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Biomedical subjects

G C Tseng

Publications and source records attributed to G C Tseng.

7 recordsLinked to original sources
PubMed2006

MCM7 amplification and overexpression are associated with prostate cancer progression.

The genomic DNA profiles of prostate cancers with aggressive features were compared to the profiles of matched normal DNA to identify genes that are selectively amplified in the cancer cells. One of the identified genes, MCM7, which is a component of the DNA replication licensing complex, has been studied extensively both at the DNA and protein levels in human prostate tissues. Approximately half of the prostate cancer specimens studied showed MCM7 gene amplification, and 60% of the aggressive prostate cancer specimens had increased MCM7 protein expression. Amplification or overexpression of MCM7 was significantly associated with relapse, local invasion and a worse tumor grade. Constitutive expression of MCM7 in a human prostate cancer cell line, DU145, resulted in markedly increased DNA synthesis and cell proliferation compared to vector-only controls, and an increased cell invasion in vitro. Indeed, MCM7 overexpression produced primary tumors 12 times larger than vector-only controls and resulted in a rapid demise of mice bearing those tumors. These studies implicate MCM7, and the DNA replication licensing gene family, in prostate cancer progression, growth and invasion.

Animals↗
PubMed2001

Issues in cDNA microarray analysis: quality filtering, channel normalization, models of variations and assessment of gene effects.

We consider the problem of comparing the gene expression levels of cells grown under two different conditions using cDNA microarray data. We use a quality index, computed from duplicate spots on the same slide, to filter out outlying spots, poor quality genes and problematical slides. We also perform calibration experiments to show that normalization between fluorescent labels is needed and that the normalization is slide dependent and non-linear. A rank invariant method is suggested to select non-differentially expressed genes and to construct normalization curves in comparative experiments. After normalization the residuals from the calibration data are used to provide prior information on variance components in the analysis of comparative experiments. Based on a hierarchical model that incorporates several levels of variations, a method for assessing the significance of gene effects in comparative experiments is presented. The analysis is demonstrated via two groups of experiments with 125 and 4129 genes, respectively, in Escherichia coli grown in glucose and acetate.

Acetic Acid↗
PubMed1996

Endometrial stromal sarcoma of twenty cases.

BACKGROUND: Endometrial stromal sarcoma is a rare neoplasm. We reviewed twenty cases to study the characteristics of this disease. METHODS: Twenty cases of endometrial stromal sarcoma were treated at our hospital. The clinical stage, treatment and outcome were retrospectively analyzed. RESULTS: Endometrial stromal sarcoma comprised 4.3% of corpus cancers and 46.4% of uterine sarcomas at our hospital. Seven cases were stage I, one was stage II, ten were stage III, and two were stage IV at the time of diagnosis. Histopathologically, seventeen cases were classified as low-grade sarcoma and three were high-grade sarcoma. Seven patients had recurrence and five of them had already died of disease. Among these recurrent patients, one was stage II and six were stage III. All three patients with high-grade sarcoma and four with low-grade sarcoma had recurrence. CONCLUSIONS: We think mitotic count is an important prognostic factor in low-grade endometrial stromal sarcoma and high-grade endometrial stromal sarcoma has a poor prognosis even with post-operative adjuvant treatment.

Adjuvants, Pharmaceutic↗
PubMed1996

Scalene lymph node metastases with the negative pelvic nodes in invasive cervical carcinoma.

Cervical carcinoma spreads predominantly by lymphatic routes and lymph node metastases may occur even in early stages of disease. Metastases usually first appear in pelvic lymph nodes, then disseminate along the efferent lymphatic chain to the extrapelvic lymph nodes. Cases of positive lymph node metastases with negative pelvic nodes in invasive cervical carcinoma are extremely rare. We report a 50-year-old woman with bulky stage IIA cervical carcinoma who had scalene lymph node metastases in the absence of pelvic lymph node metastases after radical hysterectomy and postoperative pelvic irradiation. This rare "skipping" nodal metastasis was probably via posterior trunk lymphatic drainage of the bulky cervical carcinoma which mainly invaded the posterior vaginal cuff. Neoadjuvant or adjuvant chemotherapy is recommended to prolong survival of patients in such cases.

Carcinoma, Squamous Cell↗
PubMed1994

Congenital nephrotic syndrome with microcephaly: report of a case.

Congenital nephrotic syndrome is an uncommon disease with variable etiology, course and prognosis; its association with microcephaly is even more unusual. A case is reported here of congenital nephrotic syndrome because of focal glomerulosclerosis in a three-month-old female infant with microcephaly since birth. There were no known renal diseases nor hereditary disorders in her family. The serologic tests for syphilis, toxoplasmosis, rubella, and cytomegalovirus infections were negative. Magnetic resonance imaging of the brain showed diffuse atrophic change of the cerebral hemispheres and brain stem with a remarkable increase of extracerebral space. The infant died at the age of four months without any clinical cause other than congenital nephrotic syndrome. These findings, including congenital nephrotic syndrome and microcephaly accompanied by various other clinical symptoms, have been described as a clinical entity with an autosomal recessive mode of inheritance.

Atrophy↗