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Biomedical subjects

J H Song

Publications and source records attributed to J H Song.

At least 37 records · Page 2Linked to original sources
PubMed2001

Peripheral blood mitochondrial DNA content is inversely correlated with insulin secretion during hyperglycemic clamp studies in healthy young men.

Abnormalities in mitochondrial DNA(mtDNA) have been implicated in the pathogenesis of diabetes mellitus. We recently reported that decreased mtDNA content precedes the development of diabetes mellitus and is associated with parameters of insulin resistance. In this study, we examined whether there is any relation between mtDNA content and insulin secretion. We compared the mtDNA content of peripheral blood leukocytes with the parameters of insulin secretion measured by hyperglycemic clamp in a group of healthy young men. There were statistically significant correlations between mtDNA content in peripheral blood and fasting plasma insulin (r=-0.43, P<0.05) and C-peptide levels (r=-0.44, P<0.05). MtDNA content also correlated negatively with acute insulin response(r=-0.48, P<0.05), late insulin response (r=-0.50, P<0.05) during hyperglycemic clamp and insulin secretion after glucagon stimulation (r=-0.60, P<0.01). mtDNA content in peripheral blood correlated negatively with homeostasis model (HOMA) insulin resistance (r=-0.45, P<0.05) although it did not correlate with the insulin insensitivity index (M/I) during hyperglycemic clamp. In summary, the mtDNA content of peripheral blood correlated negatively with indices of insulin resistance and insulin secretion in healthy young men. The compensatory response of pancreas beta cells to insulin resistance might contribute in part to increased insulin secretion in these subjects.

Adult↗
PubMed2001

Effects of fetal bovine serum on ferrous ion-induced oxidative stress in pheochromocytoma (PC12) cells.

Ferrous ion (Fe2+) has been considered to be a cause of neuronal oxidative injury. Since body fluids contain protein and serum is an essential component of tissue culture medium, we have examined the role of serum protein on Fe2+-mediated oxidative stress using PC12 cells and rat cerebral cortices. Fe2+ or the combination of ascorbate and Fe2+ increased concentrations of thiobarbituric acid reactive substances (TBARS) in PC12 cells and cerebrocortical homogenates in medium (RPMI 1640), but did not increase TBARS when the medium was supplemented with 10% fetal bovine serum. Treatment with ascorbate/Fe2+ in serum-free medium reduced endogenous glutathione (GSH) concentration in PC12 cells. However, the medium supplemented with serum did not reduce GSH concentrations. PC12 cell death induced by ascorbate/Fe2+ was alleviated by increasing serum or bovine albumin concentrations in the medium. These observations indicated that oxidative injury caused by the transition metal ion could be lessened by adding fetal bovine serum to culture medium.

Animals↗
PubMed2001

Assessment of total body water from anthropometry-based equations using bioelectrical impedance as reference in Korean adult control and haemodialysis subjects.

BACKGROUND: Several indirect prediction equations to estimate total body water (TBW) with simple demographic and anthropometric data are commonly used by researchers and dialysis units. These equations are largely based on observations in subjects of the Western hemisphere. The purpose of this study was to investigate the possible application of anthropometry-based TBW equations to a Korean adult control population and maintenance haemodialysis (HD) patients using multifrequency bioelectrical impedance analysis (BIA) as reference. METHODS: We performed BIA and anthropometric measurements in 67 healthy adults and 101 HD patients. Four anthropometry-based equations were used: 58% of actual body weight (TBW-58), the Watson formula (TBW-W), the Hume formula (TBW-H), and the Chertow formula (TBW-C). Multifrequency BIA was performed at fasting state in controls and after HD. RESULTS: TBW-BIA was 34.6+/-6.9 l in control and 29.9+/-5.1 l in HD patients. TBW-58 and TBW-C gave significantly greater TBWs than TBW-BIA in both control and HD subjects. The correlation coefficients of TBW-BIA with calculated TBWs were lowest in TBW-58 (0.754 in control and 0.856 in HD subjects), and highest in TBW-C (0.944 in control and 0.916 in HD subjects). Mean prediction error was greatest in the Chertow formula for control and HD patients. Mean prediction error, limits of agreement, and root mean square error were lowest between TBW-BIA and TBW-H in control and between TBW-BIA and TBW-W in HD subjects. The correlation coefficient in the Bland-Altman plot was closer to zero and parallel with TBW-W than TBW-H in control and HD subjects. CONCLUSION: Currently available TBW equations overestimate TBW in both Korean normal control subjects and HD patients. Among them, the Watson formula appears to be the closest to TBW and to have the least bias. Based on this analysis, it is reasonable to use the Watson formula for the calculation of TBW in Korean adult control and HD subjects until an Asian-based TBW equation is available.

