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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The phenomenon of premature chromosome condensation (PCC) was used to compare the bone marrow proliferation characteristics of 163 patients with various forms of leukemia prior to the initiation of new therapy. The proliferative potential index (PPI, or fraction of G1 cells in late G1 phase) and the fraction of cells in S phase was determined and compared to the type of disease and the bone marrow blast infiltrate for each patient. Previously untreated patients with acute leukemia exhibited an average PPI value three times that of normal bone marrow (37.5% for acute myeloblastic leukemia [AML], acute monomyeloblastic leukemia [AMML], or acute promyelocytic leukemia [APML] and 42% for acute lymphocytic leukemia [ALL] or acute undifferentiated leukemia [AUL]). Untreated chronic myelogenous leukemia (CML) patients showed intermediate PPI values (25.2%), whereas CML patients with controlled disease exhibited nearly normal PPI values (14.6%). On the other hand, blastic-phase CML patients exhibited PPI values closer to that observed in patients with acute leukemia (35.4%). Seven patients with chronic lymphocytic leukemia (CLL) exhibited even higher PPI values. No correlations were observed between PPI values, fraction of cells in S phase, and marrow blast infiltrate. For untreated acute disease patients, PPI values were prognostic for response only at low and high PPI values. These results suggest that the PCC-determined proliferative potential is a biologic reflection of the degree of malignancy within the bone marrow.
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PMID:Premature chromosome condensation studies in human leukemia. I. Pretreatment characteristics. 29 41

A study of granulocyte function in myeloblastic leukaemia is reported. Function was assessed by the ability of peripheral blood granulocytes to ingest and kill Candida albicans in bitro. Depressed cidal activity was observed in 11 patients with smouldering leukaemia and in 19 patients with acute myeloid leukaemia. Cidal activity was lowest in the untreated acute disease; this improved during cytoreduction therapy and was maintained when remission occurred. Leukaemic plasma depressed the function of control granulocytes; the possible role of a plasma "factor" is discussed.
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PMID:Granulocyte function in myeloblastic leukaemia. 76 49

The natural history and haematological features of 18 patients with a chronic form of myelomonocytic leukaemia are described. The majority were elderly and, in this series, females predominated. Haematological prodomata, such as unexplained monocytosis, leucopenia, or thrombocytopenia were common, and the clinical onset was insidious. Splenomegaly was variable but tended to increase as the disease progressed. Anaemia was usually less than in the acute disease, unless compounded by iron deficiency. The blood film typically showed a mixed monocytosis and granulocytosis, cells in both lines showing abnormalities. 'Paramyeloid' cells, appearing in Romanowsky stained films intermediate between myelocytes and monocytes, were characteristic, although cytochemical and electron microscopical analysis suggests that these cells may be allotted to one or other cell line. The marrow aspirate was characteristically hypercellular, showed granulocytic hyperplasia, and, in contrast to the well-differentiated blood picture, the proportion of poorly differentiated cells, including blasts, was high. Serum lysozyme levels were usually raised. Five of the 18 cases survived more than 5 years, while 10 lived 2 years or longer. The morphological and clinical features form part of a spectrum including acute myelomonocytic leukaemia, into which several of the patients transformed. Recognition of the syndrome is important because the patients are probably best managed without intensive chemotherapy.
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PMID:Chronic myelomonocytic leukaemia. 105 74

Mice infected with LP-BM5 murine leukemia viruses develop a syndrome, termed mouse AIDS (MAIDS), characterized by increasingly severe immunodeficiency and progressive lymphoproliferation. Virus-infected mice were examined for the ability to resist acute infection and to control chronic infection with the protozoan Toxoplasma gondii, a major opportunistic pathogen of individuals infected with human immunodeficiency virus. Mice infected with the retroviruses for 2 or 4 weeks responded normally to challenge with the parasite, but mice inoculated with the protozoan 8 or 12 weeks after viral infection died with acute disease due to T. gondii. Increased sensitivity to acute infection was associated with a reduced ability to produce gamma interferon (IFN-gamma) and with established changes in CD4+ T-cell function. Mice latently infected with T. gondii and then inoculated with the retrovirus mixture were found to reactivate the parasite infection, with 30 to 40% of dually infected animals dying between 5 and 16 weeks after viral infection. Reactivation was associated with reduced proliferation and impaired production of IFN-gamma in response to stimulation with soluble T. gondii antigens or to concanavalin A. Continuing resistance to lethal reactivation in the remaining mice was shown to require CD8+ T cells and expression of IFN-gamma. In addition, it was found that chronic infection with T. gondii altered the course of MAIDS by inhibiting the progression of splenomegaly and immunodeficiency and reducing the expression of both the helper and etiologic defective viruses. These results support previous studies which indicate that infection with T. gondii is controlled by synergistic interactions between CD4+ and CD8+ T cells, the functions of which are progressively impaired during the course of MAIDS.
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PMID:Opportunistic infections and retrovirus-induced immunodeficiency: studies of acute and chronic infections with Toxoplasma gondii in mice infected with LP-BM5 murine leukemia viruses. 132 58

