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Biomedical subjects

S Tamura

Publications and source records attributed to S Tamura.

At least 73 records · Page 4Linked to original sources
PubMed2001

The correlation between 99mTc-MIBI uptake and MIB-1 as a nuclear proliferation marker in glioma--a comparative study with 201Tl.

Technetium-99m methoxy-isobutylisonitrile (MIBI), like thallium-201 (201Tl), is a highly efficient agent for the diagnosis and monitoring of glioma tumors. Although 201Tl uptake is known to be partly associated with proliferative activity, little is known about the correlation between MIBI uptake and proliferation activity in gliomas. The current study was performed to assess the correlation between MIBI uptake and proliferative activities in gliomas, estimated by the monoclonal antibody to Ki-67 antigen (MIB-1) staining method. By comparing the results with those of 201Tl, we determined which tracer would be suitable for estimating proliferative activities. Twenty-four presurgical glioma patients (six with low-grade gliomas, five with anaplastic astrocytomas, and 13 with glioblastomas) were given MIBI and 201Tl SPECT. Early (10 min after injection) and delayed images (3 h after injection) were obtained for both MIBI and 201Tl scintigraphy. SPECT parameters, early ratio (ER), delayed ratio (DR), and retention index (RI) were obtained in both radiopharmaceuticals. All patients underwent subsequent surgical excision, and the specimens were immunostained for MIB-1. The proliferative activity was measured as a percentage positive nuclear area for MIB-1 (MI; MIB-1 index). To evaluate the relationship between the proliferative activity and SPECT parameters, we performed a correlation analysis. MI correlated with the MIBI uptake ratio (r = 0.75 for ER, and r = 0.7 for DR). Both DR and RI of 201Tl also correlated with MI, but weakly (r = 0.6 for DR, and. r = 0.59 for RI). There was no significant correlation between the MIB-1 index and the other parameters. MIBI-uptake parameters demonstrated a stronger positive correlation with the MIB-1 index than that of 201Tl. With the use of MIBI SPECT, we can estimate the proliferative activity of glioma noninvasively.

Adolescent↗
PubMed2001

MR-based three-dimensional presentation of cartilage thickness in the femoral head.

The purpose of our study was to visualize the hyaline cartilage of the femoral head and to evaluate the distribution of the thickness by three-dimensional reconstruction of MRI data. The MRI was performed in 10 normal volunteers, 1 patient with osteonecrosis and 4 with advanced osteoarthritis. A fast 3D spoiled gradient-recalled acquisition in the steady state pulse sequence (TR 22 ms/TE 5.6 ms/no. of excitations 2) with fat suppression was used for data collection. Coronal and sagittal images were obtained with 3-mm effective slice thickness, 16-cm field of view (FOV) and 256x192 matrix. The MR images were reconstructed in three dimensions for evaluating the distribution of the cartilage thickness. In all normal volunteers, 1 patient with osteonecrosis and three advanced osteoarthritis, 3D reconstruction was successful, but in 1 case of osteoarthritis, 3D reconstruction failed because of the narrow joint space. In normal volunteers, the cartilage thickness is thickest in the central portion around the ligamentum teres (mean 2.8 mm). The medial portion and the lateral portion are almost of the same thickness (medial 1.3 mm, lateral 1.1 mm). In 3 cases of osteoarthritis, the cartilage became thinner in the lateral portions (<0.6 mm), but was unchanged in the central and medial portions. Three-dimensional reconstruction of MRI data is useful for evaluating the distribution of the cartilage thickness of the femoral head objectively.

Adult↗
PubMed2001

The peroxin Pex6p gene is impaired in peroxisomal biogenesis disorders of complementation group 6.

Human genetic peroxisomal biogenesis disorders (PBDs), such as Zellweger syndrome, comprise 13 different complementation groups (CGs). Eleven peroxin genes, termed PEXs, responsible for PBDs have been identified, whereas pathogenic genes for PBDs of 2CGs, CG-A (the same CG as CG8 in the United States and Europe) and CG6, remained unidentified. We herein provide several lines of novel evidence indicating that PEX6, the pathogenic gene for CG4, is impaired in PBD of CG6. Expression of PEX6 restored peroxisome assembly in fibroblasts from a CG6 PBD patient. This patient was a compound heterozygote for PEX6 gene alleles. Accordingly, by merging CG6 with CG4, human PBDs are now classified into 12CGs.