Adult↗
PubMed2001

Bladder tumor detection at virtual cystoscopy.

PURPOSE: To investigate the utility of computed tomographic (CT) virtual cystoscopy in the detection of bladder tumors. MATERIALS AND METHODS: Twenty-six patients suspected or known to have bladder neoplasms underwent CT virtual and conventional cystoscopy. The bladder was insufflated with carbon dioxide through a Foley catheter. Helical CT of the bladder was then performed. The data were downloaded to a workstation for interactive intraluminal navigation. Two radiologists blinded to the results of conventional cystoscopy independently reviewed the transverse and virtual images, with consensus readings for cases with discrepant results. RESULTS: Thirty-six (90%) of 40 bladder lesions proved at conventional cystoscopy were detected with a combination of transverse and virtual images. Four (10%) of 40 bladder lesions, all smaller than 5 mm, were undetected. Transverse and virtual images were complementary, since six polypoid lesions smaller than 5 mm depicted on the virtual images were not seen on the transverse images. In contrast, areas of wall thickening were more readily appreciated on transverse images. CT with patients in both supine and prone positions was necessary, since seven (19%) and five (14%) of 36 lesions were seen only on supine and prone images, respectively. CONCLUSION: CT virtual cystoscopy is a promising technique for use in bladder tumor detection of lesions larger than 5 mm. Optimal evaluation requires adequate bladder distention with the patient in both supine and prone positions and interpretation of both transverse and virtual images.

Adult↗
PubMed2001

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↗
PubMed2001

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↗
PubMed2001

Fatal pulmonary-renal syndrome manifested with immune complex crescentic glomerulonephritis in a patient with MPO-ANCA seropositivity.

Recent reports have indicated that a significant number of immune complex glomerulonephritis (GN) cases are associated with antineutrophilic cytoplasmic antibody (ANCA). However, most of the reported cases were associated with underlying primary glomerular diseases. When primary glomerular diseases were not found, immune deposits tended to be non-specific and the level of ANCA is usually borderline. We report here upon a case of life-threatening pulmonary-renal syndrome manifested simultaneously with immune complex GN and myeloperoxidase (MPO)-ANCA seropositivity. A 29- year-old man was admitted with pulmonary hemorrhage and rapidly progressing renal dysfunction. On admission, ANCA revealed perinuclear staining with a titer of 1:160. The MPO-ANCA level was 59 IU by ELISA. Other serologic markers including ANA, anti-DS-DNA and anti-GBM Ab were negative. Renal biopsy showed cellular crescents in eight of 18 glomeruli. Immunofluorescence staining showed strong granular deposits of C3, C1q, IgG and IgM in the capillary loop and the mesangium. Electron microscopy showed multifocal electron dense deposits scattered in the mesangium, paramesangium, and the subendothelial and subepithelial areas. The patient initially responded to steroid and cyclophosphamide. MPO-ANCA decreased to less than 10 IU. Twenty three days after hospital discharge, the patient was re-admitted urgently with fever, generalized papulonodular skin lesions, and a recurrence of massive pulmonary hemorrhage and renal dysfunction. He died from uncontrolled pulmonary hemorrhage and respiratory insufficiency. P-ANCA titer and MPO-ANCA level at the second admission were 1:320 and 82 U/ml respectively. Interestingly, relapse was shown to be triggered by varicella zoster infection.

Adult↗
PubMed2001

Incisional hernia after corrective omentectomy for peritoneal dialysis catheter malposition.

