Biomedical subjects

Tetsu Watanabe

Publications and source records attributed to Tetsu Watanabe.

At least 19 recordsLinked to original sources

PubMed2007

Bone marrow-derived cells express matrix metalloproteinases and contribute to regression of liver fibrosis in mice.

UNLABELLED: Liver fibrosis is usually progressive, but it can occasionally be reversible if the causative agents are adequately removed or if patients are treated effectively. However, molecular mechanisms responsible for this reversibility of liver fibrosis have been poorly understood. To reveal the contribution of bone marrow (BM)-derived cells to the spontaneous regression of liver fibrosis, mice were treated with repeated carbon tetrachloride injections after hematopoietic reconstitution with enhanced green fluorescent protein (EGFP)-expressing BM cells. The distribution and characteristics of EGFP-positive (EGFP(+)) cells present in fibrotic liver tissue were examined at different time points after cessation of carbon tetrachloride intoxication. A large number of EGFP(+) cells were observed in liver tissue at peak fibrosis, which decreased during the recovery from liver fibrosis. Some of them, as well as EGFP-negative (EGFP(-)) liver resident cells, expressed matrix metalloproteinase (MMP)-13 and MMP-9. Whereas MMP-13 was transiently expressed mainly in the cells clustering in the periportal areas, MMP-9 expression and enzymatic activity were detected over the resolution process in several different kinds of cells located in the portal areas and along the fibrous septa. Therapeutic recruitment of BM cells by granulocyte colony-stimulating factor (G-CSF) treatment significantly enhanced migration of BM-derived cells into fibrotic liver and accelerated the regression of liver fibrosis. Experiments using transgenic mice overexpressing hepatocyte growth factor (HGF) indicated that G-CSF and HGF synergistically increased MMP-9 expression along the fibrous septa. CONCLUSION: Autologous BM cells contribute to the spontaneous regression of liver fibrosis, and their therapeutic derivation could be a new treatment strategy for intractable liver fibrosis.

Animals↗

PubMed2006

All-trans retinoic acid down-regulates human albumin gene expression through the induction of C/EBPbeta-LIP.

ATRA (all-trans retinoic acid), which is a major bioactive metabolite of vitamin A and a potent regulator of development and differentiation, mediates down-regulation of the human albumin gene. However, the mechanism of ATRA-mediated down-regulation is not well understood. In the present study, deletion analysis and luciferase assays demonstrate that ATRA causes a marked decrease in the activity of the albumin promoter, the region between nt -367 and -167 from the transcription start site, where C/EBP (CCAAT/enhancer-binding protein)-binding sites are tightly packed, is indispensable for ATRA-mediated down-regulation. ChIP (chromatin immunoprecipitation) assays revealed that in vivo binding of C/EBPalpha to the region markedly decreases upon incubation with ATRA, whereas ATRA treatment marginally increases the recruitment of C/EBPbeta. We found that ATRA has the ability to differentially and directly induce expression of a truncated isoform of C/EBPbeta, which is an LIP (liver-enriched transcriptional inhibitory protein) that lacks a transactivation domain, and to increase the binding activity of C/EBPbeta-LIP to its response element. Overexpression of C/EBPbeta-LIP negatively regulates the endogenous expression of albumin, as well as the activity of the albumin promoter induced by C/EBP transactivators such as C/EBPalpha and full-length C/EBPbeta. In conclusion, we propose a novel model for down-regulation of the albumin gene, in which ATRA triggers an increase in the translation of C/EBPbeta-LIP that antagonizes C/EBP transactivators by interacting with their binding sites in the albumin promoter.

Albumins↗

PubMed2006

Hyperuricemia associated with high cardiac event rates in the elderly with chronic heart failure.

