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Biomedical subjects

W S Han

Publications and source records attributed to W S Han.

18 recordsLinked to original sources
PubMed2000

Up-Regulation and redistribution of Bax in ultraviolet B-irradiated melanocytes.

Ultraviolet B (UVB) radiation may activate or deteriorate cultured human epidermal melanocytes, depending on the doses and culture conditions. It is also reported that cultured human epidermal melanocytes derived from different pigmentary phenotypes showed different responses to UVB radiation. In this study, we examined whether apoptosis of melanocytes can be induced by physiologic doses of UVB irradiation using cultured human epidermal melanocytes derived from oriental males of skin types III and IV. Propidium iodide staining for DNA condensation and flow cytometric analyses demonstrated the apoptotic cell death of melanocytes following UVB irradiation (0-30 mJ/cm2). The levels of p53, Bax, and Bcl-2, determined by immunoblotting, revealed a dose-dependent increase in p53 and Bax, but the level of Bcl-2 remained unchanged. Confocal microscopic examination showed that Bax moved from a diffuse to a punctate distribution after UVB irradiation. However, there were no changes in the pattern of distribution of Bcl-2. These data suggest that the high constitutional level of Bcl-2 may protect melanocytes from UVB-induced injury, and that apoptotic death of melanocytes may be induced by the elevation and redistribution of Bax.

Apoptosis↗
PubMed2000

Comparative quantitative analysis of ultraviolet B-induced skin blood flow change using laser Doppler perfusion imaging technique.

Laser Doppler perfusion imaging (LDI), recently developed, can generate a color-coded image of tissue perfusion, making it possible to assess the spatial distribution of skin perfusion without touching the surface. Using this apparatus, we investigated ultraviolet B (UVB)-induced perfusion profile of the skin and compared the results with those obtained from laser Doppler flowmetry (LDF). Fifteen adult male Korean volunteers were irradiated with several doses of UVB ranging from 25 mJ/cm2 to 186 mJ/cm2. Twenty-four hours later, the erythema reaction was evaluated with LDF and LDI systems. There was a significant correlation between the logarithmic dose of UVB and erythema values. The curves consisted of two parts, an initial, flat phase and then a linear, steep one. Also, there was a good correlation between LDF and LDI. The LDI is as sensitive as conventional LDF, but has the many advantages of measuring blood flow over large areas without contact with the skin surface. This instrument will be useful in the measurement of skin blood flow in many areas of dermatological application.

Adult↗
PubMed2000

Pericarditis due to Tsutsugamushi disease.

Tsutsugamushi Disease is an acute febrile illness caused by Rickettsia tsutsugamushi, which enters into the human bloodstream through the bite of leptotrombidium. It is characterized by eschar, fever and cutaneous rash. Pericardial effusion in Tsutsugamushi Disease is not a common manifestation, although a high rate of effusion was reported in autopsy in those who had died of the disease. Here, we report a case of Tsutsugamushi pericarditis documented by indirect immunofluorescent test of pericardial fluid, and give a brief review of the literature.

Aged↗
PubMed2000

Identification of two novel frame shift mutations of the NF1 gene in Korean patients with neurofibromatosis type 1.

Neurofibromatos is type 1 (NF1) is one of the most common inherited disorders and is characterized by abnormalities in multiple tissues derived from the neural crest. The NF-1 gene has been cloned and mapped to human chromosome 17q11.2. The NF-1 gene has an open reading frame that predicts a protein consisting of 2,818 amino acids, known as neurofibromin. Here, we report two kinds of novel frame shift mutations of the NF1 gene from 2 out of 56 unrelated Korean NF1 patients. These mutations were detected using polymerase chain reaction and single strand conformational polymorphism analysis. Sequencing analysis revealed four base pair insertion at codon 1270 of exon 22, and a base pair deletion at codon 1398 of exon 24. These mutations resulted in premature termination of the mutant alleles and may encode truncated forms of neurofibromin.

Adult↗
PubMed1999

Elevated serum levels of transforming growth factor-beta1 in patients with colorectal carcinoma: its association with tumor progression and its significant decrease after curative surgical resection.

