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Biomedical subjects

H Harada

Publications and source records attributed to H Harada.

At least 397 records · Page 22Linked to original sources
PubMed1994

[A new neuromuscular transmission monitor (TOF Guard): the rationale behind the method and its clinical usefulness].

TOF Guard is one of the latest developments in the field of neuromuscular monitoring equipment. This system uses a miniature acceleration transducer (a piezo-electric ceramic wafer is used), simply fastened to the thumb with tape. The rationale behind the method is Newton's second law, stating that the acceleration is directly proportional to the force. In this study, authors assessed the accuracy of this system in clinical use, comparing with the force transducer method (Myograph 2000). The result showed that there was a very close positive correlation between the values of T1, TOF ratio and posttetanic count simultaneously measured by both methods. The coefficient of correlation was 0.96, and its significance level was P < 0.001. From the clinical view point, it is concluded that TOF Guard is very useful because of its accuracy and because the equipment is easy to handle, compact and of low price as a neuromuscular monitoring system for routine anesthesia.

Adult↗
PubMed1993

Heterogeneous expression of a novel MPC-1 antigen on myeloma cells: possible involvement of MPC-1 antigen in the adhesion of mature myeloma cells to bone marrow stromal cells.

Recent immunophenotypic analysis has shown that the heterogeneous expression of the adhesion molecule VLA-5 classifies myeloma cells into VLA-5+ mature and VLA-5- immature subpopulations. To further clarify the two myeloma subpopulations, we generated a monoclonal antibody, MPC-1, by immunizing mice with an adherent human myeloma cell line, KMS-5. The MPC-1 antibody recognized a 48-Kd surface antigen on KMS-5 but not on U-266, a nonadherent human myeloma cell line. Specificity characterization showed that MPC-1 antigen was expressed on mature myeloma cells, normal plasma cells, and mature B cells, whereas pre-B cells and germinal center B cells lacked its expression. Monocytes and a human bone marrow stromal cell line, KM102, also expressed this antigen. Two subclones of MPC-1+ VLA-5+ (KMS-5Ad) and MPC-1-VLA-5+ (KMS-5NAd) were separated from the KMS-5 cell line. The KMS-5NAd adhered to KM102 more tightly than did the KMS-5NAd, and the U-266 (MPC-1-VLA-5-) displayed almost no adherence to the KM102. The adhesion of the KMS-5Ad was partially inhibited by the MPC-1 antibody. These results, taken together, suggest that the MPC-1 antigen serves as a differentiation marker for B-lineage cells, including plasma cells, and may function as an adhesion molecule involved in the interaction of mature myeloma cells with bone marrow stromal cells.

Animals↗
PubMed1993

A missense mutation of cardiac beta-myosin heavy chain gene linked to familial hypertrophic cardiomyopathy in affected Japanese families.

A novel missense mutation of the cardiac beta-myosin heavy chain gene was detected in five unrelated Japanese patients and their affected family members with hypertrophic cardiomyopathy (HCM) by using the polymerase chain reaction (PCR)-DNA conformation polymorphism (DCP) analysis. Sequencing analysis revealed an A to G transition at codon 778 leading to replacement of the Asp residue, which is adjacent to the interaction sites of myosin heavy chain (MHC) with actin and is a conserved amino acid residue in various MHC across species, to the Gly residue. Linkage study of the mutation and two dinucleotides repeat markers of the cardiac beta-MHC gene in three affected families showed that the mutation was on the same haplotype of the cardiac beta-MHC gene and linked to HCM. These observations strongly suggest that the 778Asp to Gly mutation is the cause of HCM in these affected individuals.

Actins↗
PubMed1993

Identification of immature and mature myeloma cells in the bone marrow of human myelomas.

