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T Yamaguchi

Publications and source records attributed to T Yamaguchi.

At least 55 records · Page 3Linked to original sources
PubMed2005

Clinical value of multidetector row computed tomography in detecting lymph node metastasis of early gastric cancer.

AIMS: To evaluate the clinical value of multidetector row computed tomography (MDCT) as a pre-operative staging tool for lymph node metastasis in patients with early gastric cancer (EGC). METHODS: In 278 consecutive patients with EGC, lymph node metastasis was evaluated pre-operatively with MDCT at a slice thickness of 2.5mm (n=57), 5.0mm (n=188), or 7.5mm (n=33). RESULTS: Overall accuracy of nodal category from N0 to N3 was 86% for MDCT and 95% for operative assessment. Regarding accuracy in detecting at least one metastatic lymph node, area under curves (AUC) of receiver operating characteristics for 2.5, 5.0, and 7.5-mm slices and assessment during surgery were 0.87, 0.67 and 0.47, and 0.70, which were significantly different (P<0.0001). MDCT image with 2.5-mm could discriminate the presence of lymph node metastasis with diagnostic accuracy: sensitivity 80%; specificity 92%; positive predictive value (PPV) 50%; negative predictive value (NPV) 98%, whereas assessment during surgery was as follows: sensitivity 65%; specificity 98%; PPV 72%; and NPV 97%. CONCLUSIONS: These results suggest that pre-operative assessment with MDCT using thinner slices may detect at least one lymph node metastasis as accurately as assessment during surgery for patients with EGC.

Adenocarcinoma↗
PubMed2005

Effect of the alternative magnetic stimulation on peripheral circulation for regenerative medicine.

Regenerative medicine for patients with peripheral atherosclerosis attracts considerable attention around the world. However, ethical problems persist in gene therapy. This study evaluates the effect of alterative magnetic stimulation on peripheral circulation. The effect of magnetic stimulation as a medical treatment was examined using a thermograph for 11 healthy volunteers. The thermograph was used to measure the rise in skin temperature. The experimental results suggested an improvement in the peripheral circulation. The results of our study suggest the effectiveness of alternative magnetic stimulation on atherosclerosis. We intend to extend our study in order to establish a methodology for regenerative medical treatment for patients with peripheral atherosclerosis. Further, we wish to advance the current research in the field of angiogenesis.

Adult↗
PubMed2005

Cardio-ankle vascular index (CAVI) for the monitoring of the atherosclerosis after heart transplantation.

Atherosclerosis has been reported to progress rapidly after heart transplantation. A quantitative diagnosis is required for the diagnosis of atherosclerosis after heart transplantation. In this study, we compared brachial-ankle pulse wave velocity (baPWV) and cardio-ankle vascular index (CAVI) for the diagnosis. The average values of both baPWV and CAVI in the seven cases after heart transplantation were found to be signif-icantly large in comparison to the average values of the normal healthy people of the same age group. When comparisons were made before and after the heart transplantation in a particular case, CAVI was stable and baPWV changed sharply. A lot of parameters such as blood pressure, blood volume, etc. have been reported to influence baPWV. The results of this study suggested that CAVI was a stable parameter in comparison to baPWV even after heart transplantation. Thus, CAVI may be useful in the diagnosis of arteriosclerosis after heart transplantation.

Adolescent↗
PubMed2005

Chaos analysis of electro encephalography and control of seizure attack of epilepsy patients.

In order to evaluate the EEG of patients with epilepsy, chaos analysis was performed for the subdural EEG time series data. The chaos attractor was reconstructed in the phase space and the correlation dimension. KS entropy calculated from the Lyapunov exponents was evaluated. Before the seizure attack, the KS entropy showed a lower value when compared with the time series data recorded during healthy condition. The results of our study suggest that it is possible to predict the seizure attack by the chaos analysis of the EEG signal. Further, we aim at developing an automatic control system for predicting a seizure attack by the use of local cooling of the focus with Peltier elements.

Algorithms↗
PubMed2005

Optimization of adenovirus serotype 35 vectors for efficient transduction in human hematopoietic progenitors: comparison of promoter activities.

