Search PubMed⌕ Search

Biomedical subjects

Y Park

Publications and source records attributed to Y Park.

252 records · Page 14Linked to original sources
PubMed1985

Thallium perfusion and cardiac enzyme abnormalities in patients with familial hypertrophic cardiomyopathy.

Twelve patients of five families with familial hypertrophic cardiomyopathy were examined. Within each family, the older patients showed dilation or diminished contraction of the left ventricle by echocardiography or angiocardiography more frequently than did younger patients. LDH1 fraction (lactic dehydrogenase isoenzyme) and MB-CPK (creatinine phosphokinase isoenzyme) were increased in 7 of 10 patients. Thallium-201 myocardial scintigraphy showed perfusion defect or hypoperfusion in 9 of 10 patient. Eleven cases demonstrated remarkable hypertrophy at the macroscopic level. Marked fibrosis was observed in all 5 of the 11 patients whose histologic findings were obtained. In two necropsy cases, disarray was found throughout the right and left ventricles and the pattern of fibrosis was massive. These findings were different from those of ordinary hypertrophic cardiomyopathy. It is possible that each patient with familial hypertrophic cardiomyopathy may develop more prominent thallium and enzyme abnormalities as he becomes older, regardless of whether he develops a dilated cardiomyopathy picture.

Adolescent↗
PubMed1985

[The introduction of an urodynamic technic synchronized with videocystourethrograms and its data management].

The video urodynamics that simultaneously display urodynamic data with radiographic visualization of the lower urinary tract on television monitors was first described by Miller in 1967. This technique has been developed in a growing number of urodynamic laboratories in North American and European countries. The 2100 uro color video system manufactured by DISA elektronik A/S was introduced into our clinic in September in 1984. We have been aware of the lack of a satisfactory way of measuring the function of the bladder neck and posterior urethra during micturiton. But now, from our experience using this system, we conclude that video urodynamics is a comprehensive means of assessing, lower urinary tract disorders.

Computers↗
PubMed1984

Induction of a distinct nuclear poly(A) polymerase and the production of anti-tumor poly(A) polymerase antibodies in hepatocarcinogenesis.

Primary hepatomas induced in rats by an azo dye contained a distinct nuclear poly(A) polymerase which was different from the corresponding normal liver enzyme with respect to molecular weight and peptide map. The two enzymes could also be distinguished by their immunological characteristics. Sera from the carcinogen-fed rats contained antibodies to the tumor poly(A) polymerase even before the appearance of neoplastic nodules.

Animals↗
PubMed1983

Vincristine, adriamycin, and mitomycin (VAM) therapy for previously treated breast cancer. A preliminary report.

Fifteen patients with metastatic breast cancer previously treated with chemotherapy were treated with a regimen consisting of vincristine, Adriamycin, and mitomycin. Eleven patients (73%) responded with three complete and eight partial responses. The median duration of response was eight months. While all four nonresponders died within five months, the median duration of survival of responders was 18 months. Toxicity was significant but tolerable. Thus, this preliminary report suggests that this regimen is active in advanced previously treated breast cancer, providing meaningful remissions with acceptable toxicity.

Adult↗
PubMed1982

Pulmonary regurgitation studied with the ultrasonic pulsed Doppler technique.

Sixty patients with pulmonary regurgitation were studied by the pulsed Doppler technique combined with two-dimensional and M-mode echocardiography. Patients with pulmonary regurgitation had abnormal Doppler signals just below the pulmonic valve in the right ventricular outflow tract in diastole on the two-dimensional image. These signals were considered to indicate the regurgitant flow. There are two patterns of pulmonary regurgitant Doppler signals. In pulmonary hypertension, the maximal component of instantaneous flow velocity is sustained at about the same signal strength throughout diastole, but when the pulmonary arterial pressure is normal, the velocity slows down gradually from early diastole to end-diastole. Pulmonary regurgitation was detected by phonocardiography in about half the patients. In the remaining half, pulmonary regurgitant murmur could not be differentiated from aortic regurgitant murmur or was masked by coexistent aortic regurgitation or patent ductus arteriosus, whereas the Doppler technique indicated pulmonary regurgitation.

Adolescent↗
PubMed1981

Prostatic cancer with an unusual presentation: polymyositis and mediastinal adenopathy.

A 67-year-old man with prostate cancer presented with acute polymyositis and vocal cord paralysis as a result of mediastinal lymphadenopathy. His clinical course was unusual, with the development of a malignant pleural effusion, supraclavicular adenopathy, and osteolytic bone lesions. Urologic symptoms developed only pre-terminally, and osteoblastic bone metastases were not documented. This case suggests that prostate cancer need not have a simple natural history.

Adenocarcinoma↗
PubMedDate not supplied

Genetic susceptibility factors of Type 1 diabetes in Asians.

