[Cases of pseudothrombocytopenia in a mother and the newborn child].
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Adult↗
Biomedical subjects
Y Hashimoto
Publications and source records attributed to Y Hashimoto.
Synergistic effects of brain-derived neurotrophic factor and ciliary neurotrophic factor on cultured basal forebrain cholinergic neurons from postnatal 2-week-old rats.
Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, and ciliary neurotrophic factor (CNTF), a member of the neurocytokine family, are known to have synergistic effects on motoneurons, but such synergistic effect has not been studied in detail especially in the brain. In the present study, we examined the synergistic effects of BDNF and CNTF on the survival of basal forebrain cholinergic neurons cultured from postnatal 2-week-old (P2w) rats. Although BDNF is well-known to promote the survival of basal forebrain cholinergic neurons in P2w culture, CNTF had little effect on the survival of choline acetyltransferase (ChAT)-positive neurons and did not increase ChAT activity in the culture. However, CNTF enhanced BDNF-mediated promotion of cell survival of cholinergic neurons when added concomitantly. BDNF alone induced only a three-fold increase in ChAT activity in control cultures, but the concomitant addition of CNTF resulted in an eight-fold increase. CNTF did not enhance BDNF-mediated cell survival of total neurons from the basal forebrain, hippocampus or cerebellum, suggesting that the synergistic effects of CNTF on the BDNF-mediated increase of viability might be strong in basal forebrain cholinergic neurons. CNTF also enhanced the neurotrophin-4/5-mediated increase of ChAT activity, but not the nerve growth factor (NGF)-mediated one. Furthermore, the BDNF-mediated increase was also enhanced by leukemia inhibitory factor but not by interleukin-6. Similar synergistic pattern between neurotrophins and cytokines were also observed in the induction of ChAT activity in embryonic basal forebrain culture. These results suggest that TrkB, a functional high-affinity receptor of BDNF and NT-4/5, and LIFR beta, a receptor component contained in CNTF and LIF receptor complex, might be involved in the observed synergistic effects.
Acetylcholine↗
Cisplatin-induced toxicity in LLC-PK1 kidney epithelial cells: role of basolateral membrane transport.
Cytotoxicity of cisplatin was evaluated after apical and/or basolateral treatment of LLC-PK1 cell monolayers grown on porous membrane filters with 300 microM cisplatin. When LLC-PK1 cells were exposed from basolateral side for 0.5-4 h, lactate dehydrogenase (LDH) release into culture medium was markedly stimulated. However, apical treatment of the cells with cisplatin for 0.5 h did not stimulate LDH release. gamma-Glutamyltransferase activity and amount of protein in the cell homogenate were markedly decreased by basolateral treatment with cisplatin. However, in the apical treatment with cisplatin, these changes were relatively small, suggesting that degrees of the toxicities were different between basolateral and apical treatment with cisplatin. Cellular platinum level after basolateral treatment with cisplatin was higher compared to that following apical treatment. Furthermore, both accumulation and toxicity of cisplatin in LLC-PK1 cells were decreased by treatment with cisplatin at 4 degrees C. These results suggested that there were specific mechanisms mediating cisplatin uptake at the basolateral membranes of LLC-PK1 cells.
Animals↗
Identification of a novel class of retinoic acid receptor beta-selective retinoid antagonists and their inhibitory effects on AP-1 activity and retinoic acid-induced apoptosis in human breast cancer cells.
Four candidate retinoid antagonists (LE135, LE511, LE540, and LE550) were designed on the basis of the ligand superfamily concept and synthesized. Analysis of these related retinoids by transient transfection assay demonstrated that LE135, LE540, and LE550 are effective retinoic acid receptor (RAR) antagonists, whereas LE511 selectively induced RARbeta transcriptional activity. Both LE135 and LE540 inhibited retinoic acid (RA)-induced transcriptional activation of RARbeta, but not RARalpha, RARgamma or retinoid X receptor alpha (RXRalpha), on a variety of RA response elements. The retinoid antagonists also inhibited all-trans-RA-induced transcriptional activation of RARbeta/RXRalpha heterodimers, although they did not show any effect on transactivation activity of RXR/RXR homodimers. In ZR-75-1 human breast cancer cells, cotreatment of LE135 and LE540 with all-trans-RA inhibited all-trans-RA-induced apoptosis of the cells, further demonstrating that RARbeta plays a role in RA-induced apoptosis of breast cancer cells. We also evaluated the effect of these retinoids on AP-1 activity. Our data showed that LE135 and LE540 strongly repressed 12-O-tetradecanoylphorbol-13-acetate-induced AP-1 activity in the presence of RARbeta and RXRalpha. Interestingly, LE550 induced AP-1 activity when RARbeta and RXRalpha were expressed in HeLa cells but not in breast cancer cells. These results demonstrate that LE135 and LE540 were a novel class of RARbeta-selective antagonists and anti-AP-1 retinoids and should be useful tools for studying the role of retinoids and their receptors.
