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H Kawamura

Publications and source records attributed to H Kawamura.

At least 19 recordsLinked to original sources
PubMed2006

Anthropogenic radionuclides in sediment in the Japan Sea: distribution and transport processes of particulate radionuclides.

Distributions of anthropogenic radionuclides ((90)Sr, (137)Cs and (239+240)Pu) in seabed sediment in the Japan Sea were collected during the period 1998-2002. Concentration of (90)Sr, (137)Cs and (239+240)Pu in seabed sediment was 0.07-1.6 Bq kg(-1), 0.4-9.1 Bq kg(-1) and 0.002-1.9 Bq kg(-1), respectively. In the northern basin of the sea (Japan Basin), (239+240)Pu/(137)Cs ratios in seabed sediment were higher and their variation was smaller compared to that in the southeastern regions of the sea. The higher (239+240)Pu/(137)Cs ratios throughout the Japan Basin were considered to reflect production of Pu-enriched particles in the surface layer and substantial sinking of particulate materials in this region. In the southern regions of the Japan Sea (<38 degrees N), both inventories and (239+240)Pu/(137)Cs ratios in sediment were larger than those in the other regions. In the southern Japan Sea, observations suggested that supply of particulate radionuclides by the Tsushima Warm Current mainly enhanced accumulation of the radionuclides in this region.

Cesium Radioisotopes↗
PubMed2006

Evidence of a fcc-hcp transition in aluminum at multimegabar pressure.

The structure phase transition and the equation of state (EOS) of the third-period simple metal Al were investigated at pressure up to 333 GPa by powder x-ray diffraction experiments. The theoretically predicted fcc-hcp transition was observed at the reduced volume V/V0 of 0.509(1), corresponding to the pressure of 217+/-10 GPa. From the obtained pressure-volume data, the pressure derivative of the bulk modulus K0' for the EOS of fcc-Al was determined to be 4.83(3) by fitting to the Vinet formulation with a fixed value 72.7 GPa of K0 obtained from previous ultrasonic experiments.

Journal Article↗
PubMed2006

Aberrant maspin expression in gallbladder epithelium is associated with intestinal metaplasia in patients with cholelithiasis.

OBJECTIVE: Aberrant expression of maspin protein related to DNA hypomethylation in the promoter region is frequently observed in gallbladder carcinomas, whereas the non-tumorous gallbladder epithelium is maspin negative. We investigated maspin expression in non-tumorous gallbladder epithelium in patients with cholelithiasis. METHODS: An immunohistochemical study of maspin expression was performed in 69 patients with cholelithiasis and 30 patients with gastric cancer without cholelithiasis. RESULTS: Immunoreactivity for maspin was observed in focal and patchy regions of the gallbladder epithelium. Positive immunoreactivity for maspin was significantly associated with the presence of intestinal metaplasia in patients with cholelithiasis (p<0.05). CONCLUSION: The high incidence of aberrant maspin expression in both intestinal metaplasia and carcinoma of the gallbladder supports the assumption that intestinal metaplasia of the gallbladder may predispose to gallbladder carcinoma.

Adult↗
PubMed2006

Changes in condylar mobility and radiographic alterations after treatment in patients with non-reducing disc displacement of the temporomandibular joint.

OBJECTIVES: The purpose of this study was to examine changes in condylar mobility and morphological changes in the affected condyles after treatment in patients with non-reducing disc displacement of the temporomandibular joint (TMJ). METHODS: Changes in condylar mobility and morphological changes of the condyle were examined radiographically in 55 patients who were diagnosed as having non-reducing disc displacement of the unilateral TMJ and had received pumping with injection of sodium hyaluronate. In all patients, standardized lateral oblique transcranial radiographs and panoramic jaw tomograms were taken both at initial visit and at 12 months or more follow-up (mean 28.1 months after treatment; range 12-104 months). 42 joints in 21 persons with no current or previous TMJ symptoms served as a control. RESULTS: Clinical signs and symptoms improved after treatment in the patients. Condylar mobility significantly increased after treatment in patients (P<0.001), although it did not reach levels of the control group. Frequency of radiographic changes of the condyle significantly increased after treatment (P<0.005). In most of the patients, no or only mild changes were observed. Frequency of changes of the condyle in patients at follow-up was significantly greater than that in controls (P<0.001). CONCLUSIONS: In the patients, condylar mobility increased in the subsequent course after treatment. However, bony changes of the condyle appeared more frequently. Long term-follow-up after treatment on bony changes of the condyle seems to be necessary in patients with non-reducing disc displacement of the TMJ.

