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Biomedical subjects

Y C Kim

Publications and source records attributed to Y C Kim.

At least 145 records · Page 8Linked to original sources
PubMed1999

Calcium influx and activation of calpain I mediate acute reactive gliosis in injured spinal cord.

Buffering extracellular pH at the site of a spinal cord crush-injury may stimulate axonal regeneration in rats (1; Guth et al., Exp. Neurol. 88: 44-55, 1985). We demonstrated in cultured astrocytes that acidic pH initiates a rapid increase in immunoreactivity for GFAP (GFAP-IR), a hallmark of reactive gliosis (2; Oh et al., Glia 13: 319-322, 1995). We extended these studies by investigating the effects of certain treatments on reactive gliosis developing in situ in a rat spinal cord injury model. A significant reactive gliosis was observed within 2 days of cord lesion in untreated crush or vehicle-treated, crush control animals as evidenced by increased GFAP-IR and hypertrophy of astrocytes. By contrast, infusion of Pipes buffer (pH 7.4) into the lesion site significantly reduced this increase. The increased GFAP-IR appeared to be linked to Ca2+ influx since infusion of a blocker of L-type calcium channels, nifedipine, reduced the ensuing reactive gliosis significantly. While Ca2+ modulates many signaling pathways within cells, its effect on reactive gliosis appeared to result from an activation of calpain I. Calpain inhibitor I, a selective inhibitor of mu-calpain, also significantly reduced reactive gliosis. However, calpain inhibitor II, a close structural analog which blocks m-calpain, had no salutary effect. We suggest, therefore, that the initial reactive gliosis seen in vivo may result from the activation of a neutral, Ca2+-dependent protease, calpain I, through calcium influx.

Acute Disease↗
PubMed1999

Antioxidative flavonoids from the leaves of Morus alba.

Nine flavonoids (1-9) were isolated from the leaves of Morus alba (Moraceae). The structures of compounds were determined to be kaempferol-3-O-beta-D-glucopyranoside (astragalin, 1) kaempferol-3-O-(6"-O-acetyl)-beta-D-glucopyranoside (2), quercetin-3-O-(6"-O-acetyl)-beta-D-glucopyranoside (3), quercetin-3-O-beta-D-glucopyranoside (4), kaempferol-3-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (5), quercetin-3-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (rutin, 6), quercetin-3-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (7), quercetin-3,7-di-O-beta-D-glucopyranoside (8) and quercetin (9) on the basis of spectroscopic and chemical studies. Compounds 7 and 9 exhibited significant radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl radical.

Antioxidants↗
PubMed1999

Lung cancer and the human gene for ribonucleotide reductase subunit M1 (RRM1).

LOH11A is a region of Chromosome (Chr) 11p15.5 where 75% of lung cancers show loss of heterozygosity (LOH). Clinical and cell biological studies suggest that LOH11A contains a tumor/metastasis suppressor gene. We have mapped this region (650 kb) using overlapping genomic P1/PAC/BAC clones, and one of the genes that we have identified is RRM1. This gene encodes the large subunit (M1) of ribonucleotide reductase, the heterodimeric enzyme that catalyzes the rate-limiting step in deoxyribonucleotide synthesis. By comparing our genomic sequences with the previously published cDNA, we have found that the human gene is composed of 19 exons. It is oriented telomere to centromere and is Alu rich. In order to verify that RRM1 maps within the boundaries of LOH11A, we assessed the frequency of LOH at a SacI polymorphism within intron IX of the gene. We observed LOH in 48% (15/31) of informative lung tumor specimens. To determine whether RRM1 was mutated in tumors, SSCP analysis of the 19 RRM1 exons was performed. No mutations were revealed in 12 pairs of normal and tumor DNA samples. Immunoblots on protein extracts from normal/tumor pairs indicated that a protein of the expected size was present in both. Our conclusion is that RRM1 lies within the LOH11A region, but that its exons are not mutated in tumors. The potential for RRM1 to act as a tumor suppressor is discussed.

Base Sequence↗
PubMed1999

Dowling-Degos disease (reticulate pigmented anomaly of the flexures): a clinical and histopathologic study of 6 cases.

