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Biomedical subjects

S Kim

Publications and source records attributed to S Kim.

At least 307 records · Page 17Linked to original sources

Reversible left ventricular systolic dysfunction--reversibility of coronary microvascular abnormality.

Reversible left ventricular wall motion abnormalities mimicking myocardial infarction have been reported in patients with a noncardiac illness. Their coronary angiograms do not demonstrate organic stenosis or epicardial coronary vasospasm. In this article, two cases of reversible left ventricular contraction abnormality are presented. Electrocardiography showed deep inverted T waves in precordial leads, and the echocardiography revealed diffuse akinesis of the apical region in the acute phase. Coronary angiography showed no significant stenosis or occlusion in either patient. Thallium scintigraphy showed no defect, while the metaiodobenzylguanidine scintigraphy demonstrated significant defects in the apex. The relative coronary flow reserve ratio, measured with an intracoronary Doppler flow wire, was significantly reduced in both patients. Myocardial contrast echocardiography revealed a reversible perfusion defect in the apex in the acute phase in case 2. Transiently impaired coronary microcirculation was thought to be involved in the pathogenesis of the reversible left ventricular dysfunction observed in these patients.

Aged↗

Preoperative detection of hepatocellular carcinoma: ferumoxides-enhanced mr imaging versus combined helical CT during arterial portography and CT hepatic arteriography.

OBJECTIVE: The purpose of this study was to compare ferumoxides-enhanced MR imaging with combined helical CT during arterial portography and CT hepatic arteriography for preoperative detection of hepatocellular carcinomas. SUBJECTS AND METHODS: Twenty patients with 30 hepatocellular carcinomas underwent ferumoxides-enhanced MR imaging and combined helical CT during arterial portography and CT hepatic arteriography. The diagnosis was established by pathologic examination after surgical resection in 18 patients and by biopsy in two. The MR protocol included fast spin-echo with two echo times, T2(*)-weighted fast multiplanar gradient-recalled acquisition in the steady state, proton density-weighted fast multiplanar spoiled gradient-recalled echo, and T1-weighted fast multiplanar spoiled gradient-recalled echo images. The MR images of all sequences and the paired CT during arterial portography and CT hepatic arteriography images were independently evaluated by three radiologists on a segment-by-segment basis. Diagnostic accuracy was assessed with receiver operating characteristic analysis. RESULTS: The accuracies (A(z) values) of ferumoxides-enhanced MR imaging and combined CT during arterial portography and CT hepatic arteriography for all observers were 0.964 and 0.948, respectively. The mean sensitivities of MR imaging and CT were 93% and 91%, respectively. The differences were not statistically significant. The mean specificity of MR imaging (99%) was significantly higher than that of combined CT during arterial portography and CT hepatic arteriography (94%). CONCLUSION: Ferumoxides-enhanced MR imaging can be used successfully in place of combined CT during arterial portography and CT hepatic arteriography for the preoperative evaluation of patients with hepatocellular carcinomas.

Adult↗

Quantification of ground-glass opacity on high-resolution CT of small peripheral adenocarcinoma of the lung: pathologic and prognostic implications.

OBJECTIVE: The purpose of our study was to correlate the high-resolution CT findings of small peripheral adenocarcinoma of the lung with underlying histopathology and to evaluate the prognostic implications of the CT findings. MATERIALS AND METHODS: The high-resolution CT findings of small peripheral adenocarcinoma of the lung in 224 patients were analyzed by two independent observers for location, size, marginal characteristics, and extent of ground-glass opacity and necrosis. The pathologic specimens were reviewed by an experienced lung pathologist. RESULTS: One hundred and thirty-two patients had bronchioloalveolar carcinoma and 92 had adenocarcinoma. The extent of ground-glass opacity was greater in bronchioloalveolar carcinomas (mean +/- SD, 29% +/- 31.6%) than in other adenocarcinomas (8% +/- 13.3%) (p < 0.001). The extent of ground-glass opacity was significantly greater in patients without recurrence (p = 0.020) and those without nodal (p = 0.017) or distant (p = 0.007) metastases than in patients with nodal or distant metastases or in whom the carcinoma had recurred. CONCLUSION: The extent of ground-glass opacity in a nodule is greater in bronchioloalveolar carcinomas than in other adenocarcinomas. Greater extent of ground-glass opacity also correlates with improved prognosis.

