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Biomedical subjects

H S Chi

Publications and source records attributed to H S Chi.

At least 19 recordsLinked to original sources
PubMed2001

Phylogenetic analysis of reverse transcriptase in antiretroviral drug-naive Korean HIV type 1 patients.

To study whether genotypic antiretroviral resistance testing (GART) is needed to guide initial antiretroviral therapy in Korea, we determined partial pol sequences in peripheral blood mononuclear cells (PBMCs) obtained from 29 antiretroviral drug-naive HIV-1 patients. Phylogenetic analysis revealed four subtypes: B (23 patients), D (1 patient), recombinant strain (2 patients), and "untyped" (3 patients). Eighteen (78.3%) of the 23 subtype B isolates formed a distinct monophyletic cluster. The average genetic distances of 23 subtype B compared with reference strain HXB2 were 2.7% (range, 1.5-4.6%). Only one patient harbored variant virus containing a V179D mutation causing resistance to efavirenz. These data derived from therapy-naive patients suggest that potential use of primary resistance testing to guide initial antiretroviral therapy should be considered in Korea. This is the first report on the molecular nature of HIV-1 RT in Korea.

Adolescent↗
PubMed2001

Correlation of hematopoietic progenitor cell count determined by the SE-automated hematology analyzer with CD34(+) cell count by flow cytometry in leukapheresis products.

The yield of stem cell collection after mobilization is crucial for autologous peripheral blood stem cell (PBSC) transplantation. Quantitative determinations of CD34(+) cells using flow cytometry or stem cell culture have been used, but these methods require much time, technical experience, and expensive reagents. The automated hematology analyzer (Sysmex SE-9000trade mark, TOA, Japan) equipped with the Immature Information (IMI) channel for immature myeloid cells can detect IMI(+) cells within 90 sec. Detection is made possible by the combination of a special reagent system and direct current/radiofrequency biosensors. We studied the relation of IMI(+) cells and variable cell counts with CD34(+) cell yield in autologous stem cell harvest. In a series of 32 patients (median age, 44 years; M:F = 11:21), 184 leukaphereses were performed after mobilization regimens with chemotherapy and G-CSF or G-CSF alone. Full blood cell counts were enumerated on peripheral blood (PB) samples taken prior to each leukapheresis. Mononuclear cell (MNC) and IMI(+) cell counts by automated hematology analyzer and flow cytometry based CD34(+) cell yield were measured on the harvested product. The relationship among PB white blood cells (WBC), PB monocytes, IMI(+) cells, MNC, and CD34(+) cell yield in a single leukapheresis was estimated by Pearson correlation analysis. PB WBC count showed no correlation with CD34(+) cell yield in a single leukapheresis (r = 0.02, P = 0.81). PB monocyte count showed a weak correlation (r = 0.21, P = 0.01) and MNC in harvest also showed a weak correlation (r = 0.36, P = 0.0001) with CD34(+) cell yield. In contrast, CD34(+) cell yield correlated well with IMI(+) cell count (r = 0.68, P = 0.0001), and data could be fitted by a linear regression equation, y = 0.330 + 0.974x. IMI(+) cell assay by the automated hematology analyzer correlated well with the CD34(+) cell yield in a mobilized autologous stem cell harvest. The IMI(+) cell count might be used as a simple and efficient indicator of blood stem cell mobilization and collection.

Adolescent↗
PubMed2001

Effects of fixed low-dose warfarin on hemostatic factors in continuous ambulatory peritoneal dialysis patients.

