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Biomedical subjects

T Muto

Publications and source records attributed to T Muto.

At least 19 recordsLinked to original sources
PubMed2006

Surgical management of only hearing ears with positive indications.

Positive surgical indications for an only hearing ear were evaluated in order to improve patients' quality of life. Fifteen cases of surgery involving an only hearing ear over the past eight years were retrospectively reviewed. Of eight perforated chronic otitis media cases, seven underwent type one tympanoplasty and one underwent simple underlay myringoplasty regardless of otorrhoea at the time of surgery. Of six cholesteatoma cases, two received the canal wall up method and four received the canal wall down method. Ossiculoplasty was carefully performed in six cases. Hearing was improved in seven cases, whereas it remained unchanged in seven cases and deteriorated in one case. Of nine patients, two did not need a hearing aid after surgery. Five patients with severe combined hearing loss (>90 dB) were able to communicate with a hearing aid, alleviating their anxiety regarding hearing loss. Only hearing ears with chronic otitis media and cholesteatoma can be successfully treated by tympanoplasty with or without ossiculoplasty.

Adolescent↗
PubMed2006

Independent risk factors for chronic cyclosporine induced nephropathy in children with nephrotic syndrome.

BACKGROUND: Cyclosporine A (CsA) has been widely used in children with steroid dependent and steroid resistant nephrotic syndrome (NS) because of its efficacy in relieving these patients from systemic side effects of steroids. However, its long term use is controversial, since chronic CsA induced nephropathy (CsAN) may develop in a considerable number of patients. AIMS AND METHODS: In order to clarify the risk factors for the development of CsAN, the clinical characteristics of children with steroid dependent or steroid resistant NS taking CsA (target blood trough levels 50-150 ng/ml) for more than six months, managed at a single centre, were retrospectively analysed. RESULTS: Thirteen of 30 children (24 boys and 6 girls) taking CsA (mean duration 43 months, range 6-144) had CsAN defined as the presence of CsA associated arteriopathy with or without striped tubulointerstitial lesions. The multivariate analysis revealed that CsA treatment for more than 36 months and an age younger than 5 years at the start of CsA treatment were independent risk factors for the development of CsAN. The univariate analysis also showed that patients with CsAN had more frequent relapses during CsA treatment than those without CsAN. CONCLUSION: An alternative treatment should be seriously considered after a 36 month administration of CsA in order to prevent CsAN. Data also suggest that CsA treatment in children younger than 5 years should be avoided if possible.

Adolescent↗
PubMed2006

Clinical outcome of high segmental gastrectomy for early gastric cancer in the upper third of the stomach.

BACKGROUND: Reflux oesophagitis is commonly encountered in the surgical treatment of cancer of the upper third of the stomach. The aim of this study was to describe a novel surgical technique and evaluate the clinical outcome of high segmental gastrectomy for early-stage proximal gastric cancer. METHODS: Thirty consecutive patients with early gastric cancer located in the upper third of the stomach were included, of whom 12 underwent high segmental gastrectomy and 18 underwent proximal gastrectomy with jejunal interposition. The incidence of reflux oesophagitis and nutritional parameters were compared between the two groups at 1 year after operation. RESULTS: One patient had mild reflux symptoms and two had endoscopic evidence of oesophagitis 1 year after high segmental gastrectomy. Half of the patients who had proximal gastrectomy had reflux symptoms of varying severity and 14 had endoscopic evidence of oesophageal changes at 1 year after surgery. There were significant differences between groups in the incidence of reflux symptoms (P = 0.016) and endoscopically detected gastro-oesophagitis (P < 0.001). There were no adverse events in either group, and the survival rate after high segmental gastrectomy appeared favourable. CONCLUSION: Selected patients with early-stage proximal gastric cancer benefit from high segmental gastrectomy in terms of reduced reflex oesophagitis, without jeopardizing curability.

Aged↗
PubMed2005

Relationship between the pharyngeal airway space and craniofacial morphology, taking into account head posture.

This study assessed the relationship between craniofacial characteristics and the size of the pharyngeal airway space (PAS), taking into account head posture. Sixty dental students 25-30 years of age (30 men and 30 women) were examined by lateral cephalometry. The data were corrected with the use of appropriate regression equations for the PAS. The PAS significantly correlated with hyoid position, maxillary and mandibular size, maxillary and mandibular prognathism, and mandibular inclination. A large, anteriorly positioned mandible was associated with a large PAS-TP (the most proximal distance between the posterior pharyngeal wall and the tongue base). Uvula length and PNS-Ba (the distance between the most posterior point of the hard palate and the most inferior point of the anterior foramen magnum) correlated with PAS-UP (the most proximal distance between the posterior pharyngeal wall and uvula). Our results suggest that the anteroposterior dimension of the PAS is substantially affected by the size of the enclosure surrounding the PAS, including the maxilla, mandible and soft palate.

