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Biomedical subjects

D S Han

Publications and source records attributed to D S Han.

At least 19 recordsLinked to original sources
PubMed2006

Association of obesity, serum glucose and lipids with the risk of advanced colorectal adenoma and cancer: a case-control study in Korea.

BACKGROUND: Previous studies on colorectal cancer risk suggest that obesity, serum lipids and glucose might be related to colorectal carcinogenesis. This case-control study was conducted to investigate the association between obesity, serum lipids and glucose, and the risk of advanced colorectal adenoma and cancer. METHODS: Patients with histologically confirmed colorectal cancers (n=105), same number of patients with advanced colorectal adenomas matched by age and sex, and the same number of controls matched by age and sex were selected in Hanyang University Guri Hospital between January 2002 and June 2004. RESULTS: Adenoma and cancer group showed significantly higher levels of mean body mass index and serum glucose. Cancer group also showed significantly lower mean serum lipids levels than controls. We used an unordered polytomous logistic model to calculate multivariate odds ratios for advanced adenoma and cancer relative to controls. Higher serum glucose level was more strongly associated with increased risk of cancer relative to controls (odds ratio, 3.0; 95% confidence interval, 0.9-9.8) than with increased risk of advanced adenoma (odds ratio, 2.1; 95% confidence interval, 0.9-5.4). Higher body mass index was strongly associated with increased risk of advanced adenoma (odds ratio, 10.8; 95% confidence interval, 4.6-25.3), but associated with attenuated risk of cancer (odds ratio, 2.3; 95% confidence interval, 0.9-5.8). Serum triglycerides and cholesterol levels were strongly associated with reduced risk of cancer (odds ratio, 0.3; 95% confidence interval, 0.1-0.8 and odds ratio, 0.2; 95% confidence interval, 0.1-0.6, respectively). CONCLUSIONS: Obesity and hyperglycaemia are positively related to advanced colorectal adenoma formation. Furthermore, hyperglycaemia plays an important role in progression to cancer. Findings on an inverse relationship between serum triglyceride and cholesterol levels and the risk of colorectal cancer may be the secondary results from metabolic or nutritional changes in advanced colorectal cancer patients and should be clarified in further studies.

Adenomatous Polyps↗
PubMed2006

New insight of amino acid-based dialysis solutions.

Malnutrition is a major complication of peritoneal dialysis (PD) and is associated with increased morbidity and mortality. Daily losses of proteins and amino acids (AAs) into dialysate contribute to this problem. Previous metabolic balance study demonstrated that treatment with 1.1% AA-based dialysis solution is safe and may improve protein malnutrition in continuous ambulatory peritoneal dialysis (CAPD) patients ingesting low protein intake. Other prospective studies also showed that AA solution can provide nutritional benefit for malnourished PD patients resulting in a significant improvement in some biochemical and/or anthropometric nutritional parameters. However, there are other studies showing no particular improvement in nutritional parameters after long-term use of AA solution. This may be related to the differences in the study design, sample size, methods used to assess nutritional status, and other factors such as dietary intake and comorbidities of study subjects. Published data will be reviewed to further emphasize the nutritional benefit of long-term use of AA solution in malnourished PD patients along with a brief discussion on the various reasons that may partly explain the different study results. We will also present the results of a longitudinal observational study evaluating changes in nutritional parameters following use of one exchange of 1.1% AA solution in malnourished Korean PD patients. A significant improvement of somatic protein status such as lean body mass (LBM) and hand grip strength was observed. No significant change in serum albumin level was noted. Patients with a positive estimated coefficient for LBM in the fitted regression model to the repeated observations over 1 year were classified as responders and patients with neutral or negative coefficient were considered as non-responders. Thirty-one out of 43 malnourished patients (72%) showed nutritional benefit based on the change of LBM. Hand grip strength and back lift strength were significantly higher in responders at baseline. Other baseline parameters did not differ between the two groups.

Amino Acids↗
PubMed2006

Diagnostic yield of advanced colorectal neoplasia at colonoscopy, according to indications: an investigation from the Korean Association for the Study of Intestinal Diseases (KASID).