Increased coagulation factors found in dialysis patients may explain in part the high prevalence of thrombotic cardiovascular disease. Several studies showed low-dose warfarin is effective in decreasing coagulation factors and preventing thrombosis without increasing the risk of bleeding. To evaluate the effects of fixed low-dose warfarin therapy on thrombogenesis in continuous ambulatory peritoneal dialysis (CAPD) patients, 76 CAPD patients were assigned randomly to treatment and disease control groups. The treatment group received 2 mg of warfarin daily for 12 months. International normalized ratio (INR) of the prothrombin time and plasma levels of factor VII, D-dimer, von Willebrand factor (vWF), and plasminogen activator inhibitor-1 (PAI-1) were measured before and 3, 6, and 12 months after the start of medication. The same parameters were measured in 30 healthy volunteers at the beginning of the study and in the disease control group during the study period. Of 76 patients, 60 completed the study. Deaths from atherosclerotic cardiovascular disease (cerebral infarction or acute myocardial infarction) occurred in 1 patient in the treatment group (n = 29) and 3 in the disease control group (n = 31), which was not statistically significant. No major bleeding occurred during the study period. With administration of warfarin, there was a small increase in INR in the treatment group. CAPD patients at baseline had significantly higher plasma factor VII, D-dimer, vWF, and PAI-1 levels than normal controls. Warfarin therapy lowered plasma factor VII and D-dimer levels. No change was seen in vWF and PAI-1 levels. In the disease control group, these hemostatic factors showed no change during the study period. There was a negative correlation between serum albumin and INR in the treatment group during the study period. Fixed low-dose warfarin was effective in partially reversing the thrombogenic coagulation profile in CAPD patients without a big increase in the risk of bleeding.

Anticoagulants↗
PubMed2001

Treatment of acute cerebral infarction with arginine esterase: a controlled study with heparin.

BACKGROUND AND PURPOSE: [corrected] There is no treatment proven to be of definitive benefit for ischemic stroke. Arginine esterase, a natural product from a snake venom, has been shown to reduce the serum fibrinogen level in human beings and may be useful in the treatment of ischemic stroke. In the present study, we compared the therapeutic effect of arginine esterase with that of heparin. SUBJECTS AND METHODS: We studied 50 consecutive patients with acute ischemic stroke who were admitted to the Asan Medical Center. We randomly administered either arginine esterase 0.005 unit/kg x 2 times/day or heparin (activated partial thromboplastin time 2-3 times of baseline value) intravenously for 7 days. Antiplatelets were administered afterwards in both groups. Blood fibrinogen, fibrinogen degradation product (FDP) and D-dimer levels were measured at 0, 6, 12, 18 h and 1, 2, 3, 7 and 30 days after the onset of stroke. NIH stroke scale was measured daily by 2 neurologists while Barthel index and Rankin scale were assessed at 7 days and 1 month after the onset of stroke by a research nurse. All these investigators were blinded to the therapeutic regimen each patient received. RESULTS: There were no significant differences in the mean age, gender proportion, stroke subtypes and baseline neurological severity between the two groups. One patient in the arginine esterase group died in an acute stage due to massive herniation and 1 in the heparin group underwent surgery for herniation. One (arginine esterase group) died of massive gastrointestinal bleeding due to previously unrecognized stomach cancer. Otherwise, no significant clinical and laboratory side effects were observed in both groups. In the arginine-esterase treated group, D-dimer and FDP levels were significantly (p < 0.05) elevated, and fibrinogen level significantly (p < 0.05) decreased at 2-7 days after the onset of stroke compared to the heparin-treated group. However, there was no significant difference in the neurological improvement reflected by NIH stroke scale, Barthel index and Rankin scale. CONCLUSION: Arginine esterase seems to be safe and has significant fibrinolytic effects when administered in the patients with acute ischemic stroke. However, in this preliminary study, it was not superior to heparin in terms of the improvement of neurological deficits. Further studies with larger doses and a larger number of subjects are required.

Acute Disease↗
PubMed2001

Cyclophosphamide and antithymocyte globulin conditioning may be sufficient for Korean patients with early stage severe aplastic anemia transplanted with marrow from donors other than HLA-identical siblings.

We gave a regimen of cyclophosphamide and antithymocyte globulin (CY/ATG) to six patients with early stage severe aplastic anemia (SAA) transplanted with marrow from alternative donors. All patients engrafted and are alive with durable engraftment at a median follow-up of 406 days. The CY/ATG regimen may be sufficient in Korean patients with early stage SAA receiving marrow transplantation from alternative donors.

