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Biomedical subjects

X Zhao

Publications and source records attributed to X Zhao.

At least 703 records · Page 39Linked to original sources
PubMed1988

Establishment of human mesothelioma cell lines (MS-1, -2) and production of a monoclonal antibody (anti-MS) with diagnostic and therapeutic potential.

We have established and characterized two mesothelioma cell lines, MS-1 and MS-2, in four attempts at long-term culture of these cells. Both MS-1 and MS-2 cells consistently express cytokeratin and vimentin, and both have long, slender microvilli. The cells that grew indefinitely (MS-1, MS-2) had a higher DNA index and a higher nucleus:cytoplasm ratio than did those cells that failed to grow (MS-3, MS-4). All mesothelioma cells, both in short- and in long-term culture, responded to phorbol ester induction by displaying morphological differentiation, such as an increase in the number of microvilli. The distribution of vimentin and cytokeratin in the cells, however, remained the same regardless of the growth pattern or the phorbol-ester treatment of the cells. We have used MS-1 cells to produce a monoclonal antibody (anti-MS) that reacts with mesothelioma cells, but rarely with reactive or normal mesothelial cells or with cells of normal tissues. The antibody does not induce the modulation of antigen, and it causes no direct or complement-mediated cytotoxicity of MS-1 or MS-2 cells. If a toxin or an isotope conjugate of the antibody is used, it may be valuable in the near future to test it for use in immunoimaging or immunotherapy.

Antibodies, Monoclonal↗
PubMed1988

Reed-Sternberg cells in Hodgkin's cell lines HDLM, L-428, and KM-H2 are not actively replicating: lack of bromodeoxyuridine uptake by multinuclear cells in culture.

We compared the proliferation of mononuclear and multinuclear cells in four Hodgkin's cell lines, HDLM-1, HDLM-1d, L-428, and KM-H2, by examining their capacity to incorporate bromodeoxyuridine (BrdUrd) into nuclei. Approximately 5% of all cells in HDLM-1 cultures had two or more nuclei, a characteristic of Reed-Sternberg (RS) cells. Unlike mononuclear Hodgkin's (H) cells, these RS cells exhibited no uptake, or only minimal uptake of BrdUrd, suggesting that they did not replicate actively. Cytogenetic study showed that 25% of the HDLM-1 cells contained a tetraploid (4X) set of chromosomes with a characteristic two-peak distribution. Following treatment of HDLM-1 cells with phorbol ester, the percentages of 4X cells and RS cells increased to 50% and 12%, respectively. This increase in RS cells was not likely to be due to cell fusion as shown by the absence of hybridization of BrdUrd-positive and -negative nuclei. Phorbol ester has a short-term effect of blocking the exit of cells from G1 into S phase, but no effect on the transition from S phase to G2/M phase. The block is more prominent in 2X cells than in 4X cells, which may explain the increase in percentage of 4X cells in phorbol ester-treated cultures. In addition, phorbol ester induced the differentiation of H-RS cells, which was accompanied by loss of the marker HeFi-1 from the cell surface. Approximately one third of the RS cells did not express HeFi-1, or expressed only minimal amounts. The findings led us to the following conclusions: (1) The 4X cells probably are formed from 2X H cells as a result of disturbed cytokinesis, but not a cell fusion. (2) A considerable number of 4X cells were H cells, because the number of 4X cells consistently exceeded that of RS cells. (3) Since mitotic figures are extremely rare in RS cells and these cells did not show active BrdUrd uptake, the increased number of RS cells must also be a consequence of disturbed cytokinesis of H cells or a result of nuclear transformation (twisting, convolution, or separation of the nucleus) in H cells. (4) Most RS cells lose their proliferating capacity and some RS cells may undergo further differentiation. Uptake of BrdUrd and phorbol ester induction were also studied on the other three H-RS cell lines, HDLM-1d, L-428, and KM-H2, with results similar to those for HDLM-1.

Biological Transport↗
PubMed1987

Inositol-phosphate response to oxytocin stimulation in dispersed bovine mammary cells.

The effect of oxytocin on the breakdown of phosphoinositides in dispersed bovine mammary cells was studied. In the presence of 10 mM LiCl, addition of oxytocin to dispersed bovine mammary cells in which phosphatidylinositol was pre-labelled caused a time and dose-dependent increase in radioactive inositol monophosphate incorporation. These results suggested that the breakdown of phosphoinositides may be the linkage between the oxytocin receptor and contraction of mammary myoepithelial cells.

Animals↗
PubMed1987

Oxytocin receptors in bovine mammary tissue.

Oxytocin receptors were identified and characterized in bovine mammary tissue. [3H]-oxytocin was specifically bound to the 105,000 X g particulate fractions from 5 lactating cows and 5 non-lactating cows. Binding reached equilibrium by 50 min at 20 degrees C and by 8 hr at 4 degrees C. The half-time of displacement at 20 degrees C was approximately 1 hr. ACTH, TRH, angiotensin I, angiotensin II, pentagastrin, bradykinin, xenopsin and L-valyl-histidyl-L-leucyl-L-threonyl- L-prolyl-L-valyl-L-glutamyl-L-lysine were not competitive in the dose range tested at 20 degrees C. The ability of other peptides to inhibit 3H-oxytocin binding was as follows: oxytocin greater than vasotocin greater than arginine - vasopressin greater than lysine - vasopressin greater than Pen1 Phe2 Thr4 - oxytocin. The Kd of the oxytocin receptor averaged 1.66 +/- 1.19 nMol/L for lactating cows and 0.97 +/- nMol/L for non-lactating cows, respectively. The maximum number of binding sites was 0.14 +/- 0.12 nM/mg protein and 0.15 +/- 0.08 nM/mg protein for lactating cows and non-lactating cows, respectively. Identification and characterization of these receptors now makes it possible to study the dynamics of hormonal binding throughout various physiological states of the animal.

