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Biomedical subjects

H Y Song

Publications and source records attributed to H Y Song.

At least 37 records · Page 2Linked to original sources

Infestation status of head louse and treatment with lindane shampoo in children of primary school and kindergarten in Chinju-shi, Kyongsangnam-do, Korea.

The infestation status of head louse among children attending primary schools and kindergartens in Chinju-shi, Kyongsangnam-do, Korea, was investigated between June and July 1999. Out of 2,288 children examined, 3.9% of boys (48/1,242) and 23.5% of girls (246/1,046) were infested with nits or adult/nymphs of lice. The effectiveness of lindane shampoo (1% gamma benzene hexachloride solution) was evaluated after one or two time applications to all the children infested. The negative conversion rate of pediculosis was 93.5%. Effective control measures are needed to control and prevent such ectoparasite infestation amongst children.

Animals↗

The prevalence and associated risk factors of renal artery stenosis in patients undergoing cardiac catheterization.

Renal artery stenosis may be a cause of hypertension and a potential contributor to progressive renal insufficiency. However, the prevalence of renal artery disease in a general population is poorly defined. The purposes of this study were to evaluate the prevalence of angiographically-determined renal artery narrowing in a patient population undergoing routine cardiac catheterization, and to identify the risk factors for renal artery stenosis. After left ventriculography, abdominal aortography was performed to screen for the presence of renal artery stenosis. A total of 427 patients (274 males, 153 females) were studied and the mean age was 59 years. Renal artery narrowing was identified in 10.5% of patients. Significant (> or = 50% diameter narrowing) renal artery stenosis was found in 24 patients (5.6%) and insignificant stenosis was found in 21 patients (4.9%). Significant unilateral stenosis was present in 4.2% of patients and bilateral stenosis was present in 1.4%. The stem of the renal artery was a more common site of stenosis in 62.2% of patients than in the ostium (37.8%), but the severity of stenosis was not significantly different according to the site of stenosis. By univariate and multivariate logistic regression analysis, the association of clinical variables with renal artery stenosis was assessed. Multivariable predictors included age, hypertension and peripheral vascular disease (p < 0.05). The variables such as sex, smoking history, hyperlipidemia, renal insufficiency, as well as the presence of obesity, severity of coronary heart disease and D.M., were not associated. In conclusion, the prevalence of angiographically-determined renal artery narrowing in a patient population undergoing cardiac catheterization is 10.5%. Old age, hypertension and evidence of peripheral vascular disease represent the predictors of renal artery stenosis.

Adult↗

Human insulin B chain but not A chain decreases the rate of diabetes in BB rats.

The autoimmune response seen in insulin-dependent diabetes mellitus (IDDM) includes a humoral immune response against human insulin. Early insulin treatment has been used to prevent IDDM in the rodent models of IDDM, and a prevention trial is underway in humans. The metabolic effects of insulin may not be involved in this prevention since, in NOD mice, the use of metabolically inert human insulin B chain was effective. We wished to ascertain whether immunization of diabetes-prone BB/W rats with insulin B chain, A chain, or both could alter the incidence of diabetes. Immunizations began by 30 days of age and the rats were followed until 120 days of age. Only immunization with insulin B chain plus adjuvant was effective in reducing the rate of diabetes. All immunization frequencies were effective, but a significantly lower rate of diabetes was achieved with injections every week. All of the doses tested resulted in significantly lower rates of diabetes. These data confirm in the BB rat model that immunization with insulin B chain in the presence of adjuvant can reduce diabetes incidence. The absence of any metabolic effect of B chain and the requirement for adjuvant suggest that this effect is mediated via modulation of the autoimmune response.

Animals↗

Portal vein embolization with use of a new liquid embolic material: an experimental study.

