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Biomedical subjects

S R Kim

Publications and source records attributed to S R Kim.

At least 19 recordsLinked to original sources
PubMed2005

Four-dimensional ultrasound guidance of prenatal invasive procedures.

OBJECTIVE: Technological advances in ultrasonography have revolutionized prenatal diagnosis and treatment. Here we evaluate the effectiveness of using four-dimensional (4D) ultrasonography to guide prenatal invasive procedures. PATIENTS AND METHODS: Prenatal invasive procedures using 4D ultrasound were recorded prospectively in 93 cases: 10 amnioinfusions, 50 amniocenteses, 8 chorionic villus samplings (CVS) and 25 cordocenteses. The needle target site was first identified using the two-dimensional (2D) mode, and was then confirmed using the three-dimensional (3D) mode. The needle was inserted under 4D ultrasound guidance. After selecting the needle target site, the true position of the needle was determined in three planes ('real-time 3D targeting'). RESULTS: Using 4D ultrasound guidance, most procedures were performed within 5 min and with a 100% success rate, even in cases involving severe oligohydramnios (amniocentesis), thin placentas (CVS) or narrow umbilical veins (cordocentesis). Moreover, there were no serious complications during or after any procedure. CONCLUSIONS: 4D ultrasonography can be used to guide various prenatal invasive procedures offering clear information in all three planes. It is likely that such imaging will reduce the time taken to complete the procedures and reduce the risks associated with them. Published by John Wiley & Sons, Ltd.

Adult↗
PubMed2005

Identification and molecular characterization of a prophenoloxidase involved in Aedes aegypti chorion melanization.

Chorion melanization is a vital biochemical event for the survival of mosquito eggs in the environment. This study describes the identification and molecular characterization of a prophenoloxidase (proPO) involved in chorion melanization in Aedes aegypti by various biochemical and molecular techniques. Results revealed that transcription of the chorion proPO occurs only in adults, blood feeding greatly stimulated its transcription and haemocytes are responsible for its transcription. Our study provides a solid basis for suggesting an essential role of the isolated proPO in chorion melanization during chorion hardening and also raises fundamental questions regarding its transportation and distribution in the chorion. This study should serve as a useful reference towards functional elucidation of other proPOs in mosquitoes.

Aedes↗
PubMed2005

Interferon-beta induction/interferon-alpha2b plus ribavirin therapy in patients with chronic hepatitis C.

Treatment of chronic hepatitis C virus (HCV) infection with interferon (IFN) and ribavirin improves the rate of eradication of the virus by less than 20% in patients with genotype 1b and a high viral load. In this study we assessed whether IFN-beta induction/IFN-alpha2b plus ribavirin enhances the efficacy of the therapy in patients with chronic hepatitis C. The efficacy of IFN-beta induction/IFN-alpha2b plus ribavirin therapy (group A, n=7) was compared with that of IFN-alpha2b plus ribavirin (group B, n=7) in 14 patients with high levels of HCV-RNA (> 100 K/U/ml). No significant differences were observed in the clearance of HCV-RNA between the two groups (A and B, respectively) 2 weeks after the start of the treatment (0% and 14.3%), at the end of the treatment (71.4% and 100%) and 6 months after the end of the treatment (28.6% and 14.3%). Recovery was complete in 28.6% and 14.3%, transient in 42.9% and 85.7% and absent in 28.6% and 0% in groups A and B, respectively. Early log changes in the viral load from the baseline after 2 weeks of treatment were 2.41 +/- 0.91 and 2.77 +/- 0.20 in groups A and B, respectively, with no significant difference between the two groups. In the present study, we were not able to demonstrate that IFN-beta induction/IFN-alpha2b plus ribavirin therapy was superior to IFN-alpha2b plus ribavirin therapy in patients with genotype 1b and high viral loads.

Adult↗
PubMed2004

Emotion recognition system using short-term monitoring of physiological signals.

