Search PubMed⌕ Search

Biomedical subjects

R Takahashi

Publications and source records attributed to R Takahashi.

At least 19 recordsLinked to original sources
PubMed2006

Immunohistochemical analysis of nuclear survivin expression in esophageal squamous cell carcinoma.

Despite advances in the treatment of esophageal carcinoma, the prognosis for this disease remains poor. Therefore, it is important to obtain a better understanding of the molecular basis of esophageal carcinogenesis. The purpose of this study was to clarify the roles of survivin in esophageal squamous cell carcinoma (ESCC). One hundred 22 ESCC surgical specimens resected from 1989 to 1999 were examined. Survivin expression was assessed by immunohistochemistry. Tumor cells were considered survivin-positive if the immunoreactivity was confined to the nucleus, and a scoring method was applied. Survivin-positive immunostaining was detected in 68 patients (56%). There was a significant association between survivin expression and pN (P = 0.0472). Moreover, the overall survival rate was worse in patients with survivin-positive tumors than in patients with survivin-negative tumors (P = 0.0189). The overexpression of survivin was associated with the overall survival rate and poor prognosis in patients with ESCC. Survivin may be targeted during cancer therapy because of its selective expression in malignant tissue.

Aged↗
PubMed2005

Lowest limit for detection of impurity concentration in semiconductors by fluorescence XAFS: resonant Raman scattering and angle dependence.

The lowest limit for detection (LLD) of the impurity concentration doped in semiconductors in the case of fluorescence XAFS measurements has been investigated as a function of the matrix of the impurity and the geometry of the measurement. When the impurity concentration is very low and other background noise is well suppressed, X-ray resonant Raman scattering by the constituent atoms of the matrix remains as a major background for the fluorescence-detected XAFS measurement. For example, in the fluorescence-detected XAFS measurement for Er-doped semiconductors at the Er L(III)-edge, the LLD of the Er concentration was about 5 x 10(14) to 1 x 10(15) cm(-2) for GaAs and GaP, and lower than 1 x 10(14) cm(-2) for InP. The resonant Raman scattering of Ga atoms in the host semiconductor determines the LLD.

Erbium↗
PubMed2005

Molecular linkage mapping and phylogeny of the chalcone synthase multigene family in soybean.

Chalcone synthase (CHS), the key enzyme in the flavonoid biosynthesis pathway, is encoded by a multigene family, CHS1-CHS8 and dCHS1 in soybean. A tandem repeat of CHS1, CHS3 and CHS4, and dCHS1 that is believed to be located in the vicinity comprises the I locus that suppresses coloration of the seed coat. This study was conducted to determine the location of all CHS members by using PCR-based DNA markers. Primers were constructed based on varietal differences in either the nucleotide sequence of the 5'-upstream region or the first intron of two cultivars, Misuzudaizu, with a yellow seed coat (II), and Moshidou Gong 503, with a brown seed coat (ii). One hundred and fifty recombinant inbred lines that originated from a cross between these two cultivars were used for linkage mapping together with 360 markers. Linkage mapping confirmed that CHS1, CHS3, CHS4, dCHS1, and the I locus are located at the same position in molecular linkage group (MLG) A2. CHS5 was mapped at a distance of 0.3 cM from the gene cluster. CHS2 and CHS6 were located in the middle region of MLGs A1 and K, respectively, while CHS7 and CHS8 were found at the distal end of MLGs D1a and B1, respectively. Phylogenetic analysis indicated that CHS1, CHS3, CHS4, and CHS5 are closely related, suggesting that gene duplication may have occurred repeatedly to form the I locus. In addition, CHS7 and CHS8 located at the distal end and CHS2, CHS6, and CHS members around the I locus located around the middle of the MLG are also related. Ancient tetraploidization and repeated duplication may be responsible for the evolution of the complex genetic loci of the CHS multigene family in soybean.

Acyltransferases↗
PubMed2005

Cyclin D1, E2F1 expression levels are associated with characteristics and prognosis of esophageal squamous cell carcinoma.

