Biomedical subjects

T Tsuda

Publications and source records attributed to T Tsuda.

At least 199 records · Page 11Linked to original sources

PubMed1997

Bilateral adrenal neuroblastoma.

Neuroblastoma has been recognized as the most common solid tumor of infancy and childhood. The occurrence of bilateral adrenal neuroblastoma, however, is extremely rare and only a small number of cases have been previously reported. The authors herein report the clinical, histopathological and molecular biological features of two bilateral adrenal cases out of 125 neuroblastoma patients treated at Kyushu University Hospital over a 35-year period. The clinical and histopathological data of the two cases of bilateral adrenal neuroblastoma were reviewed. In Case 1, which had multiple liver metastases, a post-mortem examination revealed bilateral adrenal involvement. In Case 2, which had been detected by mass screening, CT showed masses in both adrenal glands. No big differences in size were recognized between the tumors in either of the cases. A histopathological examination revealed rosette fibrillary type neuroblastomas in both cases. The DNA of these tumor samples stored at -80 degrees C was extracted and the number of copies of the N-myc gene was determined by a Southern blot analysis. Fourteen copies of the gene were detected in Case 1, whereas neither of the tumors in Case 2 showed any amplification. The clinical outcome, histopathological findings and N-myc gene analysis of two cases might support the variety of biological features of this rare group of neuroblastoma.

Adrenal Gland Neoplasms↗

PubMed1997

Spectral analysis applied to hepatobiliary dynamic scintigraphy with 99Tcm-N-pyridoxyl-5-methyltryptophan.

This study was performed to evaluate the application of spectral analysis (SA) to hepatobiliary dynamic scintigraphy with 99Tcm-N-pyridoxyl-5-methyltryptophan (99Tcm-PMT) in 82 patients with a wide range of liver function, and to compare it with compartment analysis (CA) and deconvolution analysis (DA). The rate of uptake of PMT by the liver from the blood (k1) obtained by SA (y, min-1) agreed well with the k1 value obtained using CA (x, min-1) (y = 1.079x + 0.000, r = 0.993, standard error of the estimate (S.E.E.) = 0.042 min-1). The mean residence time (MRT) of PMT in the liver obtained by SA (y, min) also agreed well with the MRT value obtained by DA (x, min) (y = 1.036x - 0.759, r = 0.967, S.E.E.-1.014 min) and that obtained by CA (x, min) (y = 0.859x + 1.006, r = 0.931, S.E.E. = 1.428 min). The fraction of the measured blood activity superimposed on the true liver activity (f) obtained by SA (y) correlated well with the f value obtained by CA (x) (y = 1.168x - 0.004, r = 0.924, S.E.E. = 0.043). We conclude that the application of SA to hepatobiliary dynamic scintigraphy with PMT appears to be useful in evaluating the functional status of the liver, since it facilitates the interpretation of the kinetic behaviour of PMT in the liver and allows us to extract quantitative parameters corresponding to those obtained by CA or DA.

Biliary Tract↗

PubMed1997

A case of malignant pleural mesothelioma following exposure to atomic radiation in Nagasaki.

We report the case of a 75-year-old Japanese man who developed malignant mesothelioma in the left hemithorax 50 years after the dropping of the atomic bomb on Nagasaki in 1945. This may be the first reported case of malignant mesothelioma following exposure to atomic radiation. Asbestos is the leading cause of malignant mesothelioma, but radiation therapy is the primary non-asbestos-related cause. In the case of radiation therapy, the interval between exposure and the occurrence of malignant mesothelioma tends to be many years. This patient was at a high risk of malignant mesothelioma as he had been exposed to radiation from the atomic bomb and may also have had a history of asbestos exposure at the munitions factory where he was employed as a shipbuilder for 2 years. It has been suggested that combined exposure to atomic radiation and asbestos is associated with an increased incidence of malignant mesothelioma. If thickening of the pleura or pleural effusion is found in atomic bomb survivors, malignant mesothelioma should be considered as one of the options in the differential diagnosis, even although the atomic bomb attacks occurred several decades ago.

