Contrasting effects of hydroxyurea on cell growth and reduction in Epstein-Barr virus genomes in EBV-infected epithelioid cell lines vs Burkitt's lymphoma cell lines

Eliminating Epstein-Barr virus (EBV) genomes from infected cells is an intriguing theoretical strategy in therapy for EBV-associated malignant diseases. Respective patterns were characterized for hydroxyurea (HU)-promoted loss of EBV genomes from EBV-infected epithelioid cell lines derived from the noncancerous portion of gastric carcinoma tissues and Burkitt's lymphoma (BL) cell lines. Epithelioid cell lines GT38 and PN were less sensitivity to HU than BL cell lines Akata, Raji, and Daudi in terms of cell growth inhibition and cell cycle arrest. On passage in medium with 50 microM HU, the fraction of EBV nuclear antigen (EBNA)-positive cells was reduced substantially in the BL cell lines, but only slightly in the epithelioid cell lines. EBV DNA was reduced in Akata, Raji, and Daudi cells upon passage in 50 microM HU by 95%, 70%, and 50%, respectively, but by only 10% in GT38 cells, in which EBV DNA reduction was enhanced at increased concentrations of HU. This indicates that EBV genome is more easily lost from BL cell lines than from epithelioid cell lines upon culturing in HU. These findings support the view that the elimination of EBV could be therapeutically effective in EBV-associated BL by HU.     

Role of apoptosis controlled by cytochrome c released from mitochondria for luteal function in human granulosa cells

PROBLEM: The aim of this study was to investigate the relationship between apoptosis by the mitochondrial pathway and luteal function in human granulosa cells. METHOD OF STUDY: Granulosa cells were obtained by ultrasound-guided follicular aspiration from patients undergoing in vitro fertilization and embryo transfer. After the addition of RU486, cells were stained with a mitochondria-specific fluorescent dye, MitoTracker Red CM x Ros. Using flow cytometry and National Institute of Health image, the mitochondrial fluorescent area was measured. After staining with Hoechst 33258 dye, the number of apoptotic bodies per 1000 cells were counted at random on photomicrographs. Homogenates were used for sodium dodecyl sulphate-polyacrylamide gel electrophoresis and Western blot analysis using antibodies against cytochrome c or caspase-3. RESULTS: The incidence of apoptotic bodies increased and the mitochondrial membrane potential decreased time dependently. The opposite effect was observed dose dependently with RU486 treatment. Western blot analysis showed increased cytochrome c expression, after treatment with 1-2 microg/mL of RU486 which then decreased with 5-10 microg/mL of RU486. Caspase-3 expression increased dose dependently with RU486. CONCLUSIONS: These results suggest that the activation of caspase-3 caused by cytochrome c released from mitochondria plays an important role in apoptosis-related luteal function in human granulosa cells.     

Experimental study on secondary amyloidosis associated with chronic arthritis

Various organs from rabbits immunized with heat-killed E. coli 0:14 to induce chronic polyarthritis resembling rheumatoid arthritis (RA) were examined for amyloid deposition since amyloidosis is a frequent feature of long-standing RA. Amyloids were confirmed mainly by polarizing as well as nonpolarizing light microscopy after Congo red staining and partly by electron microscopy and immunoperoxidase technique. Amyloid deposits after an additional 2 months from the first appearance of arthritis were most frequently found in the spleen and kidneys suggesting secondary amyloidosis. Amyloidosis was observed in 36% of 75 arthritic rabbits. The incidence of amyloidosis was significantly higher in the arthritic rabbits than in the non-arthritic rabbits (p less than 0.05). This suggests that prolonged sensitization with heat-killed E. coli 0:14 containing endotoxic substance participates in the formation of both arthritis and amyloidosis.     

Differential susceptibility of resting CD4(+) T lymphocytes to a T-tropic and a macrophage (M)-tropic human immunodeficiency virus type 1 is associated with their surface expression of CD38 molecules

Recent evidence has accumulated which definitively shows that chemokine receptors CCR5 and CXCR4 play an essential role as coreceptors for human immunodeficiency virus type 1 (HIV-1) infection. Flow cytometric analysis permitted us to detect CD38, a surface marker of early differentiation, as well as activation of T cells, on about half of healthy donor-derived CD4(+) T cells. In this study, we focused on the susceptibility of CD38(+) and CD38(-) subsets of CD4(+) T cells to HIV-1 infection with different coreceptor tropisms. About 20% of peripheral blood mononuclear cell-derived resting CD4(+) T cells were recovered into the CD38(+) subset fraction by panning with a monoclonal antibody to CD38. Most of the cells in this CD38(high) fraction also expressed CD45RA and CD62L at higher intensities compared with those of CD38(low) fraction. CCR5(+) T cells predominated in the CD38(-) subset, although cell surface expression of CD4 and CXCR4 was almost similar between both subsets. This difference was consistent with a significantly higher susceptibility of the CD38(-) subset to a macrophage (M)-tropic HIV-1 strain. In contrast, it was shown that a T-tropic strain of HIV-1 could replicate more efficiently in the CD38(+) subset, although viral adsorption rates were similar between both subsets. Thus, the differential susceptibility of CD4(+) T cells to M(-) and T-tropic HIV-1 was associated with their surface expression of CD38.     