BACKGROUND AND STUDY AIMS: The factors that more accurately predict the detection of colorectal cancers and adenomas at colonoscopy are different. We conducted a prospective multicenter study to evaluate which indications were most closely associated with advanced colorectal neoplasm (CRN), including colorectal cancer, in a group of patients undergoing colonoscopy. PATIENTS AND METHODS: The 17 468 patients were enrolled in this study between July 2003 and March 2004, from 11 tertiary medical centers in Korea. They were recruited according to 11 itemized colonoscopic indications. The term "advanced adenoma" refers here to tubular adenomas of diameter of 11 mm or more, or to tubulovillous, villous, or severely dysplastic adenomas, irrespective of their size. Cancer was defined as the invasion of malignant cells beyond the muscularis mucosa. Advanced CRN was defined as advanced adenoma or invasive cancer. RESULTS: Advanced CRN was found in 1227/17 307 patients (1176 advanced adenomas plus 51 carcinomas, 7.1 %). According to univariate and multivariate analysis, the factors associated with advanced CRN included age >60 years (odds ratio (OR) 2.1, 95 % confidence interval (CI) 1.8 - 2.4, P < 0.0001), male gender (OR 2.1, 95 %CI 1.7 - 2.7, P < 0.0001), referral for colonoscopy from primary care physician (OR 3.1, 95 %CI 2.5 - 3.7, P < 0.0001), and several other indications (OR 1.8, 95 %CI 1.5 - 2.3, P < 0.001). The yield of colonoscopy for advanced CRN was lower (2.2 %) than expected in patients with iron-deficiency anemia (OR 0.5, 95 %CI 0.2 - 0.9, P = 0.03). CONCLUSIONS: Age, gender, and referral for colonoscopy from primary care physician constituted important independent predictors of advanced CRN in patients undergoing colonoscopy.

Adenoma↗
PubMed2005

Huge gastric diospyrobezoars successfully treated by oral intake and endoscopic injection of Coca-Cola.

A diospyrobezoar is a type of phytobezoar that is considered to be harder than any other types of phytobezoars. Here, we describe a new treatment modality, which effectively and easily disrupted huge gastric diospyrobezoars. A 41-year-old man with a history of diabetes mellitus was admitted with lower abdominal pain and vomiting. Upper gastrointestinal endoscopy revealed three huge, round diospyrobezoars in the stomach. He was made to drink two cans of Coca-Cola every 6 h. At endoscopy the next day, the bezoars were partially dissolved and turned to be softened. We performed direct endoscopic injection of Coca-Cola into each bezoar. At repeated endoscopy the next day, the bezoars were completely dissolved.

Administration, Oral↗
PubMed2004

Omental torsion: CT features.

A 33-year-old male presented to the emergency department complaining of right upper quadrant pain and was initially diagnosed with acute cholecystitis. Abdominal computed tomography showed a whirling pattern of fatty streaks and vessels within the greater omentum, and surgery confirmed infarction of the omentum secondary to torsion. We report a case of surgically and pathologically proven omental torsion that demonstrated the typical whirling appearance on computed tomography.

Abdominal Pain↗
PubMed2001

Novel findings in inhibition of mast cell-dependent immediate-type cutaneous reactions by Gahmi-Shini-San.

This report describes an inhibitory effect of Gahmi-Shini-San (GSS) on mast cell-mediated immediate-type allergic reactions. GSS is an Oriental herbal medication, which has been successfully used in Korea for the treatment of allergic disorders, mainly skin anaphylactic diseases. GSS inhibited the ear swelling response induced by intradermal injection of compound 48/80 in a mouse model on a concentration-dependent basis. The mast cells in mouse ear tissue were stained by alcian blue/nuclear fast red. GSS significantly inhibited the compound 48/80-induced degranulation from mast cells in ear tissue. GSS dose-dependently inhibited the histamine release from the rat peritoneal mast cells by compound 48/80. We also studied the effect of GSS on mast cell-dependent passive cutaneous anaphylaxis activated by dinitrophenyl IgE antibody. GSS showed inhibition of passive cutaneous anaphylaxis following oral administration. These results indicated that GSS has inhibitory effect on mast cell-dependent immediate type cutaneous reactions.

Alcian Blue↗
PubMed2001

Detection of circulating tumor cells in patients with gastrointestinal tract cancer using RT-PCR and its clinical implications.

