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Biomedical subjects

Do Young Kim

Publications and source records attributed to Do Young Kim.

28 records · Page 2Linked to original sources

[A prospective study on the prevalence and clinical significance of autoantibodies in patients with suspected nonalcoholic fatty liver disease].

BACKGROUND/AIMS: Exclusion of liver disease from other causes such as autoimmune hepatitis is necessary for diagnosis of nonalcoholic fatty liver disease (NAFLD). However, there has been no study on the prevalence and significance of autoantibodies in the patients with clinically suspected NAFLD in Korea, where hepatitis B is endemic and autoimmune hepatitis is relatively uncommon. METHODS: We prospectively tested for anti-nuclear antibody (ANA), anti-smooth muscle antibody (ASMA), and anti-mitochondrial antibody (AMA) in 135 serially enrolled patients with suspected NAFLD. We compared the clinical characteristics and biochemical indices of the ANA-positive or ASMA-positive group with those of the autoantibody-negative group. RESULTS: Sixteen patients (11.8%) had serum autoantibodies; there was ANA in 8 patients (5.9%), ASMA in 7 (5.1%), and AMA in 2 (1.5%). Both ANA and AMA were positive in one patient. The ANA-positive or ASMA-positive group showed an older age (49.5+/-13.0 vs. 42.0+/-10.9 years, respectively, P=0.018) and higher levels of serum globulin (3.1+/-0.4 vs. 2.9+/-0.4 g/dL, respectively, P=0.037), compared with the autoantibody-negative group. Two cases with positive ANA or ASMA fulfilled the diagnostic criteria for probable autoimmune hepatitis and two cases with positive AMA were suspected as primary biliary cirrhosis. CONCLUSIONS: These findings suggest that autoantibodies could be found in some patients with suspected NAFLD in Korea, AMA-positivity or ASMA-positivity could be associated with old age and high serum globulin, and some of the autoantibody-positive cases could be diagnosed as autoimmune hepatitis or primary biliary cirrhosis. Further studies are necessary to clarify the clinical significance of autoantibody positivity in those patients.

Adult↗

[Efficacy of repeated hepatic arterial infusion chemotherapy in advanced hepatocellular carcinoma with portal vein tumor thrombosis].

BACKGROUND/AIMS: The aim of this study is to elucidate the efficacy of repeated hepatic arterial infusion chemotherapy (HAIC) and different chemotherapeutic regimens for treating patients having advanced hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT). METHODS: From Jan. 1999 and Dec. 2003, a total of 103 patients diagnosed as having HCC with PVTT, but without extrahepatic spreading, were enrolled in this study. They were stratified into two groups. Group I (67 patients) received intraarterial cisplatin (CDDP, 80 mg/m2 for 2 hours on Day 1), Group II (36 patients) received intraarterial CDDP (60 mg/m2 for 2 hours on Day 2) and 5-fluorouracil (5-FU, 500 mg/m2 for 5 hours on Day 1-3). They were scheduled to receive at least three consecutive courses of the HAIC at 1 month intervals. RESULTS: Among the 66 patients who completed the protocol, one (2.5%) and seven (17.5%) patients of group I, and one (3.8%) and four (15.4%) of group II, exhibited complete and partial responses, respectively. The median survival period of all the patients was 6 months. Group II showed a tendency to improve the median survival compared to group I (8.5 vs 5.0 months, respectively, P=0.45). The most common adverse reaction was nausea (58.2%). However, an elevation of the total bilirubin level was more frequent in Group I than in Group II (61.3% vs 20.7%, respectively, P<0.05). CONCLUSIONS: Repeated HAIC using CDDP achieved favorable results in a few patients with HCC with PVTT, and additional 5-FU may be useful.

Adult↗

[Clinical outcome of pulmonary resections in patients with pulmonary metastasis of hepatocellular carcinoma].

BACKGROUND/AIMS: Although the lung is the most common site of extrahepatic spread from hepatocellular carcinoma (HCC), the role of surgery for pulmonary metastasis remains unclear. The aim of this study was to evaluate the efficacy of pulmonary resection in patients with pulmonary metastasis from HCC. METHODS: Between July 2000 and July 2004, a total of 6 patients with pulmonary metastasis from HCC underwent curative pulmonary resections. The patients were divided into two groups (Surgery group and Non-surgery group) according to the primary treatment modality of HCC. Medical records, imaging studies, and pathologic reports of the surgical specimens were reviewed. RESULTS: Three patients in the surgery group underwent pulmonary resections for a solitary metastasis after hepatectomy for HCC, and they are all still alive. One of the 3 patients developed a tumor recurrence in the chest wall after pulmonary resection. The survival time after diagnosis of HCC were 79, 122, and 54 months, respectively. The survival time after pulmonary metastatectomy were 49, 39, and 20 months in the three patients. Another 3 patients in the non-surgery group, received a pulmonary metastatectomy; they had either a complete response HCC or partial radiologic response. These 3 patients developed recurrent disease in the liver. One of 3 patients died. The survival time after diagnosis of HCC were 153, 83, 12 months. The survival time after pulmonary metastatectomy were 51, 4, 2 months. CONCLUSIONS: The surgical resections of a solitary pulmonary metastasis from HCC in highly selected patients might be an effective treatment modalities for prolonged survival.