OBJECTIVES: Congestive heart failure (CHF) is the major cause of death and hospitalization in the elderly population. Simple markers that can be measured anywhere at low cost are necessary to identify patients at high risk. Recent studies have reported that hyperuricemia is a prognostic marker for CHF. However, it is not yet known whether serum levels of uric acid may provide prognostic information in the elderly population. Therefore, this study tried to identify the clinical characteristics of elderly CHF patients (+/-70 years) in our institution and to evaluate whether uric acid levels can effectively estimate the prognosis for elderly CHF patients. METHODS AND RESULTS: Uric acid levels were analyzed in 247 CHF patients, and patients were followed up for 451 +/- 235 days (mean +/- SD). Elderly CHF patients aged > or =70 years (123 patients) had higher rate of hypertension, lower current smoking rate and higher uric acid levels than those aged < 70 years (124 patients). There were 72 cardiac events including cardiac deaths and readmissions for worsening CHF. Multivariate analysis with the Cox proportional hazard model showed that uric acid was the only independent predictor of cardiac events (hazard ratio 1.544, 95% confidence interval 1.215-2.582, p < 0.0001) in the elderly with CHF. The highest quartile of uric acid level was associated with the highest risk of cardiac events (a 4.45-fold compared to the lowest quartile). Kaplan-Meier analysis revealed that uric acid levels effectively risk stratified elderly CHF patients for cardiac events. CONCLUSIONS: These findings suggest that measurement of uric acid levels in elderly CHF patients may add valuable prognostic information to predict cardiac events.

Aged↗

PubMed2005

Losartan metabolite EXP3179 activates Akt and endothelial nitric oxide synthase via vascular endothelial growth factor receptor-2 in endothelial cells: angiotensin II type 1 receptor-independent effects of EXP3179.

BACKGROUND: Recent studies suggest that angiotensin type 1 receptor (AT1R) blockers have vascular protective effects beyond blood pressure lowering. Because of the importance of endothelial nitric oxide synthase (eNOS) in vascular and platelet function, we hypothesized that losartan and its metabolites would stimulate eNOS and its upstream activators Akt and phosphatidylinositol 3-kinase (PI3K). METHODS AND RESULTS: Losartan is metabolized into EXP3174 (AT1R-blocking metabolite) and EXP3179 (no AT1R-blocking properties). Treatment of endothelial cells (ECs) with losartan and both metabolites stimulated phosphorylation of Akt and eNOS in the absence of angiotensin II. However, the magnitude for EXP3179 was much greater than EXP3174, and the EC50 was significantly lower (-logEC50, 8.2+/-0.1 versus 5.4+/-0.2 mol/L), suggesting an AT1R-independent effect. Inhibiting PI3K or vascular endothelial growth factor receptor 2 (VEGFR2) tyrosine phosphorylation abrogated EXP3179-induced eNOS phosphorylation. In endothelium of intact rat aorta, EXP3179 also stimulated Akt and eNOS phosphorylation. VEGFR2 activation was shown to be calcium and Src family kinase dependent by use of specific drug inhibitors and dominant negative kinase transfection. EXP3179 significantly inhibited tumor necrosis factor alpha-induced apoptosis by approximately 60% (from 30.1+/-5.8% to 12.2+/-2.0% TUNEL-positive cells), which was abolished by pretreatment with the PI3K inhibitor LY294002. Cleaved caspase-3 was suppressed by 48% with EXP3179. CONCLUSIONS: The losartan metabolite EXP3179 stimulates eNOS phosphorylation and suppresses tumor necrosis factor alpha-induced EC apoptosis by activating the VEGFR2/PI3K/Akt pathway.

Angiotensin II Type 1 Receptor Blockers↗

PubMed2005

[Development of three-dimensional kinematic analysis system for artificial knee implants using X-ray fluoroscopic imaging].

