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T Ito

Publications and source records attributed to T Ito.

At least 19 recordsLinked to original sources
PubMed2006

Anthropogenic radionuclides in sediment in the Japan Sea: distribution and transport processes of particulate radionuclides.

Distributions of anthropogenic radionuclides ((90)Sr, (137)Cs and (239+240)Pu) in seabed sediment in the Japan Sea were collected during the period 1998-2002. Concentration of (90)Sr, (137)Cs and (239+240)Pu in seabed sediment was 0.07-1.6 Bq kg(-1), 0.4-9.1 Bq kg(-1) and 0.002-1.9 Bq kg(-1), respectively. In the northern basin of the sea (Japan Basin), (239+240)Pu/(137)Cs ratios in seabed sediment were higher and their variation was smaller compared to that in the southeastern regions of the sea. The higher (239+240)Pu/(137)Cs ratios throughout the Japan Basin were considered to reflect production of Pu-enriched particles in the surface layer and substantial sinking of particulate materials in this region. In the southern regions of the Japan Sea (<38 degrees N), both inventories and (239+240)Pu/(137)Cs ratios in sediment were larger than those in the other regions. In the southern Japan Sea, observations suggested that supply of particulate radionuclides by the Tsushima Warm Current mainly enhanced accumulation of the radionuclides in this region.

Cesium Radioisotopes↗
PubMed2006

Intracranial angiosarcoma arising from a schwannoma.

Angiosarcomas rarely arise from schwannomas, but we describe here a case of angiosarcoma that arose from a remnant of a benign vestibular schwannoma that had been removed 10 years earlier. The patient was a 66-year-old man with no sign of neurofibromatosis. Although we attempted surgical resection, we could not totally remove the tumour. The patient died nine months after diagnosis, primarily as result of an abscess in the cerebellum and base of the skull. The histological diagnosis was confirmed by the immunohistochemical findings of positivity for CD34 antigen and S-100 protein in the resected tumour.A review of the literature revealed four other cases of angiosarcoma with schwannoma, all of which arose from an extracranial nerve. The present case is the first report of an angiosarcoma with schwannoma arising from an intracranial locus.

Aged↗
PubMed2006

Effects of electrical stimulation of the raphe area on the micturition reflex in cats.

The raphe nucleus has a variety of physiological functions, including emotion, regulation of skeletal muscle motoneurons, spinal transmission of nociceptive signals, sleep, respiration, gastric motility, and cardiovascular function. Recent evidence has shown that centrally administered serotonin has modulatory effects on micturition function, and that decreased brain serotonin might underlie depression and an overactive bladder. We applied high-frequency stimulation (HFS; 0.2-ms duration, 100 Hz) in the raphe nucleus and the adjacent midline area in 20 supracollicular decerebrate cats, which mostly elicited inhibition of the micturition reflex. The effective amplitude of the electrical stimulation for evoking inhibitory responses was less than 50 muA. We also examined single neuronal activities in the raphe nucleus in response to isovolumetric spontaneous micturition reflexes. In total, 79 neurons were recorded in the raphe nucleus that were related to urinary storage/micturition cycles. Of the neurons recorded, the most common were tonic storage neurons (48%), followed by tonic micturition neurons (28%), phasic storage neurons (18%), and phasic micturition neurons (6%). In addition to the tonic/phasic as well as storage/micturition classification, the neurons showed diverse discharge patterns: augmenting, constant and decrementing, with the constant discharge pattern being most common. Among neurons in the raphe nucleus, the neurons with a decrementing discharge pattern were concentrated in the rostral portion, whereas the augmenting and constant neurons existed diffusely. The storage and micturition neurons were intermingled in the rostral portion, whereas they were separate in the caudal portion. In conclusion, the results of the present study indicate that HFS of the raphe area inhibits the micturition reflex and that there are micturition-related neuronal firings in the raphe area in cats, suggesting that the raphe nucleus is involved in neural control of micturition.

Action Potentials↗
PubMed2006

Significance of nerve growth factor overexpression and its autocrine loop in oesophageal squamous cell carcinoma.

