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Biomedical subjects

M H Kim

Publications and source records attributed to M H Kim.

At least 127 records · Page 7Linked to original sources
PubMed1999

Electrocardiographic predictors of successful ablation of tachycardia or bigeminy arising in the right ventricular outflow tract.

Among various electrocardiographic variables, the QRS duration in V2 was found to be the best discriminator of outcome in patients undergoing radiofrequency catheter ablation of the right ventricular outflow tract tachycardia and/or bigeminy. If the QRS duration is <160 ms in lead V2, the probability of successful ablation is lower than if the QRS duration is longer.

Adult↗
PubMed1999

Encapsulation of ethanol by spray drying technique: effects of sodium lauryl sulfate.

Microcapsules composed of ethanol, water and dextrin as a water-soluble polymer can be used to encapsulate poorly water-soluble drugs by spray drying technique. For the encapsulation of a high dose of poorly water-soluble drugs, large amounts of ethanol and consequently large quantities of dextrin are needed for the dissolution of drug and the encapsulation of ethanol, respectively. In order to increase the ethanol content with the decreased amount of dextrin, sodium lauryl sulfate (SLS) was employed in the preparation of microcapsules without drug by a spray drying method. Phase diagrams were prepared to determine the region of microcapsule formation with a three-component system of ethanol, dextrin and water. The homogeneous phase indicated in the phase diagram was used to prepare the alcoholic microcapsules since this phase was not separated rapidly and not too viscous to be spray-dried. Interestingly, SLS at concentrations below 2% remarkably increased both the ethanol content and the encapsulation efficiency of ethanol. The maximum ethanol content and encapsulation efficiency were observed with 0.5-1% of SLS (35.4 and 67.6%, respectively). Furthermore, the increase by SLS was more pronounced at the low dextrin/water ratios than at the high dextrin/water ratios. In particular, the ethanol content and the encapsulation efficiency with the dextrin/ethanol/water ratio of 0.4/1/1, which had relatively small amounts of dextrin, were about ten times higher in the presence of SLS than those without SLS. In conclusion, this study shows that small amounts of SLS can increase the ethanol content and the encapsulation efficiency of ethanol, and allow the reduction in the amount of dextrin required to encapsulate ethanol in the preparation of microcapsules. These findings suggest that the use of SLS may permit the effective encapsulation of high dose of water-insoluble drug into microcapsules.

Capsules↗
PubMed1999

Effects of beta-adrenergic blocking therapy on left ventricular diastolic relaxation properties in patients with dilated cardiomyopathy.

BACKGROUND: The hemodynamic mechanism for the improvement in left ventricle (LV) end-diastolic pressure in cardiomyopathy patients treated with beta-adrenergic blocking agents is controversial. We hypothesized that the salutary effect of this kind of therapy on LV end-diastolic pressure would be indicative of an improvement in late, passive diastolic relaxation properties. METHODS AND RESULTS: We studied 14 cardiomyopathy patients in normal sinus rhythm with no arteriographic evidence of coronary artery disease and an LV ejection fraction of </=40% by radionuclide angiography both before and after 6 months of metoprolol therapy with simultaneous micromanometry and biplane cineventriculography. Four comparable patients who were not treated with metoprolol were studied in a similar fashion and served as control subjects. In those receiving metoprolol, LV end-diastolic pressure decreased (P=0.001). The isovolumic relaxation index, tau(ln), shortened (P=0.03). In a similar fashion, the LV chamber stiffness constant, kappa, decreased (P=0.02), LV volume elastance improved (P=0.04), and the myocardial stiffness constant, kappa(e), decreased (P=0.02). A multiple regression analysis revealed that the decrease in LV end-diastolic pressure was indicative of significant improvements in tau(ln) and kappa(e) with the relationship: LV end-diastolic pressure=-4.73+0.27 tau(ln)+0.54 kappa(e) (r=0.81, P<0.0001). These LV diastolic relaxation properties did not change or worsened in the control cardiomyopathy patients. CONCLUSIONS: We conclude that the decrease in LV end-diastolic pressure in cardiomyopathy patients treated with metoprolol is an indicator of improvement in LV diastolic properties resulting from more complete myocardial relaxation.

