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Biomedical subjects

I Otani

Publications and source records attributed to I Otani.

At least 19 recordsLinked to original sources
PubMed2004

Detecting human CD34+ and CD34- hematopoietic stem and progenitor cells using a Sysmex automated hematology analyzer.

In clinical medicine, particularly in the newly developing stem cell therapies required to support the practice of regenerative medicine, the measurement of both CD34+ and CD34- hematopoietic stem cells (HSC)/hematopoietic progenitor cells (HPC) is important in obtaining more accurate information about the total HSC/HPC content in various stem/progenitor cell sources. We report the results of an investigation into methods of detecting CD34+ and CD34- HSC/HPC using the immature information (IMI) channel incorporated into the Sysmex XE-2100 and SE-9000 automated hematology analyzers. In this study, CD34+ and CD34- HSC/HPC were separated by immunologic methods and quantified by flow cytometry (FACScan) and IMI channel analysis. In addition, CD34-/CD133+ HSC were prepared by a sequential antibody-based positive selection strategy. These cells appeared in the same area as CD34+ cells in the IMI channel of the automated hematology analyzer. These findings confirmed that an automated hematology analyzer can be used to measure both CD34+ and CD34- HSC. These results may explain the difference in HSC/HPC counts sometimes observed between the automated hematology analyzer and flow cytometric methods for CD34+ measurement. The results of this study demonstrated the potential of automated cell counting methods for measuring HSC content in cellular products for both research and clinical applications.

AC133 Antigen↗
PubMed1999

Effects of SIVmac infection on peripheral blood CD4+CD8+ T lymphocytes in cynomolgus macaques.

We have previously reported that CD4+CD8+ double-positive (DP) T cells with a resting memory phenotype exist in a substantial proportion of peripheral blood lymphocytes of adult cynomolgus macaques. In this study, we examined the effects of simian immunodeficiency virus of macaque (SIVmac) infection on DP T cells. In vitro, SIVmac239 nef-open (239) and its nef-deletion mutant replicated well in both CD4+CD8- and DP T cells. However, when the macaques were infected with 239, DP, but not CD4+CD8-, T cells were transiently increased in parallel with cell activation and viral replication, followed by depletion within 1 month postinfection. Interestingly, the nef gene was required for depletion but not for the increase and activation of DP T cells. These data suggest that the pathogenic SIV infection may downmodulate production and/or blood circulation of DP T cells by a Nef function-related mechanism(s) different from that for the depletion of CD4+CD8- T cells.

Animals↗
PubMed1999

Accumulation of MAC387+ macrophages in paracortical areas of lymph nodes in rhesus monkeys acutely infected with simian immunodeficiency virus.

We investigated the histological features of lymph nodes, focusing on monocytes/macrophages, in rhesus monkeys (Macaca mulatta) acutely infected with simian immunodeficiency virus (SIV). In monkeys infected with a pathogenic SIV, SIVmac239, MAC387(+) newly blood-derived macrophages markedly increased in number at paracortical areas at 11 to 14 days postinoculation, concomitant with the peak of the primary SIV antigenemia. The MAC387(+) macrophages densely gathered around high endothelial venules and formed cell clusters with CD3(+) T lymphocytes, tingible body macrophages, and plasmacytoid monocytes. In the cell clusters, CD3(+) T lymphocytes which closely adhered to the MAC387(+) macrophages enlarged in size, suggesting a histological manifestation of T-lymphocyte activation by macrophages. By 54 days postinoculation, when SIV antigenemia became undetectable, the MAC387(+) macrophages decreased in number and the cell cluster disappeared from paracortical areas. In contrast, the monkeys infected with a nef-deleted mutant of SIVmac239 showed lower levels of SIV antigenemia and lower numbers of MAC387(+) macrophages in paracortical areas than those infected with SIVmac239. These results indicate that MAC387(+) macrophages accumulate in paracortical areas for the period of the intense primary SIV antigenemia and may play an important role in activating naive T lymphocytes.

Animals↗
PubMed1998

Phenotypic changes in peripheral blood monocytes of cynomolgus monkeys acutely infected with simian immunodeficiency virus.

