Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The number and distribution patterns of lymphocytes in the spleens and lymph nodes of Balb/c mice which express immunoglobulin surface receptors were studied in terms of the effects of a murine leukemia virus on the immune-response mechanism. Friend leukemia virus induces a prompt, marked depression of the immune response of mice to antigens such as sheep erythrocytes and E. coli LPS. A functioning T- and B-lymphocyte system is necessary for the response to the SRBC's whereas E. coli LPS, a T cell-independent antigen, stimulates B cells alone. Although the responses to both classes of antigen were markedly depressed in FLV-infected mice, the major defect appeared to be impairment of B-cell function, at least early in the course of infection. In order to examine in more detail the mechanism of interaction between FLV and lymphoid cells with Ig surface receptors, presumably B cells, immmunofluorescent analyses were performed with spleen, and lymph node cells from FLV-infected mice. Within a few days after infection there was a marked decrease in the percentage of spleen cells with Ig surface molecules, although the absolute number of these cells was either unchanged or increased due to marked splenomegaly caused by the virus. A marked decrease in the percentage of splenocytes with theta antigen, considered a marker for mature T cells, also was evident in infected mice. The number of spleen cells showing evidence of FLV infection (i.e., positive for FLV-associated antigens) increased rapidly during the first few days after infection, and within 2 to 2 1/2 weeks nearly all of the nucleated splenocytes were positive for the tumor antigen. In contrast to the results for spleen cells, there were increases rather than decreases in the percentages of Ig-positive and theta-positive cells in the lymph nodes after infection. The number of lymph-node cells that showed the presence of FLV antigen was much lower than in the spleen, and their appearance was also much slower as the leukemic process progressed. Despite these differences between spleen and lymph-node cells in terms of relative percentages of Ig- and theta-positive lymphocytes, relatively similar depressions were evident for the percentages of lymphoid cells that could redistribute their surface Ig receptors into polar caps when incubated with anti-Ig serum at 37 C. Marked impairment of the Ig-capping responses for both spleen and lymph-node cells paralleled the course of infection and development of immunosuppression. These observations indicate that murine leukemia virus infection can both alter the responsiveness of immunocompetent cells to T-dependent and independent antigens and depress the number and normal functional activity of these cells, as reflected by altered surface Ig receptors and antigens.
 ...
PMID:Lymphocyte surface receptors and leukemia virus-induced immunosuppression. 109 86

To understand further the hematopoietic dyscrasias induced by a variant (a) of Rauscher leukemia virus (RLV), we used Escherichia coli endotoxin to stress the hematopoietic system of control and RLV/a-infected BALB/c mice. During the preleukemic stages of virus infection, there was slight splenomegaly without peripheral blood erythroblastosis. Granulocyte release and tissue mobilization mechanisms appeared unaffected by the RLV/a infection. Both RLV/a-infected and control mice reacted to endotoxin with peripheral granulocytosis and peritoneal granulocyte mobilization, though the circulating granulocyte levels in RLV/a-treated mice initially were lower than those in controls. Spleen of RLV/a-infected animals were larger than those of controls, but both responded to endotoxin with elevated numbers of granulocytes and erythroblasts. Since numbers of bone marrow erythroblasts in both groups of mice were decreased after endotoxin, stem cell competition and/or shunting of stem cells from marrow to spleen may have been involved. Endotoxin also induced rapid falls in hematocrit levels in both groups. These studies suggested that RLV/a-infected mice can be a model to study 1) erythropoietic dysfunction uncomplicated by defective granulopoietic release and tissue mobilization control mechanisms, and 2) progression of evolving granulocytic leukemia.
 ...
PMID:Granulopoiesis in "preleukemic" mice with anemia induced by Rauscher leukemia virus, variant a. 110 69