Adult↗
PubMed2005

Pharyngeal narrowing as a common feature in pycnodysostosis--a cephalometric study.

We report on pycnodysostosis presenting as severe snoring caused by pharyngeal narrowing in two siblings. Cephalograms showed pharyngeal narrowing at the level of the soft palate and the base of the tongue caused by the long soft palate and mandibular hypoplasia. From the literature review and our results, we suggest that respiratory insufficiency such as snoring or obstructed sleep apnea are common and under-appreciated symptoms of pycnodysostosis.

Aged↗
PubMed2005

Incidence and prognostic significance of lateral lymph node metastasis in patients with advanced low rectal cancer.

BACKGROUND: Lateral lymph node metastases occur in some patients with low rectal cancer and may cause local recurrence after total mesorectal excision. The aims of this study were to identify risk factors for lateral node metastases in patients with pathological tumour (pT) stage 3 or pT4 low rectal adenocarcinoma, and to evaluate the prognostic significance of lateral node metastases. METHODS: A retrospective analysis was performed of the outcome of 237 patients with pT3 or pT4 low rectal adenocarcinoma who underwent R0 resection with systematic lateral node dissection. RESULTS: Lateral lymph node metastases were found in 41 patients (17.3 per cent). Increased risk of lateral lymph node metastases was associated with a distal tumour margin close to the anal margin, histological type other than well or moderately differentiated adenocarcinoma, and the presence of mesenteric lymph node metastases. Patients with lateral node metastases had a significantly shorter postoperative survival (5-year survival rate 42 versus 71.6 per cent; P < 0.001) and an increased risk of local recurrence (44 versus 11.7 per cent; P < 0.001) compared with those without lateral node metastases. CONCLUSION: Tumour site, histological type and the presence of mesenteric lymph node metastasis are factors predicting the risk of lateral node metastasis. The poor prognosis of patients with lateral lymph node metastases after systematic lateral dissection suggests the need for adjuvant therapy.

Adenocarcinoma↗
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

Computed tomographic analysis of the position and course of the mandibular canal: relevance to the sagittal split ramus osteotomy.

The aim of this study was to investigate the position and course of the mandibular canal through the mandibular ramus using computed tomographic (CT) imaging and to relate the findings to performing sagittal split ramus osteotomies. The mandibles of 35 patients with skeletal Class III prognathism with symmetry (12 males and 23 females) were observed on transaxial computed tomograms acquired with a slice thickness of 2 mm. The position and course of the mandibular canal from the mandibular foramen to the mandibular body at the level of the second molar were measured at four specific locations in the same plane. Among the 70 rami examined, lack of a bone marrow space on the buccal side, including a fusion type anatomy with no buccal side cortical bone of the mandibular canal, were observed at the CT location between the mandibular foramen and mandibular angle. Our results suggest that special care must be taken when sagittal splitting is performed, and the safest location for the buccal corticotomy is anterior to the mandibular angle.

Adolescent↗
PubMed2004

Achievement of ultralow emittance beam in the accelerator test facility damping ring.

For high luminosity in electron-positron linear colliders, it is essential to generate low vertical emittance beams. We report on the smallest vertical emittance achieved in single-bunch-mode operation of the Accelerator Test Facility, which satisfies the requirement of the x-band linear collider. The emittances were measured with a laser-wire beam-profile monitor installed in the damping ring. The bunch length and the momentum spread of the beam were also recorded under the same conditions. The smallest vertical rms emittance measured at low intensity is 4 pm at a beam energy of 1.3 GeV, which corresponds to the normalized emittance of 1.0x1.0(-8) m. It increases by a factor of 1.5 for a bunch intensity of 10(10) electrons. The measured data agreed to the calculation of intrabeam scattering within much better than a factor of 2.

Journal Article↗
PubMed2004

Genotyping of single nucleotide polymorphism using model-based clustering.

MOTIVATION: Single nucleotide polymorphisms have been investigated as biological markers and the representative high-throughput genotyping method is a combination of the Invader assay and a statistical clustering method. A typical statistical clustering method is the k-means method, but it often fails because of the lack of flexibility. An alternative fast and reliable method is therefore desirable. RESULTS: This paper proposes a model-based clustering method using a normal mixture model and a well-conceived penalized likelihood. The proposed method can judge unclear genotypings to be re-examined and also work well even when the number of clusters is unknown. Some results are illustrated and then satisfactory genotypings are shown. Even when the conventional maximum likelihood method and the typical k-means clustering method failed, the proposed method succeeded.

Algorithms↗
PubMed2003

Earlier surveillance colonoscopy programme improves survival in patients with ulcerative colitis associated colorectal cancer: results of a 23-year surveillance programme in the Japanese population.