Laparotomic correction with or without omentectomy is occasionally required for malposition of a peritoneal dialysis (PD) catheter. We reviewed the incidence of incisional hernia following laparotomic PD catheter correction with or with omentectomy. From January 1996 to December 1998, PD catheters were implanted by non open-dissection technique using a trocar in 148 patients. Laparotomy for PD catheter malposition was required in 20 of the 148 patients. Omentectomy was performed simultaneously in 11 patients. After laparotomy, the wound was closed with interrupted or continuous layered polyglycolidelactide polymer sutures. Dialysis was resumed after the third or fourth day. Incisional hernia developed in 30% (6/20) of all patients undergoing laparotomy, but in none of the patients not undergoing laparotomy. The incidence increased when omentectomy was performed [5/11 (45.5%) vs 1/9 (11.1%)]. Multiparity, female sex, and laparotomy at a later time also predisposed to development of incisional hernia. Among the patients with incisional hernia, 2 patients showed multiple recurrences and 1 patient showed later leakage; PD catheters were lost in these patients. Another 3 patients continued continuous ambulatory peritoneal dialysis (CAPD) without a recurrence. The results suggest that incisional hernia is prevalent following laparotomic PD catheter correction, especially when omentectomy is performed simultaneously. Situations that seem to increase the risk of incisional hernia--inevitably encountered during corrective laparotomic omentectomy--are discussed. An evaluation is necessary concerning whether omentectomy acts as an independent risk factor for incisional hernia, and whether incisional hernia occurs more frequently when omentectomy is performed after a period on CAPD as compared with when it is performed at the time of PD catheter implantation. Laparotomic omentectomy should be performed as a last resort for the correction of PD catheter malposition.

Adolescent↗
PubMed2000

The effects of ascorbic acid on dopamine-induced death of PC12 cells are dependent on exposure kinetics.

The role of ascorbic acid on dopamine (DA) oxidation-mediated cytotoxicity was studied using the PC12 cell line. DA cytotoxicity was slightly attenuated by ascorbic acid, whereas the cytotoxicity of 6-hydroxydopamine (6-OHDA), a DA oxidation product, was markedly potentiated. To elucidate the relationship between the ascorbic acid effect and the degree of DA oxidation, ascorbic acid was added in a time-dependent fashion after DA treatment. We found greater cell death the later ascorbic acid was applied. Treatment of cells with glutathione alleviated DA- and 6-OHDA-induced cell death, while L-buthionine sulfoximine potentiated DA and 6-OHDA cytotoxicity. Ascorbic acid combined with glutathione eliminated the toxicity of DA and 6-OHDA. These results suggest that the interaction between DA and ascorbic acid is dependent upon the degree of DA oxidation and glutathione availability.

Animals↗
PubMed2000

Amitriptyline modulation of Na(+) channels in rat dorsal root ganglion neurons.

The effects of amitriptyline, a tricyclic antidepressant, on tetrodotoxin-sensitive and tetrodotoxin-resistant Na(+) currents in rat dorsal root ganglion neurons were studied using the whole-cell patch clamp method. Amitriptyline blocked both types of Na(+)currents in a dose-and holding potential-dependent manner. At the holding potential of -80 mV, the apparent dissociation constants (K(d)) for amitriptyline to block tetrodotoxin-sensitive and tetrodotoxin-resistant Na(+) channels were 4.7 and 105 microM, respectively. These values increased to 181 and 193 microM, respectively, when the membrane was held at a potential negative enough to remove the steady-state inactivation. Amitriptyline dose-dependently shifted the steady-state inactivation curves in the hyperpolarizing direction and increased the values of the slope factors for both types of Na(+) channels. The voltage dependence of the activation of both types of Na(+) channels was shifted in the depolarizing direction. It was concluded that amitriptyline blocked the two types of Na(+) channels in rat sensory neurons by modulating the activation and the inactivation kinetics.

Amitriptyline↗
PubMed2000

ATP evokes different currents in TTX-sensitive and TTX-resistant cells of dorsal root ganglia.

The relationship between the level of expression of tetrodotoxin-sensitive (TTX-S) and tetrodotoxin-resistant (TTX-R) sodium currents and the occurrence of two kinetically different ATP-induced currents in rat dorsal root ganglion neurons was studied. ATP evoked two distinct types of currents, one with fast activation and desensitization (I-fast) and the other with slow and persistent development (I-slow). In all TTX-S cells which expressed solely TTX-S sodium currents ATP evoked I-fast. The other cells expressed a variable proportion of TTX-S and TTX-R sodium currents. Only 15% of these TTX-R+S cells responded to ATP with I-fast. I-slow was evoked in both cell types but the magnitude of response was much greater in TTX-R+S cells. This result suggests that a different array of ion channels is equipped in different types of sensory neurons.

