Epstein-Barr virus-positive Hodgkin/Reed-Sternberg-like B cell in non-hodgkin lymphoma: nucleotide sequence of the amplified immunoglobulin heavy-chain variable region gene by the single-cell polymerase chain reaction technique.

We examined nucleotide sequences of Epstein-Barr virus (EBV)-positive Hodgkin/Reed-Sternberg (HRS)-like B cells in a case of diffuse large B-cell lymphoma (DLBCL) and a case of adult T-cell lymphoma (ATL) for single-cell polymerase chain reaction of the immunoglobulin heavy-chain gene variable region (VH gene). HRS-like B cells were scattered in the area irrelevant to the lymphoma infiltrates of DLBCL and in the lymphoma area of ATL. HRS-like B cells were positive for CD20 and CD30 but negative for CD15. EBV presented in HRS-like B cells in both cases but not in any lymphoma cells. VH genes of five HRS-like B cells analyzed in DLBCL were polyclonal and showed in-frame sequences with 0% to 2.8% somatic mutation frequency. In an ATL, VH genes of five HRS-like B cells analyzed were polyclonal and somatically mutated. Four cells carried in-frame rearrangements with 3.5% to 17.7% mutation frequency. One of the VH genes has a one-codon deletion. From the fifth cell, an out-of-frame rearrangement with an insertion and a deletion was obtained. Thus, we showed polyclonal EBV-positive HRS-like B cells in both DLBCL and ATL and that whereas EBV-positive, HRS-like B cells in DLBCL exhibited unmutated and mutated VH gene, those in ATL were found to have a somatically mutated VH gene with/without deletions and/or insertions. The HRS-like B cells may appear because of active EBV infection in a patient who is immunosuppressed from the primary lymphoma.     

Transgenic mice with an expanded CAG repeat controlled by the human AR promoter show polyglutamine nuclear inclusions and neuronal dysfunction without neuronal cell death

We generated transgenic mice that expressed a highly expanded 239 polyglutamine (polyQ) repeat under the control of the human androgen receptor promoter. These transgenic mice developed progressive neurological phenotypes of muscular weakness and ataxia, small body size and short life-span. PolyQ nuclear inclusions (NIs) were remarkable and widespread but found in selective regions of the central nervous system (CNS) such as the spinal cord, cerebrum and cerebellum as well as in selective peripheral visceral organs. This distribution pattern resembled that of spinal and bulbar muscular atrophy somewhat, but was more widespread. In neuronal tissues, NIs were present in astrocytes as well as neurons. Cytoplasmic and axonal inclusions were not observed. In the CNS regions with abundant NIs, neuronal populations were well-preserved, and neither neuronal cell death, reactive astrogliosis nor microglial invasions were detected. These findings suggest that polyQ alone can induce the neuronal dysfunction that precedes gross neuronal degeneration and provides a clue for investigating molecular mechanisms that underly the pathway to neuronal dysfunction from polyQ expansion.     

Expression of BAFF-R (BR3) in normal and neoplastic lymphoid tissues characterized with a newly developed monoclonal antibody

BAFF-receptor (BAFF-R) is required for the successful maturation and survival of B-cells. We developed an anti-human BAFF-R monoclonal antibody (mAb), 8A7. The reactivity of 8A7 in normal and neoplastic tissue was examined by performing immunohistochemistry on paraffin-embedded sections. 8A7 reacted with lymphocytes in the mantle and marginal zones, but not with lymphocytes in the interfollicular area. Lymphocytes in the germinal centers were found to be negative or occasionally weakly positive for 8A7. BAFF-R expression was found only in B-cell lymphoma (44/80, positive cases/examined cases): B-lymphoblastic lymphoma 0/3, B-chronic lymphocytic leukemia/small lymphocytic lymphoma 4/4, mantle cell lymphoma 9/11, follicular lymphoma 10/14, diffuse large B-cell lymphoma (DLBCL) 11/25, marginal zone B-cell lymphoma 8/10, lymphoplasmacytic lymphoma 2/2, plasma cell myeloma 0/2, and Burkitt lymphoma 0/9, but not in T/NK cell lymphomas (0/19) or Hodgkin lymphoma (0/10). BAFF-R was expressed in most low-grade B-cell neoplasms and a small number of DLBCL, suggesting that BAFF-R may play an important role in the proliferation of neoplastic lymphoid cells. Thus, the mAb is very useful for further understanding of both healthy B-cell biology and its pathogenic neoplasms.     

