Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.11.1.7 (peroxidase)
 65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A myeloid leukemia cell line (TK-1) was established from the peripheral blood of a patient with lymphoblastic lymphoma whose leukemia cells were composed of T-lymphoblasts and immature myeloid cells. The established TK-1 cell line consisted of immature myeloid cells with heavy azurophilic granulation in the cytoplasm. The TK-1 cells were positive for peroxidase, and exhibited a strong positive reaction for alpha-naphthyl acetate esterase and naphthol AS-D chloroacetate esterase. The cells were weakly positive for Fc gamma-receptors, showed no phagocytosis and did not reduce NBT. With the treatment of 1 alpha, 25-dihydroxy-vitamin D3, they exhibited morphological and functional differentiation. The TK-1 cell line contained normal diploid cells and pseudodiploid cells, and the two populations were successfully cloned; the clone with a normal karyotype was designated the TK-1D cell line, and the clone with a pseudodiploid karyotype, which had a translocation involving chromosomes 14, 17 and one other chromosome, was designated the TK-1B cell line. These cloned cells lacked Epstein-Barr virus nuclear antigens and had almost the same myelomonocytic characteristics as the parent TK-1 cells. The breakpoint of chromosome 17 involved in the translocation of the pseudodiploid cells was identified to be a band 17q23.
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PMID:Establishment of a new myeloid leukemia cell line (TK-1), and isolation of cells having a translocation involving a band 17q23. 345 71

In some patients with genetic forms of extreme insulin resistance, there is a marked decrease in the number of insulin receptors on the cell surface. We studied an insulin-resistant patient (RM-1) with the Rabson-Mendenhall syndrome. As judged by insulin-binding studies, Epstein-Barr virus-transformed lymphocytes from patient RM-1 exhibit a 90% decrease in the number of insulin receptors. Similarly, with either lactoperoxidase-catalyzed radioiodination of cell surface receptors or biosynthetic labeling of receptors with [3H]glucosamine, we demonstrated an 80-90% decrease in the number of insulin receptors in cells from patient RM-1. Previous studies have shown that the marked decrease in insulin receptors of the Rabson-Mendenhall patient is not due to accelerated receptor degradation. Therefore, we investigated the possibility that a slow rate of receptor biosynthesis might account for the 90% reduction of insulin receptors in cells from this patient. Insulin-receptor biosynthesis proceeds through a glycoprotein precursor with an apparent Mr of 190,000. It undergoes endopeptidase cleavage and further posttranslational processing to yield the mature 135,000- and 95,000-Mr glycoprotein subunits. We studied the biosynthesis of the 190,000-Mr precursor and mature receptor subunits by a pulse-chase labeling technique with [2-3H]mannose. The time course of insulin-receptor biosynthesis appeared normal in cells from patient RM-1, despite a 10-fold reduction in the number of receptors on the cell surface. Parallel pulse-chase experiments with either [2-3H]mannose or [35S]methionine yielded the same results regardless of which label was employed. Thus, the receptor precursor in the Rabson-Mendenhall patient seems to be synthesized at a normal rat.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Insulin-receptor biosynthesis in cultured lymphocytes from an insulin-resistant patient (Rabson-Mendenhall syndrome). Evidence for defect before insertion of receptor into plasma membrane. 372 Oct 65

Experiments have been carried out to identify the polypeptide components of the Epstein-Barr (EB) virus-determined membrane antigen (MA) complex. Cells were radioiodinated using lactoperoxidase and the 125I-labelled surface antigens, released by Triton X100, were analysed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) after complexing either with human sera having anti-MA activity or with a rabbit antiserum to EB virus. Using cells carrying EB virus isolated from four different conditions, including for the first time nasopharyngeal carcinoma (NPC), we have demonstrated four major polypeptides. One, with a molecular weight of 85,000, was remarkedly constant irrespective of the cell line from which it came; two, with molecular weights varying from 240,000 to 270,000 and from 320,000 to 340,000, showed minor differences in mobility apparently depending on the species of origin of the cells (human or marmoset), rather than disparity between strains of virus. A fourth component, of 160,000 daltons, was found on only two of the cell lines studied. In addition, it has been shown for the first time that the same polypeptides composing the MA complex are present on the viral envelope itself. The fact that the rabbit antiserum to EV virus recognized only the two highest molecular weight MA components, yet showed virus-neutralizing activity, indicates the importance of these two polypeptides for use in a vaccine designed to induce virus-neutralizing antibodies.
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PMID:Observations on the EB virus envelope and virus-determined membrane antigen (MA) polypeptides. 616 6

