Study of Vimentin Expression in Non-Hodgkin's Lymphoma Using Paraffin Sections

Human non-Hodgkin's lymphomas were studied by means of an avidin biotin complex immunoperoxidase method using several monoclonal antibodies against the intermediate filament protein, vimentin. The study cases were 61 B cell lymphomas (including 2 plasmacytomas) and 30 T cell lymphomas (including 8 cases of mycosis fungoides). Twelve of the 61 B cell lymphomas were positive for vimentin, and were composed of extrafollicular center cells such as immunoblastic and plasmacytoid cells. On the other hand, lymphomas of follicular center cell origin were negative for vimentin. All cases of T cell lymphoma except for 14 (all of 9 AlLD- type lymphomas, all of 4 lymphoblastic lymphomas and one diffuse mixed small/ large lymphoma) were positive for vimentin. Although vimentin expression appeared to be influenced by various conditions such as the proportion of T- and B cell subsets, or B cell proliferation rate, follicular center cells were constantly negative for vimentin.     

Malignant Fibrous Histiocytoma with Epithelial Differentiation?

A case of recurrent soft part sarcoma with focal areas showing epithelial differentiation in the right thigh in a 78-year-old woman is reported. The primary tumor consisted of myxoid areas and solid areas, in which relatively uniform epithelioid tumor cells were arranged in sheets, whereas pleomor-phism and a storiform pattern appeared in the recurrent tumors. Thus this tumor was suspected to be a malignant fibrous histiocytoma. However, further studies showed unexpected ultrastructural and immunohistochemical features. Cytokeratin immu-noreactivity and tonofilamentlike structures probably indicated epithelial differentiation of some tumor cells. From the clinical and histological findings, this tumor should be identified as a malignant fibrous histiocytoma with phenotypic expressions of epithelial cell.     

Effect of high NaCl intake on Na+ and K+ transport in the rabbit distal convoluted tubule

Morphological studies have demonstrated that a chronic increase in distal Na⁺ delivery causes hypertrophy of the distal convoluted tubule (DCT). To examine whether high NaCl-intake also causes functional changes in the well defined DCT, we measured transmural voltage (V _T), lumen-to-bath Na⁺ flux (J _Na(LB)), and net K⁺ secretion (J _K(net)) in DCTs obtained from control rabbits and those on high NaCl-intake diets. The lumen negativeV _T was significantly greater in the high NaCl group than in the control group. The net K⁺ secretion (pmol mm^–1 min^–1) was greater in the high NaCl-intake group (54.1±13.0 vs 14.7±5.6). The K⁺ permeabïlities in both luminal and basolateral DCT membranes, as assessed by the K⁺-induced transepithelial voltage deflection inhibitable with Ba²⁺, were increased in the experimental group. The lumen-to-bath²²Na flux (pmol mm^–1 min^–1) was also greater in the experimental group (726±119 vs 396±65). TheV _T component inhibitable with amiloride was also elevated in the high NaCl-intake group. Furthermore, Na⁺–K⁺-ATPase activity of the DCT was higher in the experimental than in the control group. We conclude that high NaCl intake increases both Na⁺ reabsorption and K⁺ secretion by the DCT. This phenomenon is associated with an increased Na⁺–K⁺-ATPase activity along with increased Na⁺ and K⁺ permeabilities of the luminal membrane, and an increase in the K⁺ permeability of the basolateral membrane. Cellular mechanisms underlying these functional changes remain to be established.     

Spatiotemporal changes of coxsackievirus and adenovirus receptor in rat hearts during postnatal development and in cultured cardiomyocytes of neonatal rat

Coxsackievirus B is the most common cause of viral myocarditis and is particularly virulent in neonates and children. Adenovirus is also a leading cause of the disease. The determinant of tropism for both viruses is considered to be the expression of coxsackievirus and adenovirus receptor (CAR) in target organs. However, developmental change and physiological localization of CAR in the heart are unknown. We examined expression levels of CAR in rat hearts by quantitative real-time polymerase chain reaction and Western blot analysis and found that CAR decreased gradually during postnatal development, although CAR was detectable, even in adults. Immunohistochemistry revealed CAR on the whole surface of cardiomyocytes in immature rat hearts. In contrast, CAR was detected predominantly on intercalated disks in the adult heart and was accumulated especially at the contact point between the cultured cardiomyocytes, even though they were prepared from the neonatal rat heart. In conclusion, CAR was expressed abundantly on the whole surface of cardiomyocytes in immature rat hearts. Both the expression level and the localization of CAR are possible determinants of the susceptibility to viral myocarditis of neonates and children.     