BACKGROUND: Few case series describing Dowling-Degos disease (DDD) have been reported. OBJECTIVE: Our purpose was to review the clinical and histopathologic findings in DDD. METHODS: We reviewed the clinical and histopathologic findings in 6 patients with DDD who were evaluated at the Mayo Clinic. RESULTS: In addition to the typical flexural pigmented reticulate macules, comedo-like lesions on the back or neck or both were present in all 6 patients; 3 patients had pitted perioral scars, and 3 patients reported pruritus of affected flexural areas. Five patients were female, 5 patients had onset of pigmentation before age 24 years, and 3 patients had a family history of DDD. One patient had additional pigmentation involving the dorsum of the hands and proximal nailfolds and fingernail dystrophy. Histopathologically, pigmented rete ridge elongation with thinning of suprapapillary epithelium, dermal melanosis, and perivascular lymphohistiocytic infiltration were consistently observed. CONCLUSION: Comedo-like lesions, pruritus, and pitted perioral scars are common features in association with the reticulate flexural pigmentation. Histopathologically, pigmented rete ridge elongation and dermal melanosis of biopsy specimens from flexural areas are seen.

Adolescent↗
PubMed1999

Sesquiterpene esters from Celastrus orbiculatus and their structure-activity relationship on the modulation of multidrug resistance.

Six new (1-6) and three known (7-9) sesquiterpene esters were isolated from the roots of Celastrus orbiculatus. The structures of the new compounds were elucidated as 1beta-acetoxy-6alpha-furoyloxy-9alpha-benzoyl oxydihydro-beta-agarofur an (1), 1beta-acetoxy-6alpha-benzoyloxy-9alpha-furoyloxydih ydro-beta-agarofur an (2), 1beta-acetoxy-6alpha, 9alpha-difuroyloxydihydro-beta-agarofuran (3), 1beta, 2beta-diacetoxy-6alpha-furoyloxy-9alpha-benzo yloxydihydro-beta-agarof uran (4), 1beta-acetoxy-2beta, 6alpha-difuroyloxy-9alpha-benzoyloxydihydro-beta -agarofuran (5), and 1beta-acetoxy-2beta,6alpha, 9alpha-tribenzoyloxydihydro-beta-agarofuran (6). Compounds 4, 5, and 7-9 were shown to be more active than verapamil in reversing vinblastine resistance in multidrug-resistant KB-V1 cells.

Cell Survival↗
PubMed1999

Testosterone supplementation in the aging male.

World-wide life expectancy at birth for men and women will have increased by about 20 y during 50 y period between 1950 and 2000. As a result, the proportion of the elderly population is expected to increase significantly in the 21st century. Despite this increase in longevity for men and women, men still have significantly shorter life expectancy of approximately 5 y. To further reduce and prevent debilitating disease and disability in elderly men, a question is whether any type of interventions, such as hormone replacement therapy, may play a role in improving the quality of life as proven in post-menopausal women. Men experience age-related decline of capability physically and mentally. Various symptoms, such as nervousness, depression, impaired memory, inability to concentrate, easy fatigability, insomnia, hot flushes, periodic sweating, reduction of muscle mass and power, bone ache, and sexual dysfunction, are related to this change. The fact that a number of age-related changes resemble features of various hormonal deficiency has led to worldwide interest in the use of various hormonal preparations in an effort to prevent the aging process in elderly men. Even though there have been opinions against hormonal supplementation in the aging male, preliminary studies defining the risk/benefit ratio of androgen supplementation appear to be encouraging. To understand testosterone supplementation in the aging male, this review will discuss the following important topics: physiology of male hormonal balance, changes in reproductive organs in elderly men, endocrine evaluation of the male, pharmacological effects of testosterone on target organs, available preparations for testosterone, and testosterone supplementation.

Aging↗
PubMed1999

Treatment of atrophic facial scars with combined use of high-energy pulsed CO2 laser and Er:YAG laser: a practical guide of the laser techniques for the Er:YAG laser.

BACKGROUND: Although CO2 laser resurfacing provides substantial clinical improvement for atrophic facial scars, the CO2 laser often results in excessive thermal damage to the skin. It increases complications postoperatively. The Er:YAG laser ablates thinner layers of tissue than the CO2 laser with minimal thermal damage to the surrounding skin. OBJECTIVE: To determine the efficacy of combined treatment of atrophic facial scars with high-energy pulsed CO2 laser and Er:YAG laser. METHODS: One hundred fifty-eight patients were treated with a combination of high-energy pulsed CO2 laser and Er:YAG laser for atrophic facial scars. All patients were evaluated after 3 months of treatment. RESULTS: The scars improved 80-89% in 65 patients, 70-79% in 56 patients, more than 90% in 32 patients, 60-69% in 2 patients, and less than 60% in 3 patients after laser treatment. CONCLUSION: Treatment of atrophic facial scars with combined use of high-energy pulsed CO2 laser and Er:YAG laser is a very effective and useful method.

