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Biomedical subjects

S M Hsu

Publications and source records attributed to S M Hsu.

At least 55 records · Page 3Linked to original sources

Activation of a 15-kDa endonuclease in hypoxia/reoxygenation injury without morphologic features of apoptosis.

Hypoxia/reoxygenation is an important cause of tissue injury in a variety of organs and is classically considered to be a necrotic form of cell death. We examined the role of endonuclease activation, considered a characteristic feature of apoptosis, in hypoxia/reoxygenation injury. We demonstrate that subjecting rat renal proximal tubules to hypoxia/reoxygenation results in DNA strand breaks and DNA fragmentation (both by an in situ technique and by agarose gel electrophoresis), which precedes cell death. Hypoxia/reoxygenation resulted in an increase in DNA-degrading activity with an apparent molecular mass of 15 kDa on a substrate gel. This DNA-degrading activity was entirely calcium dependent and was blocked by the endonuclease inhibitor aurintricarboxylic acid. The protein extract from tubules subjected to hypoxia/reoxygenation cleaved intact nuclear DNA obtained from normal proximal tubules into small fragments, which further supports the presence of endonuclease activity. Despite unequivocal evidence of endonuclease activation, the morphologic features of apoptosis, including chromatin condensation, were not observed by light and electron microscopy. Endonuclease inhibitors, aurintricarboxylic acid and Evans blue, provided complete protection against DNA damage induced by hypoxia/reoxygenation but only partial protection against cell death. Taken together, our data provide strong evidence for a role of endonuclease activation as an early event, which is entirely responsible for the DNA damage and partially responsible for the cell death that occurs during hypoxia/reoxygenation injury. Our data also indicate that in hypoxia/reoxygenation injury endonuclease activation and DNA fragmentation occur without the morphological features of apoptosis.

Animals↗

Bilateral endobronchial non-Hodgkin's lymphoma.

Pulmonary involvement with non-Hodgkin's lymphoma, while well recognized, is less common than with Hodgkin's lymphoma. Endobronchial non-Hodgkin's lymphoma is even rarer and usually occurs in the presence of disseminated disease. We present a case of bilateral endobronchial non-Hodgkin's lymphoma.

Aged↗

Autocrine and paracrine functions of cytokines in malignant lymphomas.

Cytokines play important roles in the pathogenesis of lymphomas via an autocrine or a paracrine mechanism, or both. The characteristic clinical and histopathological features of malignant lymphomas may be due in part to elevated serum or tissue levels of cytokines. Determination of the effects of cytokines on the growth or differentiation of lymphoma cells is often complicated by the fact that more than one cytokine is responsible, and by the failure of anti-cytokine antibodies or antisense oligonucleotides to block the proliferation in vitro of lymphoma cells. However, it appears that IL-6 and/or IL-9 may play a prominent role in the tumor cell proliferation of Hodgkin's disease (HD), anaplastic large-cell lymphoma, or immunoblastic lymphoma. IL-6 may also be responsible for the plasmacytoid differentiation of lymphoma cells in polymorphic immunocytoma. The histopathological changes as a result of paracrine effects are most noticeable in HD. The malignant (H-RS) cells of HD have been shown to express IL-1, IL-5, IL-6, IL-9, TNF-alpha, M-CSF, TGF-beta, and CD80, and, less frequently, IL-4 and G-CSF. These cytokines may be responsible for the increased cellular reaction and fibrosis observed in tissues involved by HD and for the immunosuppression found in patients with HD. In contrast to H-RS cells, most non-HD lymphoma cells do not produce cytokines in excess amounts and reveal only a minimal cellular reaction. Exceptions include T-cell-rich B-cell lymphoma, angiocentric T-cell lymphoma, and angio-immunoblastic lymphadenopathy (AILD-like T-cell lymphoma. IL-4 is responsible for the T-cell reaction in T-cell-rich B-cell lymphoma, whereas IL-6 accounts for the plasma cell reaction in AILD-type T-cell lymphoma. The authors extensively review the role of cytokines in lymphomas because this may lead to major advances in the understanding of the molecular processes involved in the histopathogenesis of lymphomas.

Cytokines↗

The nature of Reed-Sternberg cells: phenotype, genotype, and other properties.

