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Biomedical subjects

H Y Kim

Publications and source records attributed to H Y Kim.

At least 19 recordsLinked to original sources

Amphiphilic triblock copolymer poly(p-dioxanone-co-L-lactide)-block-poly(ethylene glycol), enhancement of gene expression and inhibition of lung metastasis by aerosol delivery.

We describe the development of an aerosol system for topical gene delivery to the lungs of C57BL/6 mice. This system is based on the combination of the commercial cationic lipid Lipofectin with a novel amphiphilic triblock copolymer, poly(p-dioxanone-co-L-lactide)-block-poly(ethylene glycol) (PPDO/PLLA-b-PEG, and abbreviated in the text as polymeric micelles). After optimizing conditions for DNA delivery to the lungs of mice using the combination of polymeric micelles with Lipofectin and LacZ DNA, we used the Lipofectin/polymeric micelle system to deliver the tumor suppressor gene PTEN to the lungs of C57BL/6 mice bearing the B16-F10 melanoma. Lipofectin/PTEN/polymeric micelles significantly improved gene expression of PTEN in the lungs of mice with no evidence of cell toxicity or acute inflammation. Importantly, lung metastasis, as measured by lung weight, was significantly reduced (P<0.001), as were total tumor foci in the lungs (P<0.001) and size of individual tumor nodules in animals treated with Lipofectin/PTEN/polymeric micelles compared with control animals. Survival time was also extended. These results suggest that the Lipofectin/polymeric micelle system is appropriate for enhancing gene delivery in vivo and that it can be applied as a non-invasive gene therapy for lung cancer.

Aerosols↗

Relationship between omega-3 fatty acids and plasma neuroactive steroids in alcoholism, depression and controls.

Deficiency in the long-chain omega-3 fatty acid, docosahexaenoic acid (DHA) has been associated with increased corticotropin releasing hormone and may contribute to hypothalamic pituitary axis (HPA) hyperactivity. Elevated levels of the neuroactive steroids, allopregnanolone (3alpha,5alpha-THP) and 3alpha,5alpha-tetrahydrodeoxycorticosterone (THDOC) appear to counter-regulate HPA hyperactivity. Plasma essential fatty acids and neurosteroids were assessed among 18 male healthy controls and among 34 male psychiatric patients with DSM-III alcoholism, depression, or both. Among all subjects, lower plasma DHA was correlated with higher plasma THDOC (r = -0.3, P < 0.05) and dihydroprogesterone (DHP) (r = -0.52, P < 0.05). Among psychiatric patients lower DHA was correlated with higher DHP (r = -0.60, P < 0.01), and among healthy controls lower plasma DHA was correlated with higher THDOC (r = -0.83, P < 0.01) and higher isopregnanolone (3beta,5alpha-THP) (r = -0.55, P < 0.05). In this pilot observational study, lower long-chain omega-3 essential fatty acid status was associated with higher neuroactive steroid concentrations, possibly indicating increased feedback inhibition of the HPA axis.

Alcoholism↗

Serum adiponectin, interleukin-10 levels and inflammatory markers in the metabolic syndrome.

We examined the association between interleukin-10 (IL-10), adiponectin levels and inflammatory markers such as interleukin-6 (IL-6) and high-sensitive C-reactive protein (hsCRP). Furthermore, the association of these anti-/pro-inflammatory cytokine levels with the metabolic syndrome was investigated. The study subjects were composed of 312 Korean individuals without diabetes. Serum adiponectin level was associated with hsCRP (r=-0.21, P<0.001), IL-6 (r=-0.13, P<0.05) and IL-10 (r=-0.22, P<0.001) levels. Subjects without the metabolic syndrome showed higher adiponectin (17.03 microg/ml versus 13.85 microg/ml, P<0.001) and IL-10 (4.74 pg/ml versus 4.34 pg/ml, P=0.014) levels, and lower serum hsCRP (0.38 microg/ml versus 0.66 microg/ml, P=0.001) and IL-6 (0.94 pg/ml versus 1.32 pg/ml, P=0.009) levels compared to those with the metabolic syndrome. In multiple logistic regression analysis, the metabolic syndrome was associated with sex, age, waist circumference, systolic blood pressure, HDL cholesterol, triglyceride, fasting blood glucose and interleukin-10. Furthermore, serum adiponectin levels are associated with serum hsCRP, IL-6 and IL-10 levels. These results suggest that adiponectin might be associated with the metabolic syndrome through regulation of pro-/anti-inflammatory cytokines.

