Wireless capsule endoscopic finding in Cronkhite-Canada syndrome.
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Aged↗
Biomedical subjects
B M Wang
Publications and source records attributed to B M Wang.
Adenovirus-mediated combined suicide gene and interleukin-2 gene therapy for the treatment of established tumor and induction of antitumor immunity.
The antitumor effect of the combined transfer of a suicide gene and a cytokine gene was evaluated in the present study. Adenoviruses expressing Escherichia coli cytosine deaminase (AdCD) and adenoviruses expressing murine interleukin-2 (AdIL-2) were utilized for the treatment of established tumors. The mice were inoculated s.c. with FBL-3 erythroleukemia cells and 3 days later received an intratumoral injection of AdCD in the presence or absence of AdIL-2 followed by intraperitoneal 5-fluorocytosine (5-FC) administration. The results demonstrated that tumor-bearing mice treated with AdCD/5-FC in combination with AdIL-2 showed more potent inhibition of tumor growth and survived much longer than did mice treated with AdCD/5-FC, AdIL-2, adenovirus expressing beta-galactosidase/5-FC or phosphate-buffered saline. The tumor mass showed obvious necrosis and inflammatory cell infiltration, and more CD4+ and CD8+ T cells infiltrating the tumor after combined therapy. The splenic natural killer and cytotoxic T lymphocyte activities increased significantly in the mice after combined therapy with AdCD/5-FC/AdIL-2. Our results demonstrate that therapy combining a suicide gene and IL-2 gene can inhibit the growth of established tumors in mice significantly and induce antitumor immunity of the host efficiently.
Adenoviridae↗
Adenovirus-mediated GM-CSF gene and cytosine deaminase gene transfer followed by 5-fluorocytosine administration elicit more potent antitumor response in tumor-bearing mice.
Antitumor effects of combined transfer of suicide and cytokine genes were investigated in this study. Adenovirus harboring E. coli cytosine deaminase gene (AdCD) and adenovirus harboring murine granulocyte-macrophage colony-stimulating factor gene (AdGMCSF) were used simultaneously for in vivo gene transfer in melanoma-bearing mice. Growth inhibition of established tumors and prolongation of survival period were observed more significantly in tumor-bearing mice after transfection with AdGMCSF and AdCD followed by continuous injection of prodrug 5-fluorocytosine (5FC) when compared with mice treated with control adenovirus AdlacZ/5FC, AdCD/5FC or AdGMCSF alone (P < 0.01). After combined therapy the expression of MHC-I (H-2Db) and B7-1 molecules on freshly isolated tumor cells increased greatly and more dendritic cells and CD8+ T cells infiltrated into the tumor mass. The activity of specific cytotoxic T lymphocytes was also found to be induced more significantly after the combined therapy. Further experiments showed that apoptosis of tumor cells and induction of antitumor immune response might be involved in the mechanisms of the tumor cell killing by the combined therapy. Our results demonstrated that combined transfer of the GM-CSF and CD suicide genes, being able to inhibit the growth of melanoma synergistically and induce specific antitumor immune response efficiently, thus addressing the drawbacks of suicide gene therapy or cytokine gene therapy which were proved to be not satisfactory when used alone, might be of therapeutic potential for gene therapy of cancer.
Adenoviridae↗
Diagnosing pulmonary alveolar proteinosis. A review and an update.
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Bronchoalveolar Lavage Fluid↗
Chronic mild dyspnea on exertion and diffuse alveolar infiltrates in a 37-year-old man.
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Adult↗
A newly developed serum-free culture system: clonal growth of human acute myelogeneous leukemia (AML) progenitors--a report of 14 AML cases.
A new serum-free culture (SFC) system for human AML-CFU was established and the colony-promoting activity of four recombinant human hematopoietic growth factors (rhHGFs) including granulocyte-macrophage colony-stimulating factor (rhGM-CSF), interleukin-3 (rhIL-3), erythropoietin (rhEPO) and newly developed stem cell factor (rhSCF) were investigated in this SFC system. Under the orthogonal design condition, it was found that human AML-CFU presented optimal clonal growth in an environment of bovine serum albumin (0.6%), saturated human transferrin (2 x 10(-6) mol/L), cholesterol (2.8 micrograms/ml), bovine insulin (15 micrograms/ml), bovine hemin (0.05 mmol/L), linoleic acid (2.8 micrograms/ml), and IMDM. Spontaneously growing colonies were observed in 11 out of 14 cases studied. The plating efficiencies obtained by culturing with rhGM-CSF, rhIL-3, and rhSCF were 0.776 +/- 0.621%, 0.574 +/- 0.510%, and 0.647 +/- 0.543% (mean +/- s), respectively. There was one case (M3b) showing no response to all HGFs in both SFC ad SCC. The clonal growth of AML-CFU obtained from peripheral blood of the patient with M6 was unexpectedly marked. As a whole, the newly designed SFC system has been demonstrated to be useful for culture of human AML-CFU from both bone marrow and peripheral blood.