ATPases Associated with Diverse Cellular Activitie↗
PubMed2001

Computerized classification of interstitial lung abnormalities on chest radiographs with normalized radiographic index and normalized fractal dimension.

OBJECTIVE: To evaluate the performance of two kinds of physical measures, the normalized radiographic index (R) and the normalized fractal dimension (F), for computerized classification of interstitial lung abnormalities on chest radiographs. METHODS AND MATERIAL: The values of R were obtained as the normalized percent area of extracted opacities in selected regions of interest (ROIs). The values of F were calculated with a box-counting algorithm and then normalized. To extract linear opacities on chest radiographs selectively, we processed ROIs by four-directional Laplacian-Gaussian filtering and binarization (4LG/B), linear opacity judgment (LOJ), and linear opacity subtraction (LOS). We used the ROIs of 50 mild and 50 severe interstitial lung abnormalities. In both groups, all cases were divided into H (n=21, honeycombing opacities were found to be dominant) and Non-H (n=79, abnormal opacities were found, but these were excluded from H). We obtained three types of normalized physical measures of R and F in one ROI from 4LG/B, LOJ, and LOS images, and the combined indices, R(COM) and F(COM) were calculated. RESULTS: The values of F(LOJ) could differentiate H from Non-H in the mild-and the severe-abnormality group. However, all Rs could not differentiate H from Non-H in the severe-abnormality group. The combined indices of both R and F could differentiate H from Non-H in the mild-abnormality group; however, these could not differentiate H from Non-H in the severe-abnormality group. CONCLUSION: The values of F(LOJ) seem to be useful in the classification of interstitial lung abnormalities on chest radiographs.

Fractals↗
PubMed2001

The effects of transplantation of osteoblastic cells with bone morphogenetic protein (BMP)/carrier complex on bone repair.

We investigated the effects of transplantation of osteoblastic cells with a bone morphogenetic protein (BMP)/carrier complex on bone repair by in vitro and in vivo experiments. Poly-D,L-lactic-co-glycolic acid/gelatin sponge (PGS) was used as a carrier for cell transplantation. In the in vitro experiments, three cell types, C3H10T1/2 cells, MC3T3-E1 cells, and primary osteoblastic cells, isolated from newborn rat calvariae (ROB cells), were cultured for 2 weeks on PGS alone or PGS containing BMP-2 (PGS/BMP). C3H10T1/2 cells cultured on PGS/BMP expressed several markers related to differentiation of both osteoblasts and chondrocytes, such as alkaline phosphatase (ALP) activity and mRNAs for osteocalcin and aggrecan, whereas the cells cultured on PGS alone expressed no such markers. MC3T3-E1 cells cultured on PGS/BMP exhibited a more ALP-positive cells than those cultured on PGS alone. PGS/BMP promoted ROB cell differentiation into both osteoblasts and chondrocytes. In the in vivo experiments, we transplanted ROB cells, which had been cultured on PGS alone or PGS/BMP in vitro for 2 weeks, into bone defects created in rat calvariae. Transplantation of ROB cells cultured on PGS alone generated little new bone. Transplantation of ROB cells cultured on PGS, which absorbed a low dose (10 ng) of rhBMP-2,; induced significantly higher bone mineral content than PGS/BMP alone, although application of a high dose (1 microg) of rhBMP-2 induced no difference in bone mineral content between transplantation of PGS/BMP with or without ROB cells. These results show that transplantation of osteoblastic cells after induction of osteoblast maturation in vitro by cultivation on PGS/BMP is a potent technique for cell therapy of bone repair.

Aggrecans↗
PubMed2001

Transient global amnesia (TGA) in an MEG study.