Animals↗
PubMed1987

The H-RS-like cells in infectious mononucleosis are transformed interdigitating reticulum cells.

The lymphoid tissues from patients with infectious mononucleosis or, less frequently, with other reactive conditions may contain Reed-Sternberg (RS)-like cells. These tissues also contain cells resembling the lacunar cells or lymphocytic/histiocytic (L/H) variants, which are present in the lymphocyte-predominant type of Hodgkin's disease. The phenotype of these RS- and L/H-like cells was determined with a large panel of antibodies and lectins. The cells expressed sialylated Leu-M1, Con A, LN-2, and, less frequently, interleukin-1, S-100, and peanut agglutinin receptor. They reacted negatively with two markers for RS cells, Ki-1 and HeFi-1. These RS-like cells were consistently negative for T- and B-cell markers, including immunoglobulins. The markers of the RS-like cells are distinctly different from those in B-immunoblasts, but closely resemble those in interdigitating reticulum cells. It is concluded that interdigitating reticulum cells, when stimulated, can be transformed into lacunar-, L/H-, or RS-like cells.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1987

Localization of interleukin-1 in normal or reactive lymphoid tissues and skin: abundance of IL-1 in interdigitating reticulum cells.

The distribution of interleukin 1 producing cells was determined in the human lymphoid tissues and skin using immunohistochemical staining and a rabbit anti-interleukin-1 antibody. Interleukin-1 was detected mainly in the interdigitating reticulum cells localized in the T cell zone. Approximately, 10-30% of the histiocytes were also positively stained by anti-interleukin-1. The results suggests that interdigitating reticulum cells may play an important role in the initiation and amplification of T-cell immunity.

Animals↗
PubMed1987

Extracellular matrix does not induce the proliferation, but promotes the differentiation, of Hodgkin's cell line HDLM-1.

Tumor cells from the Hodgkin's cell line HDLM-1 were cultured in extracellular matrix (ECM)-coated flasks. Within 24 hours, the cells underwent rapid differentiation, accompanied by morphologic and phenotypic changes. A slow and less prominent, but similar change was observed in HDLM-1 cells after they had been induced with phorbol ester for 5 days. The ECM-induced cells became HeFi-1-negative and expressed antigens 2H9 and 1E9 on their nuclear membranes. These cells had punctate acid-phosphatase and esterase activities. Approximately 70% of the ECM-induced cells were elongated and had long, blunt cytoplasmic projections. These findings, together with evidence the authors previously presented, indicate that H-RS cells are related to interdigitating reticulum cells. The authors believe that the ECM-induced HDLM-1 cells can be used as an important model for studies of the nature and cell lineage of Hodgkin's disease.

Antigens, Neoplasm↗
PubMed1987

Mechanism of the therapeutic effect of anisodamine in disseminated intravascular coagulation: study of platelet adhesion and aggregation, malondialdehyde, thromboxane B2, 6-keto-prostaglandin F1 alpha, and microcirculation.

Acute disseminated intravascular coagulation (DIC) is a life-threatening condition that may be encountered in many situations, especially in cases of shock with uncontrollable hemorrhage. Anisodamine, an alkaloid extracted from a Chinese herb, is well known for its dramatic therapeutic effect on DIC. Sixty male rabbits were used to establish an acute DIC model. A total of 240 blood samples were taken for laboratory assays of changes in blood coagulation factors, platelet count, platelet adhesion, platelet aggregation, malondialdehyde (MDA), thromboxane B2 (TXB2), and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha). Changes of the microcirculatory status and the rate of the blood flow in the conjunctival capillaries of 60 rabbits were observed with WXS-II microcirculation microscope. Pathological sections of the lungs and kidneys were studied. Our investigation showed the presence of microthrombi in the microvasculature. After treatment with anisodamine, the prothrombin time stayed in the normal range, fibrinogen consumption was lessened, adenosine-diphosphate-induced platelet aggregation was inhibited, thromboxane B2 and malondialdehyde concentrations were significantly lower than in the control group, and the elevated quantity of 6-keto-PGF1 alpha was spared. We concluded that the anti-platelet-aggregating, microcirculation-facilitating, thromboxane-B2-inhibiting, malondialdehyde-inhibiting, and 6-keto-PGF1 alpha-sparing effects of anisodamine are the important mechanisms of its dramatic therapeutic effect on DIC.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

Expression of interleukin-1 in Reed-Sternberg cells and neoplastic cells from true histiocytic malignancies.

Interleukin-1, a peptide produced by monocytes, histiocytes, and interdigitating reticulum cells, plays an important role in the regulation of immune function. In this styde, we examined the production of interleukin-1 in 115 patients with a variety of human lymphomas by using a rabbit anti-interleukin-1 antibody and the immunoperoxidase technique. Interleukin-1 was detected in Reed-Sternberg cells from 20 patients with Hodgkin's disease as well as in neoplastic cells from 9 patients with true histiocytic lymphoma or malignant histiocytosis. In the other 86 cases, which included T- and B-cell lymphomas, no interleukin-1 could be detected. This result indicates a close relationship between Hodgkin's disease and true histiocytic malignancies and provides additional evidence to support our hypothesis that Reed-Sternberg cells are related to interdigitating reticulum cells.

Animals↗