Search PubMed⌕ Search

Biomedical subjects

Y H Kim

Publications and source records attributed to Y H Kim.

At least 37 records · Page 2Linked to original sources
PubMed2005

Docetaxel (Taxotere), cisplatin, UFT, and leucovorin combination chemotherapy in advanced gastric cancer.

We conducted this study to ascertain the efficacy and toxicity of docetaxel and cisplatin combined with oral UFT and leucovorin as a first-line treatment for patients with advanced gastric cancer. In all, 52 patients received courses of docetaxel 60 mg m(-2) intravenously (i.v.) for 1 h and then cisplatin 75 mg m(-2) i.v. for 2 h on day 1. Oral UFT at 400-600 mg day(-1), as determined by body surface area, and leucovorin at 75 mg day(-1) were administered for 21 consecutive days from day 1, and this was followed by a 7-day drug-free interval. A total of 225 courses were administered, and the median number of courses per patient was four. Four complete responses (7.7%) and 22 partial responses (42.3%) were achieved, giving an overall response rate of 50% (95% Confidence Interval: 36.4-63.6%). The major toxicity was neutropenia, which reached grade 3/4 in 36 patients (69.3%). Grade 3/4 nausea and vomiting was observed in 12 patients (23.1%). Median time to progression was 22 weeks (4 to 156+ weeks), median survival duration was 48 weeks (4 to 156+ weeks), and median response duration was 24 weeks (6-152 weeks). We conclude that docetaxel, cisplatin, oral UFT, and leucovorin combination chemotherapy is effective and tolerable for the treatment of advanced gastric cancer.

Adenocarcinoma↗
PubMed2005

ER stress-induced caspase-12 activation is inhibited by PKC in neuronal cells.

Caspase-12 is activated when the cells are exposed to excess levels of various stimuli, which cause endoplasmic reticulum (ER) stress. Protein kinase C (PKC) plays an important role in many signaling pathways in cells, and the activation of PKC has multiple actions in the signaling function of the ER. This study examined whether or not phorbol 12, 13-dibutyrate (PDBu)-induced PKC activation modulates caspase-12 cleavage and it's processing, using a wild type caspase-12 overexpressing neuronal cell line, known as Cas-12 cells. The thapsigargin treatment induced caspase-12 fragmentation in the Cas-12 cells. This was inhibited by PKC, which had previously been stimulated by PDBu. The PDBu treatment attenuated the ER stress-induced translocation of caspase-12 from the ER to the cytoplasm. The caspase-3 specific inhibitor blocked caspase-12 fragmentation, and purified caspase-12 was cleaved by the active caspase-3 in vitro, suggesting that caspase-12 might be a substrate for caspase-3. In addition, the PDBu treatment influenced the decrease of active caspase-3 fragment. These results suggest that an ER stress induces the activation of caspase-12 via caspase-3, and that PKC regulates both caspase-12 and caspase-3 activations in Cas-12 cells.

Animals↗
PubMed2005

Long-term graft outcome of living donor renal transplantation: single center experience.

UNLABELLED: The number of potential renal transplant recipients far exceeds the number of cadaveric donors. For this reason, living-related donors (LRD) and living-unrelated donors (LURD) have been used to decrease the cadaveric donor shortage. We analyzed 571 living donor transplants for 25 years in our center. MATERIALS AND METHODS: From 1978 to 2003, 571 patients underwent LRD (n = 253), or LURD (n = 318) kidney transplantation. The patients were divided into precyclosporine era (from 1978 to 1987, n = 44; era I), cyclosporine era (from 1988 to 1997, n = 367, era II), and cyclosporine plus mycophenolate-mofetil era (from 1998 to 2003, n = 160, era III). We compared the graft survival rate of the recipients according to the immunosuppressants, analyzing the variables of donor and recipient age, sex, HLA matching, and acute rejection rate. We also compared long-term survival rates between LRD and LURD. RESULTS: The 1- and 10-year graft survival rates of all patients were 93.4% and 77.4%, respectively. The 1- and 10- year graft survival rates were 75.0% and 36.3% in era I; and 94.8 % and 80.2% in era II. The 1- and 5-year graft survival rates were 96.6% and 93.3% in era III (P < .001). The occurrence rate of an acute rejection episode was 11.4% (era I), 21.8% (era II), and 14.4% (era III) (P = .056). The 1- and 5-year graft survival rates were 92.3% and 81.7% among LRD transplants, and 94.2% and 86.9% among LURD transplants, respectively (P = .122). DISCUSSION: The graft survival rates of living-donor transplants are improving due to advances in patient care and new immunosuppressive agents.

