Inactivation of human immunodeficiency virus by high hydrostatic pressure.
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Acquired Immunodeficiency Syndrome↗
Biomedical subjects
H Ohno
Publications and source records attributed to H Ohno.
Increased growth of brown adipose tissue but its decreased lysosomal enzyme activity in heat-acclimatized, insulin-treated rats.
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Acclimatization↗
An immunoradiometric assay for thymosin alpha 1.
An Immunoradiometric assay for thymosin alpha 1(1-28) was developed using a monoclonal and a polyclonal antiserum which were raised against synthetic thymosin alpha 1(1-28) and thymosin alpha 1(16-28), respectively. A monoclonal antibody, specific for the (acetylated ser1) 1-5 sequence of thymosin alpha 1, was immobilized on polystyrene beads for the solid phase, and a polyclonal antiserum specific for the 16-28 sequence was employed. This method relies on the formation of an immune complex consisting of a 125I-labelled anti-rabbit IgG goat antibody, polyclonal antiserum, thymosin alpha 1, and the solid phase monoclonal antibody. Radioactivity on the solid phase is directly proportional to the amount of thymosin alpha 1 present in the specimen. The minimal detection limit of this assay system was approximately 1.9 pg/ml. The mean values of thymosin alpha 1 in plasma of healthy subject, ranging in age from 0 to 3 years was approximately five fold higher than that of higher ages. HPLC analysis of plasma of a healthy subjects revealed a single immunoreactive form which eluted with the same retention time as that of synthetic thymosin alpha 1. This assay will be extremely useful for the measurement of thymosin alpha 1 in biologic fluids and tissues.
Animals↗
Protein targeting by tyrosine- and di-leucine-based signals: evidence for distinct saturable components.
Targeting of transmembrane proteins to lysosomes, endosomal compartments, or the trans-Golgi network is largely dependent upon cytoplasmically exposed sorting signals. Among the most widely used signals are those that conform to the tyrosine-based motif, YXXO (where Y is tyrosine, X is any amino acid, and O is an amino acid with a bulky hydrophobic group), and to the di-leucine (or LL) motif. Signals conforming to both motifs have been implicated in protein localization to similar post-Golgi compartments. We have exploited the saturability of sorting to ask whether different YXXO or LL signals use shared components of the targeting machinery. Chimeric proteins containing various cytoplasmic domains and/or targeting signals were overexpressed in HeLa cells by transient transfection. Endogenous transferrin receptor and lysosomal proteins accumulated at the cell surface upon overexpression of chimeric proteins containing functional YXXO targeting signals, regardless of the compartmental destination imparted by the signal. Furthermore, overexpression of these chimeric proteins compromised YXXO-mediated endocytosis and lysosomal delivery. These activities were ablated by mutating the signals or by appending sequences that conformed to the YXXO motif but lacked targeting activity. Interestingly, overexpression of chimeric proteins containing cytoplasmic LL signals failed to induce surface displacement of endogenous YXXO-containing proteins, but did displace other proteins containing LL motifs. Our data demonstrate that: (a) Protein targeting and internalization mediated by either YXXO or LL motifs are saturable processes; (b) common saturable components are used in YXXO-mediated protein internalization and targeting to different post-Golgi compartments; and (c) YXXO- and LL-mediated targeting mechanisms use distinct saturable components.
Amino Acid Sequence↗
Preferential requirement of CD3 zeta-mediated signals for development of immature rather than mature thymocytes.