PURPOSE: To evaluate the efficacy and safety of a new liquid embolic material in portal vein embolization (PVE). MATERIALS AND METHODS: A new embolic material (Embol) was percutaneously injected into the left portal vein of 13 swine, using a balloon catheter to prevent reflux. The swine were killed immediately (n = 6), 2 weeks (n = 4), and 4 weeks (n = 3) after the PVE, and the volumes of the right and left lobes were measured. The changes in body temperature, aspartate aminotransferase (AST) (formerly SGOT), alanine aminotrasferase (ALT) (formerly SGPT), and bilirubin levels after the PVE were studied, and the histopathologic changes in the embolized and nonembolized lobes were examined with light microscopy. RESULTS: The average volume ratio of the right:left lobe immediately after the PVE was 55(+/-2):45(+/-1), and changed to 71(+/-3):29(+/-3) at 2 weeks and 82(+/-3):18(+/-3) at 4 weeks after embolization. There were only mild changes in AST, ALT, and bilirubin levels, and only one pig showed a significant elevation in body temperature after PVE. Microscopically, the embolized lobe showed contraction of hepatocyte without any sign of necrosis and the nonembolized lobe expansion of hepatocyte. CONCLUSIONS: The new embolic material seems effective and safe for PVE.

Animals↗

Percutaneous hot saline injection therapy: effectiveness in large hepatocellular carcinoma.

PURPOSE: To report on the efficacy of percutaneous hot saline injection therapy (PSIT) in the treatment of large hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Twenty-nine patients with 31 HCCs underwent PSIT. Physiologic saline was mixed with contrast medium and Lipiodol; this mixture was boiled and injected into the tumor. Mean tumor diameter was 7.0 cm. Initial regression rates were evaluated at 3-month interval with computed tomography (CT) and alpha-fetoprotein level measurement. Cumulative survival rates were calculated with the Kaplan-Meier method. Multivariate analysis using Cox's proportional hazard regression model was performed to determine the significant prognostic factors. RESULTS: Initial regression rate for all tumors at a 3-month interval was 42% (13 of 31 tumors) and the median survival was 10.0 months (range, 3.0-36.0 months). The significant prognostic factors were encapsulated tumors, tumors less than 10 cm in diameter, tumors with even saline dispersion, tumors with initial regression at 3-month follow-up, and TNM stage II or III rather than IV. CONCLUSION: PSIT is a feasible alternative treatment for a large HCC when transcatheter arterial chemoembolization is not feasible or has failed.

Adult↗

Tracheobronchial strictures: treatment with a polyurethane-covered retrievable expandable nitinol stent--initial experience.

A polyurethane-covered retrievable expandable stent was placed in 13 patients with tracheobronchial strictures. In four patients with benign strictures, the stent was removed with use of a retrieval hook 2-6 months after placement. After stent removal, three of the four patients did not need further treatment. The retrievable stent warrants further investigation in the treatment of tracheobronchial strictures.

Adult↗

Hepatic falciform artery: is prophylactic embolization needed before short-term hepatic arterial chemoinfusion?

OBJECTIVE: The purpose of this study was to assess the need for prophylactic embolization of the hepatic falciform artery (HFA) to prevent supraumbilical skin rash before short-term hepatic arterial chemoinfusion with or without subsequent embolization. MATERIALS AND METHODS: Transcatheter arterial chemoinfusions or chemoembolizations were performed on 127 consecutive patients with hepatocellular carcinoma between August 1997 and September 1997. Hepatic angiography findings regarding the anatomic variations of the hepatic artery and the presence and origin of the HFA were analyzed. The patients were followed up for 35-143 days (mean, 78 days). The incidence of supraumbilical skin rash was assessed for two groups of patients, those with an HFA and those without. We also evaluated other factors that seemed closely related to the presence of an HFA. RESULTS: An HFA was identified in 16 (13%) of 127 patients. Each HFA originated either in the left hepatic artery (n = 14) or the middle hepatic artery (n = 2). In the 16 patients with an HFA, serum bilirubin levels were significantly higher than in patients without one (p < .05), whereas serum albumin levels and prothrombin times were significantly lower (p < .05) and more prolonged (p = .02) than in patients without one. Portal venous collateral vessels were more frequently seen in patients with an HFA (50%) than in those without one (31%), but the frequency was not significant (p = .157). However, supraumbilical skin rash was not seen in any patient. CONCLUSION: We found no need for prophylactic embolization of the HFA to prevent supraumbilical skin rash before short-term hepatic arterial chemoinfusion with or without subsequent embolization.

