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T Hirose

Publications and source records attributed to T Hirose.

At least 37 records · Page 2Linked to original sources
PubMed2001

Tumor imprint cytology of ovarian ependymoma. A case report.

BACKGROUND: Ependymoma is a tumor that usually develops in the central nervous system and is extremely rare in the ovary. The first case of ovarian ependymoma was reported by Kleinman et al. (Kleinman GM, Young RH, Scully RE. Ependymoma of the ovary: report of three cases. Hum Pathol 1984;15:632-8.) in 1984, and only eight cases have been reported since then. Criteria for the histopathologic diagnosis of ependymoma are already established, but there has been no investigation of the cytologic diagnosis of ovarian ependymoma. METHODS: An imprint cytologic specimen was obtained from a recurrent ovarian ependymoma. The imprint cytologic features were compared with the findings of histologic examination, immunostaining, and electron microscopy. RESULTS: Imprint cytology revealed clusters of small cells with tapering cytoplasmic processes and a round nucleus. On the basis of these features, a neurogenic tumor could be included in the differential diagnosis. Furthermore, many rosette-like collections of cells that were suggestive of ependymal rosettes or perivascular pseudorosettes, characteristic of ependymoma, were found. The presence of ependymal rosettes and perivascular pseudorosettes also were confirmed by the histopathologic examination. Together with positive immunostaining for glial fibrillary acidic protein, this led to the diagnosis of ependymoma, which also was supported by the electron microscopic findings. CONCLUSIONS: Careful observation of the imprint cytologic specimen of an ovarian ependymoma should reveal numerous rosette-like collections of cells that were suggestive of ependymal rosettes or perivascular pseudorosettes. In addition, if we remember that ependymoma can develop in the ovary and find cells with tapering processes that suggest a neurogenic tumor, it may be possible to detect histologic features characteristic of ependymoma by the imprint cytology. To our knowledge, this is the first report on the imprint cytologic diagnosis of ependymoma originating in the ovary.

Adult↗
PubMed2001

Simultaneous topographic and fluorescence imaging of single DNA molecules for DNA analysis with a scanning near-field optical/atomic force microscope.

High-resolution fluorescence imaging of lambda-phage DNA molecules, intercalated with the dye YOYO-1, has been performed by a SNOM/AFM based on a bent-type optical fiber probe. A modified design of the optical probe has been made, and successful near-field optical resolution has been obtained for the strongly stretched lambda-phage DNA molecules. The best optical resolution was estimated at 45 nm for the dye-intercalated single lambda-DNA molecules by a mean width evaluation. In our comparison between the far-field fluorescence and high-resolution near-field fluorescence images for the DNA, it has been found that the near-field images much better defined the intercalation state of the dye. Finally, the relation between the DNA shapes and the dye distribution states, and the discrimination between the double-stranded and single-stranded DNA molecules, are discussed by comparing the topography and fluorescence images of the SNOM/AFM.

Benzoxazoles↗
PubMed2001

LDL receptor-related protein 5 (LRP5) affects bone accrual and eye development.

In humans, low peak bone mass is a significant risk factor for osteoporosis. We report that LRP5, encoding the low-density lipoprotein receptor-related protein 5, affects bone mass accrual during growth. Mutations in LRP5 cause the autosomal recessive disorder osteoporosis-pseudoglioma syndrome (OPPG). We find that OPPG carriers have reduced bone mass when compared to age- and gender-matched controls. We demonstrate LRP5 expression by osteoblasts in situ and show that LRP5 can transduce Wnt signaling in vitro via the canonical pathway. We further show that a mutant-secreted form of LRP5 can reduce bone thickness in mouse calvarial explant cultures. These data indicate that Wnt-mediated signaling via LRP5 affects bone accrual during growth and is important for the establishment of peak bone mass.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Lipomatous primitive neuroectodermal tumor with a glioblastoma component: a case report.

A case of extracerebellar lipomatous primitive neuroectodermal tumor (PNET) with glioblastoma multiforme (GBM) areas is reported. A 44-year-old woman who had been on antipsychotic agents for schizophrenia complained of hemiparesis and drowsiness. She deteriorated progressively and died 3 months later. The autopsy revealed a huge, ill-defined tumor located from right basal ganglia to brain stem. Microscopically, the tumor consisted of three distinct components: clusters of small primitive cells consistent with PNET, mature lipoma-like islands, and a GBM-like component. Neuronal differentiation in PNET areas was confirmed by the presence of Homer Wright rosette, synaptophysin-positive fibrillary background, and ultrastructural demonstration of neuritic processes. Lipoma-like areas composed of lipidized cells containing large lipid droplets were intimately intermingled and closely related with PNET areas. Furthermore, GBM areas were, although predominantly located in the brain stem, often blended with the previous two components. This component was characterized by glial fibrillary acid protein immunoreactivity of atypical tumor cells and the presence of necrosis and endothelial proliferation. PNET areas with lipomatous differentiation in the present tumor may suggest the morphological and histogenetic similarity to liponeurocytoma, although the neuronal element in the former was anaplastic. The association with a GBM component makes the present tumor a unique, and, to our knowledge, previously unrecognized lesion.

