No abstract available.
Animals ; Asian Continental Ancestry Group* ; Cricetinae ; Cricetulus* ; Female ; Humans* ; Ovary*

CTLA-4 (=CD152), a T cell activation antigen, has been known to be homologous to CD28 in its molecular and genomic structure. Both of these two molecules are sharing their counterreceptors, B7 (CDSO) and B7-2 (CD86) and are known to play a crucial role in T cell activation. In previous our study it was reported that there are 2 forms of CTLA-4 antigen in activated human T cells, 30 kD membrane-bound form and 34 kD cytosolic-sequestered form and the former was less than 5 % of total of this antigen induced. Aims of this study are to confirm previous finding by using flow cytometry and to characterize the cytoplasmic form of human CTLA-4 by using ultrafiltration and immunoprecipitation techniques. In PHA stimulated peripheral blood lymphocyte surface expression of CTLA-4 was less than 2.1% of any of CD4+, CD8+ and CD56+ subsets. And the 34 kD form of CTLA-4 was detected in CDS+ subset only. This discrepancy confirms that 34 kD antigen is the cytoplasmic form of human CTLA-4. In ultrafiltration and subsequent Western blot analysis study this 34 kD antigen was detected in >100 kD fraction only. And in non-reducing condition this antigen formed high molecular weght complex (MW > 350 kD). In immunoprecipitation study using anti-peptide A antibody it was found that this high molecular weight complex consists of the 34 kD cytoplasmic form of CTLA-4 and previously unknown 54 kD antigen and 46 kD antigen at 1:1:8-10 ratio. And none of these 3 molecules were identified in membrane fraction of activated human T cell. The result of this study implies that CTLA-4 molecule induced upon T cell activation mainly sequestered in cytoplasrn and another signal is necessary to target this antigen on the activated T cell surface.
Antigens, CD27 ; Blotting, Western ; CTLA-4 Antigen ; Cytoplasm* ; Flow Cytometry ; Humans* ; Immunoprecipitation ; Lymphocytes ; Membranes ; Molecular Weight ; T-Lymphocytes ; Ultrafiltration

OBJECTIVE: Bacteroides fragilis, normal colonic inhabitant, is the most frequently isolated anaerobes in infected tissues, particularly in intraabdominal abscesses. In the acute infection model with abscesses, the response to B. fragilis infection is characterized by infiltration of neutrophils and macrophages. This study was designed to determine whether proinflammatory cytokines could be upregulated in peritoneal tissue of B. fragilis-infected mouse model. METHODS: After C57BL/6 mice were infected with abscess-inducing encapsulated B. fragilis, RNA was extracted from the intraperitoneal tissues. Cellular RNA was also extracted from mouse peritoneal macrophages (MPM) and human peripheral blood mononuclear cells (PBMC) after infection with B. fragilis. Expression of various cytokine mRNA was assessed using RT-PCR and standard RNA. Each cytokine protein was also measured by ELISA. RESULTS: B. fragilis-infected intraperitoneal tissues showed upregulated expression of IL-1u, IL-6 and TNFu mRNA. Expression of IL-1u and TNFu mRNA and protein was significantly higher in MPM or PBMC infected with B. fragilis than in those without infection. However, expression of IL-6 mRNA and protein was not increased in MPM or PBMC infected with B. fragilis compared with those without infection. CONCLUSION: These results suggest that the cytokines can be involved in immunopathologic reactions of the peritoneal tissue infected with B. jragilis.
Abscess ; Animals ; Bacteroides fragilis* ; Bacteroides* ; Colon ; Cytokines ; Enzyme-Linked Immunosorbent Assay ; Humans ; Interleukin-6 ; Macrophages ; Macrophages, Peritoneal ; Mice* ; Neutrophils ; RNA ; RNA, Messenger

