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Biomedical subjects

S Chung

Publications and source records attributed to S Chung.

At least 145 records · Page 8Linked to original sources
PubMed1994

Family characteristics and offspring growth in various countries. III. Regression of offspring's stature in relation to parent's and family's factors in Japan and Korea.

1219 offspring 2-48 years old were examined in 578 Japanese and in 672 Korean families. To obtain age-independent values, we used 100-point T-scores. A multiple regression analysis, shows that the (tall) stature of Japanese offspring dependent on the genetic factor (tall stature of parents) in about 13%, on (large) family and apartment size in 0.4-1.5%, for sons also on (good) education and income of parents in 0.72%, and for daughters on (young) age of parents at child birth. In Korea, the (tall) stature of offspring was significantly related to the genetic factor (tall parents), which explained 1.8% of the variance for sons and 13% for daughters, and also to the (large) family apartment size, which explained 2.6% of the variance for sons and 0.84% for daughters. These results show in a different light the results obtained from the analysis of family types, and they provide evidence for the importance of the analysis of sets of traits in the form of family types, going beyond the importance of other multivariate techniques.

Adolescent↗
PubMed1994

Family characteristics and offspring growth in various countries. I. Frequency of various family types in Bulgaria, Japan, Korea, Mexico and Poland.

9936 families were analyzed from Bulgaria, Japan, Korea, Mexico, and Poland. A factor analysis revealed four factors: culture (F1), income (F2), genetics (F3), and family and apartment size (F4). Family types we coded as 1 if below the median and 2 if above the median. The most frequent types were represented by 1122, 2221, and 2211 (frequency 8.7-8.0%), and the least frequent by 1221 and 2111 (frequency 4.2-4.3%). Some similarity with respect to family types were found between populations: from Polish regions with heavy industry and seaside regions; from Polish towns under industrialization and from Mexico; from the Polish medium-size town of Lublin and Bulgarian towns; from Polish villages; from Polish mountain areas and north-eastern towns; from Korea; from Japan; from Polish cities.

Body Height↗
PubMed1994

A Th1 cell line (3E9.1) from resistant A/J mice inhibits induction of macrophage procoagulant activity in vitro and protects against MHV-3 mortality in vivo.

Induction of immune coagulants has been implicated in the pathogenesis of murine hepatitis virus strain 3 (MHV-3)-induced fulminant hepatic necrosis. Previous work from our laboratory has shown that the induction of procoagulant activity (PCA) correlates with the resistance/susceptibility to disease in inbred and recombinant inbred (RI) strains of mice. Macrophages from susceptible, but not resistant, strains of mice expressed increased levels of PCA in response to MHV-3 stimulation. T lymphocytes, however, had a marked regulatory role in the final expression of macrophage PCA. CD3+ CD4+ CD8- lymphocytes from RI H-2 compatible susceptible mice were able to instruct macrophages from susceptible mice to express significantly augmented levels of PCA, whereas CD3+ lymphocytes from RI H-2 compatible MHV-3-immunized resistant mice were able to suppress induction of PCA. In this present study, T-cell lines were derived from draining popliteal lymph nodes from resistant A/J mice, which had been immunized with MHV-3. All T-cell lines showed marked proliferation to MHV-3 and MHV-JHM which was major histocompatibility complex (MHC) restricted. All cell lines were CD3+, four of these were CD4+ and one was CD8+. All of the CD4+ cell lines produced IL-2 and two produced interferon-gamma (IFN-gamma), consistent with the Th1 cytokine profile. One cell line (3E9.1) was able to inhibit the induction of macrophage PCA through production of a soluble factor although cell-to-cell contact could not be excluded. This CD4+ T-cell line conferred protection to infected and susceptible AXB8 mice. These results demonstrate that the existence of a Th1 subpopulation of cells with a regulatory effect on macrophage PCA induction in MHV-3-infected mice contributes to the resistance of the A/J strain of mice to MHV-3 infection.

Animals↗
PubMed1994

Mutant p53 increases radioresistance in rat embryo fibroblasts simultaneously transfected with HPV16-E7 and/or activated H-ras.

