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Biomedical subjects

Y N Lee

Publications and source records attributed to Y N Lee.

At least 37 records · Page 2Linked to original sources
PubMed1997

Cloning and characterization of two catA genes in Acinetobacter lwoffii K24.

Two novel type I catechol 1,2-dioxygenases inducible on aniline media were isolated from Acinetobacter lwoffii K24. Although the two purified enzymes, CD I1 and CD I2, had similar intradiol cleavage activities, they showed different substrate specificities for catechol analogs, physicochemical properties, and amino acid sequences. Two catA genes, catA1 and catA2, encoding by CD I1 and CD I2, respectively, were isolated from the A. lwoffii K24 genomic library by using colony hybridization and PCR. Two DNA fragments containing the catA1 and catA2 genes were located on separate regions of the chromosome. They contained open reading frames encoding 33.4- and 30.4-kDa proteins. The amino acid sequences of the two proteins matched well with previously determined sequences. Interestingly, further analysis of the two DNA fragments revealed the locations of the catB and catC genes as well. Moreover, the DNA fragment containing catA1 had a cluster of genes in the order catB1-catC1-catA1 while the catB2-catA2-catC2 arrangement was found in the catA2 DNA fragment. These results may provide an explanation of the different substrate specificities and physicochemical properties of CD I1 and CD I2.

Acinetobacter↗
PubMed1996

Taurine intake of Korean breast-fed infants during lactation.

i. Taurine concentrations of human milk of nonvegetarians and lacto-ovovegetarians decreased significantly during the course of lactation. Taurine concentrations in lacto-ovovegetarians after 90 days postpartum were lower than those of nonvegetarians. Taurine concentrations of human milk by 150 days postpartum were: nonvegetarian 248-434 nmol/ml (31.0-54.4 mg/L); lacto-ovovegetarian 153-418 nmol/ml (19.1-52.3 mg/L). ii. Taurine intakes in infants of lacto-ovovegetarians decreased significantly during lactation, unlike from the pattern in infants of nonvegetarians. Taurine intakes in infants of lacto-ovovegetarians at 90, 120 and 150 days postpartum were lower, compared with those in nonvegetarians. Taurine intakes in infants by 150 days postpartum were: Infants of nonvegetarians 169-229 mumol/day (21.1-28.6 mg/day); Infants of lacto-ovovegetarians 106-210 mumol/day (21.1-28.6 mg/day). iii. This study showed that the taurine concentration in human milk and the taurine intake of infants were different during lactation between nonvegetarians and lacto-ovovegetarians, and that the intake per kg body weight decreased during lactation. Results suggest that the differences observed might be due to the effect of consumption of different types of food.

Breast Feeding↗
PubMed1996

In vitro induction of differentiation by ginsenoides in F9 teratocarcinoma cells.

The aim of this study was to determine the ability of the ginsenosides, extracts of Panax ginseng C.A. Meyer, to cause differentiation of F9 teratocarcinoma stem cells as a model system. F9 stem cells cultured in the presence of the ginsenosides together with dibutyryl cyclic AMP (dbcAMP) became parietal endoderm-like cells. Moreover, the expression of differentiation marker genes, such as laminin B1 and type IV collagen, was increased after treatment with the ginsenosides. Among the various purified ginsenosides, Rh1 and Rh2 were the most effective at causing differentiation of F9 cells. Since ginsenosides and glucocorticoid hormone have similar chemical structures, we examined the possibility of the involvement of a glucocorticoid receptor (GR) in the differentiation process induced by the ginsenosides. According to Southwestern blot analysis, a 94 kDa protein regarded as a GR was detected in F9 cells cultured in the medium containing the ginsenosides Rh1 or Rh2. In addition, F9 stem cells treated with the ginsenosides Rh1 or Rh2 and with RU486, a glucocorticoid antagonist with a high affinity for the GR, did not differentiate into endoderm cells morphologically, and the expression of laminin B1 gene was not induced in these cells. In a gel mobility shift assay, protein factors capable of binding to the glucocorticoid responsive element (GRE) specifically were detected in nuclear extracts of the ginsenoside-treated F9 cells. Moreover, overexpression of GR by cotransfection of GR expression vector and GRE-luciferase vector enhanced the transactivation activity of GRE promoter in the presence of ginsenosides Rh1 or Rh2 and was further augmented by dbcAMP. In addition, ginsenosides Rh1 and Rh2 bound to a GR assessed by whole-cell binding assay, even though the specific binding affinity was weaker compared to dexamethasone. Based on these data, we suggest that the ginsenosides Rh1 and Rh2 cause the differentiation of F9 cells and the effects of ginsenosides might be exerted via binding with a GR or its analogous nuclear receptor.

