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Biomedical subjects

C W Lee

Publications and source records attributed to C W Lee.

At least 109 records · Page 6Linked to original sources
PubMed2000

An extract of cultured A431 cells contains major tissue antigens of autoimmune bullous diseases.

BACKGROUND: Autoantibodies that are characteristic of autoimmune bullous diseases (AIBDs) can be detected by immunoblot assay using epidermal or dermal extracts. However, none of the substrates obtained by ordinary methods seems to contain a sufficient amount of all of the autoantigens involved in AIBDs, and diagnosis may require the use of several different substrates. OBJECTIVES: To examine the potential of A431 cell extracts as a substrate for immunoblotting. METHODS: Fourteen sera obtained from patients with major AIBDs (pemphigus vulgaris, pemphigus foliaceus, paraneoplastic pemphigus, bullous pemphigoid and epidermolysis bullosa acquisita) were tested using this substrate. RESULTS: Bands corresponding to desmoglein 1 and 3, desmoplakin 1 and 2, periplakin, BPAG1, BPAG2 and type VII collagen were identified distinctly with these sera. CONCLUSIONS: This finding suggests that culture extracts of A431 cells provide an effective substrate for the diagnosis and differential diagnosis of major AIBDs.

Adult↗
PubMed2000

Cardiovascular manifestations of pheochromocytoma.

Pheochromocytomas are rare tumors that originate in chromaffin tissue and produce their distant variant effects by secretion of catecholamines, tending to mislead the emergency physicians to a wrong diagnosis. Therefore, we analyze the clinical cardiovascular manifestations in patients with pheochromocytoma to improve the diagnostic ability of the emergency physicians. All patients presenting to the Chang Gung Memorial Hospital between January 1993 and December 1997 with a final diagnosis of pheochromocytoma had their charts reviewed. The data of 25 patients including age, sex, adrenergic stimulation presentations, electrocardiographic changes, location of the tumor, and complications were analyzed. Hypertension was the most important major manifestation and fluctuation of blood pressure drew our attention to the possibility of pheochromocytoma. Six patients had abnormal electrocardiographic ST-T segment changes. Five of them had chest pain which prompted them to undergo coronary angiography before surgery, because acute coronary syndrome (unstable angina and acute myocardial infarction) was suspected initially. However, all of them turned out to have normal coronary arteries. Right-sided pheochromocytoma was found in three of these five patients. We should maintain high index of suspicion for pheochromocytoma in patients presenting with chest pain, fluctuating blood pressure, and ischemic electrocardiogram (ECG) changes despite any typical isoenzyme changes. Pheochromocytoma should also be included in the differential diagnosis of acute coronary syndrome because acute catecholamine secretion may induce chest pain and abnormal ECG changes mimicking an ischemic episode. The right-sided pheochromocytoma may present more striking electrocardiographic abnormalities and clinical manifestations.

Adolescent↗
PubMed2000

Randomized comparison of coronary stenting with optimal balloon angioplasty for treatment of lesions in small coronary arteries.

AIMS: Angioplasty of lesions in small coronary arteries remains a significant problem because of the increased risk of restenosis. The aim of this study was to compare the efficacy of elective coronary stent placement and optimal balloon angioplasty in small vessel disease. METHODS: One hundred and twenty patients with lesions in small coronary arteries (de novo, non-ostial lesion and reference diameter <3 mm) were randomly assigned to either balloon angioplasty or elective stent placement (7-cell NIR stent). The primary end-point was restenosis at 6 months follow-up. Optimal balloon angioplasty was defined as diameter stenosis less than or = 30% and the absence of major dissection after the angioplasty, and crossover to stenting was allowed. RESULTS: Baseline clinical and angiographic characteristics were similar in the two groups. Procedure was successful in all patients, and in-hospital events did not occur in any patient. However, 12 patients in the angioplasty group were stented because of suboptimal results or major dissection. Postprocedural lumen diameter was significantly larger in the stent group than in the angioplasty group (2.44 +/- 0.36 mm vs 2.14 +/- 0.36, P<0.05, respectively), but late loss was greater in the stent group (1.12 +/- 0.67 mm vs 0.63 +/- 0.48, P<0.01, respectively). The angiographic restenosis rate was 30.9% in the angioplasty group, and 35.7% in the stent group (P = ns). Clinical follow-up was available in all patients (15.9 +/- 5.7 months) and clinical events during the follow-up were similar in both groups. CONCLUSIONS: These results suggest that optimal balloon angioplasty with provisional stenting may be a reasonable approach for treatment of lesions in small coronary arteries.

