PubMed Health⌕ Search

Biomedical subjects

J H Wan

Publications and source records attributed to J H Wan.

14 recordsLinked to original sources
PubMed1992

Rapid method for detecting monoclonality in B cell lymphoma in lymph node aspirates using the polymerase chain reaction.

AIMS: To use the polymerase chain reaction to detect monoclonality at the immunoglobulin heavy chain gene locus in cells derived from lymph node aspirates. METHODS: A nested two-stage polymerase chain reaction (PCR) for the VDJ region of the immunoglobulin heavy chain gene was used to detect monoclonality. The total number of cells available for diagnosis by PCR in lymph node aspirates was between 10(4) and 10(5). RESULTS: A monoclonal band was detected in 21 of 25 malignant B-lymphomas. The other four specimens gave polyclonal bands. Specimens from reactive lymph nodes produced polyclonal bands in 14 cases, no product in two cases, and one specimen gave two monoclonal bands. Polyclonal bands were obtained for three Hodgkin's lymphoma samples and five metastatic carcinomas. Four metastatic carcinoma samples gave no amplification. CONCLUSIONS: Detection of monoclonality in a cell population is strongly suggestive of malignant disease. The simple PCR method presented here should complement conventional cytological and immunological methods for diagnosis of malignancy by lymph node aspirates.

Base Sequence↗
PubMed1991

Gene rearrangement in B- and T-lymphoproliferative disease detected by the polymerase chain reaction.

Gene rearrangement and monoclonality have been detected in normal cells and in lymphoproliferative disease by using the polymerase chain reaction and primers for the V and J regions of the Ig heavy chain gene or T-cell receptor gamma-chain gene. Using the Ig primers monoclonality was detected in 20 of 20 normal B-lymphocyte clones and in 39 of 52 cases of various types of B-lymphoproliferative disease, but not in 11 cases of T-lymphoproliferative disease. Using the T-cell receptor primers, monoclonality was detected in 186 of 192 normal T-lymphocyte clones, in 11 of 11 cases of T-lymphoproliferative disease, in 9 of 12 cases of B-acute lymphocytic leukemia, and in 1 of 21 cases of B-non-Hodgkin's lymphoma, but not in nine cases of B-chronic lymphocytic leukemia nor in 10 cases of myeloma. Monoclonality was detected in material obtained by lymph node aspiration in four of six additional cases of non-Hodgkin's lymphoma. It was not detected in 10 cases of acute myeloid leukemia nor in four cases of reactive lymphadenopathy. Detection of gene rearrangement by the polymerase chain reaction has a number of advantages over Southern blotting and is likely to become the initial diagnostic technique of choice to detect monoclonality.

Antibodies, Monoclonal↗
PubMed1991

Study on induction of differentiation of a human megakaryoblastic leukemia cell line (HIMeg) by 1,25-dihydroxyvitamin D3.

It is reported that 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), a physiological factor, has an inductive effect on the differentiation of a novel human megakaryoblastic leukemia cell line (HIMeg) in vitro. At the concentrations ranging from 10(-9) to 10(-6) mol/L, 1,25(OH)2D3 showed inhibition of proliferation on HIMeg cells which was demonstrated by count of survival cells and cloning efficiency. Meanwhile, using light/electron microscopy, stain of cytochemistry (including immunoenzymatic technique) and flow cytometry, we found that HIMeg cells could be further induced into more mature cells in megakaryocytic lineage confirmed by a series of evidence, including the changes of cell morphology/structure and cytochemistry, increased expression of differentiation antigens on the cell surface, and polyploidization. So, it is possible for 1,25(OH)2D3 to promote the differentiation of the cells in megakaryocytic lineage in vivo and to be used to treat acute megakaryoblastic leukemia and other diseases with malignant megakaryocytosis.

Calcitriol↗
PubMed1990

Monoclonality in B cell lymphoma detected in paraffin wax embedded sections using the polymerase chain reaction.

The polymerase chain reaction (PCR) was used to develop a simple technique for detecting monoclonality at the DNA level in B lymphocyte populations in formalin fixed, paraffin wax embedded material. Sections were dewaxed and dehydrated, and the DNA was extracted by boiling in water for 45 minutes. A semi-nested PCR was performed to amplify the V-D-J region of the immunoglobulin heavy chain gene. The product was electrophoresed and viewed under ultraviolet light after ethidium bromide staining. Specimens from 26 B cell lymphomas produced a monoclonal band in 24 cases and no amplification in two cases; monoclonality was specific for this disorder. Specimens from seven T cell lymphomas produced no amplification; specimens from nine reactive nodes produced a broad smear of polyclonal material; and specimens from 12 cases of carcinoma produced either no amplification or polyclonal material. As detection of monoclonality is strongly suggestive of neoplastic disease, this technique is likely to be of value in routine diagnosis, because of its speed, simplicity, and applicability to fixed, embedded material.