Adiponectin↗

Therapeutic use of granulocyte-colony stimulating factor could conceal residual malignant cells in patients with AML1/ETO+ acute myelogenous leukemia.

We have experienced a number of cases of AML1/ETO+ acute myelogenous leukemia that showed remission based on bone marrow (BM) morphological criteria, but that revealed clonal abnormalities in most cells by fluorescence in situ hybridization (FISH). Interestingly, most of these cases had AML with AML1/ETO rearrangement. The malignant cells were differentiated and considered mature cells after granulocyte-colony stimulating factor (G-CSF) treatment. To clarify the possible mechanisms underlying this phenomenon, we investigated the expression levels of G-CSFR in AML cells with AML1/ETO rearrangement by flow cytometry and real-time polymerase chain reaction (PCR). The number of AML1/ETO+ cells expressing G-CSFR at baseline was significantly higher than that of AML1/ETO- AML cells (2673 vs 522). In addition, the G-CSFR gene was more highly expressed in AML1/ETO+ cells than in AML1/ETO- cells by real-time PCR. This study reveals that cases showing remission after treatment with G-CSF mostly had leukemia with AML1/ETO rearrangement. This finding might be explained by the higher expression of G-CSF receptor in AML1/ETO+ cells than in AML1/ETO- cells. We recommend that remission should be confirmed by FISH, because malignant clones can be differentiated and masked in morphological examination or chromosome test, especially for AML with AML1/ETO rearrangement.

Adolescent↗

Preparation and drug release activity of scaffolds containing collagen and poly(caprolactone).

A new biodegradable polymeric scaffold was prepared by using collagen and poly(caprolatctone) (PCL). These scaffolds were found to be soft, spongy, and transparent in nature and characterized by thermogravimetric analysis and FTIR spectrum. To these biodegradable polymeric scaffolds, antibiotic drugs namely amikacin and gentamycin were incorporated separately to study their release pattern from scaffolds. Amikacin and gentamycin release activity of the scaffolds containing a constant quantity of collagen but different quantities of PCL were studied at various time intervals viz. 1, 4, 24, and 48 h by measuring the optical density at 257 and 255 nm, respectively.

Animals↗

Cyclosporine-induced apoptosis in osteosarcoma cells.

INTRODUCTION: Posttransplant bone disease is one of the complications of cyclosporine (CsA), which is widely used as an immunosuppressive agent in the field of kidney transplantation. Cyclosporine treatment causes osteopenia as a result of altered bone turnover, but the pathogenic mechanisms of this process remain unclear. This study examined the ability of CsA to induce apoptosis in a rat osteoblast cell line. RESULTS: We induced apoptosis in rat osteoblastic ROS 17/2.8 cells by exposure to CsA. MTT assay showed that CsA exhibited significant cytotoxic effects on ROS 17/2.8 cells in a dose-dependent manner. Western blot analysis showed enhanced processing of caspase-8, Bax, and p53 after CsA treatment. Expression of cleaved poly (ADP-ribose) polymerase (PARP) was elevated by CsA treatment. Pro-caspase-3 and Bcl-2 proteins were decreased by CsA. CONCLUSIONS: These results suggested that CsA induced apoptosis of osteoblasts.

Animals↗

Evaluation of subchronic inhalation toxicity of dimethyl disulfide in rats.

This study was carried out to investigate the potential subchronic inhalation toxicity of dimethyl disulfide (DMDS) via whole-body exposure in F344 rats. Groups of 10 rats of each sex were exposed to DMDS vapor by whole-body exposure at concentrations of 0, 5, 25, or 125 ppm for 6 h/day, 5 days/wk for 13 wk. All the rats were sacrificed at the end of treatment period. During the test period, clinical signs, mortality, body weights, food consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, gross findings, organ weights, and histopathology were examined. At 25 ppm, a decrease in the body weight gain, food intake, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and blood urea nitrogen (BUN) was observed in the males, but not in the females. However, at 125 ppm, a decrease in the body weight gain, food intake, and thymus weight and an increase in the weights of adrenal glands were observed in both genders. Serum biochemical investigations revealed a decrease in the AST, ALT, BUN, creatine phosphokinase (CPK), and triglyceride levels and an increase in the glucose level. In contrast, no treatment-related effects were observed in the 5 ppm group. The toxic potency of DMDS was slightly higher in males than that in females. In these experimental conditions, the target organ was not determined in rats. The no-observed-adverse-effect concentration (NOAEC) was found to be 5 ppm, 6 h/day for male rats and 25 ppm, 6 h/day for female rats.

