Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A bone-resorbing product of mouse spleen cells found to have differentiation-inducing activity was most probably leukaemia inhibitory factor (LIF). This revealed that LIF is a cytokine active on bone, in addition to its several other sites of action. In organ culture of newborn mouse bone, recombinant LIF promoted bone resorption by a prostaglandin-dependent process. Resorption by isolated rat osteoclasts was also promoted by LIF through an initial action on osteoblasts which was receptor-mediated. Incorporation of [3H]thymidine into DNA was increased by LIF in cells (most probably osteoblasts) of the newborn mouse bones. Osteoblasts have been shown to produce LIF, and the amount is increased by treatment with retinoic acid or TNF-alpha. LIF also acts directly on osteoblasts to inhibit plasminogen activator activity, by stimulating the synthesis of plasminogen activator inhibitor 1 mRNA and protein. The latter actions are very similar to those of TGF-beta. Again like TGF-beta, LIF was ineffective in promoting bone resorption in vitro in fetal rat long bones. These results, together with the in vivo data showing that high circulating levels of LIF in the mouse are accompanied by a substantial increase in trabecular bone mass, indicate that LIF is another cytokine with potent actions on bone and potentially important interactions with other osteotrophic factors.
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PMID:Leukaemia inhibitory factor and bone cell function. 142 10

Plasma concentration of thrombin-antithrombin III complex (TAT), tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor 1 (PAI-1), PAI-2, D-dimer complex and urokinase-plasminogen activator (u-PA) activity were studied in 30 patients with acute nonlymphoblastic leukemia (ANLL), before and during antileukemic therapy. Fifteen patients showed signs of disseminated intravascular coagulation (DIC), 10 of them classified as M3, 2 as M2 and 3 as M5 subtypes. The initial levels of TAT complex were elevated in all ANLL patients. This increase was more pronounced in patients with DIC (p less than 0.05). TAT increased significantly during the treatment period in all cases. u-PA and PAI-1 levels were elevated but there were no statistically significant differences between patients with and without DIC. PAI-2 levels were below the limit of detection in controls and in patients. However, the initially elevated D-dimer complex levels were significantly higher in DIC cases (p less than 0.01) and they increased during the treatment period. A significant and positive correlation between D-dimer and TAT complex values was found in DIC patients (r = 0.68, p less than 0.001). The high TAT complex and D-dimer levels further increased during chemotherapy treatment strongly suggest a hypercoagulable state with secondary activation of fibrinolysis not severe enough to manifest itself as clinically evident DIC in the majority of cases.
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PMID:Increase in the D-dimer levels during treatment in patients with acute myelogenous leukemia. 142 55

Poly(L-lactic acid) (L-PLA) microspheres containing 5-fluoro-2'-deoxyuridine (FUdR) or its ester prodrugs with saturated aliphatic acids (FUdR-Cn, n = 2, 3, 4, 5, 6, 8, 10 and 12) were prepared. The physicochemical and biological properties and antitumor activity of the L-PLA microspheres were studied. The lipophilicity of FUdR-Cn was increased by prolonging its acyl-promoieties. FUdR-C5, FUdR-C6, FUdR-C8, FUdR-C10 and FUdR-C12 showed almost complete incorporation into the microspheres, while incorporation of hydrophilic FUdR and FUdR-C2 was poor. The sustained release of FUdR from the microspheres containing FUdR-C4, FUdR-C5 and FUdR-C6 was obtained in the presence of esterase, and higher antitumor activity against P388 leukemia was observed in vivo. On the other hand, the release rates of FUdR from the microspheres containing FUdR-C10 and FUdR-C12 were very small, and their antitumor activity was much smaller than that of the free prodrug suspension. Effects of the susceptibility to enzymatic hydrolysis and the physiocochemical properties of prodrugs on the release profiles of FUdR from spheres were discussed.
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PMID:Controlled release of 5-fluoro-2'-deoxyuridine by the combination of prodrug and polymer matrix. 182 27