Adenosine Triphosphate↗
PubMed2000

Cloning of a sesquiterpene cyclase and its functional expression by domain swapping strategy.

Sesquiterpene cyclase, the first committed step enzyme from the general isoprenoid building block farnesyl pyrophosphate (FPP) for the synthesis of phytoalexin capsidiol, was isolated from the UV-C treated leaves of Capsicum annuum. This sesquiterpene cyclase, termed as CASC2 showing 77% amino acid identity with the previously cloned sesquiterpene cyclase CASC1, was composed of 560 amino acids with a calculated molecular mass of 64,907. The mRNA expression pattern of CASC2 was very similar to that of CASC1 during the time course of UV-C irradiated leaves of pepper on RNA blot analysis by using each specific probe. The heterologous expression in Escherichia coli using the CASC2 full length failed; however the chimeric construct of CASC2 in which the amino terminal 164 amino acid substituted by the equivalent portion of either CASC1 or tobacco sesquiterpene cyclase was capable of expressing the functional sesquiterpene cyclase activities. The radio-labeled enzymatic products catalyzed by the partially purified chimeric CASC2 were comigrated with authentic radio-labeled sesquiterpene on thin layer chromatography.

Amino Acid Sequence↗
PubMed2000

Lateral tegmental field neurons with activity correlated to the 10-Hz rhythm in sympathetic nerve discharge.

Neurons in the lateral tegmental field (FTL) has been previously reported to have activity only minimally correlated (< 1% of neurons tested) with the 10-Hz rhythm of the slow wave of the sympathetic nerve discharge. We report here that 10% of the neurons recently tested in the FTL could be shown to correlate with the 10-Hz rhythm. The neuron-to-nerve coherence is weaker than in other medullary areas, but is nonetheless significant.

Animals↗
PubMed2000

Protective effect of boldine on oxidative mitochondrial damage in streptozotocin-induced diabetic rats.

Increased oxidative stress has been suggested to be involved in the pathogenesis and progression of diabetic tissue damage. Several antioxidants have been described as beneficial for oxidative stress-associated diseases. Boldine ([s]-2,9-dihydroxy-1, 10-dimethoxyaporphine) is a major alkaloid found in the leaves and bark of boldo (Peumus boldus Molina), and has been shown to possess antioxidant activity and anti-inflammatory effects. From this point of view, the possible anti-diabetic effect of boldine and its mechanism were evaluated. The experiments were performed on male rats divided into four groups: control, boldine (100 mg kg(-1), daily in drinking water), diabetic [single dose of 80 mg kg(-1)of streptozotocin (STZ), i.p.] and diabetic simultaneously fed with boldine for 8 weeks. Diabetic status was evaluated periodically with changes of plasma glucose levels and body weight in rats. The effect of boldine on the STZ-induced diabetic rats was examined with the formation of malondialdehydes and carbonyls and the activities of endogenous antioxidant enzymes (superoxide dismutase and glutathione peroxidase) in mitochondria of the pancreas, kidney and liver. The scavenging action of boldine on oxygen free radicals and the effect on mitochondrial free-radical production were also investigated. The treatment of boldine attenuated the development of hyperglycemia and weight loss induced by STZ injection in rats. The levels of malondialdehyde (MDA) and carbonyls in liver, kidney and pancreas mitochondria were significantly increased in STZ-treated rats and decreased after boldine administration. The activities of mitochondrial manganese superoxide dismutase (MnSOD) in the liver, pancreas and kidney were significantly elevated in STZ-treated rats. Boldine administration decreased STZ-induced elevation of MnSOD activity in kidney and pancreas mitochondria, but not in liver mitochondria. In the STZ-treated group, glutathione peroxidase activities decreased in liver mitochondria, and were elevated in pancreas and kidney mitochondria. The boldine treatment restored the altered enzyme activities in the liver and pancreas, but not the kidney. Boldine attenuated both STZ- and iron plus ascorbate-induced MDA and carbonyl formation and thiol oxidation in the pancreas homogenates. Boldine decomposed superoxide anions, hydrogen peroxides and hydroxyl radicals in a dose-dependent manner. The alkaloid significantly attenuated the production of superoxide anions, hydrogen peroxide and nitric oxide caused by liver mitochondria. The results indicate that boldine may exert an inhibitory effect on STZ-induced oxidative tissue damage and altered antioxidant enzyme activity by the decomposition of reactive oxygen species and inhibition of nitric oxide production and by the reduction of the peroxidation-induced product formation. Boldine may attenuate the development of STZ-induced diabetes in rats and interfere with the role of oxidative stress, one of the pathogeneses of diabetes mellitus.

