Two Cases of Methemoglobinemia Induced by the Exposure to Nitrobenzene and Aniline

OBJECTIVE: To report two cases of methemoglobinemia induced by inhaled nitrobenzene and dermally absorbed aniline. METHODS: We have evaluated a 37-year-old male worker exposed to nitrobenzene by inhalation while conducting maintenance job of mononitrobenzene pump and a 25-year-old male worker exposed dermally to aniline while unloading. RESULTS: The first case is a 37-year-old male exposed to nitrobenzene. His blood methemoglobin concentration level was initially 19.8%, and chest X-ray was normal. After oxygen therapy, the blood methemoglobin concentration level decreased to 2.1%, and the symptoms were alleviated. The second case is a 25-year-old male exposed dermally to aniline. His chest X-ray was normal, but blood methemoglobin concentration level reached maximally 46.8%. He was treated with methylene blue due to relatively high blood methemoglobin level. Gradually after the treatment, his methemoglobin concentration level was normalized to 0.8% and simultaneously symptoms were resolved. CONCLUSIONS: After the thorough exposure investigations and medical evaluations, we have concluded that these cases were methemoglobinemia induced by occupational exposure to nitrobenzene and aniline. We suggest that businesses which handle methemoglobinemia-causing substances control the engineering process strictly, implement periodic screening, and establish emergency patient management system.

Apoptosis-Induced Gene Profiles of a Myeloma Cell P3-X63-Ag8.653

BACKGROUND: Apoptosis is a physiologic phenomenon involved in development, elimination of damaged cells, and maintenance of cell homeostasis. Deregulation of apoptosis may cause diseases, such as cancers, immune diseases, and neurodegenerative disorders. The mouse myeloma cell P3-X63-Ag8.653 (v653) is an HGPRT deficient (HGPRT) mutant strain. High dependency on de novo transcription and translation of aminopterin induced apoptosis of this cell seems to be an ideal experimental system for searching apoptosis-induced genes. METHODS & RESULTS: For searching apoptosis-related genes we carried out GE-array (dot blot), Affymetrix GeneChip analysis, Northern analysis and differential display-PCR techniques. The chip data were analyzed with three different programs. 66 genes were selected through Affymetrix GeneChip analyses. All genes selected were classified into 8 groups according to their known functions. They were Genes of 1) Cell growth/maintenance/death/ enzyme, 2) Cell cycle, 3) Chaperone, 4) Cancer/disease-related genes, 5) Mitochondria, 6) Membrane protein/signal transduction, 7) Nuclear protein/nucleic acid binding/ transcription binding and 8) Translation factor. Among these groups number of genes were the largest in the genes of cell growth/maintenance/death/enzyme. Expression signals of most of all groups were peaked at 3 hour of apoptosis except genes of Nuclear protein/nucleic acid binding/ transcription factor which showed maximum signal at 1 hour. CONCLUSION: This study showed induction of wide range of proapoptotic factors which accelerate cell death at various stage of cell death. In addition apoptosis studied in this research can be classified as a type 2 which involves cytochrome c and caspase 9 especially in early stages of death. But It also has progressed to type 1 in late stage of the death process.