The most recent sophisticated investigations have provided new and revealing but also contradictory and controversial informaiton on the biological nature and the cellular origin of Hodgkin and Reed-Sternberg (H-RS) cells. Immunophenotypic analyses have shown consistent expression of CD15, CD30, CD74, and HLA-Dr antigens, but generally lack of T- or B cell-associated markers in H-RS cells. The H-RS cells are also devoid of many monocyte/macrophage-associated antigens. Molecular genetic studies have demonstrated heterogeneous findings with respect to rearrangements of T-cell receptor and immunoglobulin genes. Only a small percentage of the cases have rearrangements; this cannot always be attributed to the threshold of sensitivity of the method and/or the scarcity of the malignant cells in tissues examined. The H-RS cells do not express transcription factors such as BSAP, TCF-1, and GATA-3, known to be associated with lymphoid cells. It appears that evidence to support a lymphoid origin for H-RS cells is still lacking. On the contrary, the mechanism responsible for the unique clinical and histopathologic alterations associated with this disease has become clear. The H-RS cells have been shown to secrete IL-1, IL-5, IL-6, IL-9, TNF-a, M-CSF, and TGF-b, and, less frequently, IL-4 and G-CSF. These cytokines are likely to be responsible for the increased cellular reaction and fibrosis observed in tissues involved by HD and for the immunosuppression in patients with HD. Like most lymphomas, the etiology or pathogenesis of HD remains unknown. The Epstein-Barr virus (EBV) genomes are clonally integrated in the H-RS cells of about half the cases. The significance of these findings, whether EBV is a causative agent or an epiphenomenon, remains to be elucidated.

Gene Expression Regulation, Neoplastic↗

Abundant expression of transforming growth factor-beta 1 and -beta 2 by Hodgkin's Reed-Sternberg cells and by reactive T lymphocytes in Hodgkin's disease.

The depressed cellular immunity observed in patients with Hodgkin's disease (HD) has been attributed to production of transforming growth factor (TGF)-beta or TGF-beta-like substances by Hodgkin's Reed-Sternberg (H-RS) cells. The TGF-beta produced by L-428 cells (an H-RS cell line) is a 130-kd molecular weight glycoprotein that apparently differs from the TGF-beta (molecular weight, 25 kd) produced by most lymphoid and hematopoietic cells. Among several distinct types of TGF-beta that have been purified, only TGF-beta 1 and TGF-beta 2 have thus far been identified in hematopoietic cells. By using monoclonal antibodies (1D11 and 3C7) and oligonucleotide probes specific for TGF-beta 1 and TGF-beta 2, were confirmed that a cultured H-RS cell line, KM-H2, can produce both TGF-beta types, whereas another line, HDLM-1, produces only TGF-beta 1. Despite the abundance of mRNA in both of these cells, only small amounts of TGF-beta activity were detected, probably because of rapid degradation of TGF-beta 1 mRNA by specific nuclease. No degraded TGF-beta 2 RNA products were observed in KM-H2 cells. The TGF-beta produced by both types of H-RS cells had a molecular weight of approximately 25 kd. In tissues expression of TGF-beta was observed in a small portion (30%) of H-RS cells in 16 of 20 cases examined. A large number of small to medium-sized lymphoid cells (T lymphocytes) in tissues involved by HD also were positive for TGF-beta. These results indicate that there is functional heterogeneity among H-RS cells, and that H-RS cells are not the only source of TGF-beta in tissues involved by HD. Hodgkin's Reed-Sternberg cells are known to secrete several other cytokines, including interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha. These cytokines could be responsible for the increased number of T lymphocytes in tissues involved by HD. Furthermore, T lymphocytes can respond to IL-1 and IL-6 secreted by H-RS cells by increasing their production of TGF-beta. Abundant expression of TGF-beta by T lymphocytes was not observed in lymphoid tissues other than those involved by HD.

Base Sequence↗

Expression of interleukin-6 in Castleman's disease.

