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H Sato

Publications and source records attributed to H Sato.

At least 181 records · Page 10Linked to original sources
PubMed2001

Induction of c-Met proto-oncogene by Epstein-Barr virus latent membrane protein-1 and the correlation with cervical lymph node metastasis of nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is distinctive in head and neck carcinomas for its close association with Epstein-Barr virus and its highly metastatic nature. Up-regulation of cell motility is essential for enhancement of metastatic potential. The expression of c-Met proto-oncogene, a high-affinity receptor for hepatocyte growth factor/scatter factor, has been reported to correlate with metastatic ability of the tumor cell. We observed close association of c-Met expression with cervical lymph node metastasis (P = 0.0272) in 39 NPC specimens studied immunohistochemically. Epstein-Barr virus-encoding latent membrane protein-1 (LMP-1) is a primary oncogene and is suggested to enhance the metastatic property of NPC. Previously, we reported that LMP-1 enhanced the motility of Madin-Darby canine kidney (MDCK) epithelial cells that was mediated by activation of Ets-1 transcription factor. Therefore, we examined the interrelationships of LMP-1, Ets-1, and c-Met. In immunohistochemical studies, the expression of LMP-1, Ets-1, and c-Met correlated significantly with each other in NPC (LMP-1 versus Ets-1, P < 0.0001; Ets-1 versus c-Met, P = 0.0012; LMP-1 versus Met, P = 0.0005). Transfection of LMP-1-expressing plasmid in MDCK cells induced c-Met protein expression. The c-Met protein was also induced by Ets-1 expression, and induction of c-Met by LMP-1 was suppressed by introducing a dominant-negative form of Ets-1 in LMP-1-expressing MDCK cells. These results suggest that LMP-1 induces c-Met through the activation of Ets-1, which may contribute in part to the highly metastatic potential of NPC.

Animals↗
PubMed2001

Three-field lymph node dissection for esophageal cancer in elderly patients over 70 years of age.

BACKGROUND: The risk and benefit of esophagectomy with three-field lymph node dissection has not been well defined in elderly esophageal cancer patients. METHODS: A total of 441 patients underwent three-field lymph node dissection from 1986 to 1998. Patients were divided into two age groups: group 1 consisted of 79 patients aged 70 years or over, and group 2 consisted of 362 patients under 70 years of age. Patients' characteristics and surgical outcomes were compared between groups. Risk factors for morbidity, mortality, and survival of patients in group 1 were further studied by multivariate analysis. RESULTS: Significantly more patients had multiorgan dysfunction preoperatively in group 1 (24; 30.4%) than in group 2 (34; 9.4%, p < 0.001). The overall (65.8% vs 61.6%, p = 0.483) and surgically related complication rates (41.8% vs 52.2%, p = 0.093) were similar, but significantly more organ failure (11.4% vs 5.0%, p = 0.031) and infection (22.8% vs 13.8%, p = 0.045), defined as medical complications, occurred in group 1. There was no significant difference in 30-day (3.8% vs 0.8%, p = 0.074) or in-hospital mortality (7.6% vs 3.3%, p = 0.082) between groups. The overall (40.9% vs 48.1%, p = 0.235) and cause-specific 5-year survivals (55.4% vs 59.1%, p = 0.688) were comparably good in both groups, but the risk of death due to causes other than esophageal cancer was much higher in the elderly (p = 0.028). Multiorgan dysfunction was an independent predictive factor in elderly patients for overall and medical morbidity, overall survival, and risk of death from causes other than esophageal cancer. CONCLUSIONS: Esophagectomy with three-field lymph node dissection could be carried out safely in patients over 70 years of age with satisfactory long-term results. For elderly patients with multiorgan dysfunction, however, less invasive procedures might be more appropriate.

Age Factors↗
PubMed2001

Long-term results using a piezoelectric semi-implantable middle ear hearing device: the Rion Device E-type.

The Rion Device E-type (RDE) has been applied to 39 patients with severe mixed deafness that could not be rehabilitated by surgical means or the conventional hearing aid. Careful follow-up studies have been conducted on all of them to assess clinical and audiologic results. The device could function more than 10 years, affording natural quality of hearing without howling and wearing discomforts. Functional principles of the device, indications, and surgical methods of implantation are described. The failures and delayed problems were also presented together with the preventive measures.