No abstract available.
Child* ; Colon* ; Humans

Invasion of enteric bacteria, such as Salmonella and invasive E. coli, into intestinal epithelial cells induces proinflammatory gene responses and finally epithelial cell apoptosis. In this study, we asked whether invasive bacterial infection of human intestinal epithelial cells could upregulate cyclooxygenase-2 (COX-2) gene expression and whether increased COX-2 expression could influence intestinal epithelial cell apoptosis. Expression of COX-2 mRNA and prostaglandin (PG) E production were upregulated in HT-29 colon epithelial cells which were infected with S. dublin or invasive E. coli, as examined by quantitative RT-PCR and radioimmunoassay. Inhibition of COX-2 expression and PGE2 production using NS-398, a specific COX-2 inhibitor, showed a significant increase af epithelial cell apoptosis and caspase-3 activation in HT-29 cells infected with invasive bacteria. However, the addition of valerylsalicylate, a specific COX-1 inhibitor, did not change apoptosis in S. dublin-infected HT-29 cells. These results suggest that upregulated COX-2 expression and PGE2 production in response to invasive bacterial infection could contribute to host defense by inhibiting apoptosis of intestinal epithelial cells.
Apoptosis* ; Bacteria ; Bacterial Infections* ; Caspase 3 ; Colon ; Cyclooxygenase 2 ; Dinoprostone ; Enterobacteriaceae ; Epithelial Cells* ; Gene Expression ; HT29 Cells ; Humans ; Prostaglandin-Endoperoxide Synthases* ; Radioimmunoassay ; RNA, Messenger ; Salmonella

No abstract available.
HIV* ; Humans ; Humans* ; Lymphocytes* ; Zidovudine*

No abstract available.
Bacteroides fragilis* ; Bacteroides* ; Enterotoxins* ; Epithelial Cells* ; Gene Expression* ; Humans* ; Intestinal Mucosa*

PURPOSE: There is increasing awareness of the clinical importance of early detection and treatment of posterior cruciate ligament(PCL) injury. We evaluate the usefulness of Magnetic resonance(MR) imaging in the diagnosis of PCL injury. MATERIALS AND METHODS: We retrospectively analysed the MR images of 140 cases with clinically suspected knee injury. Arthroscopic or surgical correlation was available in 63 cases. We observed the finding and extent of PCL injury and other associated abnormalities. The frequency of anterior and posterior meniscofemoral ligament was evaluated. RESULTS: Eleven PCL injuries were observed, six midsubstance tears, two tibial attachment tears, two fernoral attachment tear, one laxity. The sensitivity, specificity and accuracy of MR imaging diagnosis are 100%, 98.1%, 98.4%. MR findings of PCL injury are discontinuity and focal mass formation, irregular increased signal intensity, detachment or redundancy of the ligament with avulsed bony fragment. In all cases of injured PCL, other associated abnormalities of adjacent structures were observed. Accessory anterior and posterior meniscofemoral ligaments were observed in 67.4%(87/129). CONCLUSION: MR imaging is useful in evaluation of presence or absence of PCL injury, accurate extent of PCL injury and other important associated abnormalities of adjacent structures.
Diagnosis ; Knee Injuries ; Ligaments ; Magnetic Resonance Imaging* ; Posterior Cruciate Ligament* ; Retrospective Studies ; Sensitivity and Specificity