Adult↗
PubMed2000

Intravascular ultrasound findings of negative arterial remodeling at sites of focal coronary spasm in patients with vasospastic angina.

BACKGROUND: There are few data about the intravascular ultrasound (IVUS) findings in patients with vasospastic angina, especially regarding patterns of vascular remodeling. METHODS AND RESULTS: Coronary spasm was documented by angiography and electrocardiographic evidence of ischemia in 36 patients after administration of ergonovine (cumulative doses up to 350 microg). After relief of spasm with 1000 microg of intracoronary nitroglycerin, quantitative angiography and IVUS imaging were performed and analyzed by standard methods. The 36 focal spasm sites were compared with the proximal and distal reference segments. The angiographic baseline minimum lumen diameter measured 1.78 +/- 0.66 mm, which decreased to 0.66 +/- 0.38 mm with ergonovine provocation (P <.0001), increased to 2.66 +/- 0.64 mm after intracoronary nitroglycerin (P <.0001 compared with baseline and after ergonovine), and did not change after IVUS imaging (2.66 +/- 0.63, P =.9). By IVUS, atherosclerotic lesions were observed at all coronary spasm sites; the mean plaque burden measured 56% at the spasm site and 35% at the reference. Spasm site plaque composition was hypoechoic in 31 and hyperechoic, noncalcific in 5; there was no calcium. The mean eccentricity index (maximum divided by minimum plaque thickness) was 6.7. Positive remodeling (spasm site arterial area greater than proximal reference) was present in 5; intermediate remodeling (proximal reference greater than spasm site greater than distal reference arterial area) was present in 7; and negative remodeling (spasm site arterial area less than distal reference) was present in 24. CONCLUSIONS: Sites of vasospasm in patients with variant angina showed characteristics of early atherosclerosis, except for an unusually high incidence of negative arterial remodeling.

Adult↗
PubMed2000

Prediction of dioxin/furan incinerator emissions using low-molecular-weight volatile products of incomplete combustion.

Emissions of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/Fs) from incinerators and other stationary combustion sources are of environmental concern because of the toxicity of certain PCDD/F congeners. Measurement of trace levels of PCDDs/Fs in combustor emissions is not a trivial matter. Development of one or more simple, easy-to-measure, reliable indicators of stack PCDD/F concentrations not only would enable incinerator operators to economically optimize system performance with respect to PCDD/F emissions, but could also provide a potential technique for demonstrating compliance status on a more frequent basis. This paper focuses on one approach to empirically estimate PCDD/F emissions using easy-to-measure volatile organic C2 chlorinated alkene precursors coupled with flue gas cleaning parameters. Three data sets from pilot-scale incineration experiments were examined for correlations between C2 chlorinated alkenes and PCDDs/Fs. Each data set contained one or more C2 chloroalkenes that were able to account for a statistically significant fraction of the variance in PCDD/F emissions. Variations in the vinyl chloride concentrations were able to account for the variations in the PCDD/F concentrations strongly in two of the three data sets and weakly in one of the data sets.

Air Pollution↗
PubMed2000

Acquired vulvar smooth muscle hamartoma: a case report and review of the literature.

A 36-year-old Korean woman had had a flesh-colored, indurated plaque with pruritus on the labium majora for five years. The lesion was not found in association with hyperpigmented or hypertrichotic patches. Results of biopsy specimens showed an excess of haphazardly oriented smooth-muscle bundles in the mid to lower dermis with an unremarkable overlying epidermis. Our diagnosis was an acquired smooth-muscle hamartoma in the vulva. Although there have been previously reported cases of acquired smooth-muscle hamartoma, this was the first reported case in the vulva. We also describe the characteristics differing between our case and the six previously reported ones.

