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Biomedical subjects

T Shimoyama

Publications and source records attributed to T Shimoyama.

At least 19 recordsLinked to original sources
PubMed2006

Akt-dependent nuclear localization of Y-box-binding protein 1 in acquisition of malignant characteristics by human ovarian cancer cells.

Y-box-binding protein 1 (YB-1), which is a member of the DNA-binding protein family containing a cold-shock domain, has pleiotropic functions in response to various environmental stimuli. As we previously showed that YB-1 is a global marker of multidrug resistance in ovarian cancer and other tumor types. To identify YB-1-regulated genes in ovarian cancers, we investigated the expression profile of YB-1 small-interfering RNA (siRNA)-transfected ovarian cancer cells using a high-density oligonucleotide array. YB-1 knockdown by siRNA upregulated 344 genes, including MDR1, thymidylate synthetase, S100 calcium binding protein and cyclin B, and downregulated 534 genes, including CXCR4, N-myc downstream regulated gene 1, E-cadherin and phospholipase C. Exogenous serum addition stimulated YB-1 translocation from the cytoplasm to the nucleus, and treatment with Akt inhibitors as well as Akt siRNA and integrin-linked kinase (ILK) siRNA specifically blocked YB-1 nuclear localization. Inhibition of Akt activation downregulated CXCR4 and upregulated MDR1 (ABCB1) gene expression. Administration of Akt inhibitor resulted in decrease in nuclear YB-1-positive cancer cells in a xenograft animal model. Akt activation thus regulates the nuclear translocation of YB-1, affecting the expression of drug-resistance genes and other genes associated with the malignant characteristics in ovarian cancer cells. Therefore, the Akt pathway could be a novel target of disrupting the nuclear translocation of YB-1 that has important implications for further development of therapeutic strategy against ovarian cancers.

Animals↗
PubMed2006

Pacinian neuroma in adipose herniation of the buccal mucosa.

An interesting case of a trauma-induced tender mass of the buccal mucosa in a 45-year-old man was presented. Following surgery, the patient was relieved from pain. Microscopically, the mature adipose tissue is unique in that it contained a single enlarged Pacinian corpuscle near the deep margin. This is the hitherto undescribed intraoral lesion of Pacinian neuroma in the herniated buccal fat pad.

Adipose Tissue↗
PubMed2006

Reference profiling of the genomic response induced by an antimicrotubule agent, TZT-1027 (Soblidotin), in vitro.

TZT-1027 is an antimicrotubule agent targeting beta-tubulin that is undergoing clinical development. The genomic response of cancer cells to TZT-1027 was profiled to evaluate its biochemical activity. A lung cancer cell line, PC-14, was exposed to antimicrotubule agents including dolastatins, Vinca alkaloids and taxanes at an equivalent toxicity level. Alterations in the TZT-1027-induced gene expression of approximately 600 genes were then examined using microarray technology and the resulting gene profiles were compared with those for cells exposed to the other antimicrotubule agents. A principle component analysis using the whole gene set demonstrated that TZT-1027 produced similar gene profiles to those produced by dolastatin 10, but that these gene profiles differed from those produced by other agents. The agents were classified according to their induced genomic response in a molecular structure-dependent manner. Genes whose expression profiles differed according to drug class included intermediate filaments, extracellular matrix protein and Rho regulatory genes that may be involved in cytoskeletal and angiogenesis processes that are regulated by microtubule dynamics. TZT-1027 produces a unique genomic response profile distinct from that of Vinca alkaloids and taxanes, suggesting that this agent has a different mechanism of action. The selected genes may act as pharmacodynamic biomarkers allowing the unique mode of action of TZT-1027 to be discriminated from those of other antimicrotubule agents.

Antineoplastic Agents↗
PubMed2006

Abnormal pontine activation in pathological laughing as shown by functional magnetic resonance imaging.

To explore the aetiology of pathological laughing, a 65-year-old woman with pathological laughing was examined by 3-T functional magnetic resonance imaging (fMRI) before and after treatment with drugs. Here, we report that the patient consistently showed exaggerated pontine activation during the performance of three tasks before treatment, whereas abnormal pontine activation was no longer found after successful treatment with the selective serotonin reuptake inhibitor, paroxetine. Our findings in this first fMRI study of pathological laughing suggest that serotonergic replacement decreases the aberrant activity in a circuit that involves the pons.

Affective Symptoms↗
PubMed2005

Peripheral odontogenic tumor: a clinicopathologic study of 30 cases. General features and hamartomatous lesions.