Adolescent↗
PubMed2006

[Usefulness of ultrasonically activated scalpel for pulmonary resection in video-assisted thoracoscopic surgery].

We evaluated the reliability and efficacy of the ultrasonically activated scalpel (Harmonic Scalpel) for pulmonary resection in video-assisted thoracoscopic surgery (VATS). Fifty-six cases of primary or metastatic lung cancer with history of lobectomy or segmentectomy from July 2003 to June 2006 were investigated. The ultrasonically activated scalpel was used to separate aborted lobulation and segment in the surgery. The outcome of the operation using the ultrasonically activated scalpel revealed the mean operation time of 224.5 minutes and mean blood loss volume of 116.7 ml. The chest drainage catheter was removed at the postoperative day 3.4 and hospitalization lasted 10.4 days on average. By means of statistical analysis, no significant differences were noted when compared with the cases using surgical stapler to separate the lobules or segments of the lungs. Histopathological results showed destruction of alveolar structures and denaturation of cells at the cut surface of the resected lung through the use of the ultrasonically activated scalpel. This method resulted in good lung expansion and preservation of the residual lung volume. Furthermore, it prevented postoperative air leakage by appropriate treatment to the cut surfaces of the residual lung. Indeed, the method appears to be useful in the separation of lung tissues in severe aborted lobulation and segmentectomy by VATS.

Aged↗
PubMed2005

Analysis of feeding behavior with direct linear transformation.

AIM: The sucking pattern of term infants is composed of a rhythmic alteration of expression and suction movements. The aim is to evaluate if direct linear transformation (DLT) method could be used for the assessment of infant feeding. SUBJECT AND METHODS: A total of 10 gnormalh infants and two infants with neurological disorders were studied using DLT procedures and expression/suction pressure recordings. Feeding pattern of seven gnormalh infants were evaluated simultaneously recording DLT and pressures. The other infants were tested non-simultaneously. We placed markers on the lateral angle of the eye, tip of the jaw, and throat. The faces of infants while sucking were recorded in profile. The jaw and throat movements were calculated using the DLT procedure. Regression analysis was implemented to investigate the relationship between suction and expression pressures and eye-jaw and eye-throat movement. All regression analyses investigated univariate relationships and adjusted for other covariates. RESULTS: Ten gnormalh infants demonstrated higher suction pressure than expression pressure, and their throat movements were larger than jaw movements. Two infants with neurological problems did not generate suction pressure and demonstrated larger movements in their jaw than throat. The simultaneous measurement (n=7) showed a significant correlation, not only between eye-jaw distance and the expression pressure, but also between eye-throat distance and suction pressure. The change in the eye-jaw distance was smaller than the changes in the eye-throat distance in gnormalh infants (p<0.001). CONCLUSIONS: The DLT method can be used to evaluate feeding performance without any special device.

Humans↗
PubMed2005

Short and long term analysis of heart rate variations in spontaneously hypertensive rats: effects of DSP-4 administration.

The purpose of this study was to investigate whether or not central noradrenergic neurons were involved in the time structure of circadian variation of heart rate (HR) in hypertension. We used spontaneously hypertensive rats (SHR(Izm)) and normotensive controls (Wistar Kyoto rats, WKY(Izm)). We selectively destroyed the noradrenergic neurons in the central nervous system (CNS) by administering noradrenergic neurotoxin, N-(2-chloroethy)-N-ethyl-2-bromobenzylamine (DSP4). Frequency domain measures of variation of HR (VHR) were obtained using the maximum entropy method. The 24-h time frame in VHR is usually dominant in both SHR(Izm) and WKY(Izm). Fourteen days after the administering of DSP4, the mean 24-h systolic arterial pressure (SAP) remained higher in SHR(Izm) than in WKY(Izm). After chemical lesion, ultradian rhythms (12-, 8-, 6-, and 4-h periods) in VHR became more remarkable in both SHR(Izm) and WKY(Izm) than before chemical lesion. Before chemical lesion, an inverse relationship existed between frequency and power spectral density in VHR, demonstrating 1/f(beta) characteristics. The slope of 1/f(beta) in VHR did not differ between SHR(Izm) and WKY(Izm). After the chemical lesion it did not also differ from that of each strain in control period (before lesion). Therefore, the noradrenergic neurons may not affect the time structure of HR in SHR(Izm) and WKY(Izm) for short-term time analysis. However, the intact noradrenergic neurons in CNS may be important to keep normal cardiac autonomic function in SHR(Izm) for long-term analysis.