Animals↗
PubMed1995

Prevalence of hepatitis C antibody in patients with chronic liver disease and hepatocellular carcinoma in Korea.

To investigate the contribution of hepatitis C virus (HCV) to chronic liver disease and hepatocellular carcinoma (HCC) in Korea, antibodies to HCV (anti-HCV) were tested by enzyme immunoassay in 1759 patients with chronic liver disease and HCC, and in 808 healthy adults. The prevalence of anti-HCV was 1.6% in 808 controls. Anti-HCV was present in 32 (7.7%) of 418 hepatitis B surface antigen (HBsAg)-positive and 128 (53.1%) of 241 HBsAg-negative patients with chronic hepatitis, 16 (6.0%) of 265 HBsAg-positive and 90 (30.5%) of 295 HBsAg-negative patients with liver cirrhosis, and 16 (4.8%) of 330 HBsAg-positive and 61 (29.0%) of 210 HBsAg-negative patients with HCC. Antibodies to hepatitis B core antigen (anti-HBc) were present in 80-88% of patients who were seropositive for anti-HCV and seronegative for HBsAg. Among the sera from 114 patients with HBsAg-negative and anti-HCV-positive chronic liver diseases, HBV DNA and HCV RNA were detected by polymerase chain reaction (PCR) in 54 (47.4%) and 61 (53.3%), respectively. Both HBV DNA and HCV RNA were detected in 4 (4.4%) samples. The mean age of the patients with both HBsAg and anti-HCV was not different from that of patients who were seropositive for HBsAg alone. These findings indicate that current and/or past HBV infection is still the main cause of chronic liver disease in Korea.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Effects of anisodamine and atropine on the microvasculature of liver, skeletal muscle and foot-pad skin in anesthetized rats].

Rats were urethanised and kept in a constant temperature chamber. The surface temperature of various organs including the liver and the armpit skeletal muscle were monitored with a special mercury thermometer through a narrow hole on the skin cut with scalpel. The temperature of the foot-pad skin were measured using a thermometer as reported previously. After iv of anisodamine or atropine at doses of 12.5-50 micrograms/kg the temperature of the liver and the armpit skeletal muscle were significantly reduced in a dose-dependent manner but the skin temperature was increased. Temperature changes were observed 5 min after drug administration, reaching peak height at about 15 min and maintained for one hour or so. Isoprenaline, dopamine and aminophylline iv showed only a temperature-elevating effect, while serotonin and noradrenaline caused only a temperature-decreasing effect in all the three organs mentioned above. Although the functional significance of the opposite effects on the microcirculation of different tissues remain to be defined, the effects of atropine-like drugs must result in a redistribution of circulating blood and may have beneficial effects on the survival of some vital organs such as brain, lungs, kidneys ... especially in shock.

Animals↗
PubMed1991

Leiomyosarcoma of the broad ligament--report of two cases.

Leiomyosarcoma of the broad ligament (LBL) is a very rare tumor. Up to 1989, there had been only 7 cases reported in the English literature. During recent 12 years, we have had 15 cases of leiomyosarcoma in our department. Among them, there were two cases of LBL. The others were leiomyosarcoma of the uterine corpus. The first patient was 36 years old. She received total abdominal hysterectomy, bilateral salpingo-oophorectomy and paraaortic lymph node sampling followed by chemotherapy with adriamycin. Intra-abdominal recurrence with hepatic metastasis occurred 18 months after operation and she received palliative radiotherapy. The second patient was 65 years old and received subtotal hysterectomy, bilateral salpingo-oophorectomy, omental biopsy and suprapubic cystostomy followed also by chemotherapy with adriamycin. She received segmental resection of ileum and ileostomy due to intestinal obstruction caused by metastasis 5 months after her initial operation. Both patients were still alive when reported with 33 and 26 months of survival, respectively. The nature and management for LBL are scarcely reported, accumulation of cases and clinical experiences are needed.

