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Biomedical subjects

T Himi

Publications and source records attributed to T Himi.

At least 19 recordsLinked to original sources

Ossifying fibroma of the mandible with primary hyperparathyroidism due to non-familial parathyroid adenoma.

Ossifying fibroma is an uncommon benign osteogenic neoplasm arising from cells of the periodontal ligament, typically with a slowly progressive enlargement of the affected bone. The neoplasm sometimes presents with hyperparathyroidism, most of which cases are due to familial parathyroid tumours. We report a rare case of ossifying fibroma of the mandible which showed very rapid growth and presented with primary hyperparathyroidism due to non-familial parathyroid adenoma. Despite improvement of parathyroid dysfunction after removal of the parathyroid adenoma, the tumour continued to grow very aggressively. The case required partial mandibular resection for complete resection of the tumour, and fixation of the remaining mandible with a titanium plate.

Adenoma↗

Effect of glucocorticosteroids on tumour necrosis factor-alpha-induced intercellular adhesion molecule-1 expression in cultured primary human nasal epithelial cells.

OBJECTIVE: In order to confirm the direct effect of glucocorticosteroids on epithelial intercellular adhesion molecule-1 (ICAM-1) expression, we examined ICAM-1 expression on primary cultured human nasal epithelial cells (HNECs) at both protein and mRNA levels. MATERIAL AND METHODS: HNECs were stimulated with recombinant human TNF-alpha (20 pg/mL-20 ng/mL) for specified time periods (0, 12, 24, and 48 h) and ICAM-1 mRNA and the soluble ICAM-1 (sICAM-1) concentrations were measured by quantitative RT-PCR and ELISA, respectively. We also evaluated surface expression of ICAM-1 by flow cytometry 48 h after stimulation and determined the effect of dexamethasone (DEX) on TNF-alpha-induced ICAM-1 expression. RESULTS: Significant increases in ICAM-1 gene expression in HNECs were initially detected at 24 h, peaking at 48 h after the stimulation. The TNF-mediated-ICAM-1 mRNA and ICAM-1 surface expression at 48 h was significantly inhibited by co-incubation with human recombinant soluble TNF receptor I. Similarly, TNF-alpha-induced release sICAM-1 occurred in a time- and concentration-dependent manner. DEX 10(-6) M attenuated the TNF-alpha-induced ICAM-1 expression at mRNA and protein levels. CONCLUSIONS: Our finding suggests a potential role for topical steroids in allergic rhinitis in suppressing inflammatory reactions in the nasal mucosa by regulating ICAM-1 expression on nasal epithelium.

Adult↗

Role of neuronal glutamate transporter in the cysteine uptake and intracellular glutathione levels in cultured cortical neurons.

Cysteine uptake is the rate-limiting process in glutathione synthesis. Previously we have shown that the inhibitors of excitatory amino acid transporters (EAATs) significantly enhance glutamate toxicity via depletion of intracellular glutathione. In this study we show evidence that the neuronal glutamate transporter EAAT3 is directly enrolled in cysteine uptake in cultured neurons. Neuronal cysteine uptake was dependent on the extracellular sodium, and was suppressed by EAAT inhibitors. Cysteine uptake was suppressed by extracellular glutamate and aspartate, substrates of EAATs, and not by substrates of cysteine transporters. Intracellular glutathione levels were reduced by EAAT inhibitors, and not by inhibitors of cysteine transporters. Knock down of EAAT3 expression using antisense oligonucleotide significantly reduced cysteine uptake, intracellular glutathione level, and neuronal viability against oxidative stress. These facts indicate that EAAT3 functions as a cysteine transporter, and this function seems to be unique and distinct from cysteine transporters that have been reported.

Amino Acid Transport System X-AG↗

Syphilitic cervical lymphadenopathy.

Syphilis is well known as a great mimic, however it is not recognized as a cause of cervical lymphadenopathy. We report a case of a 21-year-old man who presented with marked unilateral cervical lymphadenopathy. He had no evidence of oropharyngeal chancres, skin or genital lesions. Computed tomography (CT) and magnetic resonance (MR) images showed multiple cervical lymphadenopathy, and serologic tests for syphilis were positive. Syphilis should still be a factor for consideration in the differential diagnosis of cervical lymphadenopathy.