Adenoviral gene transfer to hematopoietic stem cells (HSCs)/progenitors would provide a new approach to the treatment of hematopoietic diseases and study of the hematopoietic system. We have previously reported that an adenovirus (Ad) vector composed of whole Ad serotype 35 (Ad35), which belongs to subgroup B, shows efficient gene transfer into human bone marrow CD34+ cells. However, Ad35 vector-mediated transduction into human HSCs/progenitors has not yet been fully optimized. In the present study, we have systematically examined promoter activity in the context of Ad35 vectors in human bone marrow CD34+ cells and primitive CD34+ subsets to optimize the transduction efficiency in human hematopoietic stem/progenitor cells. In the first of the transduction experiments, the improved in vitro ligation method was applied to Ad35 vector construction to allow for simple and efficient production of an E1/E3-deleted Ad35 vector. Using this method, we constructed a series of Ad35 vectors encoding the enhanced green fluorescence protein (GFP) under the control of a variety of strong viral and cellular promoters. Of the six types of promoters tested, significantly higher transduction efficiencies were achieved with the human elongation factor 1alpha promoter (EF1alpha promoter), the human cytomegalovirus (CMV) immediate-early 1 gene enhancer/beta-actin promoter with beta-actin intron (CA promoter), and the CMV promoter/enhancer with the largest intron of CMV (intron A) (CMVi promoter) in the human CD34+ cells and the immature subsets (CD34+ CD38(low/-) and CD34+ AC133+ subsets). In particular, the CA promoter was found to allow for the highest transduction efficiencies in both the whole human CD34+ cells and the immature hematopoietic subsets. Furthermore, the CA promoter-mediated GFP-expressing cells differentiated into progenitor cells of all lineages. These results indicate the construction of an optimized Ad35 vector backbone for efficient transduction into HSCs/progenitors.

Actins↗
PubMed2005

Low-grade follicular lymphoma with t(14;18) presents a homogeneous disease entity otherwise the rest comprises minor groups of heterogeneous disease entities with Bcl2 amplification, Bcl6 translocation or other gene aberrances.

Follicular lymphomas (FL) are morphologically classified into grades 1, 2, 3a and 3b by the World Health Organization. Bcl2, Bcl6 and CD10 are phenotypic markers of FL while the Bcl2 t(14;18) and Bcl6 t(3q27) gene translocations are common genetic changes. However, to date, there has been no integrated analysis based on phenotype, grade and genotype from large numbers of FL cases. We graded 261 cases of FL and determined their phenotypes and gene alterations. According to the antigen markers and gene alterations of 147 cases, we classified FL into typical and the others types. The typical group, which includes 69% cases of FL, is characterized by low histological grade (grade 1, 2), coexpression of BCL2 and CD10 and Bcl2 gene translocation. The rest comprises a small part of low-grade FL without Bcl2 gene translocation and high-grade (grade 3a, 3b) FL. These FLs include some heterogeneous disease entities. They are characterized by high histological grade (87%), no definite expression of BCL2 or CD10 and several kinds of gene aberrances including Bcl2 translocation, Bcl6 translocation, Bcl2 amplification or other unknown gene abnormality. Our findings indicate that typical FL presents a homogeneous disease entity whereas the rest comprises heterogeneous diseases entities.

Biomarkers, Tumor↗
PubMed2005

Dichotomy of all-trans retinoic acid inducing signals for adult T-cell leukemia.