Friend murine leukemia virus induces splenic enlargement and an increase in RNA polymerase activity of spleen nuclei. Actinomycin D, administered at 60 mug/kg body weight/day prevents the development os splenomegaly and the elevation of polymerase activity following infection, but it has only a slight effect on the production of virus in spleen tissue. Thus, the alteration of RNA synthesis is not a result of virus proliferation, but instead may be a manifestation of leukemic erythropoiesis. Normal erythropoiesis, stimulated by erythropoietin administration, produces a similar but transient increase in RNA polymerase activity in spleen nuclei. Erythropoietin administered before, but not after, Friend virus infection results in an enhancement of RNA polymerase activity, as measured 9 days after inoculation. This effect is most simply explained by assuming that there is a common target cell pool for both erythropoietin and Friend virus, and that this pool becomes refractory to the influence of the hormone as a result of the leukemic process.
 ...
PMID:Role of cellular RNA polymerases in virus-induced leukemogenesis. 114 21

Lewis lung adenocarcinoma growth was retarded by the oral administration of delta9-tetrahydrocannabinol (delta9-THC), delta8-tetrahydrocannabinol (delta8-THC), and cannabinol (CBN), but not cannabidiol (CBD). Animals treated for 10 consecutive days with delta9-THC, beginning the day after tumor implantation, demonstrated a dose-dependent action of retarded tumor growth. Mice treated for 20 consecutive days with delta8-THC and CBN had reduced primary tumor size. CBD showed no inhibitory effect on tumor growth at 14, 21, or 28 days. Delta9-THC, delta8-THC, and CBN increased the mean survival time (36% at 100 mg/kg, 25% at 200 mg/kg, and 27% at 50 mg/kg, respectively), whereas CBD did not. Delta9-THC administered orally daily until death in doses of 50, 100, or 200 mg/kg did not increase the life-spans of (C57BL/6 times DBA/2)F1 (BDF1) mice hosting the L1210 murine leukemia. However, delta9-THC administered daily for 10 days significantly inhibited Friend leukemia virus-induced splenomegaly by 71% at 200 mg/kg as compared to 90.2% for actinomycin D. Experiments with bone marrow and isolated Lewis lung cells incubated in vitro with delta9-THC and delta8-THC showed a dose-dependent (10(-4)-10(-7)) inhibition (80-20%, respectively) of tritiated thymidine and 14C-uridine uptake into these cells. CBD was active only in high concentrations (10(-4)).
 ...
PMID:Antineoplastic activity of cannabinoids. 115 36

Three hundred and three cases of polycythaemia vera were treated between 1949 and 1961 using radioactive phosphorus, the minimum follow-up for the patients in the group being 12 years and the maximum 24 years. Two hundred and thirty three patients died, the median duration of survival after the first treatment with phosphorus being 10 years (i.e. 12 years after the diagnosis was made). 59 patients died of the vascular complications of polycythaemia, 76 of leukaemia or myelofibrosis. The total number of deaths due to vascular complications up to the tenth year exceeded the total number of deaths due to haematological complications (leukaemia or myeloid metaplasia). At the end of the 11th year the opposite was true. From the ninth year onwards, acute leukaemia and myelofibrosis represent more than 40 p.cent of deaths of known cause and the annual probability of death from a haematological cause for the surviving patients increases regularly until the fifteenth year when it reaches approximately 5 p.cent of the patients at risk. However the median survival of patients dying from acute leukaemia or myeloid splenomegaly is slightly longer than that of patients dying from other causes, this confirming that these disorders would appear to represent the terminal phase in the course of polycythaemia vera.
 ...
PMID:[Fate of polycythemia vera treated by radioactive phosphorus. Apropos of a series of 303 patients followed for 12 to 24 years]. 116 78

The influence of Trichinella spiralis on the course of Rausher leukemia in mice was studied. Inoculation of mice with Trichinella spiralis larvae 15, 16 and 30 days before infection with Rausher leukemia virus was shown to stimulate splenomegaly, whereas preinoculation of Rausher leukemia virus at 6, 12 and 18 days before infection with Trichinella spiralis resulted in inhibition of splenomegaly. Under the experimental conditions used, no effect of T. spiralis on reproduction of Rausher leukemia virus was observed, as virus titers in the plasm of mice with marked stimulation or inhibition of splenomegaly were identical and did not differ from those in mice without Trichinella spiralis invasion.
 ...
PMID:[Effect of Trichinella spiralis infection on the development of Rauscher leukemia]. 116 55

