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S Tanaka

Publications and source records attributed to S Tanaka.

At least 325 records · Page 18Linked to original sources
PubMed2001

Pathogenesis of the gradually elongated nerve.

The rabbits' sciatic nerves were lengthened by 30 mm in increments of 2.0 mm/day (2-mm group) and 4.0 mm/day (4-mm group). In the 2-mm group, the phosphorylated neurofilament (p-NF) immunoreactivity of axons was similar to that of the control group. However, in the 4-mm group, number of p-NF positive axons decreased. The number of p-NF positive cells at the seventh lumbar dorsal root ganglion cells of the 4-mm group was significantly larger than that of the control group. Abnormal p-NF immunoreactivity in the 4-mm group suggested an impairment of the axonal flow. Leakage of Evans blue-albumin into the endoneurial space, which meant destruction of the blood-nerve barrier function, was clearly evident in the 4-mm group, but minor in the 2-mm group. A speed of 2.0 mm/day, therefore, appears to be critical for safe nerve elongation in this model.

Animals↗
PubMed2001

Molecular analysis of plasma alpha 1,3-fucosyltransferase deficiency and development of the methods for its genotyping.

Four patients with mental illness were found to be deficient in plasma alpha1,3-fucosyltransferase for the first time in Japan [Exp Clin Immunogenet 1999;16:125-130]. Complete sequencing of FUT6 genes in these individuals revealed the presence of two point mutations, i.e., G739 to A (Glu-->247 to Lys) and C945 to A (Tyr-->315 to stop). In addition to two reported alleles having G739 to A (pf1) and G739 to A and C945 to A (pf3), a new mutated allele having C945 to A (pf2) was found to be present and all the individuals who lack alpha1,3-fucosyltransferase activity in plasma were found to possess pf genes homozygously (pf/pf). In order to detect such lethal mutations in FUT6 genes easily, PCR-RFLP methods have also been developed and applied for the screening of FUT6 deficiency in a large number of samples which resulted in the demonstration of three additional FUT6-deficient individuals. The absence of alpha1,3-fucosylated molecules on alpha(1)-acid glycoprotein in plasma from all the 7 individuals was confirmed to result from the plasma alpha1,3-fucosyltransferase deficiency.

Animals↗
PubMed2001

Dermoid cyst of the colon.

Dermoid cysts are benign cystic teratomas lined by skin and epidermal appendages. We report a dermoid cyst occurring in a 26-year-old female whose chief complaint was irregular vaginal bleeding. Abdominal magnetic resonance image demonstrated a space-occupying lesion in the right lower abdomen. The mass showed hyperintensity on the T2 image and the signal was homogeneous for the interior. During abdominal surgery we made the diagnosis of subserous tumor of the colon and resected the ileocecal portion of the colon. The tumor measured 5.4 x 4.8 x 3.5 cm and was soft and elastic. On cross section, a unilocular cyst filled with atheromatous material was found. Pathological examination revealed a dermoid cyst. In the view of this diagnosis, a simple excision would have been an adequate treatment.

Adult↗
PubMed2001

Clinical significance of human erythrocyte glucose transporter 1 expression at the deepest invasive site of advanced colorectal carcinoma.