Adrenergic beta-Antagonists↗
PubMed1999

Effect of electrode polarity on the energy required for transthoracic atrial defibrillation.

Two hundred patients with atrial fibrillation underwent transthoracic cardioversion using adhesive electrodes positioned at the apex and right infraclavicular area, and the apex electrode was randomly selected to serve as the cathode or anode. The mean defibrillation energy requirement with the cathodal configuration was significantly lower than with the anodal configuration.

Adolescent↗
PubMed1999

Development of dried liposomes containing beta-galactosidase for the digestion of lactose in milk.

The hydrolyzed-lactose milk for lactase-deficient subjects has a sweeter taste than whole milk, and some subjects dislike its taste. In order to cope with this shortcoming, we examined whether beta-galactosidase, which hydrolyzes lactose, added to the whole milk in the form of dried liposomes, would be able to digest lactose in milk following the lysis of liposomes in the presence of bile salts. Dried liposomes containing beta-galactosidase were prepared in the presence of trehalose by the dehydration-rehydration vesicle method to overcome the instability of the conventional liposome suspension. The stability of liposomal membranes was evaluated by measuring the activity of entrapped beta-galactosidase under various storage conditions. By treating liposomes with trehalose, which was found to prevent the fusion of liposomes and the leakage of entrapped drug, the entrapping efficiency increased up to fourfold. Over 95% of dried liposomes which had been stored at 17 degrees C for 60 days were reconstituted to liposomes upon rehydration process. From the stability study, dried liposomes were found to retain 87% of beta-galactosidase activity at 17 degrees C after 60 days and to be more stable than the multilamellar vesicle suspension prepared without trehalose. The lysis study showed that dried liposomes were hardly lyzed in the simulated gastric fluid with pepsin, but lyzed immediately more than 90% in 0.01 M deoxycholic acid. Lactose hydrolysis in the presence of deoxycholic acid after the addition of dried liposome-entrapped beta-galactosidase to whole milk was proportional to the quantity of entrapped beta-galactosidase and the amount of dried liposomes added. These results demonstrate that beta-galactosidase entrapped in liposome is stable and reconstituted mostly upon rehydration, and can digest lactose in milk after the efficient lysis of liposomes in the presence of bile salts. This study implies that beta-galactosidase entrapped in liposome may be applied to whole milk for lactase-deficient subjects.

Animals↗
PubMed1999

An 86 kDa diapause protein 1-like protein is a component of early-staged encapsulation-relating proteins in coleopteran insect, Tenebrio molitor larvae.

Recently, we reported two novel early-staged encapsulation-relating proteins (56 kDa and 48 kDa ERPs) isolated from the hemolymph of coleopteran insect, Tenebrio molitor larvae [Cho et al. (1999) Eur. J. Biochem. (in press)]. Here, a cDNA clone for another early-staged encapsulation-relating protein (86 kDa) was isolated. We found that the 86 kDa protein shows high homology with insect diapause protein 1. The 86 kDa protein was localized in the fat body and hemolymph, but not hemocyte lysate. A significant level of 86 kDa protein was detected in pre-pupae stage, but it decreased rapidly at late larvae and pupae, and no protein was found in embryo, early larvae and adult stages. This diapause protein 1-like protein is likely to be a component of early-staged encapsulation-relating proteins in the insect cellular defense reaction.

Amino Acid Sequence↗
PubMed1999

Molecular genetic analysis of the DiGeorge syndrome among Korean patients with congenital heart disease.