A physiological signal-based emotion recognition system is reported. The system was developed to operate as a user-independent system, based on physiological signal databases obtained from multiple subjects. The input signals were electrocardiogram, skin temperature variation and electrodermal activity, all of which were acquired without much discomfort from the body surface, and can reflect the influence of emotion on the autonomic nervous system. The system consisted of preprocessing, feature extraction and pattern classification stages. Preprocessing and feature extraction methods were devised so that emotion-specific characteristics could be extracted from short-segment signals. Although the features were carefully extracted, their distribution formed a classification problem, with large overlap among clusters and large variance within clusters. A support vector machine was adopted as a pattern classifier to resolve this difficulty. Correct-classification ratios for 50 subjects were 78.4% and 61.8%, for the recognition of three and four categories, respectively.

Autonomic Nervous System↗
PubMed2004

The effect of divalent metal ions on the zeta potential of bubbles.

Micro-bubbles are used in electro-flotation (EF) and dissolved air flotation (DAF) for particle separation. The efficiency of these flotation processes depends on the collision of bubble and particle and the collision efficiency is affected by certain parameters with respect to the size and zeta potential of bubble and particle. Therefore, it is necessary to monitor not only the zeta potential of the particle, but also that of the bubble. Gas bubbles are reported to be generally negatively charged in water. In this paper, we report a study performed to measure the zeta potential of bubbles in solutions containing divalent metals and find factors which can produce positively charged bubbles. Calcium and magnesium ions were selected as divalent metal ions because natural water normally contains an appreciable quantity of them. It was found that bubbles are negatively charged in CaCl2 solutions whereas, under certain conditions, they become positively charged in MgCl2. Charge reversal of bubbles was observed above 10(-2) M Mg, especially above pH 9. A probable principle that explained the charge reversal could be a combined mechanism with both specific adsorption of hydroxylated species and formation of hydroxide precipitates. Creating solution conditions that can produce positively charged bubbles in flotation methods might make it possible to remove particles using lesser amounts of coagulant or even none at all.

Air↗
PubMed2003

Synthesis of Si, Mg substituted hydroxyapatites and their sintering behaviors.

Si, Mg-substituted hydroxyapatites, alone and co-substituted, have been prepared to obtain biomaterials having an improved biocompatibility. From FT-IR, XRD and ICP analyses, it was confirmed that single phases of hydroxyapatite substituted by Si alone or co-substituted by Si, Mg. The XRD data indicated the absence of extra phases related to silicon and magnesium oxide or other calcium phosphate species. Si-substituted hydroxyapatite of up to 2 wt% for Si and Si, Mg co-substituted hydroxyapatite of 1 wt% for the each ion keep their original structures intact for the sintering temperatures of up to 1200 degrees C. However, it is observed that ion substitutions by an amount higher than the above ratios for each hydroxyapatite lead to destabilization of original structures of the hydroxyapatite and to the production of tricalcium phosphate and calcium phosphate silicate phases when the samples were sintered at 1100 degrees C or higher.

Biocompatible Materials↗
PubMed2003

Pathologic characteristics of prostatic adenocarcinomas: a mapping analysis of Korean patients.

Pathologic characteristics of the prostatic adenocarcinoma in Koreans are not clear. We studied 132 cases of prostatectomy specimens using mapping analysis to discover the pathologic characteristics of the Korean prostatic adenocarcinoma. Mean values were as follows: serum prostate-specific antigen level (sPSA), 16.4 ng/ml; tumor volume, 27.5%; size, 2.4 cm; Gleason score, 7.7; and p53 expression, 9.8%. Rates of multifocal tumors and high-grade prostatic intraepithelial neoplasm (HPIN) were 33.3 and 65.2%. The Gleason score, tumor volume%, tumor size and sPSA were correlated with each other. Korean prostatic adenocarcinomas showed higher Gleason scores, lower rates of HPIN and multifocality, and lower p53 expression in comparison to Western prostatic adenocarcinomas. These data may be a basis for pathologic characteristics of Korean prostatic adenocarcinoma that has now been increasing.

Adenocarcinoma↗
PubMed2002

Assessment of the disturbances in metabolic homeostasis: a hypothesis of synergism.