Animals↗
Activation of C3G guanine nucleotide exchange factor for Rap1 by phosphorylation of tyrosine 504.
C3G is a guanine nucleotide exchange factor for Rap1 and is activated by the expression of Crk adaptor proteins. We found that expression of CrkI in COS cells induced significant tyrosine phosphorylation of C3G. To understand the mechanism by which C3G is phosphorylated and activated by Crk, we constructed a series of deletion mutants. Deletion of the amino terminus of C3G to amino acid 61 did not remarkably affect either tyrosine phosphorylation or Crk-dependent activation of C3G. When C3G was truncated to amino acid 390, C3G was still phosphorylated on tyrosine but was not effectively activated by CrkI. Deletion of the amino terminus of C3G to amino acid 579 significantly reduced the Crk-dependent tyrosine phosphorylation of C3G and increased GTP-bound Rap1 irrespective of the presence of CrkI. We substituted all seven tyrosine residues in this region, amino acids 391-579, for phenylalanine for identification of the phosphorylation site. Among the substitution mutants, the C3G-Y504F mutant, in which tyrosine 504 was substituted by phenylalanine, was remarkably less activated and phosphorylated than the wild type. All the other substitution mutants were activated and tyrosyl-phosphorylated by the expression of CrkI. Thus, CrkI activates C3G by the phosphorylation of tyrosine 504, which represses the cis-acting negative regulatory domain outside the catalytic region.
Animals↗
Enzymatic inactivation of major circulating forms of atrial and brain natriuretic peptides.
We compared the enzymatic inactivation of major circulating forms of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP). Both ANP and BNP induced a significant increase in cyclic GMP (cGMP) formation in cultured epithelial cell line derived from porcine kidney, LLC-PK1. The cGMP formation stimulated by ANP in LLC-PK1 cells was significantly decreased by pre-treatment of the peptide with rat renal brush-border membranes, and the inactivation of ANP was inhibited by neutral endopeptidase inhibitors, phosphoramidon and S-thiorphan. BNP exhibited greater resistance to enzymatic inactivation than did ANP. In addition, phosphoramidon potentiated the natriuresis with a low dose (7.5 pmol min(-1) kg(-1)) of ANP but not of BNP in rats. These results suggest that enzymatic degradation of natriuretic peptides is highly dependent on peptide structure, and that the affinity of BNP to neutral endopeptidase is less than that of ANP.
Animals↗
High-level expression of uniformly 15N-labeled hen lysozyme in Pichia pastoris and identification of the site in hen lysozyme where phosphate ion binds using NMR measurements.
The non-enzymatic deamidation of Asn to Asp is known to occur in proteins and peptides and is accelerated by phosphate buffer [Tyler-Cross, R. and Schirch, V. (1991) J. Biol. Chem. 25, 22549-22556]. We attempted to identify the site in lysozyme where a phosphate ion binds by means of 1H-15N HSQC measurements of 15N-labeled lysozyme, which was successfully obtained using Pichia pastoris. As a result, we found that the phosphate ion was preferentially bound to Asn-103 in hen lysozyme. The method presented here may be useful for identifying the binding site of a protein with low molecular weight substances.
Animals↗
Nonpeptide small-molecular inhibitors of dipeptidyl peptidase IV: N-phenylphthalimide analogs.