BACKGROUND: Peripheral odontogenic tumors (POT), either neoplastic or hamartomatous, are rare. This study briefly summarizes the general features of POT and selectively reviews the histomorphologic spectrum of under-recognized hamartomatous lesions that we have designated peripheral odontogenic hamartomas (POH) in order to shed more light into the pathogenesis of POT. METHODS: Archival material accessioned at our institutions between 1970 and 2004 was systematically searched to identify examples of POT/POH. RESULTS: Among 39 660 biopsies, we retrieved 25 cases of 'classical' POT and five cases of 'unique' POH. Odontogenic fibroma and ameloblastoma were by far the most common. Of POH, two purely epithelial lesions showed multiple strands of basaloid rests [odontogenic gingival epithelial hamartoma (OGEH)] and a conglomerate of polyhedral epithelium, ghost cells and concentric calcifications (calcifying epithelial odontogenic tumor-like hamartoma), respectively. OGEH and peripheral squamous odontogenic tumor (PSOT) deserve to be a related entity. In two types of mixed POH, ectomesenchymal elements appeared juxtaposed to the squamous lining (gingival cyst-like organoid hamartoma) and ghost cells aggregated in the enamel organ of a microdont (peripheral odontoma). None of POH exhibited continuity with the surface epithelium. CONCLUSION: On the basis of this relatively limited series of cases, POH, to conceptualize a unified histogenetic source, are speculated to arise from the soft-tissue remnants of dental lamina. Gingival rests of Serres seem to retain the ability to pursue epithelial-ectomesenchymal interactions that are necessary leading to odontoma formation.

Ameloblastoma↗
PubMed2005

Collagenous fibroma (desmoplastic fibroblastoma): a new case originating in the palate.

A 49-year-old woman presented with a painless slowly growing but huge polypoid palatal mass. On magnetic resonance imaging (MRI), areas of low signal intensity were consistent with a fibrous tumour. T(1) and T(2) weighted MRI after Gd-DTPA administration highlighted a well-circumscribed, purely soft tissue process. Histological analysis of the operative specimen detected collagenous fibroma (desmoplastic fibroblastoma). The patient remains disease-free 4 years after excision.

Collagen↗
PubMed2005

A vacuum-formed splint for luxated tooth with a repositioning on the model.

The results of fixation of a luxated tooth using a vacuum-formed splint, formed on a plaster model after repositioning of the luxated tooth on the model are presented. This may be useful where the adjacent tooth gap is wide or only minimal anchorage and support are available from the adjacent teeth.

Child↗
PubMed2004

Effect of incorporating low intensity exercise into the recovery period after a rugby match.

BACKGROUND: The psychological and physiological condition of athletes affect both their performance in competitions and their health. Rugby is an intense sport which appears to impose psychological and physiological stress on players. However, there have been few studies of the most appropriate resting techniques to deliver effective recovery from a match. OBJECTIVES: To compare the difference in recovery after a match using resting techniques with or without exercise. METHODS: Fifteen Japanese college rugby football players were studied. Seven performed only normal daily activities and eight performed additional low intensity exercise during the post-match rest period. Players were examined just before and immediately after the match and one and two days after the match. Blood biochemistry and two neutrophil functions, phagocytic activity and oxidative burst, were measured to assess physiological condition, and the profile of mood states (POMS) scores were examined to evaluate psychological condition. RESULTS: Immediately after the match, muscle damage, decreases in neutrophil functions, and mental fatigue were observed in both groups. Muscle damage and neutrophil functions recovered with time almost equally in the two groups, but the POMS scores were significantly decreased only in subjects in the low intensity exercise group. CONCLUSIONS: Rugby matches impose both physiological and psychological stress on players. The addition of low intensity exercise to the rest period did not adversely affect physiological recovery and had a significantly beneficial effect on psychological recovery by enhancing relaxation.

Activities of Daily Living↗
PubMed2004

Adverse effects of energy restriction on changes in immunoglobulins and complements during weight reduction in judoists.

