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Biomedical subjects

S Y Song

Publications and source records attributed to S Y Song.

At least 73 records · Page 4Linked to original sources

Establishment and characterization of human gastric carcinoma cell lines.

We report 8 newly established gastric-carcinoma cell lines (SNU-216, 484, 520, 601, 620, 638, 668, 719) from Korean patients. Morphologic study was carried out using light and electron microscopes. CEA, alpha FP, and CA 19-9 and TPA in supernatant and in cell lysate were measured by radioimmunoassay. p53 and c-Ki-ras gene mutations were screened and confirmed by sequencing. The cell lines, derived from tumors with moderate differentiation, grew as a diffuse monolayer, and those from tumors with poor differentiation and minimal desmoplasia grew exclusively as non-adherent. Out of the 8 gastric-cancer cell lines, 5 had detectable levels of CEA both in supernatant and in cell lysate; there was no expression or secretion of alpha FP in these cells; 4 cell lines showed high levels of CA 19-9 in cell pellets. All cell lines except SNU-484 had high concentrations of TPA both in cell lysate and in supernatants. p53 mutation was found in 6 cell lines (75%): 2 (SNU-216 and SNU-668) had mutations in exon 6, and other 3 in exon 8. The c-Ki-ras mutation was found in 2 cell lines (25%), SNU-601 and SNU-668. The former showed GGT-to-GAT transition mutation at codon 12, while the latter showed CAA-to-AAA transversion mutation at codon 61. DNA profiles using restriction endonuclease HinfI and polymorphic DNA probes ChdTC-15 and ChdTC-114 showed different unique patterns; which suggests that these cell lines are unique and not cross-contaminated. We believe that the newly characterized gastric-cancer cell lines presented in this paper will provide a useful in vitro model for studies related to human gastric cancer.

Adult↗

Abnormal expression of four novel molecular markers represents a highly aggressive phenotype in breast cancer. Immunohistochemical assay of p53, nm23, erbB-2, and cathepsin D protein.

BACKGROUND: In view of the cumulative results to date, p53, nm23, erbB-2, and cathepsin D are the most promising investigational prognostic factors in breast cancer. OBJECTIVES: The clinical utility of these molecular markers to predict recurrence was evaluated. METHODS: Archival pathology tissues of 100 breast cancer patients were analyzed by immunohistochemical assay. Molecular biologic data were merged with clinicopathologic variables. RESULTS: Thirty-two patients (32%) had recurrence of disease at a median follow-up of 48 months (range 26-72 months). Investigational factor expression had statistical correlation for recurrence with increasing coexpression: one variable 20.6%, two variables 34.2%, three variables 47.1%, four variables 80.0% (P = 0.003). In univariate analysis, lymph node metastasis, tumor size, erbB-2 protein overexpression, and loss of nm23 protein expression were significant variables to determine recurrence; in multivariate analysis, node status and tumor size emerged as the most significant variables for recurrence. CONCLUSIONS: Coexpression of the studied investigational variables functioned as significant prognostic correlates for recurrence. These findings suggest that the studied investigational prognostic factors possess the ability to discriminate a highly aggressive phenotype in breast cancer.

Biomarkers, Tumor↗

Distribution of nitric oxide in the nasal mucosa of the rat: a histochemical study.

We evaluated the distribution of nitric oxide (NO) in the rat nasal mucosa using nicotineamide adenosine dinucleotide phosphate (NADPH)-diaphorase histochemistry. The NADPH-diaphorase positive nerve fibers in the nasal mucosa were observed around blood vessels and submucosal glands and in sphenopalatine ganglions. Strong positive reactions for NADPH-diaphorase were observed in ganglions as compared with the other tissues. In septal and turbinate mucosa, positive reactions for NADPH-diaphorase were mainly seen in the anterior portion, and a few positive reactions were observed in the posterior portion. No positive reactions for NADPH-diaphorase were demonstrated in the sinus mucosa. These results suggest that NO may be related to regulation of blood flow, glandular secretion and neurotransmission, and also that NO may play an important role in the defense mechanism of the upper airway system against external environments.