The quantitative and phenotypic changes of peripheral blood monocytes during the acute stage of simian immunodeficiency virus infection were investigated. We inoculated intravenously three cynomolgus monkeys (Macaca fascicularis) with 100 TCID50 of SIVmac239 and collected whole blood twice a week until 35 days postinoculation. We found that the relative number of monocytes in peripheral blood leukocytes significantly increased at 7-17 days postinoculation. This increase was concomitant with the peak of primary SIV antigenemia. To determine if the monocytes observed during the acute stage were phenotypically altered, they were periodically examined for the expression of surface markers (i.e., CD11b, CD14, CD16, CD29, D32, CD56, CD62L, CD64, CD80, and MHC-II-DR) by flow cytometry. The results showed that the expression levels of CD14 and CD56 on most of the monocytes were remarkably reduced at 7-17 days postinoculation, and a new subpopulation, CD14lowCD16+CD80+ monocytes, was clearly detected at 10 days postinoculation. These results indicate that the phenotypic alteration of peripheral blood monocytes occurs during the primary SIV infection.

Acute Disease↗
PubMed1998

Induction of MHC-IIDR expression on circulating CD8+ lymphocytes in macaques infected with SIVmac239 nef-open but not with its nef-deletion mutant.

We examined the expression kinetics of activation antigens CD38 and MHC-IIDR (DR) on circulating CD8+ lymphocytes in rhesus macaques infected with pathogenic simian immunodeficiency virus strain SIVmac239 nef-open (239) or its nonpathogenic nef-deletion mutant (delta nef). In the longitudinal study, we found for the first time the induction of DR expression on CD8+ lymphocytes in 239-infected macaques. The induction of DR was in parallel with an increasing viral load and a decreasing CD4+ lymphocyte level. In the macaques with the high viral load and low CD4 level, a considerable proportion of the DR+CD8+ subpopulation was CD69+, indicating an activated state. On the other hand, no significant increase in the DR+CD8+ subpopulation level was observed in delta nef-infected macaques. These data indicate that the evaluation of activation markers such as DR and/or CD69 on circulating CD8+ cells may be valuable as a surrogate marker in the SIV-macaque model.

ADP-ribosyl Cyclase↗
PubMed1998

Simian T cell leukemia virus type I-induced malignant adult T cell leukemia-like disease in a naturally infected African green monkey: implication of CD8+ T cell leukemia.

Spontaneous T cell leukemia was found in an African green monkey (Cercopithecus aethiops, AGM) naturally infected with simian T cell leukemia virus type I (STLV-I). The hematological features and the evidence for monoclonal integration of provirus DNA in the leukemic cells revealed that the leukemia was an ATL-like disease. The expression of surface markers on the leukemic cells indicated that they were defined as an activated CD8+ T cell subset. Together with the finding that seven in vitro spontaneously STLV-I-transformed cell lines were CD4-CD8+, it is likely that CD8+ T cells are transformed by STLV-I in AGMs, in contrast with human ATL. Finally, we assessed characteristics of the CD8 chains on these transformed cells. The result indicated that the leukemic cells expressed only the alpha chains but not the beta chains. However, in the case of in vitro-transformed cell lines the expression pattern of the CD8 chains varied in individual monkeys. Thus, STLV-I may preferentially transform CD8+ (both alphaalpha+ and alphabeta+) T cells in AGMs.

Adult↗
PubMed1997

Efficacy of 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG) on rhesus macaque monkeys chronically infected with simian immunodeficiency virus (SIVmac239).

To assess the therapeutic effects of 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG), a lipophilic dideoxynucleoside analogue, three rhesus macaques chronically infected with simian immunodeficiency virus (SIVmac239) were subcutaneously administered 25 mg/kg of the drug every 8 hours for 2 weeks. In two of three animals, the viral RNA in plasma and the cell-associated viral load from peripheral blood mononuclear cells were markedly decreased and the number of CD4+ and CD8+ lymphocytes were increased after 6-Cl-ddG administration. The decrease of the virus copies was associated with a reciprocal increase in the number of CD4+ lymphocytes. Additionally, a limiting dilution assay revealed a marked decrease in the lymph node cell-associated virus titer during the treatment. However, in the third monkey, the baseline of the number of CD4+ and CD8+ lymphocytes was higher than that of the other monkeys; these numbers changed very little during the treatment. In this monkey, the plasma SIV RNA level was decreased at the first week and was the same as the pretreatment level at the second week of the 6-Cl-ddG administration. In all three treated monkeys, the number of SIV RNA copies in the cerebrospinal fluid also tended to decrease during the 6-Cl-ddG treatment.

