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Biomedical subjects

D K Lee

Publications and source records attributed to D K Lee.

At least 109 records · Page 6Linked to original sources
PubMed1997

Fauna and geographical distribution of house dust mites in Korea.

During the period of 1933-1994, house dusts were collected from 65 homes at 10 different localities by operating electric vacuum cleaners. House dust mites were isolated from 10 g dust by applying the modified wet sieving method. Total 7,257 mites were collected and 23 species were identified. Among them. Dermatophagoides farinae (DF) was predominant (65.3% of the total), followed by D. pteronyssinus (DP) (20.6%) and Tyrophagus putrescentiae (TP) (6.5%). Rhizoglyphus robini. Sancassania phyllophagianus, Cheyletus traussarti and Scheloribates latipes were the first findings from Korea. DF was predominant in Seoul (66.8%). Kwangju (63.6%), inland of Pusan (79.6%), Inchon (96.5%). Taejon (83.9%), Chonju (87.15) and Chongju (95.2%), whereas DP was predominant in Yongkwang-ub (72.5%) and Yongdo (island) of Pusan (64.9%), and TP in Chunchon (38.2%). The localities where DP and TP were predominant showed higher relative humidity in air (> 73% RH). Among 62 study homes, DF, DP and TP were found in 24.6% of the homes, co-habitat of two species in 48.1% and one species in 27.3%. DF was predominant in 63.5% of the homes studied. DP in 29.6% and TP in 6.9%. In 10 g of the house dust, less than 99 mites were found in 49 homes (70.0%), 100-499 mites in 11 homes (15.7%). 500-999 mites in 3 homes (4.3%) and more than 1,000 mites in 2 homes (2.9%). No mite was found in 5 homes (7.1%). In order to evaluate environmental factors affecting the population density of house dust mites, house type, age of house construction, size of the house, number of the family and frequency of the cleaning were compared with the number of mites, and none of the above factors were statistically correlated with the mite density.

Animals↗
PubMed1997

DNA analysis by flow cytometry in early gastric cancer.

OBJECTIVES: Flow cytometric analysis of a paraffin-embedded block of tissue provides rapid and accurate means of analyzing the DNA content of a tumor. The aim of this study was to clarify the clinical significance of flow cytometric findings in early gastric cancer(EGC). Thus we conducted this study to investigate whether DNA contents of tumor cells can correlate with known prognostic indices in patients with EGC. METHODS: The flow cytometric DNA analysis was performed with paraffin-embedded specimens from tumors of 107 patients with EGC. Flow cytometric analysis was performed using a FACScan (Becton Dickinson). In constructing the histogram, 30,000 cells were scanned from each section and results were scored. The S-phase fraction was obtained according to the CellFit cell cycle analysis (Becton Dikinson). Frequencies of aneuploidy in tumors with various clinical and pathologic parameters were compared using the chi-square test. Mean SPF/PI valuse were compared by the student t-test. RESULTS: Diploidy pattern was observed in 80 (75%) cases while aneuploidy was seen in 27(25%) cases. Aneuploidy was more frequently detected in tumors with submucosal involvement (32.7%) and lymph node (+) group (30.8%) than in the mucosal tumor (17.3%) and lymph node (-) group (24.5%), but the differences were not significant. Frequency of aneuploidy was not affected by either the histologic type or morphologic classification. On the other hand, high proliferative activities (SPF/PI) significantly correlated with the submucosal tumor invasion (66.7% vs. 45%; p < 0.05) and lymph node metastasis (28.6% vs. 7.5%; p < 0.05). CONCLUSION: Tumor aggressiveness is not directly related to DNA aneuploidy but proliferative activities are responsible for the aggressive nature of early gastric cancer. The results of this study show that DNA analysis by flow cytometry in considered to be one method of determining the biological activity of gastric cancer cells.

Adult↗
PubMed1996

Activation of the complete mouse metallothionein gene locus in the maternal deciduum.