Immunotherapeutic Effects of CTLA4Ig Fusion Protein on Murine EAE and GVHD

BACKGROUND: CTLA4 (CD152), which is expressed on the surface of T cells following activation, has a much higher affinity for B7 molecules comparing to CD28, and is a negative regulator of T cell activation. In contrast to stimulating and agonistic capabilities of monoclonal antibodies specific to CTLA-4, CTLA4Ig fusion protein appears to act as CD28 antagonist and inhibits in vitro and in vivo T cell priming in variety of immunological conditions. We've set out to confirm whether inhibition of the CD28-B7 costimulatory response using a soluble form of human CTLA4Ig fusion protein would lead to persistent inhibition of alloreactive T cell activation. METHODS: We have used CHO-dhfr cell-line to produce CTLA4Ig fusion protein. After serum free culture of transfected cell line we purified this recombinant molecule by using protein A column. To confirm characterization of fusion protein, we carried out a series of Western blot, SDS-PAGE and silver staining analyses. We have also investigated the efficacy of CTLA4Ig in vitro such as mixed lymphocyte reaction (MLR) & cytotoxic T lymphocyte (CTL) response and in vivo such as experimental autoimmune encephalomyelitis (EAE), graft versus host disease (GVHD) and skin-graft whether this fusion protein could inhibit alloreactive T cell activation and lead to immunosuppression of activated T cell. RESULTS: In vitro assay, CTLA4Ig fusion protein inhibited immune response in T cell-specific manner: 1) Human CTLA4Ig inhibited allogeneic stimulation in murine MLR; 2) CTLA4Ig prevented the specific killing activity of CTL. In vivo assay, human CTLA4Ig revealed the capacities to induce alloantigen-specific hyporesponsiveness in mouse model: 1) GVHD was efficiently blocked by dose-dependent manner; 2) Clinical score of EAE was significantly decreased compared to nomal control; 3) The time of skin-graft rejection was not different between CTLA4Ig treated and control group. CONCLUSION: Human CTLA4Ig suppress the T cell-mediated immune response and efficiently inhibit the EAE, GVHD in mouse model. The mechanism of T cell suppression by human CTLA4Ig fusion protein may be originated from the suppression of activity of cytotoxic T cell. Human CTLA4Ig could not suppress the rejection in mouse skin-graft, this finding suggests that other mechanism except the suppression of cytotoxic T cell may exist on the suppression of graft rejection.

Characterization of CTLA-4 Antigen Expression Identification of Molecules Composing Intracellular CTLA-4 Multiprotein Complex

BACKGROUND: CTLA-4 (Cytotoxic T Lymphocyte associated Antigen 4, CD152) has been known as a homologue of CD28, an accessory molecule providing a key costimulatory signal for successful antigen-driven activations of T lymphocyte. Most of biochemical and cell biological characteristics of the CD152 protein remain unknown while those of CD28 have been characterized in detail. METHODS: In this study CD152 expression in both CD4+ and CD8+ PBLs was studied by using flow cytometry. And intracellular CD152 multiprotein complex was purified and used for generating antibodies recognizing proteins composing of intracellular CTLA-4 multi protein complex. RESULTS: Level of surface expression of this molecule was peaked at 2 days of PHA stimulation in flow cytometric analysis. 40~45% of PHA blast cells were CD152+ in both of two subsets at this stage and the level of expression were equivalent in both two subsets. Contrary to this surface expression, intracellular expression was peaked at day 3 and it was preferentially induced in CD8+ cells and about 60% of CD8+ cells were CD152+ at this stage. High molecular weight (> 350 kD) intacellular CD152 protein complex purified by using preparative electrophoresis were immunized into rabbits and then 3 different anti-P34PC4, anti-P34PC7 and anti-P34PC8 antibodies were obtained. Using these 3 antibodies two unknown antigens associated with intracellular CD152 multiprotein complex were found and their molecular weights were 54 kD and 75 kD, respectively. Among these, the former was present as 110 kD homodimer in non- reducing condition. CONCLUSION: It seemed that 34 kD intracellular CD152 molecule forms high molecular weight multiprotein complex at least with 2 proteins of 75 kD monomer and 110 kD homodimer.

Role of N-terminal Hydrophilic Amino Acids in Molecular Translocation of CTLA-4 to Cell Surface

BACKGROUND: This study was aimed to differentiate two forms of CTLA-4 (CD152) in activated peripheral blood lymphocyte and clarify the mechanism how cytoplasmic form of this molecule is targeted to cell surface. METHODS: For this purpose we generated 2 different anti-human CD152 peptide antibodies and 5 different N'-terminal deletion mutant CTLA4Ig fusion proteins and carried out a series of Western blot and ELISA analyses. Antipeptide antibodies made in this study were anti-CTLA4pB and anti- CTLA4pN. The former recognized a region on extracellular single V-like domain and the latter recognized N'-terminal sequence of leader domain of human CD152. RESULTS: In Western blot, the former antibody recognized recombinant human CTLA4Ig fusion protein as an antigen. And this recognition was completely blocked by preincubating antipeptide antibody with the peptide used for the antibody generation at the peptide concentration of 200 ug/ml. These antibodies were recognized human CD152 as a cytoplasmic sequestered- and a membrane bound- forms in phytohemagglutinin (PHA)- stimulated peripheral blood lymphocyte (PBL). These two forms of CD152 were further differentiated by using anti-CTLA4pN and anti-CTLA4pB antibodies such that former recognized cytosolic form only while latter recognized both cytoplasmic- and membrane- forms of this molecule. Furthermore, in a transfection expression study of 5 different N'-terminal deletion mutant CTLA4Ig, mutated proteins were secreted out from transfected cell surface only when more than 6 amino acids from N'-terminal were deleted. CONCLUSION: Our results implies that cytosolic form of CTLA-4 has leader sequence while membrane form of this molecule does not. And also suggested is that at least N'-terminal 6 amino acid residues of human CTLA-4 are required for regulation of targeting this molecule from cytosolic- to membrane- area of activated human peripheral blood T lymphocyte.