Alanine Transaminase↗

Identification of Salmonella enterica serovar Typhimurium using specific PCR primers obtained by comparative genomics in Salmonella serovars.

Salmonella enterica serovar Typhimurium is a major foodborne pathogen throughout the world. Until now, the specific target genes for the detection and identification of serovar Typhimurium have not been developed. To determine the specific probes for serovar Typhimurium, the genes of serovar Typhimurium LT2 that were expected to be unique were selected with the BLAST (Basic Local Alignment Search Tool) program within GenBank. The selected genes were compared with 11 genomic sequences of various Salmonella serovars by BLAST. Of these selected genes, 10 were expected to be specific to serovar Typhimurium and were not related to virulence factor genes of Salmonella pathogenicity island or to genes of the O and H antigens of Salmonella. Primers for the 10 selected genes were constructed, and PCRs were evaluated with various genomic DNAs of Salmonella and non-Salmonella strains for the specific identification of Salmonella serovar Typhimurium. Among all the primer sets for the 10 genes, STM4497 showed the highest degree of specificity to serovar Typhimurium. In this study, a specific primer set for Salmonella serovar Typhimurium was developed on the basis of the comparison of genomic sequences between Salmonella serovars and was validated with PCR. This method of comparative genomics to select target genes or sequences can be applied to the specific detection of microorganisms.

Base Sequence↗

Effect of PPAR-alpha and -gamma agonist on the expression of visfatin, adiponectin, and TNF-alpha in visceral fat of OLETF rats.

A variety of adipocytokines and peptides secreted from adipocytes have been considered to play a crucial role in obesity, insulin resistance, and type 2 diabetes. Recently, visfatin, a new adipocytokine, known as a pre-B cell colony-enhancing factor, has been isolated from visceral fat deposits. It has been shown to activate insulin receptors in a manner different from insulin. To understand the role of adipocytokines in improving insulin sensitivity via activation of the nuclear receptor peroxisome proliferator-activated receptor-alpha (PPAR-alpha) and -gamma (PPAR-gamma), we examined the expression of visfatin, adiponectin, and TNF-alpha in visceral fat depots of Otsuka Long-Evans Tokushima fatty (OLETF) rats from early to advanced diabetic stage (from 28 to 40 weeks of age). Serum glucose and insulin concentrations significantly (P<0.05) decreased in rosiglitazone or fenofibrate-treated OLETF rats compared to untreated OLETF rats. Rosiglitazone significantly increased serum adiponectin concentration from 20 to 40 weeks of age (P<0.05), whereas fenofibrate reduced TNF-alpha concentration. The expression of visfatin and adiponectin mRNA in visceral fat deposits was elevated by rosiglitazone or fenofibrate treatments when compared to untreated OLETF rats (P<0.05), whereas, TNF-alpha mRNA was down-regulated by these drugs (P<0.05). These results suggest that rosiglitazone and fenofibrate may prevent type 2 diabetes by regulating adipocytokines including visfatin, adiponectin, and TNF-alpha.

Adiponectin↗

Effects of green tea consumption on inflammation, insulin resistance and pulse wave velocity in type 2 diabetes patients.

In this study, we examined the effects of green tea on inflammation and arterial stiffness in type 2 diabetes patients. As results, inflammatory markers, such as hsCRP and IL-6, were unchanged after green tea consumption, and neither were blood glucose, lipid profiles, insulin resistance, or serum adiponectin levels. Furthermore, tea consumption did not improve baPWV. These results suggest that the above-described mechanisms are unlikely to explain the cardiovascular risk reduction by tea consumption observed in epidemiological studies.

Beverages↗

Spectral studies of SnO2 nanofibres prepared by electrospinning method.