Nine hybrid cell lines producing antibodies specific for cytomegalovirus (CMV) antigen were obtained after fusion of P3/X63-Ag8 myeloma cells with spleen cells from BALB/c mice immunized with CMV complement-fixing antigen. By the immunoblot technique, five of nine antibodies (4D11, 7B4, 7D2, 8E3, and 8E10) were identified as being reactive to a CMV glycosylated polypeptide with molecular weight of 66,000 (GP66). Four other antibodies (1B8, 8E9, 4D2, and 7E2) appeared to be reactive with CMV antigen(s) only if the antigen was not denatured by sodium dodecyl sulfate. These remain unassigned until further studies are done. With the enzyme-linked immunosorbent assay (ELISA), competitive bindings were performed with a constant amount of horseradish peroxidase-conjugated antibody and various concentrations of unconjugated homologous and heterologous antibodies on CMV antigen-coated ELISA wells, and the antigenic determinant specific for each antibody was determined. The nine antibodies could be classified into six different groups, each group reacting with a different epitope or a different region with two or more antigenic determinants which are so close to each other that they cause binding inhibition. They are groups A (4D11), B (7B4, 8E10), C (7D2), D (4D2, 7E2, 8E9), E (8E3), and F (1B8). The extent of competition among antibodies within each group was the same. By using the two antibodies that reacted with different epitopes on GP66, a double-antibody sandwich ELISA method was developed. The method was sensitive enough to detect as little as 50% of the antigen present in one infected cell or 0.000245 U of CMV complement-fixing antigen per test well. Other strains of CMV (David, Kerr, Espilat, C-87, and five clinical isolates) gave positive results, whereas herpes simplex virus types 1 and 2, varicella-zoster virus and Epstein-Barr virus nuclear antigen preparations did not. By the indirect immunofluorescence assay, antibodies 4D11 and 8E3 were able to detect GP66 in the nucleus of CMV-infected F-5000 human embryonic fibroblasts as early as 2 h postinfection and were superior in this respect to the remaining seven antibodies tested. By the double-antibody sandwich ELISA, the presence of GP66 in CMV-infected cells was detected as early as 2 h postinfection.
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PMID:Production and characterization of monoclonal antibodies specific for a glycosylated polypeptide of human cytomegalovirus. 619 74

A sensitive enzyme-linked immunosorbent assay (ELISA) is described for detection of varicella-zoster virus (VZV) IgM antibodies. The antigen consisted of a sonically disrupted extract of VZV-infected human embryo cells. The tested sera were absorbed with Staphylococcus aureus (strain Cowan I) before analysis. Rabbit anti-human IgM peroxidase conjugate was used to detect human IgM bound to viral antigen. The results were compared with those obtained by the indirect fluorescent antibody to membrane antigen (IFAMA) technique. Comparison of titers obtained by ELISA with those obtained by IFAMA for sera of chickenpox patients showed agreement between the results in 8 of 9 patients. In 1 chickenpox patient, no VZV IgM antibodies could be detected by IFAMA, while a titer of 3,200 was obtained by ELISA. The ELISA technique described gave titers more than 100 times higher than those obtained by IFAMA. VZV IgM antibody was detected by ELISA and IFAMA in only 1 of 5 zoster patients. No VZV IgM antibodies were found by ELISA in 45 control sera (healthy adults and hospitalized patients with various other diseases). Neither were they found in paired sera of 6 patients with acute herpes simplex infections, 2 patients with Epstein-Barr virus infections, and 3 patients with human cytomegalovirus infections.
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PMID:Enzyme-linked immunosorbent assay for detection of virus-specific IgM antibodies to varicella-zoster virus. 624 82

A sensitive enzyme-linked immunosorbent assay (ELISA) is described for detection of IgA antibodies cytomegalovirus (CMV). The antigen consisted of a sonicated extract of CMV infected human embryo cells. The tested sera were absorbed with staphylococcus aureus (strain Cowan 1) before analysis. Rabbit antihuman IgA peroxidase conjugate was used to detect human IgA bound to viral antigen. In parallel, Igm and IgG antibodies to CMV were studied by ELISA and by the immunoperoxidase antibody to membrane antigen (IPAMA) technique, respectively. CMV IgA was detected in high titers by ELISA in eight of nine CMV patients. The maximal IgA titers were generally lower than the IgM titers detected by ELISA. No CMV IgA antibodies (titer less than 20) were detected by ELISA in 57 control sera (healthy adults, hospitalized patients with various other diseases), paired sera of five patients with acute herpes simplex, infection, two patients with Epstein-Barr infections, one patients with varicella, and one with zoster infections. The potential application of the ELISA CMV IgA technique in serodiagnosis of CMV infections is discussed.
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PMID:Determination of IgA antibodies to human cytomegalovirus by enzyme-linked immunosorbent assay (ELISA). 626 58

A micro-ELISA technique was developed for the detection of Epstein-Barr virus (EBV)-determined antigens. The enzyme-linked immunosorbent assay (ELISA) was applied with peroxidase-protein A to detect the antigens adsorbed to micro-ELISA plates. Human and rabbit antisera containing antibodies to known EBV components were used as reagents. The early antigen (EA) complex, associated with the viral cycle, was readily detected in extracts of n-butyrate- or n-butyrate + TPA-induced cells. The nuclear antigen, EBNA, could be unequivocally detected only after the partial purification of the antigen by DNA cellulose chromatography. EA (and VCA) could be separated by chromatofocusing of induced cell extracts into several fractions detected by the micro-ELISA technique. This indicates that the purification of individual antigens of the EA complex can be monitored by ELISA.
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PMID:Detection and characterization of EBV antigens by micro-ELISA and chromatofocusing. 628 3