DNA, Neoplasm↗
PubMed1990

[Use of polymerase chain reaction (PCR) to detect monoclonality of B-lymphoproliferative disorders at DNA level].

A technique has been developed using PCR to detect monoclonality of B-lymphoproliferative disorders. DNA was extracted from the tissue, blood and paraffin embedded sections by biochemical means or boiling. Forty cases of B-non Hodgkin's lymphoma (NHL), 15 cases of T-NHL, 8 cases of chronic lymphocytic leukemia, 17 cases of reactive lymphadenopathy and 12 cases of various non-lymphatic tumor were examined. Monoclonality of B-lymphocytes was detected in 86-92% of cases with B-lymphoproliferative diseases, but none in T-NHL, reactive disorders and non-lymphatic tumors. This technique provides a new molecular biologic method to diagnose malignant B-lymphoproliferative disorders. It may be useful in Ig gene rearrangement study, differential diagnosis and retrospective investigation of lymphoproliferative disorders.

DNA, Neoplasm↗
PubMed1989

Establishment of a group of murine leukemic cell lines and investigation of their biological characteristics.

An in vitro-vivo technique for establishment of cell lines on murine leukemia has been developed. Using this method, suppressive T lymphoblastic leukemia L7811-85, L7212-85, non-T, non-B lymphocytic leukemia L1210-86, B lymphocytic leukemia P 388-86 and Friend erythroleukemia FLCL cell lines have been established. Incidence of leukemia with these cell lines was 100%. Along with the increase of generations of cell lines, cell growth accelerated, generation time shortened and cloning efficiencies rose. A following up electron microscopic observation on L7811-85 and L7212-85 showed that the virus particles were "A" particles in original cells. When they became cell lines in vitro, virus particles increased and transformed into typical "C" particles with budding. An inhibitory activity relevant to leukemic cells on proliferation of leukemic cells has been observed in the supernatant of L7811-85 medium and was regarded as an "autocrine".

Animals↗
PubMed1987

[Indirubin in the treatment of chronic myelocytic leukemia (CML)--estimation of labelling index of bone marrow cells by 3H-TdR].

Using 3H-TdR labelling radioautography in vitro, labelling index (LI) of the bone marrow cells from patients with CML was estimated before and after treatment by indirubin, and compared with myleran. The results showed that LI of the bone marrow cells was prone to decline after treatment by indirubin or myleran, and it was most marked on the myelocyte and polychromatophilic erythroblast. The LI reduction was less by indirubin than myleran. It suggests that the inhibition of indirubin on the bone marrow cells be weaker than that of myleran. However, long-term administration of indirubin would inhibit not only the granulocytic series but also the red cell series to a certain degree.

Adolescent↗
PubMed1985

Cell kinetics of the K-562 cell line in microculture.

The cell kinetic parameters of K-562 leukemia cells were studied using microwell cultures in which growth was initiated from a single cell. Total population growth was studied by direct enumeration, 3H-thymidine labelling, and flow cytometry. Clonogenic cell growth was studied by replating and 3H-thymidine suicide. In 7-day clones of K-562 cells, durations of the total cell cycle, G1, S, G2, and M phases were 20.8 h, 3.5 h, 12.9 h, 3.3 h, and 1.1 h, respectively; the growth fraction was 0.92 and the cell loss factor was 0.084. Study of colony-forming cells by replating indicated that clonogenic cells comprised 40% of total cells. 3H-Thymidine suicide showed that cell-cycle duration for these cells was 22.5 h and that S-phase duration was 11.7 h.

Cell Cycle↗
PubMed1985

Haemopoietic progenitor cells measured by limiting dilution in microwell culture.

Microwell culture assays, termed the "negative" well technique and the "positive" well technique have been used to measure the concentration of murine haemopoietic progenitor cells (HPC) by limiting dilution. Using morphologic examination and 3H-TdR uptake, the number of HPC of Balb/c mice per 10(5) bone marrow cells was 33 and 31 respectively. the linear relation between the number of harvested cells and input cells seen on the 4th and 7th days of culture reflected the growth of HPC in microwells. Besides measuring the concentration of HPC, this culture system may facilitate the analysis of effects on proliferation and differentiation of HPC of culture conditions, haemopoietic factors as well as cytotoxic agents.

Animals↗