OBJECTIVE: Malignant cells exhibit increased glucose uptake and utilization in vitro and in vivo. This process is thought to be mediated by the glucose transporter (Glut) family. The aim of this study was to elucidate the clinical significance of Glut1 expression at the site of deepest invasion as a predictor of the invasive/metastatic potential and prognosis of advanced colorectal carcinoma (CRC). METHODS: One hundred and fifty-two patients who had undergone surgical resection for advanced CRC were entered in this study. Histologic subclassifications at the deepest invasive site included well-differentiated (W), moderately to well-differentiated (Mw), moderately to poorly differentiated (Mp), poorly differentiated (Por) and mucinous (Muc) adenocarcinomas. Glut1 expression was examined immunohistochemically with a labeled streptavidin-biotin kit using anti-Glut1 polyclonal antibody MYM. As a marker of cell proliferation, Ki-67 expression was also examined. All immunoreactivity was analyzed at the deepest invasive site, central portion and superficial part. The immunohistochemical expression of Glut1 was defined as positive if distinct staining of the membrane or cytoplasm was observed in at least 30% of tumor cells. RESULTS: Glut1 expression was detected in 56 of 152 lesions (36.8%) at the deepest invasive site. The incidence of Glut1 expression at the deepest invasive site correlated significantly with histologic grade (W/Mw grade, 28% vs. Mp/Por/Muc grade, 48%), depth of invasion (invasion of muscularis propria/invasion of subserosa or subadventitia, 29% vs. invasion of serosa or adventitia/invasion of adjacent structures, 52%), lymphatic invasion (absence of lymphatic invasion, 19% vs. presence of lymphatic invasion, 40%), lymph node metastasis (absence of lymph node metastasis, 25% vs. presence of lymph node metastasis, 41%) and Duke's stage (Duke's <D, 32% vs. Duke's D, 51%). In the central portion and superficial part, there were no significant differences between Glut1, Ki-67 expression and clinicopathological findings. Glut1 expression at the deepest invasive site correlated significantly with the Ki-67 labeling index. In cases of curative surgery, patients with Glut1-positive lesions at the deepest invasive site showed a significantly poorer prognosis than those with Glut1-negative lesions. Multivariate analysis with logistic regression for 5-year survival in patients who had undergone curative surgery showed that lymph node metastasis and Glut1 expression were significant risk factors. CONCLUSION: These results indicate that Glut1 expression at the deepest site of tumor invasion can be a useful predictor of a high malignant potential and poor prognosis in advanced CRC.

Adenocarcinoma↗
PubMed2001

Genetic alterations in the human Tcf-4 gene in Japanese patients with sporadic gastrointestinal cancers with microsatellite instability.

Disruption of the APC/beta-catenin/Tcf pathway has been proposed as an important step in the development of cancer. The Tcf-4 transcription factor gene was reported to be one of the targets of microsatellite instability (MSI) in colorectal cancers in with MSI. We carried out a sequencing analysis of the Tcf-4 gene in 41 Japanese patients with gastrointestinal tumors with MSI as well as in cancer cell lines. Three of 21 (14.3%) colorectal tumors with MSI contained a mutant Tcf-4 gene encoding 1-bp deletion in an (A)9 repeat, leading to carboxyl terminal truncation of Tcf-4 protein. No Tcf-4 mutations were detected in 20 gastric tumors with MSI, or in gastric cancer cell lines. Additionally, we found a novel transcript of the Tcf-4 gene which contained a segment of 73 bp in front of the (A)9 repeat of the Tcf-4 coding sequence. Sequencing analysis revealed that the inserted fragment was 60% homologous to that of exon IXA of the Tcf-1 gene. It is of interest that this insertion resulted in truncation of Tcf-4, similar to the 1-bp deletion in the (A)9 repeat. Therefore, in part of the Japanese colorectal tumors with MSI, frameshift mutations in Tcf-4 may be of functional significance. Functional alterations in the Tcf-4 signaling network in gastrointestinal tumorigenesis require further investigations.

Adenocarcinoma↗
PubMed2001

Immunocytochemical localization of secretory phospholipase A(2)-like protein in the pituitary gland and surrounding tissue of the bullfrog, Rana catesbeiana.