Adult↗
PubMed2001

Position within the host intron is critical for efficient processing of box C/D snoRNAs in mammalian cells.

In mammalian cells, all small nucleolar RNAs (snoRNAs) that guide rRNA modification are encoded within the introns of host genes. A database analysis of human box C/D snoRNAs revealed conservation of their intronic location, with a preference for 70-80 nt upstream of the 3' splice site. Transfection experiments showed that synthesis of gas5-encoded U75 and U76 snoRNAs dropped significantly for mutant constructs possessing longer or shorter spacers between the snoRNA and the 3' splice site. However, the position of the snoRNA did not affect splicing of the host intron. Substitution mutations within the spacer indicated that the length, but not the specific sequence, is important. A in vitro system that couples pre-mRNA splicing and processing of U75 has been developed. U75 synthesis in vitro depends on its box C and D sequences and requires an appropriate spacer length. Further mutational analyses both in vivo and in vitro, with subsequent mapping of the branch points, revealed that the critical distance is from the snoRNA coding region to the branch point, suggesting synergy between splicing and snoRNA release.

Animals↗
PubMed2001

The cell polarity protein ASIP/PAR-3 directly associates with junctional adhesion molecule (JAM).

The establishment and maintenance of cellular polarity are critical for the development of multicellular organisms. PAR (partitioning-defective) proteins were identified in Caenorhabditis elegans as determinants of asymmetric cell division and polarized cell growth. Recently, vertebrate orthologues of two of these proteins, ASIP/PAR-3 and PAR-6, were found to form a signalling complex with the small GTPases Cdc42/Rac1 and with atypical protein kinase C (PKC). Here we show that ASIP/PAR-3 associates with the tight-junction-associated protein junctional adhesion molecule (JAM) in vitro and in vivo. No binding was observed with claudin-1, -4 or -5. In fibroblasts and CHO cells overexpressing JAM, endogenous ASIP is recruited to JAM at sites of cell-cell contact. Over expression of truncated JAM lacking the extracellular part disrupts ASIP/PAR-3 localization at intercellular junctions and delays ASIP/PAR-3 recruitment to newly formed cell junctions. During junction formation, JAM appears early in primordial forms of junctions. Our data suggest that the ASIP/PAR-3-aPKC complex is tethered to tight junctions via its association with JAM, indicating a potential role for JAM in the generation of cell polarity in epithelial cells.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Atypical protein kinase C is involved in the evolutionarily conserved par protein complex and plays a critical role in establishing epithelia-specific junctional structures.

We have previously shown that during early Caenorhabditis elegans embryogenesis PKC-3, a C. elegans atypical PKC (aPKC), plays critical roles in the establishment of cell polarity required for subsequent asymmetric cleavage by interacting with PAR-3 [Tabuse, Y., Y. Izumi, F. Piano, K.J. Kemphues, J. Miwa, and S. Ohno. 1998. Development (Camb.). 125:3607--3614]. Together with the fact that aPKC and a mammalian PAR-3 homologue, aPKC-specific interacting protein (ASIP), colocalize at the tight junctions of polarized epithelial cells (Izumi, Y., H. Hirose, Y. Tamai, S.-I. Hirai, Y. Nagashima, T. Fujimoto, Y. Tabuse, K.J. Kemphues, and S. Ohno. 1998. J. Cell Biol. 143:95--106), this suggests a ubiquitous role for aPKC in establishing cell polarity in multicellular organisms. Here, we show that the overexpression of a dominant-negative mutant of aPKC (aPKCkn) in MDCK II cells causes mislocalization of ASIP/PAR-3. Immunocytochemical analyses, as well as measurements of paracellular diffusion of ions or nonionic solutes, demonstrate that the biogenesis of the tight junction structure itself is severely affected in aPKCkn-expressing cells. Furthermore, these cells show increased interdomain diffusion of fluorescent lipid and disruption of the polarized distribution of Na(+),K(+)-ATPase, suggesting that epithelial cell surface polarity is severely impaired in these cells. On the other hand, we also found that aPKC associates not only with ASIP/PAR-3, but also with a mammalian homologue of C. elegans PAR-6 (mPAR-6), and thereby mediates the formation of an aPKC-ASIP/PAR-3-PAR-6 ternary complex that localizes to the apical junctional region of MDCK cells. These results indicate that aPKC is involved in the evolutionarily conserved PAR protein complex, and plays critical roles in the development of the junctional structures and apico-basal polarization of mammalian epithelial cells.

