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T Tachikawa

Publications and source records attributed to T Tachikawa.

At least 19 recordsLinked to original sources

Expression of protein kinases C betaI, betaII, and VEGF during the differentiation of enamel epithelium in tooth development.

Protein kinase C (PKC) is an important molecule involved in various cell function, and mediates induced secretion of vascular endothelial growth factor (VEGF). It is hypothesized that PKC and VEGF may be associated with tooth development. Using the laser microdissection method and real-time reverse-transcription-polymerase chain-reaction (RT-PCR), we investigated the expression of PKC betaI and betaII, VEGF, and amelogenin (used as a marker of differentiation to ameloblasts) in the inner and outer enamel epithelia, stellate reticulum, and dental papilla in each stage of the dental germ. We found that the expression levels of PKC betaI and betaII were increased in the inner enamel epithelium during the early bell stage. In addition, the increased expression levels of PKC betaI and betaII were accompanied by increased VEGF expression. These results indicate that PKC betaI, betaII, and VEGF are closely associated with the differentiation of the inner enamel epithelium to ameloblasts.

Ameloblasts↗

Redox state-dependent and sorbitol accumulation-independent diabetic albuminuria in mice with transgene-derived human aldose reductase and sorbitol dehydrogenase deficiency.

AIMS/HYPOTHESIS: We investigated the role played by sorbitol accumulation in the kidney in the development of diabetic albuminuria. METHODS: We created mice ( hAR-Tg:SDH null) with transgene-derived human aldose reductase and sorbitol dehydrogenase (SDH) deficiency, and analysed (i). the contribution of accumulated sorbitol to urinary albumin excretion rate, and (ii). the effect of the aldose reductase inhibitor, epalrestat, on the diabetic redox state, including decreased renal reduced glutathione concentrations or increased lactate to pyruvate ratios in the diabetic kidney. RESULTS: Compared to littermates, non-diabetic transgenic mice had a 2.6-fold increase in aldose reductase mRNA. In a diabetic group, aldose reductase mRNA in hAR-Tg mice was 2.7-fold higher than in littermates. In the diabetic and non-diabetic groups, hAR-Tg:SDH null mice had the highest sorbitol content among all four genetic types including hAR-Tg:SDH null, SDH null, hAR-Tg and littermates. The urinary albumin excretion rate in non-diabetic groups was similar in the four genetic types of mouse. In diabetic groups it was greater than in non-diabetic groups, but did not correlate with the sorbitol content among the four genetic types of mouse. When aldose reductase inhibitor and streptozotocin were given simultaneously at 6 weeks of age, epalrestat prevented diabetic increases in urinary albumin excretion rate and completely prevented diabetic decreases in reduced glutathione concentrations and diabetic increases in lactate to pyruvate ratios, even in the presence of transgenic aldose reductase. CONCLUSIONS/INTERPRETATION: The degree of diabetic albuminuria in genetically modified mice is dependent on the redox state and independent of polyol accumulation; aldose reductase inhibitor can prevent diabetic albuminuria by normalising diabetic redox changes.

Albuminuria↗

Malignant transformation of endometriosis and genetic alterations of K-ras and microsatellite instability.

OBJECTIVES: To clarify the role of specific genetic alterations in the multi-step process of malignant transformation of endometriosis. METHODS: In cases of ovarian endometrioid carcinoma, we separated regions of normal endometriosis, atypical endometriosis and ovarian endometrioid carcinoma by laser microdissection, and examined K-ras mutation and microsatellite instability in each separated tissue sample. RESULTS: We detected K-ras mutation and microsatellite instability in endometrioid carcinoma tissue, but not in normal or atypical endometriosis bordering the cancerous region. CONCLUSIONS: The present findings suggest that K-ras mutation and microsatellite instability are associated with malignant transformation from atypical endometriosis to ovarian endometrioid carcinoma.

Adult↗

Subcutaneous and continuous administration of lipopolysaccharide increases serum levels of triglyceride and monocyte chemoattractant protein-1 in rats.