Animals↗
PubMed2005

Natural course of non-reducing disc displacement of the temporomandibular joint: changes in electromyographic activity during chewing movement.

The purpose of this study is to examine whether electromyographic activity (EMG) during chewing movement changes towards the control level spontaneously in the subsequent course after diagnosis in patients with non-reducing disc displacement of the temporomandibular joint (TMJ) who do not receive any treatment. In 15 such patients, EMG data were examined at initial visit and at a mean follow-up of 21.7 months. As a control, 23 persons who had no TMJ dysfunction were studied. The results of EMG were compared among patients at initial visit, those at follow-up, and controls. The patients' clinical signs and symptoms were alleviated during the follow-up period. Duration of muscle contraction, cycle time and integrated EMG value (IEMG) at initial visit in patients were significantly different from those in the controls. In patients, IEMG for chewing-side masseter during chewing in the TMJ-affected side was greater at follow-up (14.2 +/- 8.01 microV s) than that at initial visit (10.5 +/- 3.69 microV s) (P < 0.05). In patients, duration of muscle contraction or cycle time at follow-up was not different from that at initial visit. Patients with non-reducing disc displacement of the TMJ showed spontaneous increasing of IEMG without any treatment in the subsequent course after diagnosis, coupled with improvement of clinical signs and symptoms. Duration of muscle contraction or cycle time did not change towards the control level. The results presented are useful as control data to understand the true effect of a particular treatment for patients with non-reducing disc displacement of the TMJ.

Adolescent↗
PubMed2005

Validity of an oblique posterior condylar radiographic view for revision total knee arthroplasty.

We have previously developed a radiographic technique, the oblique posterior condylar view, for assessment of the posterior aspect of the femoral condyles after total knee arthroplasty. The purpose of this study was to confirm the validity of this radiographic view based upon intra-operative findings at revision total knee arthroplasty. Lateral and oblique posterior condylar views were performed for 11 knees prior to revision total knee arthroplasty, and radiolucent lines or osteolysis of the posterior aspect of the femoral condyles were identified. These findings were compared with the intra-operative appearance of the posterior aspects of the femoral condyles. Statistical analysis showed that sensitivity and efficacy were significantly better for the oblique posterior condylar than the lateral view. This method can, therefore, be considered as suitable for routine follow-up radiographs of the femoral component and in the pre-operative planning of revision surgery.

Aged↗
PubMed2004

Estimation of internal radiation dose to the adult Asian population from the dietary intakes of two long-lived radionuclides.

Daily dietary intakes of two naturally occurring long-lived radionuclides, 232Th and 238U, were estimated for the adult population living in a number of Asian countries, using highly sensitive analytical methods such as instrumental and radiochemical neutron activation analysis (INAA and RNAA), and inductively coupled plasma mass spectrometry (ICP-MS). The Asian countries that participated in the study were Bangladesh (BGD), China (CPR), India (IND), Japan (JPN), Pakistan (PAK), Philippines (PHI), Republic of Korea (ROK) and Vietnam (VIE). Altogether, these countries represent more than 50% of the world population. The median daily intakes of 232Th ranged between 0.6 and 14.4 mBq, the lowest being for Philippines and the highest for Bangladesh, and daily intakes of 238U ranged between 6.7 and 62.5 mBq, lowest and the highest being for India and China, respectively. The Asian median intakes were obtained as 4.2 mBq for 232Th and 12.7 mBq for 238U. Although the Asian intakes were lower than intakes of 12.3 mBq (3.0 ug) 232Th and 23.6 mBq (1.9 ug) 238U proposed by the International Commission on Radiological Protection (ICRP) for the ICRP Reference Man, they were comparable to the global intake values of 4.6 mBq 232Th and 15.6 mBq 238U proposed by the United Nation Scientific Commission on Effects of Radiation (UNSCEAR). The annual committed effective doses to Asian population from the dietary intake of 232Th and 238U were calculated to be 0.34 and 0.20 microSv, respectively, which are three orders of magnitude lower than the global average annual radiation dose of 2400 microSv to man from the natural radiation sources as proposed by UNSCEAR.

Adult↗
PubMed2004

Dietary intakes of seven elements of importance in radiological protection by asian population: comparison with ICRP data.

