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Biomedical subjects

Hideki Nakayama

Publications and source records attributed to Hideki Nakayama.

At least 19 recordsLinked to original sources
PubMed2007

ADAM-17 associated with CD44 cleavage and metastasis in oral squamous cell carcinoma.

ADAM-17 (a disintegrin and metalloproteinase 17) is a membrane-anchored protein, which can cleave the ectodomain in a variety of transmembrane proteins. In the in vitro experiments with tumor cells, ADAM-17 is reported to cleave CD44, an adhesion molecule that interacts with hyaluronic acid, to promote tumor cell migration. In the present study, we examined ADAM-17 expression and CD44 cleavage in specimens from 50 patients diagnosed to have oral squamous cell carcinoma (SCC). Each specimen was divided into two pieces, one was studied by immunohistochemistry and the other was subjected to a Western blot. By coordinating the results of both analyses, ADAM-17 expression was evaluated to be high in 23 cases (46%). When CD44 cleavage was also studied by immunohistochemical staining as well as with Western blotting, CD44 cleavage was judged to be positive in 29 cases (58%). When the ADAM-17 expression level was compared with the CD44 cleavage state, most of the cases expressing high levels of ADAM-17 (87%) showed positive CD44 cleavage. The level of ADAM-17 expression was significantly correlated to the nodal metastasis and local recurrence in oral SCC. Our findings suggest that ADAM-17 is involved in CD44 cleavage and contributes to tumor progression in oral SCC.

ADAM Proteins↗
PubMed2006

Long-term outcome of infants with twin-to-twin transfusion syndrome.

OBJECTIVE: To clarify the long-term neurodevelopmental outcome of twin-to-twin transfusion syndrome (TTTS) survivors. METHODS: From January 1994 to December 2003, 33 newborns with TTTS who were derived from 18 monochorionic twin gestations were enrolled for the study. The development and growth at 3 or 6 years of age were compared between TTTS survivors and weight-matched singleton controls. RESULTS: The mortality in TTTS (8/33: 24%) was significantly higher than that of the controls (7/80: 9%). Of all 12 TTTS patients who were diagnosed before 25 weeks and born before 28 weeks of gestation, in 10 (83%) it led to neonatal or intrauterine death. The morbidity of cerebral palsy, epilepsy, and mental retardation did not differ between TTTS and control patients. The morbidity and severity of neurological deficits at school age were similar in both groups. No growth parameters at 3 or 6 years of age differed between TTTS and controls. CONCLUSIONS: Morbidity, growth and development of TTTS survivors attained comparable levels of weight-matched controls, despite the higher neonatal mortality. These results suggest that the early management of TTTS is critical for refining the total outcome of the affected twins.

Child Development↗
PubMed2006

Nonimmune hydrops fetalis due to generalized lymphatic dysplasia in an infant with Robertsonian trisomy 21.

We report the first case of generalized lymphatic dysplasia and trisomy 21 presenting with nonimmune hydrops fetalis. This infant showed intractable chylothorax, chylous ascites, and periodic bouts of edema. A karyotype analysis revealed Robertsonian trisomy 21: 46,XY,t(14q21q)(q10;q10) +21. This patient died of multiple organ failure at 400 days of life, despite the management of chylous effusions. The lymphoscintigraphy and histopathological findings led to the final diagnosis of generalized lymphatic dysplasia, which might also contribute to the development of hydrops. Refractory chylothorax in trisomy 21 patients may emphasize the need for intensive scrutiny of lymphatic disorders.

Adult↗
PubMed2006

High-efficiency secretory production of peroxidase C1a using vesicular transport engineering in transgenic tobacco.

Horseradish peroxidase isozyme C1a (HRP C1a) is widely used as a reporter enzyme in a variety of detection procedures such as enzyme-linked immunosorbent assay (ELISA) and western blotting. We previously isolated the gene encoding HRP C1a and showed that HRP C1a is at first translated as a preproprotein containing propeptides at its N- and C-termini (N-terminal secretion signal peptide and C-terminal propeptide; CTPP). The signal peptide (sp) is necessary for endoplasmic reticulum (ER) translocation and the CTPP acts as a vacuolar sorting determinant. Furthermore, HRP C1a was secreted into the culture medium from cells expressing the HRP C1a gene without the CTPP region. We optimized the secretory production system of HRP C1a in tobacco plants. To determine a suitable signal peptide for high-efficient secretion of proteins, three types of sp derived from HRP C1a (C1Psp), beta-D-glucan exohydrolase (GEsp) and 38 kDa peroxidase (38Psp) were compared. GE and 38P are secretory proteins highly accumulated in the culture medium of BY2 cells. The secretion efficiency was increased by 34% and 53% when GEsp and 38Psp was used, respectively. Next, we used a translational enhancer, the 5'-untranslated region of Nicotiana tabacum alcohol dehydrogenase gene (NtADH 5'-UTR). The production of HRP C1a was increased by placing NtADH 5'UTR in front of the ORF in BY2 cells. These results indicate that the localization and expression level of recombinant proteins can be controlled by the use of propeptides and 5'UTR, respectively. Finally, high-efficiency secretory production of the HRP C1a was also achieved in transgenic tobacco.