OBJECTIVES: Previous studies have suggested an association between chronic infection and cardiovascular disease, and combined infection/inflammation is frequently related with hypertriglyceridemia, which may be a risk factor of cardiovascular disease. In fact, experimental transient or intermittent administration of lipopolysaccharide (LPS) is known to cause hypertriglyceridemia. We investigated the effects of subcutaneous and continuous administration of LPS in rats, which was considered to mimic chronic infection such as periodontal disease, on the serum levels of lipids [triglyceride (TG), total cholesterol (TC) and free fatty acid (FFA)] and cytokines [tumor necrosis factor-alpha (TNF-alpha) and monocyte chemoattractant protein-1 (MCP-1)], all of which are thought to be etiological factors of atherosclerotic cardiovascular disease. METHODS: Ten fasted Wistar rats were subcutaneously injected with LPS (500 micro g/100 g of body weight) (LPS-injected rats; n = 5) or saline (saline-injected rats; n = 5) as a model of transient infection. Further, mini-osmotic pumps containing the same concentration of LPS (LPS-implanted rats; n = 5) or saline (saline-implanted rats; n = 5) were subcutaneously implanted into an additional 10 rats as a model of chronic infection. After the injection or implantation, time-dependent changes in serum levels of TG, TC, FFA, TNF-alpha, MCP-1 and LPS were determined. RESULTS: LPS was detected in serum until 24 h in LPS-injected rats and until day 5 in LPS-implanted rats. Serum TG levels significantly increased from 6 to 24 h in LPS-injected rats and from day 5 to 14 in LPS-implanted rats. In both LPS-injected and LPS-implanted rats, serum FFA levels increased only slightly, whereas serum TC levels did not appreciably change. Both types of LPS administration increased serum TNF-alpha levels transiently and MCP-1 levels continuously. CONCLUSIONS: These findings suggest that chronic infection such as periodontal disease induces hypertriglyceridemia and increases serum MCP-1 levels in a manner that increases the risk of atherosclerotic cardiovascular disease.

Analysis of Variance↗

Gene expression profiling of mouse condylar cartilage during mastication by means of laser microdissection and cDNA array.

Little is known about the mechanisms of mandibular condylar growth. In this study, gene expression in the mandibular condylar cartilage of young post-natal mice was monitored by means of a cDNA microarray, real-time PCR, and laser microdissection before and after the initiation of mastication (newborn, 7 days, 21 days, initiation of mastication, and 35 days). Insulin-like growth factor-1 (IGF-I), transforming-growth-factor-beta-2 (TGFbeta2), and aggrecan mRNAs were clearly expressed at 21 days, while the expression of osteopontin mRNAs was most clear at 35 days. Parathyroid-hormone-related protein (PTHrP), Indian-hedgehog (Ihh), and insulin-like growth factor-2 (IGF-2) mRNAs were clearly expressed during lactation (newborn and 7 days). Heat-shock-protein 84 (HSP-84) and heat-shock-protein 86 (HSP-86) were clearly expressed at 35 days. These results revealed that gene expression changed during mandibular condylar cartilage growth, and that, interestingly, these changes coincided with the initiation of mastication.

Aggrecans↗

Isolation of peptides useful for differential diagnosis of Crohn's disease and ulcerative colitis.

BACKGROUND: Phage displayed random peptide technology has been utilised to identify binding epitopes of antibodies or receptor ligands. AIM: To isolates peptides from a phage library which are specifically recognised by antibodies in serum from patients with Crohn's disease (CD). METHODS: A phage displayed random peptide library composed of nine amino acids was established and sequentially screened using serum immunogloblin G obtained from CD patients. RESULTS: Five different CD specific peptides were isolated from the phage library. No homology in amino acid sequences was observed among four (CDP-1, -3 to -5) of the five peptides exhibiting different binding characteristics with each CD patient's serum. In contrast, two peptides (CDP-1 and -2) had similar amino acid sequences and similar binding characteristics. Four multiple antigenic peptides (MAP, CDP-1, -3 to -5) were synthesised, and an enzyme linked immunosorbent assay (ELISA) using the four peptides was developed to detect serum antibodies against them. Fifty two of 92 CD patients (56.5%) were detected by ELISA, none of 20 ulcerative colitis (UC) patients, only one of 25 duodenal ulcer patients, and only three of 48 healthy subjects. CONCLUSIONS: ELISA using the four peptides isolated in this study may be useful for the differential diagnosis of CD and UC.

Amino Acid Sequence↗

Does decreased T1 signal intensity in the retrodiscal tissue of the temporomandibular joint reflect increased density of collagen fibres?