Based on the hypothesis that a synergistic interaction between triiodothyronine (T(3)) and insulin contributes to abnormalities in glucose and other metabolic pathways, the mechanisms underlying the impairment of metabolic homeostasis (MH) and the development of type-2 diabetes (DM) were investigated via a proposed homeostatic model, [(FG*TG)/T3*FI)]. The MH model characterizes the relationship between T(3) and insulin and the levels of triglycerides (TG), fasting insulin (FI), and fasting glucose (FG) and is introduced as a clinical method to assess insulin sensitivity and the status of metabolic homeostasis in lieu of current screening models advocated by the by American Diabetic Association (ADA). The present study validated the hypothetical model in a sample of 110 African-American women.

Black or African American↗
PubMed2002

A hypothesis of synergism: the interrelationship of T3 and insulin to disturbances in metabolic homeostasis.

While the role of abnormal insulin homeostasis in the pathogenesis of Type-2 diabetes mellitus is well established, the importance of the canonical role of T(3) on Type-2 diabetes or the homeostasis of glucose, lipid, and energy balance has not been addressed. Based on the available evidence from molecular biology, the pivotal regulatory role of T(3) in major metabolic pathways and glycemic control can be delineated by mapping the specific action sites of T(3) and insulin on the metabolic pathways of the glucose-lipid cycle. The current paper presents an integrative hypothesis of the synergistic relationship of T(3) and insulin in metabolic homeostasis and abnormalities.

GTP-Binding Proteins↗
PubMed2001

Constitutive expression of rice MADS box gene using seed explants in hot pepper (Capsicum annuum L.).

Two transgenic pepper plants were obtained from 255 seed explants that were infected with Agrobacterium LBA4404 (pGA1209). One of them (PT2) showed morphological change, such as dwarfism and early flowering by the constitutive expression of the rice OsMADS1 gene. The in vitro condition of the plant regeneration has been optimized from hypocotyl explants on a MS medium that was supplemented with zeatin 3 mg/L, IAA 0.3 mg/L for shoot induction. The optimal rooting condition was at NAA 0.3 mg/L. The transformation frequency was 0.8% from the total hypocotyls. DNA and RNA hybridization analyses showed that the introduced gene was integrated and stably expressed in regenerated plants.

Capsicum↗
PubMed2001

N-terminal processing is essential for release of epithin, a mouse type II membrane serine protease.

Epithin was originally identified as a mouse type II membrane serine protease. Its human orthologue membrane type-serine protease 1 (MT-SP1)/matriptase has been reported to be localized on the plasma membrane. In addition, soluble forms of matriptase were isolated from human breast milk and breast cancer cell-conditioned medium. In this paper, we report a processing mechanism that appears to be required for the release of epithin. CHO-K1 or COS7 cells transfected with single full-length epithin cDNA generated two different-sized proteins in cell lysates, 110 and 92 kDa. The 92-kDa epithin was found to be an N-terminally truncated form of the 110-kDa epithin, and it was the only form detected in the culture medium. The 92-kDa epithin was also found on the cell surface, where it was anchored by the N-terminal fragment. The results of in vivo cell labeling experiments indicate that the 110-kDa epithin is rapidly processed to the 92-kDa epithin. Using site-directed mutagenesis experiments, we identified Gly(149) of the GSVIA sequence in epithin as required for the processing and release of the protein. These results suggest that N-terminal processing of epithin at Gly(149) is a necessary prerequisite step for release of the protein.

Animals↗
PubMed2001

Production and characterization of monoclonal antibodies against amphiphysins.