Cyclosporine↗
PubMed2005

Analysis on donor and isolation-related factors of successful isolation of human islet of Langerhans from human cadaveric donors.

We analyzed the preexisting donor factors and isolation variables that affected isolation of human islets of Langerhans. Sixty-nine pancreata from cadaveric donors were analyzed for donor factors of age, gender, body mass index, cause of death as well as graft factors of cold ischemia time, pancreas status, distensibility during intraductal collagenase distension and time of collagenase expansion and digestion. Islet isolations that recovered >100,000 IEQ (n = 53) were compared to those generating less than 100,000 IEQ (n = 16) to analyze the factors affecting islet yield during donor harvest and isolation procedures. The mean islet recovery was 216.0 x 10(3) (IEQ) or 2840 (IEQ) per gram of pancreas. Mean purity was 54%. The success rate of islet isolation was 76%. Mean age was 31 years, and mean cold ischemia time was 6.9 hours. In univariate analysis, the status of the pancreas was the only significant factor for successful isolation, and gender, time of collagenase expansion and digestion were marginal factors. In stepwise multivariate logistic regression analysis of donor and isolation-related factors, donor gender, pancreas status and digestion time were significant factors. During the same period we performed three cases of clinical islet allotransplantation and one autotransplantation. This study confirmed that the same donor factors and variables in the isolation process can affect the ability to obtain successful human islet isolation. Enough experience and pertinent review of donor and isolation factors can make islet isolation consistent, supporting clinical islet transplantation without unnecessary cost.

Adult↗
PubMed2005

Comparative study on biologic and immunologic characteristics of the pancreas islet cell between 24 degrees C and 37 degrees C culture in the rat.

The aim of this study was to investigate the effect of culture at 24 degrees C on cell viability, cellular function, immunogenicity, and cytokine profiles of rat pancreatic islets. Pancreatic islets were isolated from Lewis rats and cultured at either 24 degrees C or 37 degrees C for 14 days. Islet recovery was counted as islet equivalents; islet viability was examined with fluorescent vital staining. Islet function was measured with a glucose stimulation test. Annexin V, and MHC class I and II expression were measured using flow cytometric assay for apoptosis and immunogenicity, respectively. Lymphocyte cell proliferation was examined with WST-1 proliferation assay. Cytokine profiles were analyzed with quantitative real time RT-PCR. All these parameters were measured on 1, 3, 5, 7 and 14 culture days after islet isolation. Islet recovery was higher in islets cultured at 24 degrees C than 37 degrees C without a change in viability. Insulin secretion after glucose stimulation was more effective in 24 degrees C culture conditions. Decreased apoptotic cell death was demonstrated in 24 degrees C cultured islets. Both MHC class I and II expression on islets and lymphocyte proliferation upon coculture with islets were less prominent in 24 degrees C cultured islets. TNF-alpha expression was lower in islets cultured at 24 degrees C than in islets cultured at 37 degrees C. Both IL-1beta and IL-10 cytokine expressions were similar under both culture conditions. This study demonstrated that cell recovery and function are increased in islets cultured at 24 degrees C than those at 37 degrees C with decreased antigenicity and proinflammatory cytokine expression.

Animals↗
PubMed2005

Characterization of humic substances isolated from Han River water and change in the structural and chemical characteristics by ozonation.