We recently showed that hemopoietic stem cells expressing the v-abl oncogene can cause leukemia when injected into lethally irradiated recipient mice. Progenitor cells expressing v-abl did not significantly contribute to disease development, and the leukemia was monoclonal in origin. By serially transplanting v-abl-transduced hemopoietic stem cells into normal, nonirradiated syngeneic recipients, we showed that multiple stem-cell clones do exist in some recipients. These cells fluctuated as normal stem cells do and could home to normal bone marrow. Based on the time course of disease, the recipients developed either an acute or a chronic phase of disorder. All recipients with the acute disease had stem-cell clones with random Abelson murine leukemia virus integration sites. All recipients with the chronic disorder had a specific Abelson murine leukemia virus integration site. We believe this abl-specific integration site, termed ASI, is important in abl-mediated stem-cell leukemogenesis.
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PMID:Chronic myeloproliferative disease induced by site-specific integration of Abelson murine leukemia virus-infected hemopoietic stem cells. 168 23

We report the first complete nucleotide sequence (8,440 base pairs) of a biologically active feline leukemia virus (FeLV), designated FeLV-61E (or F6A), and the molecular cloning, biological activity, and env-long terminal repeat (LTR) sequence of another FeLV isolate, FeLV-3281 (or F3A). F6A corresponds to the non-disease-specific common-form component of the immunodeficiency disease-inducing strain of FeLV, FeLV-FAIDS, and was isolated from tissue DNA of a cat following experimental transmission of naturally occurring feline acquired immunodeficiency syndrome. F3A clones were derived from a subgroup-A-virus-producing feline tumor cell line. Both are unusual relative to other molecularly cloned FeLVs studied to date in their ability to induce viremia in weanling (8-week-old) cats and in their failure to induce acute disease. The F6A provirus is organized into 5'-LTR-gag-pol-env-LTR-3' regions; the gag and pol open reading frames are separated by an amber codon, and env is in a different reading frame. The deduced extracellular glycoproteins of F6A, F3A, and the Glasgow-1 subgroup A isolate of FeLV (M. Stewart, M. Warnock, A. Wheeler, N. Wilkie, J. Mullins, D. Onions, and J. Neil, J. Virol. 58:825-834, 1986) are 98% homologous, despite having been isolated from naturally infected cats 6 to 13 years apart and from widely different geographic locations. As a group, their envelope gene sequences differ markedly from those of the disease-associated subgroup B and acutely pathogenic subgroup C viruses. Thus, F6A and F3A correspond to members of a highly conserved family and represent prototypes of the horizontally transmitted, minimally pathogenic FeLV present in all naturally occurring infections.
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PMID:Strong sequence conservation among horizontally transmissible, minimally pathogenic feline leukemia viruses. 282 67

Rearrangement of the breakpoint cluster region (bcr) was demonstrated by Southern blot analysis in the DNA in each of 68 patients with Ph chromosome-positive CML and in 3 of 7 patients with apparent Ph chromosome-negative CML. In contrast, no bcr rearrangement could be found in DNA from 17 normal individuals and 28 patients with various hematologic disorders other than CML or ALL. An analysis of the location of the breakpoints within the bcr indicated that 3' breakpoints were significantly more common in patients in blast crisis or accelerated phase disease compared to those with chronic phase disease. Patients with chronic phase disease and 3' breakpoints had shorter average disease duration than that for chronic phase patients with 5' breakpoints, although the difference between these two groups of patients was not statistically significant. For patients who had progressed to accelerated disease or blast crisis, a statistically significant difference in chronic phase disease duration could be demonstrated between 11 patients with 3' breakpoints (average chronic phase 30.2 months) and 15 patients with 5' breakpoints (average chronic phase 50.6 months). For 8 patients studied in both chronic phase and accelerated or blast crisis, the location of the breakpoint did not change. We suggest that the bcr-abl fusion protein associated with a 3' breakpoint could result in more rapid progression to acute disease, and this may account for differences in the relative frequency of 3' and 5' breakpoints at different disease stages. Although more studies are required, identifying CML patients with a higher propensity for early blast transformation may eventually prove to be of some clinical value.
Leukemia 1988 Oct
PMID:The location of breakpoints within the breakpoint cluster region (bcr) of chromosome 22 in chronic myeloid leukemia. 317 41