Adult↗
PubMed2001

Experimental and modeling studies on sorption and diffusion of radium in bentonite.

The sorption and desorption behavior of radium on bentonite and purified smectite was investigated as a function of pH, ionic strength and liquid to solid ratio by batch experiments. The distribution coefficients (Kd) were in the range of 10(2) to > 10(4) ml g-1 and depended on ionic strength and pH. Most of sorbed Ra was desorbed by 1 M KCl. The results for purified smectite indicated that Ra sorption is dominated by ion exchange at layer sites of smectite, and surface complexation at edge sites may increase Ra sorption at higher pH region. Reaction parameters between Ra and smectite were determined based on an interaction model between smectite and groundwater. The reaction parameters were then used to explain the results of bentonite by considering dissolution and precipitation of minerals and soluble impurities. The dependencies of experimental Kd values on pH, ionic strength and liquid to solid ratio were qualitatively explained by the model. The modeling result for bentonite indicated that sorption of Ra on bentonite is dominated by ion exchange with smectite. The observed pH dependency was caused by changes of Ca concentration arising from dissolution and precipitation of calcite. Diffusion behavior of Ra in bentonite was also investigated as a function of dry density and ionic strength. The apparent diffusion coefficients (Da) obtained in compacted bentonite were in the range of 1.1 x 10(-11) to 2.2 x 10(-12) m2 s-1 and decreased with increasing in dry density and ionic strength. The Kd values obtained by measured effective diffusion coefficient (De) and modeled De were consistent with those by the sorption model in a deviation within one order of magnitude.

Adsorption↗
PubMed2001

An integrated sorption-diffusion model for the calculation of consistent distribution and diffusion coefficients in compacted bentonite.

A thermodynamic sorption model and a diffusion model based on electric double layer (EDL) theory are integrated to yield a surface chemical model that treats porewater chemistry, surface reactions, and the influence of charged pore walls on diffusing ions in a consistent fashion. The relative contribution of Stern and diffuse layer to the compensation of the permanent surface charge represents a key parameter; it is optimized for the diffusion of Cs in Kunipia-F bentonite, at a dry density of 400 kg/m3. The model is then directly used to predict apparent diffusivities (Da) of Cs, Sr, Cl-, I- and TcO4- and corresponding distribution coefficients (Kd) of Cs and Sr in different bentonites as a function of dry density, without any further adjustment of surface chemical and EDL parameters. Effective diffusivities (De) for Cs, HTO, and TcO4- are also calculated. All calculated values (Da, De, Kd) are fully consistent with each other. A comparison with published, measured data shows that the present model allows a good prediction and consistent explanation of (i) apparent and effective diffusivities for cations, anions, and neutral species in compacted bentonite, and of (ii) Kd values in batch and compacted systems.

Adsorption↗
PubMed2001

Diabetes mellitus prevents ischemic preconditioning in patients with a first acute anterior wall myocardial infarction.

OBJECTIVES: This study was undertaken to assess whether prodromal angina could have beneficial effects in diabetic patients with acute myocardial infarction (AMI). BACKGROUND: Prodromal angina occurring shortly before the onset of AMI is associated with favorable outcomes by the mechanism of ischemic preconditioning. However, little is known about the impact of diabetes on ischemic preconditioning. METHODS: We studied 611 patients with a first anterior wall AMI who underwent emergency catheterization within 12 h after the onset of chest pain: 490 patients without diabetes and 121 patients with non-insulin treated diabetes. Prodromal angina was defined as angina episode(s) occurring within 24 h before the onset of AMI. Serial contrast left ventriculograms were obtained in 424 patients at the time of acute and predischarge catheterization. RESULTS: In non-diabetic patients, prodromal angina was associated with lower peak creatine kinase (CK) value (3,068 +/- 2,647 IU/l vs. 3,601 +/- 2,462 IU/l, p = 0.037), larger increase in left ventricular ejection fraction (LVEF) (10.1 +/- 13.0% vs. 5.8 +/- 13.4%, p = 0.004) and lower in-hospital mortality (3.4% vs. 9.3%, p = 0.015). On the contrary, in diabetic patients, there was no significant difference in peak CK value (3,382 +/- 2,520 IU/l vs. 3,233 +/- 2,412 IU/l, p = NS), the change in LVEF (6.7 +/- 13.8% vs. 7.1 +/- 12.4%, p = NS) and in-hospital mortality (8.8% vs. 11.0%, p = NS) between patients with and patients without prodromal angina. CONCLUSIONS: Prodromal angina limited infarct size, enhanced recovery of LV function and improved survival in non-diabetic patients with AMI. However, such beneficial effects of prodromal angina were not observed in diabetic patients, suggesting that diabetes might prevent ischemic preconditioning.