Unique three-way translocation, t(3;14;18)(q27;q32;q21), in follicular lymphoma

A 43-year-old woman was diagnosed as having stage IV follicular lymphoma. Phenotypically, the lymphoma cells were CD5(-), CD10(+), CD19(+), CD20(+), CD23(-), HLA-DR(+), and IgM-lambda(+). Conventional chromosomal analysis showed a three-way t(3;14;18)(q27;q32;q21) in the lymphoma cells, which was confirmed by spectral karyotyping (SKY) and fluorescence in situ hybridization (FISH). Immunohistochemistry revealed that both BCL2 and BCL6 proteins were expressed in the lymphoma cells, whereas only the BCL6 gene, and not the BCL2 gene, was rearranged by Southern blotting. The patient received combination chemotherapy and has been well for 3 years. This is the first reported case showing a three-way translocation involving 2 major lymphoma-specific abnormalities, 3q27 and t(14;18)(q32;q21).     

A consistent region of deletion on 1p36 in meningiomas: identification and relation to malignant progression

We analyzed the genetic aberrations on chromosome arms 1p, 10q, and 14q, which are thought to be loci that include putative tumor suppressor genes in meningiomas. We initially conducted molecular genetic testing on a total of 72 tumors including 15 atypical and 8 anaplastic meningiomas using double-target fluorescence in situ hybridization. An incidence of deletion of 1p was observed in 16.3% of histologically benign, 86.7% of atypical, and 87.5% of anaplastic meningiomas. Microsatellite analysis for loss of heterozygosity on 1p, 10q, and 14q was performed in 15 tumors (6 benign, 6 atypical, and 3 anaplastic meningiomas). We detected a limited deleted region on 1p36 in two tumors and suggest a new consistent region of deletion at 1p36.21p23 distal to D1S507 and proximal to D1S214, which spans 8.21 megabases. In addition, loss of 10q was detected in two of three secondary atypical meningiomas, and loss of 14q in two of three primary anaplastic meningiomas. We suggest that one of the putative suppressor genes is located at 1p36.21p23, and that 10q loss may contribute to the malignant progression from benign to atypical meningiomas.     

Oxygen radical production by neutrophils from patients with bacterial infection and rheumatoid arthritis

The production of three kinds of oxygen radicals (superoxide, hydrogen peroxide, and hydroxyl radicals) by neutrophils from patients with bacterial infection or rheumatoid arthritis was measured. The stimulators used in this study were opsonized zymosan (1 mg/ml), phorbol myristate acetate (20 ng/ml), A23187 (1M, and platelet activating factor (1M). Oxygen radical production by neutrophils from patients with rheumatoid arthritis was not significantly different from that of the control group. Hydrogen peroxide production by the neutrophils from patients with bacterial infection was significantly enhanced by only opsonized zymosan, but the production of the other kinds of oxygen radicals was not. Cytochalasin B reduced the production of hydrogen peroxide induced by opsonized zymosan more markedly than that of any other kind of oxygen radical. The measurement of hydrogen peroxide is suggested to be the most accurate indicator of the enhancement of intracellular production of oxygen radicals by neutrophils during infection.     