Adenocarcinoma↗

Phosphorylation of p38 mitogen-activated protein kinase downstream of bax-caspase-3 pathway leads to cell death induced by high D-glucose in human endothelial cells.

Because high D-glucose significantly stimulates endothelial cell death, we examined the molecular mechanisms of high D-glucose-induced endothelial apoptosis. Treatment of human aortic endothelial cells with high D-glucose (25 mmol/l), but not mannitol and L-glucose, resulted in a significant decrease in cell number and a significant increase in apoptotic cells as compared with a physiological concentration (5 mmol/l). Interestingly, high D-glucose treatment significantly increased bax protein, accompanied by translocation of bax protein from cytosol to mitochondria-enriched heavy membrane fraction. In contrast, the expression and distribution of bcl-2 protein were not altered by high D-glucose. In addition, the activity of caspase-3 proteases was increased after exposure to high glucose, whereas caspase inhibitors prevented endothelial cell death induced by high D-glucose. On the other hand, p38 mitogen-activated protein kinase (MAPK) was markedly phosphorylated and showed sustained phosphorylation after stimulation. A specific inhibitor of p38 MAPK, SB 203580, and the overexpression of kinase-inactive p38 MAPK significantly attenuated cell death induced by high D-glucose in human aortic endothelial cells, whereas at 6 h after high D-glucose treatment, SB 203580 and overexpression of kinase-inactive p38 MAPK did not attenuate caspase-3 activation induced by high D-glucose. Importantly, caspase inhibitors significantly attenuated the sustained phosphorylation of p38 MAPK induced by high D-glucose. Thus, we finally focused the MAPK kinase (MEK) kinase 1 (MEKK1) to further examine the cross-talk between p38 MAPK and the bax-caspase proteases pathway. High D-glucose treatment induced MEKK1 cleavage, whereas caspase inhibitors significantly attenuated the cleavage. Importantly, kinase-inactive MEKK1 also blocked the phosphorylation of p38 MAPK induced by high D-glucose. Here, we demonstrated that high D-glucose induced apoptosis in human endothelial cells through activation of the bax-caspase proteases pathway and through phosphorylation of p38 MAPK mediated by MEKK1. Phosphorylation of p38 MAPK downstream of the bax-caspase pathway may play a pivotal role in endothelial apoptosis mediated by high D-glucose.

Animals↗

Enhanced neutrophil functions by recombinant human granulocyte colony-stimulating factor in diabetic patients with foot infections in vitro.

This study was performed to evaluate the effect of granulocyte-colony stimulating factor on neutrophil functions in diabetic patients with active foot infections in vitro. Twelve diabetic patients with foot infections and 12 normal volunteers were enrolled. Neutrophils from peripheral blood were incubated with granulocyte colony-stimulating factor (G-CSF, 50 ng/mL) for 20 min. Superoxide production of neutrophils was measured by the reduction of ferricytochrome C. Neutrophil phagocytosis was assayed using Staphylococcus aureus and the weighted phagocytic index was calculated. Superoxide production of neutrophils in diabetic patients with foot infections was 7.7 (unit: nmol/2 x 10(5) cells/60 min), which was significantly lower than that in controls (12.0) (p<0.05). G-CSF increased neutrophil superoxide production to 12.1 in diabetic patients with foot infections and to 19.8 in controls (p<0.05 for each). Weighted phagocytic index in diabetic patients with foot infections was 0.77, which was not significantly different from that of the controls (0.69). Weighted phagocytic index was increased significantly by G-CSF to 0.88 in diabetic patients with foot infections and to 0.79 in controls (p<0.05 for each). In conclusion, G-CSF significantly enhanced neutrophil functions in diabetic patients with foot infections in vitro.

Adult↗

Does albumin preinfusion potentiate diuretic action of furosemide in patients with nephrotic syndrome?