Culture Media, Serum-Free↗
An effective method for depleting mature T lymphocytes from bone marrow cells--two-step Percoll centrifugation.
In the present paper we have observed the effect of discontinuous gradient two-step Percoll centrifugation on depleting mature T lymphocytes from normal bone marrow. The pre-/post-Percoll percentage of CD34+, and Leu4+ cells in MNC was counted by using APAAP technique. As the two-step Percoll centrifugation is simple, and time saving, and decreases the incidence of contamination of cultured cells as well, This technique may be of value in serum-free culture of hematopoietic cells and immunological studies.
Antigens, CD↗
[Effect of recombinant human stem cell factor (rhSCF) on self-renewal of stem/progenitor cells of human acute myelogenous leukemia].
Using serum-free culture system and liquid/semi-solid dual culture technique, we examined the effect of rhSCF on self-renewal of the stem/progenitor cells of human acute myelogenous leukemia (AML-CFU). The results revealed that the rhSCF as a hematopoietic growth factor (HGF) exerted its effect hierarchically earlier than interleukin-3 and granulocyte/macrophage colony-stimulating factor on AML-CFU. rhSCF, whether used alone or in combination with other HGFs, showed potential maintenance of self-renewal of AML-CFU in most AML patients studied. However, considerable discrepancy existed in maintenance among various FAB types of patients or even in patients with the same FAB type. It is suggested that SCF may play an important role in the pathological development of AML.
Adolescent↗
[Enzyme cytochemistry and morphometric study of the effects of macrophages on A549 pulmonary alveolar cell carcinoma cell line].
In order to study the mechanism of the effects of M phi on tumor cells, enzyme cytochemistry and morphometry were used to investigate the activities of cytochrome oxidase (CO), succinate dehydrogenase (SD), lactate dehydrogenase (LDH) and acid phosphatase (ACP) in A549 pulmonary alveolar cell carcinoma cells which had been interacted with normal and CP-activated macrophages respectively. It was found that when E/T = 10:1, the enzyme activity of the cancer cell mitochondria, CO, SD, LDH were decreased, and when E/T = 20:1, the activity of the lysosomal enzyme ACP was increased. These results indicate that when the E/T ratio was appropriate, activated M phi may injure the mitochondria and lysosomes and affect the aerobic respiration and oxidative phosphorylation of cancer cells. This may be one of the cytostatic and cytotoxic mechanisms of activated M phi on tumor cells.
Acid Phosphatase↗
The significance of Ki-67, BrdU and OKT9 expression in determination of myelodysplastic syndromes by use of APAAP technique.
Monoclonal antibodies (McAb) to Ki-67, BrdU and OKT9 were used in APAAP technique for determining the proliferative cells of 46 myelodysplastic syndromes (MDS) with 16 serving as normal controls. According to Ki-67 positive labelling, the proliferative fractions of bone marrow cells can be divided into low (< 25%), intermediate (25%-35%), and high (> 35%) grades. The labelling positivity of Ki-67, BrdU and OKT9 in MDS was all higher than that of the controls. Furthermore, the positive percentages of these three McAbs were significantly correlated. From the results of our experiment, an increase in proliferative fraction was related to clinical classification, prognosis, and therapy of MDS. On the other hand, the positive percentage of Ki-67 > 40% and BrdU > 30% or ratio of BrdU to Ki-67 > 80% may be considered as parameters for unfavourable prognosis.
Adolescent↗
[Effects of various recombinant human hematopoietic growth factors on proliferation of blast cells in acute myeloid leukemia in vitro].
In vitro proliferative response of the blast cells from 21 AML patients to hematopoietic growth factors (IL-3, GM-CSF, G-CSF and MCSF) was investigated. Proliferation of AML cells in the majority of cases was induced or promoted by one or more CSFs, among which the stimulation of IL-3 was the most effective. Spontaneous proliferation of the blast cells was also observed in half of the cases and could be inhibited as well as promoted by some CSFs. It is suggested that in vitro proliferation of AML cells varies from patient to patient and that CSF plays important roles in leukemogenesis.
Adolescent↗
A functional leuABCD operon is required for leucine synthesis by the tyrosine-repressible transaminase in Escherichia coli K-12.