Thymic sarcomatoid carcinoma with skeletal muscle differentiation: report of two cases, one with cytogenetic analysis

AIMS: Malignant thymic tumour histologically resembling a soft tissue sarcoma is extremely rare and defined as sarcomatoid carcinoma in the recent World Health Organization (WHO) classification. We report two such cases in which the tumour cells showed a prominent rhabdomyoblastic differentiation and analyse whether these tumours retain an epithelial nature at least in part. METHODS AND RESULTS: One tumour occurred in a 51-year-old man (Case 1) and the other in a 40-year-old woman (Case 2). Microscopically, both tumours consisted essentially of two types of tumour cells: spindle and large round cells, with no apparent epithelial components. Osteosarcomatous small foci were also found in Case 2. Immunohistochemically, desmin and muscle-specific actin were positive in the majority of both types of tumour cells, whereas myogenin was predominant in the spindle cells and myoglobin in the large round cells. Some of both types of cells expressed cytokeratin with co-expression of myoglobin in the large round cells, but with no myogenin in the spindle cells. Some cytokeratin-positive spindle cells were also negative for desmin. Ultrastructural examination of a recurrent tumour in Case 2 revealed some epithelial features among the spindle cells. Cytogenetic study of the same tumour showed a complex abnormality including der(16)t(1;16)(q12;q12.1), an identical pattern previously reported in a case of thymic squamous cell carcinoma. CONCLUSIONS: The findings support the definition in the WHO classification of sarcomatoid carcinoma that includes purely sarcomatous tumour as in the present cases. Occurrence of this type of tumour may indicate a relationship between thymic epithelial cells and myoid cells and/or a potential for divergent differentiation in thymic epithelial tumours.     

Telomerase activity in the human endometrium throughout the menstrual cycle

In a total of 41 endometrial tissue samples, the relationship between telomerase activity and proliferating cell nuclear antigen (PCNA) labelling index was studied. In samples of endometrium from the proliferative phase of the menstrual cycle, telomerase activity was found in 15 out of 17 cases (88%). Two samples from the early proliferative phase showed negative telomerase activity and a low PCNA labelling index. However, three out of 16 samples of early secretory phase endometrium showed telomerase activity and a PCNA labelling index. In mid- to late secretory phase endometrium, in menopausal endometrium and in decidualized endometrium induced by progesterone neither telomerase activity nor PCNA labelling was found. These results suggest that telomerase activity of the endometrium may be correlated with the proliferative potential of the epithelial cells and that its activity may be regulated by oestrogen.      

Sequential change of the hypervariable region of the hepatitis C virus genome in acute infection

Hepatitis C virus (HCV) infection is characterized by persistence of liver inflammation that often leads to end-stage liver disease, although the mechanisms are not fully understood. A hyper-variable region (HVR) has been reported in the E2/NS1 region of the HCV genome, in which striking diversity is found among different HCV isolates. To investigate the association of the HVR alterations with the clinical courses of HCV infection, a longitudinal analysis of the HVR in patients with acute HCV infection was carried out. Plasma samples were obtained at several times in three patients with acute hepatitis C. Plasma RNA was extracted and reverse transcribed, and DNA fragments that included the HVR were amplified by PCR. The sequences of the HVR were directly determined from the PCR products by the dideoxy chain termination method, from which amino acid sequences were deduced. In all cases, plasma HCV-RNA disappeared with the improvement of the initial alanine aminotransferase (ALT) elevation, but HCV-RNA reappeared about 1 year later with or without deterioration of the hepatitis. In a case of sporadic acute hepatitis, the HCV in the recurrent phase had seven amino acid substitutions in the HVR compared with that in the acute phase, although no amino acid changes were noted during the initial acute phase. In a case of posttransfusion hepatitis, a marked difference was observed between the acute and the recurrent phases, with an amino acid homology of 30% (8/27). The mutation rate of the HVR had a tendency to accelerate as the HCV infection progressed to the chronic stage. In conclusion, the HVR changes serially during the course of acute HCV infection, and these HVR changes may play a part in the chronicity of HCV infection. © 1994 Wiiey-Liss, Inc.