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Biomedical subjects

B A Sebek

Publications and source records attributed to B A Sebek.

At least 37 records · Page 2Linked to original sources

Antigenic phenotype of splenic hairy cells.

Hairy cell leukemia, a distinct clinical and morphologic lymphoproliferative disorder, is characterized by the proliferation of mononuclear cells of uncertain derivation. Attempts to identify the cell of origin have used studies either of functional capabilities or of membrane/cytoplasmic antigens. Only a few cases have been studied via monoclonal antibodies. Frozen sections of splenic tissue involved with hairy cell leukemia were studied with a variety of monoclonal antibodies having specificity for differentiation antigens using the avidin-biotinylated peroxidase complex technique. Conventional direct and indirect immunohistochemical study was used for immunoglobulin heavy and light chains. In all but one case, the neoplastic cells expressed monoclonal immunoglobulin. Although T cells were identified in persisting periarteriolar sheaths and occasionally admixed with red blood cells in pseudosinuses, phenotypic expression of intrathymic or peripheral T cell antigens by the proliferating neoplastic cells was not observed. Conversely, expression of B1 and HLA-Dr antigens by splenic hairy cells was documented in all 10 cases. Hairy cell leukemia cells did not express either monocyte antigens (M1 and MO2) or the antigens expressed by early (J5) and intermediate (B2) B cells or plasmacytoid lymphocytes and plasma cells (T10). These immunohistochemical results with monoclonal antibodies provide further evidence that hairy cell leukemia is characterized by a combination of antigens peculiar to mature B lymphocytes.

Antibodies, Monoclonal↗

Immunoregulatory Leu-7+ and T8+ lymphocytes in B-cell follicular lymphomas.

Lymphocyte subpopulations were profiled in lymph nodes and tonsils showing follicular hyperplasia and in follicular lymphomas with monoclonal antibodies on frozen tissue sections. Immunoregulatory lymphocyte subsets identified with T8 and Leu-7 monoclonal antibodies were quantified within the follicular centers (FC) of the nonneoplastic tissue and neoplastic follicles of the lymphomas with an optical grid defining a unit surface area (USA) of 0.04 mm2. T8+ cells were essentially confined to the interfollicular areas, with a few cells occupying the FC of the nonneoplastic specimens (mean, two and five cells/USA for tonsils and benign lymph nodes, respectively). Although lymphomas exhibited a similar pattern of distribution of T8+ cells, 17 T8+ cells/USA were observed in the follicular small cleaved cell (FSCL) group and eight T8+ cells/USA within the follicular mixed small cleaved and large cell (FML) group. Leu-7+ cells were almost entirely confined to the FC of the nonneoplastic tissues and increased (mean, 17 and 19 cells/USA for tonsils and benign lymph nodes, respectively) compared with the T8+ population. Variable distributions of Leu-7+ cells were found in the FSCL group, with a mean of 16 cells/USA. Very few Leu-7+ cells were present in the FML group. Natural killer cells and/or cytotoxic/suppressor T lymphocytes may play an immunoregulatory role in modulating the growth of follicular lymphomas.

Antibodies, Monoclonal↗

Immunohistologic cellular phenotypes of lymphoproliferative disorders. Comprehensive evaluation of 564 cases including 257 non-Hodgkin's lymphomas classified by the International Working Formulation.

The plethora of classifications for non-Hodgkin's lymphomas (NHLs) and controversy regarding the merits of the individual classification schemes has led to the articulation of an International Working Formulation for NHL classification by a working group sponsored by the National Cancer Institute. This classification is based on both architectural and cytologic features and has been shown to have clinical relevance, but it is not an immunologic approach. With the use of frozen sections and both polyclonal and monoclonal antibodies, a comprehensive immunohistologic study was made of 564 biopsy specimens 1) for determination of the utility of the principle of monoclonality in differentiating benign from malignant lymphoproliferative disorders, 2) for definition of the immunohistochemical phenotypes of histologically benign and malignant cellular proliferations, and 3) for evaluation of the immunologic phenotype of 257 non-Hodgkin's lymphomas classified by the International Working Formulation. Two hundred seven "reactive benign" lymphoproliferations demonstrated polyclonal immunostaining. Monoclonal kappa light chain immunostaining was demonstrated in 3 of 4 cases classified as atypical hyperplasia, two of which had coexistent NHL or subsequently developed overt NHL. Frozen tissue sections were found to be essential for demonstration of immunoglobulin and glycoprotein membrane antigens. The results of immunohistochemical studies were readily integrated with the International Formulation. Although diffuse mixed and small lymphocytic lymphomas were immunologically heterogeneous (both T- and B-cell), follicular lymphomas were invariably of B-cell type, and immunoblastic lymphomas originating from homogeneous T- and B-cell populations were identified.