Production and Characterization of Human CD27lg, CD40fg and CD95lg Fusion Proteins in Chinese Hamster Ovary Cell / 대한면역학회지

No abstract available.

Screening and Cloning of Genes Preferentially Expressed in Aminopterin-Treated Myeloma Cell Apoptosis / 대한암학회지

PURPOSE: When murine myeloma cells P3-X63-Ag8.653 (V653) of this model treated with amin opterin, an anticancer drug, they can't synthesize nucleic acid via de novo or salvage pathway and selectively eliminated due to apoptosis. This study was aimed to clone specific known and novel genes preferentially expressed in aminopteirn-treated tumor cell apoptosis. MATERIALS AND METHODS: This study was aimed to clone specific known and novel genes pre ferentially expressed in aminopteirn-treated tumor cell apoptosis by using subtraction-PCR technique. RESULTS: By using this technique 868 clones were obtained. Of these 427 clones were positive with insert DNA. By using cross-hybridization Southern blotting, final 101 clones were selected. All of these genes were sequenced and analyzed by using genebank DNA database. Total 101 clones of genes preferentially expressed in apoptotic tumor cells were classified into 10 groups, which included ribosomal proteins, nuclear proteins, mitdegrees Chondrial proteins, signal transductional proteins, retroviral proteins, cell surface receptor proteins, cell structural proteins, unclassified miscellaneous proteins, and novel genes. Especially, Unknown novel genes preferentially ex pressed in this apoptotic tumor cells included clone numbers S1-63, 1-1, 1-3, 1-16, 1-18, 1-20, 3-33, 3-41, 3-44, 3-48, 3-55, 3-60, 6-17, 6-25, 8-12, 50-7, 50-23, and 100-35. CONCLUSION: It seemed that known and unknown novel genes cloned in this study would con tribute to the future studies regarding apoptosis of tumor cells and cancer treatment therepy.

A Study on Apoptosis of HGPRT- Mouse Myeloma Cell Induced by Aminopterin, a de novo Pathway Blocking Agent / 대한면역학회지

Programmed cell death (PCD), or apoptosis, plays an important role in embryonic development, metamorphsis, hormone-dependent atrophy and tumor growth, as a physiological event regulating the cell number or eliminating damaged cells. Currently 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 a hypoxanthine guanine phosphoribosyl transferase (HGPRT) deficient mutant myeloma cell line as a fusion partner. When these rnutant cells are treated with aminopterin plus hypoxanthine-thymidine (HAT) after the cell fusion they are selectively and efficiently eliminated so that one could get only fused hybridoma cells. But there hasn't been any report regarding this selective elimination mechanism of HGPRT mutant myeloma cell. By using HGPRT myeloma V653 as a model system this study demonstrated that PCD was induced by aminopterin treatment of this V653 cell. And this PCD was further characterized by cotreatement of cycloheximide, actinomycin-D, and calcium ionophore A23187 together with aminopterin. The apoptotic endonuclease involved in this PCD process was also detected and characterized. When V653 cells were incubated for the various periods of time in the presence of 0.4 uM aminopterin, the viability was continued to decrease until 48 hours of aminopterin treatment and there was no viable cell affer 36 hours of incubation. DNA fragmentation was detectable 3 hours of incubation and peaked between 12 and 18 hours of aminopterin treatment. The induction of cell death and DNA fragmentation of V653 cells by aminopterin were inhibited by protein synthesis inhibitor, cycloheximide, and RNA synthesis inhibitor, actinomycin-D and maximal inhibitory effects on cell death were seen at concentrations of 2 ug/ml and 0.5 uM, respectively. Ca2+ ionophore A23187 promoted aminopterin-induced cell death of V653. When the cells were coincubated with A23187 in the presence of aminopterin, cell viability was remarkably decreased at concentrations of more than 2 uM and DNA fragmentation was increased at concentrations of more than 0.2 uM. A23187 also induced cell death when the cells were treated with A23187 alone. When endogenous endonuclease activities of nuclei isolated from intact healthy cells and aminopterin-treated cells were compared for four different conditions, there were notable increases in the Ca2+/Mg2+ -independent and the Mg2+ -dependent endonuclease activity after incubation with aminopterin for 12 hours. In northern blot analysis, induction of c-myc gene was observed in aminopterin-treated V653 cell reached peak at 2 hours and thern decreased drastically.