The mouse metallothionein (MT) gene family consists of four known members (MT-I through IV) clustered on chromosome 8. Studies reported herein examine the expression and regulation of the MT-III and MT-IV genes in specific cell types in the maternal reproductive tract, developing embryo, and fetus known to express the MT-I and -II genes. MT-III and MT-IV mRNAs were absent from the visceral yolk sac, placenta, and fetal liver, tissues with high levels of MT-I and MT-II mRNAs. In contrast, MT-III and MT-IV mRNAs were both abundant in the maternal deciduum, and in experimentally induced deciduoma on 7 and 8 days postcoitum (1 dpc = vaginal plug), as are MT-I and -II mRNAs. The abundance of each of these MT mRNAs increased coordinately during development of the deciduum (6-8 dpc), and in situ hybridization localized MT-I, MT-III, and MT-IV mRNAs to the secondary decidual zone of the antimesometrial region on 8 dpc, where in some regions all of the cells were apparently positive. Thus, all of the known mouse MT genes are co-expressed in at least some of the cells in the secondary decidual zone. Electrophoretic analysis of decidual MT suggested that the MT-I, -II, and -III isoforms are abundant proteins in the secondary deciduum. Bacterial endotoxin-lipopolysaccharide (LPS) and Zn are powerful inducers of MT-I and MT-II gene expression in many adult organs, whereas these agents apparently have little effect on MT-III and MT-IV gene expression. Neither of these agents significantly effected levels of decidual MT-III or MT-IV mRNAs in vivo or in primary cultures of decidual cells in vitro, and only modest effects of Zn on MT-I mRNA levels were noted. During 2 days of in vitro culture, decidual cell MT-I and MT-III mRNA levels remained elevated while MT-IV mRNA levels decreased. Thus, expression of the mouse MT gene locus in the deciduum appears to be developmentally regulated, and in this tissue, the MT genes are refractory to induction by Zn or inflammation.

Animals↗
PubMed1996

Transgenic mouse blastocysts that overexpress metallothionein-I resist cadmium toxicity in vitro.

The role of metallothionein with regard to cadmium toxicity in vitro was investigated using preimplantation mouse blastocysts derived from a transgenic strain that constitutively overexpresses metallothionein-I transgenes (MT-I*). Northern blot and in situ hybridization revealed high levels of MT-I mRNA in transgenic blastocysts when compared with control blastocysts, and reverse transcriptase-polymerase chain reaction-amplified MT-I mRNA was almost exclusively MT-I*. Moreover, pulse-labeling experiments showed that the relative rate of synthesis of MT was 9-fold higher in transgenic blastocysts. Cadmium (Cd2+) toxicity was assessed after incubating blastocysts for 4 hr in Whitten's medium containing 50 microM Cd2+. Embryos that displayed abnormal morphology were judged "sensitive". Transgenic blastocysts were more resistant to cadmium-induced morphological changes than were control blastocysts. "Sensitive" and "resistant" blastocysts were individually genotyped by polymerase chain reaction, or they were transferred to foster mothers, and embryonic development to midterm was monitored. Of the blastocysts derived from mating heterozygous transgenic males with control females, 56% were transgenic before incubation with Cd2+, whereas 95% of the blastocysts that retained normal morphology after incubation were transgenic. Moreover, after Cd2+ exposure, transgenic blastocysts with normal morphology were nine times more likely to develop to midterm than were control blastocysts with normal morphology. Blastocysts with abnormal morphology failed to develop to midterm. These studies indicate that MT plays a central role in protection from Cd2+ toxicity within the physiological context of the developing mouse embryo.

Animals↗
PubMed1996

Differential expression of D-type G1 cyclins during mouse development and liver regeneration in vivo.

D-type G1 cyclins are the primary cell cycle regulators of G1/S transition in eukaryotic cells, and are differentially expressed in a variety of cell lines in vitro. Little is known, however, about the expression patterns of D-type G1 cyclins in normal mouse in vivo. Thus, in the present study, tissue-specific expressions of cyclin D1 and D3 genes were examined in several tissues derived from adult male mice, and stage-specific expression of cyclin genes was studied in brain, liver, and kidney of developing mice from embryonic day 13 to postnatal day 11. Cell cycle-dependent expression of cyclins was also examined in regenerating livers following partial hepatectomy. Our results indicate that (1) cyclins D1 and D3 are expressed in a tissue-specific manner, with cyclin D1 being highly expressed in kidney and D3 in thymus; (2) cyclin D3 mRNA is abundantly expressed in young proliferating tissues and is gradually reduced during development, whereas cyclin D1 mRNA fluctuates during development; and (3) compensatory regeneration of liver induces cyclin D1 gene expression 12 hr after partial hepatectomy, and cyclin D3 gene expression from 36 to 42 hr (at the time of G1/S transition). In conclusion, this study indicates that cyclin D1 and D3 genes are differentially expressed in vivo in a tissue-specific, developmental stage-dependent, and cell cycle-dependent manner.