BACKGROUND: Transforming growth factor-beta1 (TGF-beta1) acts as a potent inhibitor of cell growth and tumor progression but loss of this negative regulation can contribute to tumor development. Some studies have reported an association between disease progression and TGF-beta1 expression in patients with colorectal carcinoma, but their results were not always consistent. METHODS: Serum levels of TGF-beta1 were measured using an enzyme-linked immunoadsorbent assay in 121 consecutive patients with colorectal carcinoma and compared with TGF-beta1 serum levels in 31 healthy volunteers. Serum levels of TGF-beta1 also were measured in 50 patients who underwent curative surgical resection (part of the 121 preoperative patients) to compare their levels with preoperative serum levels of TGF-beta1. RESULTS: Serum levels of TGF-beta1 in patients with colorectal carcinoma (45+/-15 ng/mL) (mean+/-the standard deviation) were significantly higher than those in the healthy control group (32+/-4 ng/mL) (P = 0.001). Serum levels of TGF-beta1 increased with increasing tumor stage (P < 0.01). Serum levels of TGF-beta1 were correlated significantly with depth of tumor invasion, lymph node metastasis, distant metastasis, and serum levels of carcinoembryonic antigen (CEA). Serum levels of TGF-beta1 tended to increase with increasing CEA (correlation coefficient = 0.21; P < 0.05). The mean serum level of TGF-beta1 in patients with colorectal carcinoma before surgery (45+/-14 ng/mL) (n = 50) significantly decreased to 34+/-7 ng/mL, which was within the normal range (32+/-4 ng/mL), after curative surgical resection of the tumor (P = 0.0000). Serum levels of TGF-beta1 after tumor resection decreased more significantly in patients with higher preoperative levels of TGF-beta1 (from 53+/-12 ng/mL to 36+/-6 ng/mL) (n = 30). CONCLUSIONS: The results of the current study suggest that serum levels of TGF-beta1 in colorectal carcinoma patients may be associated with disease progression and may be used as a biomarker in the management of colorectal carcinoma patients. The authors believe further studies with a large number of patients for a longer follow-up period are necessary to conclude whether serum levels of TGF-beta1 carry significant clinical relevance.

Aged↗
PubMed1999

Detection of transforming growth factor-alpha in the serum of gastric carcinoma patients.

Transforming growth factor-alpha (TGF-alpha) is a ligand for epidermal growth factor receptor (EGFR) and it is overexpressed in various malignancies including lung, esophageal, colorectal, ovarian and gastric carcinomas. In patients with gastric carcinoma, its overexpression may be associated with advanced stage or poor prognosis. We have recently demonstrated that the mean serum level for EGFR in gastric carcinoma patients was significantly elevated compared with that of healthy controls. Using the enzyme-linked immunosorbent assay, the levels of TGF-alpha were determined in serum from 40 patients with gastric carcinoma (5 patients with stage I, 2 stage II, 4 stage III, and 29 stage IV patients) and 33 healthy controls. The mean serum level for TGF-alpha in the gastric carcinoma patients was significantly elevated as compared with that of healthy controls (104 +/- 235 vs. 22 +/- 16 pg/ml; p = 0.03). Eleven patients with gastric carcinoma (27.5%) showed elevated serum TGF-alpha levels above the cutoff value of 54 pg/ml (defined as 2 standard deviations above the mean of the control group). No significant association was noted between the positivity of TGF-alpha and clinicopathologic characteristics including gender, age and stage. However, poorly differentiated adenocarcinoma showed a higher positivity of serum TGF-alpha (43.8%) compared with other histologic types, which was marginally significant (p = 0.06). These results suggest that serum TGF-alpha could be useful as a tumor marker of gastric carcinoma for predicting prognosis and follow-up after surgery in patients whose initial serum TGF-alpha levels are elevated.

Adult↗
PubMed1998

Increased serum levels of transforming growth factor-alpha in patients with colorectal cancer.

PURPOSE: This study was conducted to investigate the serum levels of transforming growth factor-alpha in patients with colorectal cancer and to investigate the clinical significance of these levels in association with tumor stage and histologic differentiation. Also, serum levels of transforming growth factor-alpha were measured after curative surgical resection. METHODS: Serum levels of transforming growth factor-alpha were measured in 42 consecutive patients with colorectal cancer before surgery, in 21 patients after surgical resection (part of the 42 preoperative patients), and in 20 healthy volunteers. We used TGF-alpha Assay. RESULTS: Serum levels of transforming growth factor-alpha in patients with colorectal cancer were significantly higher than in the healthy control group (P = 0.001). Significant elevations in serum levels of transforming growth factor-alpha were found in 50 percent (21/42) of patients with colorectal cancer when the mean + 2 standard deviations (80.4 pg/ml) of the control group were used as the upper limit of the normal range. Serum levels of transforming growth factor-alpha tended to decrease with increasing tumor size (n = 31; r = -0.52; P = 0.002). Serum levels of transforming growth factor-alpha before surgery (89.7 +/- 44.4 pg/ml; n = 21) significantly decreased to 60.3 +/- 19.8 pg/ml after surgical resections of tumors (P = 0.017). Serum levels of transforming growth factor-alpha completely decreased to the same serum levels of the control group after surgical resections in all patients who had serum levels of transforming growth factor-alpha greater than mean + 2 standard deviations (80.4 pg/ml) of the control group preoperatively (n = 11; P = 0.002). CONCLUSIONS: Levels of preoperative transforming growth factor-alpha in patients with colorectal cancer appeared to be higher than levels measured in control subjects. Serum levels of transforming growth factor-alpha before surgery significantly decreased after surgical resections of tumors. Additional studies are warranted to determine if serum levels of transforming growth factor-alpha may be useful as a potential biomarker in the management of patients with colorectal cancer.