Adult↗
PubMed1999

Protopine from Corydalis ternata has anticholinesterase and antiamnesic activities.

While screening extracts of natural products in search of anticholinesterase activity, we found that a total methanolic extract of the tuber of Corydalis ternata (Papaveraceae) showed significant inhibitory effects on acetylcholinesterase. Further fractionation of this extract using acetylcholinesterase inhibition as the parameter screened resulted in the isolation and purification of an alkaloid, protopine. Protopine inhibited acetylcholinesterase activity in a dose-dependent manner. The concentration required for 50% inhibition was 50 microM. The anti-acetylcholinesterase activity of protopine was specific reversible and competitive in manner. Furthermore, when mice were pretreated with protopine, the alkaloid significantly alleviated scopolamine-induced memory impairment. In fact, protopine had an efficacy almost identical to that of velnacrine, a tacrine derivative developed by a major drug manufacturer to treat Alzheimer's disease, at an identical therapeutic concentration. We suggest, therefore, that protopine has both anti-acetylcholinesterase and antiamnesic properties that may ultimately hold significant therapeutic value in alleviating certain memory impairments observed in dementia.

Alkaloids↗
PubMed1999

Scopoletin: an inducible nitric oxide synthesis inhibitory active constituent from Artemisia feddei.

Bioassay-guided fractionation of an H2O extract of Artemisia feddei has furnished an inducible nitric oxide synthase (iNOS) inhibitory coumarin, scopoletin (1) and one of the inactive sesquiterpenes, achillin (2). Compound 1 showed inhibition of nitric oxide (NO) synthesis in a dose-dependent manner in murine macrophage-like RAW 264.7 cells stimulated with interferon-gamma (IFN-gamma) plus lipopolysaccharide (LPS). The inhibition of NO synthesis of 1 was due to suppression of iNOS mRNA and iNOS protein, as determined by Northern and Western blotting, respectively.

Animals↗
PubMed1999

In vitro inducible nitric oxide synthesis inhibitory active constituents from Fraxinus rhynchophylla.

Bioassay-guided fractionation of an H2O extract of the barks of Fraxinus rhynchophylla has furnished two inducible nitric oxide synthase (iNOS) inhibitory compounds, ferulaldehyde (1) and scopoletin (3) together with a coumarin, fraxidin (2). Compounds 1 and 3 showed inhibition of nitric oxide (NO) synthesis in a dose-dependent manner by murine macrophage-like RAW 264.7 cells stimulated with interferon-gamma (IFN-gamma) plus lipopolysaccharide (LPS). The inhibition of NO synthesis of 1 was reflected in the decreased amount of iNOS protein, as determined by Western blotting.

Acrolein↗
PubMed1999

Detection of cancer in augmented breasts by positron emission tomography.

OBJECTIVE: To assess the diagnostic efficiency of positron emission tomography with 18-fluorine fluorodeoxyglucose in detecting breast cancer in augmented breasts. DESIGN: Retrospective study. SETTING: University hospital, Korea. SUBJECT: 9 cases or 8 patients with breasts augmented with paraffin or silicone. INTERVENTION: FDG-PET, mammography, and ultrasonography RESULTS: The mammogram detected the breast cancer in only 1 of 3 patients, and ultrasonography gave a false positive result in 1 patient with an augmented breast. In contrast, PET predicted all the cancers and 5/6 benign lesions. 2/3 breast cancers had axillary FDG uptake interpreted as showing metastatic involvement, and in 1 case with cancer with no axillary lymph node involvement there was no FDG uptake in the axilla, which correlated with the pathological finding. CONCLUSIONS: Although the high cost of PET makes its use as a screening test for all patients with augmented breasts unrealistic, it would be the best diagnostic choice if other methods failed.

Axilla↗
PubMed1999

Paroxysmal tachycardia and hypertension with or without ventricular fibrillation during laparoscopic adrenalectomy: two case reports in patients with noncatecholamine-secreting adrenocortical adenomas.