Previously, we obtained a protein that has considerable amino acid sequence homology with secretory phospholipase A(2) (PLA(2)) from a bullfrog pituitary fraction obtained during the purification of thyrotropin (TSH). Subsequently, partial amino acid sequence (N-terminal 45 amino acid residues) analysis revealed this protein to be identical to the N-terminal amino acid sequence of otoconin-22, the major protein of aragonitic otoconia in the Xenopus saccule. In this study we developed an antibody against the N-terminal peptide of the bullfrog protein and applied it for immunocytochemical study of the pituitary and its surrounding tissue. Western blotting analysis showed that this antibody recognizes a 20.4-kD protein that has a molecular mass close to that of otoconin-22. Immunohistochemical reaction with the antibody was not found in any anterior pituitary cells but was intense in the monolayer epithelial cells of the endolymphatic sac surrounding the pituitary gland, which is a major storage site of calcium carbonate in amphibians. An electron microscopic study revealed that the cuboidal cells in the endolymphatic sac contained large, polymorphic secretory granules in their apical cytoplasm. Immunogold particles indicating the presence of a PLA(2)-like protein were observed predominately in these secretory granules. These findings support the view that this PLA(2)-like protein obtained during purification of TSH was derived from the endolymphatic sac adhering to the pituitary and that this protein is a bullfrog otoconin. (J Histochem Cytochem 49:631-637, 2001)

Animals↗
PubMed2001

Dietary phosphorus restriction reverses the impaired bone mineralization in vitamin D receptor knockout mice.

Deficiency of vitamin D, which is required for calcium homeostasis, causes rickets with hypocalcemia and hypophosphatemia, resulting in growth retardation and impaired bone formation. Mice lacking the vitamin D receptor (VDR) develop the typical features of rickets, establishing that VDR plays a role in controlling the actions of vitamin D. Normalization of impaired mineral homeostasis in VDR KO mice fed a diet supplemented with high concentrations of calcium (2%) and phosphorus (1.25%) is reported to reverse the malformation of bone and the growth retardation as well. However, the relationship between mobilization of phosphorus and calcium and nuclear control of vitamin D actions remains unclear. The present study was undertaken to determine the effect of dietary phosphorus on mineral mobilization and bone mineralization. We report here that feeding a diet supplemented with a restricted amount of phosphorus (0.25%) and a normal amount of calcium (0.5%) for 4 weeks reverses the growth retardation and the impaired mineralization in VDR KO mice, as does a high-calcium and high-phosphorus diet (Ca: 2%; P: 1.25%). Thus, the present study suggests that mobilization of calcium and mobilization of phosphorus are differentially regulated through vitamin D-dependent and -independent systems, and that intake of calcium and phosphorus in the proper ratio is important for mineral homeostasis and bone mineralization.

Animals↗
PubMed2001

DNA methylation regulates placental lactogen I gene expression.

Expression of rat placental lactogen I is specific to the placenta and never expressed in other tissues. To obtain insight into the mechanism of tissue-specific gene expression, we investigated the methylation status in 3.4 kb of the 5'-flanking region of the rat placental lactogen I gene. We found that the distal promoter region of the rat placental lactogen I gene had more potent promoter activity than that of the proximal area alone, which contains several possible cis-elements. Although there are only 17 CpGs in the promoter region, in vitro methylation of the reporter constructs caused severe suppression of reporter activity, and CpG sites in the placenta were more hypomethylated than other tissues. Coexpression of methyl-CpG-binding protein with reporter constructs elicited further suppression of the reporter activity, whereas treatment with trichostatin A, an inhibitor of histone deacetylase, reversed the suppression caused by methylation. Furthermore, treatment of rat placental lactogen I nonexpressing BRL cells with 5-aza-2'-deoxycytidine, an inhibitor of DNA methylation, or trichostatin A resulted in the de novo expression of rat placental lactogen I. These results provide evidence that change in DNA methylation is the fundamental mechanism regulating the tissue-specific expression of the rat placental lactogen I gene.

Animals↗
PubMed2001

Hypoadiponectinemia in obesity and type 2 diabetes: close association with insulin resistance and hyperinsulinemia.

