Biomedical subjects

Tomomi Yamada

Publications and source records attributed to Tomomi Yamada.

17 recordsLinked to original sources

PubMed2006

Risk factors for sensorineural hearing loss in survivors with severe congenital diaphragmatic hernia.

Recent improvements in perinatal management have improved the prognosis in patients with severe congenital diaphragmatic hernia (CDH). However, in surviving patients with severe CDH, hearing loss has sometimes been reported to occur during the follow-up period. Although some of the risk factors for developing sensorineural hearing loss (SNHL) have been reported in CDH, no definitive risk factors have yet been reported. We, therefore, investigated the risk factors regarding postnatal management in patients with severe CDH. In 16 surviving patients with severe CDH, which had all been detected antenatally, and whose lung-to-thoracic ratio was less than 0.2, four patients demonstrated late onset SNHL, which occurred between 1.5 and 5 years of age. The risk factors for SNHL regarding the postnatal treatment for CDH were analyzed between the four patients with SNHL and the remaining 12 patients without SNHL, regarding such factors as the use of ototoxic drugs, neuromuscular blocking agents, high-frequency oscillation (HFO), and inhaled nitric oxide, the duration of hypocapnia, hypoxia, severe acidosis, severe alkalosis, and mechanical ventilation. In addition, the types of neuromuscular blocking agents were also analyzed, including the administration of pancuronium bromide (PB) and vecuronium bromide (VB). The patients with SNHL were found to have a significantly higher risk than the patients without SNHL regarding the duration of loop diuretics usage and the duration of usage of both mechanical ventilation and HFO. Furthermore, all four patients with SNHL used PB. In contrast, none of the five patients using VB developed SNHL The duration and cumulative dose of PB used in the patients with severe CDH showed a significant correlation to the occurrence of SNHL. Although this study was retrospective, based on our data, the prolonged use of PB, in addition to the duration of treatment by loop diuretics, mechanical ventilation, and HFO usage, might, thus, be suggested to be a possible risk factor for late onset SNHL in patients with severe CDH.

Child, Preschool↗

PubMed2006

Long-term functional outcome of brachytherapy for carcinoma of the mobile tongue: focus on the atrophic change of irradiated tongue.

OBJECTIVE: To assess tongue atrophy and long-term functional outcome of mobile tongue cancer patients after interstitial radiotherapy. METHODS: Of 493 patients whose squamous cell carcinoma of the mobile tongue had been treated with low dose rate brachytherapy, there were 57 patients evaluated between July 2002 and April 2004 whose tongue had not been modified by surgical procedures and who had no primary recurrence. The median time from treatment to evaluation was 96 months (range: 9-214 months). Almost all of the patients belonged to the early stage tongue cancer (T1/T2/T3/T4=30:24:3:0), and all had received interstitial radiotherapy with a single-plane implant. To evaluate the deformity of the tongue, we used a grading system that classified the atrophic changes of the tongue into four categories (G0-G3). RESULTS: Thirty-nine patients (70%) showed mild tongue hemiatrophy (G1 or G2) in the irradiated side. However, no patients showed severe atrophy where the tongue cannot be made to protrude beyond the incisors (G3). The length of time after brachytherapy was >72 months and the age of the patients at brachytherapy had the same statistical significance (P=0.0366). As for functional outcome, understandability of speech and a normal diet were preserved for almost all patients. CONCLUSION: The progression of atrophic change in the irradiated tongue occurred over a long term after brachytherapy. However, most patients could maintain their activities of daily life without severe restriction.

Activities of Daily Living↗

PubMed2006

The pharmacokinetics and pharmacodynamics of tandospirone in rats exposed to conditioned fear stress.