OBJECTIVE: To evaluate whether decreased signal intensity on T(1) weighted MR images of the retrodiscal tissue of the temporomandibular joint (TMJ) reflects increased density of collagen fibres. METHODS: Corrected sagittal T(1) weighted MR images of six TMJs from six fresh cadavers (three males and three females; age range 76-87 years, mean 80.8 years) were obtained. Following MRI, slices of tissue samples were taken from the cadavers that exactly matched the planes of the MR image. These samples were fixed, decalcified and stained (haematoxylin-eosin stain, Elastica van Gieson's stain) for light microscopy. The samples were evaluated for density of collagen fibres according to Hall et al (1984) and for vascularity, arterial wall thickness, fat content and elastin. In these sagittal samples, the retrodiscal tissue was divided anteroposteriorly and vertically into six areas and each area was classified by histological parameters. The MR images were similarly divided into six areas. Areas with reduced signal intensity were classified as the low signal group and those with no reduced signals were classified as the control group. RESULTS: Collagen density assessed histologically differed between the low signal intensity group and the control group, and loose collage density on the histological samples was observed significantly more often in the low signal group (Fisher's exact test, P=0.03). There were no statistically significant differences in the other categories between the two groups. CONCLUSION: The results suggest that reduced T1 signals of retrodiscal tissue do not necessarily reflect a dense distribution of collagen fibres.

Aged↗

PKCtheta II, a new isoform of protein kinase C specifically expressed in the seminiferous tubules of mouse testis.

Protein kinase C (PKC) theta, a Ca(2+)-independent isoform of PKC, has been known to be expressed in skeletal muscle and T cells. In the present study, we isolated and characterized a smaller transcript expressed in the mouse testis, the cDNA of which is referred hereafter as PKCthetaII and the original PKCtheta as PKCthetaI. The cDNA clone of PKCthetaII has 2184 base pairs and 464 amino acids in the possible open reading frame, consisting of the 5' unique sequence of 20 amino acids and the PKCthetaI sequence of 444 amino acids. Genomic DNA analysis revealed that transcription of PKCthetaII is initiated from the PKCthetaII-specific exon, which is located between exons 7 and 8 of the PKCtheta gene, indicating that alternative splicing is the mechanism by which PKCthetaII is generated. PKCthetaII is expressed exclusively in the testis in an age-dependent manner with sexual maturation. In situ hybridization and reverse transcription-polymerase chain reaction of microdissected tissues clearly demonstrated that PKCthetaII is expressed in the seminiferous tubules of the mouse testis. Consistent with its molecular structure lacking the C1 regulatory domain, PKCthetaII is constitutively active as determined by an in vitro kinase assay, being independent of PKC activators, e.g. phosphatidylserine and phorbol ester. PKCthetaII may play a crucial role in spermatogenesis or some related function of the testis.

Alternative Splicing↗

Induction of epithelial differentiation and DNA demethylation in hamster malignant oral keratinocyte by ornithine decarboxylase antizyme.

The hamster ornithine decarboxylase antizyme (ODC-Az) cDNA was transfected into the hamster malignant oral keratinocyte cell line, HCPC-1. Ectopic expression of ODC-Az resulted in the reversion of malignant phenotypes and alteration of DNA methylation status of CCGG sites. The phenotypes examined include ODC enzymatic activity, doubling time, morphological change, anchorage dependent growth, tumorigenicity in nude mice, induction of epithelial differentiation marker protein (involucrin), and change of cell cycle position. Comparison of CCGG DNA methylation status of the ODC-Az and control vector transfectants revealed a significant increase in demethylation of 5-methyl cytosines (m5C) of CCGG sites in the ODC-Az transfectants. Ectopic expression of ODC-Az gene in hamster malignant oral keratinocytes led to reduce ODC activity and the subsequent demethylation of 5-methyl cytosines, presumably via the ODC/ polyamines/ decarboxylated S-adenosylmethionine (dc-AdoMet) pathways. Our data suggest that ODC-Az shared the same pathway of polyamines/ dc-AdoMet/DNA methyltransferase (DNA MTase). We propose that ODC-Az mediates a novel mechanism in tumor suppression by DNA demethylation and presumably re-activation of key cellular genes silenced by DNA hypermethylation during cancer development. Oncogene (2001) 20, 24 - 33.

