Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023467 (acute myeloid leukemia)
 35,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acute panmyelosis with myelofibrosis (APMF) is an ill-defined disorder that may either evolve as a clonal hematopoietic condition or as a sequel of toxic exposure to the bone marrow (BM). Therefore, controversy and discussion continues as to whether APMF may be considered as a hyperfibrotic (de novo) myelodysplastic syndrome (MDS), as acute myeloid leukemia (AML) or as a severe toxic myelopathy with accompanying myelofibrosis. In this context scant knowledge exists about BM findings, but especially evolution of this disorder according to sequential examinations. Clinically patients present with pancytopenia, a very few blasts in the peripheral blood and no or little splenomegaly. Initially BM histopathology is characterized by different degrees of reticulin-collagen fibrosis and wide ranges of cellularity with a prominent left-shifted and often macrocytic erythropoiesis associated with a reduction and maturation defects of the neutrophil series. Most conspicuous are abnormalities of the megakaryocytes including loose clustering, dislocation towards the endosteal border and appearance of atypical microforms with compact nuclei. Moreover, besides myelofibrosis in a number of patients the interstitial compartment displays a remarkable inflammatory reaction with lymphoid nodules, abundant iron-laden macrophages, perivascular plasmacytosis and increase in microvessels. Repeatedly performed BM biopsies reveal an accumulation of dispersed or clustered CD34+ and lysozyme-expressing blasts in keeping with the insidious transformation into acute leukemia. Prognosis is unfavorable with a median survival of less than 1 year. In conclusion, APMF has to be regarded as a condition that shows considerable overlappings with primary hyperfibrotic MDS, AML and toxic myelopathy (secondary MDS) with accompanying myelofibrosis and therefore can not be considered as a definite clinical entity.
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PMID:Acute panmyelosis with myelofibrosis. 1516 Sep 39

Controversy continues whether acute panmyelosis with myelofibrosis (APMF) exists as a well-defined clinicopathological entity. Following exclusion of overt acute myeloid leukemia (AML), especially the megakaryoblastic subtype, a retrospective study was performed on 46 patients with clinical and morphological features suggesting the diagnosis of APMF. All patients had a bone marrow (BM) biopsy performed at onset, and 13 had follow-up examinations. Enzyme histochemical and immunohistochemical techniques were applied and BM features evaluated by a semiquantitative scoring system. Clinical findings consisted of pancytopenia associated with a left-shifted differential count of the peripheral blood (less than 5% blasts) and no or minor splenomegaly. During follow-up (median survival 9 months) 35 patients developed severe BM insufficiency and 10 transformed into overt AML. Although myelofibrosis was a characteristic finding, other BM features proved to be heterogeneous. Cellularity was reduced in 13 and increased in 25 specimens. Most prominent was a left-shifted, often macrocytic erythropoiesis and a maturation defect of the neutrophil series. In 15 patients an increase (less than 20%) in CD34+ progenitors, immature myelomonocytic cells, and megakaryoblasts was noted. Abnormalities of megakaryocytes (atypical microforms, clustering, dysplasia) were regularly present. The stroma showed an inflammatory reaction (perivascular plasmacytosis, lymphoid nodules, many macrophages, iron deposits) in about 50% of the samples. Sequential BM biopsies revealed an accumulation of lysozyme-expressing myelomonocytic and CD34+ progenitor cells suggesting an increase in blasts. In conclusion, APMF may not be a distinct entity, but includes hyperfibrotic myelodysplastic syndromes (MDS) either primary or secondary, a rare form of initial AML with fibrosis, and even cases of toxic myelopathy.
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PMID:Acute panmyelosis with myelofibrosis: a clinicopathological study on 46 patients including histochemistry of bone marrow biopsies and follow-up. 1517 58

We evaluated the frequency and prognostic significance of extramedullary infiltrates (EMI) at presentation of acute myeloid leukemia (AML) in adult patients. Of 331 cases with de novo AML, 101(30.5%) had extramedullary infiltrates at diagnosis. The extramedullary manifestations included: lymphadenopathy, splenomegaly, hepatomegaly, gingival hypertrophy, skin infiltrates and involvement of central nervous system (CNS). Patients with EMI had a high initial WBC count and a high proportion of M4/M5 morphological variants. The complete remission rate (CR) with induction chemotherapy was lower in patients with EMI (P=0.0077) and their overall survival was also inferior (P=0.0017). Flow cytometric evaluation of the surface antigens expressed by the leukemic blasts for CD34, TdT, HLADR, CD7, CD19 and CD56 found that only CD56 expression was associated with EMI. The association of CD56 expression with lymphadenopathy was statistically significant (P=0.035). Abnormal karyotypes were found in 50.6% of patients with EMI and 49.7% of patients without EMI. Only 11q23 abnormalities were associated with specific sites of EMI; lymphadenopathy (P=0.0111) and gingival hypertrophy (P=0.0016). Our study of adult AML patients demonstrates that EMI at diagnosis is associated with CD56 expression by leukemic blasts, 11q23 karyotypic abnormalities, low complete remission rate and poor overall survival.
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PMID:Extramedullary infiltrates of AML are associated with CD56 expression, 11q23 abnormalities and inferior clinical outcome. 1528 11