Adolescent↗
PubMed2001

Spontaneous remission of aplastic anemia: a retrospective analysis.

BACKGROUND AND OBJECTIVES: Although acquired aplastic anemia is usually a chronic disorder, a small proportion of patients with aplastic anemia was reported to recover spontaneously without specific therapy such as allogeneic bone marrow transplantation or immunosuppressive treatment. We attempted to determine the rate of spontaneous remission in the patients with AA. DESIGN AND METHODS: We reviewed the medical records of adult patients (n=136) who were diagnosed as aplastic anemia at the Asan Medical Center from 1990 to 2000. The hematologic criteria of spontaneous remission were defined according to the proposed remission criteria of the SAA Working Party of the EBMT. RESULTS: Eighteen (13%) of 136 patients satisfied the criteria for spontaneous remission at median 14 days (range, 4-332) from the diagnosis of aplastic anemia. In fifteen (83%) of 18 patients, spontaneous remission occurred within 50 days. Spontaneous remission was complete in fourteen patients (78%). Only two patients relapsed at 208 and 1,857 days after spontaneous remission, respectively. Multivariate logistic regression analysis showed that presence of infection at diagnosis (p = 0.017), drug as an etiology of aplastic anemia (p = 0.028), and serum albumin level less than 3.4 g/dL (p = 0.005) were independent predictive factors for spontaneous remission. INTERPRETATION AND CONCLUSIONS: Our study confirmed that a minority of patients with AA recovered spontaneously. Spontaneous remission was rapid and complete in most patients, and relapses were rarely observed. In most cases with spontaneous remission, aplastic anemia might be associated with external factors such as drug or infection.

Adult↗
PubMed2000

Prognostic value of hematopoietic chimerism in patients with acute leukemia after allogeneic bone marrow transplantation: a prospective study.

Hematopoietic chimerism as a predictive marker for the relapse of acute leukemia after allogeneic BMT was evaluated in a prospective study. Monthly assays of hematopoietic chimerism were performed from peripheral blood samples by PCR amplification of short tandem repeats or amelogenin loci. Between December 1997 and June 1999, 33 patients enrolled and 30 were evaluable (two early deaths, one lack of informative bands for chimerism evaluation). There were 14 male and 16 female patients (15 AML and 15 ALL) with a median age of 31 years (range 16-46). Mixed chimerism (MC) was observed at least once in 14 of 30 patients (47%). There was no significant difference between 14 patients who showed MC (MC group) and 16 patients who did not show MC (complete chimerism (CC) group) in terms of age, sex, disease status at BMT, donor type, and the number of bone marrow cells infused. There was no significant difference in the neutrophil and platelet engraftment rates between the two groups. After a median follow up of 10.9 months (range 4.3-22.4), five patients in the CC group and two patients in the MC group relapsed (P = 0.27). All five patients who relapsed in the CC group maintained CC up to 1 month prior to clinical relapse. Our study demonstrated that the patients who showed MC post BMT did not have higher risk of relapse of acute leukemia when compared to patients who did not show MC. Sensitive PCR-based assays for hematopoietic chimerism applied on a monthly basis after allogeneic BMT could not predict relapse of acute leukemia.

Adolescent↗
PubMed2000

Veno-occlusive disease of the liver after allogeneic bone marrow transplantation for severe aplastic anemia.

