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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A new in vivo system of monitoring tumor cell induced blood vessel growth using a sodium alginate entrapment process was developed. The alginate polymer of guluronic and mannuronic acids surrounds and sequesters cells from direct contact with their immediate environment, but permits diffusible angiogenic factors to pass through to induce neovascularization in the host. The alginate beads containing tumor cells were injected subcutaneously into animals and coalesced as a point source. The tumor cells are protected from direct contact with the host's immune system, so that various tumor types may be evaluated for their angiogenic potential across histocompatibility or species barriers. C57BI/6, BALB/c and nude mice as well as squirrel monkeys were used as host animals. This provided tumor cell testing in a syngeneic, allogeneic, or xenogeneic system. We found that alginate-Lewis lung carcinoma cells were potent inducers of blood vessel growth. As few as 100 alginate-Lewis lung carcinoma cells were needed to induce macroscopically visible blood vessels by 3 days. Dose-response experiments with alginate-Lewis lung carcinoma cells showed a greater level of blood vessel induction as cell numbers increased. Neovascularization was monitored qualitatively by macroscopic photography and microscopic histologic evaluation. Also, neovascularization was monitored quantitatively by measuring the level of hemoglobin at the injection site of alginate or by measuring the amount of radioactive red blood cells pooled at the injection site of the alginate beads. Both the measured levels of hemoglobin and radiolabeled red blood cells increased at the alginate site with each log increase of tumor cells delivered, which paralleled our findings at the macroscopic and microscopic level. This in vivo angiogenesis model was relatively simple and the procedures technically easy to perform. Most importantly, this model allowed both a qualitative and quantitative assessment of tumor-induced blood vessel growth.
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PMID:An in vivo quantitative angiogenesis model using tumor cells entrapped in alginate. 169

Eighteen patients with disseminated AIDS-related Kaposi's sarcoma (KS) and compromised bone marrow function were treated with a relatively non-myelosuppressive regimen of bleomycin and vincristine (BV). At study entry, the patients presented with the following median laboratory values: hemoglobin of 9.5 g/dl, granulocyte counts of 1,173/mm3, platelet counts of 218,000/mm3, and CD4 lymphocyte counts of 58/mm3. All patients had extensive Kaposi's sarcoma. Nine patients had visceral involvement: four with pulmonary involvement, two with gastrointestinal involvement, and three with both. Following a median number of seven cycles of biweekly chemotherapy, complete or partial tumor responses were achieved in 13 patients (72%). Two patients experienced bleomycin-induced skin toxicities, whereas 10 others (55%) experienced peripheral sensory neuropathy requiring vincristine dose reductions. Opportunistic infections had occurred in 11 patients prior to initiation of chemotherapy and in 16 after initiation of chemotherapy. Despite the frequent development of opportunistic infections, BV chemotherapy was relatively well tolerated and resulted in a high response rate in this patient population that presented with suboptimal marrow function and extremely low CD4 lymphocyte counts.
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PMID:Treatment of advanced Kaposi's sarcoma using a combination of bleomycin and vincristine. 169 66

Fetal hemoglobin (HbF) screening was performed on 296 cancer patients. In almost 80% of the patients with active disease (n = 197) and 35-60% of those with inactive disease (n = 99), the concentration of HbF in the blood was above the normal range. Among patients with metastatic breast carcinoma (n = 27), 89% had a high HbF concentration. The HbF level was significantly higher (p less than 0.001) in patients with active disease than in those with inactive disease. There is evidence of an ectopic production of HbF into the plasma of patients, but it will be necessary to develop a method for the prevention of hemolysis in order to establish this claim.
Tumour Biol 1991
PMID:Fetal hemoglobin screening in whole blood and in plasma of cancer patients. 170 48

An in vivo model of tumor-induced angiogenesis was used to monitor two known inhibitors of angiogenesis, protamine sulfate and the steroid tetrahydro S. Tumor cells entrapped in alginate beads were injected s.c. into mice. Blood vessel induction was measured by two quantitative methods: measurement of hemoglobin at the alginate pellet site, and pooling of radiolabeled RBC to the alginate pellet site. The two methods gave parallel results. Tetrahydro S with or without heparin inhibited blood vessel growth by 50%, and protamine sulfate inhibited blood vessel growth by 85%. These results were supported by gross morphology and histological analysis of the alginate pellet site.
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PMID:A quantitative in vivo mouse model used to assay inhibitors of tumor-induced angiogenesis. 170 73

