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T Takeda

Publications and source records attributed to T Takeda.

At least 19 recordsLinked to original sources
PubMed2006

Different real-time PCR assays could lead to a different result of detection of varicella-zoster virus in facial palsy.

Real-time PCR is a useful tool for rapid detection of viral genomic DNA. However, there are many types of real-time PCR, and this variation may induce different results. The sensitivity of two different real-time PCR assays was evaluated for the detection of the varicella-zoster virus (VZV) genome: LightCycler PCR and TaqMan PCR. Auricular skin cells and saliva were sampled from 201 patients with facial nerve paralysis. A hundred and seventy-one of these patients were diagnosed clinically with Bell's palsy, and the remaining 30 with Ramsay Hunt syndrome. In 30 specimens obtained from Ramsay Hunt syndrome patients, VZV DNA was detected in 26 skin and 3 saliva specimens using the LightCycler PCR, while 28 skin and 9 saliva specimens were positive using the TaqMan PCR. None of the patients with Bell's palsy were positive for VZV by the LightCycler PCR, whereas five of these patients were positive by the TaqMan PCR. The TaqMan PCR assay has a better sensitivity compared to the LightCycler PCR for the detection of VZV genome from patients with facial palsy. Further study is required to develop a more sensitive real-time PCR.

Chickenpox↗
PubMed2006

Synergistic effect of vitamin K2 and prostaglandin E2 on cancellous bone mass in hypophysectomized young rats.

Hypophysectomy (HX) results in cessation of bone growth and cancellous osteopenia in rats. It has been reported that prostaglandin E2 (PGE2) improves cortical and cancellous bone mass in HX rats. The purpose of the present study was to examine whether combined administration of vitamin K2 and PGE2 would have a more beneficial effect on bone than single administration of either alone in HX rats. Forty-three female Sprague-Dawley rats, 6 weeks of age, were randomized by the stratified weight method into five groups: intact controls, HX, HX + vitamin K2 (30 mg/kg, p.o., daily), HX + PGE2 (0.83 mg/kg, i.m., 5 days a week), and HX + vitamin K2 + PGE2. The duration of the experiment was 4 weeks. There was a reduction in cancellous bone volume/total tissue volume (BV/TV) of the proximal tibial metaphysis and a reduction in total tissue area and cortical area (Ct.Ar) of the tibial diaphysis. Vitamin K2 did not affect cancellous BV/TV or Ct.Ar. On the other hand, PGE2 attenuated the loss of cancellous BV/TV in association with higher bone formation rate/bone surface (BFR/BS) and eroded surface (ES)/BS compared with intact controls. PGE2 also increased percent Ct.Ar compared with nontreated HX rats as a result of attenuation of a decrease in periosteal BFR/BS. Vitamin K2 had a synergistic effect with PGE2 on cancellous BV/TV as a result of the suppression of an increase in ES/BS observed by PGE2 treatment. These results suggested that PGE2 had an anabolic action on cancellous and cortical bone and that despite no apparent effect of vitamin K2 on bone, it had a synergistic effect with PGE2 on cancellous bone mass in young HX rats.

Animals↗
PubMed2006

Prevalence of premenstrual syndrome and premenstrual dysphoric disorder in Japanese women.

To investigate the prevalence and impact of premenstrual symptoms in Japanese women, we developed the PSQ "The Premenstrual Symptoms Questionnaire" for the screening of premenstrual symptoms. The PSQ translates DSM-IV criteria into a rating scale with degrees of severity. One thousand one hundred and eighty-seven Japanese women between the ages of 20 and 49 yrs, who were seen at a clinic for uterine cancer screening, were assessed regarding their premenstrual symptoms using the PSQ. As many as 95% of these women were found to suffer from premenstrual symptoms. The rates of prevalence of moderate to severe PMS and PMDD in Japanese women were 5.3 and 1.2%, respectively, which are lower than those in Western women. Only 5.3% of women with moderate to severe PMS and PMDD were treated. The results of this study suggest that race and ethnicity influence the expression of premenstrual symptoms and that the current state of medical care for Japanese women with moderate to severe PMS and PMDD is not satisfactory.