Although mixed forms of Castleman's disease (CD) may occur, two classically recognized forms are the angiofollicular (hyaline vascular [V]) variant and the plasma cell (P) variant. The two forms of CD differ greatly in their clinical and histopathologic manifestations. Plasma cell CD is characterized by the presence of hyperplastic germinal centers (GCs) and sheets of plasma cells in the interfollicular areas. In this study we demonstrated an abundant expression of interleukin-6 (IL-6) in most GC B cells and in the numerous immunoblastoid B cells in the mantle zone and interfollicular areas in CD-P. Patients with CD-P also have an elevated serum IL-6 level. The increased IL-6 production is responsible for the marked plasma cell infiltration in lymph nodes and bone marrow as well as for the elevated gammaglobulin level in serum. In contrast, CD-V is distinguished by the presence of atrophic GCs, which often are populated by cytologically atypical follicular dendritic reticulum (FDR) cells, as well as by sheets of T-zone plasmacytoid histiocytes and increased numbers of capillaries in the interfollicular areas. In contrast to the findings in CD-P, we did not observe significant expression of IL-6 in GC cells or in immunoblastoid cells in CD-V; this may account for the paucity of plasma cells in this form of CD. The reason for the atypical changes in FDR cells as well as the increases in T-zone plasmacytoid histiocytes and capillaries seen in CD-V are not known inasmuch as no cytokines, such as IL-1, IL-4, IL-6, IL-7, IL-8, IL-9, tumor necrosis factor-alpha, granulocyte-macrophage colony-stimulating factor, or granulocyte colony-stimulating factor, were detectable in tissues. It is possible that in CD-V the atypical change in FDR cells could lead to a disturbance of B-lymphocyte/FDR cell interaction and subsequently to poor development of GCs. The study clearly indicates that the histopathologic and clinical features of CD vary greatly depending on the capacity of activated B cells to produce IL-6. However, lack of IL-6 secretion by GC cells alone cannot explain the histopathologic alterations in CD-V.

Castleman Disease↗

Cytokines in malignant lymphomas: review and prospective evaluation.

Cytokines play important roles in the pathogenesis of lymphomas. Cytokines either can be produced or exert effects on neoplastic or reactive cells. The secretion of cytokines can provide growth advantages for tumor cells in either an autocrine or a paracrine fashion. An elevated serum or tissue level of cytokines can contribute to the clinical and histopathologic alterations associated with malignant lymphomas. The effects of cytokines on the histopathologic changes are most noticeable in Hodgkin's disease (HD). The malignant (Hodgkin's-Reed-Sternberg) cells in HD have been shown to secrete interleukin-1 (IL-1), IL-5, IL-6, IL-9, tumor necrosis factor-alpha, macrophage colony-stimulating factor, transforming growth factor-beta, and, less frequently, IL-4 and granulocyte colony-stimulating factor. These cytokines may be responsible for the increased cellular reaction and fibrosis observed in tissues involved by HD and for the immunosuppression in patients with HD. In contrast to Hodgkin's-Reed-Sternberg cells, most non-HD lymphoma cells do not produce cytokines in excess amounts. Exceptions include T-cell-rich B-cell lymphoma (IL-4), angioimmunoblastic lymphadenopathy-like T-cell lymphoma with plasmacytosis and hypergammaglobulinemia (IL-6), anaplastic large-cell lymphoma (IL-9), polymorphic immunocytoma (IL-6), and immunoblastic lymphoma (IBL) (IL-6). Some cytokines are involved in the unique cellular reactions in each of these types of lymphoma. For example, IL-4 is responsible for the T-cell reaction in T-cell-rich B-cell lymphoma, while IL-6 is accountable for the plasma cell reaction in angioimmunoblastic lymphadenopathy-type T-cell lymphoma. Others may be directly involved in the tumor cell growth or differentiation. For instance, IL-9 may be important for the autocrine proliferation of anaplastic large cell lymphoma, whereas IL-6 is essential for plasmacytoid differentiation in polymorphic immunocytoma. Further studies of the roles of cytokines in lymphomas may lead to major advances in the understanding of the molecular processes involved in the histopathogenesis of malignant lymphomas. Elucidation of the autocrine or paracrine function of cytokines also may lead to new approaches to a rational intervention in these disease processes.

Castleman Disease↗

Pathogenic significance of interleukin-6 in angioimmunoblastic lymphadenopathy-type T-cell lymphoma.