To achieve quantitative assessment of 3D dynamic motion of artificial knee implants under clinical conditions, we developed a 3D kinematic analysis system using X-ray fluoroscopic imaging. The 3D pose-estimation technique for knee implants was built on a 2D/3D registration algorithm, which determines the spatial pose for each femoral and tibial component from the knee implant contours and computer-assisted design (CAD) models of the implant. In order to validate the accuracy of the 3D pose estimation and the system, computer simulation and in vitro tests were performed using images of knee implants taken in 10 different poses with respect to X-ray focus. Computer simulation tests showed that the root mean square errors (RMSE) for all variables were less than 1.0 mm 1.0 degrees. In vitro tests showed that the RMSE for translation perpendicular to the X-ray image plane was about 1.5 mm, while the accuracy of the remaining two translational and three rotational variables was found to be sufficient for analyzing knee kinematics. Computation time in 3D pose estimation was then obtained in less than 30 seconds for each frame. In clinical application, dynamic movement in deep knee bending was quantitatively analyzed, and the feasibility and effectiveness of the system was demonstrated.

Algorithms↗

PubMed2005

Angiotensin II and the endothelium: diverse signals and effects.

The initial view of the renin-angiotensin system focused on the role of angiotensin II as a hormone involved in blood pressure control, based on its role in renal salt and water regulation, as well as central nervous system (thirst) and vascular smooth muscle tone. Subsequent data showed a role for angiotensin II in long-term effects on cardiovascular structure, including cardiac hypertrophy and vascular remodeling. Importantly, recent human studies with angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers have demonstrated exciting clinical benefits including decreases in incidence of stroke, diabetes, and end-stage renal disease that suggest important new mechanisms of action. In this review, we focus on new roles for the renin-angiotensin system in the endothelium based on the concepts of diverse signals and effects mediated by multiple angiotensin I- and angiotensin II-derived peptides, multiple angiotensin metabolizing enzymes, multiple receptors, and vascular bed-specific intracellular signals.

Angiotensin II↗

PubMed2005

C-reactive protein elevation predicts the occurrence of atrial structural remodeling in patients with paroxysmal atrial fibrillation.

It has been poorly understood whether inflammation may contribute to atrial structural remodeling and increase the propensity for atrial fibrillation (AF) to persist. We investigated the relationship between C-reactive protein (CRP) elevation and the development of atrial remodeling in AF. The study population comprised 50 consecutive paroxysmal AF (PAF) patients and 50 control patients without AF. All patients underwent echocardiography, and high-sensitivity CRP was routinely measured. C-Reactive protein was significantly higher in the patients with PAF than control patients (0.231+/-0.176 mg/dl vs 0.055+/-0.041 mg/dl, P<0.001). Other predictors of elevated CRP included left ventricular mass (P<0.05), left ventricular end-systolic diameter (P<0.05), and left atrial (LA) diameter (P<0.001). In a multivariate analysis, only CRP and LA diameter were independent predictors of PAF. Elevated CRP levels correlated with LA diameter (r=0.489, P<0.001). Left atrial diameter was increased in PAF patients compared with control patients (P<0.001). We found that a longer duration of AF is associated with higher CRP levels and a larger LA diameter (duration <30 days: CRP 0.166+/-0.139 mg/dl, LA diameter 38.4+/-8.0 mm; duration >30 days: CRP 0.345+/-0.181 mg/dl, LA diameter 45.6+/-6.6 mm; P<0.001). In conclusion, longer AF duration is associated with CRP elevation and atrial structural remodeling, as approximated by larger LA diameter. However, CRP elevation, while correlating with LA diameter, was not an independent predictor of atrial structural remodeling. Thus, it remains unclear whether CRP and the inflammatory state are contributory to LA remodeling or whether LA remodeling or AF induces elevation in CRP and inflammation.

Aged↗

PubMed2005

Visualization of femorotibial contact in total knee arthroplasty using X-ray fluoroscopy.

The purpose of this study was to build a visualization technique of the femorotibial contact in fixed-bearing total knee arthroplasty (TKA) using X-ray fluoroscopy, and to apply this technique to a TKA patient during dynamic motion. In vivo kinametcis of the metallic knee implant was determined using a 2D/3D registration technique, which uses computer assisted design (CAD) model of the implant to estimate the 3D pose of radiopaque metallic femoral and tibial components from a single-plane fluoroscopic image. In fixed-bearing TKA, a 3D pose of radiolucent tibial polyethylene insert can be determined from the estimated pose of the tibial component. To visualize femorotibial contact, the proximity between surfaces of femoral component and tibial insert was calculated, and mapped onto the insert surface model. For the clinical application, dynamic states of contact on the tibial insert were observed including axial rotation and unilateral loading during knee flexion, and post-cam contact of posterior stabilized TKA. The present technique provided us new information and enabled us to better understand the relationship between in vivo knee kinematics and articular shape of the implant.