Antigen recognition signals by the TCR are transduced through activation motifs present in the cytoplasmic region of CD3 chains. In vitro analysis has suggested that the CD3zeta chain mediates different signals from other CD3 chains. To analyze the in vivo function of CD3zeta-mediated signals for T cell development, mice expressing a mutant CD3zeta chain lacking all the activation motifs were generated by introducing the transgene into zeta-knockout mice. Mature CD4(+) single-positive (SP) thymocytes in these mice were greater in number than in zeta-deficient mice, and the promoted differentiation was indicated by the changes of CD69 and HSA phenotypes. We found that even in the absence of activation motifs in CD3zeta, these mature cells became functional, being able to induce Ca2+ mobilization and proliferation upon stimulation. On the other hand, CD4(-)CD8(-) double-negative (DN) thymocytes, most of which were arrested at the CD44(-)CD25(+) stage similarly to those in zeta-deficient mice, could not be promoted for differentiation into CD4(+)CD8(+) double-positive thymocytes in these mice in spite of the fact that the expression of the transgene in DN thymocytes was higher than that of zeta in wild-type mice. These results demonstrate the preferential dependence of the promotion of development and/or expansion of DN thymocytes rather than mature thymocytes upon the activation signals through the zeta chain and suggest differential requirements of TCR signaling for mature SP and immature DN thymocyte developments in vivo.
Animals↗
DNA-damaging agents induce the 72-kD heat shock protein in SV40 transformed normal human fibroblasts.
In order to elucidate the involvement of DNA damage in the induction of heat shock proteins (stress proteins), we examined the induction of 72-kD heat shock protein (HSP72) in an SV40-transformed human fibroblast cell line (WI38VA13) which was exposed to various DNA-damaging agents, including 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3 -nitro-methylmethane sulfonate, N-methyl-N'-nitro-N-nitrosoguanidine, and 4-nitroquinoline-N-oxide. Induction of HSP72 was detected by the indirect immunofluorescence method using a monoclonal antibody. All the DNA-damaging agents used in this study induced HSP72 on human fibroblasts. This result indicates that DNA damage is one trigger for the induction of HSP72.
Antineoplastic Agents↗
Detection of autoantibody against 97-kD antigen by immunoblot, but not by indirect immunofluorescence, in a patient with linear IgA bullous dermatosis.
A case of linear IgA bullous dermatosis in an 85-year-old man is reported. Direct immunofluorescence (IF) of the lesional skin showed linear deposition of IgA and weak deposition of IgG at the basement membrane zone. Although no circulating autoantibody was detected by indirect IF, immunoblotting analysis using NaCl-separated normal human epidermal extracts revealed a circulating IgA antibody which bound to the 97-kD antigen.
Aged↗
p53 mutation in B-cell lymphoid neoplasms with reference to oncogene rearrangements associated with chromosomal translocations.
We investigated mutations of the p53 tumor suppressor gene in B-cell lymphoid neoplasms with reference to oncogene rearrangements associated with specific chromosomal translocations. These included 15 patients with a BCL1/PRAD1 gene rearrangement and/or PRAD1 overexpression, 45 with a BCL2 rearrangement, 2 with a BCL3 rearrangement, 24 with a BCL6 rearrangement, and 6 with both BCL2 and BCL6 rearrangements. Thirty-six patients lacked detectable oncogene rearrangements. Genomic DNA was isolated from involved tissues or leukemic cells obtained at diagnosis and/or at relapse, and established cell lines. Polymerase chain reaction-mediated single-strand conformation polymorphism analysis and direct sequencing were performed to analyze abnormalities of the p53 gene. We detected p53 gene alterations in 18 of 128 patients, representing 21 of the total 151 materials analyzed. In the total of 66 patients with an oncogene rearrangement studied at diagnosis, only one had a mutation; however, 6 of 37 patients studied at relapse showed p53 mutations. Sequential analysis revealed that the p53 mutation was closely associated with transformation from follicular lymphoma to large cell lymphoma, exclusively in BCL2-positive lymphoma cases. Two of 13 mutations observed in oncogene rearrangement-positive cases and cell lines were transitions at CpG dinucleotides. In contrast, the relationship between p53 mutations and clinical behavior in oncogene rearrangement-negative cases was variable; 5 patients including one with indolent follicular lymphoma were positive for p53 mutation at initial presentation, and 2 of the 5 showed prolonged disease-free survival. Our findings suggest that p53 alteration exhibits diverse functions in the development and progression of B-cell tumors related to the presence or absence of oncogene rearrangement, and that chemotherapy-related influences may be involved in the occurrence of progression-associated p53 mutations.