The difference of interieukin - 4 and interferon - r production of Der p I stimulated T cells and effects of immunomodulator in house dust mite sensitive atopic and non - atopic individuals / 천식및알레르기

BACKGROUND: Allergic diseases are characterized by immediate - and late - phase reactions to various allergens by the selective activation of a subset of CD4 + T cells. In response to allergen, T cells isolated from atopic donors are biased to low levels of IFN - y and high levels of IL - 4, and vice versa by T cells from non - atopic donor. Objective : The aim of this study was to evaluate the patterns of IL - 4 and IFN - y production after Der p I stimulation and the effect on the cytokine production from T cells by budesonide, disodium cromoglycate and cyclosporin A in atopic and non - atopic individuals. MATERIAL AND METHOD: Seven Der p I specific atopic and 7 non - atopic individuals were selected. We decided the 50% inhibiting concentration of each immunomodulator by lymphocyte proliferation assay, and measured their effects on the cytokine production in vitro by intracellular IL - 4, IFN - y staining and flow cytometry. Results and CONCLUSION: There was significant difference on stimulation index ( SI ) of production of IFN - y as well as IL-4 after Der p I stimulation between atopic and non-atopic individuals ( IL - 4 ; 1.57 +/- 0.7 : 0.98 +/- 0.2, p = 0.026, IFN - r : 1.45 +/- 0.5 : 0.95 +/- 0.2, p = 0.048 ). The synthesis of IL - 4, and IFN - r were significantly inhibited after the stimulation of every immunomodulators in atopic individuals, DSCG couldnt inhibit IL - 4 and IFN - r in nonatopic individuals. There was no significant difference in the inhibiting effect of these immunomodulators in both of them.

Electron Microscopic Analysis of Apoptosis of HGPRT- Mouse Myeloma Cell Induced by Aminopterin, a de novo Pathway Blocking Agent / 대한면역학회지

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.

Development of Monoclonal Antibodies Recognizing Human Peripheral Blood T Lymphocytes Cytoplasmic Proteins Induced upon Activation / 대한면역학회지

Antigen-specific T cell activation requires interaction of the T cell with specialized antigen-presenting cells. Signaling through the TCR is necessary but not sufficient to induce antigen-specific T cell activation and cytokine secretion. This first signal, termed signal 1, is both antigen-specific and MHC-restricted. Signal 2, which is neither antigen-specific nor MHC-restricted, is necessary to induce cytokine secretion, cellular proliferation, and effector function. Recently immunological studies in T cell activation area are mainly focused on biological and molecular biological characterization of TCR/CD3 complex and accessary molecules providing costimulatory signal (signal 2). If signal 2 is not delivered, T cell enter a state of long term un-responsiveness to specific antigen-termed anergy. Monoclonal antibody technique has been especially involved in recognizing novel inducible cell surface antigens on T cell activation. This study was aimed to develop monoclonal antibodies recognizing novel cytoplasmic proteins present in activated T cells. We make 6 monoclones involved in changing pattern of T cell activated cytoplasmic proteins. Using these 6 monoclonal antibodies analyze to find novel molecules involved in T cell activation associated response, apoptosis, and/or heat shock response of the T cells in early T cell activation.

Characterization of cytoplasmic Form of Human CTLA - 4 Molecule / 대한면역학회지

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.

Expression of human CTL?4 extracellular domain in escherichia coli / 대한면역학회지

No abstract available.

Detection of human CTLA-4 by using anti-peptide antibody

No abstract available.

Inhibition of IL-2 dependent DTLL-2 proliferation by immune complex from patient with ovarian cancer

No abstract available.

Effects of interferon-alpha and -gamma on lymphokine-activated killer cell activity induced by interleukin-2

No abstract available.