Aged↗

PubMed1997

Elevated soluble intercellular adhesion molecules-1 in inflammatory myopathy.

INTRODUCTION: We evaluated the serum level of soluble intercellular adhesion molecule-1 (sICAM-1) in patients with polymyositis (PM) and dermatomyositis (DM) and investigated the correlation between the serum level of sICAM-1 and clinical findings. MATERIAL AND METHODS: We measured the serum level of sICAM-1 using an enzyme-linked immunosorbent assay in 19 untreated patients with inflammatory myopathy (14 patients with PM and 5 patients with DM), 20 patients with other neuromuscular disorders in which immunological mechanisms are unlikely to be involved, and 14 normal healthy controls. RESULTS: The serum level of sICAM-1 was significantly higher in patients with PM/DM compared with patients with other neurological disorders and control subjects. The sICAM-1 level was, however, not correlated with the clinical characteristic including disease severity, the duration of illness, and the serum level of CK. CONCLUSION: These findings suggest that sICAM-1 is involved in the inflammatory process of PM and DM.

Adult↗

PubMed1997

Effect of gastrin-releasing peptide receptor number on receptor affinity, coupling, degradation, and modulation.

The relationship between receptor number and agonist-induced intracellular responses has been well studied in receptors coupled to adenylate cyclase; however, for receptors coupled to phospholipase C (PLC), very little is known about the effect of receptor number on receptor-mediated processes. To explore this issue, we investigated the effect of the number of receptors for gastrin-releasing peptide (GRP) on ligand affinity and on the ability to activate intracellular messengers [PLC, tyrosine phosphorylation of p125 focal adhesion kinase (p125FAK)] and cause receptor modulation (internalization, desensitization, down-regulation) and ligand degradation. Three BALB 3T3 cell lines were made that stably expressed the gastrin-releasing peptide receptor (GRP-R) with receptor numbers varying by 280-fold (GRP-R-Low, GRP-R-Med, and GRP-R-Hi). Each cell line had the same affinity for agonist. The efficacy for bombesin to increase [3H]inositol phosphates but not tyrosine phosphorylation of p125FAK correlated well with receptor number. In contrast, the EC50 value for [3H]inositol phosphate generation for bombesin was the same in each cell line. Receptor number did not alter internalization. In the absence of protease inhibitors, there was an inverse correlation between receptor number and receptor down-regulation and desensitization. However, with protease inhibitors present, GRP-R-Med and GRP-R-Hi down-regulated significantly less than the GRP-R-Low. Similarly, GRP-R-Low desensitized significantly more than GRP-R-Med or GRP-R-Hi. GRP-R-Hi caused significantly greater ligand degradation than GRP-R-Low, and protease inhibitors completely inhibited degradation by GRP-R-Low and inhibited degradation by 70% for GRP-R-Hi. In conclusion, we show that for the PLC-coupled GRP-R, receptor number had little or no effect on binding affinity, potency for activating PLC, tyrosine phosphorylation of p125FAK, or extent of receptor internalization. In contrast, receptor number had an effect on ligand degradation, down-regulation, desensitization, and efficacy of PLC activation without altering the efficacy of tyrosine phosphorylation of p125FAK. These results demonstrate that the effect of receptor number differs for the different functions mediated by the GRP receptor and differs from that reported for adenylate cyclase-coupled receptors such as receptors mediating the action of adrenergic agents, secretin, and opioids.

3T3 Cells↗

PubMed1997

Calpain and cathepsins in the skeletal muscle of inflammatory myopathies.

To clarify the significance of intracellular lysosomal (cathepsins B, L and H) and extralysosomal (calpain) proteolytic systems in the process of muscle fiber degradation in inflammatory myopathies, biopsied muscle specimens were examined from patients with polymyositis (PM) and dermatomyositis (DM). Generally, in specimens from patients with PM and DM, but not in those from normal controls, muscle fibers surrounding inflammatory infiltrates or in the perifascicular regions, and occasionally mononuclear cell infiltrates demonstrated positive immunostaining for calpain and cathepsins B, L, and H. In addition, enzyme activities of cathepsins B and L increased in specimens with inflammatory myopathy. These results suggest that calpain and cathepsins play a significant role in the process of muscle fiber destruction in inflammatory myopathy.