Adult↗

[Reappraisal of HBV genotypes and clinical significance in Koreans using MALDI-TOF mass spectrometry].

BACKGROUND/AIMS: Recent studies have shown that the genotype of hepatitis B virus (HBV) may correlate with the disease natural history and treatment outcome. However, several of these studies used low sensitivity assays in a small number of patients, and this has precluded an accurate evaluation of Korean HBV genotypes. We analyzed Korean HBV genotypes in a large population by employing a new technology, restriction fragment mass polymorphism (RFMP) using MALDI-TOF mass spectrometry, in a sensitive and specific manner. METHODS: Between February 1995 and December 2003, a total of 475 patients with chronic HBV infection were enrolled. The assay is based on the mass measurement of oligonucleotides having genotypic variations of the S gene. Clinical features including the virologic status and disease progression were also evaluated. RESULTS: The median age of the total patients was 35.5 years. Out of 475 patients, there were 162 (34.1%) inactive carriers, 172 (36.2%) had chronic hepatitis, 77 (16.2%) had liver cirrhosis and 64 (13.5%) had hepatocellular carcinoma (HCC). There were 454 patients (95.6%) with genotype C, 4 patients (0.8%) with genotype A, 16 patients (3.4%) with the mixed A and C genotype [7 patients (1.4%) with A A], and 1 patient (0.2%) with B genotype. Comparing genotype A and C, genotype A patients were all inactive carriers without HCC, whereas genotype C patients included those with chronic hepatitis, liver cirrhosis and HCC. CONCLUSIONS: HBV genotype C is highly prevalent in Korea. Although it is a small percentage, genotype A also exists and it seems to take a more benign clinical course than genotype C. Further studies are necessitated to assess the relationship between HBV genotypes and the various aspects of the diseases' clinical course.

Adolescent↗

Colorectal flat neoplasia.

BACKGROUND AND AIMS: An attempt has been made to evaluate the clinicopathological characteristics of flat colorectal neoplastic lesions, and analyse the factors associated with the malignancy. PATIENTS AND METHODS: A total of 115 flat neoplastic lesions, > or = 5 mm in size, diagnosed in 87 patients by colonoscopy, were investigated. RESULTS: The rectum was the most common location. Almost half (49.6%) of the flat neoplasms were small (5-10 mm), 27.8% were 11-20 mm and the remainder (22.6%) larger than 20 mm. The surface was smooth in 55.7%, granular in 20.0% and nodular in 24.3%. Histologically, the flat lesions were tubular, tubulovillous and villous adenomas in 69.6%, 20.9% and 5.2%, respectively. Five lesions (4.3%) were composed of carcinomas without adenoma. High-grade dysplasia, intramucosal carcinoma and invasive carcinoma were diagnosed in 9.6%, 7.8% and 6.1% of all flat neoplasms, respectively. Univariate analysis demonstrated that the location, size, surface pattern and histologic type of the flat lesions were factors associated with malignancy. However, in multivariate analysis, the size of the flat lesions was the only significant risk factor for malignant transformation. CONCLUSIONS: Flat neoplastic lesions of the colorectum have a relatively high rate of malignancy, and size is the most important factor associated with malignancy.

Adenocarcinoma↗

Characterization of an extracellular medium-chain-length poly(3-hydroxyalkanoate) depolymerase from Streptomyces sp. KJ-72.

A bacterial strain capable of degrading medium-chain-length polyhydroxyalkanoates (MCL-PHAs) was isolated from a soil sample. This organism, which was identified as Streptomyces sp. KJ-72, secreted MCL-PHA depolymerase into the culture fluid only when it was cultivated on MCL-PHAs. The extracellular MCL-PHA depolymerase of the organism was purified to electrophoretic homogeneity by ion exchange column chromatography and gel filtration. The enzyme consisted of a monomeric subunit having a molecular mass of 27.1 kDa and isoelectric point of 4.7. The maximum activity was observed at pH 8.7 and 50 degrees C. The enzyme was sensitive to N-bromosuccinimide and acetic anhydride, indicating the presence of tryptophan and lysine residues in the catalytic domain. The enzyme was able to hydrolyze various chain-length p-nitrophenyl esters of fatty acids and polycaprolactone as well as various types of MCL-PHAs. However, lipase activity of the enzyme was not detected. The main hydrolysis product of poly(3-hydroxyheptanoate) was identified to be the dimer of 3-hydroxyheptanoate.