SUMMARY. We performed a multi-institutional analysis of E2F1 and cyclin D1 expression in cases of esophageal squamous cell carcinoma (ESCC). Cyclin D1 and E2F1 are involved in the transition of cell cycle phases and associated with tumor progression. However, no previous studies have concurrently analyzed combined E2F1 and cyclin D1 expression. The purpose of this study was to clarify the relationship of E2F1 and cyclin D1 in ESCC. We studied 122 patients with primary ESCC who underwent surgical tumor resection. Immunohistochemical analyses were performed for E2F1 and cyclin D1. A statistical analysis of immunohistochemistry results, clinicopathological features, and prognosis was performed. E2F1/cyclin D1 (-/-) tumors were present in 31 patients (25.4%) and correlated with reduced tumor progression. In these patients, pT (P=0.0001), pN (P<0.0001), p-Stage (P=0.0019), and survival rates were better than in patients who were positive for either E2F1 or cyclin D1 (P=0.0232). The expression of E2F1 and cyclin D1 is an indicator of tumor progression and prognosis in patients with ESCC. Combined analysis of E2F1 and cyclin D1 expression helps to determine the characteristics and prognosis of ESCC.

Adult↗
PubMed2005

Association of mannose binding lectin (MBL) gene polymorphism and serum MBL concentration with characteristics and progression of systemic lupus erythematosus.

OBJECTIVE: To determine whether occurrence, characteristics, and progression of systemic lupus erythematosus (SLE) are associated with polymorphism of the mannose binding lectin (MBL) gene and with serum MBL concentration. METHODS: Codon 54 MBL gene polymorphism of 147 patients with SLE and 160 healthy controls was determined by polymerase chain reaction-restriction fragment length polymorphism. Serum concentration of MBL was measured by enzyme immunoassay. Fluctuations of serum MBL were analysed with respect to disease characteristics and activity. RESULTS: Frequency of homozygosity for codon 54 minority allele was 6% (9/147) in patients with SLE, and significantly higher than in controls (p = 0.0294, Fisher's exact test). MBL polymorphism in patients with SLE was not significantly associated with disease characteristics or immunological phenotypes. Patients homozygous for the B allele tended to have a higher risk of infection during treatment. Levels of C3 and CH(50) were slightly, but significantly, associated with serum MBL concentration in patients with SLE homozygous for the majority allele. During the course of SLE, serum MBL concentration increased in 6/14 patients, and decreased in 7 after initiation of immunosuppressive treatment. CONCLUSIONS: MBL gene polymorphism influences susceptibility to SLE, but has no direct effect on disease characteristics. Serum MBL levels fluctuate during the course of SLE in individual patients. MBL genotyping may be useful in assessing the risk of infection during treatment of SLE.

Adolescent↗
PubMed2004

Mitochondrial protease Omi/HtrA2 enhances caspase activation through multiple pathways.

Omi/HtrA2 is a mitochondrial serine protease that is released into the cytosol during apoptosis and promotes cytochrome c (Cyt c)dependent caspase activation by neutralizing inhibitor of apoptosis proteins (IAPs) via its IAP-binding motif. The protease activity of Omi/HtrA2 also contributes to the progression of both apoptosis and caspase-independent cell death. In this study, we found that wild-type Omi/HtrA2 is more effective at caspase activation than a catalytically inactive mutant of Omi/HtrA2 in response to apoptotic stimuli, such as UV irradiation or tumor necrosis factor. Although similar levels of Omi/HtrA2 expression, XIAP-binding activity, and Omi/HtrA2 mitochondrial release were observed among cells transfected with catalytically inactive and wild-type Omi/HtrA2 protein, XIAP protein expression after UV irradiation was significantly reduced in cells transfected with wild-type Omi/HtrA2. Recombinant Omi/HtrA2 was observed to catalytically cleave IAPs and to inactivate XIAP in vitro, suggesting that the protease activity of Omi/HtrA2 might be responsible for its IAP-inhibiting activity. Extramitochondrial expression of Omi/HtrA2 indirectly induced permeabilization of the outer mitochondrial membrane and subsequent Cyt c-dependent caspase activation in HeLa cells. These results indicate that protease activity of Omi/HtrA2 promotes caspase activation through multiple pathways.

Apoptosis↗
PubMed2004

Anti-mannose binding lectin antibodies in sera of Japanese patients with systemic lupus erythematosus.

