Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

ABL-MYC, a recombinant murine retrovirus that expresses v-abl and c-myc, rapidly induces transplantable mono- or oligoclonal plasmacytomas in BALB/c mice. To determine if the targets for transformation of this retrovirus are antigen-committed B lymphocytes and to explore this system as an alternative technique for producing antigen-specific monoclonal antibodies, plasmacytomas were induced in mice that had been immunized with two different types of immunogens, hen egg white lysozyme and sheep red blood cells. The majority of these plasmacytomas secreted immunogen-specific antibodies. Plasmacytomas induced in unimmunized mice did not react with hen egg white lysozyme or sheep red blood cells. The specific antibodies were comparable in concentration, specificity, and affinity to monoclonal antibodies obtained with conventional hybridoma technology, but, in addition to IgGs and IgMs, they included specific IgA antibodies, which are rare among splenic-derived hybridomas. Our results demonstrate that a principal target for ABL-MYC is an antigen-committed B lymphocyte. In addition this procedure provides an alternative method for the production of monoclonal antibodies, without a requirement for hetero-caryon formation by cell fusion techniques.
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PMID:Induction of plasmacytomas secreting antigen-specific monoclonal antibodies with a retrovirus expressing v-abl and c-myc. 192 33

Lysozyme, a hitherto myelomonocytic marker, has been previously reported as being raised in the sera of some myeloma patients. This fact, and the sporadical observation of a positive immunohistochemical lysozyme staining seen in some myelomas, prompted us to systematically search for an expression of lysozyme in both neoplastic and reactive plasma cells. A total of 74 paraffin-embedded, formalin-fixed, EDTA-decalcified core biopsies of newly diagnosed cases of plasmacytoma were immunohistochemically investigated for lysozyme expression by a modified avidin-biotin immunoperoxidase technique. The myelomas were subclassified according to their nuclear maturity into poorly differentiated plasmacytoma (PDP) (30 cases), moderately differentiated plasmacytoma (MDP) (24 cases), and well differentiated plasmacytoma (WDP) (20 cases). An unexpected lysozyme positivity was seen in 16/74 cases, and was most prevalent in 10/30 cases of PDP. No correlation has been detected between either lysozyme and kappa or lambda light chain expression, or an abnormal activity of chloroacetate esterase sometimes seen in myeloma. Since lysozyme has not been found in normal plasma cells or reactive plasmacytosis, the expression of this antigen in myeloma represents another example of so-called lineage infidelity, and parallels the previously reported abnormal expression of other myelomonocytic markers in some myelomas and a myeloma cell line. Apart from the unsettled prognostic impact, a facultative lysozyme expression in myeloma must be always considered when applying algorhythmic immunohistological strategies in delineating the histogenesis of haematopoietic or lymphatic malignancies.
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PMID:The expression of lysozyme in multiple myeloma. 752 45

We report the cases of two men, aged 48 and 71 years, with granulocytic sarcoma of the testis. Both presented with left testicular swelling and underwent orchiectomy, which revealed cream-colored to yellow-tan, rubbery-to-firm, testicular tumors with extensive paratesticular spread. The tumor in the younger patient was composed of a uniform population of primitive cells with scant cytoplasm and was initially misinterpreted as malignant lymphoma. Staging revealed no extrascrotal spread. The patient was treated with radiation and chemotherapy and remained free of disease for 12 years, at which time he died of unrelated causes. The older patient had a history of a myelodysplastic syndrome. His tumor contained cells with bright eosinophilic, occasionally granular cytoplasm, consistent with myeloid lineage. Because of a prominent component of myelocytes, with round, eccentric nuclei and moderately abundant cytoplasm, and because of an associated chronic inflammatory cell infiltrate that contained mature plasma cells, the tumor was initially misinterpreted as a plasmacytoma, although it was reinterpreted as a granulocytic sarcoma before initiation of therapy. Tumor cells in both cases were positive with a chloroacetate esterase stain. Immunohistochemical staining revealed expression of myeloperoxidase, lysozyme, leukocyte common antigen, and CD43, but not of B-cell-specific or T-cell-specific antigens in both cases. Granulocytic sarcomas are apt to be misinterpreted as other hematolymphoid tumors, which may result in a significant error in management. The diagnosis should at least be thought of any time the diagnosis of malignant lymphoma or plasmacytoma of the testis is being considered.
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PMID:Granulocytic sarcoma of the testis: a report of two cases of a neoplasm prone to misinterpretation. 911 Feb 93