Adult↗

PubMed1997

Organization of the lamina propria mucosae of rat intestinal mucosa, with special reference to the subepithelial connective tissue.

Light microscopy, scanning electron microscopy and transmission electron microscopy have been used to delineate the structure and function of the lamina propria mucosae in the rat jejunum. In silver-impregnated sections, the adepithelial surface of the lamina propria mucosae was framed by a sheet of reticular fibers (reticular sheet). Short-term (3-hour) immersion of jejunal tissues in 2 N NaOH solution enabled us to simultaneously view networks of reticular fibrils and fibroblasts residing in the subepithelial connective tissue under a scanning electron microscope. The reticular fibrils, which measured about 40 nm in diameter and were interwoven in dense networks, formed a sheet 2-3 microns thick. In the villi, this sheet contained numerous foramina ranging from 3 to 7 microns in diameter, through which lymphocytes, macrophages, basal extensions of epithelial cells and fat particles traversed. The reticular sheet in the domes of isolated lymphoid nodules was markedly porous, and many lymphocytes migrated into or out of the epithelium through the foramina. The formaina of the reticular sheet may participate in the communication between the intestinal epithelium and the lamina propria mucosae. It was noted that the foramina of the reticular sheet in the villi were surrounded by end feet of the cytoplasmic processes of fibroblasts. In addition, these fibroblasts were combined with lymphocytes or dendritic cells in the lamina propria mucosae.

Animals↗

PubMed1997

Interfamilial and intrafamilial phenotypic heterogeneity in familial Alzheimer's disease.

The features of Alzheimer's disease (AD) are very heterogenous, and some component of the variability of AD is likely to be related to genetic factors. To investigate this question, we evaluated 19 clinical neuropsychiatric and brain imaging features in 32 familial Alzheimer's disease (FAD) kindred, primarily of late onset. Within families, patients displayed a high degree of phenotypic heterogeneity (PH), which occurred irrespective of gender, ethnicity, or apolipoprotein E genotype. Overall, an equivalent amount of PH was observed in both the between- (37%) and within-family (31%) groups. However, for onset age and rate of decline between families, there was greater PH than within families (P = .002 and P = .01, respectively). A similar trend was found for severity of cortical atrophy (P = .05). These observations suggest a weak genetic influence, and possibly strong nongenetic influences, on the degree of phenotypic heterogeneity in late-onset FAD. In early-onset AD kindred, a much smaller degree of phenotypic heterogeneity may be expected within families, because genetic influences in phenotypic expression tend to be more prominent in early-onset cases.

Aged↗

PubMed1997

Relationship between Asbestos Exposures and 8-Hydroxydeoxyguanosine Levels in Leukocytic DNA of Workers at a Chinese Asbestos-material Plant.

The objective of the study was to evaluate the level of 8-hydroxydeoxyguanosine (8-OHdG) in DNA of peripheral-blood leukocytes as a biological marker of asbestos exposure and/or its fibrotic effects in an occupational population exposed to asbestos. The setting was a large-scale asbestos plant in China producing brake linings, asbestos rubber, and textile using chrysotile. From a base population of active and retired workers with various levels of cumulative exposure to asbestos and grades of asbestosis, 39 study subjects were randomly selected to reflect incremental grades of asbestosis based on Chinese diagnostic standards. They consisted of 19 "normal" (control) and ten "suspected" and ten "definite" asbestosis-grade subjects, group-matched for age and sex. Leukocytic DNA was extracted from 5-mL samples of peripheral blood and 8-OHdG level measured by high-pressure liquid chromatography. A cumulative asbestos exposure index (CEI) was calculated for each subject as the summed product of duration and level of asbestos exposure per job, incorporating a job-exposure matrix. Geometric mean 8-OHdG levels showed a positive gradient in relation to increasing grades of asbestosis (control: 1.78, suspected: 2.21, definite: 2.58), with a significant difference between the control and definite-asbestosis subgroups (p < 0.05). The 8-OHdG level of the two subgroups combined as one "asbestosis" group was significantly higher than that of the control group (control: 1.78, asbestosis: 2.39, p = 0.01). Further, 8-OHdG levels were moderately correlated with CEIs for all subjects (r = 0.35, p < 0.05) and with grades of asbestosis for all (r = 0.47, p < 0.01) and for male subjects (r = 0.43, p < 0.05). In multiple regression analyses, grade of asbestosis explained 27% of the total variation in 8-OHdG and was a better predictor than CEI or duration of exposure. Thus, the 8-OHdG level in leukocytic DNA is related to grade of asbestosis and to individual cumulative exposure and may serve as a biologic marker reflecting the status of oxidative DNA damage by asbestos.