Actins↗
PubMed2001

Involvement of a site-specific trans-acting factor and a common RNA-binding protein in the editing of chloroplast mRNAs: development of a chloroplast in vitro RNA editing system.

RNA editing in higher plant chloroplasts involves C-->U conversion at approximately 30 specific sites. An in vitro system supporting accurate editing has been developed from tobacco chloroplasts. Mutational analysis of substrate mRNAs derived from tobacco chloroplast psbL and ndhB mRNAs confirmed the participation of cis-acting elements that had previously been identified in vivo. Competition analysis revealed the existence of site-specific trans-acting factors interacting with the corresponding upstream cis-elements. A chloroplast protein of 25 kDa was found to be specifically associated with the cis-element involved in psbL mRNA editing. Immunological analyses revealed that an additional factor, the chloroplast RNA-binding protein cp31, is also required for RNA editing at multiple sites. This combination of site-specific and common RNA-binding proteins recognizes editing sites in chloroplasts.

Base Sequence↗
PubMed2001

Activation of matrix metalloproteinase-2 is correlated with invasiveness in thymic epithelial tumors.

UNLABELLED: BACKGROUND AND OBJECTS: Matrix degradation, which is a critical event in the process of tumor invasion and metastasis, is considered to be caused by the action of proteolytic enzymes. METHODS: We examined the gelatinolytic activity of matrix metalloproteinase (MMP)-9, and the activity of active and inactive forms of MMP-2 in five thymi, five noninvasive thymomas, eight invasive thymomas, and five thymic carcinomas by quantitative gelatinolytic zymography. RESULTS: The gelatinolytic activity of active MMP-2 in five thymi was zero. The mean gelatinolytic activity of active MMP-2 was 0.020 +/- 0.015 in noninvasive thymoma, 0.084 +/- 0.098 in invasive thymoma and 0.246 +/- 0.194 in thymic carcinoma. The gelatinolytic activity of active MMP-2 correlated with the invasiveness of thymic epithelial tumors (Spearman rank correlation: r-value = 0.532). The gelatinolytic activity of active MMP-2 in three thymoma cases with microscopic capsular invasion was the same as that of noninvasive thymoma. When thymoma cases showing microscopic capsular invasion were classified into the "macroscopically noninvasive thymoma" group, the gelatinolytic activity of active MMP-2 correlated with the invasiveness of thymic epithelial tumors (Spearman rank correlation: r-value = 0.621). CONCLUSIONS: The gelatinolytic activity of active MMP-2 significantly correlated with the invasiveness in thymic epithelial tumors. J. Surg. Oncol. 2001;76:169-175.

Enzyme Activation↗
PubMed2001

Primary ependymoma of the ovary, in which long-term oral etoposide (VP-16) was effective in prolonging disease-free survival.

BACKGROUND: Ovarian ependymoma is an extremely unusual teratoma of the ovary with only eight cases previously reported in the literature worldwide. CASE: A 26-year-old woman presented in 1992 with a sensation of abdominal fullness. The laparotomy revealed ovarian cancer (stage III), which proved to be an ependymoma pathologically. Three courses of the PVP regimen (cisplatin, vinblastine, peplomycin) and pelvic irradiation were administered postoperatively. Oral administration of etoposide (VP-16) was initiated after the residual tumor began to proliferate, and the tumor decreased in size and never regrew during etoposide administration for a total of 5 years and 8 months. The recurrent tumor was observed soon after the drug was discontinued. CONCLUSION: Oral administration of etoposide was effective in prolonging disease-free survival.

Administration, Oral↗
PubMed2001

Angiosarcoma of the breast: report of a case and its findings of MRI.

A 67-year-old woman with angiosarcoma of the left breast is presented. Physical findings showed a hard mass in the left breast with skin discoloration and erythema. Mammography showed a high density shadow in the mass without microcalcification and spicula. On ultrasonography, a hypoechoic mass with an ill-defined boundary was detected. On MRI, the tumor had low signal intensity on T1-weighted images, and higher signal intensity on T2-weighted images. MRI with Gd-DTPA images showed higher signal intensity on T1-weighted images with relatively lower intensity in the central area of the tumor. The artery supplying the tumor derived from the left inner thoracic artery and was visualized on three-dimensional dynamic MRI angiography. Initially misdiagnosed as inflammatory breast cancer, an arterial injection of CPA (100 mg) and 5-FU (500 mg) had been performed preoperatively. The definitive diagnosis of angiosarcoma was established by intraoperative frozen section examination. She underwent modified radical mastectomy and is now free of recurrence. This case emphasizes the difficulties in the clinical diagnosis of angiosarcoma of the breast.