Programrned cell death (PCD), or apoptosis, is a process by which cells die in response to specific physiological and toxicological signals. This genetically programmed form of cellular suicide is intirnately involved in many biological processes including growth, metamorphosis, embryogenesis, and oncogenesis. Cells undergoing PCD in normal and neoplasmic tissues display the following biochemical and morphological features: internucleosomal DNA fragmentation, reduced cell volume, condensed chromatin in nucleus, zeiosis and generation of apoptotic bodies containing intact organelles and plasma rnembrane. Hybridoma cell production, resulting from the fusion of myeloma cells with antibody producing spleen cells, is widely used in various fields of life science. This technique requires hypoxanthine guanine phosphoribosyl transferase (HGPRT) deficient mutant myeloma cell line as a fusion partner. When these mutants cell is treated with aminopterin plus hypoxanthine-thymidine (HAT) after the cell fusion they are selectively and efficiently eliminated remaining fused hybridoma celis. But there hasn't been any report regarding the selective elimination mechanism of this HGPRT mutant myeloma cell. By using HGPRT myeloma P3-X 63-Ag8.653 (V653) as a model system, this study demonstrated that PCD was induced by aminopterin treatment of this V653 cell line. And the sequential ultrastructural changes during this death process were observed by using electron microscope. When V653 cells were incubated with 0.4 uM aminopterin, DNA fragmentation was detectable after 3 hours and peaked between 12 and 18 hours of aminopterin treatment and the cell viability decreased in a time dependant manner. V653 cells incubated with amiopterin showed following ultrastructural changes during the death process. Dilatation of rough endoplasmic reticulum (RER) and detachment of ribosomes were the earliest ultrastructural changes and first seen after 30 minute incubation. Dilatation of perinuclear cisternae began to appear after 1 hour and deformation of nucleoplasm such as decreased electron density of perinuclear heterochromatin and increased electron density of euchromatin were seen after 3 hours. Increased electron density of cytoplasm, decreased cell volume, condensation of chromatin and apoptotic bodies were observed in many cells after 9 hours but vacuolation by severe dilatation of RER was seen in some cells. 24 hours after incubation with aminopterin, many cells showed typical form of apoptosis characterized by cell shrinkage, increased electron density of cytoplasm and apoptotic bodies. On the contrary, some cells showed different type of cell death characterized by increased cell volume, decreased electron density of cytoplasm, severely dilated RER and apoptotic bodies. In both types of cells, mitochondrial cristae and limiting membrane of mitochondria are comparatively well preserved. In other cells, nuclei did not show significant changes but there were deformations of mitochondria such as markedly increased electron density and formation of lamella bodies. The death process of V653 cell was not synchronized among cells. The results of this study proved that aminopterin-induced selective elimination of fusion partner V653 myeloma cell is due to PCD. The earliest ultrastructural changes observed in this process were dilatation of RER and detachment of ribosomes. And there were two distinct morphological types in the PCD.
Aminopterin* ; Animals ; Apoptosis* ; Biological Processes ; Biological Science Disciplines ; Carcinogenesis ; Cell Death ; Cell Fusion ; Cell Line ; Cell Size ; Cell Survival ; Chromatin ; Cytoplasm ; Dilatation ; DNA Fragmentation ; Embryonic Development ; Endoplasmic Reticulum, Rough ; Euchromatin ; Female ; Guanine ; Heterochromatin ; Hybridomas ; Hypoxanthine ; Hypoxanthine Phosphoribosyltransferase ; Membranes ; Mice* ; Mitochondria ; Organelles ; Plasma ; Pregnancy ; Ribosomes ; Spleen ; Suicide ; Transferases

PURPOSE: The purpose of this study was to compare subjective symptoms of VDT between computer-addicted and non-addicted adolescents. METHOD: A descriptive survey design was used and 646 students in one middle and two high schools were selected as participants. RESULT: The VDT subjective symptoms and degree of severity differed according to whether the students were computer-addicted or not, and in all symptoms, general, musculoskeletal, eye and mental, the mean score for subjective symptoms was higher in the addicted group than in the non-addicted group. The score for VDT subjective symptoms was highest in the addicted group for girls and students who were not healthy. The most frequent physical symptom reported by students who visited the school health room for a health problem after using the computer was headache. The most frequent type of treatment at the school health room was treatment of the symptom. CONCLUSIONS: This study suggests that students must acquire correct habits in computer use and be careful not to be addicted to the computer in order to avoid VDT syndrome. For this, educational authorities should develop computer-related health education programs and start the programs from the lower grades of elementary school.
Adolescent* ; Female ; Headache ; Health Education ; Humans ; School Health Services ; Child Health