Adult↗

Current status of peritoneal dialysis in Korea: efforts to achieve optimal outcome.

Since its introduction in 1981, peritoneal dialysis (PD) has become firmly established as an effective mode of renal replacement therapy and serves an increasing patient population in Korea. The latest registry data indicate that about 3700 end-stage renal disease patients are maintained on chronic PD, representing 24.1% of the country's dialysis population. The majority (93.3%) of these patients are on continuous ambulatory peritoneal dialysis (CAPD) using the two-bag disconnect system, while only 3.3% are on automated PD. Under current renal reimbursement policies, most dialysis patients have to pay 20% of dialysis fees. Thus CAPD patients on 4 x 2-L daily exchanges pay about US$200 per month, not including medication and travel costs. Traditionally, most PD centers in Korea have used the "standard" prescription of 4 exchanges of 2 L of solution for most of their patients. A recent survey of 1467 patients who commenced CAPD in 1997 revealed that 84% of these patients were initially prescribed 4 x 2-L exchanges, while 12% were given a daily volume of 6 L. With this standard prescription, the percentages of Korean CAPD patients initially achieving the adequacy target of Kt/V urea > or = 2.0 and standardized creatinine clearance (SCCr) > or = 60 L/week/1.73 m2, were 74.4% and 82.1%, respectively. It is likely that, among current Korean CAPD patients, a much lower percentage will achieve the clearance targets compared to this initial outcome, but the precise data are not available. However, it is not clear whether the levels of small-solute clearance recommended for optimal PD outcomes, and proposed by the NKF-DOQI guidelines, will bring the expected benefits to Korean patients. Overall survival of Korean PD patients appears to be as good as, or even better than, that in most other countries. Recently, a single large PD center reported patient survival of 92.1%, 85.6%, 81.4%, and 67.6% at 1, 2, 3, and 5 years respectively. Other centers also reported similar outcomes. As in other countries, cardiovascular deaths predominate among Korean patients: death was due to cardiac causes in 29%, to vascular causes in 21%, and to infectious causes in 24%. Peritonitis is the most important barrier to prolonged use of CAPD in Korea, and more PD patients transfer to hemodialysis because of peritonitis than in other countries. To further reduce the morbidity and mortality of Korean PD patients, various control measures need to be implemented that can reduce or prevent peritonitis and other infectious complications. Also, to further improve long-term patient outcome, Korean nephrologists need to establish and practice optimal clearance targets in the chronic care of these patients.

Cause of Death↗

Influence of apolipoprotein E genotype on lipid and lipoprotein levels in continuous ambulatory peritoneal dialysis patients.