Adolescent↗
PubMed2006

Involvement of Sp-1 in the regulation of the Id-1 gene during trophoblast cell differentiation.

Id-1, a member of the helix-loop-helix transcription factor family, inhibits the differentiation of Rcho-1 cells, which were derived from rat choriocarcinoma and consist of trophoblast stem cells. Id-1 is expressed at a high level in undifferentiated trophoblast stem cells and then down-regulated during early differentiation, and is thought to be a key regulator in the trophoblast giant-cell differentiation pathway. In this study, we analyzed the signaling mechanism regulating the high expression levels of Id-1 in undifferentiated Rcho-1 cells. Promoter deletion analysis revealed that a 31-bp sequence (Box-2 region), located between -200 and -169bp in the Id-1 promoter is necessary for the promoter activity. Electrophoretic mobility shift assays and DNA affinity precipitation assays showed that Box-2-binding activity was decreased during differentiation and that Sp-1 protein bound to this sequence. The protein level of Sp-1 was decreased during the differentiation. These results suggest that the Sp-1 protein level may regulate the Box-2-binding activity and the trophoblast giant-cell differentiation.

Animals↗
PubMed2006

Quantitative analysis of amyloid plaques in a mouse model of Alzheimer's disease by phase-contrast X-ray computed tomography.

Densely aggregated beta-amyloid peptides are believed to play a key role in the pathogenesis of Alzheimer's disease. Amyloid plaques are a potential target for molecular imaging to determine the clinical status of Alzheimer's disease. Phase-contrast X-ray imaging combined with computed tomography is a promising technique that can be used to visualize the physical density of structures in biological tissues non-invasively, and without the use of imaging agents. Using brain tissue isolated from a mouse model of Alzheimer's disease, we show that beta-amyloid 40-positive/beta-amyloid 42-positive amyloid plaques, but not beta-amyloid 40-negative/beta-amyloid 42-positive amyloid plaques, exist as high-density aggregates that can be specifically detected by phase-contrast X-ray computed tomography. The phase-contrast X-ray computed tomography detected beta-amyloid 40-positive/beta-amyloid 42-positive amyloid plaques in three-dimensions with an extremely high sensitivity comparable to that of histological analysis, and also enabled the load of amyloid plaques to be quantified. Furthermore, the use of phase-contrast X-ray computed tomography reveals that the physical density of beta-amyloid 40-positive/beta-amyloid 42-positive amyloid plaques increases with age, and that the large volume, high-density, amyloid plaques that are specifically observed in aged Alzheimer's disease mice are closely associated with neuritic dystrophy. These results demonstrate that phase-contrast X-ray computed tomography is a highly sensitive imaging technique for analyzing dense-cored amyloid plaques in postmortem samples, and is beneficial in elucidating amyloid pathophysiology in Alzheimer's disease.

Aging↗
PubMed2006

Serodiagnostic potential of chemically synthesized glycosphingolipid antigens in an enzyme-linked immunosorbent assay for alveolar echinococcosis.

In the serodiagnosis of alveolar echinococcosis, the detection of specific reactions against not only protein but also carbohydrate antigen is useful and both antigens supplement each other. Though recombinant protein antigens have recently advanced, the preparation of carbohydrate antigen still depends on extraction from crude antigens. In the latter case, it is not conventional to obtain carbohydrate antigen as a single component for examination and research. Therefore, chemically synthesized carbohydrate antigens were prepared for serodiagnosis by the enzyme-linked immunosorbent assay (ELISA). Four antigens with the structure of glycosphingolipids from Echinococcus multilocularis were examined and one antigen, Galbeta1-6(Fucalpha1-3)Galbeta1-6Galbeta1-ceramide, was found to show significant serodiagnostic potential in differentiating alveolar from cystic echinococcosis.