Patients with angioimmunoblastic lymphadenopathy (AILD)-type T-cell lymphoma may develop hypergammaglobulinemia. Among four cases of AILD-type T-cell lymphoma that we have studied, we detected a correlation between the number of plasma cells in tissue and the extent of interleukin-6 (IL-6) expression in lymphoma cells. We did not detect IL-6 in three patients who had no hypergammaglobulinemia and whose tissues showed only minimal plasma cell infiltration. In the fourth patient we observed an abundant IL-6 production by lymphoma cells, which accounted for a B-cell plasmacytic tissue response and for hypergammaglobulinemia. The pathogenic significance of IL-6 was substantiated by a concomitant decrease in the serum IL-6 level, measurable tumor mass, and immunoglobulin levels, as well as by a decline in the proportion of plasmacytoid cells in peripheral blood promptly on administration of chemotherapy. Plasmacytoid B cells could be maintained in culture in the presence of IL-6, but viability was lost on co-incubation with anti-IL-6. Interleukin-1 and tumor necrosis factor were not produced by T lymphoma cells and were incapable of sustaining plasmacytoid B-cell viability in vitro. Small amounts of IL-4 were noted in T lymphoma cells. Thus, in this case of AILD-type T-cell lymphoma, tumor cells with a T-cell phenotype produced IL-6 in large quantities, explaining the accompanying B-cell and plasmacytic histologic changes and humoral disease manifestations, including marked hypergammaglobulinemia. Although not all cases of AILD-type T-cell lymphoma have an accompanying plasma cell proliferation and hypergammaglobulinemia, and although the cytokine network in these patients may be more complex than has been recognized, this case with IL-6 expression serves to illustrate the utility of cytokine assays in the analysis of the histopathologic and clinical heterogeneities of peripheral T-cell lymphomas.

Aged↗

[A preliminary report about body shape and composition of 300 citizens in Kaohsiung City].

We studied 300 healthy citizen of Kaohsiung City, Taiwan, to discover factors that affect body shape, and especially body weight. It's our hope that we could find an objective evaluative index to assess obesity that would be suitable for use in out-patient clinics. During the study period, 300 healthy, under 50 years old volunteers were participated in our study. All the participant were asked to completed a questionnaire and anthropometric measures for analysis. The result of our study showed that age, sex and drinking habit all were significantly affected body shape. We also found that relative body weight and subscapular skinfold thickness are best predictor of body fat composition. Therefore, we suggest the combined use relative body weight and subscapular skinfold thickness as an index for assessing obesity in out-patient clinics.

Adult↗

[Hematometra in patients with cervical cancer--its CT presentation and clinical significance].

Cervical cancer is the most common gynecologic malignancy in Chinese. Clinical staging has been traditionally used in cervical cancer, according to international Federation of Gynecology and Obstetrics (FIGO) staging classification. Computed tomography was an adjunctive modality for detecting paraaortic lymph nodes in preoperative evaluation. But CT has failed to accurately define the extent of parametrial and vaginal invasion. Here, an attempt has been made to define indirect clues alerting to invasive cervical cancer. Hematometra can be seen in CT as a dilated uterine cavity with retention of significant fluid. The incidence of hematometra was 5% (5/101) in control group, and 26% (22/84) in cervical cancer. Hematometra cannot be more specific for cervical cancer, with an accuracy of 64%, sensitivity of 82% and specificity of 61%. Hematometra was found to have a statistically high relationship with high cancer staging and uterine invasion. The Chi-square values were 14.8 (P < 0.005) in high cancer staging, and 19.8 in uterine invasion. The accuracy of hematometra was 65% in high cancer staging, and 74% in uterine invasion. Hematometra was more common in postmenopause women, with accuracy elevated to 80% for uterine invasion. This is probably related to senile atrophy or endophytic growth of the cervix into the uterus as well as to hormone replacement. These were five false positive instances of hematometra, all unrelated to cervical cancer. They presented with marked fluid and a solid mass in the uterine cavity, and included endometrial adenocarcinoma, uterine myoma and leiomyosarcoma. None of cervical cancer showed a solid mass in a dilated uterine cavity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Russell bodies consist of heterogenous glycoproteins in B-cell lymphoma cells.