Adenocarcinoma↗
PubMed1998

Increased serum levels of mutant p53 proteins in patients with colorectal cancer.

We have examined the serum levels of the mutant p53 protein in patients with colorectal cancer preoperatively (n=50), and in patients with adenomatous polyp (n=13). Mutant p53 protein in patients after curative surgical resection of colorectal cancer (n=26, part of the fifty preoperative patients) was also measured. Serum samples were stored frozen at -70 degrees C until the time of analysis. We used the p53 mutant ELISA (QIA03, CALBIOCHEM) system. Serum levels of the mutant p53 protein in patients with colorectal cancer (mean=0.97+/-0.14 ng/ml, ranged from 0.7 ng/ml to 1.37 ng/ml, n=50) were significantly greater than those in patients with adenomatous polyp (mean=0.73+/-0.06 ng/ml, ranged from 0.69 ng/ml to 0.83 ng/ml) (p<0.001). There was a significant correlation between serum p53 levels and CA19-9 levels (p<0.01). Serum levels of the mutant p53 protein prior to surgery (mean=0.97+/-0.13 ng/ml, n=26) significantly decreased after surgical resection of tumor (mean=0.82+/-0.07 ng/ml) (p<0.001, paired t-test). These results suggest that mutant p53 protein might be used as a potential biomarker in the management of patients with colorectal cancer. Further study is warranted to establish its clinical significance.

Adenomatous Polyps↗
PubMed1997

Detection of epidermal growth factor receptor in the serum of gastric carcinoma patients.

BACKGROUND: Epidermal growth factor receptor (EGFR) is overexpressed in various malignancies including carcinoma of the breast, lung, esophagus, cervix, and stomach. In patients with gastric carcinoma, its overexpression may be associated with advanced stage and poor prognosis. METHODS: The levels of EGFR extracellular domain were determined in serum from 40 gastric carcinoma patients using enzyme-linked immunosorbent assay. Serum EGFR levels were measured in 5 Stage I, 2 Stage II, 6 Stage III, and 27 Stage IV patients, and 29 healthy controls. RESULTS: The mean serum level for EGFR in the gastric carcinoma patients was significantly elevated compared with that of healthy controls (681 +/- 226 fmol/mL vs. 440 +/- 46 fmol/mL; P < 0.0001). Thirty-one patients with gastric carcinoma (77.5%) showed elevated EGFR levels above a cutoff value of 532 fmol/mL (defined as 2 standard deviations above the mean of the controls). No significant association was noted between positivity of EGFR and gender, age, stage, and tumor differentiation. CONCLUSIONS: The authors believe that serum EGFR could be useful as a tumor marker of gastric carcinoma for diagnosis, prognosis, follow-up after surgery, and monitoring patient response to chemotherapy.

Adult↗
PubMed1997

Bilateral primary renal non-Hodgkin's lymphoma presenting with acute renal failure: successful treatment with systemic chemotherapy.

Primary renal non-Hodgkin's lymphoma (NHL) with acute renal failure is a very rare condition, which frequently occurs in bilateral renal involvement. We report a 26-year-old male with primary bilateral renal NHL presenting with acute renal failure. A CT scan of the abdomen showed markedly enlarged kidneys with multinodularity and para-aortic lymphadenopathy. A percutaneous renal biopsy demonstrated 'follicular center lymphoma, diffuse, small cell'. Thirteen cycles of systemic chemotherapy with cyclophosphamide-doxorubicin-vincristine-prednisolone (CHOP) and ifosfamide-methotrexate-etoposide-bleomycin (IMVP-Bleo) regimens were administered, which resulted in normalization of renal function with improvement of renal lymphoma. Since there was no further change of renal lesions after initial partial remission, a follow-up renal biopsy was performed 10 months after diagnosis, and no residual lymphoma was found.