Nerve growth factor (NGF) is overexpressed not only in nervous system, but also in several types of cancers. However, the role of NGF in oesophageal squamous cell carcinoma (OESCC) remains unclear. Here, we show the first evidence of NGF-TrkA autocrine loop and clinical significance of NGF overexpression in OESCC. Immunohistochemical study of 109 OESCC specimens revealed that NGF overexpression, found in 63 out of 109 patients (57.8%), was associated with lymph node metastasis, distant metastasis, higher TNM stage, poorer tumour differentiation, and poorer survival. NGF overexpression was also associated with strong expression of TrkA and negative expression of low-affinity neurotrophin receptor (p75NTR). Semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) of 19 surgical specimens showed upregulation of NGF mRNA in 17 out of 19 (89%) patients. All five OESCC cell lines tested in vitro secreted detectable NGF in enzyme-linked immunosorbent assay, and expressed TrkA and p75NTR on RT-PCR and Western blot. The motility of HSA/c, one of the OESCC cell lines overexpressing NGF, was significantly decreased by either neutralising anti-NGF antibody, an inhibitor of TrkA, or NGF-small interfering RNA in transwell migration assay. Our findings suggest that NGF is of potential interest not only as a prognostic factor, but also as a novel therapeutic target in OESCC.

Adult↗
PubMed2006

Transcription factor Ets-1 is essential for mesangial matrix remodeling.

Most advanced glomerular diseases are characterized by abnormal extracellular matrix (ECM) accumulation in the glomeruli, and matrix metalloproteinases (MMPs) play a pivotal role in ECM remodeling in various glomerular diseases. The proto-oncogene, ets-1, is a transcription factor regulating the expression of various matrix proteinases, including MMP-1, MMP-3, and MMP-9. The goal of the present study was to characterize the role of Ets-1 in the progression of glomerular diseases. Overexpression of Ets-1 in cultured mesangial cells prevented transforming growth factor (TGF)-beta-induced inhibition of DNA-binding activity and TGF-beta-induced type I collagen production. In addition, exogenous Ets-1 abolished TGF-beta-induced collagen gel contraction. The in vivo transfection of the ets-1 gene into nephritic kidney resulted in the increases in glomerular MMP-1, MMP-3, and MMP-9 mRNA, decreases in mesangial ECM deposition, and attenuation of fibronectin extradomain A (EDA) and type I collagen expression. In contrast, knockdown of Ets-1 in glomeruli resulted in severe ECM deposition in diseased glomeruli. In conclusion, Ets-1 promotes degradation of ECM proteins and is critical for integral glomerular reorganization.

Animals↗
PubMed2006

Transcriptional profiling suggests that Barrett's metaplasia is an early intermediate stage in esophageal adenocarcinogenesis.

To investigate the relationship between Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC), we determined gene expression profiles of discrete pathological stages of esophageal neoplasia using a sequence-verified human cDNA microarray. Fifty one RNAs, comprising 24 normal esophagi (NE), 18 BEs, and nine EACs were hybridized to cDNA microarrays. Five statistical analyses were used for the data analysis. Genes showing significantly different expression levels among the three sample groups were identified. Genes were grouped into functional categories based on the Gene Ontology Consortium. Surprisingly, the expression pattern of BE was significantly more similar to EAC than to NE, notwithstanding the known histopathologic differences between BE and EAC. The pattern of NE was clearly distinct from that of EAC. Thirty-six genes were the most differentially modulated, according to these microarray data, in BE-associated neoplastic progression. Twelve genes were significantly differentially expressed in cancer-associated BE's plus EAC (as a single combined tissue group) vs noncancer-associated BE's. These genes represent potential biomarkers to diagnose EAC at its early stages. Our results demonstrate that molecular events at the transcriptional level in BE are remarkably similar to BE's-associated adenocarcinoma of the esophagus. This finding alarmingly implies that BE is biologically closer to cancer than to normal esophagus, and that the cancer risk of BE is perhaps higher than we had imagined. These findings suggest that changes modulated at the molecular biologic level supervene earlier than histologic changes, and that BE is an early intermediate stage in the process of EAC.

Adenocarcinoma↗
PubMed2006

Carbon dioxide insufflation attenuates parietal blood flow obstruction in distended colon: potential advantages of carbon dioxide insufflated colonoscopy.