5' Untranslated Regions↗
PubMed2005

The formulation of the control of an expression pattern in a gene network by propositional calculus.

In this study we model a gene network as a continuous-time switching network. In this model, each gene has a binary state which indicates if the gene expresses or not. We propose a method to control a sequence of expression patterns in the gene network model by adding another continuous-time switching network. By using propositional calculus, we will show that the control problem can be formulated as a mixed-integer linear programming problem with linear constraints.

Animals↗
PubMed2005

Thrombocytosis in preterm infants: a possible involvement of thrombopoietin receptor gene expression.

Transient thrombocytosis is commonly observed in preterm infants after birth, but its physiological mechanism is still unknown. To understand the mechanism of the transient thrombocytosis in preterm infants we firstly evaluated a correlation between platelet counts and thrombopoietin (TPO) levels in preterm infants and next c-mpl mRNA levels on platelets in healthy preterm infants longitudinally during a half-year of life. The mean platelet counts in 45 very low birth weight infants (mean gestational age 27.4+/-1.8 weeks, mean birth weight 1047+/-249 g) was 230+/-71x10(9)/l just after birth and thereafter gradually increased to 579+/-178x10(9)/l by 5 weeks of age. The platelet counts continued this level for about next 8 weeks. Serum TPO levels soon after birth and at 1 month of age were significantly higher than those at the age of 2-6 months. There was a significant negative correlation between platelet counts and serum TPO values. The c-mpl expression levels on platelets at birth and at 1 month of age tended to be lower than those on platelets from adults, and the c-mpl levels gradually increased through 6 months of age, although they were still lower than those of adults. Our results suggest that low expression of TPO receptor on platelets until 1 month after birth cause a decreased TPO clearance and keep a high level of free TPO in blood, thereby promoting platelet production from megakaryocytes or their progenitors in bone marrow, resulting in the subsequent thrombocytosis in preterm infants.

Adult↗
PubMed2005

Prognostic factors for relapsed childhood acute lymphoblastic leukemia: impact of allogeneic stem cell transplantation--a report from the Kyushu-Yamaguchi Children's Cancer Study Group.

BACKGROUND: The treatment results of childhood acute lymphoblastic leukemia (ALL) with a first relapse were retrospectively analyzed to determine prognostic factors. In particular, an attempt was made to clarify whether stem cell transplantation (SCT) had any advantages over chemotherapy. PROCEDURES: Of the 407 children with ALL diagnosed between 1984 and 1996, 117 suffered from a relapse before December 1999. The patients were treated differently according to the protocols of each institution. The potential prognostic factors examined were: the time of initial diagnosis, gender, immunophenotype of leukemic blasts and the NCI-risk classification at initial diagnosis, the site of relapse, the time of relapse (early: within 18 months after diagnosis, intermediate: other than either early or late relapse, late: later than 6 months after the discontinuation of front-line chemotherapy), and the treatment after relapse (chemotherapy alone and SCT). RESULTS: A second complete remission (CR2) was achieved in 90 patients (77%) and thirty of them maintained CR2, thus resulting in an event-free survival rate (EFS) of 25.1% and an overall survival rate of 26.1%. The significant prognostic factors identified by a multivariate analysis included the time of relapse (EFS: early 16.2%, intermediate 23.9%, late 35.1%, P = 0.012) and the treatment after relapse (EFS: SCT 30.3%, chemotherapy 22.0%, P = 0.049). When patients with an isolated bone marrow relapse and continuous CR2 for more than 3 months were analyzed, the treatment in CR2 was the only independent prognostic factor (EFS: SCT 60.2%, chemotherapy 25.7%, P = 0.005). CONCLUSIONS: In children with ALL and a first relapse, the time of relapse and the treatment after relapse were found to be independent prognostic factors. Allogeneic SCT in CR2 showed significantly better results than chemotherapy in patients with an isolated bone marrow relapse.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

Effects of IkappaB kinase alpha on the differentiation of squamous carcinoma cells.