Patients with long-standing ulcerative colitis (UC) are known to have an increased risk for the development of colorectal cancer (CRC). The aim of this study was to clarify the cumulative risk for the development of dysplasia or invasive cancer and the effectiveness of surveillance colonoscopy in the Japanese population. A total of 217 patients received a total of 1027 surveillance colonoscopies between January 1979 and December 2001 at the University of Tokyo hospital. Patients with invasive cancer found in the surveillance group were compared to those referred to our hospital from the other hospitals without surveillance colonoscopy. Surveillance colonoscopy confirmed 15 patients with definite dysplasia. Of these, five were proved to have invasive cancer in the resected specimens. The cumulative risk for the development of invasive cancer at 10, 20, and 30 years was 0.5, 4.1, and 6.1%, respectively, while that for the development of definite dysplasia at 10, 20, and 30 years was 3.1, 10.0, and 15.6%, respectively. All the patients with invasive cancer in the surveillance group remained alive, while three out of four patients in the nonsurveillance group died. Our surveillance programme is useful for detecting UC-associated CRC, and survival may be improved by surveillance colonoscopy.

Adolescent↗
PubMed2003

Observation of incoherent diffraction radiation from a single-edge target in the visible-light region.

An experiment to investigate the diffraction radiation from a single edge target has been performed at the accelerator test facility of KEK with the aim of developing noninvasive beam diagnostics. The yield and the angular distribution of diffraction radiation as a function of the impact parameter was measured in the visible light region. The distributions were qualitatively consistent with the theoretical expectation. This work exhibits the first observation of the incoherent diffraction radiation in the visible light region.

Journal Article↗
PubMed2003

Waist-to-height ratio, a simple and practical index for assessing central fat distribution and metabolic risk in Japanese men and women.

OBJECTIVE: The normal body mass index (BMI) range, as defined by the World Health Organization (WHO), is quite wide, and some people within this range may have excessive central fat accumulation and elevated metabolic risks. We hypothesize that the waist-to-height ratio (W/Ht), an effective index for assessing central fat distribution among Japanese people, can be used to identify subjects who are at higher metabolic risk within the normal as well as the overweight range. METHODS: We investigated: (1). the values of BMI, waist circumference, and W/Ht in 6141 men and 2137 women at various age intervals and calculated gender (female to male) ratios for all these anthropometric indices; (2). the relation between age and each anthropometric index, between age and morbidity index for coronary risk factors (sum of the scores for hyperglycemia, hypertension, hypertriglyceridemia, hypercholesterolemia, and low HDL cholesterol; one point for each condition if present), and between morbidity index for coronary risk factors and each anthropometric index; (3). the distributions of the subjects, using various proposed indices of waist circumference (those suggested by WHO, the Japan Society for the Study of Obesity, and the Asia-Pacific perspective), and our proposed boundary value, W/Ht 0.5, among the WHO categories based on BMI; (4). the metabolic risks (coronary risk factors, hyperuricemia, high gamma-glutamyltransferase, and fatty liver diagnosed by ultrasonography), and exercise habits among normal-weight subjects with W/Ht<0.5 or >or=0.5. RESULTS: (1). For the various anthropometric indices in all age groups, the gender ratio for W/Ht was closest to 1, indicating that a single set of values for W/Ht can be used for men and women. (2). Height correlated negatively with age. Among the anthropometric indices, only W/Ht correlated positively with age for both men and women, while age and all anthropometric indices, except height, correlated positively with the morbidity index for coronary risk factors. For both men and women, the highest correlation coefficient was between W/Ht and the morbidity index for coronary risk factors. (3). Nearly all overweight men and women (BMI>or=25) had W/Ht>or=0.5 (98.5% of men and 97.5% of women). None of the underweight subjects had W/Ht>or=0.5. However, 45.5% of men and 28.3% of women of normal weight (BMI 18.5-<25) had W/Ht>or=0.5. W/Ht, of all the indices investigated, was the best index for signaling metabolic risk in the normal-weight subjects as well as the overweight subjects. (4). Age- and BMI-adjusted odds ratios for multiple metabolic risks, and history of no habitual exercise were significantly higher in normal-weight men and women with W/Ht>or=0.5 than in others of normal weight. CONCLUSIONS: Waist circumference is improved by relating it to height to categorized fat distribution of different genders and ages. W/Ht is a simple and practical anthropometric index to identify higher metabolic risks in normal and overweight Japanese men and women.

Abdomen↗
PubMed2003

Prevalence of atopic dermatitis in Japanese adults.