BACKGROUND: Bowel distention after colonoscopy has been considered as a cause of blood flow disturbance. Carbon dioxide (CO2), with its higher absorbability and vasodilating effect, may reduce parietal blood flow disturbance of distended colon when used for intraluminal insufflation instead of air. The purpose of this study was to assess parietal blood flow of the colon distended with intraluminal air/CO2 insufflation. METHODS: A 5-cm segment of rat colon was insufflated with either air (air group) or CO2 (CO2 group). Two insufflation methods were employed: temporary insufflation up to an intraluminal pressure of 60 mmHg and continuous insufflation at a pressure of 5, 15, and 30 mmHg. Bowel distention and parietal blood flow measured by laser Doppler imaging were evaluated. RESULTS: For temporary insufflation, bowel distention was prolonged in the air group, whereas it rapidly resolved in the CO2 group. Parietal blood flow decreased in both groups; however, it recovered within 5 min in the CO2 group. For continuous insufflation, under 5 mmHg insufflation, blood flow decreased in the air group, whereas it increased in the CO2 group. Blood flow decreased in both groups under 15 mmHg insufflation; however, it decreased less in the CO2 group. There was a reverse relationship between insufflation pressure and blood flow difference. Inhibition of nitric oxide synthase, ATP-sensitive K+ channel, or heme oxygenase was ineffective against a CO2-induced increase in blood flow. CONCLUSION: CO2 insufflation preserved parietal blood flow not only by rapid resolution of bowel distention but also by its potential vasodilative effect.

Air↗
PubMed2006

Adenoviral-mediated overexpression of membrane-bound human FasL and human decoy Fas protect pig islets against human CD8+ CTL-mediated cytotoxicity.

Pig islets are considered to be most suitable source of islets for xenotransplantation into patients with type 1 diabetes mellitus. However, cellular rejection, especially CD8+ CTL-mediated cytotoxicity, remains a formidable barrier preventing long-term xenograft survival. Our previous study demonstrated that human CD8+ CTLs were highly detrimental to xenograft cells and that this strong cytotoxicity of human CTLs was mediated mainly by the Fas/FasL apoptotic pathway. Furthermore, we exploited novel methods for inhibiting human CD8+ CTL-mediated xenocytotoxicity with overexpression of membrane-bound human FasL and human decoy Fas antigen in xenografted cells. In the present study, we assessed the cytoprotective effects of these novel inhibitory molecules overexpressed by an adenoviral-mediated system in pig islets. Isolated pig islets were transfected with adenovirus vector encoding either human decoy Fas or membrane-bound human FasL genes. Thirty percent to 60% of transfected pig islets expressed these molecules producing 60% to 88% suppression of CTL killing compared with parental pig islets. These data indicated that pig islet grafts isolated from transgenic pigs with either membrane-bound human FasL or human decoy Fas antigen genes may control the innate cellular response to xenografts, and creating a window of opportunity to facilitate xenograft survival.

Adenoviridae↗
PubMed2006

A novel strategy for preventing human CD8+ cytotoxic T lymphocyte-mediated cytotoxicity against pig endothelial cells by overexpression of pig cellular FLICE-like inhibitory protein (c-FLIP) gene.

Human CD8+ cytotoxic T lymphocyte (CTL)-mediated cytotoxicity in xenograft recipients is an important obstacle for successful xenotransplantation of pig organs into humans. In our previous study, we demonstrated that xenocytotoxicity of human CD8+ CTL detrimental to pig endothelial cells (PEC) is mediated mainly by the Fas/FasL apoptotic pathway. Furthermore, we developed new methods to prevent this CTL killing by extracellular remodeling using overexpression of human decoy Fas antigen and membrane-bound human FasL on pig xenograft cells. The cellular FLICE-inhibitory protein (c-FLIP), a caspase-8 inhibitor that lacks the cysteine domain, is a negative regulator of death receptor-mediated apoptosis. c-FLIP proteins exist as long (c-FLIP(L)) and short (c-FLIPs) splice variants, both capable of protecting cells from death receptor-mediated apoptosis. In this report, we have demonstrated that both pig c-FLIPs and pig c-FLIP(L) significantly inhibit human CD8+ CTL-mediated xenocytotoxicity toward stably transfected PEC, although the expression level of pig Fas antigen on cell surface was not changed. These data suggested that intracellular remodeling with overexpression of pig c-FLIP in xenograft cells may decrease the innate cellular responses against xenografts, facilitating long-term xenograft survival.

Animals↗
PubMed2006

Regulation of donor T cells in the tolerant rats to graft-versus-host disease by FTY720 following small bowel transplantation.