Aged↗
PubMed2001

Neurovisual abnormalities preceding the retinopathy in patients with long-term type 1 diabetes mellitus.

BACKGROUND: Changes in the retina caused by diabetes may lead to visual impairment in dim light, even with good visual acuity and visual fields. To evaluate the visual abnormalities preceding the retinopathy in patients with type 1 diabetes mellitus (DM), we applied electrophysiological methods. METHODS: The visual evoked responses were recorded with sinusoidally modulated vertical gratings at 10 spatial frequencies presented sequentially on a high-resolution monitor in patients with type 1 DM and in normal volunteers. Similarly, the contrast visual evoked responses of 10 contrast levels were recorded at five spatial frequencies. Both amplitudes at the second harmonic were calculated by discrete Fourier transform. The visual acuity and contrast thresholds were determined objectively. RESULTS: There was dissociation between the Snellen and the estimated visual evoked response acuity measurements in patients with diabetes (r2=0.077, P=0.44). The saturation phenomena were observed at lower levels of contrast stimuli than in normal individuals at. 1.0, 2.0, 4.0 and 8.0 cycles per degree (P=0.0001). The contrast sensitivity function was deeply abnormal in all tested patients despite the metabolic control. The values of the area under the curve of the visual evoked response amplitude-contrast level function at five spatial frequencies were smaller in patients with DM than in the control group (P<0.05) at all spatial frequencies tested. CONCLUSIONS: Patients with type 1 DM without retinopathy showed significant lower amplitude of the visual evoked responses at all spatial frequencies tested, with the saturation phenomena observed at lower level of contrast stimuli. In addition, there was a dissociation between the sweep visual evoked responses and the Snellen acuity measurements. A significant and nonselective neuronal visual loss involving the visual pathway precedes the ophthalmoscopically detectable retinopathy in patients with type 1 DM.

Adult↗
PubMed2001

Dynamic changes in protein components of the tight junction during liver regeneration.

The construction of the hepatocyte tight junction is one of the most important events during liver regeneration leading to the reorganization of the bile canaliculi and the repolarization of hepatocytes after cell division. To understand this event at the molecular level, we examined the expression of tight junction proteins by Western blot analysis and their cellular localization by immunofluorescence microscopy in regenerating rat liver after two-thirds hepatectomy. The levels of tight junction components such as claudin-3, ZO-1 and atypical protein kinase C (PKC)-specific interacting protein (ASIP) increased two- to three-fold over control levels in coordination with a peak 2-3 days after partial hepatectomy, whereas occludin levels remained unchanged. The bile canaliculi outlined by tight junction components and actin filaments reveal significant morphological changes from 2-3 days after partial hepatectomy. During this period, claudin-3/ZO-1 and ASIP/ZO-1 were nearly co-localized, whereas occludin was locally reduced or almost absent on the bile canaliculi outlined by ZO-1 staining. The uncoupled localization of F-actin and tight junction components was often observed. The function of hepatocytes, as revealed by the serum bile acids level, was distorted temporally at an early stage of regeneration but mostly restored 3 days after partial hepatectomy. These observations suggest that the de novo construction of tight junctions proceeds mainly 2-3 days after partial hepatectomy in parallel with the cell polarization required for hepatocyte function. However, the complete normalization of the composition of the tight junction components, such as occludin and the association with F-actin, requires additional time, which may support the regeneration of fully polarized normal hepatocytes.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Efficacy of a 14-day course of oral ciprofloxacin therapy for acute uncomplicated pyelonephritis.

This study aimed to evaluate the efficacy and safety of oral antibacterial treatment with fluoroquinilone for acute uncomplicated pyelonephritis Thirteen female patients with acute uncomplicated pyelonephritis were treated with oral fluoroquinilone (ciprofloxacin; CPFX). They received 200 mg of the drug three times a day while febrile (3-5 days). Once they become afebrile, the same dose of the drug, given twice a day, was given for another 9-11 days. The mean duration of the course of CPFX was 14 days. Symptoms were evaluated, and laboratory examinations, including urine culture and measurement of the minimal inhibitory concentration (MIC) of CPFX were conducted before treatment, and 3, 7, 14, 21, and/or 28 days after the initiation of the treatment. Of the 13 patients, only 5 needed to be hospitalized, and the period of hospitalization was only a few days. On the 14th day after the commencement of treatment, bacteriologic and clinical cure rates were 100%. Escherichia coli was the most common uropathogen, being isolated from the urine of 8 patients. No clinical relapse of the disease was found during a follow-up period of up to 4 weeks. The patients tolerated the drug well without developing any serious adverse effects. Oral antimicrobial chemotherapy with fluoroquinolone, given on an outpatient or short-term hospitalization basis, achieved satisfactory bacteriological and clinical outcomes in the treatment of acute uncomplicated pyelonephritis. This treatment regimen is indicated for patients with this disease who are not in a serious condition with complications such as shock.