Mannose-binding lectin (MBL) is a key element in innate immunity with functions and structure similar to that of complement C1q. It has been reported that MBL deficiency is associated with occurrence of systemic lupus erythematosus (SLE). We hypothesized that anti-MBL antibodies, if present, would affect the occurrence or disease course of SLE, by reduction of serum MBL levels, interference of MBL functions, or binding to MBL deposited on various tissues. To address this hypothesis, we measured the concentration of anti-MBL antibodies in sera of 111 Japanese SLE patients and 113 healthy volunteers by enzyme immunoassay. The titres of anti-MBL antibodies in SLE patients were significantly higher than those in healthy controls. When the mean + 2 standard deviations of controls was set as the cut off point, individuals with titres of anti-MBL antibodies above this level were significantly more frequent in SLE patients (9 patients) than in controls (2 persons). One SLE patient had an extremely high titre of this antibody. No associations of titres of anti-MBL antibodies and (i) genotypes of MBL gene, (ii) concentrations of serum MBL, or (iii) disease characteristics of SLE, were apparent. Thus, we have confirmed that anti-MBL antibodies are indeed present in sera of some patients with SLE, but the significance of these autoantibodies in the pathogenesis of SLE remains unclear.

Autoantibodies↗
PubMed2004

Structural analysis of a new anti-hypertensive peptide (beta-lactosin B) isolated from a commercial whey product.

Angiotensin-converting enzyme (ACE) inhibitory activities and anti-hypertensive activities in spontaneously hypertensive rats (SHR) of 12 kinds of commercial peptides of food additive grade were measured. Four peptide products derived from milk proteins showed strong anti-hypertensive activities (>-18.0 mm Hg). A sample of WE80BG derived from whey proteins showed the strongest anti-hypertensive activity (-21.2 +/- 16.9 mm Hg) with a medium level of ACE inhibitory activity (53.6%), and it was subjected to hydrophobic and gel filtration chromatography. From the low molecular weight fraction, an anti-hypertensive peptide was isolated by using reversed-phase HPLC, and it was found to be a tetrapeptide, alanine-leucine-proline-methionine (Ala-Leu-Pro-Met, ALPM), the origin of which was estimated to be beta-lactoglobulin f 142 to 145. At 8 h after oral administration of ALPM in SHR, systolic blood pressure was significantly decreased (-21.4 +/- 7.8 mm Hg), but the IC50 value (concentration of peptide needed to inhibit 50% of the ACE activity) of ALPM was not so high. We named the Ala-Leu-Pro-Met "beta-lactosin B." This peptide is the second anti-hypertensive peptide found from beta-lactoglobulin. Because WE80BG containing ALPM was also found to show the strongest anti-hypertensive activity (-24.5 +/- 10 mm Hg) at 8 h after oral administration in SHR, WE80BG would be suitable for application to the development of a new food expected to have anti-hypertensive effects.

Amino Acids↗
PubMed2003

Medical assistance at the Brazilian juniors tennis circuit--a one-year prospective study.

A prospective study was conducted during one year to evaluate injuries in Brazilian Junior tennis players during the national circuit, in 2001. Male and female athletes in the age categories under 12, under 14, under 16 and under 18 years, all members of The Brazilian Tennis Confederation, participated in the study. Two physiotherapists and/or one physician evaluated the athletes. A total of 280 medical examinations were performed in 151 tennis players who needed medical treatment during the tournaments. The 151 athletes had 1-6 medical treatments during the tournaments and the mean was 1.8 treatment per athlete. The overall incidence was 6.9 medical treatments for every 1,000 games played. Medical assistance tothe athletes was performed on court in 83 (29.6%) occasions, 185 (66.1%) at the medical department and in both in 12 (4.3%) occasions. Retirement of the match was reported in 9 (3.2%) lesions. The most frequent injuries were: muscle contractures (76 - 27.14%), muscle pain/fatigue (36-12.85%), muscle strain (35-12.52%), tendinopathies (20 - 7.14%), cramps (16 -5.71%), ankle sprain (12 -4.28%) and low back pain (10-3.57%). Muscle pathology was the major source of injuries causing the athlete to seek medical assistance. Preventative measures are important to reduce the number of injuries, which may include muscle stretching programs and adequate nutrition and hydration.