With regard to the expression of adhesion molecules, human myeloma cells freshly isolated from bone marrow were heterogeneous. By two-color analysis with anti-VLA-5 antibody (PE staining) and FITC-labeled anti-CD38 antibody, we found all myeloma cells located at CD38-strong positive (CD38++) fraction and identified two subpopulations among these myeloma cells: CD38++ VLA-5-(VLA-5-) myeloma cells and CD38++ VLA-5+ (VLA-5+) myeloma cells. To clarify the biologic character of these two subpopulations, the morphology, in vitro proliferative activity and in vitro M-protein secretion were examined in each fraction isolated by the purification procedure or a cell sorter. Morphologic examination showed that VLA-5- myeloma cells were mostly immature or plasmablastic and VLA-5+ cells were mature myeloma cells. Furthermore, VLA-5- myeloma cells proliferated markedly in vitro and responded to interleukin 6 (IL-6), a growth factor for myeloma cells, while VLA-5+ myeloma cells showed very low uptakes of 3H-thymidine and no responses to IL-6 but secreted higher amounts of M-protein (immunoglobulin) in vitro significantly. Therefore, we could clarify here heterogeneity of human myeloma cells in the bone marrow with regard to the expression of VLA-5, one of integrin adhesion molecules; VLA-5- myeloma cells were proliferative immature cells and VLA-5+ cells were mature myeloma cells.

ADP-ribosyl Cyclase↗
PubMed1993

Phenotypic difference of normal plasma cells from mature myeloma cells.

We have recently shown that two-color analysis with fluorescein isothiocyanate (FITC)-anti-CD38 antibody could clearly distinguish myeloma cells (plasma cells) from other hematopoietic cells in the bone marrow. Myeloma cells (plasma cells) alone were located at CD38strong positive (++) fractions. To further distinguish normal plasma cells from mature myeloma cells phenotypically, we examined immunophenotypes of normal plasma cells and myeloma cells by two-color flow cytometry with FITC-anti-CD38 antibody and phycoerythrin staining with antibody to VLA-4, MPC-1, CD44, CD56, CD19, CD20, CD24, or CD10. Normal plasma cells were all VLA-4+VLA-5+MPC-1+CD44+ CD19+CD56- in the bone marrows from seven healthy donors, tonsils from four patients with chronic tonsillitis, a spleen from one patient with idiopathic thrombocytopenic purpura, and lymph nodes from two patients with chronic lymphadenitis, respectively. On the other hand, mature myeloma cells (12 of 20 cases), VLA-4+VLA-5+MPC-1+, were all CD19- and most of them CD56+, and there were no myeloma cells with the CD19+CD56- phenotype in the 20 cases of myelomas we tested. Thus, as for the expression of CD19 and CD56, normal plasma cells from various tissues are all CD19+CD56-, whereas no myeloma cells have the CD19+CD56- phenotype. According to this finding, we investigated the expression of CD19 and CD56 on plasma cells (CD38++ fractions) in monoclonal gammopathy of undetermined significance (MGUS). Both CD19+CD56- and CD19-DC56+ plasma cells were found in all five cases of MGUS we tested, suggesting that MGUS consists of phenotypically normal plasma cells and myeloma cells. Therefore, it is reasoned that phenotypic analysis of plasma cells with anti-CD19 and anti-CD56 antibodies can distinguish normal plasma cells from malignant plasma cells (myeloma cells), and can detect malignant plasma cells even in MGUS or premyeloma states.

Aged↗
PubMed1993

Deletion of IRF-1, mapping to chromosome 5q31.1, in human leukemia and preleukemic myelodysplasia.

One of the most frequent cytogenetic abnormalities in human leukemia and myelodysplasia is an interstitial deletion within chromosome 5q. A tumor suppressor gene has been hypothesized to lie in 5q31, the smallest commonly deleted region. IRF-1, a gene whose product manifests anti-oncogenic activity, was mapped to 5q31.1. IRF-1 lies between IL-5 and CDC25C and is centromeric to IL-3 and GM-CSF. Among these genes, only IRF-1 was consistently deleted at one or both alleles in 13 cases of leukemia or myelodysplasia with aberrations of 5q31. Inactivating rearrangements of one IRF-1 allele, accompanied by deletion of the second allele, were also identified in one case of acute leukemia. Thus, IRF-1 may be a critically deleted gene in human leukemia and myelodysplasia.

Base Sequence↗
PubMed1993

Anti-oncogenic and oncogenic potentials of interferon regulatory factors-1 and -2.