There are few reports about the occurrence of hepatic VOD after BMT for severe aplastic anemia (SAA). We prospectively studied 17 patients with SAA after allogeneic BMT for the occurrence and severity of VOD. Plasma levels of protein C, protein S, antithrombin III, vWF, t-PA and PAI-1 were determined before preparative chemotherapy, on the day of marrow infusion, and on days 7, 14 and 21. VOD occurred in seven patients (41.2%) at a median of day 1 (range, day -2 to 15). Five had mild, and two moderate VOD. Platelet transfusion requirements were higher in the patients with VOD. The plasma levels of natural anticoagulants such as protein C, free protein S and antithrombin III decreased significantly on day 0 from the baseline levels. Plasma levels of t-PA, PAI-1 and vWF increased significantly in the early post-transplant period compared to the baseline levels. The mean plasma levels of t-PA on day 7 (P = 0.016) and PAI-1 on days 0 and 7 (P = 0.016, 0.032) were higher in the patients with VOD. In summary, we observed hypercoagulability and a high incidence of VOD after allogeneic BMT for SAA. Levels of t-PA and PAI-1 were significantly higher in the patients with VOD after BMT.

Adolescent↗
PubMed2000

Ontogeny of natural killer cells and T cells by analysis of BCR-ABL rearrangement from patients with chronic myelogenous leukaemia.

Chronic myelogenous leukaemia (CML) is a haematological malignant disorder characterized by the Philadelphia chromosome (Ph) and BCR-ABL gene rearrangement. This abnormal fusion gene can be considered to serve as a marker for the transformed cell clone in CML and is found in all cells arising from the same malignant precursor cell. It has been detected in CML cells of the myeloid, monocytic, erythroid and B-lymphocytic lineages. However, it is still arguable as to whether T lymphocytes or natural killer (NK) cells carry this marker. Answering this question would clarify the ontogenic relationship between NK cells and T cells. We examined 12 CML patients and studied the expression of BCR-ABL rearrangement by fluorescence in situ hybridization (FISH) in both NK cells and T cells sorted by flow cytometry. The purity of T cells was 95.6-99.8% and that of NK cells was 95.3-99.3% after sorting. Neither NK cells nor T cells showed any positive BCR-ABL signal with the exception of one patient who recovered from a lymphoid blastic crisis. We speculate that T cells and NK cells originate from BCR-ABL-negative stem cells.

Adult↗
PubMed2000

Effects of hormonal replacement therapy on lipid and haemostatic factors in post-menopausal ESRD patients.

BACKGROUND: Hormone replacement therapy (HRT) has been known to have beneficial effects on various atherosclerotic parameters in the general population of post-menopausal women. To evaluate the effects of HRT on those factors in end-stage renal disease (ESRD) patients, we evaluated the changes of lipid profile, coagulation and fibrinolysis markers, and plasma homocysteine levels after treatment. METHODS: Sixty-five post-menopausal women on maintenance haemodialysis were randomly assigned to either an HRT group (n=33) or a control group (n=32). Median age (range) and duration of haemodialysis (range) were 57 years (40-73) and 42 months (6-150) in the HRT group and 61 years (44-78) and 54 months (8-174) in the control group respectively. Oral conjugated oestrogen (0.625 mg) combined with medroxyprogesterone acetate (2.5 mg) was given daily for 12 weeks to the HRT group. Total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), lipoprotein (a) (Lp(a)), fibrinogen, plasminogen activator type 1 antigen (PAI-1), tissue plasminogen antigen (t-PA), von Willebrand factor (vWF), and plasma total homocysteine (tHcy) were measured before and 12 weeks after the start of the study in both groups. RESULTS: There was no difference in baseline values between the control and HRT groups. At 12 weeks, HRT increased HDL-C by 12% (P:<0.01) and TG by 20% (P:<0. 01). HRT decreased LDL-C by 9% (P:<0.01), and Lp(a) by 36% (P:<0.01). PAI-1 and t-PA concentrations were also reduced by 21% (P:<0.01) and 9% (P:<0.05) respectively. The mean values of TC, fibrinogen, vWF, and tHcy levels did not change significantly after HRT. CONCLUSIONS: The above results suggest that HRT has favourable effects on atherosclerosis risk parameters in post-menopausal women with ESRD as in the general population of post-menopausal women.

Adult↗
PubMed2000

Tissue plasminogen activator and plasminogen activator inhibitor-1 in human choledochal bile.