Animals↗
PubMed2006

Oesophago-gastric junction opening function: assessment using ultrasound imaging and the effects of atropine.

Relaxation and opening of the oesophago-gastric junction (OGJ) is crucial for oesophageal transport. A novel ultrasound technique was used to determine OGJ opening, before and after atropine, in 12 normals. An ultrasound probe, a solid-state pressure transducer and an infusion tube were placed inside a 20-mm diameter bag, which was placed across the OGJ. At various bag pressures ultrasound transducer was pulled across the bag. Acquired B-mode ultrasound images were converted into M-mode image to display the oesophagus, OGJ and stomach. At low bag-pressure (< 20 mmHg), the OGJ but not oesophagus and stomach, is collapsed around the bag. Increasing bag pressure results in gradual opening of the OGJ from distal end. M-mode image identified the narrowest region of OGJ and corresponding cross-sectional area (CSA) was measured. Mean bag pressure to initial OGJ opening was 18 mmHg. Linear relationship between bag-pressure and OGJ-CSA was observed. Atropine reduced opening bag pressure and shifted the OGJ pressure-CSA curve upward without altering slope, i.e. compliance. Our novel ultrasound technique to study the OGJ opening function shows two distinct components; firstly, related to the tonic OGJ contraction and secondly, to passive or viscoelastic properties of the OGJ.

Adult↗
PubMed2006

Dissecting Ascaris glycosphingolipids for immunomodulatory moieties--the use of synthetic structural glycosphingolipid analogues.

We have previously shown glycosphingolipids of Ascaris suum to have phosphorylcholine (PC) and non-PC immunomodulatory moieties. In the present study we further investigated the nature of the immunomodulatory moieties by employing three synthetic glycosphingolipids each possessing features of the original molecule to examine effects on macrophage and dendritic cell (DC) cytokine production and surface co-stimulatory molecule expression. Compound 2, which lacked PC but contained ceramide, had no effect on either macrophages or DCs. Surprisingly however, Compound 1, which contained PC and hence arguably most resembled the native material, had, with the exception of a small increase in surface antigen expression, no immunomodulatory properties. Conversely, Compound 3, which contained PC but was otherwise least like the native molecule, demonstrated a number of effects on both macrophages and DCs, including induction of Th-1/pro-inflammatory cytokines, inhibition of such cytokines induced by IFN-gamma/LPS and increased expression of co-stimulatory molecules. Taken together these results indicate: (i) that although PC is an immunomodulatory component of the native molecule other structural feature are necessary to allow it to act; (ii) that carbohydrate rather than ceramide is likely to represent a non-PC immunomodulatory moiety; and (iii) that synthetic PC-containing molecules have the potential to act as immunomodulatory drugs.

Animals↗
PubMed2006

Immunohistological evaluation of Ki-67, p63, CK19 and p53 expression in oral epithelial dysplasias.

BACKGROUND: Oral squamous cell carcinoma develops through a multistep of genetic mutations, and the process can be morphologically recognized as oral epithelial dysplasia. To evaluate the hypothesis that distributional alterations of proliferating and stem cells may be a useful index to estimate the grading and development of epithelial dysplasia, we examined the distribution patterns according to stratified cell layers. METHODS: Sixty-two oral dysplasia cases according to the histological grades were immunohistologically examined and the nuclear expression of Ki-67 and p63 antigens was counted according to epithelial layers as labeling index. RESULTS: The Ki-67 labeling index in the basal and suprabasal layers and that of p63 in the basal layer showed a significant difference between low- and high-grade groups of epithelial dysplasia. CONCLUSION: The architectural alteration of proliferating cell and stem cell distribution in the layers of epithelial dysplasias may provide useful information to evaluate the grading of oral epithelial dysplasias.