Adult↗

Expression and localization of the cysteinyl leukotriene 1 receptor in human nasal mucosa.

BACKGROUND: The cysteinyl leukotrienes (CysLT) are lipid mediators that have been implicated in the pathogenesis of allergic diseases. Pharmacological studies using CysLTs indicate that two classes of receptors, named CysLT1 and CysLT2 receptor, exist. The former is sensitive to the CysLT1 antagonist currently used to treat asthma and allergic rhinitis. Recently, the cDNA for human CysLT1 and CysLT2 receptor have been cloned, making it now possible to study the gene expression of CysLTs receptors. OBJECTIVE: We have used reverse transcription and polymerase chain reaction (RT-PCR) to study the gene expression of CysLT1 and CysLT2 receptor and in situ hybridization to determine the distribution of CysLT1 receptor mRNA in human nasal mucosa. In addition, the distribution of the CysLT1 receptor protein was studied by immunohistochemistry. METHODS: Human turbinates were obtained after turbinectomy from six patients with nasal obstruction refractory to medical therapy. Total RNA was isolated from human nasal mucosa and both CysLT1 and CysLT2 receptor mRNA was detected in these tissues by using RT-PCR. For in situ hybridization study of human nasal mucosa, we used biotin-labelled oligonucleotides probes encoding human CysLT1 receptor cDNA. To identify the cells expressing the CysLT1 receptor protein, double immunostaining was performed by using anti-CysLT1 receptor antibody and monoclonal antileucocyte antibodies. RESULTS: RT-PCR analysis of total nasal RNA demonstrated the expression of both CysLT1 receptor and CysLT2 receptor mRNA. In situ hybridization indicated high levels of CysLT1 receptor hybridization in blood vessels and the interstitial cells, but a sparse signal in airway epithelium and submucosal glands. The immunohistochemical studies revealed that anti-CysLT1 receptor antibody labelled eosinophils, mast cells, macrophages, neutrophils and vascular endothelial cells in the nasal mucosa. CONCLUSION: The results may have an important clinical implication and also promote further investigation of the regulation of CysLT1 receptor in health and disease.

Adolescent↗

Establishment of animal model of antigen-specific T lymphocyte recruitment into nasal mucosa.

DO11.10 transgenic mice, expressing an ovalbumin (OVA)-specific alphabeta T-cell receptor (TCR), have been used as a model of various immune diseases associated with T lymphocytes. Some studies of immunoresponse in lung have involved adoptive transfer of DO11.10 mice. As of yet, however, there have been no studies of the adoptive transfer model in the upper airway. The purpose of this study was to establish an animal model to clarify the recruitment mechanism and the roles of Th2 cells in allergic rhinitis. In accordance with the adoptive transfer system, we generated Th0, Th1 and Th2 cells from DO11.10 mice and transferred them into wild type BALB/c mice. Following nasal OVA challenge to DO11.10 mice or to the BALB/c mice into which antigen-specific Th2 cells had been transferred, the number of local antigen-specific TCR-positive cells accompanying the local eosinophilia had significantly increased. However, nasal OVA challenge to BALB/c mice into which antigen-specific Th0 or Th1 cells were transferred failed to increase the number of local OVA-specific TCR positive cells. These observations suggest that an antigen-specific homing mechanism of Th2 cells may exist in nasal mucosa. Analysis of this model will assist in the development of new therapeutic strategy, which targets Th2 cells in allergic rhinitis.

Administration, Intranasal↗

Extracellular Toll-like receptor 2 region containing Ser40-Ile64 but not Cys30-Ser39 is critical for the recognition of Staphylococcus aureus peptidoglycan.