Agar↗

Evaluation of urinary rapid test for Helicobacter pylori in general practice.

There is increasing interest in noninvasive tests for the diagnosis of Helicobacter pylori (H. pylori) infection. One such test, a urine-based rapid test kit (RAPIRUN H. pylori Antibody, Otsuka Pharmaceutical Co., Ltd.) for detection of antibody to H. pylori, has been developed and is considered ideal. In addition to its noninvasiveness and safe handling-due to use of urine as a sample-the assay procedure used for the urinary rapid test is very simple. Only 10-20 minutes are required to complete an assay, and no instruments are needed. The aim of this study was to examine the clinical usefulness of this urine-based rapid test. A total of 189 patients, including 76 patients with gastroduodenal disease, were recruited. A pair of random single-void urine and serum samples was collected from each of the 189 patients, and antibody to H. pylori in the urine and serum samples was measured using the urine-based rapid test kit and three commercially available serum-based ELISA kits. For the patients with gastroduodenal disease, invasive diagnostic methods using endoscopic biopsy specimens such as culture, histology, and rapid urease test were also performed. The sensitivity, specificity, and accuracy of the urinary rapid test were evaluated on the basis of the three serum ELISA results or the invasive diagnostic results. In addition, various urinalyses were performed, and the effects of substances existing in urine on the urinary rapid test results were examined. Of the 189 patients, the urinary rapid test was positive for 110 (58.2%), negative for 78 (41.3%), and invalid for only one patient (0.5%). Based on the three serum-based ELISA results, the sensitivity, specificity, and accuracy of the urinary rapid test were 93.7, 88.9, and 92.2%, respectively. On the basis of the biopsy-based test results, the sensitivity of the urinary rapid test was 100% and its accuracy (95.2%) was equivalent or superior to that of each serum-based ELISA. In addition, no significant differences were observed between groups positive and negative on urinary rapid testing in any urinalysis parameter examined. The novel urinary rapid test kit evaluated in this study enables simple, rapid, and accurate diagnosis of H. pylori infection, and is an ideal test method for point-of-care testing.

Adult↗

On-site diagnosis of H. pylori infection by urine.

We have recently developed an on-site diagnostic kit for H. pylori infection using urine (utilizing immunochromatographic method employing a nitrocellulose membrane coated by extracted H. pylori antigen). Accordingly, we investigated its usefulness in 155 consecutive dyspeptic patients using the 13C urea breath test as a gold standard and further compared its performance with two commercially available rapid diagnostic kits that use whole blood (Helisal Rapid Blood, and ImmunoCard H. pylori). As the results, the urine based on-site diagnostic kit provided 95.9% sensitivity and 87.9% specificity with 92.9% accuracy, which were comparable or even better than that of both rapid whole blood tests, suggesting its usefulness in screening of H. pylori infection.

Antigens, Bacterial↗

Urine-based enzyme-linked immunosorbent assay for the detection of Helicobacter pylori infection in children.

OBJECTIVE: Serology and (13)C-urea breath test have been widely used as noninvasive tests to detect Helicobacter pylori infection. However, easier collection of samples and lower costs are desirable for diagnosis of the individual patient or for use in epidemiologic studies. Our aim was to study the diagnostic accuracy of a recently developed urine-based enzyme-linked immunosorbent assay (ELISA) kit for the detection of H pylori-specific immunoglobulin G (IgG) antibodies in children. STUDY DESIGN: Specimens of serum and randomly voided urine were collected from 816 children (0-15 years old) and were analyzed using 2 serum-based ELISA kits and a urine-based ELISA kit, respectively. Based on results of serology, the sensitivity, specificity, and accuracy of the urine-based ELISA kit were evaluated. With regard to false-positive and false-negative results, urinary IgG concentrations and IgG/creatinine levels were studied. RESULTS: Both serum-based ELISAs were positive in 41 children and were negative in 666, who were enrolled in this study. The remaining 109 children were excluded because of disagreement between the results of the 2 serum-based ELISAs, including indeterminate values. Overall sensitivity, specificity, and accuracy of urine-based ELISA test compared with serology were 85.4%, 95.5%, and 94.9%, respectively. On positivity rates, the urine-based ELISA was closely coincident with the serum-based ELISA in each age group. There was no correlation between antibody levels detected by urine-based ELISA and each serum-based ELISA. Urinary IgG concentrations and IgG/creatinine levels were significantly higher in false-positives and were lower in false-negatives than in true-positives plus true-negatives for serology. Most of those with false-positive results had trace to moderate proteinuria. CONCLUSIONS: The urine-based ELISA is an alternative to serum-based ELISA for diagnosis of H pylori infection in children and should be suitable for large-scale epidemiologic studies concerning the organism. In children with proteinuria, results of the test should be interpreted with caution. It is possible that the urine-based ELISA method would be applicable to diagnosis of other infectious diseases.