AIM: A preliminary study to investigate the combined effects of dietary restriction and weight reduction through exercise on markers of immune function in college judoists before and after a single competition. METHODS: Forty-nine judoists participated in the study. Thirty-eight athletes combined exercise and dietary restriction (WR group), and 11 athletes did not require dietary restriction (EX group). Changes in anthropometric parameters, energy intake, concentrations of serum immunoglobulins and complements, and white blood cell counts were assessed at 4 time points: 20 days (pre-values), 4 days and 1 day before the competition, and 7 days after the competition. RESULTS: Compared with pre-values, the WR group exhibited significant decreases in body weight (-2.8 kg at 1 day before) and fat free mass (-1.7 kg at 1 day before); there were no changes in these variables in the EX group. The WR group exhibited significant decreases in IgG, IgM and C3 at 7 days after the competition (all p<0.01). In the EX group, significant decreases in IgM and C3 (both p<0.05) were observed at 7 days after the competition, though to a lesser degree than in the WR group. CONCLUSIONS: Energy restriction seemed to exacerbate alterations in immune markers such as immunoglobulin and complement induced by vigorous exercise at 7 days after a competition. Although the changed values were still within normal limits, we hypothesize that the potential cumulative effect of these changes over many competitions in 1 year might well induce abnormal levels with a possibly harmful clinical effect on judoists.

Adult↗
PubMed2003

Neural substrates participating in acquisition of facial familiarity: an fMRI study.

The amygdala is related to recognition of faces and emotions, and functional magnetic resonance imaging (fMRI) studies have reported that the amygdala is habituated over time with repetition of facial stimuli. When subjects are presented repeatedly with unfamiliar faces, they come to gradually recognize the unfamiliar faces as familiar. To investigate the brain areas participating in the acquisition of familiarity to repeatedly presented unfamiliar faces, we conducted an fMRI study in 16 healthy subjects. During the task periods, the subjects were instructed to see presented unfamiliar faces repeatedly and to judge whether the face was male or female or whether the face had emotional valences. The experiment consisted of nine sessions. To clarify the brain areas that showed increasing or decreasing activation as the experimental session proceeded, we analyzed the fMRI data using specified linear covariates in the face recognition task from the first session to the ninth session. Imaging data were investigated on a voxel-by-voxel basis for single-group analysis according to the random effect model using Statistical Parametric Mapping. The bilateral posterior cingulate cortices showed significant increases in activity as the experimental sessions proceeded, while the activation in the right amygdala and the left medial fusiform gyrus decreased. Thus, the posterior cingulate cortex may play an important role in the acquisition of facial familiarity.

Adult↗
PubMed2003

Subpontic cartilagenous hyperplasia of the mandible.

We report here a case of subpontic cartilagenous hyperplasia of the lower first molar of a 65-year-old woman. A sessile mass of calcifying hyaline cartilage firmly attached to the alveolar ridge was found below the pontic of a fixed partial denture. This is a novel type of reactive cartilagenous metaplasia in the subpontic tissue.

Aged↗
PubMed2003

Effects of rebamipide, a gastro-protective drug on the Helicobacter pylori status and inflammation in the gastric mucosa of patients with gastric ulcer: a randomized double-blind placebo-controlled multicentre trial.

AIMS: To investigate the effects of rebamipide on the Helicobacter pylori eradication rate with amoxicillin and omeprazole. The trial also examined its histological effects on gastro-mucosal inflammation after eradication. METHODS: Two hundred and six H. pylori-positive patients with active gastric ulcer underwent 8-week based therapy (OA) consisting of 2-week amoxicillin with omeprazole and subsequent 6-week omeprazole. They randomly received either rebamipide (OA-R) or placebo (OA-P) for 16 weeks: combined with the OA based therapy, and subsequently for another 8 weeks. Besides eradication rate, inflammatory findings of gastric mucosa after eradication were evaluated histologically. RESULTS: Per Protocol Set analysis showed no significant difference in eradication rate between OA-R (64.6%; 95% confidence interval, 54.3-75.0%) and OA-P (67.9%; 95% CI, 57.6-78.3%). Histological findings in the gastric mucosa of the ulcer region, however, indicated a significant improvement (P = 0.017) in inflammation scores in OA-R (1.84 +/- 0.41) compared with that in OA-P (2.02 +/- 0.39) after 16-weeks of treatment. This suppressive effect on inflammation was observed even in the OA-R patients unsuccessfully eradicated. CONCLUSION: Rebamipide demonstrated a suppressive effect on the persistent and possibly chronic inflammation in the gastric mucosa of the ulcer region after eradication, but the drug did not improve the eradication rate.

Adult↗
PubMed2003

Development of predictive equations for body density of sumo wrestlers using B-mode ultrasound for the determination of subcutaneous fat thickness.

