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Biomedical subjects

T Han

Publications and source records attributed to T Han.

At least 127 records · Page 7Linked to original sources
PubMed1986

In-vitro infection of chronic lymphocytic leukemia cells by Epstein-Barr virus (EBV).

We sought to determine the potential of infecting lymphoid cells from patients with chronic leukemia (CLL) with Epstein-Barr virus (EBV) by testing for EBV receptors (EBVR) by flow cytometry, assessing for infectability of these cells by culturing with B95-8-derived virus, and staining for EB nuclear-associated antigens (EBNA) at various times post-infection. EBVR were present on 54-91% of lymphoid cells in seven cases of CLL and on 46% of prolymphocytic leukemia cells. Dynamic changes regarding EBNA positivity, morphology, and viability occurred post-infection with the virus. On day 2 only a few EBNA-positive lymphoblasts were observed. On days 11-21 positivity increased from 2 to 34% of cells. Simultaneously, the viable cell number declined to approximately 1/10th of original number. A significant proportion of the EBNA-positive cells corresponded to the original CLL cells. In 3 of 7 cases of CLL a Pan T-cell phenotype was demonstrated by Leu-1 monoclonal antibody testing. The infected cells did not react with two monoclonal antibodies, EBV-CS 1 and 4, which react with B-cell lymphoblastoid cell lines (B-LCL). Moreover, the B-LCL derived at 1-2 months post-infection of CLL cells did not express the Leu-1 antigen, but expressed EBV-CS 1 or 4 defined antigens. In the prolymphocytic leukemia, 64% of the cells showed EBNA positivity on day 7 and giant cells with huge round or multiple nuclei appeared which were EBNA-positive. CLL and prolymphocytic leukemia cells can be infected as demonstrated by EBNA-positivity. This infection does not lead to immediate transformation, but evokes lymphoblast and multinucleated giant cell production prior to the death of cells.

Aged↗
PubMed1986

Cytogenetic evidence for clonal evolution in B-cell chronic lymphocytic leukemia.

Sequential cytogenetic studies were performed in eight of ten patients with B-cell chronic lymphocytic leukemia presenting with trisomy 12 as the sole chromosomal abnormality. Follow-up studies of peripheral blood lymphocytes revealed that the karyotypes retained the sole abnormality of trisomy 12 in five cases, trisomy 12 converted to a normal karyotype during remission in one case, additional chromosome changes (-X,14q-) along with trisomy 12 appeared in one patient and multiple chromosome changes with or without trisomy 12 appeared in the remaining patient. The findings indicate that other chromosome changes in addition to trisomy 12 may develop as a result of clonal evolution or dedifferentiation, though the possibility that in two patients these changes may be related to chemotherapy and/or irradiation could not be ruled out entirely.

Aged↗
PubMed1986

Treatment of early--stages I and II--nodular, poorly differentiated lymphocytic lymphoma.

Twenty-nine patients with Stages I and II nodular, poorly differentiated lymphocytic lymphoma were treated with radiation therapy or radiation therapy plus chemotherapy. Twenty-two patients with Stage I received radiation to the involved field, the other seven with Stage II received total lymphoid radiation. Complete remission was achieved in all 29. There were no differences in remission duration or survival according to treatment modality. Five of 29 (17%) patients relapsed. No relapses were observed after 5 years. Ten patients died; one patient died of lymphoma, and nine others died in continuous complete remission of various other causes. Sixty-six percent of the patients were alive at 74-160 months (median 118 months). Involved field radiation with or without chemotherapy was well tolerated, producing acceptable toxicity. Substantially more toxicity was observed after total lymphoid irradiation and although cures were also achieved, less toxic treatment programs should be investigated. The low rate of relapse observed in early stages of this lymphoma in this and in other studies is suggestive that cures might be achieved in nearly one-half of the patients presenting in early stage.

Adult↗
PubMed1986

Bone formation within porous hydroxylapatite implants in human periodontal defects.