Ultrastructural, flow cytometric, and molecular studies were performed on leukemia cells from bone marrow and pleural effusion of a 6-year-old boy diagnosed with undifferentiated (MO) leukemia, using routine histology and immunostains at diagnosis and relapse. Ultrastructurally, surface and/or intracellular ferritin particles were present on or in some blasts and the majority of blasts contained identifiable acid ferrocyanide reactive inorganic iron comparable to that seen in normal early erythroblasts. The cells lacked other evidence of differentiation, including diaminobenzidine-reactive or immunoreactive hemoglobin. Flow cytometric analysis of malignant cells showed a lack of lymphoid or myeloid markers. Anti-transferrin receptor antibody was positive on 93% of cells and antibody to glycophorin A reacted with 23% of cells. RNA blot analysis of leukemia cells with myeloperoxidase (MPO) showed an absence of appreciable levels of MPO mRNA. Chromosome analysis showed 51,XY, t(1;16)(p31;q24), +6, +10, +15, +19, +21. The oncogene c-myb, which is specifically expressed and regulated in hematopoietic cells and produces a DNA-binding protein responsible for myeloid differentiation, was found to be duplicated in the patient's tumor cells. Expression of c-jun, N-ras, c-myc, and p53 was normal. The data indicate that the malignant cells in this patient are of early erythroid lineage at diagnosis and relapse and that classification of cell lineage can be enhanced by ultrastructural Prussian blue staining. The failure of this otherwise undifferentiated leukemia to express or evolve into a myeloid phenotype is biologically and clinically distinct from previously described cases of erythroid and myeloid leukemia and may represent a previously unidentified phenotype which should be included in the spectrum of 'undifferentiated' childhood leukemia.
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PMID:Childhood undifferentiated leukemia with early erythroid markers and c-myb duplication. 170 34

Several versions of autologous transfusion are becoming increasingly popular. This review deals with their risks and side effects, which are still insufficiently documented. Basically, a number of preexisting conditions amounting to a subnormal performance and reserve capacity of several organ systems contraindicates preoperative donations, but 'critical' values of relevant parameters are still under debate. Since a preoperative deposit implies that the same individual donates several units within a few weeks, reaction rates must be related to the number of donors rather than that of donations. Viewed this way, the risk of--usually cardiocirculatory and sometimes serious--incidents is two times higher in autologous than in homologous donors. The reduction of oxygen transport capacity is a matter of concern. In order to avoid a mixed-venous p02 less than 35 mm Hg, which indicates an impending oxygen deficit, all 'non-hemoglobin' factors impacting on tissue oxygen supply must be normal even with 10 g/dl of hemoglobin; lower Hb values are undesirable. The use of erythropoietin to boost the preoperative harvest of red cells may not, by itself, be risky, but the accelerated pace of donations obviously is. The quality of cellular blood products prepared by intraoperative machine autotransfusion still leaves much to be desired. The suspicion that adenine and, especially, fibrinogen degradation products may be immunosuppressive, raises questions about the liberal use of autologous fresh frozen plasma. Bacterial contamination of reservoirs and the presence of tumor cells as well as fat droplets from bone marrow cannot be dismissed as being unimportant. Suction devices activate coagulation and fibrinolysis. Altogether, the risks of autologous transfusions, though different from those of homologous blood, require further efforts aimed at their reduction.
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PMID:[Risks and side effects of autologous transfusion]. 172 40

