Toru Takenaka

Cyclic mechanical stretch stress increases the growth rate and collagen synthesis of nucleus pulposus cells in vitro.

STUDY DESIGN A rabbit model designed to investigate the effects of applied cyclic tensile stress on the cell division rate and the collagen synthesis in the rabbit nucleus pulposus cells in vitro. OBJECTIVE To evaluate the effects of mechanical stress on nucleus pulposus cells, thus adding to the understanding of the adaptation of the intervertebral disc to mechanical stress. SUMMARY OF BACKGROUND DATA Intervertebral disc cells in vivo are exposed to a multitude of physical forces during physical motion. Although it is known that in intervertebral disc disease, a common pathway of disc degeneration is mechanical stress on the nucleus pulposus or the anulus fibrosus or both, the underlying mechanism has been less well defined. METHODS Nucleus pulposus cells were isolated from 4-week-old Japanese white rabbits. These cells were subjected to the mechanical cyclic stretch stress using a computerized, pressure-operated instrument that physically deformed the cells. The DNA synthesis rate, collagen synthesis rate, and cell cycle progression were measured. RESULTS Cyclic tensile stretch increased the DNA synthesis rate in nucleus pulposus cells and in the population of cells in the S phase of the cell cycle during 1 to 2 days of subjugation to stress. Cyclic tensile stretch also increased collagenous protein synthesis in nucleus pulposus cells during 1 to 4 days of stress. CONCLUSIONS Mechanical stress on nucleus pulposus cells promotes the proliferation of cells and alters the properties of intervertebral disc cells. This study may reflect the adaptation of the intervertebral disc to increased motion and stress.

Spontaneous Complete Regression of High Grade Non-Hodgkin's Lymphoma Morphologic, Immunohistochemical, and Gene Amplification Analyses

Background. Spontaneous regression of non‐Hodgkins lymphoma, occasionally reported in low grade groups, is a rare phenomenon in high grade groups. Clonal proliferation has not been confirmed in the majority of reported cases. In this woman, age 58 years, who had been diagnosed as having high grade immunoblastic lymphoma after excision of a single cervical lymph node, the remaining bilateral cervical, inguinal, and axillary adenopathy regressed completely without any cytotoxic treatments 22 days after biopsy. At the time of this writing, the patient has been free of disease for 24 months.

UCHL1‐positive extranodal lymphoma resembling multiple lymphomatous polyposis of the gastrointestinal tract

Histopathologic and immunohistochemical studies were done on paraffin sections from a patient with alimentary tract lymphoma resembling multiple lymphomatous polyposis of the gastrointestinal tract (MLP). Diffuse, but not follicular, proliferation of medium‐sized lymphoid cells was noted in the polypoid lesions of the alimentary tract, peripancreatic lymph nodes, spleen, liver, and bone marrow. These cells possessed a T‐cell‐related antigen (UCHL1), but were negative for the B‐cell‐related and myeloid cell‐related antigens examined. Because neoplastic cells in MLP are usually of B‐cell origin, the current case will provide important information on the relation between phenotypes and morphologic patterns of proliferation.

Hodgkin's disease in hairy cell leukemia: Phenotypic characterization of neoplastic cells

A case of Hodgkins disease (HD) in a patient with long‐standing hairy cell leukemia (HCL) is reported. The diagnosis of HCL was confirmed by clinical features (chronic illness with marked splenomegaly) and hematopathologic findings (increase of characteristic hairy cells with tartrate‐resistant acid phophatase activity in peripheral blood and bone marrow). Cervical lymphadenopathy first appeared 6 years after the diagnosis of HCL, and histologic features of the node were characteristic of HD. As it was possible that the neoplastic cells of both lesions might have originated from a single clone, their phenotypic features were defined. The hairy cells were found to bear surface immunoglobulin, receptors for complement components, leukocyte common antigen, and antigen defined by LN‐1 monoclonal antibody, whereas lymph node lesion was characterized as HD because the Reed‐Sternberg‐like cells were positive for Leu M1 antigen, lysozyme, alpha‐1‐antitrypsin, and nonspecific cross‐reacting antigen. Since there was no evidence indicating a common clonal origin, it is more likely to consider that both lesions are derived from different clones.

Extranodal lymphoma terminating in acute leukemia associated with igd monoclonal gammopathy a case report

A case of malignant lymphoma associated with IgD monoclonal gammopathy is described. Orbital and testicular tumors were observed, while peripheral lymphadenopathy was absent. Neoplastic lymphoid cells appeared in peripheral blood, bone marrow, and pleural effusion with progression of the disease. Analysis of the serum suggested “unreactive” light chain determinants in monoclonal protein. in immunohistochemical studies and in vitro experiments, it was confirmed that IgD monoclonal gammopathy was directly related to the neoplastic cells. These unusual findings suggest that neoplastic changes such as neoplasms of other B‐cell systems may occur at various stages in the differentiation and maturation of IgD‐forming B‐cell lineage.

Lymph node involvement in chronic neutrophilic leukemia. An immunohistochemical study.

An immunohistochemical study was performed on autopsy material from a patient with chronic neutrophilic leukaemia (CNL) using antibodies against various cell lineage-related antigens. Proliferation of immature neutrophils with occasional clusters of erythroblasts and megakaryocytes were noted in the retroperiotoneal lymph nodes, spleen, and kidneys as well as in the bone marrow. Predominance of immature neutrophils in the lymph nodes suggested the emergence of a blast crisis, although there was no increase of blasts in the peripheral blood. Since immature myeloid cells are difficult to distinguish from malignant lymphoid cells on tissue sections, we suggest that immunohistochemical identification of cell lineage-related molecules on these cells is necessary for the more accurate interpretation of lymph node lesions in myeloid neoplasms.

IMMUNOBLASTIC LYMPHADENOPATHY-LIKE T-CELL LYMPHOMA WITH MULTIPLE CUTANEOUS AND VISCERAL INVOLVEMENTS

Morphologic and immunological findings found in a patient with immunoblastic lymphadenopathy (IBL)‐like T‐cell lymphoma (IBL‐T) are presented. Though the initial clinical features were suggestive of IBL, multiple cutaneous and visceral tumors appeared later in his course. The cutaneous lesion is considered to be unique, because the neoplastic T cells with suppressor/cytotoxic (S/C) phenotype showed focal epidermotropism, resulting in necrosis and ulceration of the overlying epidermis. An interesting feature in IBL‐T is the frequent association of polyclonal hypergammaglobulinemia, yet the neoplastic T cells show S/C phenotype. Since la‐like antigen was expressed on the neoplastic T cells, it is stressed that antigen‐presenting and contrasuppressor cells should also be included in the cell populations which have a possibility to be a normal counterpart of IBL‐T.

Monoclonal IgM-secreting neoplasms. Clinical and morphologic heterogeneity.

Two patients with monoclonal IgM‐secreting neoplasms are presented. Though both patients could be diagnosed as Waldenströms macroglobulinemia, the clinicopathologic features were quite contrastive. Most neoplastic cells in Case 1 showed lymphocytic morphology with rather leukemic process, while those in Case 2 were highly polymorphic with solid proliferation. The clinical and morphologic heterogeneity in these cases and cases in the literature is discussed, and the possible requirement to establish a system for the subclassification of IgM‐secreting neoplasms is insisted.