Acute Disease↗
PubMed2001

Antiplatelet agent cilostazol potentiates adipocyte differentiation of 3T3-L1 cells.

Cilostazol is an antiplatelet drug, which has beneficial effects in treatment of intermittent claudication and decreases serum triacyiglycerol level in these patients. In this study, we examined adipogenic potency of cilostazol using 3T3-L1 preadipocyte cell line because cilostazol is one of the tissue specific phosphodiesterase (PDE) inhibitors. Addition of cilostazol into the differentiation medium including insulin and dexamethasone, induced the adipocyte differentiation without isobutyl methylxanthine (IBMX). Compared with the cells incubated with vehicle, the cells treated with cilostazol contain much more lipid droplets in the cells 6 days after induction of differentiation. Adipocyte specific gene like stearoyl-CoA desaturase was strongly induced after addition of cilostazol. C/EBPbeta, which is induced by IBMX was also induced by cilostazol. These findings suggest a possibility that adipogenic effect of cilostazol is one of the mechanisms, by which this agent decreases blood triacylglycerol level in the intermittent claudication patients.

1-Methyl-3-isobutylxanthine↗
PubMed2001

Effect of thromboxane A2 (TXA2) synthase inhibitor and TXA2 receptor antagonist alone and in combination on antigen-induced bronchoconstriction in guinea pigs.

Thromboxane A2 (TXA2) causes bronchoconstriction and bronchial hyperresponsiveness. Two types of TXA2 modifiers, one synthase inhibitor and one receptor antagonist, are widely used for the treatment of asthma in Japan. Although the target of TXA2 modifiers is to inhibit bioactivity of TXA2, the pharmacological properties are somewhat different between these drugs. We studied the inhibitory effects of the TXA2 synthase inhibitor CS-518 and the TXA2 receptor antagonist S-1452 alone and in combination on antigen-induced bronchoconstriction in passively sensitized guinea pigs treated with diphenhydramine. Both CS-518 and S-1452 inhibited the antigen-induced bronchoconstriction dose-dependently with the plateau. The combination of these drugs at the maximal inhibitory doses did not have any more effect compared with each single dosing. The combination at the submaximal doses tended to show an additive effect, but the effect was not significant. These findings suggest that other prostanoids such as PGE2, PGI2, PGD2 and PGF2alpha may not take an important role in the antiasthmatic effects of TXA2 modifiers.

Animals↗
PubMed2001

Characteristics of type 2 diabetic patients responding to voglibose administration as an adjunct to sulfonylurea.

In this study, we characterized type 2 diabetic patients responding well to the alpha-glucosidase inhibitor voglibose administration as an adjunct to sulfonylurea treatment. Thirty-three type 2 diabetic patients were enrolled in an open prospective study. All the patients had been treated for at least 1 year with a sulfonylurea drug, in whom HbA1c level had been stable for at least 12 weeks. The patients were given voglibose at a dose of 0.2 mg t.i.d. for 12 weeks. Voglibose administration significantly decreased the mean HbA1c level in all the patients at 4, 8, and 12 weeks. Twelve (36%) of the study patients were responders, when the responders were defined as patients whose HbA1c level at 12 weeks fell by at least 1.0% from baseline, or those whose HbA1c level at 12 weeks was < or =7.0%, falling by at least 0.5% from baseline. The baseline fasting plasma glucose (FPG) was significantly lower, and the baseline homeostasis model assessment (HOMA) beta-cell function (HOMA-%beta) was significantly higher in the responders than in the non-responders. There were more patients who had FPG <170 mg/dl and/or HOMA-%beta > or =30% in the responders than in the non-responders (P<0.005). None of the patients with both FPG > or =170 mg/dl and HOMA-%beta >30% responded to the adjunct treatment. These results indicate that baseline FPG and HOMA-%beta are useful clinical markers to predict the effectiveness of the adjunct therapy of voglibose in sulfonylurea-treated type 2 diabetic patients.

Administration, Oral↗