IkappaB kinase (IKK) alpha and beta share the function to phosphorylate IkappaB to activate a transcription factor NF-kappaB. Recent reports, however, revealed differences in the functions of the two kinases. The present study was designed to determine a unique function of IKKalpha on the differentiation of squamous cell carcinoma (SCC). Transfection with IKKalpha gene, but neither IKKbeta nor NF-kappaB gene, inhibited the constitutive expressions as well as extracellular calcium-induced expressions of involucrin and filaggrin, epithelial differentiation markers, in cultured SCC cells. Morphological changes from polygonal to fibroblastic shape were seen in the SCC cells stably expressing green-fluorescent protein (GFP)-fused IKKalpha while intracellular localization of GFP-IKKalpha differed from that of GFP-IKKbeta. Interestingly, phorbol myristate acetate together with IKKalpha gene transfection strongly inhibited the expression of involucrin in SCC cells and induced the phosphorylation of serine residue in IKKalpha, suggesting that protein kinase C is involved in the effect of IKKalpha on the differentiation of SCC cells. In conclusion, high expression of IKKalpha may serve as an intracellular signal to halt the epithelial differentiation of SCC cells.

Carcinoma, Squamous Cell↗
PubMed2004

Yeast plasma membrane Ena1p ATPase alters alkali-cation homeostasis and confers increased salt tolerance in tobacco cultured cells.

In plants, the plasma membrane Na(+)/H(+) antiporter is the only key enzyme that extrudes cytosolic Na(+) and contributes to salt tolerance. But in fungi, the plasma membrane Na(+)/H(+) antiporter and Na(+)-ATPase are known to be key enzymes for salt tolerance. Saccharomyces cerevisiae Ena1p ATPase encoded by the ENA1/PMR2A gene is primarily responsible for Na(+) and Li(+) efflux across the plasma membrane during salt stress and for K(+) efflux at high pH and high K(+). To test if the yeast ATPase would improve salt tolerance in plants, we expressed a triple hemagglutinin (HA)-tagged Ena1p (Ena1p-3HA) in cultured tobacco (Nicotiana tabacum L.) cv Bright Yellow 2 (BY2) cells. The Ena1p-3HA proteins were correctly localized to the plasma membrane of transgenic BY2 cells and conferred increased NaCl and LiCl tolerance to the cells. Under moderate salt stress conditions, the Ena1p-3HA-expressing BY2 clones accumulated lower levels of Na(+) and Li(+) than nonexpressing BY2 clones. Moreover, the Ena1p-3HA expressing BY2 clones accumulated lower levels of K(+) than nonexpressing cells under no-stress conditions. These results suggest that the yeast Ena1p can also function as an alkali-cation (Na(+), Li(+), and K(+)) ATPase and alter alkali-cation homeostasis in plant cells. We conclude that, even with K(+)-ATPase activity, Na(+)-ATPase activity of the yeast Ena1p confers increased salt tolerance to plant cells during salt stress.

Adenosine Triphosphatases↗
PubMed2004

Characteristic expression of aryl hydrocarbon receptor repressor gene in human tissues: organ-specific distribution and variable induction patterns in mononuclear cells.

To investigate the expression of aryl hydrocarbon receptor repressor (AhRR) and related molecules in various tissues and the effects of aromatic hydrocarbons (AHs) on their expression, we developed a reliable technique of quantification of human AhRR as well as aryl hydrocarbon receptor (AhR), AhR nuclear translocator (ARNT) and cytochrome P450 1A1 (CYP1A1) mRNA by real-time TaqMan PCR method. First, we examined the expression of these genes in human adult or fetal tissues. The levels of AhRR expression were extremely high in testis, very high in lung, ovary, spleen and pancreas from adults, whereas those were low in those from fetuses. On the other hand, CYP1A1 expression was extremely high in lung, and AhR and ARNT were ubiquitously expressed in almost all tissues. Second, we compared the expression levels of these genes in mononuclear cells (MNCs) from various sources. Comparison of the basal expression levels of these genes in MNCs demonstrated that MNCs from umbilical cord blood showed higher AhRR or CYP1A1 expression than those from adults. The induction of AhRR or CYP1A1 expression by 3-methylcholanthrene (3-MC) was observed in MNCs from adults but not from umbilical cord blood. Consequently, there existed characteristic differences in the basal levels of AhRR and CYP1A1 expression in MNCs, as well as in their inducibility by 3-MC among MNCs from various types of human bloods. These results will provide basic information for a possible application of AhRR and CYP1A1 measurements to evaluate AH exposure in vivo.