This study investigated the characteristics of extracted humic substances, which are ubiquitous in river waters and affect the treatment of water. Humic substances were extracted from the Han River water and analyzed using the samples obtained before/after ozonation with various analytical items. Ozonation was conducted in a batch-type reactor, and ozone was dosed from 0 to 2.0 mg O3 mg(-1) humic substances. The humic fraction was 56.0% of total organic carbon in the Han River and the ratio of fulvic to humic acids was approximately 3.46, including aromatic ring structures and/or various functional groups. Humic substances could not completely be oxidized to CO2, H2O, etc., but partly oxidized to low molecular weight matter, thus low removal efficiencies in terms of dissolved organic carbon (31% at 1.0 mg O3 mg(-1) humic substances) were observed. For UV absorbance at the wavelength 254 nm, ozone dose at 1.0 mg O3 mg(-1) humic substances showed more than 80% removal efficiencies. The molar ratios of H/C and O/C of the humic substances structure relatively increased by ozonation, indicating the degradation of aromatic groups in the humic substances molecule. The Fourier transform infrared spectra and proton nuclear magnetic resonance spectra of humic substances showed the increase in carboxylic acids and the decrease in aromatic protons through ozonation, respectively. As specific reaction sites in the humic substances including aromatic ring structures were reduced through ozone oxidation, contents of carboxylic acids, ketones and quinones in the humic substances molecule increased.

Bioreactors↗
PubMed2005

Optimization of technical conditions for the transformation of Lactobacillus acidophilus strains by electroporation.

AIMS: To optimize the conditions for electroporating foreign plasmid DNA into Lactobacillus acidophilus ATCC 43121. METHODS AND RESULTS: The conditions of electroporation were optimized to improve the transformation efficiency. Plasmid pNZ123 containing multicloning site and chloramphenicol resistance was employed to construct a cloning vector. The optimum electroporation conditions for the maximum transformation efficiency were a pulse strength of 12.5 kV cm(-1), a pulse number of 10, a pulse interval of 500 ms, and pNZ123 plasmid DNA concentration of 25 ng microl(-1). Under the optimum conditions the transformation efficiency of L. acidophilus ATCC 43121 was 1.84 +/- 0.13 x 10(4) (+/- standard error of measurements) CFU per mug of plasmid DNA. Other strains of L. acidophilus showed transformation efficiencies ranging from 1.38 +/- 0.02 x 10(4) to 9.32 +/- 0.54 x 10(4) under these conditions. A green fluorescent protein (GFP) was successfully expressed and detected by fluorescence microscopy when the pKU::slpA-GFP, pNZ123 containing GFP gene, was transformed in L. acidophilus ATCC 43121 under the optimum conditions. CONCLUSIONS: The results suggest that electrical parameters, antibiotic concentration, and host specificity play important roles to determine transformation efficiency of lactobacilli. The optimum conditions for the transformation of L. acidophilus ATCC 43121 may be applied to improve transformation efficiency of other lactobacilli. SIGNIFICANCE AND IMPACT OF THE STUDY: The optimized conditions for electrotransformation may provide a mean to improve the introduction of foreign DNA into L. acidophilus to be used as a vehicle for a heterologous protein expression.

Anti-Bacterial Agents↗
PubMed2005

Protein C and/or S deficiency presenting as peripheral arterial insufficiency.

Although protein C and/or S deficiency has frequently been associated with venous thromboembolic events, instances of arterial thromboses have been reported. However, the exact incidence of protein C and/or S deficiency in patients with peripheral arterial insufficiency has not been established. Furthermore, given the lack of adequate studies to define the natural history and angiographic findings of these patients, the treatment has not been well delineated. Therefore, we conducted a prospective study to investigate the prevalence, characteristic angiographic findings and optimal treatments in patients with peripheral arterial insufficiency associated with protein C and/or S deficiency. Between September 2000 and August 2004, 133 patients who presented with peripheral arterial insufficiency underwent hypercoagulability tests before the initiation of any treatments. Of these, 11 patients (8.3%) with protein C and/or S deficiency were included in this study. There were nine males and two females. The ages ranged from 38 years to 72 years (mean 57 years). All patients showed characteristic angiographic findings: long segment thrombotic occlusion of a main peripheral artery without evidence of atherosclerosis or with mild atherosclerotic changes in the aorta and other major arterial trees. Surgical or endovascular procedures were performed in nine patients: bypass graft in four, thrombectomy in four and catheter-directed thrombolysis in one. Conservative treatment with full anticoagulation was performed in two patients. All patients received pre- and post-operative anticoagulation. Except for one amputated case, clinical and vascular laboratory improvements were achieved in 10 patients. Mean follow-up period was 21 months (range 4-45 months). However, one patient, in whom re-vascularization surgery was performed successfully, discontinued warfarin therapy himself at 10 months after surgery, graft occlusion and limb loss occurred at 30 months after surgery. This initial experience suggests that protein C and/or S deficiency may be an independent risk factor for peripheral arterial insufficiency. Patients who present with peripheral arterial insufficiency and protein C and/or S deficiency demonstrate characteristic angiographic findings. Once the diagnosis of protein C and/or S deficiency is made, patients should be treated with life-long anticoagulation.

