Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gallium, when bound to transferrin, has been previously shown to cause tumor cell cytotoxicity by preventing cellular uptake of transferrin bound iron in vitro. Patients treated with constant infusion gallium nitrate for carcinoma show a rise in serum iron within 6 hr of the start of treatment. Serum iron returns to baseline by 24 hr post-infusion. Atomic analysis of iron and gallium content of Sephadex G-150 fractions of treatment sera indicate that about an equimolar amount of gallium and iron are associated with transferrin. These gallium and iron concentrations result in inhibition of transferrin mediated iron uptake in vitro, and in vivo allow for > 90% saturation of transferrin with metal. All seven patients who completed two courses of gallium therapy exhibited hypochromic microcytic anemia (mean fall in hemoglobin 3.5 grams %). Evidence for red cell iron depletion was confirmed by an increase (mean 3.3-fold) in zinc protoporphyrin levels. Since transferrin receptor increases on gallium treated iron requiring cells in vitro, we assessed cell surface transferrin receptor on peripheral blood lymphocytes by measuring fluorescent transferrin receptor antibody binding. A population of highly transferrin receptor positive cells peaks at 48 hr into the infusion. DNA analysis as well as double staining indicate the majority of transferrin receptor positive cells are unstimulated B lymphocytes. These studies provide the first documentation that constant infusion gallium treatment results in significant interference with iron metabolism and evidence for tissue iron depletion in vivo. These changes may correlate with therapeutic effects of gallium such as tumor response.
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PMID:Treatment with gallium nitrate: evidence for interference with iron metabolism in vivo. 133 63

This article reviews the pathophysiologic concept that superoxide and hydrogen peroxide, generated by activated leukocytes, together with low-molecular-weight chelate iron derived from fecal sources and from denatured hemoglobin, amplify the inflammatory response and subsequent mucosal damage in patients with active episodes of ulcerative colitis. The putative pathogenic mechanisms reviewed are as follows: (1) Dietary iron is concentrated in fecal material owing to normally limited iron absorption. (2) Mucosal bleeding, characteristic of ulcerative colitis, as well as supplemental oral iron therapy for chronic anemia, further conspire to maintain or elevate mucosal iron concentration in colitis. (3) Fenton chemistry, driven especially by leukocyte-generated superoxide and hydrogen peroxide, leads to formation of hydroxyl radicals. (4) The resultant oxidative stress leads to the extension and propagation of crypt abscesses, either through direct membrane disruption by lipid peroxidation or through generation of secondary toxic oxidants such as chloramines. (5) Chemotactic products of lipid peroxidation, including 4-hydroxynonenal, provide positive feedback to accelerate this inflammatory/oxidative process, leading to acute exacerbations of the disease. (6) Other oxidized products, such as oxidized tryptophan metabolites, created by free radical mechanisms in or near the mucosa, may act as carcinogens or tumor promotors that contribute to the exceedingly high incidence of colon carcinoma in patients suffering from chronic ulcerative colitis. In this way, self-sustaining cycles of oxidant formation may amplify flare-ups of inflammation and mucosal injury in ulcerative colitis. This concept, if proved correct by subsequent research, would provide a rationale for several novel clinical approaches to the management of ulcerative colitis, including use of SOD mimetics, iron chelators, and chain-breaking antioxidants.
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PMID:Oxygen radicals in ulcerative colitis. 135 59