Adult↗
PubMed2004

CD25+CD4+ T cells in human cord blood: an immunoregulatory subset with naive phenotype and specific expression of forkhead box p3 (Foxp3) gene.

OBJECTIVE: To address the role of cord blood (CB) CD25+CD4+ T cells, the gene expressions and function of this subset were analyzed. MATERIALS AND METHODS: CD25+CD4+ T cells fractionated from CB of term and preterm infants were subjected to flow cytometry, quantitative polymerase chain reaction analysis for cytokines, costimulatory molecules, and transcription factors, and functional assays. RESULTS: Human preterm CB contained a high proportion of CD25+CD4+ T cells that declined with gestational age to the level of adult peripheral blood (PB). CD25+ or CD25-CD4+ T cells in CB had a higher frequency of CD45RA+ and CD38+ cells than in PB. CB CD25+CD4+ T cells less frequently expressed CD45RO, CD71, and HLA-DR than PB CD25+CD4+ T cells, despite similar expressions on CB and PB CD25-CD4+ T cells. No expression of IL-10, transforming growth factor-beta, interleukin-4, and interferon-gamma mRNA differed between CB CD25+CD4+ and CD25-CD4+ T cells, in contrast to the high interleukin-10 expression in PB CD25+CD4+ T cells. CTLA-4 was more transcribed in CB and PB CD25+CD4+ T cells than in the counterpart CD25-CD4+ T cells. CD28 or ICOS was similarly expressed in CB and PB T cells. CB CD25+CD4+ T cells effectively suppressed the proliferation of CB CD25-CD4+ T cells in a dose-dependent manner. Human CB and PB CD25+CD4+ T cells preferentially transcribed Foxp3, which governs the regulatory function of this subset in mice. CONCLUSIONS: These results suggest that CB contains CD25+CD4+ regulatory T cells as a functionally mature population with naive phenotype. This subset may naturally arise and decline in fetus to play a potential immunoregulatory role in intrauterine life.

Animals↗
PubMed2004

NF-kappaB involvement in tumor-stroma interaction of squamous cell carcinoma.

We investigated the interaction between tumor cells and stromal fibroblasts in tumor invasion of oral squamous cell carcinoma. Gelatin zymography showed that high levels of matrix metalloproteinase (MMP)-9 were present in the tissue of squamous cell carcinoma. When tumor cells and fibroblasts were isolated from the tissue and cultured separately, significant levels of MMP-9 were lost in the culture media of tumor cells as well as fibroblasts. When tumor cells and fibroblasts were cocultured in the presence of tumor necrosis factor alpha, high levels of MMP-9 were recovered in the culture media. The levels of MMP-9, which were secreted from tumor cells, but not fibroblasts, correlated with the number of cocultured fibroblasts. Cocultured fibroblasts, moreover, enhanced the induction of an active form of MMP-9, cell motility, and the activation of a transcription factor NF-kappaB in tumor cells. Stromal fibroblasts may induce NF-kappaB activation and promote the invasion of oral squamous cell carcinoma.

Carcinoma, Squamous Cell↗
PubMed2004

Overexpression of NtHAL3 genes confers increased levels of proline biosynthesis and the enhancement of salt tolerance in cultured tobacco cells.

The Hal3 protein of Saccharomyces cerevisiae inhibits the activity of PPZ1 type-1 protein phosphatases and functions as a regulator of salt tolerance and cell cycle control. In plants, two HAL3 homologue genes in Arabidopsis thaliana, AtHAL3a and AtHAl3b, have been isolated and the function of AtHAL3a has been investigated through the use of transgenic plants. Expressions of both AtHAL3 genes are induced by salt stress. AtHAL3a overexpressing transgenic plants exhibit improved salt and sorbitol tolerance. In vitro studies have demonstrated that AtHAL3 protein possessed 4'-phosphopantothenoylcysteine decarboxylase activity. This result suggests that the molecular function of plant HAL3 genes is different from that of yeast HAL3. To understand the function of plant HAL3 genes in salt tolerance more clearly, three tobacco HAL3 genes, NtHAL3a, NtHAL3b, and NtHAL3c, from Nicotiana tabacum were identified. NtHAL3 genes were constitutively expressed in all organs and under all conditions of stress examined. Overexpression of NtHAL3a improved salt, osmotic, and lithium tolerance in cultured tobacco cells. NtHAL3 genes could complement the temperature-sensitive mutation in the E. coli dfp gene encoding 4'-phosphopantothenoyl-cysteine decarboxylase in the coenzyme A biosynthetic pathway. Cells overexpressing NtHAL3a had an increased intracellular ratio of proline. Taken together, these results suggest that NtHAL3 proteins are involved in the coenzyme A biosynthetic pathway in tobacco cells.