Animals↗

Comparison of the hemostatic effect of endoscopic injection with fibrin glue and hypertonic saline-epinephrine for peptic ulcer bleeding: a prospective randomized trial.

BACKGROUND AND STUDY AIMS: Although endoscopic injection therapy using various agents has been considered the least expensive and most effective technique in obtaining hemostasis in peptic ulcer bleeding, most of these agents induce tissue necrosis or degeneration. Theoretically the injection of fibrin glue (FG) to halt peptic ulcer bleeding may be safer than the use of other agents, but randomized clinical trials to compare the efficacy of FG and other agents are rare. The aim of this study was to compare the hemostatic efficacy between FG and hypertonic saline-epinephrine (HSE) in peptic ulcer bleeding. PATIENTS AND METHODS: From March 1992 to December 1993 we conducted a prospective randomized trial in 127 patients with peptic ulcer bleeding, in whom a visible vessel or active bleeding was identified. Patients were randomized into two groups, an FG group comprising 64 patients who received FG injections, and an HSE group, comprising 63 patients who received HSE injections. RESULTS: The two groups were comparable with regard to age, sex, bleeding focus and bleeding stigma. Permanent hemostasis using only endoscopic treatment was achieved in 59 cases (92.2 %) in the FG group and in 54 cases (85.7 %) in the HSE group. Rebleeding occurred in seven cases (10.9%) in the FG group and in 14 cases (22.2%) in the HSE group (P=0.087); emergency surgery was undertaken in four (6.3%) and seven cases (11.1%), respectively (P = 0.33); death occurred in one case (1.6%) and four cases (6.3%), respectively (P = 0.165). CONCLUSIONS: These results suggest that endoscopic injection of FG is an effective method in the control of peptic ulcer bleeding. However, even though there is a strong trend supporting the hypothesis that fibrin glue is superior to HSE, no statistically significant differences are noted. A trial involving larger numbers may produce a positive result.

Epinephrine↗

Active peptides from the carboxyl-terminal globular domain of laminin alpha2 and Drosophila alpha chains.

The laminin alpha1 chain carboxyl-terminal globular domain (G domain) contains multiple biological activities. Recently, we identified five cell binding sequences from the G domain by screening with overlapping 12-mer peptides encompassing the entire domain. The structures of these five sequences in the alpha1 chain are conserved in the corresponding regions of the different laminin alpha chains. Here we characterize the adhesion activities of the corresponding peptide segments from both the mouse laminin alpha2 chain and Drosophila laminin alpha chain using peptide-coated plastic plates and peptide-conjugated Sepharose beads. Using several cell lines, the laminin alpha2 chain peptides showed cell attachment and/or spreading activities with cell type specificities. Cell spreading on MG-10 was inhibited by integrin antibodies. Four of the Drosophila laminin peptides showed cell attachment activities. These results suggest that biologically active regions in the G domain are conserved in the laminin alpha1 and alpha2 chains, and that these regions in laminin play an important role in cell surface receptor interactions.

Amino Acid Sequence↗

Murine central neurons express a novel member of the cdc10/SWI6 motif-containing protein superfamily.

V-1 protein is a novel member of the cdc10/SWI6 motif-containing protein superfamily several members of which have been demonstrated to play crucial roles in the regulation of intracellular signaling. In the present study we examined the distribution of V-1 mRNA in the murine central nervous system (CNS). Northern analysis revealed the expression of V-1 mRNA in various regions of the brain with the following rank order: hippocampus, cerebellum > cerebral cortex, olfactory bulb, medulla oblongata, pons > thalamus. In situ hybridization also showed that V-1 mRNA is widely distributed in various regions of the brain, with parallel expression levels to those revealed by Northern analysis. Immunohistochemical analysis revealed that the V-1 protein exists in various types of neurons, mainly in cell bodies but also in dendrites, axons and possibly in synaptic areas. These expression patterns of the V-1 gene in the murine CNS suggest that the V-1 protein performs some common function in different classes of neurons. We found no significant difference in the expression level of V-1 mRNA in cerebellar granule cells between the control and mutant mice of Purkinje cell degeneration (pcd). In comparison with our previous data obtained in another mutant, staggerer, we discussed the effects of target deprivation on the expression of V-1 mRNA in cerebellar granule cells.

