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Biomedical subjects

W S Yang

Publications and source records attributed to W S Yang.

At least 73 records · Page 4Linked to original sources
PubMed1991

Effects of Hantaan virus on human endothelial cells and their significance in pathogenesis of hemorrhagic fever with renal syndrome.

The effects of Hantaan virus (HTNV) on human endothelial cells (HECs) were investigated both in vivo and in vitro. The 76-118 strain or SR-11 strain of HTNV were inoculated into HECs monolayers respectively, and the virus antigens could be detected on the seventh day of the first passage after inoculation by immunofluorescent technique. The HTNV could also be isolated through cultures of Vero E-6 cells. HTNV particles and inclusion bodies together with various changes in the organelles were observed in the infected cells by transmission electronic microscopy (TEM), and the immunoenzyme positive virus particles were seen by immunoelectronic microscopy. Samples of skin biopsy were individually obtained from 14 cases of hemorrhagic fever with renal syndrome on the second to the fifth day after the onset of the illness. It was found that HTNV antigens were widely distributed in the cytoplasm of endothelial cells of the samples from 5 out of 14 cases by avidin-biotin-peroxidase complex staining, and morphologic changes of the endothelial cells similar to those observed in vitro, were also seen by TEM. The results indicated that HEC is one of the target cells susceptible to HTNV. The virus could invade and propagate in HECs, and could induce damage to the latter.

Antigens, Viral↗
PubMed1990

Human hepatic regenerative stimulator substance: partial purification and biological characterization of hepatic stimulator substance from human fetal liver cells.

Current support or replacement therapies for fulminant acute hepatic failure are frequently very disappointing. In this study, human hepatic stimulator substance--a liver-specific growth factor--was partially purified from human fetal liver cells and characterized by its biological effects. Almost 70-fold protein content was purified with an approximately 80-fold increase in specific growth stimulator activity. Human hepatic stimulator substance proved to be heat-stable, protease-sensitive, organ-specific and species-nonspecific. Human hepatic stimulator substance produced a two- to threefold increase of 3H-thymidine incorporation into hepatic DNA when injected intraperitoneally into growing weanling mice (nonhepatectomized) or regenerating rats (34% hepatectomy). The effects of hHSS in reversing the lethality of D-galactosamine (1.6 gm/kg body weight)-induced hepatic necrosis in rats were further evaluated. A survival rate of 4% (n = 24), 41% (n = 12, p less than 0.05), 33% (n = 12, p less than 0.05), 31% (n = 13, p less than 0.05) and 18% (n = 11, p greater than 0.05) was observed when the rats were injected with 4 ml of saline intraperitoneally, 4 ml of human intact fetal hepatocytes (2.4 x 10(8] intraperitoneally, 4 ml of human hepatic stimulator substance intraperitoneally, 2 ml of twofold concentrated human hepatic stimulator substance intravenously and 1 ml of fourfold human hepatic stimulator substance intramuscularly, respectively, 20 hr after poisoning.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Abnormalities of T cell immunoregulation in hemorrhagic fever with renal syndrome.

The functions of spontaneous suppressor T cells and T lymphocyte subsets in patients with hemorrhagic fever with renal syndrome were compared. In the early stages of disease, decreased activity of spontaneous suppressor T cells was concurrent with increased numbers of CD8+ cells and a reversed CD4:CD8 ratio. These changes were related to abnormalities in serum C3 level and circulating immune complexes. In the recovery stages of the illness, spontaneous suppressor T cell activity and T cell subsets returned to normal levels.

Antigen-Antibody Complex↗
PubMed1990

[The study on the orthodontic patients who visited department of orthodontics, Seoul National University Hospital].

From 1965 to 1974, the total number of the orthodontic patients who visited Seoul National University Hospital was only about 1000. But in the last several years the number has been increasing so rapidly that we have about 1000 new orthodontic patients every year. This made it necessary to undertake an epidemiologic study on them so that we can accommodate their orthodontic needs adequately. Accordingly, the present study was done in an attempt to provide reliable quantitative information regarding the characteristics of malocclusion-Angle's classification etc.--of patients who visited Department of Orthodontics, Seoul National University Hospital from 1985 to 1989. The total number was 3305. This study sought to determine the annual trend in total number during 5 years, frequency in each age and sex group and distribution according to Angle's classification. It was found that: 1. Total number of orthodontic patients has been increasing and the number of female patients was 1.55 times as high as that of male. 2. Percentage of Class III malocclusion has been increasing, but that of Class I decreasing. Each percentage of Class I, Class II div. 1, Class II div. 2 and Class III was 35.92%, 13.40%, 1.54%, and 49.14%. 3. Percentages of 8 to 12-year-old group and 12 to 18-year-old group showed decreasing trends, but that of adult patients showed increasing trend.

Adolescent↗
PubMed1990

[Soft X-ray study on fetal cranio-facial growth and development].

This study was undertaken to ascertain the changes of fetuses in craniofacial dimension and to evaluate the growth and development during fetal period. Lateral cephalograms by soft X-ray were taken from 64 fetuses and were measured in linear and angular aspects. The following conclusions were obtained. 1. The linear increase rates of anterior cranial base length exceeded those of the posterior cranial base length. 2. Growth increments on horizontal dimension were greater than vertical dimension in the maxilla. 3. The cranial base angle was almost constant after fetal period 13 weeks with the average angle of 130 degrees. 4. The angle between anterior cranial base and palatal plane was decreased gently during fetal period.

Cephalometry↗
PubMed1989

The distribution and duration of hantaan virus in the body fluids of patients with hemorrhagic fever with renal syndrome.