Bone marrow transplantation (BMT) can produce prolonged clinical remission in some patients with hematologic malignancies. Unfortunately, disease relapse may occur despite BMT. Studies in animal models and clinical experience have provided evidence that immunologic factors play an important role in preventing relapse post-BMT. To stimulate immunologic activity in patients post-BMT, we administered prolonged uninterrupted continuous infusions of low-dose recombinant interleukin-2 (rIL-2). Thirteen marrow recipients (seven autologous BMT, six CD6 T-depleted allogeneic BMT) received rIL-2 at a dose of 2 x 10(5) U/m2/d for a scheduled period of 90 days. rIL-2 was administered through a Hickman catheter with a portable pump beginning a median of 85 days after BMT. Toxicity was minimal and all treatment could be undertaken in the outpatient setting. No patient developed any signs of graft-versus-host disease, hypotension, or pulmonary capillary leak syndrome. Treatment did not affect the absolute neutrophil count or hemoglobin level, but eosinophils increased substantially in most patients. Platelet counts decreased by 20% in 10 of 13 individuals within 2 weeks, but stabilized thereafter. Despite the low dose of rIL-2 administered, significant immunologic changes were noted. Specifically, all 13 patients experienced a marked increase (fivefold to 40-fold) in natural killer (NK) cell number. Phenotypic characterization showed that the majority of NK cells were CD56bright+ CD16+ CD3-. In contrast, a minor increase in T-cell number was noted in only 4 of 13 patients. Low-dose rIL-2 treatment resulted in augmentation of in vitro cytotoxicity against K562 and COLO tumor targets. This cytotoxic activity could be dramatically enhanced by incubation with additional rIL-2 in vitro. The immunologic effects of rIL-2 treatment were similar in both autologous and allogeneic marrow recipients. Our data suggest that prolonged infusion of rIL-2 at low doses is safe and can selectively increase NK cell number and activity after BMT. Further studies to assess the impact these changes may have on disease relapse post-BMT will be undertaken.
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PMID:Clinical and immunologic effects of prolonged infusion of low-dose recombinant interleukin-2 after autologous and T-cell-depleted allogeneic bone marrow transplantation. 173 94

To determine the etiology of the increased incidence of postoperative deep venous thrombosis (DVT) in patients with carcinoma of the colon, serum levels of protein C were measured preoperatively in 65 patients with colorectal adenocarcinoma. Noninvasive lower-extremity Doppler studies were performed on all patients prior to discharge to assess patency of the deep veins. Six patients (9%) were found to have DVT. The protein C level was considered elevated if it was greater than 125% of control values and reduced if less than 75% of control values. The development of DVT was found to be independent of the serum carcinoembryonic antigen, albumin, total protein, hemoglobin, hematocrit, platelet count, prothrombin time, partial thromboplastin time, and the patient's age and percentage of ideal body weight. There was an inverse relationship between the protein C level (p less than 0.001), Dukes stage of the tumor (p less than 0.001), and the development of DVT. Linear regression analysis revealed that only the tumor stage and the protein C level could be used to predict the development of DVT. The data show that for these patients with colorectal malignancy, the development of DVT may be related to decreased levels of protein C.
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PMID:Protein C activity, stage of disease, and vascular thrombosis in colon carcinoma. 173 77

Hemoglobin and blood gas parameters, with special attention to the influence of carboxyhemoglobin, were studied in 115 head and neck cancer patients undergoing radiotherapy. In 712 weekly blood samples, the values of total hemoglobin, carboxyhemoglobin (CO-Hb), and p50 were measured and the total oxygen content in the arterial and tumor venous blood was estimated. The difference between these values express the tumor oxygen unloading capacity (t-OUC). CO-Hb ranged from 0-12% and showed a significant inverse relationship with t-OUC. This was caused by a reduced amount of effective hemoglobin combined with a left shift of the oxyhemoglobin dissociation curve (reduced p50). Overall, the tumor oxygen utilization decreased from 70% to 52% as a function of an increase in CO-Hb from 0 to 12%.
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PMID:Effect of carboxyhemoglobin on tumor oxygen unloading capacity in patients with squamous cell carcinoma of the head and neck. 173 69

Carboxyhemoglobin (HbCO) is formed when carbon monoxide is bound to hemoglobin. High levels of HbCO are known to reduce the amount of oxygen that can be carried to the tissues. This experimental study focuses on the influence of HbCO on the growth, blood flow, and radiation response of an experimental mouse tumor. The study was designed to mimic the clinical situation where heavy smokers are undergoing radiotherapy while having a high HbCO level. The tumor was a C3H mammary carcinoma grown in the feet of CDF1 mice. Chronic exposure to carbon monoxide, resulting in 10% HbCO, increased the tumor volume doubling time from 2.5 to 3.5 days (p less than 0.05). The acute exposure to carbon monoxide prior to and during irradiation significantly raised the radiation dose required to control the tumor locally. The TCD50 increased from 54 Gy in air breathing mice (HbCO 0-2%) to 57 Gy (HbCO 7-9%) and 61 Gy (HbCO 20-23%). This increase corresponded to an increase in the fraction of clonogenic hypoxic tumor cells from 0.12 in air breathing animals to 0.21 and 0.41, respectively. The tumor blood flow, determined by the 86RbCl extraction technique, decreased to 63% (n.s.) and 50% (p less than 0.05) for low and high HbCO levels, respectively.
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PMID:Influence of carboxyhemoglobin level on tumor growth, blood flow, and radiation response in an experimental model. 173 72


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