To investigate the relationship between the presence of circulating tumor cells in different stages of gastrointestinal tract cancer and the subsequent relapse or distant metastasis, circulating levels of CEA mRNA was serially examined at an interval of 10.6+/-4.5 or 13.7+/-3.0 months in gastric or colorectal cancer patients, respectively. CEA mRNA was measured by means of RT-PCR amplification as an indicator for micrometastatic malignant cells. Seven of twenty-nine respectable gastric cancer patients (24.1%) [EGC: 2/9 (22.2%), AGC IIIa: 1/5 (20.0%), AGC IIIb: 4/15 (26.6%)] were positive for CEA mRNA on the initial test and 10 of 29 patients (34.4%) [EGC: 2/ 9 (22.2%), AGC IIIa: 1/5 (20.0%), AGC IIIb: 7/15 (46.7%)] were positive on a follow-up test. Only in AGC IIIb, the positive rate for CEA mRNA increased about twice and 6 of 7 positive cases (85.7%) relapsed within 2.6+/-2.4 months after the follow-up test. In colorectal cancer, 4 of 19 patients (21.1%) [B2: 1/6 (16.7%), C2: 3/13 (23.0%)] were positive on the initial test and 10 of 19 patients (52.6%) [B2: 4/6 (66.7%), C2: 6/13 (46.2%)] were positive on a follow-up test showing an increase in positive rates during a follow-up, however, no significant correlation between CEA mRNA positivity and subsequent relapse was demonstrated. These results suggest that an early tumor cell dissemination may occur in gastrointestinal tract cancer without subsequent relapse, however, the serial regular examination of CEA mRNA level may contribute to predicting a subsequent relapse in AGC IIIb in gastric cancer.

Adult↗
PubMed2001

Live donor renal allograft in end-stage renal failure patients from immunoglobulin A nephropathy.

BACKGROUND: The purpose of this study was to attempt to resolve two important issues, i.e. to determine (1) whether the course of recurrent immunoglobulin A nephropathy (IgAN) is benign, and (2) whether it is advisable to use a related donor. METHODS: We evaluated the long-term outcome, in terms of recurrence and graft survival, after live related or unrelated donor renal transplantation, and assessed the validity of the use of related donors in 90 grafts in 89 IgAN patients. RESULTS: Ten-year graft survival for IgAN patients was 66%, compared with 84% for 107 reference recipients who had other kinds of glomerulonephritis (GN), and with 69% in 90 other recipients who had non-GN renal failure (P=0.27). In 43 grafts, 54 event graft biopsies were performed, documenting the presence of mesangial IgA deposits in 19 of those grafts. In eight grafts, lesions were accompanied by chronic rejection (CR). Ten-year cumulative recurrence was 44%. Ten grafts were lost: by CR (n=3) or acute rejection (n=1) in 24 recurrence-free recipients, by CR (n=2) or recurrence (n=2) in 19 recurrent patients, and by patient death (n=2) in 46 patients devoid of graft biopsy. We found no difference in 10-year graft survival between the recurrent and recurrence-free patients (63% vs. 74%, P=0.98), or the proportion of related donors (68% vs. 83%, P=0.25). The presence or matching of HLA B12, B35, or DR4 did not affect the recurrence. CONCLUSIONS: Recurrence increased to 44% with longer follow-up, but this did not limit the graft outcome. Recurrence was not affected by the kind of live donor. We conclude that live related or unrelated kidneys should be offered to IgAN patients.

Adult↗
PubMed2001

Neurons reduce glial responses to lipopolysaccharide (LPS) and prevent injury of microglial cells from over-activation by LPS.

The microenvironment of the CNS has been considered to tonically inhibit glial activities. It has been shown that glia become activated where neuronal death occurs in the aging brain. We have previously demonstrated that neurons tonically inhibit glial activities including their responses to the bacterial endotoxin lipopolysaccharide (LPS). It is not clear whether activation of glia, especially microglia in the aging brain, is the consequence of disinhibition due to neuronal death. This study was designed to determine if glia regain their responsiveness to LPS once the neurons have died in aged cultures. When cultured alone, glia from postnatal day one rat mesencephalons stimulated with LPS (0.1-1000 ng/mL) produced both nitric oxide (NO) and tumor necrosis factor alpha (TNFalpha), yielding a sigmoid and a bell-shaped curve, respectively. When neuron-containing cultures were prepared from embryonic day 14/15 mesencephalons, the shape of the dose-response curve for NO was monotonic and the bell-shaped curve for TNFalpha production was shifted to the right. After 1 month of culture under conditions where neurons die, the production curves for NO and TNFalpha in LPS-stimulated glia shifted back to the left compared to mixed neuron-glia cultures. Immunostaining of rat microglia for the marker CR3 (the receptor for complement component C3) demonstrated that high concentrations of LPS (1 microg/mL) reduced the number of microglia in mixed-glial cultures. In contrast, reduction of CR3 immunostaining was not observed in LPS-stimulated mixed neuron-glia cultures. Taken together, the results demonstrate that disinhibition of the glial response to LPS occurs after neurons die in aged cultures. Once neurons have died, the responsiveness of glia to LPS is restored. Neurons prevented injury to microglia by reducing their responsiveness to LPS. This study broadens our understanding of the ways in which the CNS microenvironment affects cerebral inflammation.

