Biomedical subjects

De-Chuan Chan

Publications and source records attributed to De-Chuan Chan.

21 records · Page 2Linked to original sources

PubMed2004

Primary malignant mesothelioma of the greater omentum: report of a case.

We report a rare case of primary malignant mesothelioma of the greater omentum. To our knowledge, only one other such case has been described in the English literature. The patient was a 61-year-old Taiwanese woman without any history of exposure to asbestos, who presented with lower back pain. Abdominal sonography and computed tomography showed a 12 x 9 x 9-cm(3) mass occupying the lower abdomen. Laparotomy revealed a tumor in the greater omentum, invading the posterior wall of the uterus, without diffuse mesenteric thickening or multiple small nodules in the peritoneum. We performed en bloc resection of the mass, which involved omentectomy, hysterectomy, and bilateral salpingo-oophorectomy. Microscopically, the tumor cells were arranged in a tubulopapillary pattern lined by a single layer of uniform, cuboidal cells. A pattern of sclerotic stroma with irregular glandular elements was also recognized. Immunohistochemically, the tumor cells showed strong positivity for calretinin. The final pathologic diagnosis was malignant mesothelioma. The patient did not receive chemotherapy or radiotherapy, and has remained in good health without any evidence of recurrence for almost 3 years since her operation.

Female↗

PubMed2004

Telomerase and c-myc expression in hepatocellular carcinomas.

BACKGROUND: Telomerase is activated in the majority of cancer tissues and immortalized cell lines. The hTERT (human telomerase reverse transcriptase-major component of telomerase) gene promoter has been cloned and contains many c-myc binding sites that mediate hTERT transcriptional activation. Thus far, the role of hTERT in tumorigenesis in hepatocellular carcinoma (HCC) has been little studied using RNA in situ hybridization. The relationship between c-myc and telomerase in human HCC tissue is undetermined. MATERIALS AND METHODS: The telomerase activity was assayed using TRAP in specimens from 23 HCC patients, hTERTmRNA was detected using in situ hybridization from 57 HCC patients. The immunohistochemistry for c-myc and DNA sequence for hTERT promoter, and tumour differentiation in relation to hTERT and c-myc expression were determined in 57 specimens. RESULT: hTERTmRNA was found in 47/57 (82.5%) HCC specimens using in situ hybridization. The hTERT expression paralleled telomerase activity, but hTERTmRNA regulation was not significantly associated with c-myc level ( P<0.954) The DNA sequence analysis of the hTERT promoter in specimens from 17 HCC revealed 15 cases of nucleotide transition (T-->C) over 5'-end of distal E-box and one case of nucleotide transversion (G-->C) over 5'-end of proximal E-box. Neither the hTERT expression (P< 0.890) nor c-myc level (P < 0.348) were related to HCC differentiation. CONCLUSIONS: The hTERT expression paralleled telomerase activity. The telomerase activity in HCC was not only regulated by c-myc. Another pathways might contribute to hTERT and telomerase activity regulation. The lack of telomerase activity in specimens from 17.4% of HCC cases might indicate an alternative pathway for maintaining telomere length. Furthermore, both the telomerase activity and c-myc had no significant role in HCC differentiation.

Carcinoma, Hepatocellular↗

PubMed2003

Effects of oral arginine and glutamine on radiation-induced injury in the rat.

BACKGROUND: Exposure of the abdominal region to ionizing radiation is associated with serious untoward symptoms of intestinal dysfunction and some reports indicate that nutrient supplements may reduce these adverse effects. This study was designed to investigate the possible beneficial effects of oral arginine or glutamine supplementation on the radiation-induced tissue injury. MATERIALS AND METHODS: Rats were given one of three feeding regimens: standard diet and water (control group), diet and water containing 2% arginine (arginine group), diet and water containing 2% glutamine (glutamine group) for 3 days prior to radiation. All rats were then subjected to a single does of 1100 cGy to the abdomen. Several serum biochemical parameters and the histologic alterations in different segments of gastrointestinal tract and liver were measured 4 days after irradiation. RESULTS: All the arginine-fed rats developed diarrhea on Day 4 postirradiation, compared to 71% incidence in control rats and 86% in glutamine-fed rats. Serum levels of aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) in the arginine group were markedly higher than those in other groups. On histological examination, radiation caused more serious damage to various segments of intestine in the arginine-fed rats compared to rats on other feeding regimens. CONCLUSION: These observations seriously question the beneficial effects of arginine and glutamine supplementations on radiation-induced tissue injury.

Administration, Oral↗