Amino Acid Sequence↗
PubMed2004

[Three cases of organophosphate poisoning treated with pralidoxime iodide and whole-bowel irrigation].

We encountered three cases of organophosphate poisoning treated with pralidoxime iodide (PAM) and whole-bowel irrigation without atropine sulfate. All patients recovered without persistence or recurrence of toxic symptoms and without any somatic after effects. In case 1, a 48-year-old woman ingested approximately 5 g of ethylthiometon in a suicide attempt. She was transferred to the hospital because of cardiopulmonary arrest. After resuscitation, she was transferred to our center. She was placed on a ventilator and received i.v. PAM and polyethylene glycol-electrolyte through a nasojejunal tube for whole-bowel irrigation. Six days later, serum ChE was improved. In case 2, a 51-year-old man ingested approximately 30 g of malathion in a suicide attempt and was transferred to our center because of dyspnea. He was treated with PAM and whole-bowel irrigation, but did not require a respirator. Serum ChE already showed improvement the following day. In case 3, a 31-year-old man ingested approximately 50 g of DEP in a suicide attempt and was transferred to our center because of unconsciousness. He was treated with a respirator, PAM and whole-bowel irrigation. Serum ChE improved within two days. These cases suggest the possibility that preferential whole-bowel irrigation without atropine sulfate prevents the persistence or recurrence of the toxic effects of organophosphate.

Adult↗
PubMed2003

Development and evaluation of an automated workstation for single nucleotide polymorphism discrimination using bacterial magnetic particles.

We designed an automated workstation for magnetic particle-based single nucleotide polymorphism (SNP) discrimination of ALDH genotypes. Bacterial magnetic particles (BMPs) extracted from Magnetospirillum magneticum AMB-1 were used as DNA carriers. The principle for SNP discrimination in this study was based on fluorescence resonance energy transfer (FRET) between FITC (donor) and POPO-3 (acceptor) bound to double-stranded DNA. The workstation is equipped with a 96-way automated pipetter which collects and dispenses fluids as it moves in x- and z-directions. The platform contains a disposable tip rack station, a reagent vessel serving as a stock for POPO-3 and FITC-labeled probes and a reaction station for a 96-well microtiter plate. BMPs were collected by attaching a neodymium iron boron sintered (Nd-Fe-B) magnet on the bottom of the microtiter plate. This system permits the simultaneous heating and magnetic separation of 96 samples per assay. The genotypes ALDH2*1 and ALDH2*2 were discriminated by calculating the relative fluorescence intensities on BMPs.

Aldehyde Dehydrogenase↗
PubMed2003

Single-nucleotide polymorphism analysis using fluorescence resonance energy transfer between DNA-labeling fluorophore, fluorescein isothiocyanate, and DNA intercalator, POPO-3, on bacterial magnetic particles.

To develop an analytical system for single-nucleotide polymorphisms (SNPs), the fluorescence resonance energy transfer (FRET) technique was employed on a bacterial magnetic particle (BMP) surface. A combination of fluorescein isothiocyanate (FITC; excitation 490 nm/emission 520 nm) labeled at the 5' end of DNA and an intercalating compound (POPO-3, excitation 534 nm/emission 570 nm) was used to avoid the interference from light scattering caused by nanoparticles. After hybridization between target DNA immobilized onto BMPs and FITC-labeled probes, fluorescence from POPO-3, which was excited by the energy from the FITC, was detected. The major homozygous (ALDH2*1), heterozygous (ALDH2*1/*2), and minor homozygous (ALDH2*2) genotypes in the blood samples were discriminated by this method. The assay described herein allows for a simple and rapid SNP analysis using a fully automated system.

Bacterial Proteins↗