Plasma concentrations of adiponectin, a novel adipose-specific protein with putative antiatherogenic and antiinflammatory effects, were found to be decreased in Japanese individuals with obesity, type 2 diabetes, and cardiovascular disease, conditions commonly associated with insulin resistance and hyperinsulinemia. To further characterize the relationship between adiponectinemia and adiposity, insulin sensitivity, insulinemia, and glucose tolerance, we measured plasma adiponectin concentrations, body composition (dual-energy x-ray absorptiometry), insulin sensitivity (M, hyperinsulinemic clamp), and glucose tolerance (75-g oral glucose tolerance test) in 23 Caucasians and 121 Pima Indians, a population with a high propensity for obesity and type 2 diabetes. Plasma adiponectin concentration was negatively correlated with percent body fat (r = -0.43), waist-to-thigh ratio (r = -0.46), fasting plasma insulin concentration (r = -0.63), and 2-h glucose concentration (r = -0.38), and positively correlated with M (r = 0.59) (all P < 0.001); all relations were evident in both ethnic groups. In a multivariate analysis, fasting plasma insulin concentration, M, and waist-to-thigh ratio, but not percent body fat or 2-h glucose concentration, were significant independent determinates of adiponectinemia, explaining 47% of the variance (r(2) = 0.47). Differences in adiponectinemia between Pima Indians and Caucasians (7.2 +/- 2.6 vs. 10.2 +/- 4.3 microg/ml, P < 0.0001) and between Pima Indians with normal, impaired, and diabetic glucose tolerance (7.5 +/- 2.7, 6.1 +/- 2.0, 5.5 +/- 1.6 microg/ml, P < 0.0001) remained significant after adjustment for adiposity, but not after additional adjustment for M or fasting insulin concentration. These results confirm that obesity and type 2 diabetes are associated with low plasma adiponectin concentrations in different ethnic groups and indicate that the degree of hypoadiponectinemia is more closely related to the degree of insulin resistance and hyperinsulinemia than to the degree of adiposity and glucose intolerance.

Adiponectin↗
PubMed2001

Weight reduction increases plasma levels of an adipose-derived anti-inflammatory protein, adiponectin.

Adiponectin, an adipose tissue-specific plasma protein, was recently revealed to have anti-inflammatory effects on the cellular components of vascular wall. Its plasma levels were significantly lower in men than in women and lower in human subjects with obesity, type 2 diabetes mellitus, or coronary artery disease. Therefore, it may provide a biological link between obesity and obesity-related disorders such as atherosclerosis, against which it may confer protection. In this study, we observed the changes of plasma adiponectin levels with body weight reduction among 22 obese patients who received gastric partition surgery. A 46% increase of mean plasma adiponectin level was accompanied by a 21% reduction in mean body mass index. The change in plasma adiponectin levels was significantly correlated with the changes in body mass index (r = -0.5, P = 0.01), waist (r = -0.4, P = 0.04) and hip (r = -0.6, P = 0.0007) circumferences, and steady state plasma glucose levels (r = -0.5, P = 0.04). In multivariate linear regression models, the increase in adiponectin as a dependent variable was significantly related to the decrease in hip circumference (beta = -0.16, P = 0.028), after adjusting body mass index and waist circumference. The change in steady state plasma glucose levels as a dependent variable was related to the increase of adiponectin with a marginal significance (beta = -0.92, P = 0.053), after adjusting body mass index and waist and hip circumferences. In conclusion, body weight reduction increased the plasma levels of a protective adipocytokine, adiponectin. In addition, the increase in plasma adiponectin despite the reduction of the only tissue of its own synthesis suggests that the expression of adiponectin is under feedback inhibition in obesity.

Adiponectin↗
PubMed2001

Allelotyping of follicular thyroid carcinoma: frequent allelic losses in chromosome arms 7q, 11p, and 22q.

