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Lymphoblasts from 93 children with acute lymphoblastic leukemia (ALL) were characterized by immunologic cell surface markers. These patients were treated on a single protocol,featuring adriamycin therapy during remission,and have been followed from 2 to 6.5 yr (median 4 yr). Three classes of patients were defined serologically: HTA+ Ia- CALLA-,Ia+ CALLA+ HTA-,and Ia+ CALLA- HTA-. Disease-free survival and sites of relapse were assessed within immunologic subsets. Similar to the findings of others,T-cell (HTA+ Ia-) patients fared poorly as compared to non-T-cell (Ia+ HTA-) patients (median disease-free survival was 12 and 47 mo. respectively; p = 0.0004). The majority of relapses in the HTA+ patients occurred at extramedullary sites. Late testicular relapse was rare among Ia+ patients. In addition,the common ALL antigen" (CALLA) may identify a relatively favorable subset within the Ia+ population. The prognostic value of the immunologic markers was compared with traditional clinical factors. There was much overlap between HTA+� View Publication

This report describes the establishment directly from normal preimplantation mouse embryos of a cell line that forms teratocarcinomas when injected into mice. The pluripotency of these embryonic stem cells was demonstrated conclusively by the observation that subclonal cultures,derived from isolated single cells,can differentiate into a wide variety of cell types. Such embryonic stem cells were isolated from inner cell masses of late blastocysts cultured in medium conditioned by an established teratocarcinoma stem cell line. This suggests that such conditioned medium might contain a growth factor that stimulates the proliferation or inhibits the differentiation of normal pluripotent embryonic cells,or both. This method of obtaining embryonic stem cells makes feasible the isolation of pluripotent cells lines from various types of noninbred embryo,including those carrying mutant genes. The availability of such cell lines should made possible new approaches to the study of early mammalian development. View Publication

Sinefungin (A9145) and a related metabolite,A9145C,were found to be potent inhibitors of Newcastle disease virion and vaccinia virion mRNA(guanine-7-)-methyltransferase and vaccinia virion mRNA(nucleoside-2'-)-methyltransferase. Both Sinefungin and A9145C were competitive inhibitors of these S-adenosyl-L-methionine-dependent enzymes having inhibition constants substantially less than S-adenosyl-L-homocysteine. These compounds also inhibited plaque formation by vaccinia virus in mouse L-cells. View Publication

The electrophoretic pattern of the large microtubule-associated protein,MAP2,changes during rat brain development. Immunoblots of NaDodSO4 extracts obtained from the cerebral cortex,cerebellum,and thalamus at 10-15 days after birth reveal only a single electrophoretic species when probed with any of three MAP2 monoclonal antibodies. By contrast,adult MAP2 contains two immunoreactive species,MAP2a and MAP2b. The single band of MAP2 from immature brain electrophoretically comigrates with adult MAP2b. Between postnatal days 17 and 18,immature MAP2 simultaneously resolves into two species in both the cerebellum and cerebral cortex. Immunoblots of NaDodSO4 extracts from spinal cord demonstrate the adult complement of MAP2 by day 10,indicating that MAP2 does not change coordinately throughout the entire central nervous system. In vitro cAMP-dependent phosphorylation of immature MAP2 causes a band split reminiscent of that seen during brain development in vivo. The possibility that the developmentally regulated changes observed in MAP2 during brain maturation are due to timed phosphorylation events is discussed. View Publication

The anti-My-10 mouse monoclonal antibody was raised against the immature human myeloid cell line KG-1a and was selected for nonreactivity with mature human granulocytes. Anti-My-10 immunoprecipitated a KG-1a cell surface protein with an apparent Mr of approximately 115 kD. We describe the binding of this antibody to human hematopoietic cell types and show that My-10 is expressed specifically on immature normal human marrow cells,including hematopoietic progenitor cells. My-10 is also expressed by leukemic marrow cells from a subpopulation of patients. Thus,this antibody allows the identification and purification of hematopoietic progenitor cells from normal human marrow and the subclassification of leukemia. View Publication

Four monoclonal antibodies against antigens of human myeloid cells have been produced and thoroughly characterized in terms of their reactions with peripheral blood cells,cell lines,nine lymphoid and non-lymphoid tissues and the polypeptides with which they react. UCHM1 and SmO identify antigens present on the majority of blood monocytes and a variable,but lower,proportion of tissue macrophages. From their morphology and location in tissues,these cells appear to be recirculating monocytes. SMO antigen is also present on platelets. In addition,both antibodies stained endothelial cells,SMO in all tissues examined and UCHM1 variably. Biochemical investigation indicated that the UCHM1 antigen is a protein of 52,000 MW while the SMO antigen could not be indentified. The antibodies TG1 and 28 identify antigens mainly present on granulocytes. While mAb 28 reacted with neutrophils,TG1 also stained eosinophils and stained strongly a proportion of monocytes. TG1 also reacted variably with some non-haemopoietic cell lines. Both antibodies reacted predominantly with granulocytes in tissue sections. MAb TG1 precipitated a single polypeptide of 156,000 MW from monocytes and granulocytes,while mAb 28 precipitated non-convalently associated polypeptides of 83,000 and 155,000 MW from granulocytes but only a single molecule from monocytes,corresponding to the lower MW chain of 83,000. The epitope with which mAb 28 reacts appears not to be exposed on the surface of intact monocytes. This suggests that a similar or identical 83,000 MW molecule is made by both neutrophils and monocytes,but that its expression differs according to cell type. View Publication

