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M Takayama

Publications and source records attributed to M Takayama.

At least 19 recordsLinked to original sources
PubMed2001

Avian-to-mammal transmission of an avian rotavirus: analysis of its pathogenicity in a heterologous mouse model.

It has been suggested that group A avian rotaviruses can be transmitted to mammals, but there is no direct evidence that such viruses induce disease in mammals. Suckling mice were orally inoculated with two avian rotaviruses. A pigeon rotavirus, PO-13, was found to induce diarrhea, but a turkey rotavirus, Ty-3, did not. The diarrhea induced by PO-13 was dependent on the age of the mouse. In histopathological examinations, antigens of PO-13 were sporadically detected in absorptive cells in the ileum, and lesions were observed as ballooning degenerations of absorptive cells in a region from the duodenum to the ileum. However, the rotavirus antigen was not detected in the majority of these degenerative cells. These results indicated that PO-13 could infect and induce diarrhea in suckling mice. This is the first evidence of an avian rotavirus being experimentally transmissible to a mammal.

Animals↗
PubMed2001

The correlation of TERT expression with c-myc expression in cervical cancer.

Recently putative catalytic telomerase subunit was identified as telomerase reverse transcriptase (TERT). Several reports showed that TERT expression correlated with telomerase activity. It has also been found that c-myc can induce telomerase activation through TERT expression. We examined expression of TERT and c-myc and their correlation in cervical cancers by reverse transcription-polymerase chain reaction (RT-PCR). It was found that TERT and c-myc expression was observed mostly in malignancies and expression of c-myc was concordant for positivity and negativity with TERT. These results support recent studies that c-myc expression is closely associated with TERT and telomerase activity. c-myc up-regulation may play an important role in activation of TERT and telomerase.

Cervix Uteri↗
PubMed2001

A novel amplification at 17q21-23 in ovarian cancer cell lines detected by comparative genomic hybridization.

OBJECTIVE: Little is known about the molecular mechanisms involved in the pathogenesis and/or progression of ovarian cancer (OC). To investigate the genomic imbalances and identify the cancer-related genes associated with this tumor, we applied comparative genomic hybridization (CGH) in OC cell lines. METHODS: Chromosomal aberrations among 17 OC cell lines were analyzed with CGH. Since novel chromosomal regions, including 17q21-23, were identified, we examined the involvement of two candidate genes, PS6K and ZNF147, mapped on this chromosomal region. We examined the status of amplification and expression by fluorescence in situ hybridization as well as by Southern blot analysis and by Northern blot analysis on two candidate genes, respectively. RESULTS: All lines displayed numerous chromosomal imbalances; the most frequent losses were observed on 18q22-23 (29.4%), 13q22-34 (23.5%), 9p (17.6%), 4p11-14 (17.6%), and 11p14-15 (17.6%). The most common gains were noted at 20q12-13 (47.1%), 8q23-24 (35.2%), 5p15 (23.5%), 7q32-36 (23.5%), and 20p (23.5%). High-level gains (HLGs) were detected at 20q12-13 (four cell lines), 8q24 (two cell lines), 12p11-12 (two cell lines), and 17q21-23 (two cell lines). PS6K and ZNF147 genes were amplified in two cell lines exhibiting HLGs at 17q21-23, but not overexpressed. CONCLUSIONS: Our CGH data indicate that OCs have various DNA copy number changes. Among these frequent changes, 17q21-23 may harbor another tumor-associated gene(s) responsible for OC carcinogenesis.

Chromosome Aberrations↗
PubMed2001

Human arylhydrocarbon receptor repressor (AHRR) gene: genomic structure and analysis of polymorphism in endometriosis.

The diversity of biological effects resulting from exposure to dioxin may reflect the ability of this environmental pollutant to alter gene expression by binding to the arylhydrocarbon receptor (AHR) gene and related genes. AHR function may be regulated by structural variations in AHR itself, in the AHR repressor (AHRR), in the AHR nuclear translocator (ARNT), or in AHR target molecules such as cytochrome P-4501A1 (CYP1A1) and glutathione S-transferase. Analysis of the genomic organization of AHRR revealed an open reading frame consisting of a 2094-bp mRNA encoded by ten exons. We found one novel polymorphism, a substitution of Ala by Pro at codon 185 (GCC to CCC), in exon 5 of the AHRR gene; among 108 healthy unrelated Japanese women, genotypes Ala/Ala, Ala/Pro, and Pro/Pro were represented, respectively, by 20 (18.5%), 49 (45.4%), and 39 (36.1%) individuals. We did not detect previously published polymorphisms of ARNT (D511N) or the CYP1A1 promoter (G-469A and C-459T) in our subjects, suggesting that these polymorphisms are rare in the Japanese population. No association was found between uterine endometriosis and any polymorphisms in the AHRR, AHR, ARNT, or CYP1A1 genes analyzed in the present study.