The aim of this cross-over study was to investigate whether albumin infusion before furosemide administration could potentiate the diuretic action of furosemide. Seven patients with nephrotic syndrome were given the following infusions in random order on two separate days: 1) a sham solution followed by 160 mg of furosemide, 2) 100 ml of 20% human albumin followed by 160 mg of furosemide. Urine and serum furosemide concentrations were measured by high-performance liquid chromatography. The increment of urine volume was greater in albumin preinfusion than in furosemide alone. However, the increments of sodium and chloride excretions between furosemide alone and albumin preinfusion were not different. No significant differences in the pharmacokinetic parameters between the two treatments were observed: area under the concentration-time curve (AUC: 12.7+/-2.2 vs 15.1+/-4.4 g/ml hr), total plasma clearance (253+/-41 vs 256+/-54 ml/min), volume of distribution (341+/-34 vs 494+/-153 ml/kg), elimination half life (4.0+/-1.1 vs 4.6+/-0.8 hr), and urine furosemide excretion of the administered amount (16.5+/-7.3 vs 7.5+/-1.6%). In conclusion, these data show that albumin preinfusion potentiated diuresis, but not natriuresis, of furosemide without any change in the pharmacokinetics of the agent in patients with nephrotic syndrome.

Adolescent↗

Pseudomonas aeruginosa as a potential cause of antibiotic-associated diarrhea.

Although Pseudomonas aeruginosa is not generally considered as a cause of antibiotic-associated diarrhea, several cases of diarrhea caused by P. aeruginosa have been reported. We experienced seven cases of nosocomial diarrhea presumably caused by P. aeruginosa, which was the predominant organism isolated from stool cultures. Clostridium difficile toxin was also positive in one patient. No other potential or recognized enteropathogens were identified from stools. All patients had underlying diseases and had been receiving antibiotics before the diarrheal onset. All of the seven P. aeruginosa isolates were resistant to previously given antibiotics. Diarrhea stopped three days after withdrawal of probable offending antibiotics without specific treatment in two patients. The other five patients having continuous diarrhea despite withdrawal of probable offending antibiotics, were successfully treated with antipseudomonal agents. The median duration of diarrhea after the initiation of treatment was 6.3 days. These data suggest that P. aeruginosa can be a potential cause of antibiotic-associated diarrhea. Further investigations are warranted to evaluate the possible etiologic role of P. aeruginosa in antibiotic-associated diarrhea.

Adult↗

Detection of parenchymal abnormalities in acute pyelonephritis by pulse inversion harmonic imaging with or without microbubble ultrasonographic contrast agent: correlation with computed tomography.

The purpose of this study was to evaluate the ability of pulse inversion harmonic imaging with or without microbubble ultrasonographic contrast agent in depicting renal parenchymal changes in acute pyelonephritis. The study population included 30 patients with acute pyelonephritis and 10 healthy volunteers. Pulse inversion harmonic imaging with or without contrast agent was compared with conventional ultrasonography and tissue harmonic imaging in terms of detection and conspicuity of renal abnormalities. The detection and conspicuity of renal parenchymal abnormalities in acute pyelonephritis on tissue harmonic imaging, pulse inversion harmonic imaging, and contrast-enhanced pulse inversion harmonic imaging were significantly better than those on conventional ultrasonography. In 2 of 10 healthy volunteers all 4 techniques yielded false-positive diagnoses of parenchymal abnormalities. In conclusion, tissue harmonic imaging and pulse inversion harmonic imaging are sensitive techniques for depicting renal parenchymal lesions in acute pyelonephritis. Despite relatively lower specificities and negative predictive values, these techniques are thought to be useful for the depiction of subtle parenchymal changes in acute pyelonephritis.

Acute Disease↗

Antiangiogenic effect of KR31372 in rat sponge implant model.

A rat sponge implant model was used to examine the antiangiogenic effect of KR31372. Topical administration of angiotensin II (AII, 100 ng, daily) into the sponges enhanced the basal sponge-induced neovascularization, leading to higher clearance of (99m)Tc, increased retention of dye in the vessels, and increased numbers of blood vessels. These AII-induced changes were significantly suppressed by oral administration of KR31372 (1 mg/kg for 7 days). Angiogenic effect of recombinant human VEGF(165) (200 ng) was modestly higher than that of AII, which was also significantly inhibited by KR31372. KR31372-mediated suppression of (99m)Tc clearance was reversed by glibenclamide. Levcromakalim showed a modestly suppressive effect on the AII-induced angiogenesis. In conclusion, KR31372 exerted a strong inhibitory effect on the sponge-induced neovascularization, in part, through mediation of glibenclamide-sensitive K(+) channel activation. It is suggested that it may have therapeutic potential in the treatment of angiogenic disorders.

