Use of a Dacron mesh coated pericardium for aortic augmentation.

A technique is described for aortic augmentation with Dacron mesh coated pericardial patch. This method avoids the use of synthetic graft material with the potential for weak adherence of pseudointima and microembolization. Hemostasis is improved and fibrous tissue ingrowth into the mesh prevents late aneurysm formation. The incorporation of the pericardial patch into the aortic wall and the normal endothelialization of the patch is documented after a 5-year follow-up.

Absence of bcl-2 major breakpoint region and JH gene rearrangement in lymphocyte predominance Hodgkin's disease. Results of Southern blot analysis and polymerase chain reaction.

Recent evidence suggests that nodular lymphocyte predominance Hodgkin's disease (NLPHD) is a distinct entity that may be related to progressively transformed germinal centers, abnormal B-lymphoid hyperplasia, and low-grade B-cell lymphoma. bcl-2 is a marker for the translocation t(14;18)(q32;q21), which occurs in most follicular-derived B-cell lymphomas. Eleven cases of NLPHD and 19 cases of Hodgkin's disease of nodular sclerosis (NSHD) and mixed cellularity (MCHD) type were analyzed for immunoglobulin JH gene rearrangement. bcl-2 translocation was determined with Southern blot analysis and the polymerase chain reaction using biotin labeled probes to the major breakpoint region and the alkaline phosphatase reaction. All cases of NLPHD were negative for JH gene rearrangement and bcl-2 translocation. Cases of NSHD and MCHD were similarly negative for bcl-2, although three cases exhibited clonal JH gene rearrangements. These results confirm that a clonal B-cell population is not detected in NLPHD. Cases of NLPHD differ from most low-grade follicular B-cell lymphomas in that they lack bcl-2 gene rearrangement and t(14;18) translocation at the major breakpoint region.

Polymerase chain reaction for bcl-2 in diagnostic lymph node biopsies.

bcl-2 is a marker for the translocation t(14;18)(q32;q21) indicative of follicular B-cell lymphoma. We studied 115 cases of lymphoproliferative disease with the polymerase chain reaction for bcl-2 oncogene using biotin and radiolabeled probes to the major breakpoint and minor cluster regions. Twenty-three percent of B-cell lymphomas were positive for bcl-2. These included 12 of 20 cases of nodular follicular center cell lymphoma (nine small cleaved cell, one mixed small and large cell, and two large cell types). bcl-2 translocation was detected in only three of 45 cases of diffuse B-cell lymphoma, and cases of AIDS-related malignant lymphoma, monocytoid B-cell lymphoma, and mantle zone lymphoma were all negative. Nonneoplastic lymphoid proliferations were negative for bcl-2 including nine cases of abnormal follicular hyperplasia from patients with acquired immunodeficiency syndrome (AIDS) and AIDS-related complex. Cases of T-cell lymphoma and five cases of Hodgkin's disease were also negative. The polymerase chain reaction for bcl-2 is a rapid, sensitive technique in the evaluation of follicular B-cell proliferations, and the use of biotinylated probes and the alkaline phosphatase reaction eliminates the requirement for radioactive reagents.

Immuno-ultrastructural localization of B-cell-specific monoclonal antibodies B1 and B2.

Monoclonal antibodies B1 and B2 are thought to recognize B-lineage restricted antigens, and have been used to define stages of B-cell maturation and characterize B-cell lymphomas. Immunostaining on cryostat sections has revealed a puzzling dendritic or extracellular pattern of staining for B2 within germinal centers and neoplastic follicles. In this study B1 and B2 are localized precisely on hyperplastic and neoplastic lymphoid tissues using immuno-ultrastructural techniques on cryostat sections, cell suspensions, and cell monolayers. B1 and B2 were localized to cell surfaces, including microvillous surface projections, on small and large transformed normal and neoplastic B lymphocytes. B2, in addition to staining in lymphoid cells, was localized to anastomosing cytoplasmic processes of dendritic histiocytes. These findings explain the apparently extracellular localization of B2 in cryostat sections and indicate that patterns of staining for B2 may represent a combination of staining on lymphoid cells and dendritic histiocytes.

Immunoultrastructural and morphometric analysis of B lymphocytes in human germinal centers. Evidence for alternate pathways of follicular transformation.

Monoclonal antibodies to B-cell differentiation antigens B1, B2, C3b, and Ia were used for ultrastructural characterization of B lymphocytes undergoing follicular transformation in human germinal centers. Morphologic alterations and morphometric parameters including form factor (FF) and nuclear contour index (NCI) were evaluated. Antibodies to B1, Ia, and C3b revealed uninterrupted linear surface membrane staining in B cells at various stages of transformation, while staining for B2 appeared as aggregates of gold particles localized to sites of antigen expression along the cell membrane. B cells with highly irregular or convoluted nuclei (NCI greater than 6.5) formed 3% of follicular lymphocytes and may explain the derivation of rare follicular center cell lymphomas with marked nuclear irregularity which mimic T-cell lymphomas histologically. Cleaved cells (NCI greater than or equal to 4.5) comprised 48% of the cellular population and were present at all stages of transformation. Results of morphometric studies suggest that small cleaved cells (centrocytes) and noncleaved cells transform to large lymphoid cells (centroblasts) along parallel lines, and without following the sequential differentiation pathway suggested by Lukes and Collins.