Adolescent↗

Participation of periodontal ligament cells with regeneration of alveolar bone.

BACKGROUND: It is important to clarify the participation of periodontal ligament (PDL) cells in the regeneration of alveolar bone to establish a reliable approach for obtaining periodontal regeneration. The aim of this study was to determine whether PDL cells play an important role in alveolar bone repair during the course of periodontal regeneration. METHODS: In an in vitro study, the expression of the osteoblast phenotype, such as alkaline phosphatase activity and parathyroid hormone-dependent 3',5'-cyclic adenosine monophosphate accumulation, was investigated in dog PDL cells (DPLC) and dog bone cells isolated from mandibles (DBC). In a related study, the roots of mandibular third premolars extracted from aged dogs were divided into a PDL(+) group, in which the PDL was preserved, and a PDL(-) group, in which the PDL was removed. These roots were respectively transplanted into surgically created bone cavities with buccal and interproximal bone defects in an edentulous area, prepared in advance by extraction of mandibular fourth premolars. These bone defects with the transplanted roots were completely covered with submerged physical barrier membranes. New bone formation and new connective tissue attachment, which require new cementum and insertion of functionally oriented new collagen fibers of periodontal ligament, were histomorphometrically assessed, and were compared between the PDL(+) and PDL(-) groups 6 weeks after transplantation. RESULTS: Both cultured DPLC and DBC exhibited the osteoblast phenotype. New connective tissue attachment was observed only in the PDL(+) group. However, alveolar bone was almost completely regenerated to the original bone height in both the PDL(+) and PDL(-) groups, and the amount of newly formed bone was not significantly different between the 2 groups. CONCLUSIONS: DPLC retain the capability to differentiate into an osteoblast lineage and may act in the regeneration of periodontal ligament with new cementum formation, whereas these cells may have a limited influence on alveolar bone formation during the course of periodontal regeneration.

Alkaline Phosphatase↗

[Clinical study on prognostic factors in thyroid carcinoma].

We treated 227 patients, 45 men and 182 women, with thyroid carcinoma at our hospital from 1984 to 1998. Of these, 177 had papillary carcinoma and 50 follicular carcinoma. The extent of resection was based on tumor size in papillary carcinoma but not follicular carcinoma, and 70% of carcinoma patients underwent hemithyroidectomy. Neck lymph nodes were resected in 93.2% of papillary carcinoma patients, with D1 neck dissection in 45.7% and D2 or D3 neck dissection in 47.5%. In contrast, 70% of follicular carcinoma patients with lymph node resection had D1 dissection. Locoregional recurrence was noted in 22 patients and distant metastasis in 6 cases. Nonsurvivors numbered 17, 12 papillary and 5 follicular carcinoma patients, died of their primary disease. Almost all deaths were in patients with advanced disease, pT3 in 3, pT4 in 10, N1a in 3 and N1b in 8. The prognostic factors for papillary carcinoma were extracapsular spread, age, and distant metastasis, while the only factor for follicular carcinoma was distant metastasis. The 5-year survival for patients with papillary carcinoma was 93.0% and 10-year survival 88.8%, compared to 5-year survival for 93.5% of follicular carcinoma patients and 10-year survival for 93.5%.

Adolescent↗

Histopathological and physiological characteristics of cultured human ACTH-secreting cells derived from a rapidly growing pituitary adenoma.