Human monocyte-derived macrophages ingest diamide-treated red blood cells (RBC), anti-D immunoglobulin (Ig)G-opsonized RBC, or Plasmodium falciparum ring-stage parasitized RBC (RPRBC), degrade ingested hemoglobin rapidly, and can repeat the phagocytic cycle. Monocytes fed with trophozoite-parasitized RBC (TPRBC), which contain malarial pigment, or fed with isolated pigment are virtually unable to degrade the ingested material and to repeat the phagocytic cycle. Monocytes fed with pigment display a long-lasting oxidative burst that does not occur when they phagocytose diamide-treated RBC or RPRBC. The phorbol myristate acetate-elicited oxidative burst is irreversibly suppressed in monocytes fed with TPRBC or pigment, but not in monocytes fed with diamide-treated or IgG-opsonized RBC. This pattern of inhibition of phagocytosis and oxidative burst suggests that malarial pigment is responsible for the toxic effects. Pigment iron released in the monocyte phagolysosome may be the responsible element. 3% of total pigment iron is labile and easily detached under conditions simulating the internal environment of the phagolysosome, i.e., pH 5.5 and 10 microM H2O2. Iron liberated from pigment could account for the lipid peroxidation and increased production of malondialdehyde observed in monocytes fed with pigment or in RBC ghosts and liposomes incubated at pH 6.5 in presence of pigment and low amounts of H2O2. Removal of the labile iron fraction from pigment by repeated treatments with 0.1 mM H2O2 at pH 5.5 reduces pigment toxicity. It is suggested that iron released from ingested pigment is responsible for the intoxication of monocytes. In acute and chronic falciparum infections, circulating and tissue-resident phagocytes are seen filled with TPRBC and pigment particles over long periods of time. Moreover, human monocytes previously fed with TPRBC are unable to neutralize pathogenic bacteria, fungi, and tumor cells, and macrophage responses decline during the course of human and animal malaria. The present results may offer a mechanistic explanation for depression of cellular immunity in malaria.
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PMID:Impairment of macrophage functions after ingestion of Plasmodium falciparum-infected erythrocytes or isolated malarial pigment. 140 49

The clinic-epidemiologic and prognostic features of 424 cases of Ewing sarcoma observed at "Rizzoli" Institute between 1972-1990 are reported. The incidence of the tumor was higher in the second decade of life with slight predominance in the male sex. The primary lesion was especially localized in the extremity and the ratio lower/upper extremity was 5/1. We did not find, in contrast with other Authors, differences in height or in incidence of congenital malformations when compared to controls. The pain was the first common symptom at debut (90%) followed by swelling (50%) and fever (40%). Diagnosis was made 5.5 months after the first symptom and the delay was due to wrong diagnosis at debut in 3/4 of the patients. Laboratory tests showed anemia in about half of the patients and increased value of ESR (60%) and LDH (40%). Seventy-one of the patients were metastatic at presentation, none of these patients were still living after three years. At a median follow-up of 9 years 43% of the patients with localized disease, treated with adjuvant and neo-adjuvant chemotherapy remained continuously disease free, 53% developed metastatic disease and/or local recurrences and 2% had a second malignancy. In 24% of the patients metastases and/or local recurrences appeared three years after the beginning of treatment. Better prognosis was observed in female patients, without fever at diagnosis, with tumor localized at extremities and with normal value of hemoglobin, ERS and LDH. Regarding the type of treatment, better results were obtained by surgery of the primary tumor and by chemotherapy with four drugs (vincristine, cyclophosphamide, adriamycin dactinomycin) in comparison to radiotherapy of the primary tumor and chemotherapy with three drugs (vincristine, cyclophosphamide, adriamycin).
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PMID:[Ewing's sarcoma of the bone. Anatomoclinical study of 424 cases]. 140 9

Flunarizine is a diphenylpiperazine calcium entry blocker that has been shown previously to increase tumor blood flow and sensitivity to radiotherapy via reduction in the radiobiologically significant hypoxic fraction. Two mechanisms of action have been proposed previously (vasodilation, altered blood viscosity), but no studies have been performed to examine its mechanisms of action in vivo. Such information would be invaluable in determining the role of flunarizine in multimodality approaches to reduce tumor hypoxia. Fisher-344 rats bearing R3230Ac tumors transplanted into dorsal flap window chambers were used to examine microcirculatory changes after administration of flunarizine (1.0 mg/kg, iv). The drug increased the diameters of the microvasculature and red cell velocities specifically in central tumor regions (producing an average increase in vessel flow by a factor of 1.96), which was accompanied by an increase in perivascular pO2 of 12 mm Hg, on the average. The drug did not change the diameters of tumor "feeding" vessels, nor did it change vascular length densities. Thus the improvement in central tumor blood flow and oxygenation could not be attributed to dilation of feeding vessels. The oxygen-carrying capacity of the blood was not altered either since hemoglobin saturation (measured in vitro) and the hematocrits of the microvasculature were unchanged after drug administration. Therefore, by a process of elimination, the most likely explanation for the effect of the drug is modification of blood viscosity. Additional studies are under way in this laboratory to examine whether changes in viscosity occur after flunarizine administration.
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PMID:Effects of the calcium channel blocker flunarizine on the hemodynamics and oxygenation of tumor microvasculature. 141 Feb 75