Adult↗
PubMed2004

Oxidation of buried cysteines is slow and an insignificant factor in the structural destabilization of staphylococcal nuclease caused by H2O2 exposure.

The oxidation of buried cysteine or methionine residues can destroy the enzyme activity of a protein by disrupting structure. Engineering in such an oxidatively triggered switch for enzyme activity would only be useful if the effects of substitution are relatively minor, while the effects of the oxidized side chain upon structure are significant and the oxidation relatively easy. To assess the feasibility of this strategy for controlling enzyme activity, the effects of such substitutions and their oxidation were studied in a well characterized model protein, staphylococcal nuclease. Stability and enzyme activity of the oxidized proteins was assessed and compared to the stability and enzyme activity of the unoxidized proteins. Cysteines were found to be generally well tolerated in buried positions but these mutants were not more destabilized than wild-type when oxidized. This shows that buried cysteines are difficult enough to oxidize that this is not likely to be a useful protein engineering strategy or a commonly used regulatory modification. Similar effects were observed for methionine.

Binding Sites↗
PubMed2004

Real-time compound ultrasonography: pictorial review of technology and the preliminary experience in clinical application of the abdomen.

The purposes of this essay are to illustrate the technology overview and theoretical benefits of real-time compound ultrasonography (US) and to present our preliminary clinical experience in the evaluation of normal and diseased abdomens. The application of compounding principles to real-time US and its recent reintroduction into mainstream commercial systems have offered new opportunities for its clinical application to the routine examination of the abdomen. In our early preliminary experience, this technique effectively suppressed many of the US artifacts, better depicted the margin or boundary of the lesion, and increased contrast resolution or lesion conspicuity. Therefore, we believe that real-time compound US is a promising technique that may enhance the diagnostic confidence of the examination in the evaluation of normal and diseased abdomens.

Abdomen↗
PubMed2004

Cerebral microbleeds are regionally associated with intracerebral hemorrhage.

BACKGROUND: Cerebral microbleeds (CMB) may be indicative of a hemorrhage-prone microangiopathy. OBJECTIVE: To determine if increased numbers of these lesions are predictive of intracerebral hemorrhage (ICH), especially in terms of a distributional association. METHODS: The authors examined consecutively 227 patients with acute stroke. CMB were counted using T2*-weighted gradient echo MRI data, and old lacunes and leukoaraiosis were also evaluated. The associations between the vascular risk factors and ICH were analyzed. With use of multivariate logistic regression analysis, the locations of the CMB or the old lacunes, which were categorized as being in the corticosubcortical area, the deep gray matter area, or the infratentorial area, were examined with regard to their relationships to the locations of the ICH. RESULTS: The degrees of the CMB (r = 0.43, p < 0.01) and leukoaraiosis (r = 0.20, p < 0.01) were well correlated with the presence of ICH. Multivariate analysis revealed that the grades of the CMB were associated with the presence of ICH (p < 0.01, odds ratio [OR] = 2.67). CMB in the corticosubcortical area (p < 0.01, OR = 5.50) or deep gray matter (p < 0.01, OR = 2.55) were strongly associated with the presence of ICH in the same area, but no such association was observed in the case of CMB in the infratentorial area or in the case of old lacunes in any area. CONCLUSIONS: Cerebral microbleeds are strongly associated with the presence of intracerebral hemorrhage, and the distributional associations are also quite strong.

Acute Disease↗
PubMed2004

Colonoscopic manifestations of typhoid fever with lower gastrointestinal bleeding.