Arthroplasty, Replacement, Knee↗

PubMed2005

Cell type-specific intervention of transforming growth factor beta/Smad signaling suppresses collagen gene expression and hepatic fibrosis in mice.

BACKGROUND & AIMS: Transforming growth factor beta and its intracellular mediators, Smad proteins, play important roles in stimulating collagen gene transcription and, thus, could be the targets for treating hepatic fibrosis. However, intervention of transforming growth factor beta/Smad signaling affects physiological signal transduction as well and may cause serious adverse effects on clinical application. Here we have attempted to suppress hepatic fibrosis by expressing a transforming growth factor beta/Smad antagonist selectively in collagen-producing cells only in the fibrotic liver. METHODS: Recombinant adenoviruses expressing either green fluorescent protein or a transforming growth factor beta/Smad signal repressor, YB-1, were injected into mice untreated or treated with carbon tetrachloride. Green fluorescent protein expression was analyzed under a confocal laser scanning microscope. Antifibrotic effects of YB-1 overexpression were examined by luciferase assays and histological examination with transgenic reporter mice. RESULTS: When the CAG expression unit was used as a control, green fluorescent protein was strongly expressed in a large number of hepatocytes in both normal and carbon tetrachloride-treated liver. In contrast, green fluorescent protein expression driven by a tissue-specific enhancer of the mouse alpha2(I) collagen gene ( COL1A2 ) was detected in activated hepatic stellate cells in carbon tetrachloride-induced fibrotic liver, but not in untreated normal liver. No green fluorescent protein fluorescence was observed in any other organs when the COL1A2 enhancer was used. Adenovirus-mediated YB-1 expression under the control of the COL1A2 enhancer significantly decreased COL1A2 promoter activity after carbon tetrachloride injection and subsequently suppressed the progression of hepatic fibrosis. CONCLUSIONS: These results validate a new concept of the therapy for hepatic fibrosis to achieve cell type-specific gene expression only in the fibrotic liver, with little damage to other organs.

Adenoviridae↗

PubMed2005

Metabolic syndrome from the view point of public health: with special reference to nonalcoholic fatty liver disease.

Changes in human behavior and lifestyle over the last century have resulted in a dramatic increase in the incidence of obesity, type 2 diabetes, and the metabolic syndrome. Differences in the reported overall prevalence of the metabolic syndrome, which is generally in the range of 10-30% depend on the diagnostic criteria and subjects of the study. Recently, Japanese criteria for diagnosis of the metabolic syndrome were defined. With these criteria, presence of visceral obesity is essential for the diagnosis and is simply determined by measurement of waist circumference. Reflecting a dramatic increase in the incidence of obesity and type 2 diabetes, the incidence of the metabolic syndrome is increasing in Japan as well as in Western countries, regardless of the criteria applied. Recently, the number of workers with elevated liver enzymes, in whom virus hepatitis, alcoholic liver disease, drug induced hepatitis, autoimmune hepatitis, and iron overload were ruled out as causal agents, has also be found to be increasing at workplace health checkups. Most of such workers have components of the metabolic syndrome and the presence of steatosis in the liver, this pathologic condition now being termed nonalcoholic fatty liver disease (NAFLD). In this review, we describe the relationship between NAFLD and the metabolic syndrome.

Adult↗

PubMed2005

Change of components of the metabolic syndrome in a workers' health checkup after five years--relation with elevated liver enzymes, gene polymorphisms for ALDH 2, beta3-AR and lifestyle.