Adult↗
PubMed2005

Effects of lithium on endolymph homeostasis and experimentally induced endolymphatic hydrops.

There is evidence to suggest that water homeostasis in the inner ear is regulated via the vasopressin (VP)-aquaporin 2 (AQP2) system in the same fashion as in the kidney. The VP-AQP2 system in the kidney is well known to be inhibited by lithium, resulting in polyuria due to a decrease in reabsorption of water in the collecting duct of the kidney. Therefore, lithium is also likely to inhibit the VP-AQP2 system in the inner ear, and consequently exert some influence on inner ear fluid homeostasis. In this study, we investigated the effects of lithium on AQP2 expression in the rat inner ear, and on the cochlear fluid volume in hydropic ears of guinea pigs. A quantitative PCR study revealed that lithium reduced AQP2 mRNA expression in the cochlea and endolymphatic sac. Lithium application also decreased the immunoreactivity of AQP2 in the cochlea and endolymphatic sac. In a morphological study, lithium intake significantly reduced endolymphatic hydrops dose-dependently. These results indicate that lithium acts on the VP-AQP2 system in the inner ear, consequently producing a dehydratic effect on the endolymphatic compartment.

Animals↗
PubMed2005

STAT3-mediated constitutive expression of SOCS3 in an undifferentiated rat trophoblast-like cell line.

In the trophoblast, constitutive expression of SOCS3 is important for the negative regulation of trophoblast giant cell differentiation. In this study, we analyzed the signaling pathway regulating the constitutive SOCS3 expression in undifferentiated Rcho-1 cells, which were derived from rat choriocarcinoma and consist of trophoblast stem cells that are capable of differentiating to trophoblast giant cells in vitro. PD98059, an MEK inhibitor, repressed the SOCS3 expression but AG490, a JAK2 inhibitor, did not. Promoter deletion analysis revealed that the STAT response element (SRE) in the SOCS3 promoter is necessary for the promoter activity. Overexpression of STAT3 increased the SOCS3 promoter activity, whereas expression of dominant-negative STAT3 reduced it. Constitutive STAT3 tyrosine phosphorylation that was not inhibited by either AG490 or PD98059 was demonstrated. Electrophoretic mobility shift assays showed the existence of a protein that bound to SRE and was supershifted with STAT3 antibody. This binding reaction was inhibited by neither AG490 nor PD98059. These findings imply that the ERK/MAPK pathway and STAT3 are involved in the constitutive activation of SOCS3 in undifferentiated Rcho-1 cells. Moreover, they indicate that the constitutive STAT3 tyrosine phosphorylation and the DNA binding activity of STAT3 do not depend on the ERK/MAPK or JAK kinase pathway. These results suggest that a trophoblast-specific STAT3 activation pathway is important for the regulation of giant cell differentiation.

Animals↗
PubMed2005

Raloxifene and vitamin K2 combine to improve the femoral neck strength of ovariectomized rats.