In Escherichia coli K-12, two enzymes, encoded by ilvE and tyrB, catalyze the amination of 2-ketoisocaproate (2-KIC) to form leucine. Although leucine-requiring derivatives of an ilvE strain that are unable to grow on 2-KIC were expected to have mutations only in tyrB, mapping studies showed that one such mutation was tightly linked to the leu operon (at 1.5 min), not to tyrB (at 92 min). Chromosomal fragments cloned because they complemented this mutation were found to complement leu mutations, and vice versa, but none of these fragments complemented a tyrB mutation. The Tn5 insertion and flanking host DNA from this anomalous mutant was cloned in vivo, using Mu dII4042, and an in vivo procedure was developed to isolate deletion derivatives of Tn5-containing plasmids. These deletion plasmids were used to determine the DNA sequences flanking the transposon. The data showed that Tn5 was inserted between bp 122 and 132 in the leu leader. In addition, other ilvE leu double mutants were found to be unable to grow on 2-KIC in place of leucine. The accumulation of 2-ketoisovalerate in ilvE leu double mutants was shown to interfere with 2-KIC amination by the tyrB-encoded transaminase and also by the aspC- and avtA-encoded transaminases (which are able to catalyze this reaction in vivo when the corresponding genes are present on multicopy plasmids).
Bacteriophages↗
[Bone marrow histological changes in myelodysplastic syndrome and its clinical significance].
The authors compared bone marrow histological changes in 28 cases of myelodysplastic syndrome (MDS), 21 cases of aplastic anemia and 8 cases of hemolytic anemia. It is shown that abnormal localization of immature precursors (ALIP) is a characteristic change in MDS. The presence of erythroblastic islands and the variance of morphology of megakaryocytes are valuable for diagnosis. The histological method for the observation of lymphoid micromegakaryocytes is not so accurate as cytological method. "ALIP" can more or less help to evaluate the prognosis of MDS. According to the histological changes, it is easy to differentiate the three types of anemia we studied.
Adolescent↗
Monoclonal anti-human T cell antibody and PAP-s conjugate--preparation and selective cytotoxic properties on leukemic cell.
Pokeweed antiviral protein (PAP-s) was prepared from seeds of Phytolacca americana. Monoclonal antibody against human pan-T lymphocyte Wu71 was linked to PAP-s by a disulfide bond. The results of SDS-PAGE, double immunodiffusion of active monoclonal antibody and PAP-s showed that the conjugate was highly cytotoxic to the human T-leukemic cell line CEM, but not to antigen-negative cell line SP2/O. At a concentration of 10(-9) mol/L, 76.4% of the target cells were killed, as compared with 10.1% at 10(-9) mol/L of free PAP-s. Treatment of the CEM cells with conjugate at 10(-9) mol/L reduced their rate of protein synthesis by 72.4%, as determined with 14C-leucine incorporation. The immunotoxin may be useful for the in-vitro eradication of leukemic cells in autologous bone marrow transplantation to leukemia patients.
Antibodies, Monoclonal↗
Studies on human CFU-Mix microvolume culture by use of limiting dilution assay.
By use of limiting dilution assay we investigated the bipotent and pluripotent hemopoietic progenitor cells (CFU-Mix) from 21 normal adults, cultured for 32 times. The CFU-Mix counts were 35.7 colonies/10(6) bone marrow cells. According to different cellular elements they could be divided into 5 groups, namely GEMM, GE, GL, GMeg and GM phi. It was suggested that differentiation of the stem cell is of stochastic process, influenced by different hemopoietic growth factors and cellular microenvironment. Our model seems to be suitable for studying differentiation of the stem cells. The rates of 3H-TdR and 55 + 59Fe incorporation were determined, and the 2nd day of culture was found to be the delayed stage of cell growth.
Adolescent↗
Scanning electron microscopic observation of CFU-mix of normal adults and leukemic patients including two cases of myeloid-lymphoid bipotent leukemia.
We observed CFU-Mix of 4 normal adults and 11 cases of leukemia. The culture system used by us in this study represented a suitable model for studying differentiation of hemopoietic stem cells in vitro. The pathogenesis of myeloid-lymphoid bipotent leukemia were malignant changes in pluripotent hemopoietic progenitor cells. The leukemic clones showed proliferation, but did not mature in culture. It is suggested that differentiation of leukemic stem cell did not pass through CFU-Mix stage.
Adult↗
Transmission electron microscopic observation of CFU-mix culture in normal adults and leukemia patients.
By use of transmission electron microscope we demonstrated that the limiting dilution assay is an important method for investigating differentiation of hemopoietic cells in vitro. If various growth factors were added into this culture system, the stem cells of normal adults could differentiate into erythrocyte, granulocyte, megakaryocyte and macrophage, while leukemic progenitor cells could not. The colony forming cell in leukemia still had the nature of leukemic cell.
Adult↗
[Measurement of adenosine deaminase activity (ADA) in the pleural fluid].
ADA was examined in pleural fluid in cases of tuberculous and cancerous pleurisy. The level of ADA in pleural fluid in tuberculosis group (59.6 +/- 33.6 U/L) was significantly higher than that of cancerous group (13.3 +/- 4.0 U/L) (P less than 0.01). The positive rates were 90.0% and 3.3% respectively.
Adenosine Deaminase↗