A 43 year-old woman presented with fever, abdominal pain, epato-splenomegaly, ascites, cholestasis, anemia, thrombocytopenia and previous diagnosis of sclerosing cholangitis based on liver biopsy and endoscopic retrograde cholangiopancreatography(ERCP). The bone marrow biopsy and the revision of liver biopsy using antitryptase stain diagnosed systemic mastocytosis. Because of the aggressive course of the disease the patient was treated with an acute myeloid leukaemia chemotherapy regimen without success.
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PMID:Aggressive systemic mastocytosis mimicking sclerosing cholangitis. 1537 87

Activating FMS-like tyrosine kinase 3 (FLT3) mutations have been identified in approximately 30% of patients with acute myelogenous leukemia (AML), and recently in a smaller subset of patients with acute lymphoblastic leukemia (ALL). To explore the in vivo consequences of an activating FLT3 internal tandem duplication mutation (FLT3-ITD), we created a transgenic mouse model in which FLT3-ITD was expressed under the control of the vav hematopoietic promoter. Five independent lines of vav-FLT3-ITD transgenic mice developed a myeloproliferative disease with high penetrance and a disease latency of 6-12 months. The phenotype was characterized by splenomegaly, megakaryocytic hyperplasia, and marked thrombocythemia, but without leukocytosis, polycythemia, or marrow fibrosis, displaying features reminiscent of the human disease essential thrombocythemia (ET). Clonal immature B- or T-lymphoid disease was observed in two additional founder mice, respectively, that could be secondarily transplanted to recipient mice that rapidly developed lymphoid disease. Treatment of these mice with the FLT3 tyrosine kinase inhibitor, PKC412, resulted in suppression of disease and a statistically significant prolongation of survival. These results demonstrate that FLT3-ITD is capable of inducing myeloproliferative as well as lymphoid disease, and indicate that small-molecule tyrosine kinase inhibitors may be an effective treatment for lymphoid malignancies in humans that are associated with activating mutations in FLT3.
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PMID:FLT3 internal tandem duplication mutations induce myeloproliferative or lymphoid disease in a transgenic mouse model. 1611 83

Groups of six BALB/c mice each were intravenously inoculated with lethal doses of Ba-P210 (B210) or 12B1 cells and examined by autopsy, histology, special staining methods, enzyme histochemistry and immunohistochemistry. Clinical symptoms related to neoplasia consisted of a poor nutritional state, anaemia, mild to moderate dehydration and apathy. Paresis was apparent in three mice inoculated with 12B1 cells. Necropsy revealed splenomegaly in all animals. Sporadic haemorrhages in the lungs and enlargement of some lymph nodes were seen in some of the animals. Histological examination showed neoplastic cells in the spleen, in the bone marrow of the sternum, in the lung interstitium and in sinusoids of the liver in all mice. In six of nine brains examined, mild to moderate infiltration by neoplastic cells was observed. In all but two mice mild infiltration of the kidneys was found. The enlargement of lymph nodes was caused by an accumulation of neoplastic cells. The paresis was due to neoplastic infiltration of the vertebra, epidural space and spinal roots. Staining with Sudan black revealed cytoplasmic granules in neoplastic cells; however, the peroxidase reaction was negative. Numerous neoplastic cells disseminated in the red pulp of the spleen were reactive with CD3, CD79beta, CD11b and with neutrophil antibodies. We classified the disease induced by both of the cell lines as acute myeloid undifferentiated leukaemia (AML MO).
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PMID:Characteristics of two mouse bcr-abl-transformed cell lines. II. Pathological lesions induced in mice. 1618 May 44

AML1 (RUNX1) encodes a DNA-binding subunit of the CBF transcription factor family and is required for the establishment of definitive hematopoiesis. AML1 is one of the most frequently mutated genes associated with human acute leukemia, suggesting that genetic alterations of the gene contribute to leukemogenesis. Here, we report the analysis of mice carrying conditional AML1 knockout alleles that were inactivated using the Cre/loxP system. AML1 was deleted in adult mice by inducing Cre activity to replicate AML1 deletions found in human MDS, familial platelet disorder and rare de novo human AML. At a latency of 2 months after induction, the thymus was reduced in size and frequently populated by immature double negative thymocytes, indicating defective T-lymphocyte maturation, resulting in lymphatic diseases with 50% penetrance, including atypical hyperplasia and thymic lymphoma. Metastatic lymphomas to the liver and the meninges were observed. Mice also developed splenomegaly with an expansion of the myeloid compartment. Increased Howell-Jolly body counts indicated splenic hypofunction. Thrombocytopenia occurred due to immaturity of mini-megakaryocytes in the bone marrow. Together with mild lymphocytopenia in the peripheral blood and increased fractions of immature cells in the bone marrow, AML1 deficient mice display features of a myelodysplastic syndrome, suggesting a preleukemic state.
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PMID:AML1 deletion in adult mice causes splenomegaly and lymphomas. 1624 65