Adult↗
PubMed1990

Amniotic fluid index measurement with the four-quadrant technique during pregnancy.

Eleven hundred thirty-four pregnant women with reliable dates underwent ultrasound evaluation for amniotic fluid index (AFI) measurement with the modified four-quadrant technique. We found that from 13 weeks' gestation the AFI rose progressively until 26 weeks. From then to 38 weeks the AFI measurements demonstrated little variation. After 38 weeks the AFI appeared to decline gradually. In the third trimester the mean AFI was 16.0 +/- 4.8 cm; 5% of cases had an AFI less than or equal to 8 cm, and 5% had an AFI greater than or equal to 24 cm. These results confirm the reproducibility of the semiquantitative technique and suggest that in estimating amniotic fluid volume, AFI measurement may be a more appropriate means than measurement of the single largest pocket or subjective assessment. Serial AFI measurement would be an effective way of assessing fetal status throughout pregnancy.

Amniotic Fluid↗
PubMed1989

Radical hysterectomy with pelvic lymph node dissection for treatment of cervical cancer: a clinical review of 954 cases.

Nine hundred fifty-four patients, who received a radical hysterectomy and a bilateral pelvic lymphadenectomy, were included in this study which ran from January 1971 to December 1986. The subjects, by in large, ranged in age from 41 to 60. Of these cases, 62.5% were in clinical stage IB, while 26.2% were in stage IIA. Urinary tract fistula formations occurred in 2.4% of the cases and substantially decreased from 6.1% during 1971-1978 to 0.9% in the subsequent period from 1979 to 1986. The operative mortality rate was 0.4%. The follow-up included 438 cases that came from 1971 to 1981, and each was evaluated over a period of 5 years. Of these cases, 28 patients were lost during the follow-up period and were presumed to have died from cancer. The absolute 5-year survival rates for the patients in stage IB, stage IIA, and IIB were 86.1, 71.7, and 60.1%, respectively. The respective 5-year survival rates for patients with stage IB LN(-) and LN(+), i.e., without or with lymph node metastasis, were 87.7 and 73.1%. The survival rates for patients with stage IIA LN(-) and LN(+) were 79.8 and 40.9%, respectively. In retrospect, the 5-year survival rates seem to be related to age, parametrial involvement, and histological type. This study shows that because of improving surgical techniques and anesthesia, acceptable operative morbidity and mortality, as well as favorable 5-year survival rates, radical surgery seems to be the treatment of choice for patients with early invasive uterine cervical, and especially for younger women.

Adolescent↗
PubMed1989

Maternal serum alpha-fetoprotein screening in Taiwanese women.

From January 1986 to August 1988, a maternal serum alpha-fetoprotein (MSAFP) screening program was performed at Mackay Memorial Hospital. Clinical Assay Gamma Dab [I125] AFP RIA Kit (Baxter U.S.A.) was used for the quantitative measurement of AFP in maternal serum. Between 16 and 25 gestational weeks, MSAFP above the cut-off value at 2.5 multiples of the median was able to detect 5/7 cases of anencephalus, 2/4 cases of encephalocele, 3/3, cases of omphalocele, 11/40 cases of twin pregnancies. Among 10 cases with autosomal trisomies, 8/10 were less than 0.6 multiples of the median and 4/10 were less than 0.4 multiples of the median.

Adult↗
PubMed1989

Meigs' syndrome--a case report.

Bilateral ovarian fibromas combined with as and hydrothorax is a rare disorder. A case of bilateral ovarian fibromas combined with ascites and hyrothorax is presented. The ascites and hydrothorax disappeared spontaneously after removal of the ovarian tumors.

Aged↗
PubMed1989

Effects of monomeric and polymeric diets on small intestine following massive resection.