Toll-like receptor 2 (TLR2) and CD14 function as pattern recognition receptors for bacterial peptidoglycan (PGN). TLRs and CD14 possess repeats of the leucine-rich motif. To address the role of the extracellular domain of TLR2 in PGN signaling, we constructed CD14/TLR2 chimeras, in which residues 1-356 or 1-323 of CD14 were substituted for the extracellular domain of TLR2, and five deletion mutants of TLR2, in which the progressively longer regions of extracellular TLR2 regions were deleted. PGN induced NF-kappaB activation in HEK293 cells expressing TLR2 but not in cells expressing CD14/TLR2 chimeras. The cells transfected with a deletion mutant TLR2(DeltaCys30-Ile64) as well as TLR2(DeltaCys30-Asp160) and TLR2(DeltaCys30-Asp305) failed to respond to PGN, indicating the importance of the TLR2 region Cys(30)-Ile(64). Although TLR2(DeltaCys30-Ser39) conferred cell responsiveness to PGN, the cells expressing TLR2(DeltaSer40-Ile64) failed to induce NF-kappaB activation. In addition, NF-kappaB activity elicited by PGN was significantly attenuated in the presence of synthetic peptide corresponding to the TLR2 region Ser(40)-Ile(64). From these results, we conclude that; 1) CD14 cannot functionally replace the extracellular domain of TLR2 in PGN signaling; 2) the TLR2 region Cys(30)-Ser(39) is not required for PGN recognition; 3) the TLR2 region containing Ser(40)-Ile(64) is critical for PGN recognition.

Amino Acid Sequence↗

Nuclear BAG-1 localization and the risk of recurrence after radiation therapy in laryngeal carcinomas.

BAG-1 is a multifunctional chaperone modulator may contribute to p53-mediated cell cycle arrest. We attempted to investigate whether BAG-1 expression is correlated with prognosis of laryngeal carcinoma patients after radiotherapy. Immunohistochemical analyses revealed BAG-1 expression was present in all laryngeal carcinomas examined, and its expression pattern varied, i.e. cytoplasmic, nuclear and both these staining types. Patients whose tumors predominantly express nuclear BAG-1 have a significantly poor failure-free survival rate after radiotherapy. We thus propose that nuclear BAG-1 localization is a prediction of unfavorable outcome should radiation therapy be undertaken for laryngeal carcinoma patients.

Biomarkers, Tumor↗

Columnar-cell carcinoma of the thyroid.

A case of columnar-cell carcinoma of the thyroid gland occurring in a 77-year-old female is described. Tracheal deviation and calcified anterior neck lesion were showed in X-ray examination. A computed tomography (CT) scan revealed a soft tissue density mass with calcification of the right thyroid lobe and isthmus. A (99m)Tc scintiscan showed a 'cold' nodule, whereas a (201)Tl scintiscan showed a 'hot' in the right thyroid lobe and isthmus. Subtotal thyroidectomy and dissection of paratracheal adipose tissue were performed after fine needle aspiration cytology (FNA) of the thyroid mass had been done. On the FNA smears, there were many papillary fragments, which contained pseudostratified columnar cells. Histopathologically, the tumor had three different types of neoplasm including papillary carcinoma of usual feature, columnar-cell carcinoma and follicular carcinoma. Transitional changes were observed between columnar-cell carcinoma and follicular carcinoma. The patient has been followed up for 3 years, with no evidence of recurrence or metastasis.

Aged↗

Parasympathetic schwannoma of the submandibular gland.

Schwannomas of the submandibular gland have only been documented sporadically throughout the medical literature. We describe a case of schwannoma of the submandibular gland originating from the submandibular branch of the lingual nerve, which carries the preganglionic parasympathetic nerve fibers. The clinical aspect of this tumor is discussed, followed by a brief literature review.

Autonomic Fibers, Preganglionic↗

Inhibition of phosphatidylinositol-3 kinase/Akt or mitogen-activated protein kinase signaling sensitizes endothelial cells to TNF-alpha cytotoxicity.

Bovine carotid artery endothelial (BAE) cells are resistant to tumor necrosis factor-alpha (TNF), like most other cells. We examined if mitogen-activated protein (MAP) kinase and phosphatidylinositol-3 (PI3) kinase/Akt pathways are involved in this effect. In BAE cells, TNF activates MAP kinase in a MAP kinase kinase 1 (MEK1) manner and Akt in PI3-kinase-dependent manner. Pretreatment with either the MEK1 inhibitor U0126 or PI3-kinase inhibitor LY294002 sensitized BAE cells to TNF-induced apoptosis. Neither U0126 nor LY294002 pretreatment affected TNF-induced activation of NF-kappaB, suggesting that the MAP kinase or PI3-kinase/Akt-mediated anti-apoptotic effect induced by TNF was not relevant to NF-kappaB activation. Both MAP kinase and PI3-kinase/Akt -mediated signaling could prevent cytochrome c release and mitochondrial transmembrane potential (Deltapsi) decrease. PI3-kinase/Akt signaling attenuated caspase-8 activity, whereas MAP kinase signaling impaired caspase-9 activity. These results suggest that TNF-induced MAP kinase and PI3-kinase/Akt signaling play important roles in protecting BAE cells from TNF cytotoxicity.