Aryl Hydrocarbon Receptor Nuclear Translocator↗
PubMed2001

Mother-to-infant transmission of TT virus in Japan.

OBJECTIVE: The TT virus (TTV) was detected for the first time by Nishizawa and Okamoto et al. in 1997 in the serum of a patient with post-transfusion hepatitis of unknown origin (non-A-non-G type). TTV was subsequently, also found in the serum of blood donors with no history of blood transfusion, although at a lower rate than among donors with a history of blood transfusion. In the present study, we determined the percentage of TTV carriers among pregnant women with no history of blood transfusion, and evaluated the possibility of mother-child transmission. METHODS: Blood was sampled from 300 normal pregnant women with no history of blood transfusion, 10 infants born by vaginal delivery from TTV-positive women, 10 infants born by abdominal cesarean section from TTV-positive women at both 5 days and 3 months after birth, and 10 infants born from TTV-positive women at 6 months after birth. Amniotic fluid and breast milk were sampled from 10 and 30 TTV-positive women, respectively. Informed consent was obtained from all women before sampling. TTV DNA was detected by the nested polymerase chain reaction (PCR) method. RESULTS: (1) Of the 300 normal pregnant women with no history of blood transfusion, 60 (20%) were TTV-positive. (2) All infants from TTV-positive mothers were TTV-negative at both 5 days and 3 months after birth, regardless of whether they were born by vaginal delivery or abdominal cesarean section. (3) Of the 10 infants who were born from TTV-positive mothers and examined 6 months after birth, 4 (40%) were TTV-positive. (4) Amniotic fluid from all 10 TTV-positive women was TTV-negative. (5) Breast milk from 7 (23.3%) of the 30 TTV-positive women was TTV-positive. CONCLUSION: TTV was detected in 20% of pregnant women with no history of blood transfusion, suggesting that TTV infection can occur through non- blood-mediated routes. The possibility of transfer of TTV into amniotic fluid was ruled out due to its absence in amniotic fluid samples. All infants from TTV-positive women were TTV-negative at both 5 days and 3 months after birth, regardless of whether they were born by vaginal delivery or abdominal cesarean section, suggesting that infection in the parturient canal or the pelvis is unlikely. Because TTV was detected in breast milk from TTV-positive women and some of their infants were TTV-positive, breast milk was thought to be a mother-child infection route. These findings suggest that horizontal infection is more likely than vertical infection in mother-child transmission of TTV.

Amniotic Fluid↗
PubMed2001

In-source decay characteristics of peptides in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

In-source decay (ISD) of peptides, coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, has been examined to determine the influence of the matrix, the susceptibility of amino-acid residues to ISD, and the effect of extraction delay times. Out of nine di- and tri-hydroxybenzoic acids and three cinnamic derivatives tested, the most suitable matrix for ISD was 2,5-dihydroxybenzoic acid. The amine bond at Xxx-Gly and Xxx-Val residues was less susceptible than other amino-acid residues to ISD; however, the more sensitive residue(s) were not as clear. Using a peptide that gave the y(n)- and (z(n) + 2)-series product ions, it was confirmed that amide-bond cleavage (formation of the y(n)-series ions) accompanied metastable peaks, whereas metastable peaks were never observed with amine-bond cleavage [formation of the (z(n) + 2)-series ions]. Furthermore, abundant c(n)-series ions, which originate from amine-bond cleavage on the peptide backbone, were observed whenever a minimum delay time of 38 ns or continuous extraction was used to obtain spectra. These data indicate that amine-bond cleavage in ISD takes place on the ionization time scale before the energy randomization is completed.

Adrenocorticotropic Hormone↗
PubMed2001

Serum insulin-like growth factor-1 in centenarians: implications of IGF-1 as a rapid turnover protein.