Interferon regulatory factor-1 (IRF-1), a transcriptional activator, and IRF-2, its antagonistic repressor, have been identified as regulators of type I interferon and interferon-inducible genes. The IRF-1 gene is itself interferon-inducible and hence may be one of the target genes critical for interferon action. When the IRF-2 gene was overexpressed in NIH 3T3 cells, the cells became transformed and displayed enhanced tumorigenicity in nude mice. This transformed phenotype was reversed by concomitant overexpression of the IRF-1 gene. Thus, restrained cell growth depends on a balance between these two mutually antagonistic transcription factors.

3T3 Cells↗
PubMed1993

cDNA cloning of ECP40, an embryogenic-cell protein in carrot, and its expression during somatic and zygotic embryogenesis.

A cDNA of 1.2 kb was isolated from a cDNA library of embryogenic cells of carrot (Daucus carota L.) by use of nucleotide sequences that encode two internal amino-acid sequences of ECP40 (an embryogenic-cell protein with a relative molecular mass of 40,000). A genomic Southern blot using the cDNA as probe suggested that there are at least two genes for ECP40 in the carrot genome. The cDNA encoded an open reading frame of 306 amino acids, and the deduced amino-acid sequence was found to share two motifs, namely SSSSSSEDDGXGGRRKKGXXXKIKEKLXGG and EKKXXXDKIKXKLPG, with rab16 protein from rice and dehydrins from barley and maize. The level of expression of these proteins has been reported to be high during late embryogenesis and to be induced by a plant hormone, ABA. Accumulation of ECP40-specific transcripts started 18 days after flowering and continued until maturation of seeds, but the levels decreased within 24 h after imbibition. ECP40 and its mRNAs were detected in the endosperm and zygotic embryos of mature seeds by immunohistochemistry and in situ hybridization. Exogenous application of 0.1 mM ABA to carrot seedlings did not induce expression of the gene for ECP40, while drought treatment induced the accumulation of low levels of the mRNAs. During somatic embryogenesis, the mRNAs were found at high levels in embryogenic cells and at low levels in somatic embryos at the torpedo stage. Immunohistochemical analysis and in situ hybridization showed that both ECP40 and its transcripts were preferentially localized in the peripheral cells of the clusters of embryogenic cells. In somatic embryos, application of ABA resulted in increases in levels of mRNAs for ECP40 up to the levels in embryogenic cells, but no such increases were observed in ABA-treated embryogenic cells. The pattern of expression of the gene for ECP40 during somatic embryogenesis was basically the same as that of ECP31, another ABA-regulable embryogenic-cell protein of carrot, the presence of which has been correlated with the embryogenic competence of cultured cells (T. Kiyosue, S. Satoh, H. Kamada and H. Harada, Plant Physiol 95 (1991) 1077-1083). The various results together imply that a group of ABA-inducible genes is expressed in these embryogenic cells.

Amino Acid Sequence↗
PubMed1993

Secretory component and lactoferrin in pure pancreatic juice in chronic pancreatitis.

To evaluate pathophysiological roles of proteins in pancreatic secretion, immunoreactive lactoferrin (LF) and secretory component (SC) were measured in the first fraction of the pure pancreatic juice obtained endoscopically from 17 control, 21 suspected (SCP), 14 noncalcified (NCP), and 14 calcified chronic pancreatitis (CCP) subjects. The protein and amylase tended to decrease both in concentration and output from control to CCP. LF concentration was elevated in CCP (18.0 +/- 4.9 micrograms/ml) when compared with controls (2.3 +/- 0.2 micrograms/ml), and LF output in NCP (12.3 +/- 3.8 micrograms/min) was increased from controls (3.8 +/- 0.6 micrograms/min). The combination of high LF concentration with low protein output was observed in 10/14 in CCP but 0/14 in NCP and can be a biochemical discriminator of CCP from NCP. SC concentrations were also elevated in NCP (8.5 +/- 2.0 micrograms/ml) and CCP (5.6 +/- 1.6 micrograms/ml) from controls (1.2 +/- 0.2 micrograms/ml). SC outputs in SCP (9.8 +/- 3.1 micrograms/min) and NCP (21.1 +/- 4.8 micrograms/min) were increased from controls (1.7 +/- 0.3 micrograms/min), but there was no further increase in CCP. Hypersecretion of LF and SC in chronic pancreatitis is different, especially in CCP, although the mechanisms for hypersecretion are unknown.