Angiogenesis Inhibitors↗

Differential effects of adenovirus-p16 on bladder cancer cell lines can be overcome by the addition of butyrate.

High frequency of p16 alteration and high local recurrence rate of bladder cancer make this cancer an ideal target for p16 gene therapy. However, a low transduction rate of p16 via adenoviral vector causes an inconsistent result. In this study, we have tested adenovirus-p16 in several bladder cancer cell lines and investigated a way of improving the low transduction rate. Adenovirus-p16 showed a strong antitumor effect on bladder cancer cell lines (253J and T24) with strong Coxackie-adenoviral receptor (CAR) expression but little antitumor effect on bladder cancer cell lines (J82 and HT1376) with little CAR expression. In this study, we suggest a simple way of overcoming the differential effects of the adenovirus. The addition of butyrate to media was found to increase the transduction rate of adenovirus remarkably and increase the antitumor effect of adenovirus-p16 in bladder cancer cell lines with little CAR expression. Butyrate effects were related with increased CAR expression on the cell surface as well as increased transgene expression from adenoviral vector. From these observations, application of adenovirus-p16 gene therapy with butyrate can overcome the obstacle of low gene transfer and enhance the antitumor effect of adenovirus-p16 in bladder cancer.

Adenoviridae↗

Phylogenetic relationships in family Magnoliaceae inferred from ndhF sequences.

The ndhF sequences of 99 taxa, representing all sections in extant Magnoliaceae, were analyzed to address phylogenetic questions in the family. Magnolia macrophylla and M. dealbata, North American species of Magnolia section Rytidospermum, are placed at the base in the subfamily Magnolioideae although its supporting value is low. In the remaining taxa, several distinctive lineages are recognized: (1) Magnolia, the biggest genus in the family, is not monophyletic; (2) Michelia, including section Maingola of Magnolia subgenus Magnolia, is closely related with Elmerrillia and sections Alcimandra and Aromadendron of Magnolia subgenus Magnolia; (3) the associates of Michelia are grouped with Magnolia subgenus Yulania and section Gynopodium of Magnolia subgenus Magnolia; (4) Pachylarnax forms a clade with sections Manglietiastrum and Gynopodium of Magnolia; (5) a well-supported Manglietia clade is recognized; (6) Caribbean species of section Theorhodon of Magnolia subgenus Magnolia, which are section Splendentes sensu Vázquez-Garcia, are closely allied with New World members of Magnolia subgenus Talauma; and (7) section Rytidospermum of Magnolia subgenus Magnolia and subgenus Talauma are polyphyletic. The separated clades in the molecular tree are considerably different from traditional taxonomic dispositions in the family. The molecular data strongly suggest that a taxonomic realignment of infrafamilial delimitations and compositions should be considered.

Journal Article↗

Diffuse alveolar hemorrhage in lupus nephritis.

AIM: Diffuse alveolar hemorrhage (DAH) is a rare and catastrophic event in systemic lupus erythematosus (SLE) with a high mortality rate, and little information is available about the degree of renal involvement in this condition. PATIENTS AND METHODS: To evaluate the effects of renal impairment on the course of DAH, the hospital records of 7 patients (9 episodes) with DAH and SLE between 1988 and 1998 at Seoul National University Hospital were reviewed. A diagnosis of DAH was established when the patient had an acute pulmonary syndrome including either hemoptysis, new alveolar infiltrates on the chest radiograph, the presence of a falling hematocrit or hemorrhagic BAL. All patients were women and their median age was 26 years ranging between 23 and 39. All patients had concurrent lupus nephritis and 4 of them were classified as WHO class IV with renal pathology. RESULTS: Their median serum creatinine level at the time of DAH was 4.6 mg/dl (0.8 - 13.6), and the median daily proteinuria amount was 778 mg (436 - 6200). All of the patients received corticosteroid therapy, and intravenous cyclophosphamide was given to 3 cases. Hemodialysis was done in 3 cases, and 4 of the 7 patients died during an acute event. We reviewed five series about the clinical parameters, including the serum creatinine level, treatment and hospital outcome. From the results of the analysis, it was determined that concomitant infection (RR 4.2) and the use of mechanical ventilation (RR 6.1) were associated with the increased risk of mortality, but azotemia (sCr > 3.0 mg/dl) (RR 1.5) or hemodialysis therapy (RR 1.3) was not shown to have a significant association. CONCLUSION: It could be suggested that even though renal failure is combined with DAH in SLE patients, the same aggressive treatment results in a comparable outcome as patients with normal renal function.