Type 1 diabetes is a multifactorial disease in which the insulin producing beta-cells of the pancreas are destroyed by the immune system, a process determined by the activity of major histocompatibility complex (MHC)-restricted T lymphocytes. Progress has been made in elucidating genetic factors involved in Type 1 diabetes in Caucasians, with less data available from Asia. For Asians, the human MHC locus (HLA region), especially the class II region, is the major susceptibility interval. The role of IDDM2, the insulin locus, has been questioned in Asia. In contrast to Caucasians, Asian populations have a very low incidence of Type 1 diabetes (0.4-1.1 cases/year/100 000 individuals). This low incidence rate in the Asian population may be related to the population frequency distribution of susceptible Type 1 diabetes genes, especially of HLA. The overall risk for Type 1 diabetes from HLA DR and DQ is determined by polymorphic residues (alleles) and particular combinations of alleles (haplotypes and genotypes) in a given individual. In Asians, it is very common that a protective DR4 allele is associated with susceptible DQ alleles while neutral/protective DQ alleles are associated with the susceptible DR4 alleles. Our analyses indicate that the counterbalancing between susceptible DRB1 and protective DQB1, and vice versa, is a factor that may contribute to the low incidence of diabetes in Asians. We find that identical HLA DRB1-DQB1 haplotypes of Asians and Caucasians have similar transmission to diabetic children and similar associations with diabetes. Moreover, the association with diabetes and transmission to a diabetic offspring of DR4 haplotypes varies depending on the haplotype borne on the homologous chromosome. This might contribute not only to the synergistic effect of DR3/4, but also to the susceptibility influence of DQB1*0401 haplotypes confined to DR4/X. High-risk DR4 subtypes were predominant in DR4/X, whereas protective DR4 subtypes were observed mainly in the DR3/4 genotype. Since in Asians DQB1*0401 is in linkage disequilibrium (LD) with DRB1*0405, we find more DRB1*0405-DQB1*0401 haplotypes in patients with DR4/X than in patients with DR3/4, suggesting that the contribution of the DRB1 locus may be greater in DR4/X than in DR3/4 genotypes. Several genome scans suggested additional susceptibility intervals and provided supporting evidence for several previously reported linkages. Other studies focused on the confirmation of linkage using multipoint sib-pair analyses with densely spaced markers and multiethnic collection of families. Although significant and consistent linkage evidence was reported for the susceptibility intervals IDDM12 (on 2q33) even in Asia, evidence for most other intervals varies in different data sets. LD mapping has become an increasingly important tool for both confirmation and fine-mapping of susceptibility intervals, as well as identification of etiological mutations. The examination of large and ethnically varied data sets including those of Asia has allowed identification of haplotypes that differ only at a single codon in a single locus. As more data become available, the study of pairs of haplotypes which differ at a single polymorphic site, but have different effects on disease susceptibility, should allow more precise definition of the polymorphisms involved in the disease process.

Asia↗
PubMedDate not supplied

Constitutive and induced expression by pyridine and beta-naphthoflavone of rat CYP1A is sexually dimorphic.

Adult male and female Sprague-Dawley rats were compared in terms of the constitutive levels and inducibility of CYP1A1 and CYP1A2 (CYP1A) in lung, kidney, and liver. CYP1A were induced by i.p. treatment with pyridine (75 mg/kg per day) or beta-naphthoflavone (betaNF; 25 mg/kg per day) for two consecutive days and analyzed catalytically (via O-dealkylation of resorufin ethers), at the protein level (by Western blot analysis) and at the mRNA level (by Northern blot analysis). In untreated rats. CYP1A1 protein and its mRNA were detectable only in the lung and kidney of females but not males, whereas CYP1A2 protein and its mRNA were detectable only in the liver in either gender. Pyridine treatment upregulated CYP1A1 mRNA and its protein in the lung, kidney and liver in female rats, and upregulated the mRNA but not the protein in the lung and liver in male rats. Conversely, pyridine induced both CYP1A2 mRNA and protein in the liver in female rats, whereas it induced the protein but not its mRNA in the liver in male rats. No gender difference was observed in the plasma elimination rate of administered pyridine. BetaNF, in contrast to pyridine, induced CYP1A proteins, activities, and mRNA to higher levels in male than in female rats. The results show that the constitutive as well as inducible expression of CYP1A is sexually dimorphic in the Sprague-Dawley rat, with females being more responsive than males to induction by pyridine but with males being more responsive than females to induction by betaNF. The findings support the involvement of different mechanisms in CYP1A induction by pyridine and betaNF.

Animals↗
PubMedDate not supplied

Assessment of disinfection by-products in drinking water in Korea.