A patient who had experienced an attack of transient global amnesia (TGA) was examined using neurophysiological methods. Magnetoencephalography (MEG) was performed and the Wechsler Memory Scale-Revised (WMS-R) test was administered at 5 days and at more than a month after the TGA episode. MEG data on neuronal activity obtained while the patient was undertaking a working memory task and during rest were analyzed using the wavelet-crosscorrelation method, which reveals time-lag and information flow between related sites in the brain. The WMS-R memory scores showed dramatic improvement when the test was administered a month following the attack, although no significant changes were observed in EEG, MRI and SPECT data. The MEG study revealed that under a working memory load how the neuron works functionally and the information propagates assembly within the right hemisphere, and that these brain functions were not performed adequately shortly after the TGA attack.

Amnesia, Transient Global↗
PubMed2001

Lymph node metastasis along the recurrent nerve chain is an indication for cervical lymph node dissection in thoracic esophageal cancer.

This study examined whether recurrent nerve chain node metastasis serves as an indicative factor for cervical lymph node dissection in thoracic esophageal cancer. The association of recurrent nerve chain lymph node metastasis and cervical node metastasis was analyzed for 91 patients with thoracic esophageal cancer who had undergone three-field lymph node dissection. In patients with upper thoracic esophageal cancer, the incidence of cervical lymph node metastasis was similar regardless of recurrent nerve chain node metastasis. On the other hand, in patients with middle or lower esophageal cancer, the incidence was significantly higher in recurrent nerve-positive (16/31, 51.6%) than in recurrent nerve-negative (5/43, 11.6%) patients. The prognosis of patients with recurrent nerve chain node metastasis was significantly better in the three-field dissection group than in the two-field dissection group, while in patients with no recurrent nerve chain node metastasis, survival was similar between the two groups. In conclusion, cervical lymphadenectomy can be omitted for recurrent nerve chain node-negative patients with middle and lower thoracic esophageal cancer.

Abdomen↗
PubMed2001

Evaluation of endoscopic and histopathological features of serrated adenoma of the colon.

BACKGROUND AND STUDY AIMS: The aim of this study was to reveal the clinical features of serrated colonic adenoma by investigating its endoscopic features using a magnifying videoscope. MATERIALS AND METHODS: 68 colorectal serrated adenomas presented for colonoscopic examination were included in this study. A magnifying videoscope with a zoom ranging from x 1 to x 100 magnification was employed to observe the pit patterns of colonic lesions, and 39 of the serrated adenoma specimens were evaluated using this. Some pit patterns appeared as elongated oval and stellar-like orifices of the crypts; we termed these type which was detected III(SA) patterns. Other pit patterns showed a flower petal-like or pineal form, and this was termed a type IV(SA) pit pattern. RESULTS: In the entire sample of serrated adenomas, 53 were of the protruded type, and 15 were superficial, for a protruded/superficial ratio of 3.5 : 1. The protruded type of serrated adenoma predominated in the distal portion. The superficial type was preferentially located in the proximal portion of the colon (P < 0.0001). Among the 13 superficial types in which the magnifying videoscope was used, all 13 showed the type III(SA) basic pit pattern. In these serrated adenomas of the superficial type, an additional IV(SA) pit pattern was found in 23.1% (3/13), which was detected in 53.8% (14/26) in the protruded type. Small serrated adenomas measuring less than 10 mm in diameter were preferentially mild to moderate atypia (odd's ratio = 15.9, P = 0.0216). CONCLUSION: The pit pattern may prove useful for the endoscopic diagnosis of serrated adenoma. Furthermore, endoscopic treatment is indicated for serrated adenoma; in particular those of 10 mm or more in diameter should be treated because of the possibility of high-grade glandular intraepithelial neoplasia.

Adenoma↗
PubMed2001

Comparison and evolution of the lagena in various animal species.