The genetic mechanisms involved in development of follicular thyroid carcinoma are poorly understood, although allelic losses (LOH) in this type of tumor have been reported in small panels of follicular thyroid carcinomas examined in earlier studies. To clarify the real frequency of allelic loss we carried out a genome-wide allelotyping study of 66 follicular thyroid carcinomas using 39 microsatellite markers representing all nonacrocentric autosomal arms. The mean frequency of LOH was 9.2%, and the mean fractional allelic loss was 0.09. The most frequent allelic losses were detected in 7q (28%), 11p (28%), and 22q (41%). When we compared these results with our previous allelotyping studies using identical markers in other types of thyroid cancers, the 9.2% mean frequency of allelic loss detected in follicular thyroid carcinomas was higher than that in papillary thyroid carcinomas (3%), but not as high as that detected in anaplastic thyroid carcinomas (20%). Frequent allelic losses of markers on chromosomes 7q, 11p, and 22q suggest locations to examine for the presence of suppressor genes associated with the development of follicular thyroid carcinoma.

Adenocarcinoma, Follicular↗
PubMed2001

The genetic basis of plasma variation in adiponectin, a global endophenotype for obesity and the metabolic syndrome.

Here we present the first genetic analysis of adiponectin levels, a newly identified adipocyte-derived protein. Recent work has suggested that adiponectin may play a role in mediating the effects of body weight as a risk factor for coronary artery disease. For this analysis we assayed serum levels of adiponectin in 1100 adults of predominantly northern European ancestry distributed across 170 families. Quantitative genetic analysis of adiponectin levels detected an additive genetic heritability of 46%. The maximum LOD score detected in a genome wide scan for adiponectin levels was 4.06 (P = 7.7 x 10(-6)), 35 cM from pter on chromosome 5. The second largest LOD score (LOD = 3.2; P = 6.2 x 10(-5)) was detected on chromosome 14, 29 cM from pter. The detection of a significant linkage with a quantitative trait locus on chromosome 5 provides strong evidence for a replication of a previously reported quantitative trait locus for obesity-related phenotypes. In addition, several secondary signals offer potential evidence of replications for additional previously reported obesity-related quantitative trait loci on chromosomes 2 and 10. Not only do these results identify quantitative trait loci with significant effects on a newly described, and potentially very important, adipocyte-derived protein, they also reveal the emergence of a consistent pattern of linkage results for obesity-related traits across a number of human populations.

Adiponectin↗
PubMed2001

Nociception and allodynia/hyperalgesia induced by intrathecal administration of fenvalerate.

The intrathecal injection of fenvalerate, a sodium channel activator, at doses of 0.01 to 3 microg, dose-dependently induced the duration of a characteristic behavioral syndrome mainly consisting of reciprocal hind limb scratching directed towards caudal parts of the body and biting or licking of the hind legs in mice. Fenvalerate-induced behavior was inhibited by morphine (1-10 mg/kg, i.p.). The characteristic behavior was also inhibited by mexiletine, a sodium channel blocker; MK-801, a N-methyl-D-aspartate ion-channel blocker; and GR82334, a neurokinin-1-receptor antagonist. Calphostin C (3 pmol, i.t.), a protein kinase C inhibitor, inhibited fenvalerate-induced behavior. On the other hand, phorbol-12, 13-dibutyrate (50 pmol, i.t.), a protein kinase C activator, markedly enhanced the fenvalerate-induced behavior. The present results also showed that fenvalerate produced thermal allodynia and hyperalgesia in the tail-flick test. Furthermore, fenvalerate-induced thermal allodynia and hyperalgesia were inhibited by the pretreatment with calphostin C. These results suggest that the intrathecal administration of fenvalerate induces a marked nociceptive response and thermal allodynia/hyperalgesia, and they suggest that tetrodotoxin-resistant sodium channels may play an important role in this effect.

Animals↗
PubMed2001

Aurantiamide acetate, a selective cathepsin inhibitor, produced by Aspergillus penicilloides.

Aurantiamide acetate was isolated from the fermentation broth of Aspergillus penicilloides for the first time. Aurantiamide acetate inhibited cysteine proteinases, in particular, cathepsin L (3.4.22.15) and B (3.4.22.1) with IC50 of 12 microM and 49 microM, respectively. In the adjuvant-arthritic rat model, subcutaneously administered 10 mg/kg body weight of this compound suppressed hind paw swelling.