Resting CD4(+) T cells with CD38(+)CD62L(+) produce interleukin-4 which contributes to enhanced replication of T-tropic human immunodeficiency virus type 1

A significant increase in the CD38(+) population among T lymphocytes has been observed in human immunodeficiency virus type 1 (HIV-1)-infected carriers. We previously reported a higher replication rate of T-tropic HIV-1 in the CD4(+)CD38(+)CD62L(+) than CD38(-) subset under conditions of mitogen stimulation after infection. Here, we revealed a similarly high susceptibility in the CD38(+) subset on culture with conditioned medium containing Th2 cytokine, interleukin (IL)-4 that was produced endogenously from this subset on stimulation with mitogen or anti-CD3 antibody for 3 days. The contribution of IL-4 to the upregulated production of virus in the CD38(+) subset was confirmed by culture of this subset with recombinant human IL-4. In contrast, the rate of replication in the CD38(-) subset was not augmented in the conditioned medium from either subset or with IL-4. However, there were no differences in the surface expression of IL-4 receptor or HIV-1 receptors CD4 and CXCR4 between the two subsets. Thus, the CD4(+)CD38(+)CD62L(+) subset comprises a specific cell population secreting endogenous Th2 cytokine that contributes to the efficient production of T-tropic HIV-1 through upregulation at a certain stage of the viral life cycle, probably after the adsorption step.     

ADRENAL PHEOCHROMOCYTOMA WITH BOTH BENIGN AND MALIGNANT COMPONENTS

A case of adrenal pheochromocytoma Is reported characterized by polygonal basophilic granular cells of benign type, plump eosinophilic granular cells of transitional type, and spindle-shaped cells of malignant type. In the primary tumor the neoplastic cells of each type revealed a distinctive topographical distribution. All gradations between the latter two varieties of cells were found, especially in the vicinity of the transitional cell area. Multiple metastases were present in the liver and lungs, where only anaplastic spindle-shaped cells could be found. Ultrastructurally, the benign cells contained predominantly large, rather light, secretory granules with a coarsely granulated core. In the malignant cells, the number, size, and intensity of granules varied considerably from cell to cell or even within a single cell. In general, the malignant cells had a higher frequency of smaller granules with electron-dense homogeneous cores. Moderate amounts of noradrenalin but not significant dopamine or adrenalin could be demonstrated from a metastatic nodule In liver. We postulate that this adrenal medullary pheochromocytoma was benign originally and underwent malignant transformation shortly before the patient's death. This is based upon the patient's clinical features and the peculiar structures of the primary tumor.     

Requirement of IL-5 for induction of autoimmune hemolytic anemia in anti-red blood cell autoantibody transgenic mice

IL-5, IL-10 and lipopolysaccharide (LPS) are known to activateB-1 cells in vivo in normal mice and anti-red blood cell autoantibodytransgenic mice (HL mice). To assess the exact role of IL-5in proliferation and activation of peritoneal B-1 cells, weanalyzed IL-5 receptor chain-deficient HL (IL-5R^–/–x HL) mice generated by the cross between IL-5R^–/–and HL mice. In IL-5R^–/– x HL mice, Ig-producingB-1 cells in the peritoneal cavity were negligible, althoughthe total number of B-1 cells in the peritoneal cavity wereas many as 30% of that in HL mice. Moreover, LPS- or IL-10-induceddifferentiation of B-1 cells into antibody-producing cells wasseverely impaired in IL-5R^–/– x HL mice. We alsoused in vivo 5-bromo-2'-deoxyuridine labeling to estimate theproliferation of B-1 cells in IL-5R^–/– mice. Theabsence of IL-5R did not affect spontaneous proliferation ofperitoneal B-1 cells. However, induced proliferation of peritorealB-1 cells by oral administration of LPS was markedly impairedin IL-5R^–/– mice. These results suggest that IL-5is required for activation-associated proliferation of B-1 cellsbut not for their spontaneous proliferation and support theidea that IL-5 plays an important role on the induction of autoantibodyproduction from B-1 cells.     

Long-term Natural Course of the Osteochondral Lesion of the Talus in a Child: A Case Report

Recent reports have described midterm natural courses of osteochondral lesion of the talus (OLT) and lack of progression of ankle osteoarthritis (OA) in adult patients. The relationship between the OLT managed with nonoperative treatment and development of OA in children remains unknown. We report the long-term course of medial OLT in a 12-year-old female who was treated nonoperatively for 10 years. Radiographically, no osteoarthritic changes were observed at the first examination. She initially returned to her basketball club after nonoperative treatment. Although daily activities were not restricted, limitation of recreational activities began to appear at 4 years of follow-up. Subsequently, plain radiographs revealed bone absorption around the osteochondral fragment and osteophyte formation at the medial gutter, then ankle OA was advanced at the final follow-up.