The DiGeorge syndrome (DGS) is a developmental defect of the third and fourth pharyngeal pouches, which is associated with congenital heart defects, hypoparathyroidism, cell-mediated immunodeficiency, velo-pharyngeal insufficiency and craniofacial dysmorphism. The aetiological factor in a great majority of DGS cases is monosomy for the chromosomal region 22q11. To analyze DGS at the molecular level, a new molecular probe (DGCR680) encompassing the ADU balanced translocation breakpoint was prepared. When 13 Korean patients with DGS-type congenital heart disease were analyzed with this probe, 9 turned out to have a deletion at this locus, and all of them except one exhibited a typical facial dysmorphism associated DGS. Though only 9 independent patients were detected to have a deletion at the locus using the commercial probe N25 (D22S75), which maps at about 160 kb from the ADU breakpoint to the telomeric end, results from fluorescence in situ hybridization revealed a deletion in all cases tested at this locus. Two patients who had a deletion at the locus D22S75 but not at DGCR680 did not exhibit any DGS-type facial abnormalities. This result implies that the 680 bp probe covering the ADU translocation breakpoint might be a candidate for a molecular marker that can distinguish a specific phenotype, such as facial features associated with the DiGeorge syndrome. This study also suggested that systematic approaches with several small DNA probes along the DGCR could help to dissect the complex phenotypes associated with the DiGeorge syndrome, such as cardiac defects, abnormal faces, thymic hypoplasia, cleft palate, and hypocalcemia, etc.

Adolescent↗
PubMed1999

Mutational analysis of aspartate residues in the transmembrane regions and cytoplasmic loops of rat vesicular acetylcholine transporter.

The vesicular acetylcholine transporter (VAChT) is responsible for the transport of the neurotransmitter acetylcholine (ACh) into synaptic vesicles using an electrochemical gradient to drive transport. Rat VAChT has a number of aspartate residues within its predicted transmembrane domains (TM) and cytoplasmic loops, which may play important structural or functional roles in acetylcholine transport. In order to identify functional charged residues, site-directed mutagenesis of rVAChT was undertaken. No effect on ACh transport was observed when any of the five aspartate residues in the cytoplasmic loop were converted to asparagine. Similarly, changing Asp-46 (D46N) in TM1 or Asp-255 (D255N) in TM6 had no effect on ACh transport or vesamicol binding. However, replacement of Asp-398 in TM10 with Asn completely eliminated both ACh transport and vesamicol binding. The conservative mutant D398E retained transport activity, but not vesamicol binding, suggesting this residue is critical for transport. Mutation of Asp-193 in TM4 did not affect ACh transport activity; however, vesamicol binding was dramatically reduced. With mutant D425N of TM11 transport activity for ACh was completely blocked, without an effect on vesamicol binding. Activity was not restored in the conservative mutant D425E, suggesting the side chain as well as the negative charge of Asp-425 is important for substrate binding. These mutants, as well as mutant D193N, clearly dissociated ACh binding and transport from vesamicol binding. These data suggest that Asp-398 in TM10 and Asp-425 in TM11 are important for ACh binding and transport, while Asp-193 and Asp-398 in TM4 and TM10, respectively, are involved in vesamicol binding.

Acetylcholine↗
PubMed1999

Association of oligohydramnios in women with preterm premature rupture of membranes with an inflammatory response in fetal, amniotic, and maternal compartments.

OBJECTIVE: This study was undertaken to examine whether oligohydramnios in women with preterm premature rupture of membranes is associated with evidence of fetal, amniotic, and maternal inflammatory responses. STUDY DESIGN: Amniotic fluid index was measured before the performance of amniocentesis in patients with preterm premature rupture of membranes. Fifty-nine patients who were delivered of preterm neonates (gestational age </=35 weeks) within 3 days of amniocentesis were included in this study. Amniotic fluid was cultured for aerobic and anaerobic bacteria and for genital mycoplasmas. The intensity of the inflammatory response was evaluated by the following: presence of clinical and histologic chorioamnionitis; amniotic fluid concentrations of interleukin 6, interleukin 1beta, and tumor necrosis factor alpha; amniotic fluid white blood cell count; and interleukin 6 concentrations in umbilical cord plasma at birth. Proinflammatory cytokines were measured with specific and sensitive immunoassays. RESULTS: Thirty-two percent (19/59) of patients had an amniotic fluid index </=5 cm. Patients with an amniotic fluid index </=5 cm had significantly higher rates of positive amniotic fluid culture results and clinical and histologic chorioamnionitis; higher median amniotic fluid concentrations of interleukin 6, interleukin 1beta, and tumor necrosis factor alpha; and higher median cord plasma concentrations of interleukin 6 than did those with an amniotic fluid index >5 cm (positive amniotic fluid culture result, 79% [15/19] vs 30% [12/40]; clinical chorioamnionitis, 37% [7/19] vs 5% [2/40]; histologic chorioamnionitis, 100% [17/17] vs 69% [24/35]; median amniotic fluid interleukin 6 concentration, 13.5 ng/mL; range, 0.2-142.2 ng/mL vs 3.0 ng/mL and 0.001-115.2 ng/mL; median amniotic fluid interleukin 1beta concentration, 348.0 pg/mL; range, 0.7->80, 000 pg/mL vs 36.6 pg/mL and 0-2075 pg/mL; median amniotic fluid tumor necrosis factor alpha concentration, 132.0 pg/mL; range, 0-1600 pg/mL vs 11.2 pg/mL and 0-1305 pg/mL; median cord plasma interleukin 6 concentration, 49.7 pg/mL; range, 4.4-7400 pg/mL vs 9. 1 pg/mL and 0-5211 pg/mL; P <.05 for each). There was no significant difference between the 2 groups of patients in the mean umbilical artery pH at birth. CONCLUSION: Oligohydramnios in women with preterm premature rupture of membranes is associated with an inflammatory response in the fetal, amniotic, and maternal compartments.