Journal Article↗

PubMed1997

A presenilin-1 mutation in a Japanese family with Alzheimer's disease and distinctive abnormalities on cranial MRI.

Some patients with familial Alzheimer's disease (FAD) have mutations in the presenilin-1 (PS-1) gene on chromosome 14. We report a Japanese family with AD and an Ala285Val substitution in exon 8 of the PS-1 gene. FAD in this family was characterized by relatively late onset (mean age, 50 years) and absence of myoclonus, seizures, or paratonia. Levels of tau were markedly elevated in CSF whereas CSF levels of amyloid beta protein were normal. MRI of the cranium showed marked linear signal abnormalities within white matter in the parieto-occipital lobes, consistent with cortical amyloid angiopathy of the type encountered in patients with the PS-1 gene mutation.

Alzheimer Disease↗

PubMed1997

[Causal inference in medicine: a reaction to the report, "incidence of Minamata disease in communities along the Agano River, Niigata, Japan--patterns of the exposure and official diagnosis of patients"].

Kondo's "Incidence of Minamata Disease in Communities along the Agano River, Niigata, Japan (Jap. J. Hyg. 51:599-611;1996)" is critically reviewed. The data of the article were obtained from most of the residents living in the Agano river villages where Minamata disease was discovered in June, 1965. However, sampling proportions were much different between in the population base and in the cases. The method of identification of cases from the data and the reason for the difference were not clearly demonstrated. The citations of reference articles are insufficient despite the fact that other epidemiologic studies on methyl-mercury poisoning have been reported not only in Japan, but also around the world. His "analysis of the recognized patients" is erroneous. Both the sampling scheme of information of hair mercury and the modeling of the analysis are based on Kondo's arbitrary interpretation, not on epidemiologic theory. His "analysis of the rejected applicants" is also erroneous. His calculations of the attributable proportion are incorrect and self-induced in both the assignments of data and analysis of data. Kondo has failed to study the epidemiologic theories in light of changes in the field. Therefore, his article is lacking in epidemiologic theory, a logical base and scientific inference. In Japan, epidemiologic methodology has rarely been used in studies on Minamata Disease in either Kumamoto and Niigata. The government has used neurologically specific diagnosis based on combinations of symptoms to judge the causality between each of symptoms and methyl-mercury poisoning. Epidemiologic data obtained in Minamata, Kumamoto in 1971 indicate that the criteria set by the government in 1977 have produced much more false-negative patients than false-positive patients. As a result, a huge number of symptomatic patients, including those with peripheral neuropathy or with constriction of the visual field, did not receive any help or compensation until 1995. The authors emphasize that the causal relationship between each symptom and methyl-mercury exposure should be reevaluated epidemiologically in Japan.

Epidemiologic Methods↗

PubMed1997

Effects of mineral fibers on the expression of genes whose product may play a role in fiber pathogenesis.