Adult↗
PubMed1993

Detection of c-Ki-ras point mutation from pancreatic juice. A useful diagnostic approach for pancreatic carcinoma.

Cytological diagnosis of pancreatic carcinoma sometimes poses difficulties in distinguishing malignant from benign cells. Recent molecular study of pancreatic carcinoma has revealed a very high incidence of a point mutation of the c-Ki-ras oncogene at codon 12 in this neoplasm. To take advantage of this technique for the diagnosis of pancreatic carcinoma, we attempted to amplify the c-Ki-ras gene from endoscopically obtained pancreatic juice by isolation of DNA and polymerase chain reaction (PCR) coupled with restriction fragment length polymorphism (RFLP). PCR was possible in approx 70% of the cases. A point mutation was nonradioisotopically detected in 4 of 6 pancreatic carcinomas and in one intraductal papillary neoplasm, whereas no mutation was detected in other cases. Thus, this method was thought to be useful for the diagnosis of pancreatic carcinoma.

Codon↗
PubMed1993

Gut microbe of aphid closely related to its intracellular symbiont.

Pea aphid, Acyrthosiphon pisum harbors prokaryotic intracellular symbionts and, at least, two species of gut microbes. It has been shown that the aphid symbiont is more closely related to Escherichia coli than to any other free-living bacterium. Analysis of RFLP of their 16S rDNA and groE homologues suggested that one of the gut microbes is a close relative of E. coli and that the aphid symbiont is still closer to this microbe than to E. coli. In addition, the optimal temperature for the growth of this gut microbe was significantly lower than that of E. coli suggesting that this microbe has been adapted to the ambient temperature of the host insect and shares a very close ancestor with the aphid symbiont in common.

Animals↗
PubMed1993

Effects of a platelet activating factor antagonist on oedema formation following burns.

Deep dermal burns covering 30 per cent of the total body surface area were prepared by immersing the backs of rabbits in hot water at 80 degrees C for 20 s, to determine whether platelet activating factor (PAF) was involved in the onset of oedema following burns and to evaluate the effect of TCV-309, a potent PAF antagonist. The PAF antagonist, which was infused soon after the burn, blocked oedema formation in the wound and significantly (P < 0.001) inhibited PAF increase (P < 0.05) in the damaged tissue in a dose-dependent manner. This was confirmed by immunohistochemistry. In contrast, the superoxide dismutase content in the group treated with a high dose of TCV-309 was significantly (P < 0.01) higher than that of the control group. These findings suggest that administration of large doses of a PAF antagonist immediately after injury prevents oedema of burn wounds and the subsequent onset of burn shock by suppressing PAF and superoxide radical formation.

Animals↗
PubMed1993

Observer agreement and variability in measuring gastric mucosal blood flow by laser Doppler flowmetry in humans.

We evaluated the reliability (i.e. reproducibility and variability) in measuring regional gastric mucosal blood flow by laser Doppler flowmetry in a total of 32 subjects (12 normal subjects and 20 patients with cirrhosis). The measurements were performed in quadruplicate within 10 min by observer A (A1, A2) and B (B1, B2) using blind techniques. The intraclass correlation coefficient (Ri) was used to assess observer agreement. Overall, the level of intra- (Ri, 0.87 for A1 vs. A2 and 0.87 for B1 vs. B2) and interobserver agreement (0.86 for A vs. B) was excellent. In contrast, there was a higher observer variability assessed by coefficient of variation. Overall, the mean value of coefficient of variation was 12% (max. 35%) for A1 vs. A2, 12% (max. 35%) for B1 vs. B2, and 13% (max. 33%) for A vs. B. These results suggest that laser Doppler flowmetry, although the reproducibility may be clinically acceptable, seems to still be a subjective method for quantitation of gastric mucosal blood flow in humans. Therefore, studies using this method can only be acceptable when the changes that investigators intend to measure are significantly higher than the variability.