The 5-HT1, agonist tandospirone is generally thought to have a weak anxiolytic effect with a slow onset of action. Our recent clinical study suggested that a comparatively high dose of tandospirone has excellent anxiolytic efficacy and is without significant adverse effects. The present study was designed to clarify the relationship between the anxiolytic effect of tandospirone and its plasma and brain concentrations. The anxiolytic effect was estimated by determining the conditioned fear stress-induced freezing behavior in rats after tandospirone administration. Obvious correlations between anxiolytic effect and brain concentration of tandospirone were observed 0.5 and 4 h after tandospirone administration, while the anxiolytic effect was dependent on the plasma concentration of at 0.5 h but not 4 h after tandospirone administration. The plasma concentration was significantly correlated with the brain concentration. These findings suggest that the potency of the anxiolytic effect is dependent on both the plasma and brain concentration.

Animals↗

PubMed2006

A tool for improving the Web accessibility of visually handicapped persons.

Abstract Much has been written concerning the difficulties faced by visually handicapped persons when they access the internet. To solve some of the problems and to make web pages more accessible, we developed a tool we call the "Easy Bar," which works as a toolbar on the web browser. The functions of the Easy Bar are to change the size of web texts and images, to adjust the color, and to clear cached data that is automatically saved by the web browser. These functions are executed with ease by clicking buttons and operating a pull-down list. Since the icons built into Easy Bar are quite large, it is not necessary for the user to deal with delicate operations. The functions of Easy Bar run on any web page without increasing the processing time. For the visually handicapped, Easy Bar would contribute greatly to improved web accessibility to medical information.

Humans↗

PubMed2006

Chromosomal aberrations and microsatellite instability of malignant peripheral nerve sheath tumors: a study of 10 tumors from nine patients.

Malignant peripheral nerve sheath tumor (MPNST) is an uncommon soft tissue neoplasm with a poor prognosis, occurring sporadically or associated with neurofibromatosis type 1 (NF1); however, the histogenesis of MPNST remains unclear, especially in sporadic tumors. There are two major forms of genomic instability in human cancer: chromosomal instability (CIN) and microsatellite instability (MSI). An inverse relationship has recently been demonstrated between CIN and MSI in colorectal cancers. CIN and MSI are suggested to be individual pathways, which are involved in the pathogenesis and which may lead to specific clinical and pathological characteristics. To elucidate the chromosomal aberration as a consequence of CIN and MSI status of MPNST, we karyotyped 10 MPNSTs from nine patients, and examined the MSI of seven microsatellite markers using high-resolution fluorescence microsatellite analysis; 2 out of 10 cases (20%) had normal karyotypes, and 8 out of 10 cases (80%) revealed structural and numerical chromosomal aberrations. Three of the 10 cases (30%) showed near triploidy. The most frequent aberration was -22 (40%), followed by +2, +14, -13, -17, and -18 (30% each). An MSI-low status was observed in 30% of cases; the remaining cases showed microsatellite stability. These findings suggest that chromosomal aberration as a consequence of CIN has a greater role in the pathogenesis of MPNST than does that due to MSI.

Adult↗

PubMed2006

Factors that affect the surgical outcomes of spinal dural arteriovenous fistulas.

BACKGROUND: Authors disclose the factors that affect the surgical outcome of the spinal dural AVFs from the retrospective analysis of 13 cases. METHODS: Thirteen patients with spinal dural AVF underwent microsurgical treatments between 1990 and 2004 at the Department of Neurosurgery, Aso Iizuka Hospital. The mean age was 62 years, and the median time to diagnosis was 38 months (range, 4-120 months). There were 12 men and 1 woman. The clinical features were characterized by spastic paraparesis in all 13 patients and micturition problem in 11 patients. All 13 patients showed the longitudinal extension of the high T2 intramedullary signals in magnetic resonance (MR) image. The microsurgical obliterations of the spinal dural AVFs were performed for all 13 patients because the endovascular treatments were difficult or failed to obliterate the lesions. RESULTS: The durations of the symptoms were not directly correlated to the preoperative neurological conditions and the postoperative outcomes. The patient's age and the preoperative severity of myelopathy affected the postoperative outcomes. The mode of the longitudinal extension of the high T2 intramedullary signals in MR image, rostral or caudal, did not show the statistical significance to the outcome. The poor outcomes were observed in elderly patients and patients with preoperative modified Rankin Scale 4 and 5. A case with multiple spinal dural AVFs is also presented. CONCLUSION: The spinal AVFs are treatable lesions through microsurgery or embolization. The likelihood of favorable outcome was affected by the severity of deficits and the patient's age.