A 76-year-old man with spontaneous rupture of a hemangiosarcoma of the spleen, together with a review of 49 previously reported patients with splenic hemangiosarcoma are presented. Twenty-three were women and 27 were men. All but 3 were adults. Fiften were 50-59 years of age. The symptomatology was nonspecific. Three patients developed microangiopathic hemolytic anemia. Spontaneous rupture occurred in 17 cases (34%). Metastases occurred in 42 cases; they were primarily hematogenous and most often in the liver. Lymph node involvement, however, was present in 13 cases. The prognosis of untreated splenic hemangiosarcoma is poor. Three of 25 patients survived a year or more after the initial onset of symptoms. Splenectomy before rupture is advisable, since 5 of 19 patients survived at least 1-5 years. It is suggested that hemangiosarcoma be considered in patients with: 1) splenomegaly without evidence of malignant lymphoma or leukemia, 2) splenomegaly with microangiopathic hemolytic anemia, and 3) unexplained intraperitoneal hemorrhage.
 ...
PMID:Hemangiosarcoma of spleen with spontaneous rupture. 116 82

Several derivatives of rifamycin, and analogs of the tilorone-fluoranthene group were tested for inhibition of splenic enlargement in Friend virus leukemia. At least three members of the rifamycin group caused significant inhibition (31-49%) as did at least three members of the tilorone group (32-48%). These six compounds are among those found by others (6, 7) to be most inhibitory in vitro to the RNA-directed DNA polymerase of oncornaviruses. However our studies do not furnish direct evidence for or against a role of inhibition of the viral enzyme in the suppression of splenomegaly. None of the agents was as effective as methotrexate, which caused 90-92% inhibition. The activity of five of the agents was reduced, rather than enhanced by the injection of adjuvants (M. butyricum and pertussis vaccine). Three of the agents had a subtractive, rather than an additive effect on the inhibition caused by methotrexate alone.
 ...
PMID:Effect of rifamycin and tilorone derivatives on Friend virus leukemia in mice. 118 8

The humoral immune response to Friend virus leukemia was studied in congenic F1 mice differing in their incidence of recovery from leukemia. Antiviral neutralizing antibodies rose in titer in vivo concurrently with disappearance of viremia and fall in spleen virus levels. Cytotoxic antileukemia cell antibodies also appeared at this time. Passive transfer of these antibodies could inactivate low numbers of leukemia cells in vivo; however, mice of both high and low recovery genotypes produced antibodies in equal titer and recovered from viral infection in spite of striking differences in recovery from leukemic splenomegaly. Mice lacking C57BL genes did not produce antibodies or recover from viremia except in rare instances. Recovery from splenomegaly was found to be influenced by three or more C57BL genes independent of the H-2 complex.
 ...
PMID:Studies on the role of the host immune response in recovery from Friend virus leukemia. I. Antiviral and antileukemia cell antibodies. 124 22

A human Philadelphia-chromosome positive chronic myeloid leukemia-blast crisis (CML-BC) cell line BV173 proliferated in the hematopoietic tissues, infiltrated various organs and caused the death of immunodeficient SCID mice. Leukemia spreading was assessed with diminished number of bone marrow cells and caused splenomegaly. The leukemic colonies grew from single cell suspension of bone marrow, spleen and peripheral blood. Bcr-abl m-RNA was detectable in bone marrow, spleen, peripheral blood, liver, lungs and brain. Dying mice demonstrated severely hypoplastic bone marrow, splenomegaly and massive metastases in the liver and kidneys. The survival time of animals was dependent on the number of inoculated leukemia cells.
 ...
PMID:A model of Ph' positive chronic myeloid leukemia-blast crisis cell line growth in immunodeficient SCID mice. 128 28


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