Vinorelbine is a new 5' nor Vinca alkaloid, active by i.v. route, in various types of cancer disease such as non-small cell lung cancer and advanced breast cancer. In order to evaluate the possibility of using this drug for local treatment of cancer, Vinorelbine-loaded bioresorbable polymeric implants were prepared using a copolymer of D,L-lactic and glycolic acids (PLA 37.5 GA 25). According to the manufacturing process, the 1.2-mm-diameter cylindrical rods obtained had a drug content of 1, 5, or 20% (w/w) and released half of their content within about 6 days in vitro. In vivo release in rats was slower, half of the drug being released after about 14 days. A dose-dependent antitumoral effect was observed in mice (solid P388 leukemia model) when implants were administered into or in contact with the tumor. At highest drug loads and when administered soon after tumor implantation, Vinorelbine implants were more effective than i.v. administration (median survival time of treated animals related to untreated controls, greater than 360 versus 188). In dogs, results of toxicity experiments revealed that administration of implants in vital organs must be avoided. On the contrary, s.c. administration was well tolerated. A transient local necrosis was observed in the days following implantation, but normal skin was recovered after about 10 weeks. Thus, a clinical trial was conducted on patients with head and neck cancer; implantation of 20% loaded polymeric implants into the tumor sites succeeded in 8 of 9 patients. The sole failure was attributed to the unusual hardness of the tumor tissue. Except for a local transient inflammatory reaction (easily treated with nonsteroidal antiinflammatory agents), no other sign of toxicity was detected, and patients tolerated the device well. Fourteen days after implantation, patients underwent their planned surgery, and the implants were recovered. Residual drug content varied from 24 to 55%. In all cases, there was a clearly delimited necrotic area around the implant, ranging from 0.5 to 3.5 cm in diameter. In the smallest tumors, necrosis was also observed in the normal tissue inside this area. These results invite further studies to evaluate such drug-loaded polymeric implants.
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PMID:Experimental studies and preliminary clinical trial of vinorelbine-loaded polymeric bioresorbable implants for the local treatment of solid tumors. 191 58

Understanding of the leukemic evolution of human non-Hodgkin's lymphomas is hindered by the lack of appropriate animal models. For this purpose, a highly leukemic cell line NQ22, derived from a MCF 247 murine leukemia virus (MuLV)-induced murine T-cell lymphoma, was established, and its preliminary characterization is described. The NQ22 cell line is easily transplantable subcutaneously (s.c.) into syngeneic AKR mice exhibiting early peripheral blood invasion and widespread dissemination with a leukemic pattern of infiltration. Such peculiar in vivo behavior is a stable phenotypic feature, probably determined genetically. Biological and differentiation characteristics of the NQ22 cell line were analyzed and compared to those of other non-leukemic T-lymphoma lines. In addition, no evidence of possible involvement of plasminogen activator (PA) enzymes and of their inhibitors (PAI) in the spreading ability of NQ22 cells was observed.
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PMID:Establishment and characterization of a leukemic murine cell line derived from MCF 247 MuLV-induced T-cell lymphoma. 215 41

Specific binding of leukemia-inhibitory factor (LIF) to osteoblasts, but not multinucleated osteoclasts, was demonstrated by receptor autoradiography by using cells isolated from newborn rat long bones. The clonal rat osteogenic sarcoma cells, UMR 106-06, which have several phenotypic properties of osteoblasts, expressed 300 LIF receptors per cell, with an apparent KD of 60 pM. Treatment of calvarial osteoblasts or UMR 106-01 cells with LIF resulted in a dose-dependent inhibition of plasminogen activator (PA) activity. Both calvarial osteoblasts and osteogenic sarcoma cells were shown by Western blotting and reverse fibrin autography to produce plasminogen activator inhibitor-1 (PAI-1), the production of which was increased by LIF treatment. Northern blot analysis revealed that LIF treatment resulted in a rapid (peak 1 hour), dose-dependent increase in mRNA for PAI-1. LIF treatment of the preosteoblast cell line, UMR 201, enhanced the alkaline phosphatase response of these cells to retinoic acid. Each of the osteoblast-like cell types (calvarial osteoblasts, UMR 106-06, and UMR 201) was shown to produce LIF by bioassay and, by using the polymerase chain reaction (PCR), was shown to express low levels of mRNA for LIF. These data establish that cells of the osteoblast lineage are targets for LIF action. The reported anabolic effects of this cytokine on bone formation in vivo could be related to inhibition of protease activity. LIF may be an important paracrine modulator in bone, or perhaps an autocrine one, based on the evidence for its production by osteoblasts and osteoblast-like cells.
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PMID:Osteoblasts display receptors for and responses to leukemia-inhibitory factor. 217 Apr 27

