Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027947 (neutropenia)
 17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The hemolymphopoietic growth factors, including the colony-stimulating factors (CSF) and interleukins (IL), are described and categorized on the basis of their biological features in laboratory systems. Although these agents are varied and exceptions exist, in general they lack lineage specificity although they may express lineage-predominant activity. They act at multiple levels of hemolymphopoietic cell differentiation, demonstrate additive or synergistic effects when combined in vitro, require surface receptors on target cells to directly express their activity, and may be produced by a variety of cells. This framework of behavioral generalizations, completed by the specifics of each factor's activity, despite the artifactual and simplified nature of in vivo systems, forms the basis for concepts of in vitro activity and for clinical applications. Hemolymphopoietic growth factors studied in the clinic have demonstrated impressive and important activity, validating much of the in vitro data. Granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) have clearly reduced neutropenia and infection rates when administered following conventional chemotherapy and high-dose chemotherapy followed by autologous bone marrow transplantation. To a varying degree, similar results with G-CSF and/or GM-CSF have been described in other diseases including acute myelogenous leukemia (AML) treated following induction chemotherapy, myelodysplastic syndrome, hairy cell leukemia, aplastic anemia, and chronic neutropenias. In preliminary studies IL-3 has been shown to have similar qualitative activities. However, these agents have not demonstrated a reproducible salutary impact on platelet or red cell lineages. Adverse effects on platelet counts and/or platelet recovery have been noted. Additionally, hemolymphopoietic growth factor receptors have been identified on malignant cells, suggesting that these factors could stimulate neoplastic growth. Studies with GM-CSF and IL-3 have demonstrated blast proliferation in some cases of AML and myelodysplasia, underscoring the capacity of these agents to stimulate the growth of myeloid leukemia. No clinically evident impact of these factors upon the growth of solid tumors has been identified but this issue has not been adequately studied. The toxicity of these agents has been surprisingly limited and appears to be related to their biologic activities. Hemolymphopoietic growth factors as single agents have broad clinical applications in cytopenias. Several methods for enhancing the clinical activity of these agents are under study, including the use of combinations of growth factors synergistic in vitro.
 ...
PMID:Recombinant human hematopoietic growth factors in the treatment of cytopenias. 172 85

In order to improve survival in a disease where the majority of deaths occur from metastases, the integration of systemic chemotherapy is crucial. Research efforts must continue to focus on refining case selection criteria, improving complete response proportions, and overcoming drug resistance. The blanket recommendation of a single therapeutic strategy such as radical surgery, chemotherapy, or radiation therapy to all patients is quickly becoming an outdated approach. Refinements in the understanding of the clinical, pathologic, and molecular features of urothelial tumors will ultimately improve case selection. Evaluation of NM23 RNA levels, or DNA ploidy and T138 surface antigen expression, which have been shown to correlate with metastatic potential, may hold important therapeutic implications. The use of hematopoietic growth factors has the potential to improve both the tolerance of chemotherapy and complete response proportions, a prerequisite for cure. A recent report from Japan of granulocyte colony-stimulating factor with MVAC and other chemotherapy regimens for urothelial tumors corroborated an initial report in reducing the duration of neutropenia. However, the dose response curves for most of the known active agents are not well defined and, ultimately, new agents and strategies will be required. Gallium nitrate, when administered by continuous intravenous infusion, has significant single agent activity in cisplatin-refractory patients with 9/31 responses (29%), including 6 CRs (19%) and further studies are warranted. Drug resistance remains a major obstacle, and as the mechanisms are unravelled, more rational therapies can be designed. For example, resistance to Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH) and vinblastine, two components in the MVAC regimen, are mediated in part by the MDR1 gene. Attempts are ongoing to identify prospectively those tumors with high levels of expression that may be more amenable to treatment with drugs that are not affected by this mechanism. The neoadjuvant approach allows an in vivo assessment of response to chemotherapy as well as the potential for bladder preservation. In most cases additional therapy directed at the primary is required as clinical understaging is a significant problem and pCR proportions are less than 30%. For some patients, initial surgery followed by treatment based on pathologic criteria may represent a better strategy. In these cases the recommendation for adjuvant treatment potentially limits therapy to a population of patients for whom therapy is essential. Based on available data, this would include patients with positive lymph nodes at the time of surgery. Ideally, patients with invasive bladder cancer should be entered into clinical trials designed to assess the impact of these strategies on survival.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:The evolving role of chemotherapy for muscle infiltrating bladder cancer. 177 75