Amphiphysin I and II, proteins enriched in nerve terminals, form heterodimers and interact with dynamin and synaptojanin through their Src homology 3 (SH3) domain. In order to study the expression profile of Amphs in cells and tissues and the interaction state with other cellular molecules, we have prepared specific monoclonal antibodies (mAbs) designed to bait N-terminus, middle part, and C-terminus domains of Amph I, respectively by immunizing with the expressed smaller domain molecules using the GST gene fusion system. The expression of Amphs was found to be most abundant in PC12 cells, followed by B103 cells and vascular smooth muscle cells. Western blot analysis showed a relatively high level expression of Amphs that were found in both mouse and rat brain. There appeared to be some species difference in the expression pattern, i.e. Amphs are present more in the testis than in the lungs in rats, however, they are reversed in mice. Characterization of the mAbs revealed that clone 14-23 precipitated Amph I and II, whereas clone 8-2 could only precipitate Amph I. In addition, clathrin and dynamin in a complex with Amph were captured in the precipitate formed by mAbs and identified by the Western blot analysis. Cellular distribution of Amph was visualized with confocal immunofluorescence microscopy performed using the labeled-mAbs. Taken together, these results demonstrated that mAbs provided an excellent measure for studying Amphs' expression profile and their interacting proteins.

Animals↗
PubMed2001

Molecular cloning of the anther-preferential nonspecific lipid transfer protein cDNA in hot pepper by mRNA differential display.

To better understand the molecular control of anther development, an anther-preferential mRNA was isolated from hot pepper (Capsicum annuum) using mRNA differentially display. Using the displayed fragment as a probe, a full-length cDNA named CaLTP was isolated. A nucleotide sequence analysis of CaLTP revealed that the clone contains an open reading frame of 123 amino acids, which exhibits a 60-23% identity with nonspecific lipid transfer proteins (nsLTP). Northern and RT-PCR analysis of the clone confirmed that CaLTP mRNA was predominant to anther tissues. The basal expression level in the leaves was slightly induced only by abscisic acid (ABA) treatment. Southern analysis reveals that CaLTP is present as a single-copy gene in hot pepper genome. We hypothesize that CaLTP might have an important role in protecting the reproductive tissues from environmental stresses.

Amino Acid Sequence↗
PubMed2001

Ten-year survival of patients with locally advanced, stage ib-iib cervical cancer after neoadjuvant chemotherapy and radical hysterectomy.

OBJECTIVE(S): The aim of this study was to evaluate the effects of neoadjuvant chemotherapy and radical hysterectomy on long-term survival in stage IB-IIB locally advanced cervical cancer by conducting a 10-year follow-up. METHODS: Between August 1983 and May 1990, 80 locally advanced, stage IB-IIB cervical cancer patients with tumor diameter greater than or equal to 4 cm were treated with neoadjuvant VBP chemotherapy (cisplatin, vinblastine, and bleomycin) followed by radical hysterectomy with pelvic lymphadenectomy. After this therapeutic modality, patients were followed for more than 10 years. Ten-year survival rates and factors affecting recurrence after this therapy were evaluated. RESULTS: Of 80 patients, 75 (93.7%) showed a reduction in tumor size after neoadjuvant chemotherapy. At pathologic examination, stage reduction was noted in 53 (66.2%) patients and 20 patients (25%) showed no residual or microinvasive cervical tumor. Pelvic lymph node metastases were found in 17 patients (21.3%). During the 10-year follow up, 2 patients were lost and 16 patients recurred. Overall 5-year and 10-year disease-free actual survival rates were 82.0 (64/78) and 79.4% (62/78), respectively. Clinical stage, initial tumor size, clinical response, and residual tumor size were not risk factors for recurrence after this therapy. However, pelvic lymph node metastasis was a significant risk factor for recurrence. CONCLUSION(S): Neoadjuvant VBP chemotherapy followed by radical hysterectomy in locally advanced, stage IB-IIB cervical cancer patients seemed to improve the long-term survival rate for these patients compared to that of conventional therapy. However, randomized controlled trials are needed to confirm this result.

Adenocarcinoma↗
PubMed2001

Roles of chromosomal and episomal dinB genes encoding DNA pol IV in targeted and untargeted mutagenesis in Escherichia coli.