The structure of the vestibular organs of the teleost fish (bluegill), newts (Japanese fire-belly newt), frogs (black-spotted pond frog), snapping turtles and birds (chicks) was morphologically compared, with particular attention to the lagena macula, and the differences between animal species with relation to evolution were considered. Teleost fish had no striola on the lagena macula. The striola of newts were short and restricted to the central area of the macula, but those of frogs, snapping turtles and chicks extended from the anterior to posterior edges of the macula. This indicates that the frog is more highly evolved than the newt. The length of the kinocilium of sensory hairs was equal to that of the longest stereocilium in teleost fish and newts, but the kinocilia of frogs, snapping turtles and chicks were longer than the longest stereocilium. This indicates that the function of the lagena of teleost fish and newts is for hearing whilst in the other animals they are for posture. The diameter of the sensory hair bundles is small in teleost fish and frogs, but large in newts and snapping turtles. This indicates that the sensitivity of the sensory cells of the lagena towards outer force is low in teleost fish and frogs, high in newts and snapping turtles and intermediate in birds. The lagena of snapping turtles protrudes from the basilar papilla into the vestibule but the lagena of chicks lies on the tip of the long projecting basilar papilla. From observation of the locations of lagenae it is natural to speculate that there must have been some species of animal now extinct that had the evolving location of the lagena prior to that of chicks. In future it will be very interesting and useful to identify this extinct animal using DNA techniques.

Acoustic Maculae↗
PubMed2001

Advanced peritonitis and subclinical disseminated intravascular coagulopathy associated with Chlamydia trachomatis infection.

A 29-y-old woman was admitted to our hospital complaining of slight fullness of the lower abdomen. Ultrasound echographic study and magnetic resonance imaging showed pleural effusion and pelvic ascites. Laboratory investigation revealed anemia and thrombocytopenia (hemoglobin 6 mmol/l; platelets 7 x 10(10)/l), remarkable polyclonal hypergammopathy (gamma immunoglobulin 7.7 g/dl) and subclinical disseminated intravascular coagulopathy (DIC). By laparoscopy, extensive adhesion of the peritoneum and bilateral ovarian tubes was observed. From the appearance of adhesion, we suspected Chlamydia trachomatis infection and performed serologic and molecular studies. Administration of clarithromycin resolved hypergammopathy, DIC and ascites.

Adult↗
PubMed2001

Involvement of calcium ion in the stimulated shoot elongation of arrowhead tubers under anaerobic conditions.

Shoot elongation of arrowhead (Sagittaria pygmaea Miq.) tubers was stimulated in anaerobic conditions. The anaerobic elongation was attributed to stimulation of cell elongation in the middle of the shoots. The anaerobic elongation of the shoots was severely inhibited by ethylene glycol bis(beta-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA). The EGTA inhibition was completely nullified by exogenous CaCl2, which acts as an enhancer of anaerobic elongation. Moreover, calcium channel blockers, verapamil, diltiazem and LaCl3, inhibited the anaerobic elongation enhanced by CaCl2. These results showed that calcium plays an important role in stimulating the elongation in anaerobic conditions. Incorporation of 45Ca into the shoot tissues was measured to determine the involvement of calcium uptake in anaerobic elongation. Incorporation of 45Ca into the cell sap, which was collected from frozen and thawed shoots after thorough washing with LaCl3, was significantly stimulated in anaerobic conditions. Verapamil and diltiazem prevented the stimulation of 45Ca incorporation in anaerobic conditions. These results suggest that calcium uptake from the medium serves to enhance shoot elongation of arrowhead tubers under anaerobic conditions.

Anaerobiosis↗
PubMed2001

Correlation of beta-catenin and cyclin D1 expression in colon cancers.

OBJECTIVE: Beta-catenin activates transcription by TCF/LEF and has been regarded as an oncogene in a wide range of malignant tumors. Among various molecules regulated by beta-catenin/Tcf, cyclin D1 is the most likely candidate for stimulation of the oncogenic pathway. The association between beta-catenin and cyclin D1 was investigated using clinical samples from colorectal cancers. METHODS: The expression of beta-catenin and cyclin D1 was investigated by immunohistochemical analyses of samples from 70 patients with colorectal cancers. In 28 of the fresh tumor samples, beta-catenin protein was separated into soluble and insoluble fractions and quantitatively correlated with cyclin D1 protein by Western blot analysis. RESULTS: Compared with noncancerous epithelium, beta-catenin and cyclin D1 were overexpressed (+) in 35 (50%) and 30 cases (43%), respectively. Cyclin D1 (+) was observed in 74% (26/35) of beta-catenin (+) cases, but only in 11% (4/35) of the beta-catenin (-) cases. Thus, there was a strong association between the expression of beta-catenin and that of cyclin D1 (p < 0.001). In the Western blot analysis, the amount of cyclin D1 correlated well with beta-catenin expression in the soluble fraction (p = 0.0016), but not with beta-catenin in the insoluble fraction or with E-cadherin expression. Beta-catenin (-)/cyclin D1 (-) cases displayed less tumor invasion than the remaining cases. However, there were no significant differences in lymph node metastasis or other clinicopathological findings. CONCLUSION: Our results indicate that beta-catenin overexpression in the cytoplasm may promote malignant transformation by triggering cyclin D1 expression in colorectal cancers.