AIMS: The potency of immunosuppression is a critical factor in small bowel transplantation (SBTx). FTY720 altered lymphocyte trafficking and prevented the donor T cells from migrating into target organs, resulting in the prolongation of recipient survival in acute graft-versus-host disease (GVHD) of SBTx. However, the effect of FTY720 on donor T cells in the chronic phase of GVHD following SBTx remains unclear. METHODS: Heterotopic SBTx was performed in a WF-to-F1 (WF x ACI) rat combination. Recipients were given FTY720 for 14 days after SBTx. The subpopulations of donor-derived T cells and the cytokine production in the target tissues were evaluated on postoperative day 150. RESULTS: FTY720 treatment significantly prolonged recipient survival over 150 days without any clinical signs of GVHD. The numbers of donor-derived CD4+ and CD8+ T cells in the peripheral blood, mesenteric lymph nodes, and Peyer's patches of recipients were maintained at low levels on postoperative 150, which were almost similar to the levels on postoperative day 14. In the host lamina propria, however, a significant higher number of donor T cells (CD4+, 18.4 +/- 4.3 x 10(4); CD8+, 13.9 +/- 3.6 x 10(4)) were still observed on postoperative day 150. Production of interferon-gamma was significantly reduced in target tissues by FTY720 treatment both in the acute and chronic phase. However, interleukin-4 and interleukin-10 production, which was significantly higher on day 14, returned to the level of naive rats in the chronic phase. CONCLUSIONS: A 14-day treatment of FTY720 induced tolerance in our SBTx model. Down-regulation of both Th1 and Th2 immune response was observed in the chronic phase.

Animals↗
PubMed2006

An increase in the serum amylase level in patients after peroral double-balloon enteroscopy: an association with the development of pancreatitis.

BACKGROUND AND STUDY AIMS: Double-balloon enteroscopy (DBE) is a novel technique that allows the enteroscope to be inserted deep into the small intestine. The procedure has been thought to be safe, but cases of acute pancreatitis after peroral DBE have recently been observed. The aim of this study was to confirm the occurrence of hyperamylasemia after peroral DBE. PATIENTS AND METHODS: Peroral DBE was carried out in 13 patients from July 2005 to February 2006. Blood samples were taken before and 3 h after the procedure, and serum pancreatic amylase levels were measured. The patients were also evaluated for pancreatic-type abdominal pain after the procedure. Hyperamylasemia after peroral DBE was defined as an elevation of the serum pancreatic amylase level to more than the upper normal limit and twice the level before the procedure. Pancreatitis was diagnosed on the basis of both pancreatic-type abdominal pain and hyperamylasemia. RESULTS: Hyperamylasemia after peroral DBE occurred in six patients (46.2 %). One of the six patients with hyperamylasemia had pancreatic-type abdominal pain after the procedure and developed acute pancreatitis. The average procedure time was 105 min (range 65 - 155 min) in the patients with hyperamylasemia, and did not significantly differ from that in the group without hyperamylasemia (99 min). CONCLUSIONS: Hyperamylasemia after peroral DBE occurs frequently and may be associated with development of pancreatitis.

Adolescent↗
PubMed2006

Male New Zealand Black/KN mice: a novel model for autoimmune-induced permanent alopecia?

BACKGROUND: Irreversible, permanent and scarring alopecia is associated with several autoimmune diseases, including all autoimmune connective tissue disorders. The pathogenesis of autoimmune-induced permanent alopecia (APA) is still poorly understood, and instructive, simple mouse models for the study of APA are needed urgently. During the course of our studies in a well-established mouse model for chronic rheumatoid arthritis, the New Zealand Black/KN (NZB/KN) mouse, we noticed that ageing male NZB/KN mice developed spontaneous APA. OBJECTIVES: To study whether alopecia seen in ageing male NZB/KN mice displays key features of human APA and may, thus, be a useful new mouse model for clinically relevant APA research. METHODS: NZB/KN, the F1 hybrid of NZW/N Slc x NZB/KN (W/BKN F1), the F1 hybrid of NZB/KN x NZW/N Slc (BKN/W F1), and the F2 hybrid of W/BKN F1 x W/BKN F1 mice were employed in this study, in order to check which strain carries the highest risk of alopecia development. Besides routine histology, CD3, CD4 and CD8 expression as well as immunoglobulin (Ig) G and IgM deposition in hair follicles were investigated by immunohistology/immunofluorescence. Mast cell distribution/degranulation and Ki-67 (proliferation)/TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling) (apoptosis) positive cells were also analysed. RESULTS: Only F2 male NZB/KN mice were prone to develop alopecia, suggesting that Y chromosome-associated gene(s) are involved in the pathogenesis of APA, which incidence rises with increasing age. The lesional alopecia skin in 12-month-old male NZB/KN mice showed a sharp decline in hair follicle density, thus meeting a key criterion of permanent alopecia. Both macroscopically and histologically, the alopecia seen in these mice resembled in many respects different stages of clinical APA, such as alopecia associated with chronic discoid lupus erythematosus (DLE) in humans. Lesional APA hair follicles in mice displayed intrafollicular and perifollicular mononuclear cell infiltrates, as well as an increased number of activated (degranulated) perifollicular mast cells. In the fully developed lesion, many CD4+ cells were seen in perifollicular locations, including the epithelial stem cell region (bulge), and also contained a few CD8+ T cells. IgM deposits were found in the follicular basement membrane zone (BMZ). Both in the bulge and the hair matrix region of the affected anagen hair follicles, there were signs of massive keratinocyte apoptosis. CONCLUSIONS: Our currently available data suggest that male but not female NZB/KN mice may indeed represent a suitable mouse model for APA, with some similarities to the permanent alopecia seen in human DLE patients, although additional and confirmatory investigations are needed before this mouse strain can be accepted as a murine equivalent of APA in humans.