A myeloid cell line, designated PL-21, was established from the peripheral blood of a patient with acute promyelocytic leukemia. The PL-21 cell line grew in single-cell suspension, with a doubling time of 48-64 hr, and consisted of promyelocytes with fine immature nuclei and prominent azurophilic granules in the cytoplasm. PL-21 cells were positive for peroxidase, naphthol AS-D chloroacetate esterase, and Sudan Black B staining. Under the usual culture conditions, a small proportion of these cells differentiated into mature granulocytes, and this differentiation was enhanced by the addition of dimethyl sulfoxide in the culture medium. PL-21 cells had receptors for the Fc portion of IgG and complement, intracytoplasmic lysozyme and phagocytic activity, but lacked Epstein-Barr virus-associated nuclear antigen. Chromosome analysis of this cell line revealed a human male polyploid karyotype with 13q+ and double minute chromosomes. This new myeloid cell line may provide useful material for the study of proliferation and differentiation of human leukemia cells.
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PMID:Establishment of a new peroxidase-positive human myeloid cell line, PL-21. 636 49

Previous studies of the insulin receptor in disease states have utilized primarily techniques of equilibrium binding and, to a limited extent structural, analysis. Though techniques have been developed to study receptor degradation in normal cells, they have not been applied to disease states. In the present study we have examined insulin receptor degradation rate in B lymphocytes that were obtained from peripheral blood of normal subjects and patients with several syndromes of extreme insulin resistance. B lymphocytes were established in culture from each patient's peripheral cells by transformation with Epstein-Barr virus. The insulin receptors were surface labeled using Na125I/lactoperoxidase and the cells were returned to incubate in growth media. After varying periods of incubation, aliquots of cells were solubilized and the cell content of labeled receptor subunits were measured by immunoprecipitation with anti-receptor antibodies and NaDodSO4/polyacrylamide gel electrophoresis. The fall in 125I-insulin receptor content approximated a single exponential and was quantitated as receptor subunit half-life (t1/2). In cell lines from four patients in whom the number of insulin receptors was reduced by greater than 90%, the rate of receptor loss was greater than normal (t1/2 equals 3.8 +/- 0.9 h vs. 6.5 +/- 1.2 h; mean +/- SD, P less than 0.01). However, a similar acceleration in receptor degradation was seen in cells from five patients with extreme insulin resistance but low-normal insulin receptor concentration (t1/2 equals 4.4 +/- 0.9 h). This group included cells from one patient with a qualitatively abnormal receptor. Thus, all the patients with genetic syndromes of insulin resistance had accelerated receptor degradation, regardless of their receptor concentration. By contrast, insulin receptors on cultured lymphocytes that were obtained from patients with extreme insulin resistance secondary to autoantibodies to the insulin receptor had normal receptor degradation (t1/2 equals 6.1 +/- 1.9 h). We conclude that (a) accelerated insulin receptor degradation is an additional feature of cells from patients with genetic forms of insulin resistance; (b) that accelerated insulin receptor degradation may explain the low-normal receptor concentrations that were seen in some patients with extreme insulin resistance; and (c) that accelerated degradation does not explain the decreased receptor concentration in patients with very low insulin receptor binding and, therefore, by inference, a defect in receptor synthesis must be present in this subgroup.
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PMID:Insulin receptor degradation is accelerated in cultured lymphocytes from patients with genetic syndromes of extreme insulin resistance. 648 Aug 29

A patient with Philadelphia chromosome (Ph1) positive chronic myelogenous leukemia (CML) entered a blast crisis localized to lymph nodes. On light microscopy, by morphology and histochemical staining, the blasts were undifferentiated. In spite of terminal deoxynucleotidyl transferase positivity, some of the lymph node cells expressed a myeloid differentiation antigen, OKM1, and were peroxidase positive by transmission electron microscopy (TEM). However, the majority of cells were peroxidase negative on TEM and expressed OKT-10, a marker found on both primitive myeloid and lymphoid cells. Cultures of lymph node cells stimulated with Epstein-Barr virus or lipopolysaccharide (LPS) revealed the Ph1, indicating B cell involvement in the CML. T cells from cultures stimulated with L4-phytohemagglutinin and T cell growth factor were negative for the Ph1. In unstimulated lymph node cells, the uncomplicated Ph1 could not be demonstrated; instead, a unique complex karyotype involving a masked Ph1 was identified in these and the LPS cultures. This karyotype was not found in bone marrow (BM) metaphase cells. Instead, BM cells showed either the simple Ph1 or the Ph1 with a rearrangement involving chromosomes 13 and 20. The patient had transient responses to three chemotherapy regimens, two of which were designed to treat acute lymphocytic leukemia, but he died 8 months after disease acceleration without BM blast crisis. These findings are compatible with an extramedullary blast crisis originating in a primitive cell with both myeloid and lymphoid characteristics.
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PMID:Unusual karyotypic changes and B cell involvement in a case of lymph node blast crisis of chronic myelogenous leukemia. 661 Apr 45


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