Aged↗

PubMed2006

Aberrant expression of CHFR in malignant peripheral nerve sheath tumors.

Mitotic checkpoint maintains genomic integrity before mitosis. Numerous observations have suggested that mitotic abnormalities produce chromosomal instability and aneuploidy. In MPNST, complex karyotypes showing numerical and structural aberrations have been described. 'Checkpoint with forkhead-associated domain and ring finger' (CHFR) was recently identified as defining a new early mitotic checkpoint. We examined the expression of CHFR in 96 cases of MPNST by immunohistochemical and molecular methods. We found reduced (score, < or = 3) expression of CHFR in 63 out of 96 (66%) cases of MPNST, and such alteration was significantly correlated with a high mitotic count, a high Ki-67-labeling index, and a poor prognosis. In addition, MPNST with normal karyotype showed a strong (score, =5) expression of CHFR. Our results support the assertion that CHFR functions as an inhibitor of tumor proliferation.

Adolescent↗

PubMed2006

Histopathological approach to prostatic contour alterations with the concept of left-right asymmetry.

It has been suggested that prostate cancer spread has predictable patterns, with prostate cancers known to affect the prostatic contours. However, few systematic investigations have documented the associated contour alterations, especially at a clinically localized stage. The purpose of the present paper was to objectively evaluate prostatic contour alterations based on left-right asymmetry, and analyze the histopathological features and prognostic impact. One hundred and sixty-two asymmetrical contours with left-right asymmetry in the length >or=10%, and 278 cancer foci were observed in 114 radical prostatectomy specimens. Of the asymmetrical contours, 55 (34%) were caused by cancer, and of the cancer foci, 55 (20%) generated asymmetrical contours. Cancer-associated asymmetries showed significant correlations with aggressive behaviors such as cancer volume, Gleason score, positive surgical margin, and extraprostatic extension, although these were not significantly associated with unfavorable prognosis. The authors present basic data relating to altered prostatic contours, such as spatial distribution and causative pathological conditions. Clinicopathological characteristics concerning cancer-associated contour alterations, are also presented in detail.

Adenocarcinoma↗

PubMed2006

High-grade and hormone-treated prostate cancer express high levels of thymidylate synthase.

OBJECTIVE: To evaluate the expression of thymidylate synthase and dihydropyrimidine dehydrogenase in prostate tissue. MATERIALS AND METHODS: Tissue from 79 patients with localized prostate cancer was used. Thymidylate synthase and dihydropyrimidine dehydrogenase expression were determined semiquantitatively by immunohistochemistry. RESULTS: Thymidylate synthase and dihydropyrimidine dehydrogenase immunostaining grades of benign tissue were significantly higher than those of cancer tissue (both P < 0.01). Cancer tissue with a primary Gleason grade of > or = 4 expressed a higher thymidylate synthase staining grade than those with a primary Gleason grade of <4 (P < 0.01). Cancer tissue spots from patients treated with neoadjuvant therapy revealed significantly higher thymidylate synthase and dihydropyrimidine dehydrogenase grades than those with no neoadjuvant therapy (P < 0.01). CONCLUSION: High thymidylate synthase expression in localized prostate cancer might reflect an aggressive status. High expression in high-grade prostate cancers and prostate cancers after hormonal therapy suggest that thymidylate synthase could be a new therapeutic target for advanced prostate cancer.

Aged↗

PubMed2006

Geriatric patients presenting to the emergency department of a Japanese university hospital.