BACKGROUND: It is well documented that serum insulin-like growth factor 1 (IGF-1) levels as well as growth hormone secretion decline with advancing age. Low levels of IGF-1 are shown to be associated with low activity of growth hormone, low lean mass, and high body fat mass; however, in the elderly, the relationship has not been confirmed. METHODS: We studied serum IGF-1 levels in 49 centenarians, who are at the ultimate stage of physiological senescence, and investigated the possible relationship between IGF-1 and body mass index, lipid parameters, nutritional indices, physical and cognitive function, and frequency of hip fracture. As nutritional indices, serum levels of albumin, prealbumin, transferrin, and retinol binding protein were measured. Cognitive function of the centenarians was assessed by clinical dementia rating. RESULTS: In the centenarians, the mean levels of IGF-1 were relatively low, indicating that there is an age-associated decline in IGF-1 even in the extremely old age. We demonstrated a strong association of IGF-1 with prealbumin and retinol binding protein (r2 = .192, .195, respectively); however, there was no association with albumin, transferrin, or body mass index. Interestingly, centenarians with lower IGF-1 levels had a higher prevalence of definitive dementia. CONCLUSIONS: These data suggest that serum IGF-1 levels in the centenarians appeared to reflect their short-term nutritional status as a rapid turnover protein. It is also suggested that low levels of serum IGF-1 may be involved in the progression of dementia in the oldest old.

Aged↗
PubMed2001

Herpes simplex mimicking herpes zoster in a child immunized with varicella vaccine.

A 5-year-old boy had zosteriform vesicular lesions 4 years after immunization with varicella vaccine. PCR analyses of DNA extracted from the crusts revealed herpes simplex virus type 1 infection. Virologic examinations should be performed before the vesicular lesion is attributed to the varicella-zoster virus vaccine strain.

Chickenpox Vaccine↗
PubMed2001

Rescue of rabies virus from cloned cDNA and identification of the pathogenicity-related gene: glycoprotein gene is associated with virulence for adult mice.

In order to identify the viral gene related to the pathogenicity of rabies virus, we tried to establish a reverse genetics system of the attenuated RC-HL strain, which causes nonlethal infection in adult mice after intracerebral inoculation. A full-length genome plasmid encoding the complete antigenomic cDNA of the RC-HL strain and helper plasmids containing cDNAs of the complete open reading frame of the N, P, and L genes, respectively, were constructed. After transfection of these plasmids into BHK-21 cells infected with the T7 RNA polymerase-expressing vaccinia virus, infectious rabies virus with almost the same biological properties as those of the wild-type RC-HL strain was rescued. Using this reverse genetics system of the RC-HL strain, we generated a chimeric virus with the open reading frame of the glycoprotein gene from the parent Nishigahara strain, which kills adult mice after intracerebral inoculation, in the background of the RC-HL genome. Since the chimeric virus killed adult mice following intracerebral inoculation, it became evident that the open reading frame of the glycoprotein gene is related to the pathogenicity of the Nishigahara strain for adult mice.

Animals↗
PubMed2001

Effects of neutrophil elastase inhibitor (ONO-5046) on lung injury after intestinal ischemia-reperfusion.

The underlying mechanisms of lung endothelial injury after intestinal ischemia-reperfusion (I/R) injury are not fully known. Here we investigated the effects of posttreatment with a neutrophil elastase inhibitor (NEI; ONO-5046) on lung injury after intestinal I/R injury in a rat model. Intestinal I/R was produced by 90 min of ischemia followed by either 60 or 240 min of reperfusion. For all experimental groups, the endothelial permeability index increased, neutrophil H(2)O(2) production increased in the pulmonary vasculature blood, neutrophil counts increased in bronchoalveolar lavage fluid (BALF), and the cytokine-induced neutrophil chemoattractant (CINC)-1 and CINC-3 levels were increased in BALF after 240 min (P < 0.01). In rats treated with NEI from 60 min after reperfusion, the lung endothelial permeability index was significantly reduced (P < 0.05), whereas neutrophil H(2)O(2) production in pulmonary vasculature blood and neutrophil count in BALF were significantly suppressed by NEI (P < 0.05 and P < 0.01, respectively). In addition, NEI significantly suppressed the increase of CINC-1 and CINC-3 levels in BALF (P < 0.05). Our study clearly indicates that posttreatment with NEI reduces neutrophil activation in the pulmonary vessels and neutrophil accumulation in the lungs and suggests that ONO-5046, even when administered after the primary intestinal insult, can prevent the progression of lung injury associated with intestinal I/R.