To determine which factors are useful for the risk assessment of man-made fibers, we examined the gene expression of proinflammatory cytokines, growth factors, manganese superoxide dismutase (MnSOD), and inducible nitric oxide synthase (iNOS) in mineral fiber-exposed rats by means of reverse transcription-polymerase chain reaction (RT-PCR). Male Wistar rats received a single intratracheal instillation of either saline (control) or two types of fibers (2 mg of Union Internationale Centre le Cancer (UICC) chrysotile or alumina silicate refractory ceramic fiber [RCF]). Expression of interleukin-1 alpha (IL-1 alpha), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha), platelet-deriving growth factor-A, (PDGF-A), platelet-deriving growth factor-B (PDGF-B), transforming growth factor beta 1 (TGF-beta 1), basic fibroblast growth factor (bFGF), MnSOD, and iNOS mRNA from lung and lipopolysaccharide (LPS)-stimulated alveolar macrophages (AM) were assessed by RT-PCR. Among these factors, IL-1 alpha, TNF-alpha, IL-6, bFGF, and iNOS would be the possible parameters for the risk assessment of fibers. In a follow-up study, we investigated the time course (3 days, 1 week, 1 month, and 3 months) of expression of IL-1 alpha and TNF-alpha by LPS-stimulated AM exposed to mineral fibers in vivo. Male Wistar rats were instilled intratracheally with saline or fibers (2 mg of Union Internationale Contre le Cancer UICC crocidolite or potassium octatitanate whisker [TW]). The expression of IL-1 alpha mRNA by fibers was greatest in TW, crocidolite, chrysotile, and RCF-instilled rat AM, in that order. The increase of IL-1 alpha and TNF-alpha mRNA in AM peaked at 1 month and 3 days after exposure to crocidolite or TW, respectively. The expression of IL-1 alpha by fibers (crocidolite, chrysotile, TW, and RCF) may be a good indicator of the pathologic potential of fibers.

Administration, Inhalation↗

PubMed1997

Expression of matrix metalloproteinases, tissue inhibitors of metalloproteinases, and extracellular matrix mRNA following exposure to mineral fibers and cigarette smoke in vivo.

To determine the effect of mineral fibers and cigarette smoke on remodeling of lung tissues, we examined matrix metalloproteinase-1 (MMP-1), MMP-2, tissue inhibitors of metalloproteinase-1 (TIMP-1), TIMP-2, and types I and IV collagen mRNA levels from rat lungs exposed to mineral fibers and/or cigarette smoke in vivo. Male Wistar rats (10 weeks of age) were given a single intratracheal instillation of 2 mg of chrysotile or alumina silicate ceramic fibers (RCF). Animals were then exposed to cigarette smoke (side stream) 5 days per week for 4 weeks. Transcriptional levels of mRNA extracted from the lungs were assessed by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). Exposure to cigarette smoke induced increases in MMP-1 and TIMP-1 mRNA levels and decreased TIMP-2 and type I collagen mRNA levels in lung. Chrysotile or RCF stimulated the expression of MMP-1 mRNA in the lung. The mineral fibers and cigarette smoke had more than additive effects on the expression of MMP-2 and TIMP-1 in the lung. These data suggest that the imbalance of the expression of MMPs, TIMPs, and extracellular matrix may be associated with the remodeling of lung tissues induced by mineral fibers and/or cigarette smoke.

Administration, Inhalation↗

PubMed1997

Multiple hemorrhagic gastric ulcers due to polyarteritis nodosa.

A 73-year-old man developed refractory multiple hemorrhagic gastric ulcers. Emergent gastrectomy was performed, and the diagnosis of polyarteritis nodosa was made by histologic evaluation of the resected stomach. Although gastric ulceration is a relatively rare complication of polyarteritis nodosa, it should be considered in the differential diagnosis of refractory hemorrhagic gastric ulcers. Emergent surgery may be indicated in such cases.

Aged↗

PubMed1997

Severity of neurological disorders in elderly residents of a farming town in Kyushu, Japan; prevalence of disability in activities of daily living.