Involucrin in intraepithelial and invasive squamous cell carcinomas of the cervix: an immunohistochemical study.

Immunohistochemical staining for involucrin, a cytoplasmic protein synthesized during squamous maturation, was assessed in histologic sections from hysterectomy and cone biopsy specimens from patients with cervical neoplasia. In normal and condylomatous squamous epithelium, diffuse cytoplasmic staining was seen in the suprabasal layers, with no staining of the basal cells. Staining was absent in two cases of cervical intraepithelial neoplasia (CIN), grade III, in which the lesions were composed entirely of undifferentiated cells and markedly decreased in cases involving large numbers of basal cells. In 19 of 23 cases (83 per cent) of CIN, however, focal staining for involucrin was seen in large differentiated cells in the more superficial layers, and in two cases of keratinized CIN diffuse suprabasal staining was observed. Similarly, strong staining for involucrin was present in differentiated areas in one case of microinvasive squamous cell carcinoma and in 93 per cent of cases of infiltrating squamous cell carcinoma. These findings suggest that involucrin is a marker for maturation in cervical squamous epithelial neoplasms. Patterns of immunohistochemical staining for involucrin in keratinized dysplasia and differentiated squamous carcinomas should be taken into consideration if loss of involucrin staining is used as a criterion for neoplastic transformation of cervical epithelium, as has been proposed.

Immunoreactive neuron-specific enolase, bombesin, and chromogranin as markers for neuroendocrine lung tumors.

Sixty-four lung tumors were evaluated for the presence of immunoreactive neuron-specific enolase (NSE), bombesin (Bn), and chromogranin (Cg) to assess their value as markers for neuroendocrine cells in the histologic diagnosis of pulmonary neoplasms. Staining was correlated with the presence and density of neurosecretory granules (number of neurosecretory granules per unit cytoplasmic cross-sectional area) as determined by planimetry on electron micrographs. The cytoplasmic density of neurosecretory granules was significantly greater in the carcinoid tumors than in the small cell carcinomas (P less than 0.001). Neuron-specific enolase was localized in all of the neuroendocrine granule-bearing tumors but was also present in 57 per cent of the nonneuroendocrine carcinomas. Bombesin was present in 68 per cent of the neuroendocrine tumors and in less than 1 per cent of the nonneuroendocrine tumors. Staining for Cg appeared to correlate with the density of neuroendocrine granules, with staining in carcinoid tumors but no staining in small cell anaplastic carcinomas. A panel of antibodies may be required for the reliable identification of neuroendocrine lung tumors by immunohistochemical techniques.

Distribution of T-cell phenotypic subsets and surface immunoglobulin-bearing lymphocytes in lymph nodes from male homosexuals with persistent generalized adenopathy: an immunohistochemical and ultrastructural study.

Lymph nodes from homosexual men with persistent generalized adenopathy were evaluated for distribution of T-cell phenotypic subsets and surface immunoglobulin(SIg)-bearing lymphocytes. Electron microscopy revealed tubulovesicular structures within lymphocytes but no multivesicular rosettes. Eight to 33 per cent of the lymphocytes within germinal centers were suppressor T cells, compared with germinal centers from control lymph nodes, in which these cells were rare (P = 0.002). Significantly greater percentage of suppressor/cytotoxic T lymphocytes were also present in the paracortex and follicular mantles of lymph nodes from the homosexual group (P = 0.002 and 0.007, respectively). Percentages of helper T lymphocytes were significantly decreased in germinal centers (P = 0.008) and paracortical regions (P = 0.002). Florid follicular hyperplasia with aberrations in follicular architecture was the most common histologic pattern, but one node with diffuse hyperplasia and subtotal effacement of architecture revealed depletion of SIg-bearing lymphocytes and increased numbers of suppressor T cells. Reversed helper-to-suppressor T-cell ratios in lymph nodes from homosexuals with generalized adenopathy may be related to viral infection and contribute to immune deficiency in this group.

Involucrin in squamous and basal cell carcinomas of the skin: an immunohistochemical study.

Involucrin is a precursor of cross-linked protein of human stratum corneum, and its appearance in the upper layers of the epidermis is a function of the normal differentiation of the keratinocyte. Cases of basal cell and squamous cell carcinoma were evaluated for the presence of involucrin using immunoperoxidase techniques on paraffin sections. Basal cell carcinomas were negative for involucrin with staining restricted to squamous horn cysts, while squamous cell carcinomas stained strongly, particularly in large keratinized cells. Cases of squamous cell carcinoma in situ (Bowen's disease) revealed increased staining for involucrin with staining of dyskeratotic cells at all levels in the epithelium. Abnormal patterns of staining were also noted in non-neoplastic epidermis adjacent to carcinomas. Immunohistochemical staining for involucrin identifying abnormal or premature keratinization is a sensitive marker for dyskeratosis in squamous epithelia and may have applications in the histopathologic evaluation of skin specimens.