DNA polymerase IV (pol IV) in Escherichia coli is a member of a novel family of DNA polymerases (the DinB/UmuC/Rad30/Rev1 super-family or the DNA polymerase Y family). Although expression of the dinB gene encoding DNA pol IV is known to result in an enhancement of untargeted mutagenesis, it remains uncertain whether DNA pol IV is involved in a variety of lesion-induced mutagenesis (targeted mutagenesis), and the relationship between expression levels of dinB and the mutagenesis that DNA pol IV promotes has not been investigated thoroughly. Here, we report that DNA pol IV is involved in -1 frameshift mutagenesis induced by 4-nitroquinoline N-oxide (4-NQO) and that the expression level of the chromosomal pol IV gene is 6-12 times higher than those for other SOS-inducible DNA polymerases in E. coli, i.e., DNA pol II (PolB) or DNA pol V (UmuDC), respectively. Interestingly, the dinB gene is present not only on the chromosome but also on the F' plasmid in the E. coli CC108 strain. In this strain, 750 molecules of DNA pol IV are expressed from the F' dinB gene in the uninduced state and 250 molecules are expressed from the chromosomal gene. These cellular expression levels strongly affect -1 frameshifts induced by 4-NQO in runs of six guanine bases: mutagenicity was highest in the strain CC108, followed by strains YG2242 (chromosome deltadinB/F' dinB+), YG2247 (chromosome dinB+/F' deltadinB) and FC1243 (chromosome deltadinB/F' deltadinB). The incidence of untargeted -1 frameshifts was reduced by two-thirds on deletion of dinB from the F' episome. The chromosomal dinB gene appeared to have little or no effect on the untargeted mutagenesis. These results suggest that DNA pol IV efficiently mediates targeted mutagenesis by 4-NQO, and that the cellular levels of expression substantially affect targeted and untargeted mutagenesis.

4-Nitroquinoline-1-oxide↗
PubMed2001

Neuroprotective constituents from Hedyotis diffusa.

In a bioassay-guided search for neuroprotective compounds from medicinal plants, a MeOH extract of whole plants of Hedoytis diffusa yielded five flavonol glycosides, kaempferol 3-O-[2-O-(6-O-E-feruloyl)-beta-D-glucopyranosyl]-beta-D-galactopyranoside (1), quercetin 3-O-[2-O-(6-O-E-feruloyl)-beta-D-glucopyranosyl]-beta-D-galactopyranoside (2), quercetin 3-O-[2-O-(6-O-E-feruloyl)-beta-D-glucopyranosyl]-beta-D-glucopyranoside (3), kaempferol 3-O-(2-O-beta-D-glucopyranosyl)-beta-D-galactopyranoside (4), and quercetin 3-O-(2-O-beta-D-glucopyranosyl)-beta-D-galactopyranoside (5), and four O-acylated iridoid glycosides (6-9). Compounds 1 and 2 are previously unreported natural products, and all nine compounds exhibited significant neuroprotective activity in primary cultures of rat cortical cells damaged by L-glutamate.

Animals↗
PubMed2001

Analysis of steroid-induced genes in the rat preoptic area-anterior hypothalamus using a differential-display reverse transcriptase-polymerase chain reaction.

Steroid hormones modulate a variety of physiological functions in the hypothalamus. We attempted to identify steroid-regulated genes in the rat preoptic area-anterior hypothalamus by comparing differentially expressed mRNAs. Adult female rats were ovariectomized and, 1 week later, a silastic capsule containing 17beta-oestradiol (180 microg/ml) was subcutaneously implanted. After 2 days, a single injection of progesterone (1 mg) was administered at 10.00 h and rats were killed at 17.00 h on the same day. Differential-display polymerase chain reaction followed by Northern blot analysis showed that 10 clones were differentially regulated. Using homology search in Genbank, three genes were identified as sodium, potassium-ATPase beta1, protein kinase C-binding Nell-homologue protein and evectin-1. Further characterization of 10 clones showed that the expression patterns were tissue-specific and differentially regulated during puberty. Among these, mRNAs for protein kinase C-binding Nell-homologue protein, evectin-1 and human CGI-118 protein-like gene were induced after vagina opening, and differentially expressed during the oestrous cycle. Taken together, several steroid-regulated genes identified in the present study may play an important role in regulating hypothalamic functions, including puberty and the oestrous cycle.

Animals↗