Animals↗
PubMed2001

Long-term outcome of kidney transplantation in adult recipients with focal segmental glomerulosclerosis.

Focal segmental glomerulosclerosis (FSGS) is an important cause of nephrotic syndrome and end-stage renal disease. FSGS recurrence after renal transplantation has a potentially detrimental course leading to the loss of renal function. In order to establish FSGS recurrence rates and evaluate the course of the disease on living-related-donor renal transplantation in ethnic Korean adults (> or = 18 years), we reviewed our experiences of 27 kidney transplantations with FSGS over the last 15 years. Of the 27 renal allografts, 13 were found to have recurrent FSGS by graft biopsy. In comparison with background data upon patients with and without recurrence of FSGS, the donor age of patients with recurrent FSGS was significantly higher than that of those without recurrence (median, 39 years vs 26, p < 0.05). In terms of, age at transplantation, length of dialysis period, and mode of dialysis no differences were found between recurrent and nonrecurrent cases. The graft survival rate of recipients from a kidney donor of age less than 40 years was significantly higher than that of recipients from a kidney donor of age more than 40 years, at 5 and 10 years, respectively (87% vs 33%, 41% vs 0%, p < 0.05). The association between clinical variables and recurrence was assessed by multiple logistic regression analysis, and donor age was found to be a risk factor of FSGS recurrence (p<0.05). Variables such as HLA-mismatch numbers and immunosuppression were not found to be associated. In conclusion, the recurrence rate of FSGS in adult recipients with FSGS was 48% and patients that received kidney from an older donor appear to be at higher risk of developing recurrence. The use of a renal graft from a younger donor is considered advisable for adult recipients with FSGS.

Adult↗
PubMed2001

An analysis of 4,514 cases of renal biopsy in Korea.

To evaluate the distribution and changing patterns of renal diseases in Korea, a total of 4,514 cases of renal biopsy collected over a 23-year period between 1973 and 1995 were reviewed. Of 4,200 cases excluding 314 unsatisfactory biopsies, adult cases comprised 59.5% and pediatric cases, 40.5%. The male to female ratio was 1.5:1 in adults and 2.2:1 in children. Glomerulonephritis (GN) comprised 80.0% of the total. The most common primary GN in adults was minimal change disease (MCD) (26.6%), followed by IgA nephropathy (IgAN) (22.1%), membranous GN (MGN) (11.8%), and membranoproliferative GN (MPGN) (5.9%). In children, the primary GN incidence rates were MCD (24.8%), IgAN (10.3%), poststreptococcal (including postinfectious) GN (PSGN) (8.6%), and focal segmental glomerulosclerosis (FSGS) (4.0%). The most common secondary GN in adults was lupus nephritis and in children Henoch-Schonlein purpura nephritis. The most common cause of nephrotic syndrome was MCD in both adults and children, followed by MGN and FSGS. The elderly, aged sixty years and older, comprised 2.7% of cases and recorded equal numbers of MCD and MGN. The proportion of the biopsies found to be seropositive for HBs antigen was 27.9%, and these showed either MGN or MPGN pattern. Repeat biopsy was performed in 168 patients, due to previous biopsy failure in 15.5%. When the primary GN cases were analyzed at 5-year intervals, the prevalence of PSGN, which was greater than 25% during the 1973-1982 period, decreased abruptly in children thereafter, whereas the prevalence of FSGS increased slowly since the 1988-1992 period in both adults and children. The decrease of PSGN and the increase of FSGS suggest a role for socioeconomic and environmental factors in Korea.

Adult↗
PubMed2001

Clinical outcome in continuous ambulatory peritoneal dialysis patients is not influenced by high peritoneal transport status.

OBJECTIVES: We undertook this study to examine the influence of demographics, peritoneal membrane transport characteristics, nutrition indices, dialysis adequacy, and comorbid diseases on patient survival on continuous ambulatory peritoneal dialysis (CAPD), and to identify whether high peritoneal membrane transport is an independent risk factor for mortality on CAPD. DESIGN: Our retrospective study was carried out in CAPD patients in a large tertiary care teaching hospital. METHODS: Until December 2000, we followed 212 patients who started CAPD between 1994 and 1997 and who underwent a peritoneal equilibration test (PET) within 3 months of CAPD initiation. RESULTS: By univariate analysis, comorbid diseases, old age, high peritoneal transport, and serum albumin predicted patient mortality. Independent predictors of mortality as determined by the Cox proportional hazard model included diabetes mellitus, cardiovascular disease, serum albumin, and old age. High peritoneal transport failed to independently influence mortality in our CAPD patients.