Seventy-two consecutive and previously untreated adults with acute non-lymphoblastic leukaemia (ANLL), having a median age of 36 years (range 12 to 71), were prospectively randomised to receive conventional doses of cytosine arabinoside and doxorubicin combined with either etoposide (CTR III) or 6-thioguanine (DAT). Morbidity was comparable between the two regimens and complete remission (CR) rates of 52% and 62% respectively (p greater than 0.50) were not influenced by age above or below 50 years, initial white cell count, French-American-British classification, or race. However, growth pattern in the GM: CFUc assay was found to identify a subgroup of patients who had a significantly higher CR rate. Similarly, the secretion of tissue plasminogen activator by leukaemic blasts in vitro uniformly predicted for primary drug resistance, whereas a CR rate of 68% was associated with production of the urokinase type or a mixture of both enzymes. Remission duration and survival did not differ between these two forms of chemotherapy, nor were they influenced by immunotherapy with C. parvum or the duration of maintenance therapy, whereas age below 50 and the species of plasminogen activator secreted were significant prognostic factors. It is concluded that etoposide can be substituted for 6-thioguanine in these cytosine arabinoside and doxorubicin-containing regimens and that for both combinations the most sensitive prognostic factor for CR and survival is the species of plasminogen activator secreted in vitro by the leukaemic blasts.
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PMID:Chemotherapy of adult acute nonlymphoblastic leukaemia. 220 94

The fibrinolytic system was studied in 46 patients with acute leukaemia at diagnosis. Untreated patients (with the sole exception of the M3 subgroup) showed an inhibition of fibrinolytic activity, measured by the euglobulin lysis time and area. This inhibition was accompanied by reduced t-PA antigen and t-PA inhibitor activity. No correlation was found between the above-mentioned fibrinolytic parameters and the biochemical haematological values considered, nor with clinical and/or laboratory features of DIC, fever, liver failure. The decrease in immunological plasminogen and functional alpha 2-antiplasmin, showed a significant correlation with the presence of clinical and/or laboratory signs of DIC, as diagnosed on the basis of concomitant increase in fibrin monomers, plasmatic fibrinopeptide A and serum FDP.
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PMID:Depressed fibrinolysis in patients with acute leukaemia. 244 34

Three consecutive patients with acute promyelocytic leukaemia who presented with severe haemorrhagic syndromes were studied and the findings contrasted with those of two patients with classical defibrination after electroshock or complicated labour. The leukaemic patients showed no depletion of fibrinogen. There was no evidence of disordered thrombin generation by either intrinsic or extrinsic pathway sufficient to account for their haemorrhage. All, however, showed strikingly enhanced fibrinolytic activity, which could have accounted for bleeding. This fibrinolytic disorder was characterized by free u-PA in the plasma and differed from that seen after classical defibrination, where free t-PA was observed. U-PA was found also in malignant promyelocytes, which may be the source of u-PA activity in the patients' plasma. Bleeding in promyelocytic leukaemia may be primarily a fibrinolytic disorder.
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PMID:The bleeding disorder in acute promyelocytic leukaemia: fibrinolysis due to u-PA rather than defibrination. 249 42

The secretion of tissue plasminogen activator (t-PA), urokinase (u-PA) and their inhibitors by the human leukemia cell line K562 was examined. K562 cells normally secrete both t-PA and u-PA in a ratio of 3:1. After addition of 10 or 1 ng/mL phorbol myristate acetate (PMA) to K562 cells, a marked decrease in enzymatic activity is observed in the medium. However, when t-PA antigen rather than activity is measured, an increased amount is found in the medium under these conditions. PMA also induces secretion of the two inhibitors of plasminogen activator: plasminogen activator inhibitor 1 (PAI-1) and plasminogen activator inhibitor 2 (PAI-2). This accounts for the decrease in total enzymatic activity under conditions when production of t-PA antigen is increased. A study of the time course of induction revealed that the synthesis of plasminogen activator occurred before that of its inhibitors. Low concentrations of PMA (0.1 ng/mL) induce t-PA antigen primarily and not the inhibitors. This results in an increase in total enzymatic activity, with 94% of the secreted activity being t-PA. Thus, the secretion of plasminogen activators and their inhibitors can be manipulated in certain leukemic cells by inducers such as PMA.
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PMID:Regulation and secretion of plasminogen activators and their inhibitors in a human leukemic cell line (K562). 250 6


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