Acute Disease↗

Clinical significance of the fractional excretion of anions in metabolic acidosis.

The fractional excretion of anions has been proposed as a new index for the differential diagnosis of metabolic acidosis, identifying the properties of the conjugate base by examining the renal handling of the anion. Here, we investigated clinical significance of the fractional excretion of anions in pathophysiologic diagnosis of metabolic acidosis by measuring urine ammonium (NH4+) excretion, the ratio of A plasma anion gap/delta plasma HCO3- concentration (deltaAG/deltaHCO3-), and fractional excretion of anions in three different groups of metabolic acidosis: acid overproduction (8 patients with lactic acidosis, 8 with diabetic ketoacidosis, 3 with hippuric acidosis following glue sniffing), acid underexcretion (10 patients with chronic renal failure) and normal controls (10 normal volunteers who underwent 3-day NH4Cl loading). As expected, urine NH4+ excretion was higher in overproduction acidosis than in acid-loaded normal controls (88.1 +/- 12.3 vs. 54.0 +/- 3.7 mmol/day, p < 0.05), and it was lower in chronic renal failure than in acid-loaded normal controls (12.8 +/- 1.7 vs. 54.0 +/- 3.7 mmol/day, p < 0.05). The fractional excretion of anions had no difference between overproduction acidosis and chronic renal failure (41.2 +/- 42.8% vs. 41.0 +/- 8.1%). However, the fractional excretion of anions showed significant differences between the subgroups in acid overproduction (lactic acidosis, 4.7 +/- 0.3%; diabetic ketoacidosis, 45.8 +/- 3.1%; hippuric acidosis, 126.0 +/- 14.4%; p < 0.05). The ratio of plasma deltaAG/deltaHCO3- also exhibited significant differences between the subgroups in acid overproduction (lactic acidosis, 1.5 +/- 0.1; diabetic ketoacidosis, 1.0 +/- 0.1; hippuric acidosis, 0.3 +/- 0.1; p < 0.05). There was an inverse linear correlation between the fractional excretion of anions and the ratio of plasma deltaAG/deltaHCO3- (r2 =-0.89, p < 0.05). In conclusion, determination of the fractional excretion of anions may provide a useful clue to the differential diagnosis of metabolic acidosis caused by acid overproduction.

Acidosis↗

Renal biopsy in elderly patients: clinicopathological correlation in 117 Korean patients.

AIM: In the elderly with renal disease, the clinical presentations are frequently inconsistent with the pathologic findings. We tried to clarify the differences in pathological findings between the young and the elderly, in Korea and in Western countries, and the usefulness of a percutaneous renal biopsy in the elderly with renal disease. PATIENTS AND METHODS: We analyzed the clinical presentations and spectrums of renal histopathology by reviewing medical records and renal biopsy reports retrospectively in 117 Korean patients aged 60 years or more with renal disease. RESULTS: 85 patients had primary renal disease. The remaining 32 patients had renal diseases associated with systemic conditions. Out of the 85 patients with primary renal disease, 61 cases presented as idiopathic nephrotic syndrome. Compared with renal biopsy results of younger adult patients (age 15-59, n = 1,908), membranous nephropathy, crescentic glomerulonephritis, membranoproliferative glomerulonephritis, amyloidosis, light chain disease, and thrombotic thrombocytopenic purpura were more prevalent, but IgA nephropathy and lupus nephritis were less common in the elderly patients. In clinical presentation, nephrotic syndrome and rapidly progressive renal failure were more prevalent, but asymptomatic urinary abnormality was less common in elderly patients. The responsiveness to treatment was good in elderly patients with minimal-change lesion (complete remission in all patients) but poor in crescentic glomerulonephritis, IgA nephropathy, and membranoproliferative glomerulonephritis. From the above findings, the clinical presentation, patterns of histopathology and responsiveness to treatment of elderly Korean patients were similar to those of the younger Korean control group and the Western elderly group. CONCLUSION: Percutaneous renal biopsy is a useful diagnostic aid and can be used as a therapeutic guideline even in elderly patients with renal disease.