Aged↗
PubMed2001

The efficacy of glycolic acid for treating wrinkles: analysis using newly developed facial imaging systems equipped with fluorescent illumination.

The clinical characteristics of photodamaged skin, such as coarse and fine wrinkling, can not be quantitatively evaluated from ordinary photographic records. The purpose of this study was to assess the efficacy of glycolic acid (GA) peeling on facial wrinkling, using computer assisted image analysis. This was accomplished with reproducible imaging techniques, which allowed precise repositioning of the subject's face in front of the camera. Two parameters, the change in wrinkle number and the change in wrinkle length were assessed. Although the clinical improvement of wrinkles correlated with both parameters, wrinkle length more precisely reflected the degree of clinical wrinkles, because the wrinkle number appeared to increase as some shallow wrinkles divided into multiple smaller wrinkles during their improvement. Comparison of responses by different age groups showed that the reduction of total wrinkle length was observed in the order of: 50s>30s and 40s>60s>over 70>under 30. The lack of response by subjects over 70 might be due to the nature of their wrinkles being mainly coarse wrinkles rather than fine ones. We next compared the effect of GA by concentration (35, 50 or 70%), but found no significant differences. As the concentration of GA used for treatment was determined by each subject's erythema reaction, our present result suggests that erythema elicited by GA correlates with improvement of wrinkles and that these two phenomena can be induced by a common pathway of GA treatment. This quantitative analysis clearly shows the efficacy and limitation of GA treatment of wrinkles, and might help to disclose the precise mechanisms of GA effects on the skin structure and function.

Adult↗
PubMed2001

Dicationic dithiocarbamate carbapenems with anti-MRSA activity.

A new class of 1 beta-methylcarbapenems bearing a doubly quaternarized 1,4-diazabicyclooctane (DABCO) substituted dithiocarbamate moiety at the C-2 side chain was prepared, and the biological profiles of the compounds, including in vitro and in vivo anti-MRSA activity and DHP-I susceptibility, were evaluated to identify a carbapenem derivative that was superior to BO-3482 (1). As a result, we discovered a 1 beta-methyl-2-[4-(4-carbamoylmethyl-1,4-diazabicyclo[2,2,2]octanediium-1-yl)methyl-1,2,3,6-tetrahydropyridinylthiocarbonylthio]carbapenem, 14a showing greater than 2-fold better anti-MRSA activity in a mouse infection model and 3-fold better DHP-I susceptibility as compared with BO-3482 (1).

Animals↗
PubMed2001

Prognostic evaluation for squamous cell carcinomas of the lower thoracic esophagus treated with three-field lymph node dissection.