Human tumour cell lines of various histological origin contain genes that can transform NIH 3T3 cells in culture. Most frequently the gene is an activated K-ras gene, more rarely an activated H-ras gene, and sometimes the recently discovered N-ras. Other transforming genes, distinct from ras, have been found in B- and T-cell leukaemias. Since most of the transforming genes have been identified in cell lines, it is still unclear at what stage the genes become activated. We have therefore initiated a study to determine if the presence of a transforming gene correlates with the clinical course of a malignant disease. Here we demonstrate the presence of a transforming N-ras gene in bone marrow cells from a patient with acute myeloblastic leukaemia at the outbreak of the acute disease phase. Fibroblast DNA from the same patient was not transforming. In contrast to HL-60 cells, no alteration of the myc gene was detected.
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PMID:Activation of N-ras gene in bone marrow cells from a patient with acute myeloblastic leukaemia. 658 53

There is evidence to suggest that infectious feline leukemia viruses (FeLVs) may be altered biologically because of homologous recombination with non-infectious endogenous FeLV (enFeLV) sequences in the infected cells. To evaluate the role of such recombination events in FeLV pathogenesis, a molecular clone of subgroup C FeLV, Sarma strain (FSC), was tested for induction of aplastic anemia in the absence or presence of mixtures of recombinants between FSC and an enFeLV element. In the recombinants, FSC sequences in the viral surface glycoprotein (SU) protein were variably replaced by the corresponding sequences of the enFeLV. The results showed that the virus mixtures varied in their infectivity to neonatal specific pathogen-free cats. One group of mixtures, although exhibiting relatively reduced infectivity, represented the most acute disease-inducing agents. The presence of recombinants in this mixture significantly accelerated the development of erythrocyte aplasia compared to cats infected with FSC alone. In addition, infected cells appeared to be distributed differently in various hematopoietic organs with respect to infection with FSC versus viral mixture. Viral recombinants which were present in this inoculum mixture, however, could not be detected in the plasma or infected tissues of the cats at the end stage of the disease, although their presence in the plasma at the early stages could be detected. Clearly, parental FSC outgrew the recombinants in the infected animals, since its detection was prominent at all stages of the progression of the disease. Therefore, we hypothesize that recombinants initially present in the infected animals, while only poorly replicated compared to FSC in the host, might have had the opportunity to infect certain target cells (potentially erythroid progenitor cells) and then disappeared with the associated cytopathic effect.
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PMID:Pathogenicity of a subgroup C feline leukemia virus (FeLV) is augmented when administered in association with certain FeLV recombinants. 825 54

Fever is an indication of acute disease, and needs special attention. To better understand the causes of fever in children, we analysed the records of 100 febrile children who were admitted to this Hospital from June 1987 to December, 1989. In these 100 cases, 7 days' fever prior to admission included 32 cases (32%); 7 to 14 days' fever prior to admission, 43 cases (43%); over 14 days' pre-admission, 25 cases (25%). The age distribution was younger than 1 month, 3 cases; 1 month to 1 year, 52 cases; 1 year to 2 1/2 years, 20 cases; 2 1/2 years to 5 years, 16 cases; 5 to 10 years 6 cases; older than 10 years included 3 cases. Post-admission diagnoses of these children showed most had an infectious disease: 86 cases; "summer fever": 5 cases; perineal abscess: 1 case; cellulitis: 1 case; leukemia, 2 cases; 5 were from other causes. Fevers were more prevalent in summer. In conclusion, the most common cause of prolonged fever in children is infectious disease 86%, with the highest incidence of age distribution under 2 1/2 years old, with 73%. The case distribution showed a prevalence in summer 43%. Almost all prognoses were good.
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PMID:[Clinical observation and analysis of febrile children]. 828 90


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