Aged↗

Differential expression of various cytokine and chemokine genes between proliferative and non-proliferative glomerulonephritides.

BACKGROUND: Intraglomerular cellular proliferation is one of the major determinants for dividing various glomerulonephritis (GN) into two groups, such as proliferative versus non-proliferative. Cytokines and chemokines are involved in the pathogenetic pathways and would affect the functional and histologic sequelae. We hypothesized that the morphological difference might be based on the differential intrarenal expression of various cytokines and chemokines. We quantified the intrarenal gene expression of various cytokines and chemokines, and correlated it with clinical parameters. METHODS: Total RNA was extracted from 54 proliferative GN (PGN) core biopsy specimens and 42 non-proliferative GN (NPGN) specimens. Using the internal competitors, RT-PCR was instituted to quantify mRNAs. RESULTS: The magnitude of the gene expressions of IL-2, IFN-gamma, and IFN-gamma/IL-10 ratio were significantly higher in PGN than in NPGN. RANTES and IL-8 had more abundant gene messages in PGN. It was shown that Th1 cytokine was upregulated if GN was mediated by immune complexes regardless of cellular proliferation. But chemokines had the elevated levels of expression in PGN among immune complex-mediated GN. Up-regulation of the IFN-gamma/IL-10 ratio and TNF-alpha was associated with poor renal function at the time of biopsy. Renal tissues from the patients with a non-nephrotic range of proteinuria showed abundant messages for proinflammatory cytokines and chemokines. CONCLUSION: Th1, proinflammatory cytokines, and chemokines were more abundant in proliferative GN, and correlated with unfavorable clinical parameters. We propose that the clinical manifestations and diverse histologic features of human GN are associated with differential expressions of specific cytokines and chemokines.

Adolescent↗

Investigation of the reaction pathway of OH radicals produced by Fenton oxidation in the conditions of wastewater treatment.

Abstract Fenton reaction has been often used to treat industrial wastewater or landfill leachate. However, most mechanistic research into the Fenton reaction has been confined to low concentration conditions (usually the concentration of iron is less than 1 mM). These conditions are removed from the circumstances of real application. This is especially true in the treatment of landfill leachate in Korea. Therefore, we investigated the characteristics of the Fenton system using high concentrations of iron (mostly [Fe2+] = 1 approximately 10 mM, [H2O2] = 5 mM, [Organic (t-BuOH or methanol)] = 0 or 30 mM) and interpreted the results from the known reaction mechanisms of the Fenton system. As a result, the use of high ferrous ion (> or = 1 mM) is believed to be appropriate for producing large quantities of OH. within a short period of time, causing fast consumption of hydrogen peroxide. However, OH. scavenging by the ferrous ion, the changes of oxidation products due to the oxygen depleted conditions, and the precipitation effect of ferric ion must be considered for the successful application of Fenton reaction. On the other hand, in low ferrous ion (<1 mM), it is important to utilize the redox cycles of iron in an effective manner.

Chemical Precipitation↗

Delayed graft function. Influence on outcome and strategies for prevention.

Delayed graft function remains a prevalent problem in cadaveric renal transplantation that increases rejection, decreases graft and patient survival, increases the cost of transplantation, and complicates patient management. Although current medical and surgical strategies can reduce the incidence of DGF to 20% or less, newer therapies that focus on nonimmune and immune forms of renal injury are needed to improve outcomes further.

Graft Rejection↗

Diagnosis and management of acute and chronic prostatitis.

Prostatitis syndromes are some of the most poorly understood yet prevalent problems in urology. There is little controversy over acute prostatitis, a urinary tract infection with systemic symptoms and signs that typically responds to antimicrobial therapy. By contrast, the chronic prostatitis syndromes have so far eluded attempts to understand their pathophysiology and design effective therapies, resulting in great frustration among patients and health care providers. An accurate diagnosis and a multidisciplinary approach are essential to assist men with this often debilitating condition.

Acute Disease↗