Cyclin D1↗
Relationship between rifampin MICs for and rpoB mutations of Mycobacterium tuberculosis strains isolated in Japan.
We analyzed the relationship between rifampin MICs and rpoB mutations of 40 clinical isolates of Mycobacterium tuberculosis. A point mutation in either codon 516, 526, or 531 was found in 13 strains requiring MICs of > or = 64 micrograms/ml, while 21 strains requiring MICs of < or = 1 microgram/ml showed no alteration in these codons. However, 3 of these 21 strains contained a point mutation in either codon 515 or 533. Of the other six strains requiring MICs between 2 and 32 micrograms/ml, three contained a point mutation in codon 516 or 526, while no alteration was detected in the other three. Our results indicate that the sequencing analysis of a 69-bp fragment in the rpoB gene is useful in predicting rifampin-resistant phenotypes.
Amino Acid Sequence↗
Acute cold stress induces suppressor macrophages in mice.
To elucidate mechanisms underlying acute cold stress-induced immunosuppression, functions of murine peritoneal cells of monocyte/ macrophage lineage from acute cold-stressed mice (exposed to 5 degrees C for 24 h) were investigated. Proliferative responses of spleen cells from control mice (reared at 25 degrees C) stimulated with concanavalin A (ConA) were significantly suppressed by adding peritoneal exudate cells from mice immediately after acute cold stress. The proportion of adherent cells was markedly increased in the peritoneal exudate cells from acute cold-stressed mice. These adherent cells from acute cold-stressed mice were shown to be the cells responsible for the suppressor activity for ConA responses of control spleen cells. Nonadherent cells did not suppress the ConA responses. The adherent cells in peritoneal exudate cells from control mice also suppressed the ConA responses, the inhibitory effect being considerably lower than that from acute cold-stressed mice. Addition of a nitric oxide synthase substrate analogue, NG-monomethyl-L-arginine, to the mixed cell cultures of normal spleen cells and adherent cells from acute cold-stressed mice inhibited nitric oxide release and completely abolished the suppressive effect of the adherent cells, suggesting that reactive nitrogen oxide released from the activated macrophages is apparently involved in the downregulation of proliferative responses of T cells. Thus the present findings suggest that acute cold stress induces macrophages with suppressor function and that this may contribute to the immune-suppressive state seen in spleen cells from acute cold-stressed mice.
Acute Disease↗
Glucocorticoid-mediated generation of suppressor macrophages with high density Fc gamma RII during acute cold stress.
Acute cold stress induces adherent cells with suppressor function, resulting in immunosuppression. Glucocorticoids (GC) are known as an inhibitor of the immune system and are increased by stress through stimulation of the hypothalamic-pituitary-adrenal axis. To elucidate the mechanisms underlying acute cold stress-induced immunosuppression, functions and surface phenotypes of murine peritoneal cells of the monocyte/macrophage lineage from acute cold-stressed mice (5 C for 3 or 24 h) in addition to the role of GC in the immunomodulation were investigated. Flow cytometric analysis revealed that the proportion of MAC-1+ cells with a high density of Fc gamma RII (Fc gamma RIIbright cells) was markedly increased in the peritoneal exudate cells from acute cold-stressed mice. These Fc gamma RIIbright cells were also stained with F4/80, a monoclonal antibody directed specifically against the mouse mature macrophages. The prominent suppressor activity for Concanavalin A (Con A) responses of control spleen cells was found in Fc gamma RIIbright cells, whereas MAC-1+ cells, with a low density of Fc gamma RII (Fc gamma RIIdull cells), from the stressed mice did not suppress the Con A responses. Fc gamma RIIbright cells from control mice also suppressed the Con A responses; the inhibitory effect was considerably less than that of cells from acute cold-stressed mice. As was anticipated, serum corticosterone levels were markedly increased in acute cold-stressed mice. In addition, expression of GC receptor messenger RNA was observed in Fc gamma RIIbright cells from these mice. The increase in Fc gamma RIIbright cells in peritoneal exudate cells caused by acute cold stress was inhibited by adrenalectomy or administration of a saturating amount of the GC antagonist RU 38486 (mifepristone). On the contrary, administration of the GC agonist, dexamethasone, markedly increased the proportion of Fc gamma RIIbright cells in peritoneal exudate cells of control mice. These results suggest that the generation of Fc gamma RIIbright suppressor cells of monocyte/macrophage lineage by acute cold stress was mediated to a greater or lesser degree by the action of GC through the GC receptor.