Animals↗
PubMed1997

Effects of 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG) in surface lymph nodes of rhesus monkeys (Macaca mulatta) chronically infected with simian immunodeficiency virus (SIVmac239).

We studied the effects of 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG), an antiretroviral drug, in surface lymph nodes of rhesus monkeys (Macaca mulatta) chronically infected with simian immunodeficiency virus (SIV). The rhesus monkeys were treated with 25 mg/kg of 6-Cl-ddG every 8 hr for 2 weeks. We performed sequential biopsies of the surface lymph nodes three times: before, during, and after the drug treatment. The 6-Cl-ddG dramatically decreased the number of infectious virus (measured by limiting dilution assay) in lymph node mononuclear cells. This decrease was consistent with the decrease in the number of viral RNA-positive cells in lymph nodes (analyzed by in situ hybridization). Histopathological analysis revealed that hyperplastic lymphoid follicles were reduced in size, especially, enlarged areas of centroblasts in lymphoid follicles (the so-called dark areas of germinal centers) were declined. Our results demonstrated that 6-Cl-ddG decreased the viral burden concomitantly with reduced hyper-activation of germinal centers in lymphoid follicles of SIV-infected rhesus monkeys.

Animals↗
PubMed1997

Changes in normal vaginal flora of African green monkeys (Cercopithecus aethiops) during the menstrual cycle.

Changes in normal vaginal flora of African green monkeys associated with the estrous cycle were examined by the swab method. Bacteroidaceae, corynebacteria, and streptococci were predominant throughout the whole estrous cycle, although individual differences were great. It was also clear that all bacterial species tended to decrease in the menstrual phase. Lactobacilli, the most predominant bacteria in the normal vagina of humans, were detected only in very low numbers in the African green monkey, suggesting that the normal vagina of the African green monkey has a different ecosystem from that of normal human vaginal flora.

Animals↗
PubMed1996

In vitro immortalization of Old World monkey T lymphocytes with Herpesvirus saimiri: its susceptibility to infection with simian immunodeficiency viruses.

Peripheral blood T lymphocytes of Old World monkeys, rhesus and cynomolgus monkey (Macaca mulatta and Macaca fascicularis, respectively), were successfully immortalized by infection with Herpesvirus saimiri subtype C. The T cell lines were stably cultured without addition of exogenous IL-2. The STP-C488 protein, the oncogene product of subtype C strain 488-77, was detected in these cells by Western blotting. They also expressed some markers of activated or matured T cell phenotypes such as CD2+, monkey Pan-T+, CD25+,CD29+ and MHC-II DR+. Interestingly, not only CD4+CD8- or CD4-CD8+ single positive subpopulations but also CD4+CD8+ double positive ones were present in all of them. Furthermore, they were productively infected with both SIVmac and SIVagm. The levels of the viral replication were comparable to those in human T cell lines. Thus, Herpes Virus Saimiri-immortalized Old World monkey T lymphocytes will be suitable for further studies of immune system in Old World monkeys and cell-virus interactions in SIV infection.

Animals↗
PubMed1987

Membrane stabilization of vitamin E; interactions of alpha-tocopherol with phospholipids in bilayer liposomes.

13C Spin-lattice relaxation times (T1) of 13C-labeled alpha-tocopherol in three kinds of liposomes varying in their contents of arachidoyl residues have been measured by 13C-NMR spectroscopy. On the basis of T1 values, it is proved that the segmental motion of isoprenoid side chain of alpha-tocopherol tends to increase with an increase in the distance from the chromanol moiety, and that three methyl groups attached on the aromatic ring, have some affinity to unsaturated fatty acid residues rather than those of the isoprenoid side chain. These results are incompatible with the hypothesis of Diplock et al. (1) which 4'a- and 8'a-methyl groups of isoprenoid side chain are fitted in the Z-pockets of arachidoyl chain of polyunsaturated lipids in membrane.