Adult↗
PubMed2000

Detection of mycobacterial DNA in cervical granulomatous lymphadenopathy from formalin-fixed, paraffin-embedded tissue by PCR.

Cervical tuberculous lymphadenitis is the most common form of inflammatory neck mass in Korea. The diagnosis of tuberculosis requires proof of the presence of Mycobacterium tuberculosis by acid-fast staining or bacterial growth in culture. However, these are often difficult in cervical tuberculous lymphadenitis. The aim of this study was to investigate the value of the polymerase chain reaction (PCR) technique for detection of mycobacteria in routinely processed tissue sections of cervical granulomatous lymphadenopathy. In this retrospective study, twenty formalin-fixed, paraffin-embedded biopsy specimens from clinically and/or histopathologically diagnosed cervical granulomatous lymphadenopathy were analyzed for mycobacterial DNA by PCR. Two different primers to amplify mycobacterial-common 383-base pair (bp) DNA and Mycobacterium tuberculosis-complex-specific 123-bp DNA were used. Positive PCR products were sequenced directly. Mycobacterial-common DNA (383-bp positive) was found in 10 of the 20 cases. Among them, 7 cases were PCR positive with both primer sets. These seven cases can be considered as tuberculosis. The other three cases indicated possible atypical mycobacteriosis. PCR is a useful technique for the demonstration of mycobacterial DNA fragments in patients with clinically suspected cervical tuberculous lymphadenitis who have acid fast-negative histology and/or unsuccessful mycobacterial cultures.

Base Sequence↗
PubMed2000

Functional interaction between nucleosome assembly proteins and p300/CREB-binding protein family coactivators.

The p300/CREB-binding protein (CBP) family of proteins consists of coactivators that influence the activity of a wide variety of transcription factors. Although the mechanisms that allow p300/CBP proteins to achieve transcriptional control are not clear, it is believed that the regulation of chromatin is an important aspect of the process. Here, we describe a new level of p300-dependent control mediated through the functional interaction between p300/CBP and members of the family of nucleosome assembly proteins (NAP), which includes NAP1, NAP2, and TAF1. We find that NAP proteins, which have previously been implicated in the regulation of transcription factor binding to chromatin, augment the activity of different p300 targets, including p53 and E2F, through a process that is likely to involve the physical interaction between p300 and NAP. NAP proteins can form oligomers, and the results show that NAP proteins can bind to both core histones and p300 coactivator proteins, perhaps in a multicomponent ternary complex. We also provide data in support of the idea that histones can influence the interaction between p300 and NAP protein. These results argue that NAP is a functionally important component of the p300 coactivator complex and suggest that NAP may serve as a point of integration between transcriptional coactivators and chromatin.

Adenovirus E2 Proteins↗
PubMed2000

All-trans-retinoic acid attenuates neointima formation with acceleration of reendothelialization in balloon-injured rat aorta.

Retinoic acids may inhibit vascular smooth muscle cell proliferation, but may promote endothelial cell proliferation in cell culture. However, little data are available about the effects of all-trans-retinoic acid (ATRA) on endothelial regeneration and functional recovery in an experimental model of vascular injury. Accordingly, we investigated whether ATRA may attenuate neointima formation and accelerate endothelial regeneration with functional recovery in balloon-injured rat aorta. Twelve-week-old male Sprague-Dawley rats underwent endothelial denudation of the thoracic aorta by balloon injury. Fourteen rats were fed a standard rat pellet diet. Another 14 rats were fed ATRA (1.5 mg/day) for 2 weeks. The animals were killed on day 14 for organ chamber study and morphometric analysis. Rats in the ATRA group had a significantly improved acetylcholine-induced relaxation response than those in control group. However, endothelial independent response was not significantly different between the two groups. The extent of reendothelialization was markedly superior in the ATRA group compared with control group (p<0.05). Furthermore, neointima area and the ratio of neointima to medial area were significantly less in ATRA group than in control group (p<0.05). In conclusion, ATRA may accelerate endothelial regeneration with functional recovery, and attenuate neointima formation in balloon-injured rat aorta.