Adolescent↗
PubMed2003

Acute effects of ethanol on feeding behavior and leptin-induced STAT3 phosphorylation in rat hypothalamus.

OBJECTIVE: Drinking ethanol stimulates the appetite, producing a positive energy balance. The mechanism by which ethanol regulates the appetite in the central nervous system, however, has not been fully understood. The aim of this study is to investigate the interaction of ethanol with the satiety effect of leptin, a hormone which suppresses the appetite in the hypothalamic region. DESIGN: : Leptin (7.5 micro g) or the same dose of phosphate buffer saline (PBS) was administered into the third ventricle (i.c.v.), 30 min after an intraperitoneal injection (i.p.) of ethanol (0.5 g/kg body weight) or the same dose of PBS. MATERIALS: Adult male Sprague-Dawley rats weighing 290-320 g were used. MEASUREMENTS: Food intake was measured 2, 12 and 24 h after leptin i.c.v. infusion. The tyrosine phosphorylation of signal transducer and activator transcription factor 3 (STAT3) in the hypothalamus was analyzed by Western blotting. RESULTS: The cumulative food intakes in the saline/leptin group (saline i.p.+leptin i.c.v.) were markedly reduced to about 45% of the saline/PBS group (saline i.p.+PBS i.c.v.) at 2, 12 and 24 h time points (P<0.05, 0.001, and 0.005, respectively). As compared with the saline/leptin group, those of the ethanol/leptin group (ethanol i.p.+leptin i.c.v.) were significantly increased to the level seen in the saline/PBS group at 12 and 24 h time points (P<0.05, and P<0.005 vs the saline/leptin group, respectively). Ethanol administration resulted in about a 50% reduction of the leptin-induced STAT3 tyrosine phosphorylation seen in the hypothalamic protein as compared to that of the saline/leptin group. CONCLUSION: These findings suggest that ethanol-induced enhancement of the appetite may, in part, result from leptin resistance transiently caused by ethanol to attenuate the leptin signal transduction.

Animals↗
PubMed2003

Increased circulating interleukin-12 (IL-12) p40 in pulmonary sarcoidosis.

In sarcoidosis, a T helper 1 (Th1) response is an essential event and the up-regulation of interleukin-12 (IL-12) has been detected in affected disease sites. In order to investigate the clinical usefulness of circulating IL-12, we measured the serum concentrations of IL-12 by ELISA and performed immunohistochemistry using specific MoAbs for IL-12 in the lungs and scalene lymph nodes of patients with sarcoidosis. The serum concentration of IL-12 p40 was detectable in all 45 patients with pulmonary sarcoidosis and 18 normal controls, whereas that of IL-12 p70 was undetectable. The serum concentrations of IL-12 p40 in pulmonary sarcoidosis were significantly higher than those of the normal controls, especially in cases with abnormal intrathoracic findings detected by chest roentogenogram. The serum concentrations of interferon-gamma (IFN-gamma) also increased compared with those of normal controls and there was a significant positive correlation between the serum concentrations of IL-12 p40 and IFN-gamma. Furthermore, serum angiotensin-converting enzyme (ACE) and lysozyme, which are known to be useful markers for disease activity in sarcoidosis, correlated well with the serum concentrations of IL-12 p40. The positive 67Ga scan group (for lung field) had significantly elevated serum IL-12 p40 levels compared with those of the negative group. No bioactivity of IL-12 p70 was detected in three sarcoid cases sera by using the IL-12 responsive cell line. Finally, the immunohistochemical approach revealed that IL-12 p40 was expressed in the epithelioid cells and macrophages of sarcoid lungs and lymph nodes. We concluded that the production of IL-12 p40 was far greater in the sera and we have demonstrated this to be a useful clinical marker for disease activity and the Th1 response in pulmonary sarcoidosis.

Analysis of Variance↗
PubMed2003

A clinical follow up of PRK and LASIK in eyes with preoperative abnormal corneal topographies.