A novel series of nonpeptide small-molecular dipeptidyl peptidase IV (DPP-IV) inhibitors with an N-phenylphthalimide skeleton has been developed. Some of the compounds, including 4-amino-(2,6-dimethylphenyl)phthalimides (7), 4- and 5-hydroxy-(2,6-diethylphenyl)phthalimide (11 and 14), 4-hydroxy-(2,6-diisopropylphenyl)phthalimide (12), and thiocarbonyl analogs of (2,6-diisopropylphenyl)phthalimide and their 4,5,6,7-tetrafluorinated derivative (18, 19 and 20), were more potent than the well-known DPP-IV-specific inhibitor, Pro-boroPro (PBP). Among them, 18 was revealed to be a DPP-IV-specific inhibitor, while the others also showed inhibitory activity toward another peptidase, aminopeptidase N (APN).
Cell Line↗
Physical and functional interactions between the transcription factor PU.1 and the coactivator CBP.
Yeast two-hybrid system was employed to isolate novel proteins that physically interact with PU.1, a member of Ets family transcription factors. Sequence analyses of several isolated clones positive for beta-galactosidase activity revealed that one of these clones was confirmed to encode a transcriptional coactivator, CREB binding protein (CBP). GST binding assay showed that the interacting sites were located at the transcriptional activation domain of PU.1 through 74-122 and the region spanning residues 1283-1915 of CBP. CBP potentiated PU.1-mediated transcription of the reporter gene driven by the multimerized PU.1-binding sites, suggesting that CBP functions as a coactivator for PU.1. Considering that CBP is a limited cellular component to function as a coactivator for several transcription factors, CBP may mediate synergistic and antagonistic interactions between PU.1 and other transcription factors during the process of hematopoietic cell differentiation.
Animals↗
Thiazolidinediones suppress endothelin-1 secretion from bovine vascular endothelial cells: a new possible role of PPARgamma on vascular endothelial function.
We examined the effect of troglitazone on immunoreactive endothelin-1 (ET-1) secretion from cultured bovine vascular endothelial cells (bVECs). Insulin (10(-9)-10(-7) M) stimulated ET-1 secretion in a dose-dependent fashion without any kinetic change. Troglitazone (1-20 microM) dose-dependently inhibited both spontaneous and insulin-stimulated ET-1 secretion. This inhibitory effect of troglitazone was associated with reduced ET-1 mRNA levels. Addition of indomethacin (100 microM) or Nw-nitro-l-arginine methyl ester (1 mM) and downregulation of protein kinase C by prolonged pretreatment of the cells with a phorbol ester, 12-O-tetradecanoylphorbol 13-acetate, did not affect the inhibitory effect of troglitazone at concentrations up to 10 microM. Troglitazone did not change the intracellular Ca2+ concentration stimulated by angiotensin II (10 microM). Other PPARgamma ligands, pioglitazone (1-10 microM) and 15-deoxy-delta 12, 14-prostaglandin J2 (1-10 microM), but not a PPARalpha ligand, bezafibrate (1-10 microM), dose-dependently suppressed spontaneous ET-1 secretion from bVECs. These results, taken together, suggest that troglitazone inhibits ET-1 mRNA expression and secretion in bVECs possibly through activation of PPARgamma. This inhibition may contribute to the hypotensive effect of troglitazone in insulin-resistant subjects.
Animals↗
GM2 gangliosidosis AB variant: clinical and biochemical studies of a Japanese patient.
OBJECTIVE: To determine the clinical features and biochemical basis of the first Japanese patient with the GM2 gangliosidosis AB variant. METHODS: The clinical manifestations and laboratory findings in the patient were investigated. Cultured fibroblasts from the patient were analyzed by means of immunofluorescence staining with an anti-GM2 ganglioside monoclonal antibody and thin-layer chromatography and immunostaining. GM1 ganglioside catabolism in cultured cells was analyzed by pulse labeling, and the amount of GM2 activator in cells was determined by Western blot analysis. Gene analysis was performed according to standard protocols. RESULTS: The patient showed progressive neurologic manifestations of quite early onset. Muscular weakness and hypotonia became evident by 1 month of age, and the patient then developed a startle reaction, severe psychomotor retardation, and myoclonic seizures. Immunocytochemical analysis clearly revealed the accumulation of GM2 ganglioside in cultured fibroblasts from the patient, and thin-layer chromatography confirmed it. Western blot and metabolic studies showed a complete deficiency of GM2 activator. Gene analysis did not reveal any mutations in the protein coding region of the GM2 activator gene. CONCLUSION: The clinical features and biochemical basis of this Japanese patient with GM2 gangliosidosis AB variant were determined. Immunocytochemical analysis using cultured fibroblasts as samples is available for the diagnosis of this disease.