The phenotypic expression of Russell bodies (RB) in the tumor cells of two patients with different types of B-cell lymphoma and of one patient with plasma cell myeloma were examined. In both B-cell lymphomas, the RBs reacted consistently with anti-Leu 8 and anti-immunoglobulin M. The RBs in one case also reacted with other monoclonal antibodies, including anti-CD5, CD19, CD22, and CD25. The membranes of most of the tumor cells containing RBs did not stain. In the myeloma, the RBs reacted only with anti-immunoglobulin, and the myeloma cells expressed no surface antigens associated with B lymphocytes. This finding suggests that RBs do not form in cells that can transport glycoproteins to the cell membrane, but rather occur as a result of defective transport or process of certain glycoproteins by plasmacytoid cells.

Antibodies, Monoclonal↗

Thrombomodulin expression in malignant pleural mesothelioma and pulmonary adenocarcinoma.

Thrombomodulin (TM) is a glycoprotein of molecular weight 75,000 kd that is normally present in restricted numbers of cells, including endothelial and mesothelial cells. In this study, the authors tested the possibility of using anti-TM to facilitate the diagnosis of mesothelioma. All of the 31 mesotheliomas and the two mesothelioma cell lines (MS-1 and MS-2) tested were stained positively with anti-TM. The specificity of anti-TM staining in mesothelioma cells was further confirmed by in situ hybridization of MS-1 cells with a TM-specific probe. The expression of TM in MS-1 cells was increased markedly when these cells were induced by 12-0-tetradecanyl phorbol 13-acetate (TPA) to differentiate. The expression of TM in mesothelioma cells, however, did not correlate with any particular phase of the cell cycle. In an attempt to differentiate pleural mesothelioma from pulmonary adenocarcinoma, the authors compared the expression of TM, carcinoembryonic antigen (CEA), and Leu M1 in these two types of tumors. Only four of 48 (8%) pulmonary adenocarcinomas were stained positively by antibodies to TM. Therefore, immunohistochemical staining with antibodies to TM yielded 100% sensitivity and 92% specificity for diagnosis of mesothelioma. All of the mesotheliomas stained negatively for CEA and Leu M1, except for one, which showed minimal focal positivity for Leu M1. In contrast, 79% and 60% of adenocarcinomas stained positively for CEA and Leu M1, respectively. These findings suggest that immunocytochemical staining with anti-TM should be added to the battery of tests to increase the diagnostic sensitivity and specificity for differentiating mesothelioma from pulmonary adenocarcinoma.

Adenocarcinoma↗

Functional heterogeneity and pathogenic significance of interleukin-6 in B-cell lymphomas.

A possible autocrine effect of interleukin-6 (IL-6) on the growth and differentiation of the tumor cells of 55 B-cell lymphomas was examined. Interleukin-6 was detected in a few types of B-cell lymphomas, including polymorphic immunocytoma (PI), small lymphocytic lymphoma (SLL), and immunoblastic lymphoma (IBL) with or without plasmacytoid differentiation. In PI and in IBL with plasmacytoid differentiation (IBL-P), IL-6 was detected only in immunoglobulin-containing plasmacytoid cells, and it was absent from most proliferating (Ki-67/PCNA-positive) lymphoma cells. In SLL, IL-6 was not observed in lymphoplasmacytoid cells; instead, IL-6 was observed in transformed (Ki-67/PCNA-positive) tumor cells in proliferation centers. The lymphoplasmacytoid cells in SLL exhibited a phenotype (IL-6/glutathione-S-transferase-pi [GST-pi]-negative), different from that of normal plasma cells (IL-6-negative/GST-pi-positive) and from the plasmacytoid cells (IL-6/GST-pi-positive) in PI and IBL-P. In IBL without obvious plasmacytoid differentiation, IL-6 was detected in most tumor cells that were highly proliferative (Ki-67/PCNA-positive). In this study, IL-6 was undetectable in most lymphomas related to follicular centers, in lymphoblastic lymphoma, in small noncleaved cell lymphomas of the Burkitt and non-Burkitt types, and in diffuse large cell lymphoma. This finding is compatible with a previous finding that IL-6 mRNA was absent from follicular center cells in reactive lymphoid tissues. The functions of IL-6 in these lymphomas may be quite diverse. It appears that IL-6, as an autocrine factor, is responsible for the plasmacytoid differentiation of lymphoma cells in IP and some IBL (IBL-P). The differentiation of lymphoplasmacytoid lymphoma cells in SLL, however, may not be mediated by an autocrine IL-6 mechanism. Interleukin-6 may provide a growth signal, rather than acting as a differentiation factor, for some IBL cells and for some transformed tumor cells in proliferation centers in SLL.