Aspergillus↗
PubMed2001

[Blood vessels in normal and abnormal mitral valve leaflets].

UNLABELLED: The incidence and the distribution of blood vessels were examined in normal and abnormal mitral valve leaflets. MATERIALS AND METHODS: Normal valves were obtained from 12 autopsy cases without cardiovascular disease (8 men, 4 women, 33 to 93 years of age). Twenty-one abnormal valves were obtained at the time of mitral valve replacement (12 men, 9 women, 16 to 78 years of age). Clinical and pathological diagnoses were rheumatic valvular disease (RVD: n=8), floppy mitral valve (FMV: n=9), and healed infective endocarditis (HIE: n=4, 1 with RVD, 3 with FMV). The number of vessels was counted at the surgical excision line of the valvular rings by immunohistochemical study using Factor VIII related antigen and CD34. Histologic studies were also made at the 5 mm distal line from the ring in normal valves, and at the vertical line to the ring in abnormal valves. RESULTS: In normal valves, the number of vessels at the ring area, except in myocardial tissues that extended from the left atrium to the auricularis, ranged from 3 to 184. Vessels were also found at the 5 mm distal area from the ring in 6 valves out of 12. Vessels were mainly distributed near the commissure areas of the auricularis and/or the spongiosa and were extended with myocardial tissues. There was no difference in the number of vessels related to age or sex. In RVD, the number of vessels at the ring area ranged from 22 to 517 in 8 anterior leaflets (AML) and 2 to 151 in 5 posterior leaflets (PML). Many vessels also appeared in the distal spongiosa of the leaflets, and arterioles were frequently found in these areas. In FMV, a few (3 and 6) vessels were found in 2 leaflets (AML: 2/8, PML: 0/4). In HIE, the number of vessels was 216 in the case with RVD, and 3 to 110 in cases with FMV. CONCLUSION: At the ring area, normal mitral valve leaflets were supplied with nutrition from blood vessels that mainly extended from the left atrium with myocardial tissues. In RVD, the vessels branched from previously existing capillaries, extending to the distal area, and increased in number. Mechanical stress during opening and closing of the leaflets contributes to the arterialization of these vessels. In FMV, the number of capillaries, which is smaller than in normal valves, might be related to the progression of this disorder. In HIE with valvular disease, the number of vessels is related to the preexisting disease.

Adult↗
PubMed2001

High survival rate of 6 cases of pulmonary large cell neuroendocrine carcinoma formerly classified as small cell carcinoma.

UNLABELLED: In the revised WHO classification of lung cancer, published in 1999, large cell neuroendocrine carcinoma (LCNEC) was employed as a new histological entity. LCNEC is generally considered a high-grade malignant lung cancer, and appropriate treatment remains to be determined. Before its new classification, LCNEC had long been classified into several entities. Advancing the review of previous cases in Nippon Medical School Hospital, we noticed that some LCNEC patients were formally diagnosed as having small cell lung cancer (SCLC), and they showed long-term survival. MATERIAL AND METHODS: All histological specimens of surgically resected SCLC in Nippon Medical School Hospital were reclassified according to the 1999 WHO classification manual. Their neuroendocrine differentiations were confirmed by the use of immunostainings with chromogranin A and synaptophysin. RESULTS: Fourteen cases satisfied the qualifications for both histological and clinical reevaluation. Among them, 6 patients were reclassified as LCNEC, and their stage distribution was as follow: IA; 1, IB; 2, IIIA; 2, and IIIB; 1. Their survival term ranged from 33.8 to 78.0 months; 5 were still alive, and 1 (IIIB) died 57.6 months after surgery. DISCUSSION: According to this study, all the LCNEC patients who were treated as SCLC patients showed more favorable prognoses than patients described in published studies, even overall lung cancer. Therefore, it is suggested that multimodality therapy for SCLC may improve the prognoses of patients with LCNEC.

Aged↗