A hybrid cell line resulting from the fusion of a Con A-activated normal mouse spleen cell and a transformed mouse T cell (EL-4BU) has been used to prepare and select rat monoclonal antibodies reactive with molecules expressed on the surface of proliferating,as opposed to resting,mouse T cells. In this report,the characterization of two such antigens identified in this way is described. One antigen is a membrane component common to mitogen-activated T and B cells,some bone marrow cells,and various transformed cell lines but is not detectable on either normal thymocytes or the majority of spleen cells by radioimmunoassay or FACS analysis. It has a m.w. of approximately 200,000 daltons under nonreducing conditions and 100,000 daltons under reducing conditions. Antibodies to this antigen precipitate cell-bound transferrin but do not react directly with transferrin itself. It would thus appear that the antigen is the transferrin receptor molecule. The second antigen is not detectable on normal thymocytes,spleen cells,bone marrow cells,or mitogen-stimulated spleen cells but is expressed at high levels on some transformed T cell lines. It,too,appears to be a dimer,with a m.w. of 95,000 daltons under nonreducing conditions,decreasing to 50,000 daltons under reducing conditions. Although the function of the 95,000-dalton antigen is not yet known,its lack of expression on adult T cell populations both before and after activation suggests either a short-lived role at a very early stage of T cell development and/or an association with T cell transformation. View Publication

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The acute lymphoblastic leukemia- (ALL) associated membrane antigen is a single glycosylated polypeptide of approximate m.w. of 100,000 (gp100),containing no intrachain disulfide linkages. Approximately 50% of gp100 will bind to lentil lectin,whereas 100% will bind to the lectin from Ricinus communis. Both lentil-binding and lentil nonbinding forms of the antigen appear to be identical by 2-dimensional isoelectric focusing/SDS polyacrylamide gel electrophoresis and peptide mapping. Carbohydrate,although contributing approximately 20 to 25% of the m.w.,appears not to be involved in the antigenic site of the ALL antigen as judged by precipitation of a molecule after tunicamycin treatment of cells or glycosidase digestion. Charge shift electrophoresis and labeling with the lipophilic nitrene reagent hexanoyl diiodo-N-(4-azido-2-nitrophenyl)-tyramine suggests that the cALL antigen is probably not an integral membrane protein; however,it remains tightly bound to the plasma membrane after subcellular fractionation. A glycoprotein of the same m.w. has been detected by immunoprecipitation on bone marrow cells of nonleukemic patients. serologic studies indicate that the cALL-associated antigen is found on the terminal transferase-positive lymphoid cells,and it therefore seems likely that the gp100 molecule is a normal gene products of lymphocyte precursors. View Publication

Sinefungin,a naturally occurring antifungal antibiotic nucleoside containing an ornithine residue,linked by a C-C bond to C-5' of adenosine,cures mice infected with Trypanosoma brucei brucei,T. congolense,or T. vivax; the effect of the drug is more pronounced towards T. congolense. Anti-trypanosomal activity of sinefungin could be the result of the inhibition of transmethylation reactions or of polyamine biosynthesis--or both--in parasites. View Publication

After a single intravenous injection of suramin the rate of removal of the drug from the plasma into other tissue compartments of the rat is independent of initial concentration. The data can be fitted to the sum of two exponential functions,consistent with a two-compartment,open model system. Trypanosomes take up only small amounts of suramin in vivo and do not actively concentrate the drug within the cell. Uptake is apparently by a non-saturable process that decreases with time and is dependent on the amount of suramin already taken up. Once within the cell,suramin progressively inhibits respiration and glycolysis,such that,for a given exposure in vivo,inhibition of oxygen consumption is proportional to the total amount of suramin absorbed. It can be calculated that only a fraction (4--9%) of this total is required to inhibit respiration to the extent found in broken cell preparations. The combined inhibition of two key enzymes in glycolysis--the sn-glycerol-3-phosphate oxidase (EC unassigned) and the glycerol-3-phosphate dehydrogenase (NAD+) (sn-glycerol-3-phosphate: NAD+ 2-oxidoreductase,EC 1.1.1.8)--are sufficient to account for the differential inhibition of glucose and oxygen consumption and of pyruvate production,together with the small,but significant,production of glycerol. Even at the highest dose of suramin tolerated by the rat,trypanosomes continue to increase exponentially in the bloodstream for at least 6 h. The mean doubling time is increased from 4.6 h to a maximum of about 12.5 h in rats treated with doses of suramin in the range 25--150 mg/kg. In the light of these and other findings,it is concluded that part of the trypanocidal action of suramin results from the inhibition of ATP production by glycolysis. View Publication

Mononuclear cells separated from the blood in fourteen cases of infectious mononucleosis at various intervals from the onset were tested for the presence of surface immunoglobulin and for ability to form spontaneous rosettes with washed sheep red blood cells. The mononucleosis during the acute phase of the illness consisted largely of a T lymphocytosis. The absolute count of T lymphocytes returned to the normal range approximately 2 months after the onset of the illness. B cells (bearing surface immunoglobulin) were only slightly increased in the acute phase. In four cases appreciable numbers of fluorescent rosetting cells were also present,and investigation suggested that these were T cells coated with anti-T-cell autoantibody. During the first 2 weeks of the illness responsiveness to phytohaemagglutinin was severely depressed,but thereafter returned towards normal. It is thought likely that in infectious mononucleosis the vast majority of atypical mononuclear cells are T cells proliferating in response to E-B virus-infected B cells,and cytotoxic towards them. View Publication