We observed the histopathological and physiological characteristics of adrenocorticotropic hormone (ACTH)-secreting adenoma cells derived from a rapidly growing pituitary adenoma, which have firm cell attachment and well-preserved hormonal function in a relatively longterm culture. Corticotrophs, obtained from a 43-year-old woman with Cushing's disease in whom plasma ACTH levels increased in response to 1-deamino-8-D-arginine vasopressin (DDAVP) stimulation and the proliferative potential was very high, were grown in tissue culture for up to 6 months. The morphological features were observed by phase contrast and electron microscopy. The cultured cells were incubated with corticotroph-releasing hormone (CRH), arginine vasopressin (AVP), or DDAVP, and ACTH in the medium was measured by radioimmunoassay (RIA). The morphology of the ACTH-secreting adenoma cells in culture revealed a mixed population of formed clusters and spindle-shaped fibroblast-like cells. The adenoma cells were immunohistochemically positive only for ACTH. On electron microscopic observation, pituitary tumor cells obtained 6 days after seeding demonstrated many secretory granules, well-developed rough endoplasmic reticulum, and mitochondria; fewer secretory granules were observed after cultivation for 24 days. ACTH levels in the incubation media were elevated with stimulation by DDAVP, AVP, or CRH. In this study, the establishment of relatively longterm culture of human pituitary adenoma cells seemed to be due to the high proliferative potential of this adenoma. This in vitro study may imply that DDAVP as well as AVP directly stimulates ACTH release from corticotropic adenoma cells.

Adenoma↗

Clinical usefulness of urine-based enzyme-linked immunosorbent assay for detection of antibody to Helicobacter pylori: a collaborative study in nine medical institutions in Japan.

BACKGROUND: A urine-based enzyme-linked immunosorbent assay (ELISA) kit for detection of antibody to Helicobacter pylori has been developed in Japan. Urine samples can be obtained noninvasively and are easier and safer to handle than are serum samples. The aim of this study was to examine the clinical usefulness of this urine-based ELISA kit. MATERIALS AND METHODS: A pair of random, single-void urine and serum samples was collected from each of 1,061 subjects, including 238 patients with gastroduodenal disease. The sensitivity and specificity of the urine-based ELISA was compared with those of three commercially available serum-based ELISA kits. For those patients with gastroduodenal disease, the urine- and serum-based ELISA results were also compared with those for other diagnostic methods using endoscopic biopsy specimens, such as culture, histology, and rapid urease tests. RESULTS: Based on the three serum-based ELISA results, the sensitivity, specificity, and accuracy of the urine-based ELISA were 97.7%, 95.6%, and 96.8%, respectively. On the basis of the biopsy test results, the sensitivity (96.2%), specificity (78.9%), and accuracy (91.0%) of the urine-based ELISA were almost equivalent or superior to all three serum-based ELISAs tested. In addition, 10 of the 12 false-positive cases for urine-based ELISA were confirmed to be true positives for antibodies to H. pylori by Western blot analysis and inhibition ELISA. CONCLUSIONS: The urine-based ELISA (URINELISA H. pylori Antibody) is very accurate and should be useful as an alternative to serum-based ELISAs for screening of H. pylori infection.

Antibodies, Bacterial↗

A new rapid test for detecting anti-Helicobacter pylori antibody excreted into urine.

BACKGROUND: Helicobacter pylori infection has been one of the most common infectious diseases in the world, whereas a gold standard for identifying its infection has not yet been established. The specific test will depend on the particular clinical, epidemiological, and scientific requirements. We recently developed a new type of rapid test to detect H. pylori antibody excreted into urine; the test requires only 20 minutes. The purpose of this study was to examine the accuracy of this rapid test. METHODS: The performance of the rapid test was compared with those of a histological search through Giemsa staining and of an assay for detecting antibodies in serum by a commercially available ELISA kit. The patients, totaling 117 (male, 62, female, 55; average age, 51.6 years), included those with peptic ulcer endoscopically diagnosed and excluded cases that were subjected to eradication therapy in the past. RESULTS: With respect to the determinations of H. pylori identified by the microscopical test and the serum antibody assay, our kit had a sensitivity of 92. 0% and a specificity of 93.1%, and the agreement of determination of H. pylori infection was as high as 91.5% and 92.3%, respectively. CONCLUSIONS: The rapid test for antibodies to H. pylori in urine could detect H. pylori infection easily, rapidly, and noninvasively and would be useful in general practice for screening patients with dyspeptic symptoms.

Antibodies, Bacterial↗