To evaluate the trend of elderly patients visiting the emergency department of a Japanese University Hospital, out patient-based records were reviewed of the emergency department of Kyushu University Hospital from 2000 to 2004. A total number of 7610 emergency patients visited the department during the five year period. The median (25%, 75%) of age was 32 (22, 56). Patients aged 65 years and over accounted for 16% of all attendances. All the patients were classified into 6 groups according to the diagnosis, (1) Respiratory, (2) Circulatory, (3) Central nervous system, (4) Abdominal, (5) Trauma, and (6) Others. The median age in each group was (1) 27 (15, 49), (2) 66 (53, 76), (3) 51 (27, 67), (4) 33 (22, 56), and (5) 26 (20, 46), respectively. There was a statistically significant difference observed, reciprocally except between (1) and (5) (P < 0.05). The patients showed statistically significant difference in the annual transition of the disease (P < 0.0001). In the elderly, the annual transition of the disease showed statistically significant decreases in Circulatory (P = 0.0015) and in Central nervous (P < 0.0001), and an increase in Abdominal (P < 0.0001), respectively. Death rate at the outpatient clinic in the elderly showed much higher than in the younger (P < 0.0001). Admission rate was also much higher in the elderly than in the younger (P < 0.0001). Elderly emergency patients have both internal and external intrinsic factors. They have to be treated carefully since their condition easily deteriorates. Provisions for the problems surrounding the elderly should be made as a nationwide effort.

Age Factors↗

PubMed2005

Clinical significance of serum levels of vascular endothelial growth factor and its receptor in biliary disease and carcinoma.

AIM: To investigate the clinical significance of serum vascular endothelial growth factor (VEGF) and soluble VEGF receptor-1 (VEGFR1/Flt-1) (sVEGFR1) levels in biliary diseases. METHODS: We analyzed the serum levels of these proteins in patients with acute cholangitis (group 1), biliary malignancies (group 2), and primary biliary cirrhosis or primary sclerosing cholangitis (group 3), and in healthy donors (group 4). The influence of inflammation was also analyzed. Serum VEGF levels were expressed as VEGF per platelet (VEGF/PLT, pg/10(6)) in order to exclude the influence of platelet counts. RESULTS: sVEGFR1 levels were significantly higher in groups 1 and 2 than in the control group, but did not correlate with inflammatory markers. VEGF/PLT levels were generally higher in patients with active inflammation than in those with carcinoma. C-reactive protein strongly correlated with the levels of serum VEGF independently of platelet and leukocyte counts, even in cancer patients. In cancer patients, VEGF/PLT and sVEGFR1 levels might be indicators for evaluating the effect of medical treatment or the disease progression. CONCLUSION: Serum VEGF and VEGFR1 might be useful markers for gauging the clinical effect of various treatments on patients.

Bile Duct Diseases↗

PubMed2005

Prognostic value of thymidine phosphorylase activity in liver tissue adjacent to hepatocellular carcinoma.

BACKGROUND: Measurement of thymidine phosphorylase (TP) activity in normal liver tissue adjacent to hepatocellular carcinoma (HCC) may predict multicentric recurrence a long time after an operation. The authors investigated this activity in 92 patients with HCC who had a single HCC equal to or less than 5 cm. METHODS: Fresh samples (tumors with adjacent normal tissues) were collected from 92 patients with HCC who underwent curative hepatic resection. The levels of TP activity in nonfixed, fresh, and frozen HCC specimens with adjacent noncancerous liver tissue were biochemically measured by using an enzyme-linked immunosorbent assay method. RESULTS: Patients who had a high TP level in normal liver tissue had significantly earlier recurrence (median disease-free survival, 819 days; 95% confidence interval [95% CI], 478-1044 days) compared with patients who had a low TP level (median disease-free survival, 1376 days; lower limit of 95% CI, 921 days; P = 0.0171). Multivariate analysis showed that patients who had a low TP level in adjacent liver tissue had a 0.387-fold higher risk of postoperative recurrence compared with patients who had a high TP level (P = 0.0067). CONCLUSION: TP activity in normal liver tissue adjacent to HCC is related to tumor occurrence and may predict postoperative tumor recurrence.

Aged↗

PubMed2005

Prognostic significance of expressions of cell-cycle regulatory proteins in gastrointestinal stromal tumor and the relevance of the risk grade.