OBJECTIVE: The efficacy of esophagectomy with three-field lymph node dissection in surgical treatment for patients with squamous cell carcinomas of the lower thoracic esophagus remains controversial. This report documents the outcomes of this surgical procedure for a large series. METHODS: From February 1986 to November 1998, 437 patients with squamous cell carcinomas of the thoracic esophagus underwent transthoracic esophagectomy with three-field lymph node dissection. One hundred and sixteen of these had cancer of the lower thoracic esophagus. To avoid the influence of adjuvant therapy on survival, 20 who also received radiation and/or chemotherapy were excluded, leaving 96 patients who were retrospectively analyzed. RESULTS: The operative morbidity, and 30-day and in-hospital mortality rates were 62, 0, and 3%, respectively. The overall 1-, 3-, and 5-year survival rates were 89, 65, and 59%, with a median survival of 76 months. In those with lymph node metastases (66% of cases), the values were 87, 56, and 48%, as compared with 94, 84, and 79%, respectively (P=0.005) for patients without lymph node metastasis. Factors significantly influencing the overall survival rates were patient age (> or = 65 vs. <65), clinical N status (cN1 vs. cN0), clinical M status (cM1 vs. cM0), longitudinal tumor length of resected specimen (> or =5 vs. <5 cm), pathologic T status (pT3 vs. pT1, 2), pathologic N status (pN1 vs. pN0), lymphatic invasion (positive vs. negative), vascular invasion (positive vs. negative) and intramural metastasis (present vs. absent). Independent prognostic factors for survival determined by multivariate analysis were pathologic T status (P=0.02), pathologic N status (P=0.03), and presence of intramural metastasis (P=0.04). Additional pathologic M1 status, cervical or celiac lymph node metastasis, was without significant influence. CONCLUSIONS: Patients with pathologic T3 tumors with both pathologic N1 status and the presence of intramural metastasis in the lower thoracic esophagus had a poor prognosis. Cervical or celiac lymph node metastasis in patients with carcinomas of the lower thoracic esophagus should be distinguished from pathologic M1 status in the UICC-TNM staging system.

Adult↗
PubMed2001

Doppler ultrasonographic identification of the critical segmental artery for spinal cord protection.

OBJECTIVE: The purpose of this study is to evaluate the possibility of identifying critical segmental arteries (CSAs) based on Doppler ultrasonographic hemodynamics. METHODS: In 18 mongrel dogs, the descending aorta was scanned directly with a 5-MHz linear probe through left thoracotomies and the flow velocities in segmental arteries were measured by pulsed Doppler. The aorta was cross-clamped between Th13 and L1, and flow velocity changes were recorded. According to flow increases, segmental arteries were divided into three groups: arteries with the largest flow increase (L-arteries), arteries with the smallest increase (S-arteries) and other arteries (O-arteries). Animals were divided into three groups. One aortic segment including an L-artery or an S-artery was perfused via a temporary shunt during 30-min aortic cross-clamping distal to the left subclavian artery (Group L or Group S) and neurological outcomes were compared with those of animals without shunting (Group N) after 24 and 48 h. RESULTS: L-arteries had significantly larger flow increases than S- and O-arteries (74.3+/-33.8, 20.4+/-9.8 and 33.3+/-17.8 cm/s, P<0.01). In Group N, five of the six animals were completely paraplegic (Tarlov Grade 0) and the other was Grade 1. In Group S, four animals were Grade 4 and two were Grade 0 after 24h. However, two animals showed delayed paraplegia. Therefore, four animals were Grade 0 and two were Grade 4 after 48 h. All animals in Group L were neurologically normal (Grade 4) at both after 24h (vs. Group N, P=0.0013) and 48 h (vs. Group N, P=0.0013; vs. Group S, P=0.019). CONCLUSIONS: Flow responses to aortic cross-clamping differed among segmental arteries and selective perfusion of L-arteries completely prevented paraplegia. Therefore, L-arteries were considered to be CSAs. Hemodynamic measurement of segmental arterial flow using Doppler ultrasonography could be clinically useful for spinal cord protection during thoracoabdominal aortic surgery.

Animals↗
PubMed2001

Kinetics of Trypanosoma cruzi infection in guinea-pigs, with special reference to the involvement of epidermal Langerhans' cells in the induction of immunity.

Several studies have confirmed that epidermal Langerhans' cells (LC) play a central role in the induction of skin-related immunological events. In order to assess the role of LC in Chagas' disease, guinea-pigs were infected intradermally with Trypanosoma cruzi, sacrificed at different time-points, and their tissues were processed for routine histology, electron microscopy and immunohistochemistry. Parasitaemia was observed earliest at day 6 p.i. with 2 peaks at days 9 and 28, and disappeared on day 56 p.i. Parasite-specific serum IgG and IgM were first detected on day 12 p.i. The level of IgG gradually increased by day 84 p.i. All the infected guinea-pigs showed significant alterations in the distribution and morphology of epidermal LC during parasitacmia. The number of LC had significantly decreased in the epidermis by day 3 p.i., only returning to normal levels by day 56 p.i., although the number of LC in the underlying dermis increased concomitantly. Parasites were carried to the regional lymph node, where clustering of parasite-laden dendritic cells (DC) with lymphocytes was seen by electron microscopy. This evidence suggests that LC might be involved in antigen presentation in Chagas' disease.