BACKGROUND: Adult atopic dermatitis (AD) in Japan has become a significant social problem, with as many as one-third of adult patients with severe AD absenting themselves from work or classes due to aggravation of the disease. Reports of such patients have become increasingly common in recent years. Despite the pressing need for epidemiological studies to clarify the prevalence and distribution of AD and to determine its aetiology, no previous research has been carried out on the prevalence of AD within the adult population in Japan. OBJECTIVES: To clarify the prevalence of adult AD in Japan, using the U.K. Working Party's diagnostic criteria. METHODS: The subjects of this study were mostly government officials or their family members visiting the Medical Center of Health Science, Toranomon Hospital in Tokyo for annual health check-ups in the period from September 1997 to August 1998. Questionnaires completed by 10 762 persons (8076 men and 2686 women) aged 30 years or above were analysed. The questionnaire consisted of 14 questions on allergic disease. The U.K. Working Party's diagnostic criteria were used after translation into Japanese. Three types of prevalence were used as indicators of prevalence: point, 1-year and lifetime prevalence. RESULTS: The point prevalence, 1-year prevalence and lifetime prevalence of AD in Japanese adults were 2.9%, 3.0% and 3.3%, respectively. No significant statistical differences were observed between the sexes or among age groups within each sex. The survey indicated that 88.6% of those who had ever had AD were currently affected by active AD, while 93.4% of those who had had at least one episode of AD in the past had experienced an episode over the previous year. CONCLUSIONS: This study gives the first indication of the prevalence of adult AD among the Japanese, based on the U.K. criteria. Both the internal and external validity of this study are believed to be high; it would be safe to conclude that the 1-year prevalence of AD in Japanese adult populations living in urban areas is 3.0%.

Adult↗
PubMed2003

Prediction of tumor radiosensitivity in rectal carcinoma based on p53 and Ku70 expression.

The identification of predictive indicators of radiosensitivity is extremely useful in selecting patients suited for preoperative radiotherapy and avoiding unnecessary preoperative treatment. In this study, we evaluated the possible role of the immunohistochemical expression pattern of p53 and Ku70 protein in determining tumor radiosensitivity in rectal cancer before preoperative irradiation. We examined pretreatment biopsy materials from 111 patients by immunohistochemistry. The expression pattern of p53 and Ku70 was evaluated for association with tumor radiosensitivity, which was defined according to the criteria of the Japanese Research Society for Cancer of the Colon and Rectum. There was a significant correlation between the expression pattern of p53 and tumor radiosensitivity (P = 0.045); Ku70 and tumor radiosensitivity (P < 0.001); and the combination of p53 and Ku70, and tumor radiosensitivity (P < 0.001). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in both p53 and Ku70-positive cases for radioresistance were all superior to those of the group positive for p53 alone. In conclusion the examination of the combination of p53 and Ku70 may predict the radiosensitivity of rectal cancer before preoperative irradiation.

Adult↗
PubMed2002

Extremely low vertical-emittance beam in the accelerator test facility at KEK.

Electron beams with the lowest, normalized transverse emittance recorded so far were produced and confirmed in single-bunch-mode operation of the Accelerator Test Facility at KEK. We established a tuning method of the damping ring which achieves a small vertical dispersion and small x-y orbit coupling. The vertical emittance was less than 1% of the horizontal emittance. At the zero-intensity limit, the vertical normalized emittance was less than 2.8 x 10(-8) rad m at beam energy 1.3 GeV. At high intensity, strong effects of intrabeam scattering were observed, which had been expected in view of the extremely high particle density due to the small transverse emittance.

Journal Article↗
PubMed2002

Leukocyte apheresis using a centrifugal cell separator in refractory ulcerative colitis: a multicenter open label trial.

Recently, successful results of ulcerative colitis (UC) treatments with leukocyte apheresis have been reported by several institutes. To certify the efficacy of leukocyte apheresis in refractory UC patients, a multicenter open label trial was conducted, and results were analyzed. Fifty patients diagnosed with active steroid-resistant UC were enrolled in this study from 14 medical centers. Using a centrifugal cell separator (Component Collection System, Haemonetics), leukocyte apheresis was performed once a week for 5 weeks. General conditions and abdominal symptoms were recorded daily, and laboratory tests were followed weekly. Changes of colonoscopic and histological manifestations of luminal activity through the study period were evaluated. At the end of the study period, stool frequency was decreased to less than 4 times a day in 68.4% (26 of 38) and serum C-reactive protein (CRP) concentration was normalized in 56.7% (17 of 30) of the patients. Colonoscopic remission was achieved in 57.7% (26 of 45), and histological improvement was noted in 54.1% (20 of 37) of the patients tested. Improved disease activity was demonstrated in 74% (37 of 50) of the patients by general assessment criteria. Analysis of the trial data confirmed the valid clinical efficacy of leukocyte apheresis by centrifugal cell separator in refractory UC patients.

Adult↗