Animals↗

Common occurrence of an antiidiotypic antibody that recognizes T14+ anti-DNA antibodies in patients with systemic lupus erythematosus.

OBJECTIVE: To investigate whether antibodies to a T14 anti-DNA antibody can be found in patients with systemic lupus erythematosus (SLE). METHODS: Seventy-six serum samples (37 from patients with SLE) were randomly selected from among sera submitted for routine antinuclear antibody testing. Short, overlapping peptides based on the partial VH (variable region of the heavy chain) sequence of the T14 antibody were synthesized on multipins and screened for reactivity with SLE sera. In addition, selected peptides from T14 and related proteins were synthesized in bulk and screened for reactivity with both SLE and control sera. A monoclonal antibody was generated to determine the prevalence of the T14 idiotype (T14+ Id) in the different study populations. RESULTS: Antibodies were detected by a peptide based on the third complementarity-determining region (CDR3) of the T14 protein in 15 (41%) of 37 patients with SLE or 15 (54%) of 28 who had anti-DNA antibodies, in 3 (9%) of 34 patients without anti-DNA antibodies (9 of whom had SLE), and in 6 (10%) of 57 healthy controls. In SLE sera, the antiidiotypic (anti-Id) responses (IgM and IgG) correlated well with the anti-DNA responses (IgG), and both responses correlated well with the T14+ Id activity in SLE sera. Control peptides based on the 18/2 (16/6+ Id) and S107 proteins detected low antibody activities in SLE sera, attributable to cross-reactivity with the T14 peptide. A peptide based on an unrelated human antibody was not reactive with these sera. CONCLUSION: Anti-Id antibodies directed to T14 VHCDR3 were found commonly in the sera of patients with SLE, and they appeared to be induced by the anti-DNA antibodies present in the sera. Based on these findings, these secondary antibodies may be pathogenic in SLE.

Adolescent↗

Increased level of neurokinin-1 tachykinin receptor gene expression during early postnatal development of rat brain.

Substance P is known to elicit diverse actions via activating multiple subtypes of tachykinin receptors, and these actions appear to be involved not only in synaptic transmission but also in synaptic plasticity during development of the mammalian central nervous system. The availability of sensitive quantitation of individual tachykinin receptor subtypes is crucial for elucidating the physiological function specifically mediated by activation of a particular receptor subtype. We thus attempted to develop an assay to determine the level of messenger RNA molecule encoding the neurokinin-1-type tachykinin receptor and apply it for assessment of developmental changes in the neurokinin-1 receptor gene expression in the rat brain to explore the role of tachykinin receptors during ontogeny. The assay was designed to use a competitive reverse transcription-polymerase chain reaction co-amplifying endogenous neurokinin-1 receptor messenger RNA and internal standard, which enabled specific quantification of the number of neurokinin-1 receptor transcripts, ranging from 3.1 x 10(3) to 1.3 x 10(5) molecules/microgram total RNA. The levels of neurokinin-1 receptor gene expression were examined in three different brain regions of the rat aged 0-56 days after birth. The order of neurokinin-1 receptor messenger RNA expression was hippocampus > cerebral cortex > > cerebellum at all ages examined except postnatal day 0, where its expression was more abundant in the cerebral cortex than in the hippocampus. From postnatal day 3 onward, the hippocampus contained 140-160% of the cortical levels. Although the tachykinin receptor expression in the cerebellum was too low to be accurately assessed by conventional techniques, our assay enabled us to determine the amount of cerebellar neurokinin-1 receptor messenger RNA that changed in the range 7-23% of the cortical level during postnatal development. A prominent feature revealed by this assay is that the neurokinin-1 receptor gene expression in the rat brain is developmentally regulated. The hippocampus displayed a transient peak of neurokinin-1 receptor messenger RNA at postnatal day 3 and a subsequent gradual decrease. In the cerebral cortex, the amount of the message was highest at birth, and was followed by a moderate decrease during postnatal development. At 56 days after birth, the expression levels in both brain regions were down-regulated to approximately 50% of their maximal levels. The transitory pattern of gene expression was also observed in the cerebellum. The results of this study demonstrate that the reverse transcription-polymerase chain reaction-based assay is useful to quantitate precisely the neurokinin-1 tachykinin receptor message in limited tissue samples derived from discrete brain regions. Together with previous findings, the increased level of neurokinin-1 receptor messenger RNA expression in immature rat brain shown by the present analysis suggests that the neurokinin-1-type tachykinin receptor may play a role in the synaptic plasticity associated with morphological and functional development of the mammalian CNS.