A 42-year-old male was diagnosed as having Ph-positive chronic myelogenous leukemia (CML) in 1988. He had been treated with ranimustine and interferon alpha. In April 1990, he was admitted to our hospital because of hemorrhagic diathesis. Blood counts revealed a white blood cell count of 319,200/microliters with 12 per cent blasts, a hemoglobin level of 9.2 g/dl, and a platelet count of 48,000/microliters. The bone marrow aspiration revealed hypercellularity with 68.2 per cent blasts, and chromosomal analysis showed 48, XY, +8, double Ph. A combination chemotherapy containing vindesine, cytarabine and prednisolone was administered. Four days later, he suddenly complained of headache and vertigo. CT scan of the brain showed a high density area at the cerebellar vermis. He was then treated with intensive combination chemotherapy including enocitabine, daunomycin, 6-mercaptopurine and prednisolone. He attained a hematological response and clinical improvement temporarily, as the cerebellar tumor regressed. In September he had headache and vertigo again, and CT scan revealed a rapid increase in size of the cerebellar tumor. Local irradiation with total doses of 19 Gy brought about a partial resolution of the lesion, and relief from the symptoms. In November, his hematological conditions deteriorated gradually and he died of brain hemorrhage on November 22, 1990. Post-mortem examination disclosed a 1 x 1 cm sized mass in the cerebellar vermis which showed a fibrous change surrounded with hemosiderin-laden macrophages microscopically. We reviewed the eight reported cases of CML with intracranial tumors, and discussed the factors which had contributed to the prolongation of survival in our patient.
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PMID:[Isolated cerebellar tumor formation in a patient with blastic crisis of chronic myelogenous leukemia]. 143 48

Friend erythroleukemia cells (FELCs) differentiate after hexamethylene-bis-acetamide treatment. This differentiation is characterized by an increase in beta-globin gene expression that is followed by appearance of the hemoglobin. Phorbol-ester tumor promoters, such as 12-O-tetradecanoylphorbol-13-acetate (TPA), inhibit differentiation of TPA-sensitive cells but not TPA-resistant cells. We have shown that the increase in beta-globin expression is inhibited by TPA in a TPA-sensitive clone but not in a TPA-resistant clone. To study the molecular mechanisms of regulation of gene expression by TPA, we examined the possible involvement of gene methylation and the TPA-responsive element (TRE). Both clones showed similar patterns of methylation around the beta-globin gene. Moreover, TPA-induced TRE binding and TRE enhancer activity were similar in both variants. These results suggest that the TPA inhibition of induced differentiation may not be explained by regulation of the methylation state. The activator protein-1 also does not play a crucial role in the sensitivity of FELCs to TPA.
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PMID:Role of activator protein-1 and methylation function in 12-O-tetradecanoylphorbol-13-acetate--mediated inhibition of differentiation of Friend erythroleukemia cells. 144 21

To evaluate the efficacy of intraperitoneal (IP) carboplatin-based therapy as salvage treatment of ovarian cancer, 46 patients with persistent or recurrent ovarian cancer following initial systemic chemotherapy were treated with a regimen of carboplatin (200-300 mg/m2) and etoposide (100 mg/m2) administered on a monthly schedule. A maximum of six courses of therapy was delivered, followed by a response laparotomy. The treatment program was well tolerated, except for bone marrow suppression, with one-quarter of patients developing platelet count depressions to < or = 50,000/mm3, and one-third experiencing hemoglobin levels of < or = 8 g/dl during treatment. Twelve (38%) of 32 patients evaluable for efficacy of the treatment program achieved a surgically documented response, including 8 (25%) complete responses. Of 25 patients whose largest tumor mass at the initiation of therapy measured < or = 0.5 cm, 11 (44%) responded, including 8 (32%) complete responses. We conclude that the IP administration of carboplatin can result in surgically documented responses when used in the salvage setting in patients with advanced ovarian cancer. The relative efficacy of carboplatin versus cisplatin when administered by the IP route to patients with ovarian cancer previously treated with platinum-based systemic therapy remains to be defined.
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PMID:Phase 2 trial of intraperitoneal carboplatin and etoposide as salvage treatment of advanced epithelial ovarian cancer. 147 49