Within the framework of a Coordinated Research Project (CRP) organized by the International Atomic Energy Agency, Vienna, the daily dietary intakes of seven elements by adult populations living in nine Asian countries were estimated. The countries that participated in the study were Bangladesh, China, India, Indonesia, Japan, Pakistan, Philippines, South Korea (Republic of Korea, ROK), and Vietnam and together they represented more than half of the world population. The seven elements studied were calcium, cesium, iodine, potassium, strontium, thorium, and uranium. These elements have chemical and biological similarity to some of the radionuclides abundantly encountered during nuclear power production and therefore data on these elements could provide important information on their biokinetic behavior. Analyses of diet samples for these seven elements were carried out using highly sensitive and reliable analytical techniques. One thousand one hundred and sixty analytical determinations were made on two hundred and twenty samples of typical diets consumed in these countries to estimate the daily intakes of these elements by the adult Asian population. The median daily dietary intakes for the adult Asian population were found to be 0.45 g calcium, 7 microg cesium, 90 microg iodine, 1.75 g potassium, 1.65 mg strontium, 1 microg thorium, and 1 microg uranium. When compared with the intakes proposed for ICRP Reference Man by International Commission for Radiological Protection, these intakes were lower by factors of 0.41 for calcium, 0.7 for cesium, 0.45 for iodine, 0.53 for potassium, 0.87 for strontium, 0.33 for thorium, and 0.52 for uranium. The lower daily intakes of calcium, cesium, and iodine by Asian population could be due to significantly lower consumption of milk and milk products, which are rich in these elements. The significantly lower intake of calcium in most of the Asian countries may lead to higher uptake of fission nuclide 90Sr and could result in perhaps higher internal radiation dose. The use of highly sensitive and reliable analytical methods resulted in accurate and lower intake values obtained for thorium and uranium, which suggest that radiation dose from their ingestion at natural background levels is likely to be lower than what may be concluded from ICRP data.

Asia↗
PubMed2004

Contents of cesium, iodine, strontium, thorium, and uranium in selected human organs of adult asian population.

Contents of cesium, iodine, strontium, thorium, and uranium in some selected human organs were estimated for adult Asian population using data obtained in four Asian countries: China, India, Philippines, and Republic of Korea, as part of a Coordinated Research Program of the International Atomic Energy Agency on "Ingestion and Organ contents of elements of importance in radiation protection." These countries together represent more than 40% of the world population. Highly sensitive analytical techniques were employed to measure cesium in skeletal muscle, iodine in thyroid, strontium in skeleton, thorium and uranium in skeleton, liver, kidneys, and lungs where, in comparison to other organs, these elements are present in higher concentrations. The organ contents for adult Asian population, when compared with the corresponding data proposed for Reference Man by International Commission on Radiological Protection (ICRP), showed about 40 times lower kidneys content and about 10 times lower skeleton content of uranium. The content of thorium in skeleton for Asian population was also half of the ICRP Reference Man value. Interestingly, organ contents for the other elements such as iodine in thyroid, cesium in skeletal muscle, and strontium in skeleton were comparable for Asian and the Caucasian population (represented by ICRP Reference Man). Organ contents for these elements were also calculated by applying the new ICRP models of these elements to their daily intakes. The comparison of the calculated and measured organ contents showed that despite uncertainties in the organ content values arising due to the inter-country variations in daily dietary intakes, the contents were within a factor of two to three. This observation is significant since human data both on organ contents and ingestion were obtained at environmental level of intakes. The study suggests that currently available ICRP models for these elements are quite realistic.

Adult↗
PubMed2004

Generation of B220low B cells and production of autoantibodies in mice with experimental amyloidosis: association of primordial T cells with this phenomenon.

To investigate the immunological state in amyloidosis, mice were twice intraperitoneally injected (2-week interval) with casein emulsified in complete Freund's adjuvant. Two weeks after the treatment, amyloid deposits were detected in the spleen and other organs of these mice. The number of lymphocytes yielded by the liver and spleen increased significantly. The most affected lymphocyte subset was found to be B cells, namely, the total number of B cells increased and unusual B220low B cells were newly generated in the liver and spleen. In other words, not only normal B220high B cells but also unusual B220low B cells were detected in these organs of mice with amyloidosis. In parallel with this phenomenon, autoantibodies against denatured DNA were detected in sera. Since such autoantibodies are known to accompany the functional activation of NKT cells, NKT cell-deficient mice were used for the induction of amyloidosis. Such mice showed less formation of amyloidosis and lower levels of autoantibodies in sera. Athymic nude mice were NKT cell-deficient but NK1.1- TCRint cells were present. These athymic mice showed an intermediate induction of amyloidosis. The cytokine profile seen in mice with amyloidosis was the Th0 type, showing simultaneous production of IL-4 and IFNgamma. These results suggest that the generation of B220low B cells and the production of autoantibodies in aid of primordial T cells may be major immunological mechanisms in amyloidosis mice.

Amyloidosis↗