Acetylcholine↗
PubMed2000

Clinical constellation of annular erythema associated with anti-Ro/La autoantibodies.

Annular erythema (AE) associated with anti-Ro (SSA) and/or La (SSB) autoantibody in patients with Sjögren syndrome (SS) or with SS/systemic lupus erythematosus overlap syndrome (SS/SLE), has recently been described in Orientals, and it may be a counterpart of annular skin lesion of the subacute cutaneous LE seen mostly in Caucasians. The author examined five Korean AE patients in respect to dinical diversity. In this small-sample study, subtle differences appeared between individual cases regarding the serologic features and the diagnoses of the disease. Among the five cases, four had circulating anti-Ro and anti-La antibodies, and one had only anti-La. Regarding the diagnosis, one was SS/SLE, two were primary SS, and the remaining two were only "AE associated with anti-Ro/La antibody". There seem to be a wide clinical spectrum in the disease expression of AE associated with anti-Ro/La autoantibody than previously thought.

Adolescent↗
PubMed2000

Mutational alterations of the p16CDKN2A tumor suppressor gene have low incidence in mesenchymal chondrosarcoma.

Mutational inactivation of the cyclin-dependent kinase inhibitors (CDKIs) (p16INK4A/MTS1) tumor suppressor gene has been found in a variety of human tumor types. To investigate the involvement of CDKI abnormality in mesenchymal chondrosarcoma, alterations of CDKIs were examined in human mesenchymal chondrosarcoma tissues using a quantitative DNA/PCR, PCR-SSCP. Seven of 33 specimens (21.2%) showed abnormally low levels of p16CDKN2A amplification, suggesting that the allelic deletion of the gene might be a less frequent event in progression of this tumor. To detect subtle sequence alterations such as point mutations, SSCP analysis of the entire coding region of the p16CDKN2A gene, exons 1, 2, and 3 regions, showed no altered SSCP patterns in 33 mesenchymal chondrosarcoma specimens. A low incidence of genetic alterations of the p16CDKN2A was found in mesenchymal chondrosarcoma. Through this study, we conclude that alteration of the p16CDKN2A gene does not participate significantly in the tumorigenesis of mesenchymal chondrosarcoma.

Base Sequence↗
PubMed2000

Distinct clinicopathologic and genetic profiles in sporadic gastric cancer with different mutator phenotypes.

A subset of sporadic gastric cancers (GC) exhibits microsatellite instability (MSI). To define the precise role of MSI in GC, a total of 100 patients with sporadic GC were classified into three groups, i.e., high-frequency MSI (MSI-H), low-frequency MSI (MSI-L), and microsatellite stable (MSS), based on 10 microsatellite markers. Mutational analyses of TGFbetaRII, IGFIIR, BAX, MSH3, MSH6, E2F4, MSH2, MLH1, and TP53 genes, and methylation and protein expression of MLH1 and MSH2 were performed and correlated. Twenty-seven percent of GC showed MSI at least in one locus and could be further graded as MSI-H (14%) and MSI-L (13%). No clinicopathologic difference was noted between GC with MSI-L and MSS. Compared with GC with MSI-L or MSS, GC with MSI-H had a significantly higher frequency of antral location, intestinal subtype, H. pylori seropositivity, but a lower incidence of lymph node metastasis, and displayed a higher frequency of frameshift mutations of TGFbetaRII, IGFIIR, BAX, MSH3, and E2F4 genes but a lower incidence of TP53 mutations. Furthermore, hypermethylation of the MLH1 promoter was responsible for the loss of protein function in 13 of 14 MSI-H tumors. It was concluded that a specific phenotype and a distinct profile of genetic alterations exist in MSI-H GC. We speculate that epigenetic inactivation of MLH1 by methylation plays a crucial role in initiating such a pathway of carcinogenesis. In contrast, GCs with MSS and MSI-L exhibit clinicopathologic features that are distinct from MSI-H tumors and have a higher frequency of TP53 mutations, suggesting that they may evolve through an entirely different pathway.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Influential factors affecting prognosis of snakebite patients management: Kaohsiung Chang Gung Memorial Hospital experience.