We previously reported that the prevalence of elevated alanine aminotransferase (ALT) increases with accumulation of metabolic syndrome components, and a greater degree of involvement of aldehyde dehydrogenase 2 (ALDH2) than beta3-adrenergic receptor gene (beta3-AR) polymorphisms. The present study was designed to clarify the effect of aging, lifestyle and the two gene polymorphisms on the relationship between 4 components of the metabolic syndrome (obesity, hypertension, dyslipidemia and impaired glucose tolerance) and elevated ALT values in a subset of 73 out of 148 male workers who were 35 years of age in the baseline study and 40 years old in the present study. Study subjects completed questionnaires about drinking and smoking habits, and underwent urinalysis, physical examination and peripheral blood tests, blood chemistry, electrocardiogram and chest X-rays each year as required by Japanese law. Information from the questionnaires and physical examinations, including liver function tests, were compared with previously reported ALDH2 and beta3-AR genotypes for the 73 workers. Of the 73 workers studied, 14 (19%) demonstrated decrease in metabolic syndrome components, 39 (53%) demonstrated no change, and 20 (27%) demonstrated an increase. Ten workers (14%) showed liver dysfunction at age 35 and 20 workers (27%) at age 40. Fourteen workers were newly diagnosed as having liver dysfunction at their 40-year checkup, thus being associated with the BMI and an active ALDH2 genotype. Accumulation of components of the metabolic syndrome were associated with the presence of liver dysfunction at 35 years. In conclusion, these findings indicate that ALDH2 genotyping as well as lifestyle habits may be important factors in causing metabolic syndrome with liver dysfunction.

Adult↗

PubMed2005

Association of change in the type of job with prevalence of components of the metabolic syndrome-special reference to job stress.

OBJECTIVE: It is well established that job stress is a leading cause of cardiovascular disease. The relationship with the metabolic syndrome, however, has received only limited attention. The present study was designed to investigate associations between change of the type of job and the prevalence of metabolic syndrome components from the aspect of on-the-job stress and alteration in life style. METHODS: Thirty-six male workers of the manufacturing department were transferred to the carsales department at the same automobile company in 1992 to 1993. These same workers were transferred back to the manufacturing department after two years. We compared the first health-check data before the transfer in 1992 (Term A), a second set of data two years after transfer in 1994-95 (Term B) and a third set of data two years following transfer back to the manufacturing department in 1996-1998 (Term C). The workers were requested to provide information about drinking and smoking habits, and answer Karasek's questionnaire and a simple stress questionnaire in order to clarify the possibility of job stress in occurrence of the metabolic syndrome, defined in terms of obesity, hypertension, dyslipidemia, and impaired glucose tolerance as components. RESULTS: Five workers had two or more components of the metabolic syndrome before the transfer to the car-sales department (Group I). One demonstrated improvement, three no change, and one increase in symptoms from A to B. Seven workers had more than two components after the transfer to car-sales department (Group II), and six of them exhibited decrease two years following transfer back to the manufacturing department. Five of them also showed elevated liver enzymes in serum with the appearance of the components, and three of them demonstrated recover. Three workers had two components of the metabolic syndrome only at time point C (Group III), while the remaining 21 workers had 0 to one component throughout the observation period (Group IV). Amount of drinking and smoking increased significantly when working in the sales department but these items returned to the previous values after rejoining manufacturing, though differences were not observed between workers with (Group II) and without (Group IV) components of the metabolic syndrome. Body mass index (BMI) and alanine aminotransferase (ALT) increased significantly when workers moved to the sales department and that was significant in Group II as compared to Group IV. Three components of Karasek's JCQ changed significantly during job transfer, though differences were not observed between the workers with (Group II) and without (Group IV) components of the metabolic syndrome. Logistic regression analysis with age, lifestyle, Karasek's JCQ, and ALT revealed that elevation of ALT value was associated with having two or more components of metabolic syndrome, while hours of sleep demonstrated an inverse association. CONCLUSION: Elevated ALT and reduction of sleep hours may be associated with development of the metabolic syndrome in workers who change their type of job.