Acute Disease↗
Carotid artery disease in patients with retinal artery occlusion.
Embolization from the carotid bifurcation has been proposed as the most common cause of central retinal artery occlusion (CRAO) and branch retinal artery occlusion (BRAO). The purpose of this study was to evaluate carotid artery disease in patients with CRAO and BRAO. Using carotid ultrasonography, 17 patients (13 males, 4 females, mean age 68.7 +/- 7.1 years) with CRAO and BRAO were examined for stenotic findings and plaque morphology (homogeneous or heterogeneous) within 7 days after onset. The internal carotid artery (ICA) ipsilateral to the affected side showed a significantly higher incidence of severe carotid stenosis as compared to the non-affected side. The occurrence of heterogeneous plaques in the ICA did not differ between the affected and the non-important affected side. We suspect that severe carotid stenosis in addition to heterogeneous plaques plays an important role in retinal artery occlusion.
Aged↗
Thermogenic responses to high-energy phosphate contents and/or hindlimb suspension in rats.
Effects of chronic depletion of high-energy phosphate compounds by feeding beta-guanidinopropionic acid (beta-GPA) with or without hindlimb suspension (HS) on body temperature were studied in rats. Lower rectal and skin temperatures were observed in rats after 10 d of HS. Suspension-related enlargement of the interscapular brown adipose tissue (BAT), associated with adrenal hypertrophy, was seen. Feeding beta-GPA also caused a hypothermia and BAT enlargement. It is suggested that the hypothermic response to HS may be due to decreased contractile activity and metabolic rate in skeletal muscles, associated with stress. It is also speculated that the changes in the thermogenesis in rats fed beta-GPA might be related to a stimulated ATP synthesis with sacrificed heat production, but not associated with stress.
Animals↗
Evaluation of water durability at adhesion interfaces by peeling test of resin film.
The water durability at adhesion interfaces was investigated by measurement of the peeled area of thin resin films bonded with 4-META resin on metal surfaces after imposing thermal stress using liquid nitrogen. Thermal stress at the adhesion interface was calculated by a computer-aided finite element method. On 18-8 stainless-steel specimens which bond strongly with 4-META resin, total interface failure occurs on specimens with resin thicker than 0.55 mm in dry condition. A resin layer of 0.25 mm was chosen to study degradation of the adhesion interface by water. The shearing stress was calculated as 16 MPa for a 0.25 mm thick resin layer. On mild-steel adherent interface with 4-META resin which degrades rapidly by water molecule, the relationship between water immersion time and degradation at the adhesion interface was discussed together with the amount of water penetrated at the interface. The method proposed in the present study is effective as a quick evaluation method for water durability at the adhesion interface.
Acrylic Resins↗
Rearrangement of the 5' cluster region of the BCL2 gene in lymphoid neoplasm: a summary of nine cases.