Animals↗

Coronary flow reserve in angiographically normal coronary arteries with one-vessel coronary artery disease without traditional risk factors.

AIMS: Reduced coronary flow reserve has been reported in patients with traditional risk factors, in particular hyperlipidaemia, despite angiographically normal coronary arteries. However, it is recognized that traditional risk factors do not explain the presence of coronary atherosclerosis in a large proportion of patients. The aim of this study was to assess whether coronary flow reserve is preserved in the myocardium supplied by normal coronary arteries in patients with one-vessel coronary artery disease without traditional risk factors. METHODS AND RESULTS: Positron emission tomography using [13N]ammonia was performed at baseline and after intravenous dipyridamole administration (0.56 mg x dl(-1)over 4 min) in 30 subjects: six patients with ischaemia on effort, no myocardial infarction, and isolated left anterior descending coronary artery stenosis without traditional risk factors (coronary artery disease patients without risk factors, aged 59+/-13), five patients with ischaemia on effort, no myocardial infarction, and isolated left anterior descending coronary artery stenosis with multiple risk factors (coronary artery disease patients with risk factors, aged 69+/-7), 11 age-matched controls (aged 58+/-6), and eight healthy young volunteers (aged 34+/-4). Myocardial blood flow calculated in the myocardium supplied by normal coronary arteries in the coronary artery disease patients was compared with those of the two control groups. Coronary flow reserve was defined as the ratio of hyperaemic blood flow after dipyridamole infusion to baseline blood flow. Although coronary flow reserve in the coronary artery disease patients with risk factors was significantly lower than that in the age-matched controls (1.62+/-0.37, 2.58+/-0.71, P=0.0428), coronary flow reserve in the coronary artery disease patients without risk factors was similar to that in the age-matched controls (2.54+/-0.17 vs 2.58+/-0.71, P=ns). CONCLUSION: Coronary flow reserve is preserved in regions supplied by angiographically normal coronary arteries with one-vessel coronary artery disease without traditional risk factors.

Adult↗

Cardiac dysfunction because of secondary hemochromatosis caused by congenital non-spherocytic hemolytic anemia.

Most patients diagnosed with secondary hemochromatosis have had repeated blood transfusions. Cardiac failure accounts for approximately one-third of the deaths associated with hemochromatosis. Liver dysfunction or hormonal disorders such as diabetes generally precede cardiac failure. A 23-year-old woman with hemochromatosis had, despite significant left ventricular dysfunction, liver function within the normal range on biochemical evaluation. She was treated for congestive heart failure and given desferoxamine intravenously. She did not have primary hemochromatosis, and had not received multiple blood transfusions or iron supplement. As a child the patient had been diagnosed with congenital non-spherocytic hemolytic anemia not requiring transfusion; thus, this is a unique case of secondary hemochromatosis.

Adult↗

[The pollen survey and dynamic statistics of patients with allergic rhinitis in Hakodate].

We have investigated the pollen survey (1994-1998) and dynamic statistics of patients with allergic rhinitis (1999-2000) in Hakodate, which is located southern part of Hokkaido. We have noted the pollen dispersion of Cryptomeria japonica, Cupressaceae, white birch, Gramineae and Artemisia. Especially, a lot of dispersion of Cryptomeria japonica has been noted in April. Concerning the dynamic statistics of patients with allergic rhinitis, we have investigated the 192 patients with allergic rhinitis in Hakodate municipal hospital. There has been a lot of pollinosis in March, April, May and September. Frequency of positive reaction to the specific IgE have been 38.0% of house dust, 16.9% of Artemisia, 13.2% of Gramineae, 10.3% of white birch, 9.0% of Cryptomeria japonica and 6.9% of cat in 379 subjects. In conclusion, we have noted that Cryptomeria japonica and white birch in addition to Gramineae and Artemisia are becoming more important antigen in patients with pollinosis in Hakodate, south part of Hokkaido.