Aging↗

Tri-amelia and phocomelia with multiple malformations resembling Roberts syndrome in a fetus: is it a variant or a new syndrome?

Roberts-SC phocomelia syndrome is a rare autosomal recessive disorder characterized by morphological anomalies such as limb defects and midfacial clefting, and by premature centromeric division in chromosomal study. Although it has been regarded as a single genetic entity and includes various morphologic defects, babies are being reported nowadays with severe facial defects, tetra-amelia, and pulmonary abnormality, yet with normal chromosomal findings. We have added a case resembling Roberts syndrome with various congenital anomalies. A gestation with a fetus was terminated at 24 weeks of gestational age because of multiple fetal anomalies. Postmortem examination revealed a severe mid-facial cleft, tri-amelia and phocomelia, multiple encephaloceles, protruding and hypoteloric eyes, low-set ears, atrial septal defect of ostium secundum type, patent ductus arteriosus, bilateral two-lobed lungs with incomplete lobation, multiple visceral anomalies, a penis without scrotum, abnormal dermoglyphics, and absence of nipples.

Abnormalities, Multiple↗

Changes in the gene expression of a protein with the cdc10/SWI6 motif, V-1, during rat follicular development and corpus luteum formation.

We examined the gene expression of V-1, a novel soluble protein with the cdc10/SWI6 motif, in pseudopregnant rat ovaries. Northern blot analysis on days 1, 5, and 11 of pseudopregnancy revealed an approximately 2-fold increase in the V-1 messenger RNA (mRNA) expression level on day 5 to that on day 1, and no significant change was observed between those on day 5 and day 11. An injection of human CG on days 5 further increased th V-1 mRNA level to about 1.6-fold of that of the untreated control. Western blot analysis showed higher V-1 protein expression on days 5 and 11 of pseudopregnancy than that on day 1. In situ hybridization and immunohistochemistry with ovaries on day 3 of pseudopregnancy showed that luteal cells of corpora lutea and also cells of the coexisting follicles including oocytes express V-1 mRNA and the protein, with apparent rank order of the expression: oocytes > luteal cells > follicular cells >> atretic follicular cells including oocytes. These data indicate the dynamic change in the V-1 gene expression in the ovarian steroidogenic cells and oocytes and suggest potential roles of the V-1 protein in ovarian functions including corpus luteum formation and folliculogenesis.

Animals↗

p53 protein expression in extrahepatic bile duct cancer.

p53 mutations, a tumor suppressor gene located on chromosome 17p, are the most common genetic alterations found in human cancers. Although the p53 expression or mutation has been investigated in a variety of cancers there have been very few studies in extrahepatic bile duct cancers. In this study, we investigated the immunohistochemical expression of p53 in formalin fixed paraffin embedded archival specimens of 36 extrahepatic bile duct cancers in which p53 expression was found in eighteen (50%) cases. There was no significant difference in age, gender, size of tumor, histologic grade, extent of tumor involvement, lymph node metastasis and tumor resectability according to p53 immunoreactivity. Comparison of survival duration according to p53 expression showed no significant difference. In conclusion, we reported 50 percent of p53 expression in extrahepatic bile duct cancers by immunohistochemical staining and we found no prognostic significance of p53 expression in dinicopathologic parameters.