Fibrinolytic properties have been detected in animal and human gallbladder (GB) bile. Plasminogen activator inhibitor-1 (PAI-1) has been reported in greater concentration in GB stone bile and may be a nucleating factor in the pathogenesis of GB stone formation. It is unknown whether or not human choledochal bile has similar properties, which could have a role in choledocholithiasis. The aims of this study were to determine the presence of fibrinolytic properties of human choledochal bile and to compare those properties among normal, acalculous, and calculous-infected choledochal bile. Tissue plasminogen activator (t-PA) and PAI-1 of choledochal bile were measured by enzyme linked immunosorbent assay in patients with cholangitis due to acalculous bile duct obstructions (n = 9), choledocholithiasis with cholangitis (n = 20), and normal bile (n = 7). The t-PA concentration of choledochal bile was no different among the three groups (acalculous-infected bile, median 4.61 ng/ml, and calculous-infected bile, 4.61 ng/ml, versus normal bile, 7.33 ng/ml). PAI-1 was detected in choledochal bile in significantly greater concentrations in patients with acalculous cholangitis due to bile duct obstructions and choledocholithiasis with cholangitis (acalculous-infected bile, median 0.36 ng/ml, and calculous-infected bile, 0.1 ng/ml, versus normal bile, 0.02 ng/ml, p < 0.05), but the bile concentration of PAI-1 was no different between the acalculous and calculous-infected choledochal bile. Human choledochal bile possesses t-PA and PAI-1. PAI-1 was present in greater concentrations in both acalculous and calculous-infected choledochal bile. Increased levels of PAI-1 may be an epiphenomenon of cholangitis rather than a factor in the pathogenesis of choledocholithiasis.

Aged↗
PubMed2000

Rupture of the rectosigmoid colon with evisceration of the small bowel through the anus.

Spontaneous rupture of the rectosigmoid colon and herniation of the small intestine through the rupture site and eventual evisceration through the anus is a very rare event. In the literature, only 42 cases have been reported. The majority of them occurred in patients with rectal prolapse and one case was reported in association with a third-degree uterine prolapse. We experienced an 81-year-old female patient with rectal prolapse and second-degree uterine prolapse complicated by spontaneous perforation of the rectosigmoid colon and anal evisceration of the small intestine. Segmental resection of the nonviable small intestine, primary repair of the ruptured rectosigmoid colon, and sigmoid loop colostomy were performed, and the patient recovered well. In our patient, both rectal and uterine prolapses cooperatively damaged the anterior wall of the rectosigmoid colon and resulted in perforation. So, rectal and uterine prolapses should be treated before the complication develops. In this patient, uterine prolapse should be treated because of the recurrence of this rare episode.

Aged↗
PubMed2000

A case of minute intraductal papillary mucinous tumor of the pancreas presenting with recurrent acute pancreatitis.

Intraductal papillary mucinous tumor (IPMT) of the pancreas, a lesion consisting of mucin-producing cells with neoplastic potential, is characterized by duct ectasia, mucin hypersecretion, often extensive papillary intraductal growth, varying degrees of cytologic atypia, and relatively indolent growth. The clinical presentation of IPMT of the pancreas is characterized by chronic or recurrent attacks of abdominal discomfort often in association with low level pancreatic enzyme elevations. Less commonly these lesions may be detected as asymptomatic radiographic abnormalities. Interestingly, a case of a minute IPMT (2 mm in height and 7 mm in length, adenoma) in the main pancreatic duct presenting with acute pancreatitis in a 55 year-old man has been reported in the Japanese literature. Recently, we also experienced a case of a minute IPMT in a branch pancreatic duct causing repeated bouts of acute pancreatitis in a 75 year-old man. A filling defect at the neck of the main pancreatic duct seen on an endoscopic retrograde pancreatogram performed after recovery of the second attack of acute pancreatitis led the patient to undergo an exploratory laparotomy. After a near-total pancreatectomy was carried out, a minute (3 x 7 mm) IPMT of borderline malignancy was discovered in a branch duct at the head portion near the pancreatic neck without any lesions in the main pancreatic duct. Surprisingly, despite the resective surgery the patient died of carcinomatosis 8.5 months after the operation. We herein report a case of a minute but aggressive IPMT of the pancreas with a review of the literature.