Animals↗
PubMed2001

Characterization of PBZ1, a probenazole-inducible gene, in suspension-cultured rice cells.

Probenazole (PBZ) induces non-race specific resistance in rice plants against rice blast fungus and PBZ1 was identified as a PBZ-inducible gene from rice. The induction of PBZ1 expression in suspension-cultured rice cells was investigated. Northern blot analysis indicated that PBZ1 was induced by PBZ in a dose-dependent manner. Enzyme-linked immunosorbent assay (ELISA) showed a dose and time-dependent accumulation of PBZ1 protein. Both mRNA and protein analysis showed that PBZ1 was not induced by salicylic acid or an active metabolite, 1,2-benzisothiazole-1,1-dioxide.

Cell Line↗
PubMed2001

The adaptive bleaching hypothesis: experimental tests of critical assumptions.

Coral bleaching, the loss of color due to loss of symbiotic zooxanthellae or their pigment, appears to be increasing in intensity and geographic extent, perhaps related to increasing sea surface temperatures. The adaptive bleaching hypothesis (ABH) posits that when environmental circumstances change, the loss of one or more kinds of zooxanthellae is rapidly, sometimes unnoticeably, followed by formation of a new symbiotic consortium with different zooxanthellae that are more suited to the new conditions in the host's habitat. Fundamental assumptions of the ABH include (1) different types of zooxanthellae respond differently to environmental conditions, specifically temperature, and (2) bleached adults can secondarily acquire zooxanthellae from the environment. We present simple tests of these assumptions and show that (1) genetically different strains of zooxanthellae exhibit different responses to elevated temperature, (2) bleached adult hosts can acquire algal symbionts with an apparently dose-dependent relationship between the concentration of zooxanthellae and the rate of establishment of the symbiosis, (3) and finally, bleached adult hosts can acquire symbionts from the water column.

Adaptation, Physiological↗
PubMed2001

[Suggestions from a centenarian study--aging and inflammation].

With the numbers of elderly increasing rapidly, it is important for both individuals and society that the oldest old maintains autonomy. To know how to attain successful aging, we investigate the status of centenarians. The characteristics of centenarians in Tokyo is 1) low level of nutritional parameters, 2) low level of cholesterol and HDL-cholesterol, 3) low level of red blood cells and hemoglobin, 4) high level of CRP, 5) high level of homocysteine, 6) high level of von Willbrand factor. The incidence of dementia is 59.3%. Are these characteristics due to aging itself or other factors? We examined the effect of nutritional status, inflammation and level of homocysteine on the characteristics. The level of albumin is associated with serum level of lipid, RBC, ADL and cognitive function. The level of CRP is related to the level of albumin, suggesting that inflammation is related to nutritional status. The level of homocysteine is associated with the level of von Willbrand factor, suggesting that homocysteine is related to endothelial injury. From these data, we propose the hypothesis that proinflammatory status is associated with aging, resulting in a part of characteristics of centenarians. Homocysteine is partly responsible for endothelial injury. Intervention to suppress proinflammatory status and homocysteine level may promote QOL in the oldest old.

Aged↗
PubMed2000

CDC6 interacts with c-Myc to inhibit E-box-dependent transcription by abrogating c-Myc/Max complex.

The c-myc oncogene product (c-Myc) is a transcription factor that dimerizes with Max and recognizes the E-box sequence. It plays key functions in cell proliferation, differentiation and apoptosis. It is generally thought that c-Myc transactivates genes encoding proteins essential to cell-cycle progression by binding to the E-boxes that control them. The functions of c-Myc are also thought to be modulated by its associated proteins, several of which have recently been identified. In this study, we found that c-Myc directly bound in vivo and in vitro to the N-terminal region of human CDC6, a component of the pre-replication complex, and that both co-localized in cell nuclei. CDC6 bound to the C-proximal region of c-Myc, thereby competing with Max on the E-box sequence and changing c-Myc/Max heterodimer to a Max/Max homodimer. In consequence, the E-box-dependent transcription activity of c-Myc was abrogated. These results suggest that, in addition to its DNA replication activity, CDC6 also has a role as a transcriptional suppressor of c-Myc.