Heterogeneity of response of tumor tissue to radiation clearly exists. Major parameters include histopathologic type, size (number of tumor rescue units (TRUs)), hemoglobin concentration, cell proliferation kinetics and immune rejection reaction by host. Further, normal and presumably tumor tissue response is altered in certain genetic diseases, e.g. ataxia telangiectasia. Any assessment of response of tumor tissue to a new treatment method or the testing of a new clinical response predictor is optimally based upon a narrow strata, viz., uniform with respect to known parameters of response, e.g. size, histological type. Even among tumors of such a clinically defined narrow strata, there will be residual heterogeneity with respect to inherent cellular radiation sensitivity, distributions of pO2, (SH), cell proliferation etc. The value of a response predictor of an individual tumor will be determined by the heterogeneity of values for these and or other characteristics and by the coefficient of variation (CV) of the measured values of the individual parameters. Heterogeneity of one or more parameters of response is reflected in the slope of the dose response curve for local control, viz. the greater the heterogeneity the less steep the slope. To examine for this effect, the slope of dose response curves for control of model tumors of 10(8) tumor rescue units (TRU) and the SF2 = 0.5 (survival fraction after a single dose of 2 Gy) has been used to assess the impact of inter- and intra-tumoral variation of SF2 on slope, defined as gamma 50 values. The gamma 50 is the increase in local control expressed in percent points for a one percentage increment in dose, at the mid-point on the dose-response curve. The gamma 50 was 6.5 for CV = 0.0. For inter-tumoral CVs of 10%, 20% and 40%, the gamma 50 rapidly decreased to 2.4, 1.3 and 0.7. Intra-tumoral variation was less important, viz., for CVs of 10%, 20%, and 40% the gamma 50 values were reduced to 5.3, 3.8 and 2.2. Combining inter- and intra-tumoral variation reduced the gamma 50 only slightly below that for inter-tumoral variation alone. For example, were the CV 10% for inter- and intra-tumoral variation, the gamma 50 would be 2.1 as compared to 2.4 for inter-tumoral variation alone. The number of TRUs also affects slope, viz. gamma 50 increased from 1 to 9.7 as the TRU number increased from 10(1) to 10(12).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Clinical implications of heterogeneity of tumor response to radiation therapy. 148 Jul 70

Localized plasma cell type Castleman's disease (CD) is an unusual pathologic entity. It is frequently associated with clinical and laboratory characteristics and rarely occurs in children. Total surgical excision results in cure in all aspects. To make early diagnosis of mesenteric CD is not easy, especially for children. An 11-year-old Taiwanese boy was recently evaluated for anemia and delayed growth. His clinical findings included a syndrome of severe hypochromic microcytic anemia, neutropenia, thrombocytosis, hypoferremia, hypergammaglobulinemia, and growth failure. Radiological examinations (abdominal ultrasound, small intestinal series, and computerized tomography) identified hepatosplenomegaly, nephromegaly, and huge masses in the middle abdomen with precaval, celiac, and paraaortic lymph nodal enlargement. However, detailed physical examination failed to detect a mass. At laparotomy a double-fist-sized confluent mass was found arising from the mesenteric root. Most masses were discrete and were excised individually. The pathologic diagnosis was plasma-cell type angiofollicular lymph node hyperplasia (Castleman's disease). Seven weeks after surgery, he had an episode of acute hepatitis B. Postoperatively, he exhibited a dramatic growth spurt; the hemoglobin, red blood cell indices, serum iron, and immunoglobulins returned to normal in 2 months. Neutropenia, which has not been previously related to mesenteric CD, was an unexpected finding in our case; however, it resolved spontaneously 3 months after the surgery, suggesting its causal relationship with the tumor.
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PMID:New observations in a child with angiofollicular lymph node hyperplasia (Castleman's disease) originated from the mesenteric root. 151 Jan 96


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