BACKGROUND: Intestinal bleeding in patients with typhoid fever usually occurs in the ileum. However, endoscopic findings in such patients are not well established. We examined the colonoscopic manifestations of intestinal lesions with bleeding in patients with typhoid fever. PATIENTS AND METHODS: The colonoscopic findings of seven patients who presented with haematochezia due to typhoid fever were reviewed retrospectively. Typhoid fever was diagnosed when the Salmonella typhi was isolated or when the Widal test showed strongly positive reactions. RESULTS: Clinical data and colonoscopic findings were reviewed in seven patients (four men and three women with an average age of 42 years). The most commonly involved area was the terminal ileum (100%), followed by the ileocecal valve (57%), the ascending colon (43%), and the transverse colon (29%). Left colon was intact in all cases. The most common colonoscopic finding was multiple variable-sized punched-out ulcers with slightly elevated margin, as found in five patients. In two patients, only several oedematous hyperaemic mucosal patches with haemorrhagic spots or shallow erosions were seen. Active bleeding was noticed only in one patient, who received endoscopic haemostasis twice. The remaining six patients were treated by conservative treatment including antibiotic therapy. There was no complication during or after the colonoscopic examination. CONCLUSIONS: Intestinal bleeding in typhoid fever usually occurs from the ulcers in the ileum or proximal colon, and the most common colonoscopic manifestations are multiple variable-sized punched-out ulcerations.

Adult↗
PubMed2004

Experimental islet isolation in porcine pancreas with new enzyme Liberase PI.

The aim of this study was to investigate the results of 20 consecutive porcine islet isolations using a new enzyme Liberase PI. Twenty pancreata were procured for islet isolation, which was performed using modified Ricordi's method with Liberase PI. Quantitation of islet viability staining, insulin stimulation assay, intracellular insulin content/DNA, and in vivo transplantability into diabetic nude mice were examined for quality control. The results were compared between a high-yield group (>2500 IEQ/g pancreas) and a low-yield group (<2500 IEQ/g pancreas). Sufficient amount of purified islets (3000 IEQ/g pancreas) were obtained using the new brand enzyme Liberase PI. These islets showed good quality in structure and functions, which were demonstrated by in vitro and in vivo standard assays. Isolation index (IEQ/number) of the low-yield group was lower than that of high-yield group (0.75 vs 0.86), which means more fragmentation of islets in the low-yield group. There were no differences in function between the two groups. In conclusion, we obtained sufficient numbers of viable, functional islets from porcine pancreas using a new brand enzyme Liberase PI and low-temperature isolation technique. However, overdigestion of islets during the isolation remains to be overcome. Advance in porcine islet isolation technique will in the future make the porcine islet xenotransplantation a reality for the cure of diabetes mellitus.

Animals↗
PubMed2004

Cytomegalovirus infection of the graft duodenum and urinary bladder after simultaneous pancreas-kidney transplantation.

Cytomegalovirus (CMV) is an important cause of morbidity after solid organ transplantation. We report a case of CMV infection involving the transplanted duodenum that developed after simultaneous pancreas-kidney transplantation. The patient, a 30-year-old woman with insulin-dependent diabetes undergoing hemodialysis due to chronic renal failure, received a simultaneous cadaveric pancreas-kidney transplantation. The exocrine secretion was diverted using bladder drainage. Immunosuppression was maintained by a combination of tacrolimus, mycophenolate mofetil, and steroids together with OKT3 induction. Both the donor and the recipient were serologically positive for CMV IgG CMV prophylaxis consisted of a short course of parenteral gancyclovir. The patient was discharged on postoperative day 39 with normal pancreas and kidney function. She presented 2 months after transplantation with hematuria. Cystoscopic pancreas allograft biopsy specimens showed evidence of tissue invasive CMV infection in the graft duodenum and bladder. The CMV antigenemia test was positive. At 4 months after transplantation, the patient underwent surgery with the diagnosis of acute abdomen. The surgical findings consisted of a diffuse acute purulent peritonitis due to perforation of the duodenal graft. We sutured the perforation with nonreabsorbable material. The CMV antigenemia test was negative. Eight days later, the patient developed massive hematuria. At surgery, the graft was removed. The patient was discharged from the hospital with normal renal function. Pathological study of the removed graft showed the duodenal segment to have multiple wide ulcers with CMV inclusions in epithelial cells.