Animals↗
PubMed1984

Enhancement of IGE-induced mediator release from rat peritoneal mast cells by serum-treated zymosan.

Phagocytosis of zymosan (Z) treated with rat serum (ZX) by rat peritoneal mast cells caused only a small amount of [3H]serotonin release, and prior release of mediators from mast cells did not affect phagocytosis of sheep erythrocytes bearing IgG and C3b, indicating the independence of these two phenomena. When, however, mast cells were exposed to ZX, subsequent IgE-mediated release of histamine, [3H]serotonin, and beta-hexosaminidase was greatly enhanced. Prevention of complement activation by the presence of EDTA during the treatment of Z with the serum or prior heating of the serum at 56 degrees C for 30 min only slightly impaired the ability of ZX to augment mediator release, whereas prior absorption of the serum with zymosan at 0 degree C greatly diminished the enhancement. Exposure of fresh Z to variable amounts of either the acid or the high-salt eluate of ZX also generated ZX capable of enhancing [3H]serotonin release in a dose-dependent fashion. IgG, IgM, C3, and albumin were detected in the eluates by immunodiffusion. When IgG was depleted from the high-salt eluate by treating with Sepharose-anti-IgG, the enhancement was significantly reduced, indicating that IgG but not C3 or other immunoglobulins was required for the enhancement.

Animals↗
PubMed1984

Glomerular deposition and serum levels of complement control proteins in patients with IgA nephropathy.

We examined complement control proteins focusing on the role of modulating the complement activation in IgA nephropathy. Glomerular C4-binding protein (C4-bp) deposits were found in 60% of patients with IgA nephropathy, while C4 deposits were found in 30%. Glomerular deposits of beta 1H globulin (beta 1H) were found in 85% of patients with IgA nephropathy. The frequency of glomerular deposits of C4-bp tended to be higher in the group with deposits of various immunoglobulin types than in the group with deposits of IgA alone, and it increased parallel with the progression of glomerular histologic changes. The serum C4-bp level was higher in IgA nephropathy patients. No significant correlation was found between the serum level of C4-bp or beta 1H and the extent or distribution of tissue deposits of these complement control proteins. These results suggest that glomerular immune deposits in IgA nephropathy may be attributable to the activation not only of the alternative pathway but also of the classical pathway, the latter of which may take place locally in glomeruli with advanced histologic change or various immunoglobulin deposits in IgA nephropathy.

Beta-Globulins↗
PubMed1982

Phagocytosis by rat peritoneal mast cells: independence of IgG Fc-mediated and C3-mediated signals.

Phagocytosis of sheep erythrocytes (E) bearing rabbit immunoglobulin and rat C3 by rat peritoneal mast cells was quantitated by using 51Cr-labeled E and was confirmed by electron microscopy. The relative importance of IgG Fc receptor interaction in C3-mediated phagocytosis was assessed. Removal of any traces of IgG antibody by absorption of IgM antibody with protein A-Sepharose and absorption of the other reagents with sheep E had no effect on the phagocytosis of C3b- and C3bi-coated cells. IgG antibody enhanced the phagocytosis of intermediates prepared with IgM, purified components and rat C3 (EaIgMClgp4hu oxy2hu3brat) with a graded dose response, but was only additive and not synergistic with C3. The independence of the C3- and Fc-mediated signals was confirmed by using chemically produced polymers of rabbit IgG to inhibit phagocytosis. These polymers, especially tetramers and higher aggregates, completely blocked ingestion of EAIgG, but not that of EAIgMC1423b or -3bi. When IgG was substituted for IgM in the C3b intermediate, the IgG polymers inhibited about 50% of the phagocytosis. Cumulatively, the data demonstrated that in the case of rat mast cells, the stimuli to phagocytosis induced by C3 and IgG are independent; either is sufficient by itself.

Animals↗