Adult↗

PubMed2004

c-Jun NH2-terminal kinase pathway is involved in constitutive matrix metalloproteinase-1 expression in a hepatocellular carcinoma-derived cell line.

Transcription factor c-Jun serves for cellular proliferation, survival, differentiation and transformation and is recognized as an important factor in cancer development, including hepatocellular carcinoma (HCC). The purpose of present study is to determine the involvement of c-Jun in matrix metalloproteinase-1 (MMP-1) expression, which is previously reported by us to be expressed only in the early stage of human HCC showing stromal invasion. Of 5 human HCC cell lines examined, only HLE cells revealed mRNA and protein expression as well as enzymatic activity of MMP-1. Transient transfection of an MMP-1 promoter/luciferase construct (including 4.4 kb full promoter region) into HLE and HCC-T cells (MMP-1 nonproducer) showed that high promoter activity was observed only in HLE cells without inducers, and that this promoter activity was still observed when a shorter 0.6 kb proximal promoter construct was transfected. The 0.6 kb promoter region contained 3 AP-1 sites, and c-jun mRNA was constitutively expressed in HLE cells without inducers. Furthermore, phosphorylated c-Jun and c-Jun NH2-terminal kinase (JNK) were detected in HLE cells. Promoter activity of the 0.6 kb construct was suppressed with SP600125, a potent inhibitor of JNK, but not with PD98059 and SB203580, potent inhibitors of MEK1/2 and p38, respectively. The inhibitory effect of SP600125 was also observed at protein expression level and in enzymatic activity of MMP-1. Taken together, this study suggests that the JNK pathway is involved in the expression of MMP-1 in HCC cells and may represent a new functional role of c-Jun for HCC development.

Carcinoma, Hepatocellular↗

PubMed2004

In vivo kinematics of mobile-bearing knee arthroplasty in deep knee bending motion.

The current study aimed to analyze kinematics during deep knee bending motion by subjects with fully congruent mobile-bearing total knee arthroplasties allowing axial rotation and anteroposterior (AP) gliding. Twelve subjects were implanted with Dual Bearing Knee prostheses (DBK, slot type: Finsbury Orthopaedics, Surrey, UK). These implants include a mobile-bearing insert that is fully congruent with the femoral component throughout flexion and allows axial rotation and limited AP translation. Sequential fluoroscopic images were taken in the sagittal plane during loaded knee bending motion. In vivo kinematics were analyzed using a two- to three-dimensional registration technique, which uses computer-assisted design models to reproduce the spatial position of femoral and tibial components from single-view fluoroscopic images. The average femoral component demonstrated 13.4 degrees external axial rotation for 0-120 degrees flexion. On average, the medial condyle moved anteriorly 6.2 mm for 0-100 degrees flexion, then posteriorly 4.0 mm for 100-120 degrees flexion. On average, the lateral condyle moved anteriorly 1.0 mm for 0-40 degrees flexion, then posteriorly 8.7 mm for 40-120 degrees flexion. The typical subject exhibited a lateral pivot pattern from extension to 60 degrees flexion and a central pivot pattern from 60 degrees to 100 degrees flexion, patterns that are not usually observed in normal knees. Subsequently from 100 degrees to 120 degrees flexion, a rollback pattern was reproduced in which bilateral condyles moved backward.

Aged↗

PubMed2004

Adhesion of the subacromial bursa may cause subacromial impingement in patients with rotator cuff tears: pressure measurements in 18 patients.

In order to determine whether adhesion of the subacromial bursa leads to impingement, we measured the subacromial contact pressures before and after release of adhesion of this bursa. 18 shoulders with cuff tears and adhesion of the subacromial bursa were evaluated in 8 male and 10 female patients, of mean age 62 (53-71) years and who had no particular limitation of shoulder motion. We recorded subacromial pressures using a very sensitive film inserted under the acromion during surgery. In passive scapular plane elevation (scaption) at 100 degrees, the mean subacromial contact pressure and area declined from 1.43 (SD 0.23) MPa before release to 1.14 (SD 0.35) MPa after release (p < 0.001), and from 163 (SD 81) mm2 before release to 80 (SD 46) mm2 after release (p < 0.001), respectively. We suggest that adhesion of the subacromial bursa increases impingement between the acromion and the insertion of rotator cuff tendons.