We present two cases of sudden unanticipated cardiovascular complications in patients with noncatecholamine-secreting adrenocortical adenomas during laparoscopic adrenalectomy. In the first case, the patient developed paroxysmal tachycardia and hypertension followed by ventricular fibrillation shortly after clipping of the adrenal vein. In the second case, the patient suffered hypertension and bigeminy during manipulation of the adrenal gland just around the adrenal vein. Awareness of such complications during either conventional or laparoscopic adrenalectomy is important even if the operation is performed in a patient with an apparently noncatecholamine-secreting adrenocortical adenoma.

Adenoma↗
PubMed1999

Effect of plant matrix and fluid ethanol concentration on supercritical fluid extraction efficiency of schisandrin derivatives.

An investigation of the effect of plant matrix on the supercritical fluid extraction efficiency of five schisandrin derivatives is reported, exhibiting a great difference with respect to extraction efficiency depending on the matrix. Pure supercritical CO2 at 60 degrees C and 34.0 MPa cannot fully recover schisandrin derivatives from the leaves as much as from the other matrices. Only 36.9% of these compounds are extracted from leaves of Schisandra chinensis by supercritical CO2 in comparison with organic solvent extraction. However, more than 80% of schisandrin derivatives are obtained from both stem and fruit parts. Ethanol addition also shows a different effect depending on plant matrix; that is, CO2 modified with 10% ethanol could enhance the yield of schisandrin derivatives from leaves by four times when compared with that of pure CO2, but it has little effect on both stems and fruits.

Carbon Dioxide↗
PubMed1999

Specific expression of heat shock protein HspA2 in human male germ cells.

In the mouse, the heat shock protein 70-2 (Hsp70-2) has been found to play a critical role in spermatogenesis. The HspA2 gene is the human homologue of the murine Hsp70-2 gene with 91.7% identity in the nucleotide coding sequence. We examined the expression of HspA2 in human tissues. To detect HspA2 expression, antiserum 2A that was raised against mouse Hsp70-2 and that cross-reacted with human HspA2 protein expressed in Escherichia coli was used. The results of Western blotting indicate that significant HspA2 expression occurs in testes with normal spermatogenesis, whereas only a low amount of HspA2 was expressed in testis with Sertoli cell-only syndrome. Only a small amount of HspA2 was detected in breast, stomach, prostate, colon, liver, ovary, and epididymis. Immunoreactivity to HspA2 was present in spermatocytes and spermatids in the testes with normal spermatogenesis, while immunoreactivity to HspA2 in testis with Sertoli cell-only syndrome was remarkably decreased or inconspicuous over the entire cell. These results demonstrate that the HspA2 protein is highly expressed in human male specific germ cells, suggesting that HspA2 protein may play a specific role during meiosis in human testes as found in the murine model.

Amino Acid Sequence↗
PubMed1999

Adjuvant (cisplatin, etoposide, and 5-fluorouracil) chemotherapy after curative resection of gastric adenocarcinomas involving the esophagogastric junction.

Gastric adenocarcinomas involving the esophagogastric junction represent a particular therapeutic problem because they lie in the border area between two body cavities: the thorax and the abdomen. The prognosis of gastric adenocarcinomas involving esophagogastric junction is poor because there is widespread lymphatic metastasis, making curative resection difficult. Even in patients with localized disease who are potentially curable, the 5-year survival rate is approximately 20% with curative resection only, somewhat lower than for those with cancer elsewhere in the stomach. The authors conducted a pilot study to evaluate the safety and possible efficacy of adjuvant chemotherapy with cisplatin, etoposide, and 5-fluorouracil (PEF) after curative resection of gastric adenocarcinoma involving esophagogastric junction. Three cycles of adjuvant PEF chemotherapy with cisplatin (20 mg/m2/day intravenously on days 1-5), etoposide (100 mg/m2/day intravenously on days 1, 3, and 5), and 5-fluorouracil (800 mg/m2/day continuous intravenous infusion on days 1-5) were given every 3 weeks after curative resection of gastric adenocarcinoma involving the esophagogastric junction. Between November 1989 and June 1995, a total of 50 patients with postoperative stage II, IIIA, or IIIB disease entered this trial. In 14 of 50 patients (28%), the disease recurred during the follow-up of 4-83 months (median 26 months). Disease-free survival was 4-83+ months (median 48 months), and the actuarial 5-year disease-free survival rate was 48% (95% CI: 41% to 55%). Overall survival was 4-83+ months (median 62 months), and the actuarial 5-year survival rate was 54% (95% CI: 40% to 68%). The prognostic factor analysis showed that the postoperative N stage and the interval between surgery and chemotherapy affected disease-free survival and overall survival. The toxicities of PEF adjuvant chemotherapy were leukopenia, nausea/vomiting, and alopecia, but they were mostly mild and reversible except in one patient who died because of treatment-related sepsis. Adjuvant chemotherapy with three cycles of PEF regimen was well tolerated and seems to be a promising treatment for gastric adenocarcinoma involving the esophagopstric junction, in comparison with previous treatments. To define the efficacy of adjuvant PEF chemotherapy for gastric adenocarcinoma involving esophagogastric junction, prospective randomized trials are warranted.