Although plasma cells are terminally differentiated B cells, neoplastic plasma cells frequently express not only pre-B cell antigen, but also megakaryocytic, myelomonocytic, or erythroid markers. Since morphologic diagnosis of plasmacytoma is based on the recognition of neoplastic cells closely resembling normal plasma cells, unusual morphologic variants of neoplastic cells associated with these aberrant immunohistochemical features frequently cause diagnostic difficulty. The authors report a case of plasmacytoma with cleaved nuclei and myelomonocytic features occurring in the clavicle. The tumor was composed of immature plasma cells showing irregular, cleaved, and multilobated nuclei and abundant cytoplasm with prominent eosinophilic granules. A few tumor cells showing recognizable plasmacytic differentiation were admixed within the tumor. Immunohistochemically, the tumor cells expressed CD45RB, CD68, lysozyme, myeloperoxidase and kappa light chain with focal positivity for lambda chain. Ultrastructurally, the tumor cells contained numerous membrane bound electron dense lysosomal granules, some of them resembling Auer rods, as well as rough endoplasmic reticula arranged in lamellated stacks. Small biopsied nasal mucosal tissue in same patient revealed well differentiated plasmacytoma composed of tumor cells showing round, eccentric nuclei devoid of marked nuclear cleavage and cytoplasmic granularity. Immunohistochemically, these cells were kappa(+), lambda(-), myeloperoxidase(-), lysozyme(-) and CD68(-).
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PMID:Cleaved variant of plasmacytoma with myelomonocytic differentiation--immunohistochemical and ultrastructural studies. 936 3

We have previously identified and cloned an alternatively spliced form of human interleukin-6 mRNA lacking exon II, which encodes amino acid residues known to be important in gp130-mediated signal transduction pathways. We expressed and purified the recombinant protein (rIL6-alt) resulting from this alternatively spliced mRNA and now report the initial characterization of its biologic activities with comparison to full length IL6 (rIL6-full). rIL6-alt was found to have 10(4) to 10(5) fold less activity in proliferation assays with 7TD1 murine plasmacytoma cells and did not competitively inhibit the stimulatory activity of rIL6-full. In addition, like rIL6-full, rIL6-alt had antiproliferative activity toward M1 murine myeloblast cells and was 10-200-fold less active than rIL6-full. In contrast, in assays with human HL60 promyelocytic leukemia cells, rIL6-alt had greater antiproliferative activity than rIL6-full and more strongly upregulated phagocytosis as well as surface expression of the differentiation antigen CD11b. rIL6-full and rIL6-alt upregulated the level of lysozyme mRNA in HL60 cells approximately equally. These findings suggest that IL6-alt, which lacks amino acid residues encoded by the second exon of the gene, is not a natural inhibitor of IL6-full but may be relatively tissue specific and may play a role in modulation of hematopoietic cell growth and differentiation.
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PMID:Hematopoietic differentiation activity of a recombinant human interleukin-6 (IL-6) isoform resulting from alternatively spliced deletion of the second exon. 1039 9

A primary intracerebral plasmacytoma was identified in a 7-year-old spayed female Boston Terrier. Grossly, a well-demarcated, 2 cm in diameter, roughly spherical tumor was in the rostral aspect of the left cerebral hemisphere. Histologically, the neoplasm was composed of sheets of round cells with distinct plasmacytoid features and marked anisocytosis and anisokaryosis. Cells were positive for vimentin, CD18, CD79a, and lambda light-chain, and negative for kappa light chain, cytokeratin, lysozyme, glial fibrillary acidic protein, and S100 protein. Clonally rearranged B-cell antigen receptor genes were detected by PARR (polymerase chain reaction for antigen receptor rearrangements), confirming clonal proliferation of B lymphocytes. Although primary solitary intracerebral plasmacytoma is rare in dogs and other species, it should be included in the differential diagnosis for central nervous system round-cell neoplasms. Clonality testing can be utilized to support the histological diagnosis of this neoplasm type.
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PMID:Solitary intracerebral plasmacytoma in a dog: microscopic, immunohistochemical, and molecular features. 1942 98