Anticonvulsants↗
Polyethylene wear vector in vivo: a three-dimensional analysis using retrieved acetabular components and radiographs.
Polyethylene wear of the acetabular component can be described as one or more vectors. To help clarify the mechanisms of wear advancement in vivo, we used a combination of retrieved implants and radiographs to describe the three-dimensional wear vectors in total hip arthroplasty. The wear vectors in 41 retrieved implants from a single manufacturer were measured with use of the shadowgraph technique, and the spatial orientation of each implant was calculated from serial anteroposterior pelvic radiographs. On the basis of the combination of the wear vector in the implant and implant orientation in the pelvis, the wear vectors in vivo were determined. The mean wear vector was directed 8.1 degree lateral in the coronal plane and 4.1 degree posterior in the sagittal plane. The wear vectors in vivo showed a relatively wide range of directions, not necessarily coinciding with the commonly presumed resultant force in the hip. The wear vectors were not associated with the spatial orientation of the acetabular components, but cups with impingement demonstrated more anterior wear than did those without impingement. Our results suggest that the process of polyethylene wear is not as simple as previously described and that several factors influence advancement of wear in vivo.
Acetabulum↗
Optimal distances for squirrels to transport and hoard walnuts.
Walnuts, Juglans airanthifolia, are an important food item for Japanese squirrels, Sciurus lis, which hoard them for later use. We set up feeders in small walnut patches in secondary forest, mounted radiotransmitters on nuts, placed them on the feeders and tracked them when they were cached. Of 720 nuts placed on the feeders over a 3-year period, 32.6% were eaten immediately and 50.6% were scatter-hoarded 0-168 m from the feeders. With increasing distance to the cache site, the squirrels took longer to return to the feeders (range 0.35-35 min). However, the further away a cache was, the less likely it was to be stolen by conspecifics or other nut-eating animals: nuts we hoarded ourselves disappeared more quickly from near the source trees. Squirrels took nuts further away later in the season when caches were lost at a higher rate. Using a simple model maximizing the rate of energy gain per unit time taken to search for and hoard the nuts at different distances from the source, we discuss whether squirrels alter the transport distance of hoarding nuts according to cache survival rate and/or nut availability. Copyright 1999 The Association for the Study of Animal Behaviour.
Journal Article↗
Abnormal thymic expression of epithelial cell adhesion molecule (EP-CAM) in New Zealand Black (NZB) mice.
New Zealand Black (NZB) mice have been well documented to have a variety of thymic epithelial cell microenvironmental abnormalities, including disruption of corticoepithelial cell networks and medullary cell clusters. These abnormalities of the thymic stromal network are particularly important because similar observations have been noted in other models of murine lupus. Thymic epithelial cells, a key component of the microenvironment, play an important role in selection of the mature T cell receptor repertoire. Recently, a homotypic calcium-independent human and murine epithelial cell adhesion molecule, Ep-CAM, has been described which is located at the thymocyto-cortical cell junction. The function of Ep-CAM is still unclear but its unique location within the thymus suggests that it is critical in the process of providing maturation signals. Consequently, we examined the thymic expression of Ep-CAM in a series of autoimmune prone mice by thymic distribution of Ep-CAM in NZB, NZW, NZB/W, BXSB-Yaa, MRL- lpr/lpr, C3H- gld/gld and the control strains BALB/c, C57BL6, C3H and MRL(+/+), by immunohistology and flow cytometry. Interestingly, NZB mice are similar to control mice from day 4 to 2 weeks of age, having a very low expression of Ep-CAM at the thymocyto-cortical junction. In control strains, there is a marked increased in expression of Ep-CAM beginning at 5 weeks of age. In contrast, NZB mice fail to show significant expression of Ep-CAM even well into adulthood. This abnormality of NZB mice was also noted in NZB/W F1 and BXSB mice, but not MRL- lpr/lpr or C3H- gld/gld mice. Given the potential importance of Ep-CAM in thymic selection, this study provides important evidence that a defective stromal microenvironment is likely to be of etiological significance in the susceptibility of NZB to autoimmune disease.