Acute Disease↗
PubMed1999

Effect of increasing serum albumin on plasma D-dimer, von Willebrand factor, and platelet aggregation in CAPD patients.

This study was performed to investigate the interrelation between blood albumin level and D-dimer (a marker of intravascular coagulation) and von Willebrand factor (vWF; a marker of endothelial injury) levels or platelet aggregation. Blood levels of albumin, D-dimer, vWF, and C-reactive protein (CRP) and the threshold aggregating concentration (TAC) of ristocetin were measured in 64 continuous ambulatory peritoneal dialysis (CAPD) patients and compared with 36 healthy controls. Twenty-two CAPD patients with albumin levels less than 3.0 g/dL were divided into experimental and disease-control groups. In the experimental group, levels were measured before and after repeated infusions of 20% albumin, 100 mL/d for 7 days. The same parameters were measured in the disease-control group that did not receive the albumin infusion. CAPD patients had higher D-dimer and vWF levels than the healthy controls. There were inverse correlations between albumin and D-dimer (r = -0.48; P < 0.001), vWF (r = -0.29; P < 0.05), or logCRP (r = -0.44; P < 0.001) in CAPD patients. There were positive correlations between logCRP and D-dimer (r = 0.38; P < 0.01) and between logCRP and vWF (r = 0.32; P = 0.01) in CAPD patients. No change was seen in D-dimer, vWF, and CRP levels in either group. The TAC of ristocetin in the 18 CAPD patients was not different from that in the 11 healthy controls (0.55 +/- 0.09 v 0.65 +/- 0.07 mg/mL). There was a correlation between albumin level and TAC in the CAPD patients (r = 0.59; P < 0.01). TAC increased from 0.50 +/- 0.09 to 0.62 +/- 0.13 mg/mL (123% +/- 17%; P < 0.05; n = 6) at the end of the repeated albumin infusions in the experimental group, whereas it did not change in the control group. CRP level did not change in either group. The results of this study indicate that hypoalbuminemia increases platelet aggregability. The observation that the albumin infusion was not associated with changes in D-dimer and vWF despite the inverse correlations suggests that these relationships may be secondary to other factors, such as inflammation.

Adult↗
PubMed1999

Primary CD56 + nasal-type T/natural killer-cell subcutaneous panniculitic lymphoma: presentation as haemophagocytic syndrome.

Natural killer (NK) cells are large granular lymphocytes that mediate cytotoxic reactions which are not restricted by the major histocompatibility complex. In recent years it has become apparent that a minor proportion of malignant lymphomas expresses an NK-cell phenotype defined by its reactivity with the CD56 antibody. Primary purely cutaneous CD56 + lymphomas have rarely been reported. They share a generally aggressive course and are highly associated with Epstein-Barr virus. We describe a patient with a primary cutaneous nasal-type T/NK-cell lymphoma that presented as a haemophagocytic syndrome and showed an aggressive clinical course.

Adult↗
PubMed1999

Myelodysplastic syndrome that progressed to acute myelomonocytic leukemia with eosinophilia showing peculiar chromosomal abnormality: a case report.

Myelodysplastic syndrome is a closely related group of acquired bone marrow disorders characterized by ineffective and dysplastic hematopoiesis. These clonal disorders frequently progress to acute leukemia. Acute myelomonocytic leukemia with eosinophilia is characterized by an increase in abnormal eosinophils in the bone marrow, relatively good clinical course and inv (16) chromosomal abnormality. We experienced one case of refractory anemia with excess blasts which progressed to refractory anemia with excess blasts in transformation and finally to acute myelomonocytic leukemia with eosinophilia showing peculiar chromosomal abnormalities of der (1;7).

Adult↗