Acromion↗

PubMed2004

Improvement of depth position in 2-D/3-D registration of knee implants using single-plane fluoroscopy.

Two-dimensional (2-D)/three-dimensional (3-D) registration techniques using single-plane fluoroscopy are highly important for analyzing 3-D kinematics in applications such as total knee arthroplasty (TKA) implants. The accuracy of single-plane fluoroscopy-based techniques in the determination of translation perpendicular to the image plane (depth position), however, is relatively poor because a change in the depth position causes only small changes in the 2-D silhouette. Accuracies achieved in depth position using conventional 2-D/3-D registration techniques are insufficient for clinical applications. Therefore, we propose a technique for improving the accuracy of depth position determination in order to develop a system for analyzing knee kinematics over the full six degrees of freedom (6 DOF) using single-plane fluoroscopy. In preliminary experiments, the behaviors of errors for each free variable were quantified as evaluation curves by examining changes in cost function with variations in the free variable. The evaluation curve for depth position was more jagged, and the curve peak less pointy, compared to the evaluation curves of the other five variables, and the curve was found to behave differently. Depth position is therefore optimized independently of the other variables, using an approximate evaluation curve of depth position prepared after initial registration. Accuracy of the proposed technique was evaluated by computer simulation and in vitro tests, with validation of absolute position and orientation performed for each knee component. In computer simulation tests, root-mean-square error (RMSE) in depth position was improved from 2.6 mm (conventional) to 0.9 mm (proposed), whereas for in vitro tests, RMSE improved from 3.2 mm to 1.4 mm. Accuracy of the estimation of the remaining two translational and three rotational variables was found to be almost the same as that obtained by conventional techniques. Results of in vivo tests are also described in which the possibility of full 6 DOF kinematic analysis of TKA implants is shown.

Algorithms↗

PubMed2004

Comparative socio-cultural analysis of smoking behavior and difficulty of quitting smoking in Japan and Thailand.

OBJECTIVE: Although education for smoking cessation is being conducted in Asian countries, the prevalence of smoking is still high. The present study was designed to clarify differences in the socio-cultural background in Japan and Thailand. METHODS: Cross-sectional study. The Japan survey was conducted in Kanagawa and the Thailand survey in Suphanburi. Questionnaires written in English were translated into each language. The subjects were out-patients of community hospitals (331 males and 353 females in Japan and 293 males and 288 females in Thailand). RESULTS: The prevalence of smoking was found to be higher in Thailand than in Japan for males but almost the same for females. A higher percentage of the subjects quit smoking in Japan than in Thailand. The motive for quitting smoking was "awareness of the harmful effects of smoking" in both countries, but "told by others to quit smoking" was also often encountered in Thailand. The method of quitting was most frequently "suppress the urge to smoke by will power" in both countries. Nicotine replacement therapy is not well known yet in either country. CONCLUSION: Smoking behavior was different although the difficulty of quitting smoking was common to both countries. The prevalence of smoking in younger males and females was established to be higher in Japan, and social and environmental regulations for quitting smoking were effective in Thailand. It suggests that such regulations should be made stricter in Japan. Enlightenment by providing knowledge may be particularly useful in Thailand.

Adult↗

PubMed2003

Total ankle replacement in rheumatoid arthritis.

We reviewed 21 patients with rheumatoid arthritis who had a total ankle replacement between 1984 and 2000. The average follow-up was 72 (15-169) months. Clinical results were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) score. At the latest review, three ankles had been revised. Two ankles were excellent, seven good, three fair, and 12 poor. Eleven patients with 13 ankles had residual pain, with radiographs showing a high incidence of radiolucent lines. Migration of the tibial component was seen in 13 ankles and collapse of talus in nine. Although clinical results were poor, patient satisfaction was not.

Adult↗