Aging↗
PubMed2006

Inhibition of donor-derived T cells trafficking into target organs by FTY720 during acute graft-versus-host disease in small bowel transplantation.

In small bowel transplantation (SBTx), graft-versus-host disease (GVHD) is mediated by donor-derived T cells recognizing host major histocompatibility complex (MHC) alloantigens, and represents an important immunological event influencing life in experimental and clinical situations. We evaluated the possibility that a new sphingosine 1-phosphate receptor agonist, FTY720, could diminish GVHD in a rat SBTx model through traffic alteration of donor-derived T cells in target organs. Heterotopic SBTx was performed using a parent (WF)-into-F(1) (WF x ACI) rat combination. Recipient survival, body weight, histopathology, donor-derived T cell subpopulation and cytokine production were compared with untreated controls. FTY720 inhibited lethality and histopathological changes in target organs when administered at 0.5 mg/kg, possibly due to sequestration of donor-derived T cells in the intestinal graft. FTY720 caused a significant reduction in donor T cell numbers in target organs by promoting these cells to home into donor, but not recipient, secondary lymphoid tissues. FTY720 significantly decreased production of interferon (IFN)-gamma in target organs. These findings indicate that FTY720 effectively reduced recirculation of activated donor-derived T cells and recruitment to target organs in GVHD, and was also associated with down-regulated IFN-gamma production. These properties may offer the potential to treat ongoing GVHD in SBTx.

Acute Disease↗
PubMed2006

Lessons from comparative analysis of species-specific imprinted genes.

Genomic imprinting is generally believed to be conserved in all mammals except for egg-laying monotremes, suggesting that it is closely related to placental and fetal growth. As expected, the imprinting status of most imprinted genes is conserved between mouse and human, and some are imprinted even in marsupials. On the other hand, a small number of genes were reported to exhibit species-specific imprinting that is not necessarily accounted for by either the placenta or conflict hypotheses. Since mouse and human represent a single, phylogenetically restricted clade in the mammalian class, a much broader comparison including mammals diverged earlier than rodents is necessary to fully understand the species-specificity and variation in evolution of genomic imprinting. Indeed, comparative analysis of a species-specific imprinted gene Impact using a broader range of mammals led us to propose an alternative dosage control hypothesis for the evolution of genomic imprinting.

Animals↗
PubMed2006

Emergence of community-associated methicillin-resistant Staphylococcus aureus in Singapore: a further six cases.

INTRODUCTION: The clinical features and molecular epidemiology of further cases of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infection in Singapore are described. METHODS: Six cases of CA-MRSA infection that occurred between April and October 2004 are described. The bacterial isolates were tested for the presence of Panton-Valentine leukocidin (PVL) genes and typed via pulsedfield gel electrophoresis, staphylococcal chromosomal cassette mec (SCCmec) and multi-locus sequence typing. The results were compared with that of previously-reported local and international CA-MRSA isolates. RESULTS: There were four cases of cutaneous abscesses and one each of chronic osteomyelitis and endocarditis. CA-MRSA isolates from the last two cases tested negative for PVL genes. Three isolates were identical and related to the Oceanian clone, and one isolate to the predominant Taiwanese clone. The isolate causing osteomyelitis had a novel sequence type. CONCLUSION: CA-MRSA, though uncommon, is being isolated with increasing frequency in Singapore. A predominant clone (ST30- MRSA-IV) seems to be emerging locally.

Adult↗