Since children with acute leukemia have prolonged periods of severe neutropenia due to the disease itself or its intensive chemotherapy, they often develop life-threatening infectious complications. A protected environment and prophylactic antibiotics for patients with severe neutropenia have been shown to decrease the incidence of infectious morbidity. In spite of the high mortality rate of infections, on the other hand, their diagnosis is not well established because the percentage of microbiological detectability by blood culture is low. The differentiation of infections may be possible by using some supplementary measures and particular laboratory parameters. Febrile neutropenic patients with leukemia should promptly receive empiric treatment with combinations of two or three broad-spectrum antibiotics that are bactericidal and synergistic toward the presumed pathogens, or with antifungal drugs if patients are resistant to antibiotics, as well as supportive measures such as granulocyte transfusion, intravenous gamma-globulin and granulocyte colony-stimulating factor.
 ...
PMID:Infectious complications in childhood leukemia. 179 17

A number of human hematopoietic growth factors have been genetically cloned and recombinant proteins produced. Several phase I and II clinical trials have already been published and results from phase III studies are becoming available. The use of erythropoietin to alleviate chemotherapy-induced myelosuppression is being tested. Granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor have been extensively studied in patients receiving chemotherapy at standard or escalated doses and after bone marrow transplantation and appear to ameliorate chemotherapy-induced neutropenia and to speed bone marrow engraftment after high-dose cancer therapy. Interleukin-3 and interleukin-6 are quite early in their clinical development, but appear able to alleviate post-chemotherapy thrombocytopenia.
 ...
PMID:Hematopoietic growth factors as supportive therapy for cancer- and chemotherapy-induced conditions. 193 23

A number of studies have illustrated the effectiveness of hematopoietic growth factors in managing treatment-related cytopenias in patients with human immunodeficiency virus (HIV) infection. One of these factors, granulocyte-macrophage colony-stimulating factor, has been shown to restore absolute neutrophil counts in patients with acquired immunodeficiency syndrome (AIDS) and Kaposi's sarcoma receiving a combination of zidovudine (AZT) and interferon alfa. A combination of granulocyte colony-stimulating factor and erythropoietin has also been demonstrated to alleviate both neutropenia and anemia in patients with advanced AIDS or AIDS-related complex receiving zidovudine. Hematopoietic growth factors, in combination with each other and with antiretroviral agents, thus have an important supportive role to play in the treatment of patients with HIV disease.
 ...
PMID:Antiretroviral therapy and immunomodulators in patients with AIDS. 201 46

The colony-stimulating factors (CSF) are a class of glycoprotein hormones that regulate the production and function of blood cells. Human sequences encoding four of the factors active on myeloid cells--granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF), macrophage colony-stimulating factor (M-CSF), and interleukin-3 (IL-3)--have been molecularly cloned and the biosynthetic (recombinant) products introduced into clinical trials. Sufficient clinical data have accumulated regarding G-CSF and GM-CSF to allow insight into their potential use in clinical practice. Both molecules have shown some impact in the prevention of chemotherapy-induced neutropenia and in the treatment of cytopenias associated with myelodysplastic syndromes and aplastic anemia. G-CSF has shown promise in the treatment of congenital and idiopathic neutropenias.
 ...
PMID:The colony-stimulating factors: biology and clinical use. 214 19

Recombinant human granulocyte colony-stimulating factor (G-CSF) has been shown to reduce neutropenia following cytotoxic therapy, thereby enabling dose escalation to improve the response rate. It is important to know whether drug kinetics change as doses are increased. Doxorubicin was selected because of its broad spectrum of activity and its known efficacy in metastatic breast cancer. Doses of 75, 100, 125 and 150 mg/m2 were given to 11 patients with metastatic breast cancer by infusion over 30 min. Serum concentrations of parent drug and metabolites were determined during the first 48 h following the infusion by high-performance liquid chromatography (HPLC). The serum concentration vs time curve decayed as a triple exponential function in four patients and as a double exponential function in seven. A four-compartment model, one central and three peripheral, would predict concentrations to within 1 SE of the observed values. Doxorubicinol was the principal metabolite, and doxorubicinone and 7-deoxydoxorubicinone were clearly identified. There was a linear increase in the AUC infinity with dose. In addition, a small and transient increase in circulating levels of doxorubicinol and other important metabolites was observed 6 h following the administration of doxorubicin, which suggests the existence of an enterohepatic, or other, re-circulation mechanism. We conclude that in the dose range selected the kinetics of doxorubicin are linear and that the increase in toxicities seen with the higher doses of doxorubicin, following the second and third fortnightly administration, may be due to intracellular drug accumulation in tissues.
 ...
PMID:Comparative pharmacokinetics of escalating doses of doxorubicin in patients with metastatic breast cancer. 231 Nov 72