Recently, it has been suggested that abrogation of the wild type p53 protein function may alter the cellular response to DNA damaging agents, including ionizing radiation. This study was designed to compre the relative radiosensitivity and tumorigenicity of rat embryo fibroblast (REF) cell lines transfected with a mutant form of the p53 gene (plasmid MTp53pro193), alone, or in combination, with the H-ras (plasmid pEJ6.6) and HPV16-E7 (plasmid pJ4 omega 16.E7) oncogenes. Transfection of the mutant p53pro193 gene alone resulted in selected clones having increased radioresistance in culture which correlated with increased mutant p53 expression in these clones. However, the co-transfection of mutant p53 and H-ras genes or triple transfection of mutant p53, H-ras and E7 genes resulted in clones with high mutant p53 expression, significantly increased radioresistance and uniform tumorigenicity. There was no correlation between intrinsic radioresistance and spontaneous metastasis in the tumorigenic REF transfectant clones. Stepwise acquisition of radioresistance and an aggressive tumor cell phenotype is observed when the mutant p53 gene and HPV E7 co-operate with the ras oncogene in transfection assays, and can be correlated to increases in mutant p53 expression.

Animals↗
PubMed1993

The importance of downstream delta-factor binding elements for the activity of the rpL32 promoter.

A salient feature of mammalian ribosomal protein genes is the location of promoter elements downstream, as well as upstream, of the transcriptional start point. Previous functional studies of the mouse rpL32 gene (Chung and Perry, Mol. Cell. Biol. 9, 2075; 1989) indicated that the first intron of this gene contains such an element. We show here that this element encompasses a binding site for a zinc finger nuclear protein known as delta (YY-1, muE1, UCRBP). The intronic delta site (delta i) is located 32 bp downstream of another delta site in the first exon (delta e). Transfection experiments with genes containing deleterious mutations in one or both delta sites or having alterations in the spacing between the sites indicate that the two delta elements function independently and contribute additively to the overall strength of the rpL32 promoter. Moreover, the contribution of the delta i element is the same whether it is oriented parallel or antiparallel to the delta e element. Together, the two delta elements raise the expression level about 10-fold over that attained by the upstream and initiator portions of the promoter. The positive role of the delta factor in rpL32 expression contrasts strikingly with its repressive role in various other genes.

Animals↗
PubMed1993

Resection of papillary transitional cell carcinoma using endoscopic snare.

We describe a method to remove papillary transitional cell carcinoma of the bladder using an adapted colonoscopic snare for transurethral electroresection. This method permits safe and accurate resection of papillary bladder tumors without the complications associated with the use of the resectoscope.

Carcinoma, Transitional Cell↗
PubMed1993

Restriction fragment length polymorphisms of the human aldose reductase gene: a preliminary report.

Abnormal metabolism through the polyol pathway during episodes of hyperglycaemia is implicated in the development of the chronic complications of diabetes. Since aldose reductase is the first and ratelimiting enzyme of the polyol pathway, it is predicted that restriction fragment length polymorphisms at the aldose reductase gene locus may influence catalytic activity and determine individual susceptibility to the diabetic complications. This paper reports the existence of EcoRI and TaqI restriction fragment length polymorphisms at the human aldose reductase locus.

Adult↗
PubMed1993

Diuretic renography in the evaluation of neonatal hydronephrosis: is it reliable?

Arguments against the use of diuretic renography in the assessment of newborn hydronephrosis include immature function of neonatal kidneys, previously reported poor diuretic response and nonreproducible drainage patterns. To address these concerns we reviewed the initial and followup renal scans of 17 neonates with hydronephrosis without ureterectasis diagnosed by perinatal ultrasonography. All patients were evaluated with an initial diuretic renal scan up to the age of 28 days, and all had normal cystograms. A total of 19 dilated kidneys was studied of which 13 ultimately required pyeloplasty and 6 were managed nonsurgically. Patient study parameters included age and weight at the time of each renal scan, side of hydronephrosis, differential function of each kidney, pre-diuretic and post-diuretic urine output, and drainage half-time of each kidney. The diuretic renal scans followed a standardized protocol. There was no statistically significant difference between neonatal and followup differential function (p > 0.05), and the correlation coefficient was highly significant (r = 0.968). Comparison of response to diuretic stimulation (ml./kg. per minute) revealed no statistically significant difference as the patients aged with brisk urine output 3 to 5 times greater than previously reported. The distribution and mean drainage half-times for normal nonhydronephrotic kidneys were similar when comparing those performed as neonates and at followup. Hydronephrotic kidneys managed nonsurgically maintained almost identical patterns. Those repaired surgically demonstrated appropriate improvement in drainage but function remained unchanged. These results refute each of the criticisms against the use of diuretic renography to evaluate neonatal hydronephrosis and demonstrate its reliability in neonates.