Adult↗
PubMed1993

Spontaneous and antibody directed cytotoxicity of double-negative T cells from autoimmune mice.

MRL/Mp-lpr/lpr (MRL/lpr) mice develop a syndrome similar to systemic lupus erythematosus in humans. This strain of mice is characterized by the progressive accumulation of CD4-CD8- (double-negative; DN) T cells which express increased levels of cell adhesion molecules such as CD44 and heat stable antigen (HSA). The DN T cells exhibited a higher level of spontaneous cytolytic activity and contained a higher level of serine esterase as compared with T cells of MRL/Mp-+/+ (MRL/+) mice. We also found that mAbs against CD44, Mel-14, CD45R, and HSA could augment the cytolytic activity of DN T cells of MRL/lpr mice. Antibody-mediated augmentation of cytolytic activity of DN T cells was due to conjugate formation in which the Fc portion of mAb bound to the Fc gamma receptor on target cells and the Fab portion of mAb bound to corresponding cell surface antigens on DN T cells. The antibody-mediated augmentation of cytolytic activity was not detected in T cells of MRL/+ mice and lymphokine activated killer (LAK) cells of C57BL/6 mice. In contrast, anti-CD3 mAbs could augment the cytolytic activity of DN T cells, T cells as well as LAK cells. mAbs against LFA-1 and VLA-4 failed to augment the cytolytic activity of three different effector cells. It should be noted that anti-CD3 mAb-mediated cytolytic activity of DN T cells was substantially reduced by anti-LFA-1 mAb. However, CD44, Mel-14, CD45R as well as HSA-mediated cytolytic activity of DN T cells was not inhibited by anti-LFA-1 mAb.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Monoclonal antibody G6K12 specific for membrane-associated differentiation marker of human stratified squamous epithelia and squamous cell carcinoma.

Monoclonal antibody (G6K12) specific for differentiated keratinocytes was developed using in vitro immunization against the SCC-25 cell line. G6K12 only recognized stratified portions of cultured SCC-25 cells. Immunohistochemical examination using normal human oral mucosa showed that specific G6K12-reactivity was limited to the lower spinous-cell layers, while this antibody weakly bound to cells in basal-cell layers as well as in the upper spinous, granular and cornified-cell layers. G6K12 was also reactive to keratinocytes in most moderately- and well-differentiated SCC tissues. Immunoelectron microscopic examination further demonstrated that the G6K12-immunoreactive area was at the outer surface of the entire plasma membrane, including the microvilli of stratified SCC-25. G6K12-binding was reduced 50% by the treatment of native cells with glycoendoceramidase for 2 h. These results suggest that G6K12 recognizes a plasma membrane-anchored glycoconjugate which is specific for differentiated keratinocytes.

Animals↗
PubMed1993

Extracellular ATP-induced regulation of epidermal growth factor signaling in cultured renal LLC-PK1 cells.

We investigated the effect of extracellular ATP on the interaction of epidermal growth factor (EGF) with its receptor in cultured renal epithelial cells, LLC-PK1. Pretreatment with ATP, but not adenosine, inhibited the binding of 125I-labeled EGF. The inhibition demonstrated by ATP resulted from a decrease in the affinity of EGF receptors for its ligand, with no change in the number of EGF receptors. Incubation of phorbol 12-myristate 13-acetate (PMA) for 30 min mimicked the ATP-mediated inhibition. On the other hand, prolonged pretreatment with PMA, which leads to disappearance of protein kinase C activity, reversed the inhibition. In addition, pretreatment with the protein kinase C inhibitor 1-(5-isoquinoline sulfonyl)-2-methylpiperazine prevented the ATP-mediated inhibition. ATP triggered an increase in inositol 1,4,5-trisphosphate levels and translocation of protein kinase C from cytosol to membranes, consist with the stimulation of phospholipase C and the activation of protein kinase C. These results demonstrate that extracellular ATP attenuates the ligand binding affinity of EGF receptor via the stimulation of phospholipase C, leading to the activation of protein kinase C in the LLC-PK1 cells.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