OBJECTIVE: To develop an equation for predicting the body density of sumo wrestlers. METHODS: The following were measured: subcutaneous fat thickness measured at nine sites using B-mode ultrasound equipment; circumference at seven sites; hand to leg bioelectrical impedance. The subjects consisted of 24 college sumo wrestlers (mean age 19.7 years, mean body weight 111.2 kg) and 24 matched obese controls (mean age 19.1 years and mean body weight 111.2 kg). In addition, body density was measured by the underwater weighing method, and the percentage of fat was calculated from the measured body density. RESULTS: Linear regression analysis was used to estimate the relation between body density and other variables, and a predictive equation for the body density was derived: y = 1.088-0.00036 x (fat thickness at nine sites) (r(2) = 0.90) for the sumo wrestler group and y = 1.083-0.00033 x (fat thickness at nine sites) (r(2) = 0.91) for the control group. A multiple regression analysis was performed using the body density as the objective variable, and other measured items as the explanatory variables. This was used to derive a predictive equation: y = 1.121-0.00038 x (fat thickness of abdomen)-0.00043 x (circumference of hips)-0.00142 x (fat thickness of triceps) (r(2) = 0.94) for the sumo wrestler group, and y = 1.076-0.00070 x (fat thickness of abdomen)-0.00140 x (fat thickness of tibialis) (r(2) = 0.91) for the control group. The difference between the two equations was due to the difference in body fat distribution. Neither of these predictive equations is applicable to non-overweight non-athletes. CONCLUSION: This is the first predictive equation developed for the body density of sumo wrestlers.

Adipose Tissue↗
PubMed2003

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↗
PubMed2003

Helicobacter pylori water soluble surface proteins prime human neutrophils for enhanced production of reactive oxygen species and stimulate chemokine production.

BACKGROUNDS/AIMS: Chronic gastritis induced by Helicobacter pylori is characterised by considerable neutrophil infiltration into the gastric mucosa without mucosal invasion of bacteria. Bacteria have different characteristics with respect to their ability to stimulate human neutrophils to produce reactive oxygen species and chemokines. The aim of this study was to examine the effects of H pylori water extracts on the oxidative burst and chemokine production of human neutrophils. METHODS: Helicobacter pylori cells were extracted by harvesting into distilled water and centrifugation. Neutrophils were incubated with H pylori water extracts and the production of reactive oxygen species was measured using luminol dependent chemiluminescence (LmCL). In addition, the concentrations of chemokines (interleukin 8 (IL-8), macrophage inflammatory protein 1-alpha (MIP1-alpha), and MIP1-beta) were measured by enzyme linked immunosorbent assay. Neutrophils were also stimulated by opsonised zymosan (OZ) after preincubation with H pylori water extracts. RESULTS: Helicobacter pylori water extracts alone induced only a weak oxidative burst but preincubation of neutrophils with water extracts dose dependently enhanced the LmCL response stimulated by OZ. Helicobacter pylori water extracts also stimulated neutrophil IL-8 production, although MIP-1beta production was only stimulated weakly, and MIP-1alpha was not stimulated at all. CONCLUSIONS: Helicobacter pylori products in water extracts may have a role in the activation and migration of neutrophils, which results in enhanced oxidative damage to gastric mucosa. These findings may explain the pathology of H pylori induced gastritis, in which there is little invasion of bacteria into the gastric mucosa.

Bacterial Outer Membrane Proteins↗
PubMed2003

Intestinal goblet cell autoantibody associated enteropathy.

This report describes a case of refractory enteropathy with circulating intestinal goblet cell autoantibodies (IGA). A 19 year old man with hyperthyroidism had suffered from protracted diarrhoea for nearly 10 years. Histological examination showed evidence of collagenous enterocolitis. The diarrhoea did not improve despite fasting under total parenteral nutrition. An immunofluorescence assay demonstrated IGA without anti-enterocyte autoantibodies, the hallmark of autoimmune enteropathy, although other criteria were fulfilled. None of 109 controls, including 55 cases of inflammatory bowel disease and one of lymphocytic colitis, had IGA. This case is considered to be a variant of autoimmune enteropathy, and might be a distinct entity.

Adult↗
PubMed2003

Tourette's syndrome with rapid deterioration by self-mutilation of the upper lip.

A case of Tourette's syndrome is presented in a thirteen-year-old boy with obsessive-compulsive symptoms including self-mutilation of the upper lip. His upper lip injury was caused by complication of picking with fingernail, and self-biting with the lower anterior teeth. It became rapidly worse and the median part of the upper lip collapsed. But the placement of an acrylic splint was able to prevent further damage of the upper lip.

Adolescent↗