Tissue samples from three subjects who had periodontal defects treated with a porous hydroxylapatite implant were investigated using light microscopy and scanning electron microscopy. The 3-month specimen showed connective tissue infiltration through the pores and a narrow zone of bone formation present along the walls of the pores. At 4 months, continued evidence of bone deposition was present with osteocytes, osteoblasts and organization of collagen fibers apparent throughout the implant. The 6-month implant had further evidence of continued bone formation with lamellar bone being the major component within the pores.

Alveolar Process↗
PubMed1986

B cell growth factor-induced proliferation of hairy cell lymphocytes and inhibition by type I interferon in vitro.

Malignant B cells from hairy cell leukemia (HCL) patients are unable to proliferate when stimulated with standard B cell mitogens. Using chromatographically purified B cell growth factor (BCGF), HCL can be stimulated to proliferate as assessed by incorporation of tritiated thymidine [3HTdR] into DNA. Proliferation was found to be time dependent, with no detectable 3H-TdR incorporation in up to three days of culture, and significant stimulation evident at days 6 and 10. The presence of 10% BCGF in culture was an absolute requirement for HCL proliferation; however, this BCGF-induced DNA synthesis could be further augmented by the addition of anti-immunoglobulin heavy chain antibodies. BCGF-induced proliferation was abrogated in six of six patients by addition of 1,000 U/mL of recombinant alpha 2-interferon (IFN) at day 0, although 1,000 U/mL of recombinant gamma-IFN had no inhibitory effect in five of six patients studied. Specific cellular receptors for type I IFN were demonstrated in HCL by inhibition of binding of 125I-alpha 2-IFN by a 40-fold excess of unlabeled alpha 2 or beta IFN with no inhibition by unlabeled gamma-IFN. These data demonstrate that malignant HCL lymphoblasts express specific type I IFN receptors and that type I, but not type II IFN, can inhibit growth factor-induced DNA synthesis by hairy cells in vitro. They further suggest a direct antiproliferative mechanism of action for IFN in HCL and predict equivalent clinical activity by either alpha or beta, but not gamma IFN in this malignancy.

Adult↗
PubMed1986

Recurrent chromosome changes at 3p21 in Epstein-Barr virus-transformed cells derived from human prolymphocytic leukemia.

Cytogenetic studies of Epstein-Barr virus-transformed lymphoblastoid cells obtained from a patient with prolymphocytic leukemia revealed the cells to contain recurrent chromosome aberrations involving band 3p21. The in vivo leukemic cells from which the cell lines originated contained a der(3)t(3;17?)(p21;q11?) and a der(13)t(13;3)(q34;p21), as well as numerical (-Y, -8, and -17) and other structural [8p- and der(8)t(8;?)(q13?;?)] changes. The cells in established culture showed additional chromosome aberrations involving band 3p21 of the previously normal and abnormal chromosomes 3. After 200 days of culture, the cells contained a new translocation, i.e., t(3;14)(p21;q32). The cells showed further chromosomal breakage and reunion at band 3p21 at later passages. The affected chromosomal band (3p21) is close to one of the constitutive fragile sites, i.e., 3p14.2. Northern blot analysis of the messenger RNA of the cultured cells did not show an increased or altered expression of the c-raf-1 protooncogene (located at 3p25) when compared with the mRNA of Epstein-Barr virus-transformed lymphoblastoid cell lines from normal subjects with a normal karyotype. Also, the established cells did not show DNA rearrangements or RNA alterations of the c-myc gene.

Cell Line↗
PubMed1986

Primary chemotherapy for localized non-Hodgkin's lymphomas with diffuse histologic characteristics. Preliminary report of a prospective study.