Animals↗
Glucocorticoids inhibit proliferation and adhesion of the IL-3-dependent mast cell line, MC/9, to NIH/3T3 fibroblasts, with an accompanying decrease in IL-3 receptor expression.
We investigated the effects of glucocorticoids on IL-3-dependent proliferation and c-kit expression of cells of the mouse mast cell line, MC/9. Glucocorticoids (dexamethasone, prednisolone, and hydrocortisone) inhibited IL-3-dependent MC/9 cell proliferation, whereas sex steroids (progesterone, beta-estradiol, and testosterone) had no effect. Flow cytometric analysis revealed that glucocorticoids reduced the expression of the IL-3 receptor on MC/9 cells. Immunoblot and Northern blot analyses indicated that glucocorticoids also reduced the expression of both c-kit protein and c-kit mRNA transcript. Furthermore, the adhesion of MC/9 cells to stem cell factor-expressing NIH/3T3 cells was reduced following glucocorticoid treatment. Our results indicate that glucocorticoids inhibit IL-3-dependent MC/9 mast cell proliferation, with an accompanying decrease in IL-3 receptor expression. Glucocorticoids also reduced c-kit expression on MC/9 cells resulting in a decreased adhesion to NIH/3T3 fibroblasts.
3T3 Cells↗
Nausea and vomiting induced by arterial chemo-embolization in patients with hepatocellular carcinoma and the antiemetic effect of ondansetron hydrochloride.
To determine the incidence of nausea and vomiting and the antiemetic effect of ondansetron hydrochloride (OND) in patients with hepatocellular carcinoma treated with arterial chemo-embolization, we studied 59 patients with hepatocellular carcinoma who were treated with transcatheter arterial embolization (TAE) or lipiodolized transcatheter arterial infusion (L-TAI). We investigated the incidence of nausea and vomiting and the amount of food intake when TAE or L-TAI was performed. All patients who experienced nausea and vomiting received OND administered prophylactically at the time of the next TAE or L-TAI to evaluate the antiemetic effect of the drug. Cumulative rates of nausea and vomiting during the week following arterial chemo-embolization were 44.8% and 27.6%, respectively. There was a tendency for the incidence to be higher in patients treated with the anticancer agent zinostatin stimalamer (SMANCS) than in those treated with epirubicin hydrochloride (EPI). Regarding food intake, 53.1% of the patients stated that they ate "half or more than half" of the food provided on the day of arterial chemo-embolization. The rate improved as time went on. In 5 patients who experienced nausea and vomiting at the time of arterial chemo-embolization, nausea and vomiting were inhibited satisfactorily by OND. When arterial chemo-embolization was performed, antiemetic treatment for approximately 3 days was necessary to improve patients' quality of life (QOL) to an acceptable level, and OND was found to be effective for the purpose in our 5 patients who had experienced nausea and/or vomiting at the previous treatment.
Adult↗
Identification of a rat invariant T-cell receptor; alpha chain similar to mouse V alpha 14-J alpha 281 and human V alpha 24-J alpha Q.
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Amino Acid Sequence↗
Multiple lymphomatous polyposis of the gastrointestinal tract is a heterogenous group that includes mantle cell lymphoma and follicular lymphoma: analysis of somatic mutation of immunoglobulin heavy chain gene variable region.
Multiple lymphomatous polyposis (MLP) is characterized by multiple polyps involving long segments of the gastrointestinal (GI) tract. MLP is thought to represent mantle cell lymphoma (MCL) of the GI tract; however, some cases of follicular lymphoma (FL) of the GI tract are found with a multiple polypoid appearance. In the present study, to clarify the cellular origin of MLP, clonal immunoglobulin heavy chain (IgH) gene rearrangement of four cases with MLP was amplified by polymerase chain reaction (PCR) and analyzed for the presence of somatic mutation. The IgH variable (VH) region sequences of three cases (CD5+ CD10- cyclin D1+) showed a little somatic mutation compared with the closest published germline. The other case (CD10+ CD5- cyclin D1-) was highly mutated and showed intraclonal heterogeneity (ongoing somatic hypermutation). These data indicate that three of the cases with MLP are derived from pregerminal center B cells (mantle zone B cells) and one case with MLP from germinal center B cells. Our study suggests that MLP is a heterogenous group that includes MCL and FL.
Adult↗