Apolipoprotein (Apo) E has an important role in triglyceride (TG)-rich lipoprotein metabolism, and the genotype of Apo E is associated with premature coronary artery disease. Patients undergoing continuous ambulatory peritoneal dialysis (CAPD) develop various abnormalities of lipid metabolism and are prone to develop accelerated atherosclerosis. To investigate the distribution of Apo E genotype, and to evaluate the influence of Apo E polymorphism on lipid metabolism in CAPD patients, we measured Apo E genotypes, serum lipid, and lipoprotein levels in 54 CAPD patients (M:F = 1:1). The most common genotype of Apo E in the CAPD patients was E 3/3, found in 68.5%. The frequencies of the other genotypes were E 2/3, found in 14.8%, and E 4/3, found in 16.7%. No genotypic differences in Apo E were seen in the patients with regard to the presence of diabetes, the level of parathyroid hormone, or the transport characteristics of the peritoneal membrane. When comparing lipid levels by Apo E genotype, the total cholesterol and TG levels of E 2/3 patients were significantly higher than those of E 3/3 or E 4/3 patients. The differences in high-density or low-density lipoprotein cholesterol levels by Apo E genotype were not significant. In comparing lipoprotein levels by Apo E genotype, the Apo B and lipoprotein (a) levels of E 2/3 patients were significantly lower than those of E 3/3 or E 4/3 patients. In conclusion, the Apo E 3/3 genotype seems to be the most common genotype in CAPD patients, and the Apo E 2/3 genotype appears to be associated with high cholesterol and TG levels. These results demonstrate the need for further prospective studies in these subjects aimed at elucidating the impact of genetic variation at the Apo E locus on the development of atherosclerosis.

Apolipoproteins E↗

Lacrimal system obstruction treated with lacrimal polyurethane stents: outcome of removal of occluded stents.

PURPOSE: To describe the short- and long-term outcomes of the removal of occluded stents. MATERIALS AND METHODS: With fluoroscopic guidance, 571 lacrimal polyurethane stents were placed in 502 patients with epiphora due to obstruction of the lacrimal system. Of the 571 stents, 142 were removed 2 weeks to 42 months (mean, 7 months) after placement because of recurrent epiphora, and the lacrimal system was irrigated with saline solution through the lacrimal point. RESULTS: Stent removal was well tolerated. Mild epistaxis occurred in one patient and was controlled with a nasal pack. Recurrent epiphora was due to obstruction of the stent with mucoid material in 49 (35%) of 142 systems and granulation tissue in 93 (65%) systems. After stent removal, 73 (51%) of the 142 lacrimal systems showed improvement of epiphora, with a patent lacrimal system at 7-day follow-up dacryocystography. During the follow-up of 2 weeks to 49 months (mean, 22 months) after stent removal, patency was maintained in 24 (33%) of the 73 lacrimal systems. CONCLUSION: Removal of an occluded lacrimal plastic stent was easy and safe. Recurrent epiphora after placement of lacrimal plastic stents can be treated with removal of the occluded stents an irrigation with saline solution through the lacrimal point, which resulted in a patent lacrimal system in 33% of cases in this study.

Adult↗

Esophageal rupture during balloon dilation of strictures of benign or malignant causes: prevalence and clinical importance.

PURPOSE: To review the prevalence and clinical importance of esophageal rupture during balloon dilation for treatment of esophageal stricture. MATERIALS AND METHODS: Fluoroscopically guided esophageal balloon dilation was performed within 9 years in 96 consecutive patients with esophageal strictures. Esophageal rupture was classified into three types: type 1 was intramural; type 2, transmural; and type 3, transmural with mediastinal leakage. RESULTS: Each patient underwent one to seven procedures, for a total of 191 procedures. Esophageal rupture occurred in 20 patients (21%). Type 1 esophageal rupture occurred in eight patients, type 2 in 11, and type 3 in one. All esophageal ruptures were detected immediately after the procedure. Sixteen patients were treated with fasting, parenteral alimentation, and antibiotics; two were treated surgically; and two were treated with stent placement. No treatment-related deaths occurred. CONCLUSION: The overall prevalence of esophageal rupture was 21%. A substantial number of patients who developed type 1 rupture had associated clinical symptoms, such as pain and fever, but responded to conservative management and are thus included as having complications of esophageal balloon dilation.

Adolescent↗

Tumor necrosis factor (TNF)-mediated kinase cascades: bifurcation of nuclear factor-kappaB and c-jun N-terminal kinase (JNK/SAPK) pathways at TNF receptor-associated factor 2.