Activities of daily living (ADL) were evaluated in 421 elderly people, aged 60-95, who resided in 27 randomly selected communities in the town of Mifune, Japan. The disability of ADL increased with age, and was particularly rapid after age 80. Most of the elderly were independent; the prevalence of dependent elderly ranged from 0.7% (in feeding) to 9.5% (in working). The prevalence of dependent elderly increased markedly after age 80 in all ADL items, especially those related to behavior such as ambulation, stair climbing, transfers, and working (i.e., employment, housekeeping, etc.). These results emphasize the importance of community health care of the elderly for preventing and treating neurological disorders which comprised the main cause of disabilities of behavioral ADL.

Activities of Daily Living↗

PubMed1997

The relationship between job stress and mental health at work.

In order to evaluate the relationship between job stress and mental health, a cross-sectional study was conducted using a questionnaire relating to demographics, subjective job stress and mental health state. The questionnaire consisted of a 30-item Japanese version of the General Health Questionnaire (GHQ) developed by Goldberg in addition to questions about subjective job stress, to measure mental health and job stress conditions, respectively. All subjects were employees of an electronic company in Japan. Among 782 workers, 763 workers responded to the questionnaire satisfactorily (response rate was 97.6%). People whose GHQ score was more than 7 were classified as having psychiatric problems, while the remaining respondents were considered as having no mental health problems. We employed a multiple logistic regression analysis to estimate the relationship between subjective job stress and mental health, adjusting for gender, age, marital state, familial stress, and physical health state. Subjective job stress was significantly associated with the state of mental health. In particular, the items of "too much trouble at work," "too much responsibility," "are not allowed to make mistakes," "poor relationship with superiors," and "cannot keep up with technology" were significantly related to mental health.

Adult↗

PubMed1997

Intratumoral necrosis of lung carcinoma: a potential diagnostic pitfall in incremental dynamic computed tomography analysis of solitary pulmonary nodules?

The authors determined the pattern and enhancement range of necrotic lung carcinoma using incremental dynamic computed tomography (CT). Thirty-seven pathologically proven lung cancers (range, 8-57 mm in diameter) were evaluated using incremental dynamic CT. Scans were obtained before and 30 seconds, 2 minutes, and 5 minutes after the onset of contrast material injection. Computed tomography numbers in circular regions of interest (60% of tumor diameter) were calculated, and the difference in CT number between nonenhanced and the scan showing maximum attenuation was determined. In cavitary necrotic carcinomas, regions of interest were established excluding areas of cavitation. Nine (24%) of 37 lung carcinomas had intratumoral necrosis; four (11%) had noncavitary necrosis, and five (14%) had cavitary necrosis. Maximum attenuation of four noncavitary necrotic carcinomas (mean 31 +/- standard deviation 25 HU; range, -3-56 HU) was lower than cavitary necrotic carcinomas (42 +/- 8 HU; range, 35-51 HU; p = 0.36) and non-necrotic carcinomas (48 +/- 17 HU; range, 25-91 HU; p = 0.07). All carcinomas showed maximum attenuation > or = 25 HU except for one noncavitary necrotic carcinoma (maximum attenuation = -3 HU; 36 mm in diameter). Noncavitary necrosis was recognized as low attenuation on noncontrast scan in two of four cases and as an unenhanced area on enhanced scan in four of four cases. Although noncavitary necrotic lung carcinoma may rarely show maximum attenuation < or = 15 HU, necrotic material is recognized as unenhanced area on enhanced scan.

Aged↗

PubMed1997

[Public health center based educational approach for families of the mentally disabled in Japan].

In order to evaluate a public health center based educational approach for families of the mentally disabled, questionnaires were sent to all public health centers in Japan. Out of 852 public health centers, 742 responded satisfactorily. At 68.6% of the 742 public health centers, some form of educational programs for families of the mentally disabled have been conducted. In a structured educational program, public health nurses and mental health counselors participated as the main staff. Training seminars for the staff were conducted by prefectural mental health centers or Zenkaren, The National Federation of Families with the Mentally Ill. In order to develop an educational program at the public health centers, the following three elements are required: 1) information transmitted through training seminars and publications, 2) trained staff members including mental health welfare counselors and public health nurses specialized in mental health, and 3) a sufficient budget. Further development of the program is considered crucial for a functional improvement of the public health centers.

Community Health Centers↗