Adenocarcinoma↗
PubMed2001

Vascular endothelial dysfunction resulting from L-arginine deficiency in a patient with lysinuric protein intolerance.

Although L-arginine is the only substrate for nitric oxide (NO) production, no studies have yet been reported on the effect of an L-arginine deficiency on vascular function in humans. Lysinuric protein intolerance (LPI) is a rare autosomal recessive defect of dibasic amino acid transport caused by mutations in the SLC7A7 gene, resulting in an L-arginine deficiency. Vascular endothelial function was examined in an LPI patient who was shown to be a compound heterozygote for two mutations in the gene (5.3-kbp Alu-mediated deletion, IVS3+1G-->A). The lumen diameter of the brachial artery was measured in this patient and in healthy controls at rest, during reactive hyperemia (endothelium-dependent vasodilation [EDV]), and after sublingual nitroglycerin administration (endothelium-independent vasodilation [EIV]) using ultrasonography. Both EDV and NO(x) concentrations were markedly reduced in the patient compared with those for the controls. They became normal after an L-arginine infusion. EIV was not significantly different between the patient and controls. Positron emission tomography of the heart and a treadmill test revealed ischemic changes in the patient, which were improved by the L-arginine infusion. Thus, in the LPI patient, L-arginine deficiency caused vascular endothelial dysfunction via a decrease in NO production.

Adult↗
PubMed2001

Task-related signal decrease on functional magnetic resonance imaging.

An atypical pattern of signal change was identified on functional magnetic resonance (fMR) imaging in pathologic patients. Three normal volunteers and 34 patients with pathologic lesions near the primary motor cortex underwent fMR imaging with echo-planar imaging while performing a hand motor task. Signal intensities were evaluated with the z-score method, and the time course and changes of the signal intensity were calculated. Nine of the 34 patients with pathologic lesions displayed a significant task-related signal reduction in motor-related areas. They also presented a conventional task-related signal increase in other motor-related areas. The time courses of the increase and decrease were the inverse of each other. There was no significant difference between rates of signal increase and decrease. Our findings suggest that this atypical signal decrease is clinically significant, and that impaired vascular reactivity and altered oxygen metabolism could contribute to the task-related signal reduction. Brain areas showing such task-related signal decrease should be preserved at surgery.

Adolescent↗
PubMed2001

Pancreatic biopsy as a procedure for detecting in situ autoimmune phenomena in type 1 diabetes: close correlation between serological markers and histological evidence of cellular autoimmunity.

To better understand the pathogenesis of type 1 diabetes, we have developed pancreatic biopsy under laparoscope for recent-onset type 1 diabetic patients. The patients included 29 acute-onset type 1 diabetic patients, 5 latent-onset type 1 diabetic patients, and 1 type 2 diabetic patient. Their median age was 28 years, and the duration of diabetes at the time of biopsy was approximately 3 months. In 31 of 35 patients, we could obtain the pancreas tissue by punching. No serious complications, such as heavy bleeding, peritonitis, or pancreatitis, have been experienced. Pneumoderma was observed in two patients, and abdominal dull pain had continued for 2 days in two patients. However, special treatment was not necessary for these complications. T-cell-predominant infiltration to islets (insulitis) and hyperexpression of major histocompatibility complex class I antigens on islet cells were the two major findings and were observed in 17 of 29 recent-onset type 1 diabetic patients. These findings could be regarded as evidence of immune attack against beta-cells, and their presence was closely correlated with the presence of either anti-GAD or anti-IA-2 antibodies (P = 0.02). In conclusion, pancreatic biopsy under laparoscope is a safe procedure without serious complications, according to our findings, for detecting in situ autoimmune phenomenon in recent-onset type 1 diabetic patients.

Adolescent↗