TNF-induced activation of the transcription factor NF-kappaB and the c-jun N-terminal kinase (JNK/SAPK) requires TNF receptor-associated factor 2 (TRAF2). The NF-kappaB-inducing kinase (NIK) associates with TRAF2 and mediates TNF activation of NF-kappaB. Herein we show that NIK interacts with additional members of the TRAF family and that this interaction requires the conserved "WKI" motif within the TRAF domain. We also investigated the role of NIK in JNK activation by TNF. Whereas overexpression of NIK potently induced NF-kappaB activation, it failed to stimulate JNK activation. A kinase-inactive mutant of NIK was a dominant negative inhibitor of NF-kappaB activation but did not suppress TNF- or TRAF2-induced JNK activation. Thus, TRAF2 is the bifurcation point of two kinase cascades leading to activation of NF-kappaB and JNK, respectively.

Calcium-Calmodulin-Dependent Protein Kinases↗

Identification and characterization of an IkappaB kinase.

Activation of the transcription factor NF-kappaB by tumor necrosis factor (TNF) and interleukin-1 (IL-1) requires the NF-kappaB-inducing kinase (NIK). In a yeast two-hybrid screen for NIK-interacting proteins, we have identified a protein kinase previously known as CHUK. Overexpression of CHUK activates a NF-kappaB-dependent reporter gene. A catalytically inactive mutant of CHUK is a dominant-negative inhibitor of TNF-, IL-1-, TRAF-, and NIK-induced NF-kappaB activation. CHUK associates with the NF-kappaB inhibitory protein, IkappaB-alpha, in mammalian cells. CHUK specifically phosphorylates IkappaB-alpha on both serine 32 and serine 36, modifications that are required for targeted degradation of IkappaB-alpha via the ubiquitin-proteasome pathway. This phosphorylation of IkappaB-alpha is greatly enhanced by NIK costimulation. Thus, CHUK is a NIK-activated IkappaB-alpha kinase that links TNF- and IL-1-induced kinase cascades to NF-kappaB activation.

Cloning, Molecular↗

Two-hybrid cloning of a gene encoding TNF receptor-associated protein 2, a protein that interacts with the intracellular domain of the type 1 TNF receptor: identity with subunit 2 of the 26S protease.

A protein that binds the intracellular domain of the type 1 TNFR (TNFR-1IC) has been identified by two-hybrid cloning. The 97-kDa TNFR-associated protein, TRAP2, shows sequence identity with internal amino acid sequences from subunit 2 of the 26S protease. TRAP2 antiserum recognizes subunit 2 of the 26S protease, which is consistent with the identity of these proteins. TRAP2 antiserum interacted with the 97-kDa protein in HeLa cell lysates and cytosol, the latter observation showing that TRAP2 resides in the same cellular compartment as TNFR-1IC. A fusion of glutathione-S-transferase and TNFR-1IC (GST-TNFR-1IC) precipitated TRAP2 from a HeLa cell lysate; conversely, GST-TRAP2 precipitated TNFR-1 from such a lysate. These observations show that the proteins interact in the cellular milieu. After in vitro transcription/translation and 35S labeling, TRAP2 was precipitated from a cellfree system by GST-TNFR-1IC, showing that TNFR-1IC and TRAP2 interact directly. TRAP2 was also precipitated from the cellfree translation system by a GST fusion containing the N-terminal half of TNFR-1IC, but not by a GST fusion containing the C-terminal half of TNFR-1IC that contains a "death domain" that plays an obligatory role in signaling cytotoxicity. The ability of deletion mutants of TNFR-1IC to interact with TRAP2 was tested using the two-hybrid system. This also showed that the amino acid sequences that mediate binding reside outside of the death domain in TNFR-1IC. The demonstration that a subunit of the 26S protease binds TNFR-1 may identify a novel TNF-signaling pathway.

Amino Acid Sequence↗

Expandable metallic stent placement in patients with benign esophageal strictures: results of long-term follow-up.