Since the introduction of long-term total parental nutrition, it has been possible to raise the survival rate in patients with massive intestinal resection. How to increase the remaining intestinal mucosa hyperplasia in these patients has become the focus of many studies. Early postoperative enteral feeding with exogenous intraluminal nutrition was considered to be one of the most essential factors. The best enteral food pattern, however, is still not conclusive. In this study, we used the animal model of rats with 60% small intestinal resection, giving them different kinds of enteral diets through gastrostomy tubes. The monomeric diet included amino acid, glucose, disaccharide, and triglyceride. The polymeric diet included the usual source of nutrition such as protein, polysaccharide, and fat. The rats were killed three weeks later. Histopathological changes of the remaining bowel and H3 thymidine incorporation to mucosal DNa were measured. We found: (1) hyperplasia of the remaining bowel in the 60% resected rats was definitely increased more than the rats of the sham operation; (2) from the protein content, the DNA content of mucosa cells, the villus height and crypt depth points of view, the polymeric diet fed rats had a better adaptation; (3) on the 21st postoperative day, the DNA synthetic rate was still very high in polymeric diet fed rats, but returned to preoperative levels in rats fed with a monomeric diet. Our conclusion of this study is that a polymeric diet can contribute to a better intestinal mucosa regeneration than a monomeric diet in the rats with massive intestinal resection.

Adaptation, Physiological↗
PubMed1989

Routine pretreatment evaluation in cervical carcinoma.

A review of 573 previously untreated patients with invasive cervical carcinoma was undertaken to determine the significance of the routine pretreatment performance of chest x-ray, intravenous pyelography (IVP), cystoscopy and sigmoidoscopy. Chest x-ray was performed in 570 patients (99.5%), IVP in 514 (89.7%), cystoscopy, 502 (87.6%) and sigmoidoscopy, 496 (86.6%). The overall yield of tumor-related abnormalities demonstrated in chest x-ray, IVP, cystoscopy and sigmoidoscopy was 1.8%, 9.1%. 6.4% and 1.2% respectively. The chest x-ray findings changed the initial clinical stage in 1.3% of cases, IVP in 4.2%, cystoscopy in 4.0% and sigmoidoscopy in 0.6%. There were 5 instances of bladder involvement and 5 of bullous edema of the bladder found in patients originally classified as having stage I or stage II disease. Thus, to omit cystoscopy may not be so safe in patients with stage I and stage II diseases. We suggest that chest x-ray, IVP and cystoscopy should be performed as part of staging in all patients with cervical carcinoma, however, sigmoidoscopy can be reserved for those initially diagnosed to have advanced disease or symptomatic patients.

Carcinoma↗
PubMed1987

Presence of episomal and integrated human papillomavirus DNA sequences in cervical carcinoma.

Thirty surgical samples of squamous cell carcinoma of the cervix obtained from Chinese women were analysed for the presence of human papillomavirus (HPV) types 16 and 18 using Southern blot hybridization procedure. HPV16 was detected in 53% while HPV18 was found in only 6% of the samples analyzed. When compared with other reports, variation in the geographic distribution of these two HPV types in association with cervical carcinoma is noted. Thirty-seven and a half percent of the HPV16-positive samples contained this HPV type in episomal form and an equal number in cellular DNA-integrated form. The simultaneous presence of both episomal and integrated forms was found in the remaining 25% of the positive samples. The two HPV18-positive cases harbored only episomal viral genome and were not superinfected by HPV16. Analysis of the HPV16 integration samples showed that single integration events had probably occurred and some of the viral sequences had been lost on or subsequent to integration.

Carcinoma, Squamous Cell↗
PubMed1986

Adenylate kinase activity in Mycobacterium leprae.

Adenylate kinase (ATP:AMP phosphotransferase, EC 2.7.4.3) was detected in partially purified preparations of cell-free extracts of Mycobacterium leprae. The apparent Km values of M. leprae adenylate kinase for ADP and Mg2+ were 1 X 10(-4) M, respectively. The enzyme was heat-labile: loss of activity by 80% at 45 degrees C and over 90% at 60 degrees C occurred within 5 min. M. leprae adenylate kinase was distinct from armadillo adenylate kinase in respect of affinity for substrate and heat-sensitivity.

Adenylate Kinase↗