ABSTRACT
BACKGROUND: The aging process may be induced, at least in part, by reactive oxygen species(ROS). It has been though that the lung could be a good source of ROS because it has a high oxygen tension. In the present study, we invetigated the inducibility of the first and last lines against oxidative stress, superoxide dismutases (Cu/Zn-SOD and Mn-SOD) as a scavenger of O2- and metallothionein(MT) as a scavenger of OH·, respectively, in mouse lungs with age. METHODS: Oxidative stress was induced by paraquat, an intracellular superoxide generator, at 1, 4, 8, and 12 months of age and then SODs and MT mRNAs were determined by RT-PCR method. RESULTS: The steady-state level of Mn-SOD mRNA increased from 1 to 8 months but decreased thereafter. However, Mn-SOD mRNA was not induced by paraquat after 1 month. On the other hand, there was no change in the steady-state level of Cu/Zn/-SOD mRNA, which decrease abruptly at 12 months of age. Additionally, Cu/Zn/-SOD mRNA was not induced by paraquat at any age. There was no change in the steady-state level of MT mRNA with age whereas its inducibility by paraquat was intact at all ages. CONCLUSION: These results indicate that lack of induction of SODs with age may be one of the causative factors in the aging process while induction of MT may play an important role in the defense against oxidative stress. It is therefore implicated that the tissue antioxidant/proxidant balance could be one determinants of meal life span.
Subject(s)
Animals , Mice , Aging , Hand , Lung , Meals , Metallothionein , Oxidative Stress , Oxygen , Paraquat , RNA, Messenger , Superoxide Dismutase , SuperoxidesABSTRACT
BACKGROUND: A number of theories have been proposed to explain the nature of aging process. Unfortunately, there is so far no theory that can completely explain all aging processes. In the present study, to investigate roles of inducibility of defense mechanisms by oxidative stress, cellular mRNA level of superoxide dismutases (SODs) and metallothionein (MT) as well as their inducibility by paraquat, an intracellular superoxide generator, was examined in the liver and kidney of the mice of aging process. METHODS: The steady-state levels of SODs and MT mRNA and their induction by paraquat were determined by the RT-PCR assay in male mice of 4 ages, 1, 4, 8, and 12 months. RESULTS: In the liver, the steady-state levels of Mn-SOD, Cu/Zn-SOD and MT mRNA increased until 8 months with age and decreased significantly at 12 months. Cu/Zn-SOD and MT mRNA were induced well by paraquat at all ages but Mn-SOD mRNA not at 12 months. In the kidney, their mRNA levels of Mn-SOD, Cu/Zn-SOD and MT increased with age. Mn-SOD mRNA was induced by paraquat only at 1 month but Cu/Zn-SOD mRNA not at all ages. On the other hand, MT mRNA was significantly induced by paraquat at all ages. CONCLUSION: These results suggest that SODs and MT are differentially expressed and induced according to the age and organs. In addition, it is thought that the lack of induction of Mn-SOD by oxidative stress in both the liver and kidney may be one of causative factors in the aging process while Cu/Zn-SOD and MT in the liver and MT in the kidney may play protective roles in the aging process. It is therefore implicated that the tissue antioxidant/prooxidant balance could be one of determinants of mean life span.
Subject(s)
Animals , Humans , Male , Mice , Aging , Defense Mechanisms , Hand , Kidney , Liver , Metallothionein , Oxidative Stress , Paraquat , RNA, Messenger , Superoxide Dismutase , SuperoxidesABSTRACT
BACKGROUND: Epstein-Barr virus (EBV) is closely associated with African Burkitt lymphoma, B-cell lymphoproliferative disorders arising in immunocompromised individuals, and nasopharyngeal carcinoma. Whether EBV is also associated with non-Hodgkin lymphoma (NHL) in patients without pre-existing immunocompromized status is less clear. The authors examined the clinical, morphologic, immunohistochemical features of 42 sporadic NHLs in areas of head and neck and aslo analyzed the presence of EBV genome by using polymerase chain reaction (PCR). METHODS: All lymphoma cases examined were classified according to the Working Formulation and also determined the immunophenotype using paraffin-embedded sections. For PCR, DNA was extracted from formalin fixed, paraffin-embedded tissue using chelating resin with some modifications, and processed amplification with EBV genome primers. RESULTS: Morphologically, the cases consisted of 21 diffuse large cell, 7 diffuse mixed cell, 5 large immunoblastic, 4 follicular, two small cleaved cell, two small lymphocytic and one lymphoblastic lymphoma in Working Formulation classification. Immunohistochemically, 29 cases were of B-cell lineage, 11 cases were of T-cell lineage and two cases were of non-B and non-T cell immunophenotype. EBV genome was detected in 8 of 42 cases (19%) including 3 of 29 B-cell lymphomas (10%), and 5 of 11 T-cell lymphomas (45%). CONCLUSION: These findings suggest that EBV play a role in the development of B and T-cell lymphoma.
Subject(s)
Humans , B-Lymphocytes , Burkitt Lymphoma , Classification , DNA , Formaldehyde , Genome , Head , Herpesvirus 4, Human , Lymphoma , Lymphoma, B-Cell , Lymphoma, Non-Hodgkin , Lymphoma, T-Cell , Lymphoproliferative Disorders , Neck , Polymerase Chain Reaction , Precursor Cell Lymphoblastic Leukemia-Lymphoma , T-LymphocytesABSTRACT
A human malignant lymphoid cell line(JeKo-1) was established from a Korean patient with retroperitoneal tumor presenting peripheral blood and bone marrow involvement by malignant lymphoid cells. This cell line was established from peripheral blood, and the cell line had the identical immunophenotypic features as malignant cells from the peripheral blood. The established cell line had features of a mature B-cell phenotype with no evidence for commitment to other lineages. The JeKo-1 grows in suspension with a doubling time of 33 hours. By light and electron microscopic examination, the established cells had a follicular center showing, a small, cleaved, lymphoid appearance, and had a large amount of cytoplasm containing few vacuoles and an irregular cytoplasmic membrane. Immunophenotypic analyses with monoclonal antibodies using flow cytometry showed a monoclonal IgM kappa and CD5- B-cell phenotype. The cells were non-reactive for T-cells and myeloid/monocyte antigens, and no evidence of Epstein-Barr virus nuclear antigen by polymerase chain reaction. DNA analysis showed a hypodiploid stemline with a DNA index of 0.83. The established cells were strongly reactive for bcl-2 and c-myc onco-protein, but lacked expression of multidrug resistance gene protein, p-glycoprotein by Western blot analysis. Karyotypic analysis of JeKo-1 showed 40-41 chromosomes. This cell line should be a valuable tool to study the dissemination of malignant lymphoma into the peripheral blood and bone marrow.