PURPOSE: To evaluate the long-term effectiveness of expandable esophageal metallic stents in benign esophageal strictures. MATERIALS AND METHODS: The authors performed long-term follow-up of 14 expandable metallic stents in 12 patients (aged 16-72 years) with benign esophageal strictures. All 12 patients had initially undergone placement of one stent; two patients received an additional stent because of recurrent dysphagia. RESULTS: No procedural complications occurred. Delayed complications occurred in all patients. New strictures formed in six stents (five patients), migration occurred in seven stents (six patients), and both migration and formation of new strictures occurred in one stent (one patient). New stricture formation caused recurrence of dysphagia and necessitated further treatment. Three of four stents that migrated within 2 months after placement but none of the four stents that migrated more than 2 months after placement caused recurrence of dysphagia. Six patients died of unrelated causes 6-20 months after stent placement. The remaining six patients are still alive 24-48 (mean, 35) months after stent placement. CONCLUSION: The long-term effectiveness of expandable metallic stents in benign esophageal strictures is not encouraging because of the high delayed-complication rate. That the patients with migration showed improvement of dysphagia, however, may warrant further investigation of temporary placement of a retrievable covered stent.

Adolescent↗

Benign and malignant esophageal strictures: treatment with a polyurethane-covered retrievable expandable metallic stent.

PURPOSE: To evaluate the clinical effectiveness of a polyurethane-covered, retrievable, self-expandable metallic stent and hook catheter in the treatment of esophageal strictures. MATERIALS AND METHODS: Stents were constructed of 0.4-mm stainless steel wire in a cylindric zig-zag configuration of six to nine bends. Four to eight stents were connected in tandem by dipping in a polyurethane solution. A nylon loop was hooked inside to each bend of the proximal portion of the stent and strung with a thread. Under fluoroscopic guidance, 22 stents were placed in 16 patients with a malignant stricture and five patients with a benign stricture. The stent was removed with a hook catheter 2 months after placement in patients with a benign stricture and when complications occurred in patients with a malignant stricture. All patients had dysphagia with ingestion of soft foods or liquids. RESULTS: Stent placement was technically successful and well tolerated in 20 patients. In one patient, the stent was misplaced but relocated successfully. After stent placement, all patients were able to ingest solid and/or soft foods without dysphagia. After stent removal, strictures showed improvement but recurred in two patients. CONCLUSION: Use of polyurethane-covered, retrievable expandable stents seems to be a feasible and effective method of treatment of benign and malignant esophageal strictures.

Adolescent↗

Renal angiomyolipoma: selective arterial embolization--effectiveness and changes in angiomyogenic components in long-term follow-up.

PURPOSE: To evaluate the efficacy of selective arterial embolization in symptomatic renal angiomyolipoma (AML) and the change in angiomyogenic components during long-term follow-up after embolization. MATERIALS AND METHODS: Fourteen adult patients with symptomatic AMLs underwent 16 selective arterial embolizations. The embolic materials used were absolute alcohol with (n = 5) or without (n = 3) iodized oil, Gianturco coils (n = 4), and polyvinyl alcohol foam powder with gelatin sponge (n = 2). Follow-up ultrasonography and computed tomography (CT) were performed in six and 14 patients, respectively. The effectiveness of selective arterial embolization was evaluated on the basis of the area of the angiomyogenic components in the AML on initial and follow-up images and clinical improvement. RESULTS: All patients showed devascularization of the tumor on the postembolization angiograms. In 13 patients, clinical symptoms disappeared. The follow-up period was 7-72 months (mean, 33 months). One patient underwent nephrectomy at 7 months after embolization because of a large cystic lesion found at 1 month. In long-term CT follow-up (> or =12 months) in 12 patients, nearly all angiomyogenic components disappeared, but fatty components partially shrank with liquefactive necrosis in tumors. CONCLUSION: Selective arterial embolization is an effective and safe treatment of AML. The angiomyomatous components crucial for the prevention of bleeding were very sensitive to the embolization.

Adult↗