Amniotic Fluid↗
PubMed1999

Usefulness of cholangioscopy in patients with focal stricture of the intrahepatic duct unrelated to intrahepatic stones.

BACKGROUND: Intrahepatic duct strictures are usually caused by intrahepatic duct stones and cholangitis. However, focal strictures of the intrahepatic duct unrelated to intrahepatic stones often pose diagnostic problems. This study was undertaken to prospectively evaluate the usefulness of percutaneous transhepatic cholangioscopy in patients with focal intrahepatic duct stricture and no evidence of a stone. METHODS: Seventeen patients with focal strictures of the intrahepatic duct without any evidence of a stone were included. Percutaneous transhepatic cholangioscopic examination including procurement of biopsy specimens was performed after percutaneous transhepatic biliary drainage. RESULTS: A histopathologic diagnosis was obtained in all patients (9 adenocarcinomas, 1 squamous cell carcinoma, 2 hepatocellular carcinomas, 2 adenomas, and 3 benign strictures). Of the 9 patients with bile duct adenocarcinoma, 8 underwent surgery and a curative resection was possible in 7 patients (88%). Five patients (63%) had early-stage bile duct cancer in which cancer invasion was limited to the mucosa or fibromuscular layer and there was no evidence of lymph node metastasis. CONCLUSIONS: Percutaneous transhepatic cholangioscopy in patients with focal stricture of the intrahepatic duct unrelated to choledocholithiasis is useful for diagnosis including the detection of early bile duct cancer.

Adult↗
PubMed1999

Epidemiological study on Korean gallstone disease: a nationwide cooperative study.

To clarify the epidemiological characteristics of gallstone disease in Korea and to evaluate the chronological changes in gallstone disease, the authors performed this first prospective nationwide cooperative study. The subjects were 1263 gallstone patients who were admitted at 19 hospitals in Korea from February to July 1997. Questionnaires were recorded on 1263 patients and gallstones were harvested from 1133 patients. The proportion of patients with gallbladder (GB), common bile duct (CBD), and intrahepatic duct (IHD) stones among total gallstone patients was 64.0%, 21.9%, and 14.1%, respectively. GB stones were categorized as cholesterol (58.1%), black pigment (25.2%), and brown pigment (12.1%) stones. CBD stones were classified as brown pigment (76.1%), cholesterol (18.4%), and black pigment (3.5%) stones. IHD stones were classified as brown pigment (61.4%) and mixed (35.6%) stones. Intrahepatic mixed stones had mean cholesterol and bilirubin contents of 63.4 +/- 20.8% and 23.1 +/- 9.9%, respectively. In contrast, IHD brown pigment stones had mean cholesterol and bilirubin contents of 35.1 +/- 20.5% and 39.6 +/- 17.4%, respectively. Our study showed that the type and composition of gallstones in Korea was somewhat different compared with those in the West. This study also demonstrated that there have been chronological changes in the type and composition of gallstones when compared with previous domestic data. Another nationwide cooperative study may be needed to elucidate and confirm the changing pattern of gallstone disease.

Adolescent↗
PubMed1999

Endoscopic hemostasis in sphincterotomy-induced hemorrhage: its efficacy and safety.