The main purpose of applying the chlorination process during water treatment is for disinfection. Research results, however, indicate that disinfection byproducts (DBPs) including trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), haloketones (HKs), and chloropicrin (CP) can be produced by the chlorination process. Some of these DBPs are known to be potential human carcinogens. This 3-year project is designed to establish a standard analysis procedure for DBPs in drinking water of this country and investigate the distribution and sources of specific DBPs. The occurrence level of DBPs in drinking water was below 50 micrograms/l in most cases. THMs in plant effluent accounted for 60% of all DBPs measured, whereas HAAs accounted for 20%, HANs 12%, HKs 5% and CP 3%. Chloroform was found to be the major THMs compound (77%), followed by bromodichloromethane (BDCM, 18%) and bromoform (BF, 3%). The concentration of DBPs formed in distribution systems increased from those detected in plant effluent. Comparison of humic acid and sewage as precursors for THMs formation showed that humic acid was the major THMs precursor. Results would play an important role in exposure assessment as a part of the risk assessment process, and would give basic information for establishment of DBPs reduction and management procedures.

Chlorine↗
PubMedDate not supplied

Quantitation of c-erbB-2 gene amplification in breast cancer tissue by competitive PCR.

Controversy exists regarding the relationship of the degree of c-erbB-2 amplification to other prognostic factors in breast cancer. To determine the degree of amplification of c-erbB-2 exactly, a sensitive and quantitative method is required. We have developed a competitive PCR method to quantitatively determine the amplification of the c-erbB-2 oncogene. Using this method, we evaluated DNA from 27 breast cancer tissue specimens and DNA from peripheral blood leukocytes from a normal individual. Regarding the relationship between the degree of c-erbB-2 amplification and clinicopathological factors, we found a greater degree of amplification of the c-erbB-2 oncogene in estrogen receptor- negative or progesterone receptor-negative specimens than in positive ones and in lymph node metastasis-positive specimens than in negative specimens, in stages II, III, and IV of disease compared with stage I disease, and in samples with positive lymphatic vessel invasion than with no lymphatic vessel invasion. Generally, these factors were seen in the group of patients who had a bad prognosis. By univariate analysis and multivariate analysis, reverse correlation was observed between amplification of c-erbB-2 and overall survival. Regarding disease-free survival, these relationships were observed only with univariate analysis in our group of patients.

Adult↗
PubMedDate not supplied

Modulation of MCF-7 breast cancer cell signal transduction by linoleic acid and conjugated linoleic acid in culture.

The effects of modifying membrane fatty acid composition on cell growth, phospholipase C (PLC) and protein kinase C (PKC) activities, and prostaglandin E2 (PGE2) secretion were investigated. Hormone responsive MCF-7 human breast cancer cells were incubated in a serum-free medium containing epidermal growth factor and supplemented with physiologic concentrations (0.18-1.78 x 10(-5) M) of linoleic acid (LA) or conjugated linoleic acid (CLA). Linoleic acid stimulated cancer cell growth, while CLA was inhibitory. Supplementation with LA or CLA altered cell membrane composition. Linoleic acid stimulated PLC activity with or without GTP gamma (S), and tended to increase membrane PKC activity. However, CLA supplementation did not modify membrane PLC or PKC activity. Prostaglandin E2 secretion was not influenced by LA or CLA. These data show that growth inhibition by CLA was not mediated through PLC-, PKC- or PGE2-dependent signal transduction pathways, suggesting that another inhibitory mechanism may be involved. Although biological differences appeared to be modest (5-20% of control), the fact that LA and CLA treatment resulted in significant biological effects at physiologic concentrations is relevant, since most human cancers require years to develop.

Anticarcinogenic Agents↗
PubMedDate not supplied

Electrodiagnostic criteria in CIDP: comparison with diabetic neuropathy.

This study examines current criteria for CIDP by comparing the electrodiagnostic data from 17 patients who have biopsy proven CIDP with 29 patients with diabetic neuropathy. The groups were comparable in age. Data were examined using four sets of published criteria for primary demyelination. Two sets (A & B) defined demyelination based on distal motor latencies, F-wave latencies, motor conduction velocities, and temporal dispersion or conduction block. The other two sets defined demyelination based on slowing of motor conduction velocity < 70% of the lower limit of normal (LLN) in either 2 nerves (set C), or in a single nerve (set D). Using set A, 3/17 patients with CIDP met the criteria for a demyelinating neuropathy, while this was true in 2/29 of the patients with diabetic neuropathy. For sets B and C, data consistent with a demyelinating neuropathy were identified in 2/17 and 1/29 patients, respectively. Using set D criteria for demyelination was met in 6/17 of the patients with CIDP and in 5/29 of the diabetic patients. None of the criteria sets showed a significant difference between CIDP and diabetic neuropathy (p = 0.3 to 0.5). Though electrodiagnosis is an important element in the diagnosis of CIDP, current electrodiagnostic criteria alone are insufficient for defining many cases of CIDP.

Adult↗