Rearrangement of the BCL2 gene with the immunoglobulin (IG) genes is the most frequent genetic abnormality in B cell lymphoid neoplasms. In the majority of cases, breakages occur at two breakpoint cluster regions; major breakpoint cluster (MBR) and minor cluster region (mcr). In a minority of cases with non-Hodgkin's lymphoma (NHL) and chronic lymphocytic leukemia (CLL), rearrangements involving the 5' flanking region of the BCL2 (5'-BCL2) have been reported. Here, we investigated 196 patients with NHL and 31 with CLL, with regard to rearrangement of the BCL2 gene. Hybridization analyses using probes representing the three cluster regions revealed that a total of 57 patients had a rearrangement of the BCL2; 42 (73.7%) were within the MBR, seven (12.2%) were within the mcr, and nine (15.8%) had a rearrangement at the 5'-BCL2. The nine patients with 5'BCL2 rearrangement included two with follicular lymphoma, four with diffuse large cell lymphoma and immunoblastic variant, two with leukemic phase of follicular lymphoma, and one with CLL. Comigration analysis with probes for the IG heavy chain gene (IGH), kappa-chain gene (IG kappa) and lambda-chain gene (IG lambda), demonstrated a 5'-BCL2/IGH junction at the JH region in four patients with NHL derived from follicular center B cell. Thus, the 5'flanking region is a third cluster for recombination between the BCL2 and IGH, which is closely associated with the development of follicular center cell lymphoma. Molecular cloning of a 5'-BCL2/IGH junction demonstrated recombination of the two affected genes in divergent orientation. A 5'-BCL2/IG kappa junction was observed in two patients with immunoblastic lymphoma, and one with CLL had a 5'-BCL2/IG lambda recombination. Two patients, including one with a BCL2-MBR/JH junction, lacked obvious recombination of the 5'-BCL2 with IG genes, suggesting the presence of a deletion at the 5'-BCL2. Our findings demonstrated heterogeneity not only in clinicopathological presentation of B cell disease with rearrangement of 5'-BCL2, but also in molecular lesions resulting from the rearrangement.
Adult↗
[Genetic abnormalities in B cell neoplasms: special reference to diffuse large cell lymphoma].
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Chromosome Aberrations↗
Sensitivity to dexamethasone and absence of bcl-2 protein in Burkitt's lymphoma cell line (Black93) derived from a patient with acute tumor lysis syndrome: comparative study with other BL and non-BL lines.
An Epstein-Barr virus (EBV)-negative Burkitt's lymphoma (BL) cell line, designated Black93, was established in culture from a patient who developed acute tumor lysis syndrome (ATLS). Growth inhibition in vitro by dexamethasone (DXM) and the expression of bcl-2 protein (Bcl-2) were investigated in Black93 and 17 other cell lines derived from EBV-negative or -positive BL, pre-B acute lymphoblastic leukemia (ALL), follicular lymphoma (FL), and EBV-positive lymphoblastoid cell lines of normal B cell origin (B-LCL), assuming an inherent susceptibility of Black93 to cell death. The most marked growth inhibition by DXM was observed in Black93, two other BL, two pre-B-ALL and two FL lines. The other cell lines were less sensitive or were resistant. DNA extracted from the Black93 cells treated with DXM showed a ladder of oligo-nucleosomal DNA on electrophoresis. On testing of fixed smears by indirect immunofluorescence, bcl-2 protein (Bcl-2) was undetectable in Black93 and three BL lines but was detected in all the other cell lines at varying intensity. Western blot analysis showed mostly the same results. In the BL lines, the most DXM-sensitive cell lines lacked Bcl-2 expression, and the DXM-resistant cell lines always expressed Bcl-2. While none of the DXM-resistant cell lines lacked Bcl-2 expression, several pre-B or FL lines that expressed [correction of expessed] Bcl-2 were sensitive to DXM. Black93 is the first reported cell line established from a patient with ATLS. The positive sensitivity to DXM and the lack of Bcl-2 expression observed in Black93 are a major characteristic exhibited frequently by BL lines and, probably, by fresh BL cells. These properties may contribute to the precipitation of ATLS.
Acute Disease↗
Mechanisms of signal-mediated protein sorting in the endocytic and secretory pathways.
The ability to sort proteins to different intracellular compartments is an essential property of all cells. Many diseases are caused by a failure of certain proteins to be sorted properly in the endocytic and secretory pathways. In addition, various intracellular pathogens use their hosts' protein-sorting machinery at different stages of their life cycles. These facts underscore the importance of understanding the mechanisms of protein sorting at a molecular level. In this article, we review recent advances in the identification of signals that direct proteins to their correct intracellular locations and of the recognition molecules that bind to the signals. The implications of these findings for the trafficking of various proteins are discussed.
Adaptor Proteins, Vesicular Transport↗