BACKGROUND: The objective of this study was to determine the most influential factors affecting the prognosis of snakebite patients in Kaohsiung Chang Gung Memorial Hospital. METHODS: A thorough review of the medical records of poisonous snakebite from June 1986 to November 1999 was carried out in this retrospective study. RESULTS: Of the identified snakes in 39 bite victims, 70% of these cases were hemorrhagic type: Trimeresurus stejnegeri 20/27, T. mucrosquamatus 6/27, and Agkistrodon acutus 1/27; 28% were neurotoxic type: Naja naja atra 6/11 and Bungarus multicinctus 5/11; and 2% was mixed type: Vipera russelli formosensis 1/39. Three of four acute renal failure victims were bitten by T. mucrosquamatus. Two of the 5 victims bitten by B. multicinctus required endotracheal intubation to maintain their respiration. Five patients received skin grafting, 3 of whom were bitten by Naja naja atra. Most of our patients (55%) received only a single dose of antivenin, and 83% (29/35) of the antivenin was given within 6 hours after the bite; the antivenin infusion was finished in less than 2 hours in most cases (33/36). CONCLUSION: Bites from Trimeresurus stejnegeri are the most common poisonous snakebite recorded in our emergency department. T. mucrosquamatus is prominent in causing bleeding tendency and acute renal failure. Bungarus multicinctus is more prominent than Naja naja atra in causing acute respiratory failure. The dosage of antivenin used to treat patient bitten by cobra was less than that recommended by the poison control center, and the complication of skin necrosis requiring skin grafting was more severe than that of the other species.

Adolescent↗
PubMed1999

Intravascular ultrasound comparison of chronic recoil among different stent designs.

Intravascular ultrasound studies were acquired in 70 native coronary artery lesions after implantation and at follow-up of Palmaz-Schatz, GFX, NIR, and CrossFlex stents. Chronic stent recoil was minimal in the Palmaz-Schatz, GFX, and NIR stents; however, there was small, but significant chronic recoil of the CrossFlex stent.

Coronary Disease↗
PubMed1999

Synthesis and activity of a new generation of ruthenium-based olefin metathesis catalysts coordinated with 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene ligands.

[formula: see text] A new family of 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene-substituted ruthenium-based complexes 9a-c has been prepared starting from RuCl2(=CHPh)(PCy3)2 2. These air- and water-tolerant complexes were shown to exhibit an increased ring-closing metathesis activity at elevated temperature when compared to that of the parent complex 2 and the previously developed complex 3. In many instances the activity of these complexes also rivaled or exceeded that of the alkoxy-imido molybdenum complex 1. Catalyst loadings of as low as 0.05 mol% could be used.

Alkenes↗
PubMed1999

Comparison of cilostazol versus ticlopidine therapy after stent implantation.

The aim of this study was to evaluate the efficacy of cilostazol for prevention of stent thrombosis compared with ticlopidine. Cilostazol is a potent antiplatelet agent with less serious side effects. However, few data are available about the effect of cilostazol in preventing stent thrombosis after coronary stent implantation. Four hundred ninety patients selected for elective stent placement were randomized to receive aspirin plus ticlopidine (n = 243) or aspirin plus cilostazol (n = 247) for 1 month. Clinical and laboratory evaluations were performed at regular interval. There were no differences in baseline characteristics between the 2 groups. During the first 30 days after stent implantation, major cardiac events or adverse drug effects were similar between the 2 groups: ticlopidine (2.9%) vs cilostazol (1.6%) group, p = NS; stent thrombosis (0.4% vs 0.8%, p = NS, respectively), myocardial infarction (0.4% vs 0.8%, p = NS), severe leukopenia (1.2% vs 0%, p = NS), severe thrombocytopenia (0.4% vs 0%, p = NS), and cerebral hemorrhage (0.4% vs 0%, p = NS). Adverse effects led to drug withdrawal in 7 patients in the ticlopidine group (2.9%) and in 5 in the cilostazol group (2.0%). There was no death during the follow-up period. Thus, aspirin plus cilostazol may be an effective antithrombotic regimen with comparable results to aspirin plus ticlopidine after elective coronary stenting.

Adult↗