Severe congenital neutropenia (CN) includes a variety of hematologic disorders characterized by severe neutropenia, with absolute neutrophil counts (ANC) below 0.5 x 10(9)/L, and associated with severe systemic bacterial infections from early infancy. One subtype of CN, Kostmann syndrome, is an autosomal recessive disorder, characterized histopathologically by early-stage maturation arrest of myeloid differentiation. CN with similar clinical features occurs as an autosomal dominant disorder and many sporadic cases also have been reported. This genetic heterogeneity suggests that several pathophysiological mechanisms may lead to this common clinical phenotype. Recent studies on the genetic bases of CN have detected inherited or spontaneous point mutations in the neutrophil elastase gene (ELA 2) in about 60% to 80% of patients and, less commonly, mutations in other genes. Acquisition of additional genetic defects during the course of the disease, for example, granulocyte colony-stimulating factor (G-CSF) receptor gene mutations and cytogenetic aberrations, indicates an underlying genetic instability as a common feature for all congenital neutropenia subtypes. Data on more than 600 patients with CN collected by the Severe Chronic Neutropenia International Registry (SCNIR) demonstrate that, regardless of the particular CN subtype, more than 95% of these patients respond to recombinant human (rHu)G-CSF with ANCs that can be maintained above 1.0 x 10(9)/L. Adverse events include mild splenomegaly, osteoporosis, and malignant transformation into myelodysplasia (MDS)/leukemia. If and how G-CSF treatment impacts on these adverse events is not fully understood. In recent analyses the influence of the G-CSF dose required to achieve neutrophil response (ANC >1,000/microL) in the risk of developing acute myeloid leukemia (AML) has been reported. Hematopoietic stem cell transplantation (HSCT) is still the only treatment available for patients who are refractory to G-CSF treatment.
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PMID:Severe congenital neutropenia. 1682 61

Acute myeloid leukemia (AML) with recurrent genetic abnormalities often carries a favorable prognosis. AML with inv(16)(p13q22) occurs predominantly in younger patients and usually shows granulocytic and monocytic differentiation with abnormal eosinophils. It is referred to as acute myelomonocytic leukemia with abnormal eosinophils (AMML Eo). We report a case in a 27-year-old man with leukocytosis (10.6 x 10(3)/microL with 34% blasts), thrombocytopenia and splenomegaly. Marrow aspiration showed 47% blasts and 33% eosinophils, of which 19% were morphologically abnormal with both eosinophilic and basophilic cytoplasmic granules. Cytochemically, the blasts were positive for myeloperoxidase while the granules of abnormal eosinophils were positive for naphthol ASD chloroacetate esterase. With flow cytometric immunophenotyping the blasts expressed CD13, CD33, CD117, myeloperoxidase and CD34. Marrow trephine showed 90% cellularity with 40% blasts expressing CD34, CD117, and myeloperoxidase on immunohistochemistry. Chromosomal analysis reveled a karyotype of 46, XY, inv(16)(p13q22). This case illustrates a typical AMML Eo confirmed by a multi-modality diagnostic approach including morphology, cytochemistry, flow cytometry, immunohistochemistry, and conventional cytogenetic study.
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PMID:Acute myelomonocytic leukemia with abnormal eosinophils: a case report with multi-modality diagnostic work-up. 1721

Evidence is continuing to accumulate that the FMS-like tyrosine kinase 3 (FLT3) receptor plays an important role in acute leukemias. Acute myeloid leukemia patients often express constitutive active mutant forms of the receptor in their leukemic cells. A t(12;13)(p13;q12) translocation between Tel and the FLT3 receptor was recently described in a patient with myeloproliferative disease (MPD). Here a Tel-FLT3 construct mimicking this fusion protein was used to generate transgenic mice. The fusion protein was previously found to constitutively activate FLT3 signaling and transform Ba/F3 cells. Expression of the fusion protein in the transgenic mice was found in all tissues assayed including spleen, bone marrow (BM), thymus and liver. These mice developed splenomegaly and had a high incidence of MPD with extramedullary hematopoiesis in the liver and lymph nodes. Spleens also had increased dendritic and natural killer cell populations. In vitro analysis of the hematopoietic progenitor cells derived from Tel-FLT3 transgenic mice showed a significant increase in the number of CFU-GM in the BM, and CFU-GM, BFU-E and CFU-GEMM in the spleen. BM also showed significant increases of in vivo CFU-S colonies. Thus, transgenic mice expressing constitutively activated Tel-FLT3 develop MPD with a long latency and also result in the expansion of the hematopoietic stem/progenitor cells.
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PMID:Transgenic mice expressing Tel-FLT3, a constitutively activated form of FLT3, develop myeloproliferative disease. 1726 28


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