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T S Wan

Publications and source records attributed to T S Wan.

65 records · Page 4Linked to original sources
PubMed1997

t(High) frequency of telomeric associations in human ovarian surface epithelial cells transformed by human papilloma viral oncogenes.

Viral oncogenes are commonly used to transform and extend the in vitro life span of human epithelial cells. We have established 7 cell lines of human ovarian surface epithelial cells using human papilloma viral oncogenes (HPV-E6E7 ORFs). Cytogenetic analysis of the cell lines revealed a high frequency of telomeric associations ranging from 30% to 100% of the metaphases examined. The short arms of chromosomes 16, 19, 21, and 22 showed a higher rate of telomeric association. Telomeric association with other chromosomal ends appears to be random. Fusion of 2 chromosomes ends may contribute to the genomic instability of transformed cells and lead to further genetic alterations involved in malignant transformation such as gene amplication and loss of heterozygosity. This is the first report describing a high frequency of telomeric associations in human ovarian epithelial cells transformed by HPV oncogenes.

Cell Transformation, Neoplastic↗
PubMed1997

Robertsonian translocation as an acquired karyotypic abnormality in leukaemia.

Robertsonian translocations, although relatively common as a constitutional genetic aberration, are rarely encountered in leukaemia. We report a case of acute myeloid leukaemia which showed an acquired Robertsonian translocation in the form of der(14;21) by cytogenetic analysis of leukaemic cells. This was confirmed by the PHA-stimulated culture of peripheral blood lymphocytes. A review of the literature identifies only eight reported cases of acquired Robertsonian translocations in leukaemia. In the majority of cases the Robertsonian translocation occurs as a secondary change in a complex abnormal clone, whereas in two out of nine patients reported, including ours, it is found as a sole karyotypic abnormality.

Acute Disease↗
PubMed1995

Characterization of human ovarian surface epithelial cells immortalized by human papilloma viral oncogenes (HPV-E6E7 ORFs).

Primary human ovarian surface epithelial (HOSE) cells were immortalized by a retroviral vector (LXSN-16E6E7) expressing HPV-E6E7 open reading frames (ORF). Immortalizations of primary ovarian epithelial cells were achieved in three of three attempts. Detailed analysis was carried out in one line, HOSE 6-3, selected on the basis of its epithelial morphology. The immortalized line (HOSE 6-3) was nontumorigenic in nude mice when examined at subculture number 20. Cytogenetic analysis confirmed its human origin and detailed karyotypic analysis revealed a mixed karyotype made up of about 60% of diploid and 40% of near-tetraploid cells. Clonal chromosomal aberration was observed in a subpopulation of cells involving a ring chromosome number 9. Immunofluorescence and two-dimensional gel electrophoresis revealed the presence of vimentin and several species of cytokeratin (K7, K8, K18, K19). The profile of the cytoskeletal filaments of HOSE 6-3 cells is largely identical with that of normal ovarian epithelial cells before immortalization. The immortalized ovarian epithelial cells have a lower sensitivity to TGF-beta 1 inhibition compared to normal ovarian epithelial cells. The immortalized line, HOSE 6-3, has altered growth properties including a higher proliferation rate, plating efficiency, and saturation density. The establishment of a continuous line of human ovarian epithelial cells may provide an in vitro model for study of carcinogenesis in human ovarian cancers.

Cell Division↗
PubMed1994

Trisomy 14, deletion 20q and t(3;3) (q21;q26) in a case of myelodysplastic syndrome with myelofibrosis.

We describe a patient with trilineage myelodysplasia and hyperplastic megakaryopoiesis associated with significant myelofibrosis at diagnosis, who developed acute myeloid leukaemia two months afterwards. The clinical and pathological features were consistent with a myelodysplasia/myelofibrosis syndrome with leukemic transformation. Cytogenetic investigation showed trisomy 14, del(20q) and t(3;3) (q21;q26). These findings are of possible significance in the understanding of the association between myelodysplasia and myelofibrosis.

Chromosome Deletion↗
PubMed1993

Reproducible and high-speed separation of basic drugs by capillary zone electrophoresis.

The complete separation of a mixture of seventeen basic drugs of different classes was achieved with capillary zone electrophoresis in 11 min. The migration time reproducibility for individual components was between 0.5 and 1.7% relative standard deviation (R.S.D.). Peak detection was achieved by ultraviolet absorption, with peak-area reproducibility ranging from 1.5 to 6.3% R.S.D. The pH of the running buffer was critical in determining the separation of the mixture of basic drugs. The detection of most of these components in urine and plasma is also illustrated.

Electrophoresis↗
PubMed1993

Association between t(2;9)(p12;p23) and early B-precursor acute lymphoblastic leukemia.

We report the occurrence of t(2;9)(p12;p23) in a 20-month-old girl with early B-precursor acute lymphoblastic leukemia (ALL). This translocation has only been reported once before in an adult case of early B-precursor ALL with t(4;11)(q21;q23). We suggest that t(2;9)(p12;p23) may be associated with this particular phenotype of ALL.

Chromosomes, Human, Pair 2↗
PubMedDate not supplied

Effects of anticoagulants and incubation time on neutrophil nitroblue tetrazolium score.

We studied the effect of anticoagulants and incubation time on neutrophil nitroblue tetrazolium (NBT) scores. Heparin (10 IU/ml) and EDTA (1.5 mg/ml) were used, and the preparations were incubated for periods ranging from 20 to 180 min. Heparin, in contrast to EDTA, was found to be associated with cell destruction, cell aggregates and higher NBT scores; the effects were more profound with endotoxin stimulation. The duration of incubation significantly affects NBT scores in both the heparin- and EDTA-anticoagulated samples, and the effect is more marked with heparin. Cell destruction and cell clumping are both enhanced with incubation, again more so with heparin. It is concluded that when performing NBT tests, blood samples would best be anticoagulated with EDTA to ensure more consistent results.

Adult↗