Animals↗
PubMed2001

Quantitative relationship between myocardial concentration of tacrolimus and QT prolongation in guinea pigs: pharmacokinetic/pharmacodynamic model incorporating a site of adverse effect.

Clinical cases have been reported of tacrolimus (FK506)-induced QT prolongation. We have previously demonstrated sustained QT prolongation by FK506 in guinea pigs. Herein, we aimed to conduct a pharmacokinetic/pharmacodynamic (PK/PD) analysis of FK506, using a model involving the myocardial compartment. The pharmacokinetics of FK506 and its effects on QTc intervals were investigated in guinea pigs. In the pharmacokinetic study, whole blood and ventricular FK506 concentrations were analyzed, using a 4-compartment model during and after intravenous infusion of FK506 (0.01 or 0.1 mg/hr/kg). Subsequently, the concentration-response relationship between ventricular FK506 concentration and change in QTc interval was analyzed, using the maximal effect (Emax) model. Pharmacokinetic profiles of FK506 showed a delayed distribution of FK506 into the ventricle. Furthermore, the observed QT prolongation paralleled the ventricular FK506 concentrations, with no lag-time between the two. The Emax model successfully described the relationship between changes in QTc interval and ventricular FK506 concentrations. In conclusion, the PK/PD model where the myocardial drug concentration of FK506 was linked with its adverse effect could describe, for the first time, the anti-clockwise hysteresis observed in the relationship between blood FK506 concentration and QTprolongation. Such a hysteresis pattern for QTprolongation might be caused, therefore, mainly by the delayed disposition of FK506 to ventricular myocytes.

Animals↗
PubMed2001

Superoxide dismutase in senescence-accelerated mouse retina.

To examine the relationship between retinal ageing and superoxide dismutase, we studied the dismutase, with immunohistochemistry and immunoquantitative analysis, in the retina of senescence-accelerated mice P8/Ta (SAMP8/Ta) 3 and 12 months after birth. Accelerated senescence-resistant mice R1TA (SAMR1TA), which show no acceleration of senescence, were used as controls. In SAMP8/Ta, copper-zinc superoxide dismutase and manganese superoxide dismutase immunoreactivity in the photoreceptor inner segments, the outer nuclear layer and the inner nuclear layer increased earlier than in the controls. The increase in both superoxide dismutases with age occurred not only in SAMP8/Ta retinas but also in the controls. In conclusion, we propose the possibility that SAMP8/Ta undergo deterioration not only of learning and memory but also acceleration of senescence in the retina. The dismutases also appear to increase with normal ageing in the retina.

Aging↗
PubMed2001

Distinctive expression of extracellular matrix molecules at mRNA and protein levels during formation of cellular and acellular cementum in the rat.

Little is known about differential expression of extracellular matrices secreted by cementoblasts between cellular and acellular cementum. We hypothesize that cementoblasts lining acellular cementum express extracellular matrix genes differently from those lining cellular cementum, thereby forming two distinct types of extracellular matrices. To test this hypothesis, we investigated spatial and temporal gene expression of selected extracellular matrix molecules, that is type I collagen, bone sialoprotein, osteocalcin and osteopontin, during formation of both cellular and acellular cementum using in situ hybridization. In addition, their extracellularly deposited and accumulated proteins were examined immunohistochemically. The mRNA transcripts of pro-alpha1 (I) collagen were primarily localized in cementoblasts of cellular cementum and cementocytes, while those of bone sialoprotein were predominantly seen in cementoblasts lining acellular cementum. In contrast, osteocalcin was expressed by both types of cementoblasts and cementocytes and so was osteopontin but only transiently. Our immunohistochemical examination revealed that translated proteins were localized extracellularly where the genes had been expressed intracellularly. The present study demonstrated the distinctive expression of genes and proteins of the extracellular matrix molecules between cellular and acellular cementum.

Animals↗
PubMed2001

Comparison of oligosaccharides derived from salivary mucin of Japanese secretor and non-secretor individuals of blood group type-A.