Gastrointestinal stromal tumors (GISTs) have a wide spectrum of biologic behavior ranging from benign to malignant. Risk grading based on tumor size and mitotic counts has been proposed in an effort to predict the adverse outcome of GIST in the literature so far. Recent molecular studies have reported the prognostic values of several parameters, including alteration of cell-cycle regulators. The aim of this study was to elucidate the prognostic values of risk grade and alterations of cell-cycle-related proteins, including Ki-67, cyclin A, cyclin B1, cyclin D1, cyclin E, p16, p21, p27, p53, cdc2, and cdk2, in addition to the conventional factors. Eighty cases of primary c-kit-positive GISTs were classified into 2 cases of very-low-risk grade, 20 cases of low-risk grade, 25 cases of intermediate-risk grade, and 33 cases of high-risk grade. The risk grade was correlated with the presence of metastases and/or recurrence. A high level of Ki-67 and cyclin A expression was correlated with risk grade (P = .0027 and .0441, respectively). Overexpression of G2-M regulators, such as cyclin A, cyclin B1, and cdc2, was associated with the Ki-67 labeling index (LI) (P = .0007, .0475, and .0040, respectively). According to univariate analysis, tumor grade (high risk), tumor size (> or =5 cm), mitotic counts (> or =5/50 high-power fields), Ki-67 LI (> or =4.92%), cyclin A LI (> or =1.61%), and cdc2 LI (> or =1.25%) were all found to be significantly associated with a shorter period of disease-free survival (P = .0001, .0270, .0004, .0001, .0001, and .0011, respectively). According to multivariate analysis, both high Ki-67 LI and high-risk grade were found to be significantly associated with a shorter period of disease-free survival (P = .0083 and .0246, respectively). In conclusion, our results strongly support the hypothesis that Ki-67 LI and risk grade are useful for predicting the aggressive biologic behavior of GISTs. Furthermore, alteration of G2-M regulators, such as cyclin A, cyclin B1, and cdc2, is also a useful marker for predicting aggressive behavior and play an important role, at least in part, in the cell proliferation of GIST.

Aged↗

PubMed2005

Androgen receptor, Ki67, and p53 expression in radical prostatectomy specimens predict treatment failure in Japanese population.

OBJECTIVES: To evaluate multiple known prognostic markers in localized prostate cancer using tissue microarrays in Japanese patients. Molecular studies have suggested that ethnicity influences prostate tumor biology. METHODS: Specimens were studied from 52 patients who underwent radical surgery at our institution between 1997 and 2001 without neoadjuvant hormonal therapy and with three or more available and complete cancer spots. Ki67, p53, and androgen receptor antigen expression were examined. Immunohistochemical scores were compared with outcomes of chemical relapse as monitored using prostate-specific antigen. RESULTS: Pathologic tumor classification (P = 0.047), World Health Organization score (P = 0.026), World Health Organization histologic grade (P = 0.026), and surgical margin status (P = 0.018) were significant conventional clinicopathologic variables for predicting biochemical failure. The tissue microarray Gleason sum (P = 0.038), tissue microarray primary Gleason grade (P = 0.013), Ki67 labeling index (P < 0.0001), p53 (P = 0.0097), and androgen receptor (P = 0.0113) antigen expression also were significant. Moreover, surgical margin status and Ki67 labeling index were independently associated with treatment failure. CONCLUSIONS: Especially together, the Ki67 labeling index and p53 and androgen receptor expression in localized prostate cancer often predicted postoperative progression in Japanese patients.

Aged↗

PubMed2005

Aluminum chloride does not facilitate deposition of human synthetic amyloid beta1-42 peptide in the rat ventricular system of a short-term infusion model.