Localized fibrous mesothelioma: an immunohistochemical and electron microscopic study.

The absence of keratin staining in tumor cells from localized fibrous mesotheliomas in both paraffin-embedded and frozen sections with sensitive peroxidase-antiperoxidase and avidin-biotin techniques is described. In addition ot the absence of staining for whole-stratum corneum keratin proteins, sections were negative for keratins of different molecular weights (45, 55, and 63 kilodaltons) that are characteristically present in mesothelial cells. Ultrastructurally, the cells most closely resembled mesenchymal cells of the fibroblastic type. These findings are in accordance with recent theories that relate the derivation of localized fibrous mesotheliomas to nonmesothelial cells, including subpleural connective tissue. Based on differences in immunohistochemical staining, the tumors appear to be unrelated to diffuse malignant mesotheliomas.

Peripheral T cell lymphoma (immunoblastic sarcoma of T cell type): an immuno-ultrastructural study.

Use of monoclonal antibodies directed against T cell antigens for the phenotypic characterization of neoplastic lymphoid cells in peripheral T cell lymphomas is described. Studies of cryostat sections revealed the distribution of T cell subsets in nodal and extranodal infiltrates, and immuno-ultrastructural techniques demonstrated discrete localization of T cell antigens to the cytoplasmic membranes of neoplastic cells. Although histologically similar, the tumors appeared heterogeneous as to their immunologic phenotype, with the majority demonstrating markers for T helper/inducer lymphocytes.

Keratins of different molecular weight in exfoliated mesothelial and adenocarcinoma cells--an aid to cell identification.

Keratin profiles of exfoliated mesothelial and adenocarcinoma cells were determined using antisera to different molecular weight keratins (45, 46, 55, 63 kdaltons) and the immunoperoxidase technic. Most metastatic adenocarcinomas in effusions stained for low (45, 46 kdaltons) and intermediate (55 kdaltons) molecular weight keratins but were negative for 63 kdalton keratin. In contrast, most reactive and malignant mesothelial cells in effusions stained strongly for 63 kdalton keratin and keratins of lower molecular weight. This is the first report of high molecular weight (greater than 60 kdaltons) keratin in exfoliated cells of nonepidermal origin. Differences in staining for 63 kdalton keratin between mesothelial and adenocarcinoma cells may help to distinguish these cells in effusions.

Involucrin in lung tumors. A specific marker for squamous differentiation.

Involucrin is a precursor of the cross-linked envelope protein or marginal band present in human stratum corneum. This study uses immunohistochemical techniques for localization of involucrin in histologic sections from 91 lung tumors in order to evaluate the usefulness of involucrin as a tumor marker in lung neoplasms. Although involucrin is absent from bronchial epithelium, it is expressed in cultured tracheal epithelial cell colonies and in bronchial mucosa with squamous metaplasia. Involucrin was present in all 25 cases of squamous and adenosquamous carcinoma. Staining was focal in 12 cases of squamous cell carcinoma and was most marked in the larger neoplastic cells in the center of squamous cell nests. Only two of 20 cases of adenocarcinoma revealed focal staining for involucrin, and these cases may represent adenosquamous variants. Six of 12 cases of large cell undifferentiated carcinoma stained for involucrin, indicating squamous differentiation, and seven cases of malignant mesothelioma were negative. Isolated involucrin-positive cells were present in two of 16 cases of small cell anaplastic carcinoma and one of 11 carcinoid tumors, identifying variants of neuroendocrine tumors with dual differentiation. Patterns of localization of involucrin in paraffin and frozen sections were compared with staining for cytokeratins in parallel sections. Immunohistochemical localization of involucrin comprises a specific marker for squamous differentiation in lung tumors.

Keratin in human lung tumors. Patterns of localization of different-molecular-weight keratin proteins.

In this immunohistochemical study, antiserums to different molecular weight keratin proteins (45kd, 46kd, 55kd, and 63kd) were utilized to determine the profiles of keratin proteins present in a variety of pulmonary neoplasms. Different histologic types of lung carcinoma exhibited different patterns of keratin staining. Squamous cell carcinomas stained strongly for 45K, 46K, and 55K keratin, with staining for 63K restricted to areas or individual cells with cytoplasmic keratinization. Adenocarcinomas showed variable, generally weak staining for 45K, 46K, and 55K keratin and were uniformly negative for 63K keratin both in frozen and paraffin sections. Mesotheliomas and reactive mesothelial cells, by contrast, stained positively for 63K keratin in addition to keratins of lower molecular weights. Differences in staining for 63K keratin between mesothelioma and adenocarcinoma may have diagnostic application. Moreover, individual cytokeratins may serve as markers of tumor differentiation and provide information as to the origin of neoplastic cells.