Animals↗
PubMed1996

Endoscopic mucosectomy using an esophageal variceal ligation device for minute gastric cancer.

We present here a modified technique for endoscopic mucosal resection using the technique of esophageal variceal ligation for minute gastric cancer. This method of endoscopic mucosal resection requires only the commonly-used one-channel endoscope, an esophageal variceal ligation device, and some clinical experience with the ligation of esophageal varices and snare polypectomy. It can therefore be considered technically simple and safe. We treated four patients with minute gastric cancer using this endoscopic mucosal resection technique. All tumors were completely resected without major complications. Resected specimens were 1.0-1.5 cm in diameter, sufficient for histopathological evaluation, and curative resection was achieved in all patients.

Adenocarcinoma↗
PubMed1996

Elevated rates of early discontinuation from pharmacotherapy trials in alcoholics and drug abusers.

The failure of subjects to complete clinical trials is a common problem with important implications for the interpretation of study results. Although a substantial literature exists on the high prevalence of premature termination from psychiatric and substance abuse treatment setting, there has been little attention paid to early discontinuation in clinical trials. There is evidence that the presence of substance abuse predicts higher rates of early discontinuation. This, combined with a recent increase in efforts to develop medications for treatment of substance use disorders, led us to conduct a literature review to determine whether pharmacotherapeutic trials for patients with these disorders have higher rates of premature discontinuation than comparable studies of patients with other psychiatric disorders. Of 267 articles that were initially identified, 83 met predetermined criteria for inclusion in the analysis. As hypothesized, after controlling for a number of potential contributing variables, treatment trials with substance abuse patients showed a significantly poorer retention rate than those of patients with other psychiatric diagnoses. The difference in retention rate was also evident when studies specific to alcohol dependence, the largest subgroup of substance use disorders, were evaluated separately. Although the retrospective nature of the study design limits the conclusions that can be drawn, the results suggest that, in pharmacotherapy trials with alcoholics or other substance abuse patients, particular attention should be paid to enhancing treatment retention.

Alcoholism↗
PubMed1996

Long-term outcome when major complications follow coronary artery bypass graft surgery. Recovery after complicated coronary artery bypass graft surgery.

OBJECTIVE: To determine whether information available 1 week after surgery correlates with long-term function in patients who suffer major complications after coronary artery bypass graft (CABG) surgery. DESIGN: An inception cohort study. SETTING: A 526-bed community teaching hospital. PATIENTS: All 67 patients who required at least 7 days of CT-ICU care following 2,751 consecutive CABG operations. MAIN OUTCOMES: Hospital survival, long-term survival, and functional ability at long-term follow-up. RESULTS: Forty-three patients survived hospitalization (64%), while 24 died 37 +/- 45 days (range, 7 to 190 days) after surgery. When 42 patients were surveyed 22 +/- 9 months after surgery, 21 of the survivors enjoyed excellent, independent function, 7 were moderately impaired but living at home, 6 were institutionalized with severe limitations, and 8 had died. Patients with very severe cardiac or neurologic dysfunction 1 week after surgery had an extremely poor outcome. When mechanical ventilation was required for causes other than primary failure of the respiratory system, long-term function and hospital survival were poor. Twelve of 14 patients with pulmonary complications survived hospitalization, and all 12 were alive at long-term follow-up. CONCLUSION: More than half of patients requiring 7 days or more of ICU treatment after CABG surgery survive, and many enjoy excellent long-term function. However, those with very severe cardiac or neurologic dysfunction 1 week after surgery have little chance for independent recovery.

Activities of Daily Living↗
PubMed1996

Somatotopic localization of thermal stimuli: I. A comparison of within- versus across-dermatomal separation of innocuous thermal stimuli.

Fourteen healthy subjects (4 males, 10 females) were asked to localize a thermal stimulus applied to the left distal forearm. Two temperature-controlled probes (1,2-cm2 area each) were strapped to the forearm, separated by 8 cm. The probes were positioned in one of three ways: (1) longitudinally within the C6 dermatome, (2) longitudinally within the C8 dermatomes, and (3) transversely with one probe within the C6 and one probe within the C8 dermatome. For any given stimulus configuration, cooling stimuli were localized significantly better than warming stimuli. For both warming and cooling, the transdermatomal configuration (transversely separated probes) provided significantly better localization than the intradermatomal configuration (longitudinally separated probes). Thus, the anisotropy that has been described for tactile spatial acuity is also present for thermal localization. These results suggest that cutaneous somatotopic information is integrated similarly for both and thermal stimuli, but differently within versus across dermatomes.