Adult↗

Evaluation of therapeutic regimens for the treatment of Helicobacter pylori infection.

Helicobacter pylori (H. pylori) is currently considered the most important exogenous factor in the genesis of gastritis and peptic ulcer disease. However, the optimum regimen for the eradication of H. pylori remains unclear. The purpose of this study was to evaluate the eradication rate of H. pylori, the side effects, and the patients' compliance with regard to various drug regimens. We also analyzed factors influencing the eradication of H. pylori. One hundred and eighty patients were included and divided into four groups: 42 patients (Group I) received tripotassium dicitrato bismuthate (240 mg b.i.d.), metronidazole (250 mg t.i.d.) and amoxicillin (500 mg t.i.d.) for 14 days; 55 patients (Group 2) received omeprazole (20 mg b.i.d.) and amoxicillin (1000 mg b.i.d.) for 14 days; 36 patients (Group 3) were treated with omeprazole (20 mg b.i.d.), metronidazole (250 mg t.i.d.) and amoxicillin (500 mg t.i.d.) for 14 days; and 47 patients (Group 4) received omeprazole (20 mg q.d.) and amoxicillin (500 mg t.i.d.) for 14 days and then tripotassium dicitrato bismuthate (240 mg b.i.d.) and nizatidine (150 mg q.d.) for 14 days. The diagnosis of H. pylori was made by histology. The eradication of H. pylori was defined both by histology (H&E and Giemsa stain) and by rapid urease test (CLOR) showing negative for H. pylori 4 weeks after the completion of therapy. Of the 180 patients, 95 patients had non-ulcer dyspepsia, 40 patients had gastric ulcer and 45 patients had duodenal ulcer. The eradication rate of H. pylori was highest (89.3%) in Group 3, as compared with Group 1 (68.9%), Group 2 (65.4%), and Group 4 (48.9%). The eradication rate was significantly higher in Group 3 than in Groups 2 and 4 (p < 0.05). There was no significant difference in the eradication rate among clinical diagnosis, sex and age. But, in the conventional triple therapy (Group 1), the eradication rate was higher in male (78.6%) than in female (46.2%). The side effects in order, were nausea (22.1%), dizziness (19.5%), abdominal pain (11.6%) and diarrhea (97%), and there was no difference among the drug regimens. The compliance of the patients was good (more than 80% irrespective of drug regimen). On the basis of these findings, the side effects of the drugs seemed minimal, and the compliance of patients was good irrespective of the drug regimen. In conclusion, the triple therapy with omeprazole, metronidazole and amoxicillin was the most effective regimen and could be recommended for H. pylori eradication.

Adult↗

Prediction of tumor response to experimental radioimmunotherapy with 90Y in nude mice.

PURPOSE: To identify those factors that predict variability in tumor response to 90Y-radioimmunotherapy based on measurement of incorporated activity and physical dimensions of individual tumors and to apply the concept of effective dose to radioimmunotherapy. METHODS AND MATERIALS: Human colon carcinoma xenografts growing in nude mice were treated with anti-CEA antibodies labeled with 90Y directly or through a bispecific antibody/labeled hapten system. Tumor response was measured as the delay in growth to eight times the treatment volume. Noninvasive activity (based on bremsstrahlung radiation) and dimension measurements were made in these animals at several times after label injection. The following parameters were compared for their ability to predict individual tumor response: (a) injected activity, (b) injected activity times a factor based on average uptake as a function of volume, (c) in vivo activity per volume measured in each animal at a single time, (d) the integral over time of in vivo activity per volume in each animal, and (e) the minimum dose for each animal in a uniformly active ellipsoid whose total activity and dimensions varied over time the same as the tumor. RESULTS AND CONCLUSION: After correcting for differences in injected activity, two parameters account for much of the variability in tumor response. One of these is the general trend of larger tumors to take up less activity per volume. Additional variability can be accounted for by the in vivo activity per volume measurements. The minimum dose as introduced here is likely to be useful in estimating the biologically effective dose delivered by each treatment.