Antibodies, Monoclonal↗

Immunohistochemistry of fresh-frozen lymphoid tissue with the direct immunoperoxidase technic.

Recent evidence suggests that immunofluorescence is superior to immunohistochemistry for the study of lymphomas, since the latter procedure often results in identification of polyclonal cytoplasmic immunoglobulins or negative immunostaining in non-Hodgkin's lymphomas marking monoclonal with immunofluorescence. However, immunohistochemical studies are usually applied to paraffin-embedded tissues. A modified direct immunoperoxidase procedure using fresh-frozen cryostat tissue sections, short incubation with peroxidase-labeled antikappa and antilambda antisera, and chromogens chemically unrelated to benzidine was developed. Non-Hodgkin's lymphomas previously characterized by direct immunofluorescence showed monoclonal surface membrane-associated light chains outlining each neoplastic cell. Follicular (nodular) lymphomas were characterized by monoclonal light chains in neoplastic nodules with compressed negative or polyclonal rims. Diffuse non-Hodgkin's lymphomas demonstrated diffuse individual cellular monoclonal staining. Five normal lymph nodes showed polyclonal immunostaining of follicular centers. The immunostained slides resulting from this procedure are permanent preparations amenable to counterstaining.

Frozen Sections↗

Extraskeletal Ewing's sarcoma arising in the nasal fossa. Light- and electron-microscopic observations.

Extraskeletal Ewing's sarcoma is a rare malignant neoplasm that has been reported to involve most frequently the soft tissues of the lower extremity and the paravertebral region. This report describes the clinicopathologic features of a polypoid tumor arising from the soft tissue of the left middle turbinate in a 39-year-old man. Histologically, the neoplasm was composed of small, round to oval cells with scant cytoplasm that were arranged in sheets with multiple areas of hemorrhage and necrosis. The cytoplasm contained glycogen granules. Electron microscopy revealed cells with scant cytoplasm containing glycogen rosettes and a paucity of organelles. These histologic and ultrastructural features are those of both skeletal and soft-tissue Ewing's sarcoma.

Adult↗

Tissue immunomicroscopic evaluation of monoclonality of B-cell lymphomas: comparison with cell suspension studies.

A series of 80 tissues removed from patients having a variety of lymphoproliferative disorders were comparatively studied by cell suspension and cryostat frozen section tissue immunomicroscopic technics. Of 39 cases of non-Hodgkin's lymphomas studied by cell suspension, only 18 had surface immunoglobulins (SIg) markers consistent with monotypia (46%). Conversely, immunohistochemistry showed 18 cases (92%). Among the 18 cases in which there was no correlation between immunohistochemistry and cell suspension studies (46%), a variety of cytologic variants of non-Hodgkin's lymphomas was recognized, including nodular poorly differentiated lymphocytic lymphoma, nodular large cell lymphoma, and a soft tissue plasmacytoma. The lack of correlation between the two technics may be due to several different mechanisms, including the selective enrichment of the suspension by nonneoplastic cell populations resulting in a sampling artifact, the disappearance of endogenous SIg in large or plasmacytoid lymphocytes, and the presence of membrane-bound exogenous polyclonal SIG. Immunohistochemistry represents a reliable, simple technic for establishing monotypia in non-Hodgkin's B-cell lymphomas.

Antibodies, Neoplasm↗

Nasal tuberculosis: a forgotten entity.

Tuberculosis of the nose has become so infrequent that it is virtually a forgotten disease entity among younger practitioners in this country. Nevertheless, it can occur in all segments of our population and may present a confusing diagnostic problem. Two cases of primary nasal tuberculosis have been diagnosed and treated at The Cleveland Clinic Foundation since 1975. The differential diagnosis of nasal granulomatous disease usually includes Wegener's granulomatosis, midline malignant reticulosis, and sarcoidosis. We point out the necessity of including tuberculosis in this differential diagnosis. The definitive work-up and treatment are also discussed.

Biopsy↗

The contrecoup phenomenon. Reappraisal of a classic problem.

We describe briefly and comment upon the salient strengths and limitations of the major published theories that purport to explain the mechanism of contrecoup cerebrocortical contusions. Through the application of mechanical principles, we then present a modification, clarification, and expansion of selected aspects of several theories. Our final formulation emphasizes the injurious potential of nonuniform compressive stress and the relationship between brain lag and rotationally induced injury. The resulting theory remains faithful to the laws of physics while explaining the location and distribution of cerebrocortical contusions opposite the site of a moving head impact.