Furosemide↗
PubMed1993

Growth suppression of Friend virus-transformed erythroleukemia cells by p53 protein is accompanied by hemoglobin production and is sensitive to erythropoietin.

The murine allele temperature-sensitive (ts) p53Val-135 encodes a ts p53 protein that behaves as a mutant polypeptide at 37 degrees C and as a wild-type polypeptide at 32 degrees C. This ts allele was introduced into the p53 nonproducer Friend erythroleukemia cell line DP16-1. The DP16-1 cell line was derived from the spleen cells of a mouse infected with the polycythemia strain of Friend virus, and like other erythroleukemia cell lines transformed by this virus, it grows independently of erythropoietin, likely because of expression of the viral gp55 protein which binds to and activates the erythropoietin receptor. When incubated at 32 degrees C, DP16-1 cells expressing ts p53Val-135 protein, arrested in the G0/G1 phase of the cell cycle, rapidly lost viability and expressed hemoglobin, a marker of erythroid differentiation. Erythropoietin had a striking effect on p53Val-135-expressing cells at 32 degrees C by prolonging their survival and diminishing the extent of hemoglobin production. This response to erythropoietin was not accompanied by down-regulation of viral gp55 protein.

Animals↗
PubMed1993

Effects of galactose feeding on aldose reductase gene expression.

Aldose reductase (AR) is implicated in the pathogenesis of the diabetic complications and osmotic cataract. AR has been identified as an osmoregulatory protein, at least in the renal medulla. An outstanding question relates to the response of AR gene expression to diet-induced galactosemia in extrarenal tissues. This paper shows that AR gene expression in different tissues is regulated by a complex multifactorial mechanism. Galactose feeding in the rat is associated with a complex and, on occasions, multiphasic pattern of changes in AR mRNA levels in kidney, testis, skeletal muscle, and brain. These changes are not in synchrony with the temporal sequence of changes in tissue galactitol, galactose, and myoinositol concentrations. Moreover, galactose feeding results in changes in tissue AR activities that are not related, temporally or quantitatively, to the alterations in tissue AR mRNA or galactitol levels. It is concluded that AR gene expression and tissue AR activities are regulated by mechanisms that are not purely dependent on nonspecific alterations in intracellular metabolite concentrations. This conclusion is supported by the finding that chronic xylose feeding, despite being associated with intracellular xylitol accumulation, does not result in alterations in AR mRNA levels, at least in the kidney.

Aldehyde Reductase↗
PubMed1993

Internal fixation of the thoracic and lumbar spine using Roy-Camille plates.

Thirty patients underwent fixation of the thoracic and lumbar spine from 1986 to 1990 using the Roy-Camille pedicular screw fixation system. The spine was stabilized for a variety of pathologic entities including fracture, tumor, spondylolisthesis, postlaminectomy instability, and pseudarthrosis. All but one patient obtained solid fusion based on radiographic and clinical criteria with an average follow up of 19.5 months. All patients reported subjective improvement in preoperative pain levels. There were no neurologic complications associated with the surgical procedure. Roy-Camille plate fixation appears to offer a stable surgical construct in the treatment of thoracic and lumbar spine instability.

Adolescent↗
PubMed1993

Concurrent strong tyrosine phosphorylation of a 42,000 MW ERK and a 100,000 MW protein is associated with IL-2 production in human Jurkat T cells.

The tyrosine phosphorylated protein(s) responsible for the signalling for interleukin-2 (IL-2) production has not been clearly defined. In this study, the relationship between IL-2 production and the protein tyrosine phosphorylation pattern of human Jurkat T cells was investigated using phosphotyrosine immunoblotting analysis. With anti-CD3 or anti-CD2 activation the cells showed only a low (anti-CD3) or a moderate (anti-CD2) level of tyrosine phosphorylation of a 42,000 MW external signal-regulated kinase (ERK), which was accompanied by undetectable (anti-CD3) or low level (anti-CD2) IL-2 production. In the presence of phorbol myristate acetate (PMA), large amounts of IL-2 were induced by both anti-CD3 and anti-CD2 stimulation, which was accompanied by strong concurrent tyrosine phosphorylation of the 42,000 MW ERK and a 100,000 MW protein. PMA alone, which induced high levels of tyrosine phosphorylation of the ERK protein, neither induced any detectable IL-2 nor increased the level of tyrosine phosphorylation of the 100,000 MW protein. These observations suggest that concurrent tyrosine phosphorylation of the 42,000 MW ERK and a 100,000 MW protein may be required for IL-2 production.

Antigens, CD↗