Adenocarcinoma↗
PubMed1999

Dipyridamole modulated Tc-99m sestamibi lung SPECT in small cell lung cancer.

PURPOSE: In this study, the authors wanted to determine whether dipyridamole-modulated MIBI (dipyridamole-MIBI) could enhance the prediction of the response to chemotherapy in patients with small cell lung cancer. METHODS: Twenty-seven patients with biopsy-proved small cell lung cancer (25 men, 2 women; mean age, 61 +/- 7 years) underwent dipyridamole-MIBI SPECT 3 to 7 days before starting chemotherapy (80 mg/m2 etoposide and 80 mg/m2 cisplatin every 3 or 4 weeks for at least two cycles). Tomographic images before and after dipyridamole (0.84 mg/kg) were acquired 1 hour after injection of 370 (10 mCi) and 1,110 (30 mCi) MBq MIBI, respectively. The response to chemotherapy was grouped as specified as complete response (CR), partial (PR), no change (NC), or progressive disease (PD), according to the change in tumor size on chest roentgenography and CT. Patients showing CR and PR were classified as responders, and those who showed NC and PD were considered nonresponders. RESULTS: Among the 27 patients, 22 were responders (3 CR, 19 PR) and 5 were nonresponders (3 NC, 2 PD). The tumor-to-normal lung ratio (T:NL) of responders was significantly higher than that of nonresponders. The diagnostic accuracy of the T:NL ratio to differentiate responders and nonresponders was 33.3%, with a cutoff value of 2.5, which was significantly improved to 77.8% when an increased T:NL ratio after dipyridamole was assigned to a nonresponder. Furthermore, all patients with CR showed diminished T:NL ratios after dipyridamole, and all patients with NR showed an increased T:NL ratio after dipyridamole. CONCLUSION: Dipyridamole-MIBI SPECT could enhance the prediction of response to chemotherapy in patients with small cell lung cancer.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1999

Postoperative pelvic lymphocele: treatment with simple percutaneous catheter drainage.

PURPOSE: To evaluate the effectiveness of simple percutaneous catheter drainage in the treatment of postoperative lymphocele. MATERIALS AND METHODS: Percutaneous catheter drainage of 23 symptomatic lymphoceles was performed with ultrasonographic (US) guidance in 20 patients who had undergone radical pelvic lymphadenectomy because of uterine malignancy. All lymphoceles were diagnosed on the basis of biochemical and cytologic findings in aspirated fluid. The drainage catheter was removed when the amount of daily drainage was less than 10 mL per day and when the lymphocele was seen at imaging to have resolved. Follow-up US was performed at 1, 3, and 6 months after catheter removal. The results were classified as success, partial success, or failure. RESULTS: Lymphoceles ranged in size from 5 x 4 x 3 to 25 x 10 x 10 cm. Mean total drainage volume was 2,012 mL (range, 300-17,240 mL). Fluid from 10 lymphoceles (43%) was positive at Gram staining and bacteriologic culture; fluid from 13 (57%) was sterile. Duration of catheter drainage was 3-49 days (mean, 22 days). Twenty (87%) lymphoceles resolved completely; three (13%) recurred. Two recurrent lymphoceles were again treated with percutaneous catheter drainage; the third resolved spontaneously 5 months after catheter removal. Successful treatment was ultimately achieved in all patients. Postprocedural complications occurred in four patients. One had a secondary infection of lymphocele; one, catheter dislodgment; and two, skin infection at the site of catheter insertion. CONCLUSION: Percutaneous catheter drainage is safe and effective for treatment of symptomatic postoperative lymphoceles.

Catheterization↗