We previously reported that all-trans retinoic acid (ATRA) inhibits growth in human T-cell leukemia virus type 1 (HTLV-1)-positive T-cell lines and fresh cells from patients with adult T-cell leukemia. However, the mechanism of this inhibition is not clear. In the present study, we observed that NF-kappaB transcriptional activity as well as cell growth decreased significantly in HTLV-1-positive T-cell lines in the presence of ATRA. Furthermore, we observed that ATRA reduced HTLV-1 proviral DNA, HTLV-1 genes (gag, tax, or pol mRNA) using the real-time quantitative polymerase chain reaction. SIL-2R was reduced by ATRA in both protein level (culture supernantant) and mRNA level in HTLV-1-positive T-cell lines. Interestingly, ATRA significantly inhibited RT activity similar to azidothimidine (AZT) in HTLV-1-positive T-cell lines. Moreover, AZT inhibited proviral DNA but not NF-kappaB transcriptional activity, and sIL-2R on HTLV-1; however, ATRA inhibited of NF-kappaB, proviral DNA and sIL-2R on HTLV-1. These results suggested that the decrease in sIL-2R induced by ATRA may be caused by the actions of a NF-kappaB inhibitor acting on the NF-kappaB/sIL-2R signal pathway. These results suggested that ATRA could have two roles, as a NF-kappaB inhibitor and as an RT inhibitor.

Adult↗
PubMed2005

Famotidine prevents canine gastric blood flow reduction by NSAIDs.

AIM: To investigate the effect of famotidine on gastric blood flow reduction induced by diclofenac sodium, a common non-steroidal anti-inflammatory drug in Japan, using laser Doppler flowmetry in the canine stomach. METHODS: The gastric mucosal blood flow was measured by laser Doppler flowmetry in 15 healthy male beagles before and 60 min after the administration of diclofenac suppository (1.0 mg/kg) into the rectum. The examination was done in a crossover, single-blinded fashion. All dogs underwent both famotidine (0.5 mg/kg) and placebo (saline) injection simultaneously with the administration of diclofenac. In addition, the tissue concentration of prostaglandin E2 was measured. RESULTS: The blood flow decreased by 18.3 +/- 9.1% in the gastric body, by 26.3 +/- 8.1% in the antrum in the placebo group after the administration of diclofenac sodium, while the decreases seen were significantly smaller in the famotidine group: 3.2 +/- 12.6% in the gastric body and 7.9 +/- 16.5% in the antrum (P = 0.001 for the gastric body, P = 0.0034 for the antrum). Conversely, the percentage of mucosal prostaglandin E2 concentration decrease in each group did not show a significant difference. CONCLUSION: Famotidine alleviates the reduction of gastric blood flow induced by diclofenac sodium. Further, not only mucosal prostaglandins but also gastric acid may play an important role in non-steroidal anti-inflammatory drugs-induced gastric microcirculatory disturbance.

Animals↗
PubMed2005

Clinicopathological features of cutaneous lesions of adult T-cell leukaemia/ lymphoma.

BACKGROUND: Adult T-cell leukaemia/lymphoma (ATLL) is a human malignancy associated with human T-cell leukaemia virus type I (HTLV-I). ATLL frequently involves the skin. OBJECTIVES: To correlate the clinicopathological features and prognosis in patients with ATLL and cutaneous lesions. METHODS: We examined the HTLV-I proviral state and the clinicopathological features of the cutaneous lesions in 80 patients with serum anti-ATL antibody, to clarify the correlation between macroscopic/histopathological findings and prognosis. Southern blot analysis was performed in all cases to detect monoclonal HTLV-I proviral DNA integration. RESULTS: The cutaneous lesions of 46 patients were positive for proviral DNA integration. The median survival time of patients with monoclonal proviral DNA integration in cutaneous lesions was 14 months, which was markedly shorter than that of patients negative for proviral DNA integration (72 months). Of the 46 patients with proviral DNA, 21 had solitary or multiple red nodules (including three with subcutaneous induration), eight had multiple red papules and 17 had erythema. Patients with papules and nodules had poorer prognosis than those with erythema. Histopathologically, the prognosis was poorer in patients with nodular or diffuse infiltration of medium-sized to large lymphoma cells, compared with those with perivascular infiltration of small to medium-sized lymphoma cells. CONCLUSIONS: Our results show a close correlation between clinicopathological features of HTLV-I-associated cutaneous lesions and prognosis.

Adult↗
PubMed2005

The influence of hot pack therapy on the blood flow in masseter muscles.