We evaluated the skeletal effects of two osteoporosis therapies in an ovariectomized rat model, raloxifene and vitamin K2, as well as the vitamin K2 plus raloxifene (K + Ral) combination. In two studies, 6-month-old rats were ovariectomized, except for sham-ovariectomy controls (Sham), and dosed orally with vehicle, 30 mg/kg vitamin K2, 1 mg/kg raloxifene, or the combination of K + Ral for 6 weeks following surgery. Vitamin K2 had no effect on serum estrogen, low-density lipoprotein cholesterol (LDL-C), or urinary deoxypyridinoline levels, but slightly increased osteocalcin levels compared to Ovx. Raloxifene lowered total cholesterol, LDL-C, osteocalcin, and urinary deoxypyridinoline levels to below Ovx levels, while having no effect on estrogen levels. Raloxifene, but not vitamin K2, prevented ovariectomy-induced loss of bone in the distal femoral metaphysis and proximal tibial metaphysis, as did the K + Ral combination. Raloxifene, but not vitamin K2, partially prevented, loss of vertebral bone mineral density (BMD), whereas K + Ral had BMD greater than that of Ovx. Vitamin K2 increased bone formation rate to above Ovx, whereas raloxifene and K + Ral reduced bone formation rate to Sham levels. Vitamin K2 had no effect on eroded surface compared to Ovx, while raloxifene and K + Ral reduced eroded surface to Sham levels. Groups were not different in the BMD of femoral midshaft; however vitamin K2 was observed to increase periosteal mineralizing surface of the tibial shaft to above Ovx, while raloxifene reduced periosteal mineralizing surface toward Sham levels. Femoral neck strength was not different between groups, indicating no significant beneficial effect of either raloxifene or vitamin K2 at this site. However, K + Ral had reproducibly greater femoral neck strength than Ovx or Sham. Raloxifene, but not vitamin K2, partially prevented loss of lumbar vertebra strength; but K + Ral was not different from Sham or Ovx. Therefore, raloxifene and vitamin K2 had complementary effects on bone resorption and formation activities, respectively, resulting in a reproducible, significant improvement of femoral neck strength. These rat data suggest interesting therapeutic possibilities that may require clinical verification.

Administration, Oral↗
PubMed2005

Effects of vitamin K2 administration on calcium balance and bone mass in young rats fed normal or low calcium diet.

OBJECTIVE: The purpose of this study was to examine the effects of vitamin K2 administration on calcium balance and bone mass in young rats fed a normal or low calcium diet. METHODS: Forty female Sprague-Dawley rats, 6 weeks of age, were randomized by stratified weight method into four groups with 10 rats in each group: 0.5% (normal) calcium diet, 0.1% (low) calcium diet, 0.5% calcium diet + vitamin K2 (menatetrenone, 30 mg/100 g chow diet), and 0.1% calcium diet + vitamin K2. After 10 weeks of feeding, serum calcium and calciotropic hormone levels were measured, and intestinal calcium absorption and renal calcium reabsorption were evaluated. Bone histomorphometric analyses were performed on cortical bone of the tibial shaft and cancellous bone of the proximal tibia. RESULTS: Feeding a low calcium diet induced hypocalcemia, increased serum parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D [1,25(OH)2D] levels with decreased serum 25-hydrovyvitamin D [25(OH)D] level, stimulated intestinal calcium absorption and renal calcium reabsorption, and reduced cortical bone mass as a result of decreased periosteal bone gain and enlarged marrow cavity, but did not significantly influence cancellous bone mass. Vitamin K2 administration in rats fed a low calcium diet stimulated renal calcium reabsorption, retarded the abnormal elevation of serum PTH level, increased cancellous bone mass, and retarded cortical bone loss, while vitamin K2 administration in rats fed a normal calcium diet stimulated intestinal calcium absorption by increasing serum 1,25(OH)2D level, and increased cortical bone mass. CONCLUSION: This study clearly shows the differential response of calcium balance and bone mass to vitamin K2 administration in rats fed a normal or low calcium diet.

Animals↗
PubMed2005

Neutron spin-echo studies on dynamic and static fluctuations in two types of poly(vinyl alcohol) gels.

We report neutron spin-echo measurements on two types of poly(vinyl alcohol) (PVA) gels. The first is PVA gel in a mixture of dimethyl sulfoxide (DMSO) and water with volume ratio 60/40 , and the second is PVA gel in an aqueous borax solution. The observed normalized intermediate scattering functions I (Q,t) /I (Q,0) are very different between them. The former I (Q,t) /I (Q,0) shows a nondecaying component in addition to a fast decay, but the latter does not have the nondecaying one. This clearly indicates that the fluctuations in the former PVA gel consist of static and dynamic fluctuations whereas the latter PVA gel does include only the dynamic fluctuations. The dynamic fluctuations of the former and latter gels have been analyzed in terms of a restricted motion in the network and Zimm motion, respectively, and the origins of these motions will be discussed.