Basic Helix-Loop-Helix Leucine Zipper Transcriptio↗
PubMed2000

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using an inorganic particle matrix for small molecule analysis

Fine metal or metal oxide powder as an alternative to conventional organic matrices in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) has been utilized successfully for lower molecular mass analytes, poly(ethylene glycol) 200 (PEG 200) and methyl stearate. Eleven kinds of particle, Al, Mn, Mo, Si, Sn, SnO2, TiO2, W, WO3, Zn and ZnO, were evaluated. The analyte was mixed with a metal or metal oxide powder (inorganic matrix) with particle diameter of tens of micrometers and liquid dispersant, followed by application to the sample target. Using a commercial MALDI-TOFMS instrument equipped with an internal 337 nm pulsed nitrogen laser, the analytes, PEG 200 and methyl stearate, were ionized as the alkali metal ion adducted molecules [M+Na]+ or [M+K]+ when the inorganic matrices Mn, Mo, Si, Sn, TiO2, W, WO3, Zn or ZnO were used. In the case of an Al matrix, PEG 200 was ionized as [M+K]+, whereas methyl stearate was ionized as [M+H]+ and [M+Al]+. These particles have potential as the matrix for MALDI. During our examination, however, only SnO2 particles did not ionize either PEG 200 or methyl stearate. Based on our protocol, when TiO2 powder was suspended with liquid paraffin, PEG 200 and methyl stearate gave their MALDI-TOF mass spectra with the lowest background noise and highest intensity. TiO2 powder seemed to be a broad potential matrix for low molecular mass polar or non-polar analytes. The results suggested that bulk particles caused rapid heating/vaporization processes and ionized analyte molecules under irradiation with a pulsed UV laser. The present method can be readily applied to obtain the low background noise MALDI-TOF mass spectra of small-sized compounds.

Journal Article↗
PubMed2000

Sequence information of peptides and proteins with in-source decay in matrix assisted laser desorption/ionization-time of flight-mass spectrometry.

In-source decay coupled with matrix assisted laser desorption/ionization-mass spectrometry, which is a mass spectrometric degradation method for the sequencing of peptides and proteins, has been applied to several different polypeptides and proteins. The influence of the nature of the constituent amino acids on positively charged product ions is described. Relatively small molecular mass peptides produced c-, b-, and/or a-series ions usable for C-terminal sequencing as well as y- and/or z-series ions usable for N-terminal sequencing. The formation of the C-terminal sequencing ions (c, b and a) and the N-terminal sequencing ions (y and z) was strongly dependent on the location(s) of basic arginine and lysine residues. The presence of the arginine and/or lysine residues at the N-terminal region was one-sided in the formation of c-, b-, and/or a-series ions, while the presence of those at the C-terminal region was favorable for the formation of y- and z-series ions. In-source decay experiments of intact proteins, apomyoglobin and two viral coat proteins, led to large amounts of c-series ions and small amounts of y-series ions, which reflected internal sequences.

Amino Acid Sequence↗
PubMed2000

Study on fragmentation behavior of 5/7/6-type taxoids by tandem mass spectrometry.

The mass spectrometric behaviors of seven compounds, namely four 4beta(20),5-oxetane 5/7/6-type taxoids (i.e. taxayuntin A, taxayuntin B, taxayuntin and taxayuntin C) and three 4(20)-methylene 5/7/6-type taxoids (i.e. brevifoliol, taxchinin A and 7-acetyl-10-deacetyl-7-debenzoylbrevifoliol) have been investigated by the positive ion FAB-MS/MS technique. The fragmentation has been correlated with the types and positions of substituents of these compounds. It has been found that with the OH group at the C-10 position, taxayuntin A, taxayuntin B and 7-acetyl-10-deacetyl-7-debenzoylbrevifoliol are dominated by the loss of H2O, while with the BzO group at the C-10 position, taxayuntin, taxayuntin C, brevifoliol and taxchinin A preferentially eliminate the BzO group. In addition, C-2 is an active site, and neutral loss from the C-2 position readily occurs. The four 4beta(20),5-oxetane 5/7/6-type taxoids produce the terminal product ion with a stable conjugated system at m/z 311, while the 4(20)-methylene 5/7/6-type taxoids brevifoliol and 7-acetyl-10-deacetyl-7-debenzoylbrevifoliol produce this ion at m/z 237, and taxchinin A at m/z 253. Interestingly, characteristic fragment ions involving the loss of a 118 u group were observed for taxayuntin, and a possible fragmentation mechanism is given. The major fragmentation pathways and mechanisms of ion formation for the compounds are proposed on the basis of CID spectra and accurate mass measurements. The results of this paper will be helpful for structural analysis of analogs.

Plant Extracts↗