Acute Kidney Injury↗
PubMed1996

Minimally differentiated acute myelogenous leukemia presented with multiple cervical lymphadenopathy.

Lymphadenopathy is a relatively uncommon finding of minimally differentiated acute myelogenous leukemia (AML-MO). We experienced a case of AML-MO in a 57-year-old man initially presented with multiple cervical lymphadenopathy. Bone marrow aspiration revealed myeloblasts, which were negative for myeloperoxidase, Sudan black B, Periodic acid-Schiff, non-specific esterase and double esterase reaction. In cell surface marker studies, CD13, CD14, CD33, CD34, CD45 and HLA-DR were present. CT scan of neck demonstrated multiple lymphadenopathy at both internal jugular chains, spinal accessory chains and submandibular area. He died about two weeks after diagnosis without specific treatment.

Fatal Outcome↗
PubMed1993

Leiomyoma of the bronchus treated by endoscopic resection.

Leiomyoma of the bronchus is a rare benign tumor. The type of surgical resection depends on the location of the tumor and secondary lung destruction, although most surgical treatment has required thoracotomy. Two Korean women who had pedunculated masses in the left main bronchus and in the right lower lobe bronchus were successfully treated by endoscopic resection. Their postoperative courses were uneventful. They are well 19 months and 10 months, respectively, after resection.

Adult↗
PubMed1992

[Effect of sodium artesunate on Plasmodium yoelii analysed by flow cytometry].

The effect of sodium artesunate on Plasmodium yoelii-infected mouse erythrocytes was analysed by flow cytometry. The results showed that malarial DNA content in experimental group was obviously decreased 2-5 hours after the drug was administered, fluorescence distribution of malarial DNA almost disappeared within 24 hours after the administration. Thus we deem that sodium artesunate can inhibit the DNA synthesis in P. yoelii.

Animals↗
PubMed1991

Renal cell carcinoma with acrometastasis: report of two cases and review of the literature.

Metastases to the small bones of the hands and feet are rare. Although acrometastasis is usually a late manifestation of disseminated disease, it may be the primary manifestation of an occult carcinoma. Clinically it may be confused with benign disease and be treated improperly. We report two cases of renal cell carcinoma metastatic to the distal phalanx of a finger in Case 1 and the proximal phalanx of a toe in Case 2. The lesion was discovered following trauma in Case 1. In Case 2 there was no history of trauma. These acrometastases were the first evidence of metastatic disease in these two patients who had undergone a nephrectomy for Stage II renal cell carcinoma 2 yr and 1 yr prior to the development of acrometastases, respectively. Additional visceral metastases developed over the following months in Case 1, and the patient expired 7 mo after the discovery of the acrometastasis. In Case 2, the acrometastasis was the only site of metastases, and the patient is alive and well without evidence of disease as of the latest follow-up in January 1990. Review of the literature, including our cases, revealed 22 cases of renal cell carcinoma metastatic to the bones of the hand, nine cases to the bones of the foot, and three cases to the bones of both hand and foot. The clinical characteristics, pathogenetic mechanisms, and treatment are reviewed.

Bone Neoplasms↗
PubMed1990

A case of idiopathic fibrosing pancreatitis.

We experienced a case of chronic fibrosing pancreatitis in an 18/12-year-old girl, which was idiopathic because there were no familial back ground, no cystic fibrosis of pancrease, no ductal anomalies and obstruction. The patient presented intermittent colicky abdominal pain and progressive obstructive jaundice, but T-tube drainage and removal of the lymph nodes around the common bile duct relieved her symptoms and disease process. This seems to be the first case reported in a Korean child. Idiopathic fibrosing pancreatitis should be considered in the differential diagnosis of abdominal pain with obstructive jaundice in children.

Abdominal Pain↗
PubMed1986

The operculum-plug area and membranous structure of the eggs of Trichuris trichiura.

Eggs of Trichuris trichiura were prepared for scanning electron microscopy (SEM) by the dimethylsulfoxide freeze-cracking method. The egg-shell and oocyte were examined by SEM. The egg has a chitinous shell which consists of more than 10 layers of dense lamellae. The shell is bordered by a limiting membrane. An operculum and a collar made of chitinous shell together form the opercular area. The operculum is an empty cavity. The chitinous fibers of the egg-shell in this area are diffuse and loose, with numerous micropores or spaces. The egg-shell in this area therefore appears to form a fine tubular network. The oocyte is an undifferentiated cell with a biconcave drum-like shape. The perivitelline space is conspicuous at both ends of the cell.

Animals↗