A purified human granulocyte colony-stimulating factor (hG-CSF) was studied for its protective effect on the induction of neutropenia and enhanced susceptibility to microbial infections in mice receiving cyclophosphamide (CPA). A severe reduction in peripheral blood neutrophils was induced 4 days after injection with 200 mg of CPA per kg although the level normalized rapidly thereafter. When mice were injected subcutaneously once a day with 2.5 micrograms of hG-CSF beginning on the day after CPA injection, the reduction was prevented markedly, even 4 days later. On the other hand, in mice receiving CPA 4 days prior to infection, a weakened resistance to intraperitoneal challenge with a strain of Pseudomonas aeruginosa was induced. This weakened resistance was dose-dependently restored to normal by four daily injections with hG-CSF. A daily dose of 1.0 microgram was required for complete restoration, although hG-CSF did not directly inhibit bacterial growth in vitro. In hG-CSF-treated mice, morphologically mature neutrophils migrated rapidly into the peritoneal cavities where bacteria were inoculated, followed by a rapid elimination of bacteria from the locality as compared with controls. In addition, the same treatment with hG-CSF was able to protect significantly against systemic infections caused by Serratia marcescens, Escherichia coli, Staphylococcus aureus, and Candida albicans. These data show the possibility that prophylactic therapy with hG-CSF may augment the resistance of immunocompromised patients to infections.
 ...
PMID:Protective effect of human granulocyte colony-stimulating factor on microbial infection in neutropenic mice. 244 40

We evaluated the ability of human recombinant granulocyte colony-stimulating factor (rhG-CSF) to prevent chemotherapy-induced neutropenia or to accelerate recovery from this complication and thus allow patients to receive full doses of antineoplastic agents on time, according to protocol design. Twenty-seven patients with transitional-cell carcinoma of the urothelium who were undergoing treatment with methotrexate, doxorubicin, vinblastine, and cisplatin were given rhG-CSF (up to 60 micrograms per kilogram of body weight per day) before their first cycle of combination chemotherapy, during the first cycle, or at both points. Treatment with rhG-CSF before chemotherapy resulted in a dose-dependent increase in the absolute neutrophil count. Treatment with rhG-CSF after chemotherapy significantly reduced the number of days (91 percent) per patient on which the absolute neutrophil count was 1000 per microliter or less (P = 0.0039), reduced the number of days (1 vs. 35) on which antibiotics were used to treat fever and neutropenia, and significantly increased the percentage (100 vs. 29 percent) of patients qualified to receive planned chemotherapy on day 14 of the treatment cycle (P = 0.0015). In addition, the incidence of mucositis was significantly decreased (11 vs. 44 percent, P = 0.041), as was its severity. These findings demonstrate that rhG-CSF is a potent stimulus of normal neutrophil proliferation and maturation. In addition, its administration can reduce both the hematopoietic and oral toxicity of chemotherapy.
 ...
PMID:Effect of granulocyte colony-stimulating factor on neutropenia and associated morbidity due to chemotherapy for transitional-cell carcinoma of the urothelium. 245 83

Canine cyclic hematopoiesis (CH) is an autosomal recessive disease of gray collie dogs that is characterized by neutropenic episodes at 14-day intervals. The biochemical basis for CH is not known but may involve a regulatory defect of the response to or production of a hematopoietic growth factor. Administration of recombinant human granulocyte colony-stimulating factor (rhG-CSF) to two CH and one normal dog caused a marked leukocytosis (greater than 50,000 WBCs) in all three dogs. The leukocytosis was due largely to a greater than tenfold increase in neutrophils. Less pronounced but significant elevations in monocytes occurred during G-CSF treatment. The elevated WBC count was maintained for more than 20 days in all three dogs, and two predicted neutropenic episodes were prevented in both CH dogs during rhG-CSF treatment. A decline in the WBC count occurred simultaneously in all three dogs during the last five treatment days and was presumably associated with the development of neutralizing antibodies to the heterologous rhG-CSF protein. Bone marrow evaluation indicated that the swings in the myeloid/erythroid progenitor cells that are characteristic of CH were eliminated by rhG-CSF treatment in both CH dogs. These results suggest that the regulatory defect in canine CH can be temporarily alleviated by treatment with rhG-CSF and point to the potential treatment of human cyclic neutropenia with this agent.
 ...
PMID:Correction of canine cyclic hematopoiesis with recombinant human granulocyte colony-stimulating factor. 245 81


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>