Animals↗
PubMed2000

A co-operative study: clinical characteristics of 334 Korean patients with moyamoya disease treated at neurosurgical institutes (1976-1994). The Korean Society for Cerebrovascular Disease.

A co-operative study was conducted to determine the clinical characteristics of patients with moyamoya disease who were diagnosed and treated at neurosurgical institutes in Korea before 1995. Twenty-six hospitals contributed 505 cases and among them, the clinical characteristics of 334 patients with definite moyamoya disease were evaluated. The number of patients began to increase from the late 1980s, and after that approximately 20 patients were treated each year. There were two age peaks: from six to 15 and from 31 to 40 years of age. Haemorrhagic manifestations occurred in approximately 43% of the patients. The major clinical manifestations were haemorrhage in adults (62.4%) and ischaemia in children (61.2%). Overall 54.5% of the patients experienced decreased consciousness levels, mainly due to intracranial haemorrhage or cerebral infarction. In the patients with ischemic manifestations, the adult patients were more likely to have cerebral infarction than the pediatric patients (80% vs. 39%) and the pediatric patients were more likely to have TIA (61% vs. 25%). Thirty eight percent of the patients underwent bypass surgery and 53% of these procedures were performed bilaterally. Treatment policies, including indications for bypass surgery and commonly used drugs, were somewhat different according to the institution. Overall favorable outcome was 73%, and the most significant factor affecting poor outcome was haemorrhagic manifestation. This article describes the characteristics of 334 patients with moyamoya disease, who were diagnosed and treated at neurosurgical institutes in Korea before 1995.

Adolescent↗
PubMed2000

Effect of dialysis modalities on gastric myoelectrical activity in end-stage renal disease patients.

Gastric motility is controlled by gastric myoelectrical activity, which propagates from the proximal body to the distal antrum at a frequency of 3 cycles/min. In uremic patients, dyspeptic symptoms are common. To investigate whether dialysis modality affects gastric myoelectrical activity in uremic patients, we performed electrogastrography (EGG) in 41 patients without diabetes with end-stage renal disease (ESRD) undergoing hemodialysis (HD; n = 22) and continuous ambulatory peritoneal dialysis (CAPD; n = 19). EGG was performed noninvasively using abdominal surface electrodes in the fasting state before and 4 hours after HD and at empty and 2 hours after CAPD with 2,000 mL of dialysate. There were no significant differences in age, sex, body weight, duration of dialysis, and percentage of patients with upper gastrointestinal (UGI) symptoms (63.6% versus 42.1%). CAPD patients had significantly lower serum albumin levels (3.4 +/- 0.4 versus 3.9 +/- 0.4 g/dL; P < 0.05), greater serum total-cholesterol levels (189 +/- 33 versus 157 +/- 36 mg/dL; P: < 0.05), and greater percentages of patient with early satiety (42.1% versus 13.6%; P < 0.05) than HD patients. Dominant power significantly increased after HD (251.3 +/- 157.5 versus 512.9 +/- 390.0 dB; P < 0.05) but seemed to decrease after CAPD without statistical significance (416.2 +/- 323.6 versus 283.8 +/- 280.7 dB). There was no difference in the normal slow-wave frequency (NSWF) between HD and CAPD patients (predialysis, 60.7% +/- 29.3% versus 52.2% +/- 36.7%; postdialysis, 56.3% +/- 32.0% versus 50.9% +/- 34.2%). Tachygastria significantly increased after CAPD (pre-CAPD, 2.35% +/- 4.3% versus post-CAPD, 10.0% +/- 14.8%; P < 0.05). There was a significant correlation between changes in tachygastria after CAPD and grade of early satiety in CAPD patients with UGI symptoms (r = 0.74; P: < 0.05). Changes in NSWF after CAPD significantly correlated with age (r = -0.51; P: < 0.05). In conclusion, dialysis modalities seem to have different effects on gastric myoelectrical activity in patients with ESRD.

Female↗