Adult↗
PubMed2001

[Differentiation and malignant suppression induced by mouse erythroid differentiation and denucleation factor on mouse erythroleukemia cells].

OBJECTIVE: To investigate the roles of mouse erythroid differentiation and denucleation factor (MEDDF), newly cloned in our laboratory, in erythroid terminal differentiation. METHODS: Mouse erythroleukemia cells (MEL) were transfected with eukaryotic expression plasmid pcDNA-MEDDF. The changes of cell growth rate, mitotic index and colony-forming rate in semi-solid medium were investigated. The expressions of c-myc and beta-globin genes were analysed by semi-quantitative RT-PCR. RESULTS: MEL cells transfected with pcDNA-MEDDF showed significant lower growth rate, mitotic index, and colony-forming rate in semisolid medium(P < 0.01). The percentage of benzidine-positive cells was 32.8% after transfection. The expression of beta-globin in cells transfected with pcDNA-MEDDF was 3.43 times higher than that of control (MEL transfected with blank vector, pcDNA3.1), and the expression of c-myc was decreased by 66.3%. CONCLUSIONS: MEDDF can induce differentiation of MEL cell, and suppress its malignancy likely.

Activins↗
PubMed2000

Synthesis and cytotoxic effects of deoxy-tomentellin.

Cannabigerol (1, CBG), methyl 4-[(2E)-3,7-dimethyl-2,6-octadienyl)oxy]-3-methoxybenzoate (2, DTM), 5-fluorouracil (3, FU) as a reference, and cannabidiol (4, CBD) were tested for their growth inhibitory effects against KB(ATCC NO, OCL 17) cell lines using two different assays, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazoliumbromide (MTT) assay and the sulforhod-amine B protein (SRB) assay. These compounds showed inhibitory activity in vitro in the micromolar range against KB cell lines. In general, the antitumor activities of these compounds (1, 2, 3 and 4) were dose-dependent over the micromolar concentration range of 1 to 100 M. The comparison of IC50 values of these compounds in tumor cell lines showed that their susceptibility to these compounds decreases in the following order: DTM > CBD > 5-FU > CBG by MTT assay and DTM = CBD > 5-FU > CBG by SRB assay. CBG 1, DTM 2, 5-FU 3, and CBD 4 were tested for their cytotoxic effects on NIH 3T3 fibroblasts using two different assays, the MTT assay and SRB assay. These compounds exhibited potent cytotoxic activities in vitro in the micromolar range against NIH 3T3 fibroblasts. In general, the cytotoxic activities of these compounds (1, 2, 3 and 4) were dose-dependent over the micromolar concentration range of 1 to 100 M. The comparison of CD50 values of these compounds in NIH 3T3 fibroblasts shows that their susceptibility to these compounds in decreases the following order(:) CBD > 5-FU > DTM > CBG by MTT assay, CBD > 5-FU > CBG > DTM by SRB assay. These results suggest that DTM 2 has the most growth-inhibitory activity against KB cell lines.

3T3 Cells↗
PubMed2000

Purification, characterization, and primary structure of a chitinase from Pseudomonas sp. YHS-A2.

A chitinase gene (chiA) from Pseudomonas sp. YHS-A2 was cloned into Escherichia coli using pUC19. The nucleotide sequence determination revealed a single open reading frame of chiA comprised of 1902 nucleotide base pairs and 633 deduced amino acids with a molecular weight of 67,452 Da. Amino acid sequence alignment showed that ChiA contains two putative chitin-binding domains and a single catalytic domain. Two proline-threonine repeat regions, which are linkers between catalytic and substrate-binding domains in some cellulases and xylanases, were also found. From E. coli, ChiA was purified 12.8-fold relative to the periplasmic fraction. The Michaelis constant and maximum initial velocity for p-nitrophenyl-N,N'-diacetylchitobiose were 1.06 mM and 44.4 micromol/h per mg protein, respectively. The purified ChiA binds not only to colloidal chitin but also to other substrates (avicel, chitosan, and xylan), but the binding affinity of avicel, chitosan, and xylan is around 10 times lower than that of colloidal chitin. The reaction of ChiA with colloidal chitin and chitooligosaccharides (trimer-hexamer) produced an end product of N,N'-diacetylchitobiose, indicating that ChiA is a chitobiosidase.

Amino Acid Sequence↗