthermore, the finding of two estrogen responsive elements within intron 1 is relevant as they indicate a direct mechanism of HMG1 up-regulation by estrogen making the presence of an estrogen receptor a significant marker for a combined treatment of special tumor types with estrogen and the anticancer drugs cisplatin or carboplatin.

5' Untranslated Regions↗