Thirty-three patients with diffuse non-Hodgkin's lymphoma (stages I and II) received intermediate doses of oral methotrexate followed by leucovorin calcium every four weeks, on days 1 and 8, followed on day 15 by intravenous cyclophosphamide and vincristine sulfate. Prednisone was given for four weeks on alternate courses of treatment. A total of six such four-week courses was planned. Involved-field radiation (3000 or 3600 rad [30 or 36 Gy]) was given between three courses of chemotherapy to 18 patients who presented with tumors exceeding 7 cm in greatest diameter and who had responded to the initial chemotherapy. On completion of treatment, 27 patients (82%) were in complete remission; all the failures were in patients with large intra-abdominal masses. The presence of high lactate dehydrogenase levels, large tumor size, and age over 60 years had a suggestive negative correlation with the achievement of complete remission. The median follow-up was 26 months (range, ten to 59 months). At 48 months, the actuarial disease-free survival, remission duration, and overall survival were 53%, 72%, and 68% respectively. No deaths from toxic effects and no septic episodes were observed during treatment. The complete remission rate achieved with this program is comparable with those of other intensive programs of treatment reported previously.

Adult↗
PubMed1985

Clonal chromosome abnormalities in prison-acquired lymphoproliferative syndrome.

Lymph nodes from five male patients with prison-acquired lymphoproliferative syndrome (PALS), which seems to be a prodrome of acquired immune deficiency syndrome (AIDS), were examined cytogenetically. Two had clonal chromosome abnormalities, i.e., 11q- and -11, and another had multiple nonclonal chromosome changes, including t(2p-;3q+),6q-,+12,14q+. These chromosome changes are also common in malignant lymphoma and suggest that the patients with PALS may be predisposed to develop malignant lymphoma.

Adult↗
PubMed1985

Salvage treatment for patient with multiple myeloma refractory to alkylating agents.

Sixteen patients with multiple myeloma refractory to alkylating agents were treated with vincristine 0.25 mg/m2 i.v. on days 1 to 4 and prednisone 1 gm/m2 on days 1 and 3. Chemotherapy was repeated every 2 weeks. Of 15 evaluable patients, five achieved a partial response and four stable disease. Three patients with partial response and three with stable disease relapsed at 6, 7, and 16 and at 5, 9, and 10 months, respectively. The median survival for all patients was 10 1/2 months and it ranged from 1 to 21 + months. The median survival in responders was not reached at 13 months. Onset of antitumor effect was observed within the first 2 weeks. Symptomatic relief of bone pain was noted within 48 hours in responders and nonresponders. Improvement in bone marrow cellularity and decrease in plasma cell infiltration was documented in more than one-half of the responders. Tolerance to the treatment was good. No hematologic or other significant toxicity was observed.

Adult↗
PubMed1985

Near-triploid Ph-positive leukemia.

Tetraploid populations have been observed in various types of leukemia, but relatively few reports exist of triploid cell populations in acute or chronic leukemia. We report two cases of Ph-positive leukemia with a modal triploid cell population. Examination of peripheral blood from a 3-year-old boy with Ph-positive acute lymphoblastic leukemia (ALL) and a 68-year-old male with Ph-positive chronic myelocytic leukemia (CML) in blastic crisis revealed modal populations of 72 and 63 chromosomes, respectively. G-banding analysis of both cases revealed the following: karyotypic instability (no clonality), dominant trisomy, and the random association of the Ph chromosome with gains and losses of chromosomes involved in this translocation. The cytogenetic evidence obtained suggests that the triploid cell populations were not derived from a duplication of a hypodiploid cell population, but resulted from random loss of chromosomes from tetraploid cell populations derived from duplication of pseudodiploid cells.

Aged↗
PubMed1985

Cytogenetic studies of stimulated lymphocytes in hairy cell leukemia.

Using a sister chromatid differentiation (SCD) technique, cell cycle analysis in lymphocytes from two patients with hairy cell leukemia (HCL) revealed it to be similar to cell cycle progression of normal lymphocytes stimulated with lipopolysaccharide W from Escherichia coli 0.55:B5 (LPS). It appears that LPS can readily stimulate the leukemic cells of HCL into mitosis. In the two cases of B cell HCL studied, one (case 1) was revealed to have an abnormal clone with a missing chromosome #22 that was related to the production of lambda-chains.

Adult↗
PubMed1985

Two 14q+ chromosomes in malignant lymphoma: crucial cytogenetic changes on 14q.