Tin oxide nanofibres with 100-150 nm diameter has been prepared, for the first time by calcination of poly(vinyl acetate) (PVAc)/SnO2 composite fibres prepared by electrospinning method as precursor. Scanning electron microscopic images revealed cylindrical morphology of the fibres after calcination at 600 degrees C. Both, X-ray diffraction (XRD) and Raman spectral data confirmed the presence of phase pure tetragonal rutile tin oxide after calcination process. Room temperature photoluminescence (PL) spectra of tin oxide nanofibres under excitation at 325 nm wavelength show a strong green emission at 525 nm with a band gap of 2.41 eV. FT-IR spectra confirmed the formation of pure tin oxide after calcination at 600 degrees C and complete removal of PVAc during calcination. UV-vis spectrum of the fibres showed absorption at 315 nm due to the direct electron transfer in tin oxide.

Crystallization↗

Association among serum ferritin, alanine aminotransferase levels, and metabolic syndrome in Korean postmenopausal women.

We examined the relationships among serum ferritin, alanine aminotransferase (ALT) levels, and cardiovascular risk factors of metabolic syndrome in Korean postmenopausal women. We conducted a cross-sectional study of 959 postmenopausal women without an apparent cause of liver disease. Metabolic syndrome was defined as the presence of at least 3 of the following: elevated blood pressure, low high-density lipoprotein cholesterol, elevated serum triglycerides, elevated plasma glucose, and abdominal obesity. Serum ferritin and ALT levels were found to be correlated (r=0.374, P<.001) and to be associated with the components of metabolic syndrome. Subjects with metabolic syndrome showed significantly higher serum ferritin (74.7+/- 2.0 vs 59.6+/- 2.0 ng/mL, P<.001) and ALT levels (21.3+/-1.6 vs 18.7+/-1.5 IU/L, P<.001). Moreover, the greater the number of metabolic syndrome components present, the higher were the serum ferritin and ALT levels (P<.001). Multiple regression analysis showed that serum ALT levels are significantly associated with serum ferritin levels, waist circumference, fasting blood glucose, age, and white blood cell count (adjusted R(2)=0.147). Elevated iron stores were positively associated with serum ALT levels and metabolic syndrome in Korean postmenopausal women.

Aged↗

Intussusception after gastric surgery.

Intussusception following gastric surgery is a rare postoperative complication. It may develop in clinical situations following gastroenterostomy, Billroth II gastric surgery with or without Braun anastomosis, or Roux-en-Y gastrojejunostomy. The patients may present with either an acute surgical emergency or with a chronic, relapsing form. The mortality may be up to 50 % in these cases if not treated appropriately, but little is known about the mechanism underlying the condition. Early diagnosis with a high index of suspicion and prompt treatment of the acute form are therefore important. Surgical reduction with laparotomy is mandatory, although definitive corrective and preventative measures have not yet been established.

Adult↗

Serum osteoprotegerin levels are associated with inflammation and pulse wave velocity.

OBJECTIVE: We examined the association between serum osteoprotegerin (OPG) levels, systemic inflammation and arterial stiffness in normal and diabetic patients. PATIENTS AND MEASUREMENTS: The study subjects comprised 49 newly diagnosed diabetic patients and 72 age- and sex-matched normal glucose controls. Anthropometric parameters, blood pressure, fasting blood glucose (FBG), lipid profiles, serum OPG, high-sensitive C-reactive protein (hsCRP), interleukin-6 (IL-6) and brachial-ankle pulse wave velocity (baPWV) were measured. RESULTS: Serum OPG levels (6.1 +/- 1.4 vs. 5.4 +/- 1.3 pmol/l, P = 0.011) and baPWV (1562 +/- 354 vs. 1399 +/- 257 cm/s, P = 0.004) were significantly higher in the diabetic group than in the normal glucose group. Serum OPG levels in normal and diabetic patients correlated significantly with systolic blood pressure (r = 0.20, P = 0.035), FBG (r = 0.30, P = 0.002), right baPWV (r = 0.22, P = 0.021), left baPWV (r = 0.26, P = 0.006), homeostasis model assessment insulin resistance (HOMA-IR) (r = 0.19, P = 0.045), IL-6 (r = 0.32, P = 0.001) and hsCRP (r = 0.21, P = 0.027) after adjusting for age and sex. Multiple regression analysis showed that serum OPG level was significantly associated with age, FBG, IL-6, systolic blood pressure, triglyceride and hsCRP (R(2) = 0.299). CONCLUSIONS: In summary, serum OPG and baPWV levels are elevated in diabetic patients and serum OPG levels are significantly associated with inflammation and arterial stiffness.

Biomarkers↗