The distribution and duration of Hantaan virus (HTNV) in the body fluids of patients were studied by immunofluorescence, reverse passive hemagglutination, and cell culture assays. Virus antigen of hemorrhagic fever with renal syndrome in peripheral blood mononuclear cells (PBMCs) was usually present before day 11 of the disease, especially from days 4-7. Virus isolates were more readily recovered from plasma early in the course of the illness and less frequently after day 7. The use of PBMCs rather than plasma enabled isolates to be recovered at a rate nearly twice that permitted by plasma and allowed the isolation peak of HTNV (days 4-7 after onset of disease) to extend an additional 2 or 3 d, thus prolonging the period of detectable viremia until days 8-11. PBMCs were especially useful in isolating viruses from patients with hemorrhagic fever with renal syndrome in whom antibody titers were generally high during the acute phase of the disease. HTNV was isolated from the cerebrospinal fluid of patients, but was difficult to recover from other body fluids.

Antibodies, Monoclonal↗
PubMed1989

The duration of viremia patients with epidemic hemorrhagic fever.

The duration of viremia in patients with epidemic hemorrhagic fever (EHF) was studied using immunofluorescence technique and cell culture assays. The duration of virus in plasma of EHF patients was about 1 week, which was concomitant with the febrile phase of the disease. Comparatively, the separation rate of viruses in peripheral blood mononuclear cells (PBMC) was greater (1.8 times) than in plasma, while the detected peak of EHF (in 4-7 days after onset of the disease) was found to be 2 or 3 days less than that of plasma, thus the detectable viremia was prolonged until the 8th to 11th day of the disease. High titre EHF antibody of IgG, TgM was unable to neutralize the virus in human blood. The results revealed that a blood-cell-associated prolonged viremia is one of the characteristics of EHF infection.

Antibodies, Viral↗
PubMedDate not supplied

Hypoalbuminemia as a risk factor for progressive left-ventricular hypertrophy in hemodialysis patients.

BACKGROUND: This study was performed to evaluate the changes in left-ventricular (LV) mass in the patients starting maintenance hemodialysis and the risk factors for the progression of LVH. METHODS: From June 1994 to February 1997, baseline echocardiography was obtained within six months after the initiation of hemodialysis in 111 patients with end-stage renal disease. Of the patients who had LVH on baseline echocardiography, 32 patients underwent follow-up echocardiography after 15 months (range: 9-24 months). LVH was defined as a left-ventricular mass index (LVMI) greater than 131 g/m(2) in males and 100 g/m(2) in females. Progressive LVH was defined as a follow-up LVMI greater than 105% of the baseline value. Hemoglobin, blood urea nitrogen, creatinine, cholesterol, albumin, prealbumin, parathyroid hormone, Kt/V, nPCR, fibrinogen, homocysteine and ACE gene polymorphism were also measured. RESULTS: LVH was detected in 91 of 111 (82%) ESRD patients starting maintenance hemodialysis. Of the 32 patients in whom follow-up echocardiography was performed, progressive LVH occurred in 19 patients (M:F = 12:7). Progressive LVH was associated with lower diastolic blood pressure (81 +/- 11 vs. 90 +/- 12 mm Hg, p = 0.036) and lower serum albumin (3.5 +/- 0.4 vs. 3.9 +/- 0.4 g/dl, p = 0. 009). Serum albumin was negatively (r = -0.420, p = 0.017) correlated to Delta LVMI (follow-up LVMI minus baseline LVMI). Hypoalbuminemia was an independent risk factor for progressive LVH in multiple logistic regression analysis (R.R. = 1.29, p = 0.046). The association of progressive LVH with age, gender, diabetes mellitus, smoking history or other laboratory parameters was not significant. CONCLUSION: LVH was highly prevalent in the patients starting maintenance hemodialysis for ESRD. In the follow-up echocardiography, LVH progressed in a substantial portion of the patients, and hypoalbuminemia was a risk factor for progressive LVH.

Adult↗
PubMedDate not supplied

Interleukin-1beta stimulates the production of extracellular matrix in cultured human peritoneal mesothelial cells.

OBJECTIVE: To investigate the effect of interleukin-1beta (IL-1beta) on the production of extracellular matrix in cultured human peritoneal mesothelial cells (HPMCs). DESIGN: Cultured HPMCs were treated with or without IL-1beta. Cell morphology was observed. The expression of fibronectin, alpha1(I) procollagen, and transforming growth factor-beta1 (TGFbeta1) mRNAs was measured by Northern blot analysis. The cell surface expression of fibronectin and type I collagen was evaluated by immunofluorescent staining. Fibronectin and type I collagen in culture supernatant were measured by inhibition ELISA. RESULTS: Interleukin-1beta induced morphologic change in HPMCs from a cuboidal epithelioid shape into an elongated fibroblastoid shape. The elongated cells were positive for cytokeratin although they had a fibroblastoid appearance. Treatment of HPMCs with IL-1beta resulted in increased expression of both fibronectin and alpha1(I) pro-collagen mRNA in dose- and time-dependent manners. Immunofluorescent staining showed strong and diffuse cytoplasmic expression of fibronectin and type I collagen in the cells treated with IL-1beta, whereas only weak perinuclear cytoplasmic staining was noted in the cells on media alone. The concentrations of secreted fibronectin and type I collagen in culture supernatant were significantly higher in the cells treated with IL-1beta than in the control cells. IL-1beta also stimulated the expression of TGFbeta1 mRNA. However, IL-1beta-induced fibronectin mRNA expression was only partially blocked by neutralizing anti-TGFbeta antibody. CONCLUSION: Interleukin-1beta stimulated the production of extracellular matrix in cultured HPMCs along with the induction of morphologic changes. This may play a role in the development of peritoneal fibrosis caused by peritonitis or bioincompatible dialysate in continuous ambulatory peritoneal dialysis patients.

Cells, Cultured↗