Carboxylic Ester Hydrolases↗

[Efficacy and safety of large volume paracentesis in cirrhotic patients with spontaneous bacterial peritonitis: a randomized prospective study].

BACKGROUND/AIMS: Large volume paracentesis (LVP) associated with plasma volume expansion is known to be an effective and safe therapy for tense or refractory ascites in cirrhosis. Spontaneous bacterial peritonitis (SBP) is one of the frequent infections in patients with cirrhosis. We conducted a study to assess the efficacy and safety of large volume paracentesis in cirrhotic patients with SBP. METHODS: We randomly assigned 40 patients with cirrhosis and SBP to either treatment with LVP (21 patients) or general management (19 patients). LVP was defined as drainage of ascitic fluid of more than 4 liters in a single tap or loss of shifting dullness after paracentesis. LVP was performed within 48 hours after the diagnosis of SBP in the LVP group. Cefotaxime was given daily in doses that varied according to the serum creatinine level in both groups. Albumin was given at a dose of 6-8 g per 1 liter of removed ascites in the LVP group. RESULTS: After seven days of treatments, the blood chemistry test, and WBC (PMN) counts and protein concentration in the ascitic fluid were not different between the two groups. Among them, the WBC (PMN) counts were decreased significantly in both groups and protein concentrations tended to increase. Durations of abdominal tenderness and pain were shorter in the LVP group but the differences were statistically not significant. Admission periods, resolution rates of SBP after seven days of treatment, complication rates and in-hospital mortality rates were not different between the two groups. CONCLUSIONS: The two treatment methods demonstrated almost the same effectiveness and safety. The symptoms were improved slightly faster in the LVP group. We concluded that large volume paracentesis is not an absolute contraindication and can be a tolerable and safe therapy in some selected cirrhotic patients with tense ascites and SBP.

Adult↗

Characterization of an extracellular medium-chain-length poly(3-hydroxyalkanoate) depolymerase from Pseudomonas alcaligenes LB19.

An extracellular medium-chain-length poly(3-hydroxyalkanoate) (MCL-PHA) depolymerase from an isolate, Pseudomonas alcaligenes LB19, was purified to electrophoretic homogeneity by hydrophobic interaction chromatography using Octyl-Sepharose CL-4B and gel permeation chromatography using Sephadex G-150. The molecular mass of the enzyme, which consisted of a single polypeptide chain, was approximately 27.6 kDa. The pI value of the enzyme was estimated to be 5.7, and its maximum activity was observed at pH 9.0 and 45 degreesC. The enzyme was significantly inactivated by EDTA and phenylmethylsulfonyl fluoride (PMSF) but insensitive to dithiothreitol. It was also markedly inhibited by 0.1% Tween 80 and 0.05% Triton X-100. The purified enzyme could hydrolyze various types of bacterial aliphatic and aromatic MCL-PHAs but not poly(3-hydroxybutyrate), polycaprolactone, and poly(L-lactide). Biodegradation rates of the aromatic MCL-PHAs were significantly lower than those of the aliphatic MCL-PHAs, regardless of the compositions and types of aromatic substituents. It was able to hydrolyze medium-chain-length p-nitrophenylalkanoates more efficiently than the shorter-chain forms. The main hydrolysis products of poly(3-hydroxynonanoate) were identified as monomer units. The results demonstrated in this study suggest that the MCL-PHA depolymerase from P. alcaligenes LB19 is a distinct enzyme, which are different from those of other MCL-PHA degrading bacteria in its quaternary structure, pI value, sensitivity to EDTA and PMSF, and hydrolysis products of MCL-PHA.

Carboxylic Ester Hydrolases↗

Poly(3-mercaptopropionate): a nonbiodegradable biopolymer?

Polythioesters (PTEs) represent a novel class of biopolymers, which basically can be synthesized with polyhydroxyalkanoate (PHA) biosynthesis systems. Albeit technical applications of PTEs have not been elucidated yet, biodegradability might be an important property of this new thermoplastic material. In this study, extensive approaches were employed to isolate microorganisms capable of degrading poly(3-mercaptopropionate), poly(3MP), as a model compound of PTEs. Screening of 74 different environmental samples using various enrichment techniques were applied, but neither bacteria nor fungi could be isolated hydrolyzing poly(3MP). Furthermore, microcosms such as soil, compost, or activated sludge were applied to search for poly(3MP) degrading microorganisms, considering microbial communities and/or nonculturable bacteria, and the poly(3MP) material was exposed for more than half a year. However, no poly(3MP) degrading organisms were found, indicating an unexpected persistence of this biologically produced polymer.

Bacteria↗