We encountered a 36-year-old white male patient with poorly differentiated lymphocytic lymphoma, whose lymph node cells showed a clonal cytogenetic change involving chromosome #14, i.e., 47,XY, + 2,der(14),t(14;14)(14pter----14q32;14q24----14q32++ +). In addition to this change, cells with a translocation between chromosomes #2 and another #14 [t(2;14)(q21;q24)], as well as a missing chromosome #8 were found. We have reviewed the literature dealing with two or more changes affecting chromosome #14 and discussed the importance of the cytogenetic change at band 14q32 in malignant lymphoma.

Adult↗
PubMed1985

The use of a porous hydroxylapatite implant in periodontal defects. I. Clinical results after six months.

Twenty-five patients with advanced periodontal destruction were used in the study. Following initial therapy, two angular interproximal defects were selected in each patient. During flap surgery a porous hydroxylapatite implant shaped to fit the periodontal defect was placed in one defect, the other defect was used as nonimplanted control. The material used for implantation was a hydroxylapatite replicate of coral from the genus Porites, with a pore size of 190 to 220 micron. Clinical parameters were measured prior to flap surgery for each of the defects. An occlusal acrylic stent was used to give a stable reference point for pocket depth, attachment level and gingival margin height measurements. Also gingival fluid, gingival inflammation, plaque index and tooth mobility were recorded. Periapical radiographs using a standardized positioning device were also taken. At the time of surgery, the depth of the osseous defect and the height of the alveolar crest were recorded. After 6 months the clinical measurements were repeated and a re-entry surgery was carried out in 15 selected sites. Results showed that the porous implant produced statistically significant reduction in pocket depth, in the depth of osseous lesion, and a statistically significant gain in attachment level, as compared to control areas.

Adult↗
PubMed1985

Coexistence of myeloid metaplasia with myelofibrosis and hairy-cell leukemia.

A 42-year-old man with severe pancytopenia and myelofibrosis underwent splenectomy seven months after onset of his symptoms; the leukocyte, platelet, and hematocrit levels became normal. Myeloid metaplasia was identified in the liver and spleen. Progressive lymphocytosis started eight months after splenectomy, and after 66 months a florid hairy-cell leukemia was diagnosed; the circulating cells were B type with micro K surface markers. Anemia and thrombocytopenia reappeared and were controlled initially with daily prednisone; chlorambucil was later added. At that time, the peripheral blood had more than 150 megaloblastoid-appearing normoblasts per 100 leukocytes. The PAS stain was positive in 95% to 100% of these cells; the B-cell surface markers were no longer identified. Further treatment failed to control the lymphoproliferative and myeloproliferative syndromes; the patient died 99 months after splenectomy. On autopsy, infiltration by hairy-cell leukemia cells and erythroid precursors was observed in the bone marrow, liver, lymph nodes, and other organs.

Adult↗
PubMed1984

T-suppressor cell chronic lymphocytic leukemia. Phenotypic characterization by monoclonal antibodies.

A patient with long standing seropositive rheumatoid arthritis developed lymphocytosis which phenotypically involved the cytotoxic/suppressor T-lymphocyte population. There are 10 reported instances of this new disease entity described as "chronic T-cell lymphocytosis with neutropenia" or "chronic suppressor T-cell lymphocytic leukemia." The disease is characterized by hepatosplenomegaly, neutropenia, and the frequent presence of rheumatoid factor without clinical evidence of rheumatoid arthritis. Splenectomy in our patient, as well as in other instances where undertaken, has been ineffective in alleviating the neutropenia. The peripheral blood lymphocytes in our patient were OKT-3+, OKT-5+, OKT-8+, OKT-11+, cALL-, OKT-6-, TdT-. They possessed ADCC but no NK activity and did not suppress PWM-induced B-cell differentiation in spite of the presence of Fc receptor for IgG. Since the lymphocytosis of OKT-8+ cells appears to be clonal, it is suggested that the disease be designated chronic suppressor T-cell lymphocytic leukemia.

Antibodies, Monoclonal↗