Recent data have demonstrated that a 39-43 amino acid peptide called beta-amyloid peptide (Abeta), which predominantly contains 42 residues (Abeta1-42), has a strong tendency to form insoluble aggregates and that the toxic effects of Abeta are based on its aggregation. In a previous study, we reported that infusion of 100 microg of human synthetic Abeta1-42 (sAbeta1-42), which is a main component of diffuse plaques, into the lateral ventricle of the rat brain of a short-term infusion model resulted in almost complete disappearance of sAbeta1-42 aggregates from the ventricles by 28 days. In addition, aluminum is considered a potential etiological factor in Alzheimer's disease (AD). Neurotoxicity from excess brain exposure to aluminum has been documented from both clinical observations and animal experiments, although a direct relationship between aluminum and AD has yet to be clearly established. We therefore investigated the effects of sAbeta1-42 aggregates with aluminum chloride (AlCl3) in the ventricular system of the rat brain of a short-term infusion model. At either 2 or 7 days following infusion, sAbeta1-42 formed aggregates with AlCl3 that spread throughout the entire ventricular system. However, sAbeta1-42 aggregates with AlCl3 had almost disappeared from the ventricles by 28 days, resulting in similarities with respect to the time-course and the neuropathological changes observed in sAbeta1-42 aggregation without AlCl3. We herein report for the first time that considerable amounts of sAbeta1-42 aggregates with AlCl3 almost disappear from the rat ventricular system by 28 days post-infusion.

Aluminum Chloride↗

PubMed2005

Higher small arterial elasticity in hypertensive patients treated with angiotensin II receptor blockers.

Although evidence from basic research suggests the involvement of angiotensin II (Ang II) in the progression of arteriosclerosis, the clinical data are limited. In the present study, hypertensive outpatients who were well controlled with antihypertensive medication and had similar blood pressure levels were studied, and arterial elasticity was compared between those receiving Ang II receptor blockers (ARBs) and those treated with other antihypertensive agents. The effects of HMG-CoA reductase inhibitors (STs) on arterial elasticity were also evaluated. The study enrolled 298 outpatients who had been diagnosed with essential hypertension whose blood pressure was controlled to 150/95 or less by antihypertensive treatment (excluding angiotensin converting enzyme [ACE] inhibitors) for at least 2 months. The small artery elasticity index (SAEI) was determined for each patient from the radial artery pulse waves using a non-invasive pulse wave analysis system CR-2000. The mean of two blood pressure measurements taken from subjects lying in a recumbent position during SAEI analysis was used for the data analysis. The patients were grouped according to the use of ARBs and STs, and two-way analysis of variance (ANOVA) was used for statistical comparisons. A backward stepwise multiple regression analysis was carried out to identify factors contributing to the SAEI. Hypertensive patients receiving ARB treatment had a significantly higher SAEI compared to those not receiving ARBs, despite the similar blood pressure levels of both groups. No significant effects of ST treatment on the SAEI were observed (two-way ANOVA). A backward stepwise multiple regression analysis for the SAEI suggested that ARB treatment was an independent determinant of the SAEI after the adjusting of age, gender, total cholesterol, high density lipoprotein cholesterol, smoking and systolic blood pressure. Our results suggested that while providing blood pressure control similar to that of other antihypertensive agents, ARBs may also increase vascular elasticity and thereby delay the progression of arteriosclerosis.

Aged↗

PubMedDate not supplied

Brilliant blue G selectively stains the internal limiting membrane/brilliant blue G-assisted membrane peeling.

PURPOSE: To report the use of the dye brilliant blue G (BBG) for staining of the internal limiting membrane (ILM) during macular hole (MH) and epiretinal membrane (ERM) surgery. METHODS: This study was designed as an interventional, noncomparative, prospective, clinical case series. Twenty eyes from 20 consecutive patients with MH or ERM underwent BBG-assisted ILM and ERM removal. In MH cases, a posterior vitreous detachment was created, followed by the injection of 0.25 mg/mL BBG solution into the vitreous cavity and immediate washout of the BBG. This technique improved visualization of the ILM, enabling peeling and surgery to be performed successfully. However, in ERM cases, staining of the ERM could not be confirmed at this concentration. Finally, the ILM including the ERM was removed in all cases. Preoperative and postoperative ophthalmic examinations were performed. RESULTS: Postoperatively, 17 patients (85%) had visual acuity improved by at least 2 Snellen lines. No adverse effects were observed postoperatively during the observation period (mean follow-up +/- SD, 7.3 +/- 1.0 months). CONCLUSIONS: BBG selectively stains the ILM. This technique can facilitate the management of MH and ERM surgery without any adverse effects, as was shown in this short-term study.

Adult↗