Animals↗

Identification of cell binding sites in the laminin alpha 1 chain carboxyl-terminal globular domain by systematic screening of synthetic peptides.

The laminin alpha 1 chain carboxyl-terminal globular domain has been identified as a site of multiple biological activities. Using a systematic screening for cell binding sites with 113 overlapping synthetic peptide beads that covered this domain, we found 19 potential active sequences. Corresponding synthetic peptides were evaluated for direct cell attachment, spreading, and inhibition of cell spreading to a laminin-1 substrate using several cell lines. Five peptides (AG-10, AG-22, AG-32, AG-56, and AG-73) showed cell attachment activities with cell-type specificities. Cell spreading on AG-10 was inhibited by beta 1 and alpha 6 integrin antibodies and on AG-32 was inhibited by beta 1, alpha 2, and alpha 6 integrin antibodies. In contrast, cell adhesion and spreading on peptide AG-73 were not inhibited by these antibodies. The minimum active sequences of AG-10, AG-32, and AG-73 were determined to be SIYITRF, IAFQRN, and LQVQLSIR, respectively. These sequences are highly conserved among the different species and different laminin alpha chains, suggesting that they play a critical role for biological function and for interaction with cell surface receptors.

Amino Acid Sequence↗

A nuclear factor containing the leucine-rich repeats expressed in murine cerebellar neurons.

A nuclear protein, termed leucine-rich acidic nuclear protein (LANP), has been isolated from among rat cerebellar proteins whose expression was transiently increased during an early stage of postnatal development. The amino acid sequence, deduced from its cDNA, showed that LANP contains 247 amino acids consisting of two distinct structural domains: the N-terminal domain characterized by "leucine-rich repeat," which is found in many eukaryotic proteins and which potentially functions in mediating protein-protein interactions, and the C-terminal domain characterized by a cluster of acidic amino acids with a putative nuclear localization signal. Immunohistochemical study using an antibody against LANP revealed that the protein is localized mainly in nuclei of Purkinje cells. In the rat cerebellum on postnatal day 7, LANP mRNA was expressed moderately in the external granule and Purkinje cells and weakly in the internal granule cells. The expression in these cells, especially in Purkinje cells, increased in the second postnatal week and thereafter decreased to an adult level. The structural characteristics, localization, and the stage- and cell type-specific expression suggest a potential role of LANP in a signal transduction pathway that directs differentiation of cerebellar neurons.

Aging↗

Enhancement by serotonin of GABA-mediated inhibitory synaptic currents in rat cerebellar Purkinje cells.

The actions of serotonin (5-HT) on synaptic responses in Purkinje cells were examined using the whole-cell voltage-clamp recording from thin slices of the rat cerebellum. Focal stimulation within the molecular layer elicited synaptic responses: (1) inhibitory postsynaptic currents (IPSCs) that were completely blocked by bicuculline; (2) excitatory postsynaptic currents (EPSCs) that were antagonized by CNQX; and (3) combination of IPSC and EPSC. Application of 5-HT (3-30 microM) increased the amplitude of the stimulation-evoked IPSCs but did not significantly affect the EPSCs. The frequency and the mean amplitude of spontaneous IPSCs were increased in the presence of 5-HT. Neither the sensitivity to exogenously applied GABA nor the holding current of Purkinje cells were noticeably altered by 5-HT. The results indicate that 5-HT differentially enhances the GABA-mediated IPSCs in rat cerebellar Purkinje cells via a presynaptic mechanism. Serotonergic neurons thus appear to play a role in the motor control through selective presynaptic facilitation that modulates the output from the cerebellar cortex.

6-Cyano-7-nitroquinoxaline-2,3-dione↗