BACKGROUND AND STUDY AIMS: Hemorrhage is induced in approximately 0.5-12% of endoscopic biliary sphincterotomy (ES) procedures. We prospectively investigated the risk factors for ES-induced hemorrhage and evaluated the safety as well as the effectiveness of endoscopic hemostasis. PATIENTS AND METHODS: The study included 1304 patients who underwent ES between July 1996 and June 1998. Epinephrine spray was used initially for hemostatic treatment. If bleeding persisted, an epinephrine injection was given consecutively. In patients with exposed vessels, epinephrine injection followed by alcohol injection was given. RESULTS: ES-induced hemorrhage occurred in 136 (10.4%) patients. The type of sphincterotome used (needle-knife sphincterotome, P=0.025) and the cutting speed (the so-called "zipper" cut, P = 0.049) were revealed as significant variables with regard to the occurrence of bleeding. Mild, moderate, and severe bleeding were noted in 108 (79.4%), 22 (16.2%), and six (4.4%) patients, respectively. Once bleeding occurred, patients with an associated ampullary lesion (impacted stone or cancer) or with coagulopathy were more likely to bleed profusely. Initial hemostasis was achieved in all patients. However, rebleeding occurred in eight patients who were initially classified as having moderate or severe bleeding. Finally, ES-induced hemorrhage was successfully controlled in all patients after 1-3 treatment sessions (mean 1.1 sessions). The difference in the incidence of complications between the groups treated or not treated by endoscopic hemostasis was not statistically significant. CONCLUSIONS: ES-induced hemorrhage occurred in 10% of the patients studied. The use of needle-knife sphincterotomy and the cutting speed were independent risk factors for the occurrence of bleeding. Once bleeding occurred, its severity was affected by an associated ampullary lesion (impacted stone or cancer) or coagulopathy. Endoscopic hemostasis with epinephrine and/or alcohol was effective and safe in ES-induced hemorrhage.

Biliary Tract Diseases↗
PubMed1999

Clinical and histopathological characteristics of basal cell carcinoma in Korean patients.

Seventy-eight Korean patients with basal cell carcinoma (BCC) between 1984 and 1998 were retrospectively examined at Ewha Womans University Tongdaemun Hospital, Seoul, Korea. We analyzed the annual incidence, age and sex distribution, site of the lesions, clinical appearance, including the proportion of clinically pigmented tumors, modalities of treatment, incidence of recurrence and metastasis of the tumors, the histopathological patterns, and whether solar elastosis, microscopic pigmentation, or adamantinoid feature were associated. The male-to-female ratio was 0.902, and the average age of the patients at first examination was 58.2 years. Eighty percent of the tumors occurred on the head and neck, most commonly on the nose (26.9%), followed by the cheek, eyelid, and upper lip. Ulcerated nodules were the most common clinical presentation. Clinically, 55% of the tumors were pigmented. Six tumors recurred; none metastasized. Surgical excision was the most common modality of treatment. The most frequent histopathological pattern was the solid type (60.3%), followed by the superficial (11.5%) and fibrosing (9.0%) types. The occurrence of the superficial type was significantly associated with truncal lesions (p < 0.001). Solar elastosis was present in 62.1% of the tumors on the head and neck, compared with 8.3% in those of the trunk and limbs (p < 0.001), indicating the significance of sun exposure in the pathogenesis of BCC on exposed areas. Microscopic pigmentation was seen in 69.2% of the tumors. The focal adamantinoid feature was found in 14.1%, which is much higher than the previously reported incidence.

Adolescent↗
PubMed1999

Target temperatures of 48 degrees C versus 60 degrees C during slow pathway ablation: a randomized comparison.