Female↗
PubMed1996

Characterization of endothelin-induced nociception in mice: evidence for a mechanistically distinct analgesic model.

The behavioral response elicited in mice by an i.p. injection of endothelin-1 (ET-1) (0.1 mg/kg) was differentiated from that elicited by standard agents such as acetylcholine (ACh) (5.5 mg/kg) or phenyl-p-quinone (PpQ) (1.25 mg/kg). First, there was lack of two-way "cross-tolerance' between test paradigms. That is, at equieffective doses, a 60-min prior i.p. injection of ET-1 blocked the behavioral response to a subsequent i.p. injection of ET-1 or PpQ, but not of ACh, whereas a 60-min prior injection of ACh or of PpQ had no effect on a subsequent i.p. injection of ACh, PpQ or ET-1. Second, differential antagonism of ET-1-, ACh- or PpQ-induced responses was observed in an examination of 36 test compounds. For example, cyclo-oxygenase inhibitors such as indomethacin and ibuprofen did not block the ET-1-induced response at > 10 times the doses that blocked ACh- or PpQ-induced responses, whereas other compounds (such as certain benzodiazepines) inhibited ET-1-induced, but not ACh- or PpQ-induced, responses. These findings suggest that ET-1 produces a novel nociceptive stimulus, mechanistically distinct from ACh and PpQ. Hence, the ET-1-induced behavioral response in mice serves as a rapid and convenient measure of in vivo endothelin activity. In addition, this test might be a model for clinical pains not adequately treated by present analgesic agents or adequately tested by preclinical antinociceptive screens using ACh or PpQ. As such, it is a potentially valuable model for the identification of novel analgesic and other agents.

Acetylcholine↗
PubMed1995

Crystal structure of a TFIIB-TBP-TATA-element ternary complex.

The crystal structure of the transcription factor IIB (TFIIB)/TATA box-binding protein (TBP)/TATA-element ternary complex is described at 2.7 A resolution. Core TFIIB resembles cyclin A, and recognizes the preformed TBP-DNA complex through protein-protein and protein-DNA interactions. The amino-terminal domain of core TFIIB forms the downstream surface of the ternary complex, where it could fix the transcription start site. The remaining surfaces of TBP and the TFIIB can interact with TBP-associated factors, other class II initiation factors, and transcriptional activators and coactivators.

Adenoviridae↗
PubMed1995

A comparison of antihypertensive effects between two formulations of atenolol: tenolol and tenormin.

BACKGROUND: Atenolol is a cardioselective beta-blocker. Tenolol is a new formulation of atenolol, with bioequivalence to the original atenolol (Tenormin). This study was designed to compare the antihypertensive effects between the two formulations of atenolol, Tenolol and Tenormin. METHODS: Twenty-three patients, with mild to moderate hypertension untreated with any antihypertensive drugs, were recruited. They were randomized to receive two weeks of placebo, four weeks of Tenolol or Tenormin (100 mg once daily) and two weeks of placebo. Then the treatments were crossed over for four more weeks. RESULTS: At two weeks five patients were excluded because their blood pressures (BP) were below 160/90 mmHg. The baseline BPs for the patients receiving Tenormin (162 +/- 18/97 +/- 8 mmHg) and Tenolol (164 +/- 17/97 +/- 9 mmHg) were not distinct. After two weeks of treatment with Tenormin or Tenolol, systolic BPs decreased by 12 +/- 11 mmHg and 13 +/- 14 mmHg, respectively (p < 0.01 for both formulations). Similarly the diastolic BPs decreased significantly (p < 0.01) by 7 +/- 9 mmHg and 7 +/- 10 mmHg, respectively. The hypotensive effects persisted at four weeks of treatment for both formulations. Reductions in systolic and diastolic BPs by treatment with Tenormin and Tenolol were not significantly different by two-way ANOVA analysis. There were no side effects in any patient throughout the study. CONCLUSIONS: The results indicate that the generic formulation of atenolol (Tenolol) has comparable antihypertensive effects as the original formulation (Tenormin).

Adult↗