Biomechanical Phenomena↗

Acute nonlymphocytic leukemia in patients receiving chemotherapy for nonmalignant diseases.

The occurrence of acute leukemia in patients receiving chemotherapeutic agents for malignant disease has been well established. Recent reports have suggested that chemotherapeutic drugs used to treat inflammatory conditions may have an oncogenic potential. From 1969 to 1977, 11 patients with a variety of collagen-vascular diseases who developed acute nonlymphocytic leukemia were seen at the Cleveland Clinic. Rheumatoid arthritis was the most common underlying disease, in addition to giant cell arteritis, polyarteritis nodosa, chronic glomerulonephritis, and scleroderma. All patients were treated with alkylating agents, and 10 of the 11 received multiple cytotoxic agents. According to the French-American-British classification there were six examples of M4 (myelomonocytic leukemia), with single examples of M1 (myeloblastic leukemia without maturation), M2 (myeloblastic leukemia with maturation), M5a (monocytic leukemia, poorly differentiated), M5b (monocytic leukemia, differentiated), and M6 (erythroleukemia). Cytogenetic studies were abnormal in five patients studied, showing varying degrees of aneuploidy. All patients died, and the mean duration of time from the diagnosis of leukemia to death was four and one-half months, with only one complete remission.

Arthritis, Rheumatoid↗

Idiopathic infarction of intraabdominal lymph nodes. A cause of fever of unknown origin.

Infarcted peribiliary lymph nodes were found at laparotomy in a 56-year-old man who had a fever of unknown origin and transient abdominal pain. Despite thorough clinical and laboratory investigation, a cause was not demonstrated. A review of the reported cases of idiopathic or spontaneous lymph node infarction revealed a clinical presentation characterized by the sudden appearance of a painful mass, often associated with otherwise unexplained fever. Most clinical laboratory test results were negative. Although the pathogenesis is not known, histologic changes in involved lymph nodes are indistinguishable from those produced experimentally by occlusion of the vascular supply of lymph nodes. The histologic differential diagnosis includes lymphoma, metastatic carcinoma, vasculitis, and infection.

Abdomen↗

Immunohistochemistry of Warthin's tumor.

This study describes results of fresh-frozen immunohistochemistry applied to two typical Warthin's tumors. Polyclonal follicular center cell staining and an apparent reduction in the number of T-lymphocytes were found. These observations tend to support the concept that the lymphoid infiltrate in Warthin's tumor represents a reactive cellular proliferation.

Adenolymphoma↗

Malignant histiocytosis. Ultrastructural and immunocytochemical characterization.

The immunohistochemical and ultrastructural characteristics of involved lymph nodes from four patients with typical clinical and histopathologic features of malignant histiocytosis are reported. The neoplastic cells in all four cases had numerous irregular surface projections and pseudopodia, as well as lobulated or biolobed nuclei with macronucleoli. The cytoplasm contained many lysosomes, mitochondria, and polyribosomes, and displayed evidence of phagocytosis. Langerhans' granules were not identified. The ultrastructural features in the four cases were similar, effectively excluded an epithelial origin in each instance, and delineated morphological characteristics common to neoplastic macrophages. Intracytoplasmic muramidase (CM), an enzyme marker essentially restricted to cells of myeloid and true histiocytic origin, was identified with the unlabeled immunocytochemical technique and was strongly positive in neoplastic histiocytes at all stages of differentiation. Thus, fine structural features and the presence of CM are useful confirmatory studies in the diagnosis of malignant histiocytosis.

Cell Membrane↗

Expression of monocytic--histiocytic cytochemical markers in epithelial neoplasia.

The diagnosis of malignant histiocytosis is usually based upon typical light microscopic features of the neoplasm. Supplementary cytochemical and immunologic features have been suggested as typical of malignant histiocytosis. The present study was prompted by an unusual erythropagocytic hepatocellular carcinoma having immunologic and cytochemical markers suggesting mononuclear phagocytic origin. Twenty-four neoplasms of unquestionable epithelial origin were prospectively evaluated for activity of alpha-naphthyl acetate esterase, a cytochemical marker useful in distinguishing between the non-Hodgkin's lymphomas and malignant histiocytosis. The epithelial tumors represented a broad spectrum of tissue origins and consistently demonstrated alpha-naphthyl acetate esterase activity. Thus, erythrophagocytosis and alpha-naphthyl acetate esterase positivity may be misleading in the unusual instance in which the histopathologic differential diagnosis includes malignant histiocytosis and epithelial neoplasia. Ultrastructural assessment is useful in the exclusion of poorly differentiated carcinoma.

Carboxylic Ester Hydrolases↗