Female↗

Induction of hepatocyte growth factor (HGF) in rat microglial cells by prostaglandin E(2).

Hepatocyte growth factor (HGF) is a multifunctional protein that exerts trophic effects on neural cells. HGF is expressed in normal brains and increased after brain injury. Recent studies suggest that neurons and astrocytes are the main producers of HGF in the brain. Here we report that microglia also produce HGF both in vitro and in vivo. Treatment of cultured microglia with prostaglandin E(2) (PGE(2)), one of the major inflammatory mediators in the brain, induced significant production of HGF, and this induction was suppressed by pretreatment with the adenylate cyclase inhibitor SQ22536, suggesting that the induction of HGF by PGE(2) in microglia proceeds via a cAMP-mediated pathway. We further investigated whether microglia also produce HGF in vivo under the pathological condition of cerebral ischemia. We found that HGF expression was increased after permanent occlusion of the middle cerebral artery (MCA), and double immunohistochemical staining revealed that the most of HGF-positive cells were microglia. PGE(2) level was increased 8 hr after start of MCA occlusion, and this enhancement is in parallel with the increase in HGF expression, suggesting that PGE(2) not only may induce HGF production in microglia in vitro but may also be an inducer in vivo.

Adenine↗

A role for p27/Kip1 in the control of cerebellar granule cell precursor proliferation.

During development, control of proliferation of neuronal precursor cells plays a crucial role in determining the number of neurons. Proliferation is driven by mitogens, but how it is terminated remains a mystery. In this study, we examined the role of cyclin-dependent kinase inhibitors in the control of proliferation of cerebellar granule cell precursors (GCPs). Among the inhibitors we examined, only p27/Kip1 (p27) was expressed at significant levels in cells of the granule cell lineage in the developing and adult cerebellum. In developing cerebella, p27 was expressed in the external germinal layer (the deeper regions), the molecular layer, and the granule layer. In adult cerebella, p27 was expressed in the cells of the granule layer. We isolated and purified GCPs from cerebella of developing mice and examined their bromodeoxyuridine (BrdU) uptake and p27 expression at various times. We found that there was an inverse correlation between BrdU uptake and p27 expression. Even in the presence of saturating amounts of Sonic hedgehog, a potent mitogen, the cells eventually stopped dividing and differentiated, expressing p27 strongly. We also examined mice in which one or both copies of the p27 gene have been inactivated by targeted gene disruption and found that their cerebella were larger than those of wild-type mice. In cell cultures, GCPs prepared from p27-deficient mice showed enhanced proliferation compared with GCPs from wild-type mice. Taken together, these results suggest that there is an intracellular mechanism that stops GCP division and causes GCPs to differentiate and that p27 is part of this mechanism.

Age Factors↗

Hepatocyte growth factor protects cultured rat cerebellar granule neurons from apoptosis via the phosphatidylinositol-3 kinase/Akt pathway.

Recent studies suggest that hepatocyte growth factor (HGF) functions as a neurotrophic factor in the central nervous system. In this study, we investigated the neuroprotective effect of HGF and its mechanism of action. We used cultured cerebellar granule neurons that underwent apoptosis when the culture medium was changed from that containing serum with 25 mM K(+) to serum-free medium containing 5 mM K(+), and HGF prevented apoptotic cell death. HGF stimulated both mitogen-activated protein (MAP) kinase and phosphatidylinositol-3 (PI3)-kinase activity in cerebellar granule neurons. Two specific inhibitors of PI3-kinase, wortmannin and LY294002, efficiently blocked this neuroprotective effect of HGF. In contrast, PD98059, a selective inhibitor of MAP kinase kinase (MEK), did not affect the anti-apoptotic effect of HGF. The downstream signal of PI3-kinase in this protection was further investigated. HGF-induced phosphorylation of Akt and pretreatment of the cells with wortmannin completely impaired Akt activation. These results suggest that HGF prevents apoptosis in cerebellar granule neurons via the PI3-kinase/Akt pathway.

Animals↗