The purpose of this study was to clarify whether hot pack therapy can change the blood flow of human masseter muscles. Thirty-two healthy subjects with no history of muscle pain in the masticatory system participated and were divided into two groups. One group underwent proper hot pack therapy (hot pack group) and the other underwent sham hot pack therapy (control group). Continuous and non-invasive measurements of haemoglobin volumes and oxygen saturation levels (StO2) were determined with a near-infrared spectroscope. The blood flow parameters were total haemoglobin volume (THb), oxygenated haemoglobin volume (OXHb), deoxygenated haemoglobin volume (deOXHb) and oxygen saturation level (StO2). In hot pack group, results showed that the THb, OXHb and StO2 after the hot pack application were significantly larger than those before the hot pack. In control group, the THb, OXHb, deOXHb, StO2 and heart rates showed no significant differences between the values before and after the sham hot pack application. The THb, OXHb and StO2 after the hot pack application in hot pack group were significantly larger than those in control group, while the deOXHb after the hot pack was significantly smaller than that in control group. The heart rates showed no significant differences between the groups. The results suggest that hot pack therapy can increase regional blood flow of human masseter muscles and creates an advantageous condition for aerobic energy metabolism in the muscles.

Adult↗
PubMed2005

Predominant presence of Streptococcus anginosus in the saliva of alcoholics.

Chronic alcohol consumption is known to be a major risk factor for cancers of the upper aerodigestive tract. The incidence of esophageal cancer (4.4%) in alcoholics is reported to be much higher than that in the Japanese population as a whole (0.0001%). This suggests the presence of specific factors in chronic alcohol consumption-related carcinogenesis. Recently, data showing a significant correlation between Streptococcus anginosus and carcinogenesis in the upper aerodigestive tract have been reported. In this study, the ratio of S. anginosus to oral bacteria in the saliva of 38 alcoholic patients was investigated to determine if there is an association between alcoholic patients and S. anginosus infection. The level of S. anginosus in the saliva from 22 healthy people, 41 esophageal cancer patients, 32 gastritis patients, and 24 periodontitis patients was also investigated and compared to the level in alcoholic patients. In the saliva from esophageal cancer patients, the level of S. anginosus was not significantly different from that of healthy people. The levels of S. anginosus in periodontitis and gastritis patients were also similar. In alcoholics, however, there was an extremely high level of S. anginosus, suggesting that they, rather than healthy people and general esophageal cancer patients, have a high risk for S. anginosus infection.

Adult↗
PubMed2005

Atrial fibrillation as a predictive factor for severe stroke and early death in 15,831 patients with acute ischaemic stroke.

BACKGROUND: Atrial fibrillation (AF) is a common arrhythmia and a major risk factor for stroke. AIMS: To assess whether AF in patients with acute ischaemic stroke is associated with severe stroke and early death. MATERIALS/METHODS: Patients with acute ischaemic stroke (15,831) who were registered in the Japan Multicenter Stroke Investigators' Collaboration registry were analysed. The AF group comprised 3335 (21.1%) patients (median age, 75 years) and the non-AF group comprised 12,496 (78.9%) patients (median age, 70 years). The association between AF and severe stroke and early death was investigated by means of multivariate logistic regression analysis. RESULTS: The admission National Institutes of Health Stroke Scale (NIHSS) score of the AF group was higher than that of the non-AF group (median, 12 v 5; p < 0.0001). Multivariate logistic regression analyses found that female sex, advanced age, AF, and a history of stroke were independent factors associated with severe stroke (NIHSS score, > or = 11). The mortality rate within 28 days after admission was 11.3% in the AF group and 3.4% in the non-AF group (p < 0.0001). Multivariate logistic regression analyses identified older age, AF, and NIHSS score at admission as independent factors associated with early death. CONCLUSION: AF was a predictive factor for severe stroke and early death in acute ischaemic stroke. Careful cardiac evaluation and appropriate treatment are needed to improve outcome in patients with acute stroke and AF.

Acute Disease↗
PubMed2005

Genome-wide linkage analysis of mandibular prognathism in Korean and Japanese patients.