AIM: To assess the safety and predictability of photorefractive keratotomy (PRK) and laser in situ keratomileusis (LASIK) based on preoperative corneal topography. METHODS: A non-randomised comparative study was carried out on 84 eyes that presented with topographic abnormalities before undergoing PRK (n = 44) or LASIK (n = 40) procedures. 84 spherical equivalent paired normal eyes served as the control group. Either PRK or LASIK procedures were performed on 168 eyes using the Summit apex plus excimer laser. Topographic abnormalities, including apex displacement (AD), increased asphericity (AS), meridional irregularity (MI), increased inferior-superior asymmetry (IS), increased curvature (CU), and combined features (CO), were assessed preoperatively using the EyeSys analysis system. Safety and predictability of the two procedures were defined as a postoperative visual acuity of 20/40 or better and the loss of one or more lines of spectacle corrected visual acuity (SCVA). RESULTS: All patients were followed for 6 months. There was a significant loss of best corrected visual acuity in the PRK-AD (p<0.001), PRK-CO (p<0.05), and LASIK-AS (p<0.001) patients. The number of eyes within plus or minus 1.0D of the surgical plan postoperatively was similar in all groups. CONCLUSION: These data suggest that although predictability was similar, PRK and LASIK performed in corneas with topographic abnormalities might cause loss of vision.

Corneal Diseases↗
PubMed2002

Yeast two-hybrid screening using constitutive-active caspase-7 as bait in the identification of PA28gamma as an effector caspase substrate.

Caspase-3 and -7 represent executioner/effector caspases that directly cause apoptotic morphological changes by cleaving various death substrates. The substrates for caspases generally interact with active caspases, but not with inactive zymogens of caspase or procaspases. Here, to isolate proteins that interact with caspase-7, we established a yeast two-hybrid screening system using reversed-caspase-7, a constitutive active mutant of caspase-7 as a bait plasmid. Screening of an adult brain cDNA library led to isolation of proteasome activator 28 subunit, PA28gamma. In vitro translates of PA28gamma were cleaved by both recombinant caspase-3 and -7. Mutagenesis of potential cleavage site DGLD80 to EGLE80 completely abolished caspase-mediated cleavage. Moreover, endogenous PA28gamma was cleaved during not only Fas-induced apoptosis of HeLa cells, but also cisplatin-induced cell death of MCF7 cells, which are devoid of caspase-3. These findings indicate that PA28gamma is an endogenous substrate for caspase-3 and -7 and that yeast two-hybrid screening using reversed-caspase is a novel and useful approach to clone substrates for effector caspases.

Apoptosis↗
PubMed2002

Lactobacillus casei strain Shirota suppresses serum immunoglobulin E and immunoglobulin G1 responses and systemic anaphylaxis in a food allergy model.

BACKGROUND: Our previous study using allergen-sensitized murine splenocyte cultures has shown that Lactobacillus casei strain Shirota (LcS), a lactic acid bacterium widely used as a starter for fermented milk products, suppresses IgE production through promoting a dominant Th1-type response mediated by IL-12 induction. OBJECTIVE: We tried to evaluate the ability of LcS to suppress both IgE response and allergic reactions in vivo using a food allergy model with ovalbumin-specific T cell receptor transgenic (OVA-TCR-Tg) mice. METHODS: The ability of heat-killed LcS to induce IL-12 in serum was tested. OVA-TCR-Tg mice were fed a diet containing OVA for 4 weeks and injected with LcS intraperitoneally three times in the first week of this period. Cytokine and antibody secretion by splenocytes, and serum IgE and IgG1 responses were examined. The inhibitory effect of LcS on systemic anaphylaxis induced by intravenous challenge of OVA-fed OVA-TCR-Tg mice with OVA was also tested. RESULTS: Intraperitoneal injection of LcS induced an IL-12 response in the serum of OVA-TCR-Tg mice. In the food allergy model, LcS administration skewed the pattern of cytokine production by splenocytes toward Th1 dominance, and suppressed IgE and IgG1 secretion by splenocytes. The ability of LcS to modulate cytokine production was blocked by anti-IL-12 antibody treatment. LcS also inhibited serum OVA-specific IgE and IgG1 responses and diminished systemic anaphylaxis. CONCLUSION: LcS administration suppresses IgE and IgG1 responses and systemic allergic reactions in a food allergy model, suggesting a possible use of this lactic acid bacterium in preventing food allergy.