Journal Article↗
PubMed2004

Investigation of color motion using MEG and binocular rivalry stimuli.

Previous psychophysical studies have reported a few hundred millisecond difference in the reaction time (RT) to luminance versus color motion in low speed condition. Electroencephalogram (EEG) studies have reported a small difference between initial responses to luminance and color motion, but a big difference comparable to that reported in psychophysical studies has not been observed. The present study aimed to investigate late responses in low speed condition in order to clarify the difference of RTs between luminance and color motion. In general, measurement of the late responses is difficult because the late responses are weaker than the initial responses. A previous EEG study of binocular rivalry has reported that binocular rivalry stimuli amplify late responses. Therefore, we used binocular rivalry stimuli to measure late responses. Visual evoked fields were recorded with a whole-head MEG system. A rivalry-related field (RRF) was obtained from the subtraction between the rivalry and a control condition. The RRF was measured between 400 to 550 ms after the stimulus onset for each motion. Results of source localizations of RRFs had similar positions for both the luminance and the color motion. No statistically significant difference between the latencies of the two RRFs was found.

Adult↗
PubMed2004

Enhanced neural responses correlated with perceptual binding of color and motion.

When both color and motion direction of visual stimuli are alternated in physical synchrony at a relatively higher frequency (approximately 2 Hz), the changes in motion direction are perceived to be delayed. On the other hand, color and motion direction changes are perceived to be in phase when the motion direction changes precede the color changes by about 100 ms [Moutoussis, 1997]. In the present study, we utilized this phenomenon to investigate the neural mechanisms underlying the binding of color and motion based on the temporal synchrony. Magnetoencephalogram (MEG) was recorded for ten human subjects under the following four conditions: color change (color), motion direction change (motion), and simultaneous color and motion direction changes (color+motion) in perceptual synchrony (physical asynchrony) or in perceptual asynchrony (physical synchrony). The wavelet analysis was applied on these MEGs to study the neural responses in time-frequency domain. The interactions of color and motion responses, defined by [color+motion]-([color]+[motion]), were calculated in time-frequency domain for both perceptually synchronous and asynchronous conditions. The results showed significantly larger interactions at gamma band (30-35 Hz) under the condition of perceptual synchrony than under the condition of perceptual asynchrony, suggesting that synchronized neural responses at gamma band are related to the synchrony-based binding of visual attributes. This result is consistent with previous studies reporting the correlation of gamma band responses with perceptual grouping [Castelo-Branco, 2000] [Tallon-Baudry, 1996].

Color Perception↗
PubMed2004

A study of relationship between multifocal VEF responses and binocular disparity.

Multifocal visual evoked magnetic field (mfVEF) is useful for shortening the measurement time and/or improving the signal-to-noise ratio of recording, in investigating cortical activities elicited by multiple stimulus patches across the visual field. To record the whole-head mfVEF, we previously developed custom software to deliver multifocal stimuli and to analyze the acquired data, and we applied it to investigation of stereopsis. In the present study, relationship between mfVEF responses and binocular disparity was investigated. Subjects were instructed to fixate a nonius line in the center of a screen, and they were presented with rapid alteration of random-dot (RD) patches. The experiments consisted of a luminance change condition (condition L) and seven binocular disparity conditions (condition BDs) ranging from a crossed disparity of 1 deg to an uncrossed disparity of 1 deg. Each response evoked by one of the RD patches was obtained with the multifocal technique. Although all subjects showed obvious responses in the condition L, only one of the subjects showed obvious responses in condition BDs. The sources of the responses recorded in condition BDs were mainly localized around calcarine sulci according to the known retinotopic cortical representation. The responses obtained in condition BDs showed dependence on binocular disparity in the magnitude and the latency. These results would be the basis for further analysis of brain magnetic responses related to stereopsis.

Adult↗