INTRODUCTION: The relationship between temperature at the electrode-tissue interface and the loss of AV and ventriculoatrial (VA) conduction is not established, and the optimal target temperature for the slow pathway approach to radiofrequency ablation of AV nodal reentrant tachycardia (AVNRT) is unknown. Therefore, the purpose of this study was to compare target temperatures of 48 degrees C and 60 degrees C during the slow pathway approach to ablation of AVNRT. METHODS AND RESULTS: The study included 138 patients undergoing ablation for AVNRT. Patients undergoing slow pathway ablation using closed-loop temperature monitoring were randomly assigned to a target temperature of either 48 degrees C or 60 degrees C. The primary success rates were 76% in the patients assigned to 48 degrees C and 100% in the patients assigned to 60 degrees C (P < 0.01). The ablation procedure duration (33 +/- 31 min vs 26 +/- 28 min; P = 0.2), fluoroscopic time (25 +/- 15 min vs 24 +/- 16 min; P = 0.5), and mean number of applications (9.3 +/- 6.5 vs 7.8 +/- 8.1; P = 0.3) were similar in patients assigned to 48 degrees and 60 degrees C, respectively. The mean temperature (46.1 degrees +/- 24.8 degrees C vs 48.7 +/- 3.2 degrees C; P < 0.01), the temperature associated with junctional ectopy (48.1 degrees +/- 2.0 degrees C vs 53.5 degrees +/- 3.5 degrees C, P < 0.0001), and the frequency of VA block during junctional ectopy (24.6% vs 37.2%; P < 0.0001) were less in the patients assigned to 48 degrees C compared to 60 degrees C. The frequency of transient or permanent AV block was similar in each group (2.8% vs 3.6%; P = 0.2). In the 60 degrees C group, only 12% of applications achieved an electrode temperature of 60 degrees C. During follow-up of 9.9 +/- 4.2 months, there was one recurrence of AVNRT in the 48 degrees C group and none in the 60 degrees C group. CONCLUSIONS: Compared to 48 degrees C, a target temperature of 60 degrees C during radiofrequency slow pathway ablation is associated with a higher primary success rate and a higher incidence of VA block during junctional ectopy induced by the radiofrequency energy. AV block is not more common with the higher target temperature, but only if VA conduction is aggressively monitored during applications of radiofrequency energy.

Adult↗
PubMed1999

A new strategy for the application of CA19-9 in the differentiation of pancreaticobiliary cancer: analysis using a receiver operating characteristic curve.

OBJECTIVE: Clinicians might be misled in interpreting an elevated CA19-9 when differentiating pancreaticobiliary cancer from benign clinical conditions such as acute cholangitis or cholestasis, because in these conditions, the concentration of CA19-9 may also be elevated. The aims of our study were to calculate new individual cutoff values for CA19-9 according to clinical situations using a receiver operating characteristic (ROC) curve and to define a new strategy for interpreting CA19-9 in pancreaticobiliary cancer. METHODS: One hundred sixty patients with pancreatic diseases (cancer 90, benign disease 70), 322 patients with biliary tract diseases (biliary cancer 152, benign disease 170), and 20,035 asymptomatic controls were enrolled in the present study. An ROC curve was described by plotting the sensitivity on the y-axis against 1-specificity on the x-axis for each of several cutoff values. RESULTS: The area under the ROC curve was significantly greater for pancreatic cancer than for biliary cancer (p < 0.05). For patients with pancreatic cancer, CA19-9 proved to be useful. At a cutoff value of 37 U/ml, sensitivity and specificity were 76.7% and 87.1%, respectively. For patients with biliary cancer, CA19-9 was not helpful. However, when patients with biliary disease were divided into two groups according to the presence of cholangitis or cholestasis, CA19-9 proved to be more useful for the group without cholangitis or cholestasis than for the group with cholangitis or cholestasis (p < 0.05). In the former group, the sensitivity and specificity of CA19-9 were 77.6% and 83%, respectively, at the cutoff value of 37 U/ml. For the latter group, the sensitivity and specificity of CA19-9 were 74% and 41.5% respectively, whereas the specificity reached 87% at 300 U/ml. CA19-9 in diagnosing pancreatic cancer was useful regardless of accompanying acute pancreatitis or cholestasis. The serum concentration of CA19-9 in asymptomatic individuals was 9.42 +/- 9.95 U/ml. Only 1 of 157 patients with a concentration of CA19-9 above 37 U/ml was found to have gallbladder cancer. The positive and negative predictive values were 0.65% and 0.78%, respectively. CONCLUSIONS: The use of CA19-9 for the differentiation of pancreaticobiliary cancer should be applied individually, depending on the clinical situation.

Biliary Tract Diseases↗