The existence of familial aggregation of mandibular prognathism (MP) suggests that genetic components play an important role in its etiology. In this study, a genome-wide linkage analysis to identify loci susceptible to MP was conducted with 90 affected sibling-pairs in 42 families, comprised of 40 Korean sibling-pairs and 50 Japanese sibling-pairs. Two non-parametric linkage analyses, GENEHUNTER-PLUS and SIBPAL, were applied and detected nominal statistical significance of linkage to MP at chromosomes 1p36, 6q25, and 19p13.2. The best evidence of linkage was detected near D1S234 (maximum Z(lr) = 2.51, P = 0.0012). In addition, evidence of linkage was observed near D6S305 (maximum Z(lr) = 2.23, P = 0.025) and D19S884 (maximum Z(lr) = 1.93, P = 0.0089). Identification of the susceptible genes in the linkage regions will pave the way for insights into the molecular pathways that cause MP, especially overgrowth of the mandible, and may lead to the development of novel therapeutic tools.

Adolescent↗
PubMed2005

Melanocytic matricoma in a dog.

We report a tumor that developed at the root of the tail in a male, 2-year-old Shih Tzu dog. Histologically, the tumor consisted of basaloid epithelial cells, with shadow cells and neoplastic melanocyte proliferation. Immunohistochemically, epithelial components were positive for keratin/cytokeratin but basaloid cells were negative. Mononuclear or multinuclear melanocytes were positive for vimentin, S-100 protein, and HMB-45. In conclusion, this dog was diagnosed with canine melanocytic matricoma on the basis of the similarity of the histologic and immunohistochemical features in humans, and it may be the first case in an animal.

Animals↗
PubMed2005

Development of a wearable computer system with a hands-free operation interface for the use of home health caregiver.

We previously developed a network-based medical care support system called the Hyper Hospital, a computer network with an interface that is dedicated to patient care. In this study, we developed a wearable information system that is designed so that a caregiver can obtain information and control various support devices within the home-care environment. In our system, the wearable computer itself consists of a computer network built into a jacket. Each required function is implemented by a dedicated small computer connected to the in-jacket network. A new function may easily be added to the system by connecting additional computers. A network comprising such a set of single-function computers becomes a highly efficient information system when applied to health care support.

Caregivers↗
PubMed2004

Electron-spin and electron-orbital dependence of the tunnel coupling in laterally coupled double vertical dots.

We employ a new laterally coupled, vertical double dot with a tunable tunnel-coupling gate in a parallel configuration to study the electron spin and orbital dependence of quantum mechanical tunnel coupling on the size of the honeycomb vertices in the small electron numbers regime. We find a transition from the weak coupling regime, where fluctuations in tunnel coupling due to varying electron configuration dominate the anticrossings, to a regime where the two dots coalesce. We apply a magnetic field to ascertain the orbital angular momenta of the Fermi surface eigenstates, which correlate with anticrossing size, and we identify spin pairs with congruent behavior.

Journal Article↗
PubMed2004

Mode-coupling study on the dynamics of hydrophobic hydration.

The molecular motion of water in water-hydrophobic solute mixtures was investigated by the mode-coupling theory for molecular liquids based on the interaction-site description. When the model Lennard-Jones solute was mixed with water, both the translational and reorientational motions of solvent water become slower, in harmony with various experiments and molecular dynamics simulations. We compared the mechanism of the slowing down with that of the pressure dependence of the molecular motion of neat water [T. Yamaguchi, S.-H. Chong, and F. Hirata, J. Chem. Phys. 119, 1021 (2003)]. We found that the decrease in the solvent mobility caused by the solute can essentially be elucidated by the same mechanism: That is, the fluctuation of the number density of solvent due to the cavity formation by the solute strengthens the friction on the collective polarization through the dielectric friction mechanism: We also employed the solute molecule that is the same as solvent water except for the amount of partial charges, in order to alter the strength of the solute-solvent interaction continuously. The mobility of the solvent water was reduced both by the hydrophobic and strongly hydrophilic solutes, but it was enhanced in the intermediate case. Such a behavior was discussed in connection with the concept of positive and negative hydrations.

Journal Article↗