Anaphylaxis↗
PubMed2002

Effect of formaldehyde on the expression of adhesion molecules in nasal microvascular endothelial cells: the role of formaldehyde in the pathogenesis of sick building syndrome.

BACKGROUND: Formaldehyde is associated with sick building syndrome (SBS), a set of diffuse and irritative symptoms predominantly involving the eyes and the respiratory tract. However, its pathophysiological mechanism in SBS has not yet been clarified. OBJECTIVE: In this study we investigated the effect of formaldehyde on the expression of adhesion molecules on human mucosal microvascular endothelial cells (HMMECs). Furthermore, we investigated the effect of formaldehyde on adhesiveness of HMMECs to eosinophils. MATERIALS AND METHODS: HMMECs were incubated with various concentrations of formaldehyde (1 ng/mL-1 microg/mL) for 24 h, and the expressions of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM-1) on HMMECs were evaluated by flow cytometry. The change in the expression of ICAM-1 and VCAM-1 mRNA was then evaluated by reverse transcriptase polymerase chain reaction. To understand the role of formaldehyde in eosinophilic inflammation of the nasal mucosa, we examined the effects of formaldehyde on the adhesiveness between HMMECs and eosinophils by eosinophil adhesion assay. RESULTS: Formaldehyde increased the surface expressions of ICAM-1 and VCAM-1 on HMMECs. Formaldehyde also induced ICAM-1 and VCAM-1 mRNA. In addition, the adhesiveness between HMMECs and eosinophils was also increased by formaldehyde. CONCLUSION: These in vitro studies suggest that formaldehyde may play a role as the irritant of the nasal mucosa by increasing the expressions of adhesion molecules on HMMECs and by enhancing the adhesiveness between HMMECs and eosinophils.

Cell Adhesion↗
PubMed2002

Runoff characteristics of nutrients from citrus fruit grove and its effects on water area.

In this study, field observations are carried out in order to make clear the runoff characteristics of pollutants from citrus fruit grove, especially nutrients such as nitrogen, phosphorus and other inorganic materials. Long-term observation in the test fields continued for more than 7 months and detailed observations during one rainfall are also carried out. From these observations, the following results are obtained. 1) Nitrogen concentration in grove soil leachate is usually in a range of 25 to 45 mgN/L, and the main component is nitrate, whereas phosphorus concentration is in a range of 0.1 to 0.8 mgP/L and the main component is phosphate. Concentration of nutrients is higher than that in environment around it. 2) Runoff loading rate of any materials from grove soil can be unified and expressed as a power function of the flow rate. In this case, runoff style of each material is characterized by the power coefficient beta x. 3) It is understood that the runoff characteristics are affected by the pH and rate of rainfall, and the ways of affecting the runoff characteristics are different in each material. 4) It is also suggested that detailed investigations are required to estimate the effect of pollutant runoff because the runoff characteristics are widely changed by the rainfall characteristics.

Agriculture↗
PubMed2002

Comparison of dry ice-baited centers for disease control and New Jersey light traps for measuring mosquito abundance in California.

Mosquito catch in New Jersy light traps (NJLTs) has been declining in recent years, compromising the sensitivity of the California mosquito monitoring program. Centers for Disease Control traps (CDCTs) operated without light and augmented with dry ice have been considered for replacement or augmentation. To provide information on comparative sensitivity and ability to measure abundance over time and space, catch of mosquitoes in NJLTs was compared to catch in CDCTs operated concurrently at 8-10 sites within the Coachella Valley, Kern, San Joaquin County, and Sacramento-Yolo Mosquito and Vector Control Districts. The CDCTs always collected more female mosquitoes than did NJLTs; however, differences in sensitivity varied markedly over time and space precluding the calculation of a universal conversion factor. Regressions of the catch of female Culex tarsalis in CDCTs as a function of catch in NJLTs within districts indicated that the slopes varied markedly, again precluding the derivation of a universal function. Therefore, we recommend that mosquito surveillance programs replace or supplement NJLTs with systematically operated CDCTs to enhance sampling sensitivity for females of most mosquito species. However, both trap types should be operated concurrently at several sites within each district to derive regression functions to convert historical relative abundance data from NJLTs to equivalent counts in CDCTs for retrospective analyses.

Aedes↗