Cell Differentiation↗

Interleukin-4 may contribute to the abundant T-cell reaction and paucity of neoplastic B cells in T-cell-rich B-cell lymphomas.

T-cell-rich B-cell lymphomas (TCRBCLs) are diffuse lymphomas that contain a minority of large neoplastic B cells amidst a majority of non-neoplastic T cells and numerous histiocytes, an unusually pronounced reactive component not seen in most diffuse large B-cell lymphomas (DLBCLs). This reaction may be influenced by various cytokines secreted by lymphoma or reactive cells; therefore, expression of interleukin (IL)-1 beta, IL-2, IL-4, IL-6, and IL-9 was evaluated immunohistochemically on paraffin-embedded sections of 18 TCRBCLs and was compared with that of 15 DLBCLs containing a minority of reactive T cells and to that of seven reactive lymph nodes. Moderate to intense expression of IL-4 was detected in variable numbers of tumor cells and in numerous histiocytes in 16 TCRBCLs. In contrast, intense IL-4 expression in numerous histiocytes was observed in only one of 15 DLBCLs with few T cells. In four other DLBCLs and three reactive nodes, moderate to intense staining for IL-4 was noted only in rare large transformed cells or in occasional histiocytes. Except for one IL-1 beta positive and another IL-9 positive TCRBCL, there was no marking or weak staining only with other cytokine antibodies in the neoplastic and reactive cases studied. The expression of IL-4 in most TCRBCLs, but not in other DLBCLs or in reactive nodes, suggests that this cytokine is one factor involved in the pathobiology of the abundant T-cell reaction and, perhaps, contributes to the paucity of neoplastic B cells in TCRBCLs.

B-Lymphocytes↗

Interleukin-6, but not interleukin-4, is expressed by Reed-Sternberg cells in Hodgkin's disease with or without histologic features of Castleman's disease.

Hodgkin's disease (HD) is a neoplastic disease that is characterized by unbalanced and/or unregulated cytokine production. Information accumulated in our own and other laboratories indicates that the cytokines interleukin-1 (IL-1), IL-5, IL-9, tumor necrosis factor-alpha (TNF-alpha), granulocyte colony-stimulating factor (G-CSF), macrophage CSF (M-CSF), and transforming growth factor-beta (TGF-beta) are secreted by Hodgkin's and Reed-Sternberg (H-RS) cells. These and perhaps additional cytokines are likely to be responsible for the unique histopathologic and clinical alterations seen in patients with HD. In this study, we confirmed that IL-6 is produced by cultured H-RS cells as well as by H-RS cells in tissues. By using an enzyme-linked immunosorbent assay, we found that approximately 2 to 10 ng/ml of IL-6 was secreted by cultured H-RS cells (10(6) cells/ml). In tissues, we were able to immunolocalize IL-6 in the cytoplasm in 10 to 30% of H-RS cells by using rabbit polyclonal and mouse monoclonal anti-IL-6 antibodies. There was no correlation among the IL-6 staining intensity, number of H-RS cells stained, and the degree of plasma cell infiltration. However, in 3 of 17 cases studied, a large number (60%) of H-RS cells were positive for IL-6, and in these patients, abundant plasma cells were present. In one patient, the involved lymph node also showed histologic features similar to those of Castleman's disease. In this patient, we noted abundant IL-6 expression not only in H-RS cells, but also in most reactive histiocytes. The cultured H-RS cells did not express functional receptors for IL-6, and exogenously added IL-6 did not induce proliferation of these cells. We also conducted studies with specific anti-IL-4 antibodies, which did not show IL-4 production by H-RS cells in both cultures and tissues. In tissues, only rare IL-4 positive lymphoid cells or dendritic cells were identified. Thus, the study demonstrated that adequate amounts of IL-6 are required for an abundant plasma cell reaction, and that an additional source of IL-6 from histiocytes is essential for the formation of Castleman's disease-like changes in lymph nodes involved by HD. Furthermore, IL-4 is not likely to be responsible for the T-lymphocyte reaction in tissues, by a mechanism distinct from that in T-cell-rich B-cell lymphomas.

Aged↗