Adult↗
PubMed2004

Transcription factor decoy for AP-1 reduces mesangial cell proliferation and extracellular matrix production in vitro and in vivo.

Diabetic nephropathy is characterized by an expansion of glomerular mesangium, caused by mesangial cell proliferation and excessive accumulation of extracellular matrix (ECM) proteins, which eventually leads to glomerulosclerosis and renal failure. Activator protein-1 (AP-1), a transcription factor, is implicated in the transcriptional regulation of a wide range of genes participating in cell proliferation and ECM production. This investigation was undertaken to test the hypothesis that AP-1 plays an important role in ECM gene expression, and to develop a molecular therapeutic strategy based on decoy oligodeoxynucleotides (ODN). In this report, we show that transfection with AP-1 decoy ODN strongly inhibits high glucose- and angiotensin II-induced cell proliferation and expression of ECM genes in cultured mesangial cells in vitro. Administration of AP-1 decoy ODN into streptozotocin-induced diabetic rat kidney in vivo using the hemagglutinating virus of Japan (HVJ)-liposome method virtually abolished TGF-beta1 and plasminogen activator inhibitor-1 expression. Our results collectively indicate that AP-1 activation is crucial for mesangial cell proliferation and ECM production in response to high glucose and angiotensin II. Moreover, use of stable AP-1 decoy ODN combined with the highly effective HVJ-liposome method provides a novel potential molecular therapeutic strategy for the prevention of diabetic nephropathy.

Angiotensin II↗
PubMed2004

Idiopathic spontaneous spinal subarachnoid hemorrhage.

INTRODUCTION: Spontaneous spinal subarachnoid hemorrhage (SAH) occurs in less than 1% of all cases of SAH, and idiopathic spontaneous spinal SAH is even more rare. METHODS: A 48-year-old man presented with a sudden onset of low back pain without any neurological deficit. There was no history of either trauma or the use of anticoagulants. Magnetic resonance (MR) imaging of the lumbar spine revealed an intradural linear mass from T12 to L3, ventral to the conus medullais and cauda equina. The mass was of iso-signal intensity in T2-weighted images, of high signal intensity in T1-weighted images, and was not enhanced following injection of gadolium. Lumbar tapping revealed bloody cerebrospinal fluid, confirming SAH. At 1 month after the onset of symptom, his pain subsided spontaneously and no vascular abnormality was found by spinal angiography. Follow-up MR imaging confirmed the complete resolution of the SAH. CONCLUSION: We report a case of idiopathic spontaneous spinal SAH at the lumbar level in a 48-year-old man.

Humans↗
PubMed2004

Prognostic significance of the expression of Smad4 and Smad7 in human gastric carcinomas.

BACKGROUND: Transforming growth factor-beta (TGF-beta) modulates the growth and function of many cells, including those with malignant transformation. Smad proteins have been identified as major components in the intracellular signaling of TGF-beta family members. PATIENTS AND METHODS: To clarify the correlations between clinicopathologic profiles and the patient's survival, the expression of common mediator Smad (Smad4) and inhibitory Smad (Smad7) were evaluated immunohistochemically in 304 consecutive gastric carcinomas using the tissue array method. RESULTS: Positive Smad4 expression was observed in 266 (87.5%) tumors and positive Smad7 expression in 98 (32.2%) tumors. The prognosis of patients with a Smad4-positive tumor was significantly better than that of the patients with a negative tumor. The survival rate was significantly higher in patients with negative Smad7 expression than those with positive Smad7 expression. In subgroup analysis according to TNM (tumour-node-metastasis) stage, both Smad4 and Smad7 showed most significant prognostic differences in stage I gastric cancer patients. Multivariate analysis indicated that tumor size, depth of invasion, lymph node metastasis and Smad7 expression were independent prognostic factors. CONCLUSION: Enhanced expression of the TGF-beta signaling inhibitor Smad7 may present one of the novel mechanisms of TGF-beta resistance in human gastric carcinomas.

Adult↗