Comparison of oligosaccharide components derived from salivary mucin was performed between secretor and non-secretor individuals. Salivary mucin was collected from four secretors and three non-secretors having blood group type-A. Compositional analysis showed that the contents of galactose and N-acetylglucosamine in the non-secretor were higher than those in the secretor. The O-linked oligosaccharides obtained by treatment with alkaline borohydride were separated by gel filtration using Sephadex G-50. The results indicated that the size of the type-A active oligosaccharides from the secretor was similar to or smaller than that of the non-secretor. Ion-exchange chromatography showed that the secretors had strong type-A activities in both the neutral and acidic fractions but the non-secretors showed type-A activity mainly in the neutral fraction. These results suggest that compositional differences in blood group substances exist between secretors and non-secretors.

ABO Blood-Group System↗
PubMed2001

Relationship between total and regional bone mineral density and menopausal state, body composition and life style factors in overweight Japanese women.

OBJECTIVE: To investigate whether menopausal state, body composition and lifestyle factors influence total and regional bone mineral density in overweight Japanese women. DESIGN: Cross-sectional study of women who were recruited to the weight reduction program held at community-based health promotion center in Tokyo area. SUBJECTS: A total of 178 women with a mean age of 48 y old (20-69 y) with a clear menstrual history and BMI over 24. MEASUREMENTS: Total, regional and lumbar spine bone mineral density (BMD) and body composition were measured using DXA (Lunar). Menstrual history was taken by a questionnaire and walking steps per day and energy intake were measured. Physical fitness was assessed by cardio-respiratory fitness and leg extension power. Subjects were divided into pre-menopausal and post-menopausal groups. RESULTS: Pre-menopausal group had significantly higher total body BMD as well as regional BMD than post-menopausal group. However, no differences in BMI, percentage fat and fat mass (FM) were seen between the two groups. The multiple regression analysis stepwise method revealed that total and regional BMD correlated with menopausal state and total FM independently. Total and regional BMD did not correlate with total non-fat soft tissue mass (NFSM), energy intake, walking steps or physical fitness levels. Trunk and lower extremities BMD correlated with corresponding regional FM and NFSM, and upper extremities BMD correlated with only corresponding body part NFSM after adjusting menopausal state. CONCLUSION: Total and regional BMD had strong negative correlation with menopausal state rather than total FM in overweight Japanese women. Weight-bearing site BMD correlated with corresponding body part FM and NFSM and non-weight bearing site BMD only correlated with corresponding body part NFSM after adjusting for menopausal state.

Absorptiometry, Photon↗
PubMed2001

Successive non-suppressed ion chromatography of common cations and anions using dual columns with single eluent.

A successive non-suppressed ion chromatography (IC) system for the determination of common cations (Na+, K+, Mg2+, Ca2+) and anions (Cl-, Br-, NO3-, SO4(2-)) was developed, using two separation columns and a single eluent. 5-Sulfoisophthalic acid eluent was very suitable for such separations with a commercially available cation-exchange column for the mono- and di-valent cations and with an ODS column coated with cetyltrimethylammonium for the anions. Both cations and anions were detected with conductimetrically high sensitivity without any suppressor. After injecting an aliquot of sample solution, the solvent front from the cation-exchange column, including most of the anionic species, was firstly accumulated into the additional 2 ml accumulation loop for 60 s, while the cation IC was performed. Subsequently, the accumulated fraction was introduced into the anion-exchange column and chromatographed. Relative standard deviations (RSDs) of retention times and conductimetric area responses for common cations were within 6% and within 4%, respectively. The linear relationships between molar concentration and detector response ranged from 0.01 to 1.00 mM with r2 of 0.9994 for Na+, 0.9992 for K+, 0.9993 for Mg2+, and 0.9988 for Ca2+. The successive anion IC through the accumulating process was also quantitative, with 95% recovery or over for each analyte. The linear ranges were between 0.01 and 1.00 mM with r2 of 0.9996 for Cl-, 0.9997 for Br-, 0.9993 for NO3-, and 0.9984 for SO4(2-). The method was applied to the determination of common cations and anions in several mineral waters and a hot spring water.

Journal Article↗