Effects of repeated subculturing and prolonged storage at room temperature of enterohemorrhagic Escherichia coli O157:H7 on pulsed-field gel electrophoresis profiles

Three clinical strains of enterohemorrhagic Escherichia coli O157:H7 which were subcultured repeatedly or stored at room temperature over a 25-week period showed appreciable variations in their pulsed-field gel electrophoresis fragment patterns. The variations could be explained by a couple of spontaneous genetic events at most and thus did not invalidate the genetic lineage of the strains.     

Expression of CD80 and CD86 on Peripheral Blood T Lymphocytes in Patients with Systemic Lupus Erythematosus

CD80 and CD86 were detected in high amounts on circulating T cells in the peripheral blood of some patients with systemic lupus erythematosus (SLE), using flow cytometry and monoclonal antibodies. Patients with other connective tissue diseases did not have a high percentage of T cells expressing CD80 or CD86 in their peripheral blood. CD80 was expressed mainly on CD4 T cells, whereas CD86 was expressed on CD8 T cells, and these two populations were associated with paticular clinical features. These two molecules were expressed on different T-cell populations and might have different roles in the generation and regulation of immune responses. Since high expression of CD86 on T cells was detected much earlier than the appearance of clinical features and a high titer of anti-DNA antibody, it may be a useful parameter for predicting the flare of SLE.     

An autopsy case of acquired immune deficiency syndrome (AIDS) with preceding aplastic anemia

A case of acquired immunodeficiency syndrome (AIDS) with preceding aplastic anemia is reported. The patient was a 36 year old female who had been diagnosed as having aplastic anemia 10 years before and thereafter had received multiple transfusions. Human immunodeficiency virus (HIV)-seropositivity was revealed 10 months prior to her death, but no particular clinical signs indicating HIV infection, pre-AIDS or onset of AIDS were recognized before serological diagnosis, although the slow progression of leukopenia was noted along with thrombocytopenia. Her general condition deteriorated during the last 10 months accompanied by an acute decrease In the CD4/CD8 ratio. Autopsy revealed full-blown AIDS: systemic aspergillosis, progressive multifocal leukoencephalopathy, Epstein-Barr virus-related B cell lymphoma arising in the diaphragm and severe lymphocyte depletion in the lymph nodes and spleen. Markedly hypo-plastic bone marrow was considered to be primarily attributable to the aplastic anemia but the affection of AIDS was not excluded. The possible transmission route of HIV and the effect of the preceding aplastic anemia on the infection and clinical course of AIDS are discussed.     

Long-term inhibition of intimal hyperplasia using vascular photodynamic therapy in balloon-injured carotid arteries

Flexible treatments for intimal hyperplasia after angioplasty are still needed. The aim of this study was to demonstrate the long-term effects of vascular photodynamic therapy with talaporfin sodium on intimal hyperplasia following interventional injury. Intimal hyperplasia was induced by balloon distension injury to the carotid artery in 31 rabbits. Talaporfin, 5.0 mg/kg, was delivered systemically immediately after balloon injury. The injury site was irradiated with a diode laser light of wavelength 664 nm using a fluence of 50 J/cm² after 30 min. At day 3 and weeks 3, 6, 9, 15, and 25 after photodynamic therapy, the treated artery of each rabbit was excised and examined immunohistochemically. Thirty minutes after talaporfin administration, drug fluorescence was found only in the balloon-injured carotid artery wall. At 3 days, no smooth muscle cells were seen in the media of the photodynamic therapy-treated arterial segments. Intimal hyperplasia developed progressively in the balloon-injured and untreated segments; however, in the segments treated with photodynamic therapy, intimal hyperplasia was markedly suppressed until 25 weeks and the media was repopulated by smooth muscle cells without macrophages. Vascular photodynamic therapy with talaporfin may be used to inhibit restenosis after vascular intervention. An erratum to this article is available at .     

Light-dark patterns in running-wheel activity in rats during chronic administration of theophylline

Running-wheel activity for 24 hr and activity patterns were studied during chronic theophylline administration. Theophylline altered the normal relations between activity level and illumination. Dark-time activity was decreased to approximately 50% and 24 hr activity was unaffected. These observations were consistent with previous results showing that theophylline suppressed dark-time feeding but had no effect on 24 hr food intake. A possible mechanism to account for these results may be dependent on levels and turnover of brain norepinephrine.