Biomedical subjects

T Hirose

Publications and source records attributed to T Hirose.

At least 145 records · Page 8Linked to original sources

PubMed1998

Effect of PAF receptor antagonists on adrenocortical secretion induced by ACTH in normal and athymic nude mice.

The effect of SM12502 and CV6209, platelet-activating factor (PAF) receptor antagonists on corticosterone (B) secretion induced by ACTH was examined in the perfused adrenals of CD1 ICR (normal) and CD1 ICR nu/nu (athymic) mice. Bilateral adrenals were perfused in situ with an artificial medium equilibrated by 95% O2 + 5% CO2. Continuous infusion of 10 microM SM12502 or CV6209 inhibited the B response to 100 pg/ml ACTH markedly in normal mice but insignificantly in athymic mice. Infusion of PAF did not significantly affect B secretion in either normal or athymic mice. Administration of 0.1 microM of N-methylcarbamyl PAF, a nonmetabolizable PAF agonist, significantly increased B secretion in normal mice, but not in athymic mice. Infusion of SM12502 significantly depressed the B response to 10 microM forskolin or 1 mM dibutyryl cyclicAMP (cAMP) in normal mice, but not in athymic mice. The results indicate that endogenous PAF and its receptor may play a role in the ACTH-initiated signaling pathway at the phase after responsiveness to cAMP and its receptor may have little function in athymic mice.

Adrenal Cortex↗

PubMed1998

The Fc receptor (FcR) gamma subunit is essential for IgE-binding activity of cell-surface expressed chimeric receptor molecules constructed from human high-affinity IgE receptor (Fc epsilon RI) alpha and FcR gamma subunits.

The Fc receptor (FcR) gamma subunit was originally discovered as a homodimeric subunit of the high-affinity IgE receptor (FcepsilonRI). But it was recently found to be a common signal-generating subunit of Fc receptors including IgG Fc receptors (FcgammaRs) and IgA Fc receptor (FcalphaR), and furthermore to generate a signal also with stimuli through non-immune receptors. In addition, it plays an essential role in cell-surface expression of the FcepsilonRI and the FcgammaRIIIA isoform and also regulates cell-surface expression and ligand-binding affinity of the FcgammaRI. In this report, we addressed the possibility that the FcRgamma could affect the correct folding of the IgE-binding region of the FcepsilonRIalpha subunit by using the chimeric receptor molecules constructed from human FcepsilonRIalpha and FcRgamma. Furthermore, we demonstrated that the seven amino acid residues in the C-terminal region on the extracellular domain of the FcepsilonRlalpha were essential for maintaining the IgE-binding activity of the FcepsilonRIalpha exodomain on the cell membrane and/or may affect the correct folding of the alpha subunit itself within the cell.

Animals↗

PubMed1998

Exposure of hepatic sinusoidal mononuclear cells to UW solution in situ but not ex vivo induces apoptosis.

BACKGROUND/AIMS: We have previously reported that human hepatic sinusoidal mononuclear cells may have a higher sensitivity to induction of apoptosis than peripheral blood mononuclear cells. In this study, the effects of two different preservation solutions on the functions of those hepatic mononuclear cells were evaluated in living-related liver transplantation. METHODS: Ten and 11 liver grafts were perfused via the portal vein with University of Wisconsin solutions (UW group) and Bretschneider's Histidine-Tryptophan-Ketoglutarate solutions (HTK group), respectively. Hepatic mononuclear cells were isolated from the effluent preservation solution passing through the graft livers. Cytofluorometry, cytotoxic assay, and DNA analysis were performed. RESULTS: There were no significant differences in surface antigens and natural killer activity of hepatic sinusoidal mononuclear cells between the UW and HTK groups. At the time of isolation, the viability of hepatic sinusoidal mononuclear cells in both groups was more than 99%. In the UW group, the viability of hepatic sinusoidal mononuclear cells decreased to 30% through apoptosis in in vitro culture at 48 h after isolation. In the HTK group, however, their viability was maintained at more than 90% at 48 h in the same culture conditions, and additional exposure to UW solution ex vivo for 30 min did not induce apoptosis. CONCLUSION: Hepatic sinusoidal mononuclear cells isolated from the UW solution, not from the HTK solution, passing through the liver died through apoptosis, which was not induced by each component of the UW solution, but by exposure in situ.

Adenosine↗

PubMed1998

Differential effects on D2 dopamine receptor and prolactin gene expression by haloperidol and aripiprazole in the rat pituitary.

[3H]Spiperone-binding assay to D2 receptors and quantitative ribonuclease protection assay for both isoforms (D2L and D2S receptor) of the D2 receptor mRNA and the prolactin mRNA were performed on pituitaries from the control rat and from the rat injected orally daily with either haloperidol (2 mg/kg) or aripiprazole (24 mg/kg) for 21 days. Haloperidol treatment increased the [3H]spiperone-binding by 28%, the levels of D2L and D2S receptor mRNA by 41% and 38%, respectively, and the level of prolactin mRNA by 26%. In contrast, the treatment with aripiprazole, a newly developed atypical antipsychotic with reduced side effects, decreased the [3H]spiperone-binding by 24% and the levels of D2L and D2S receptor mRNA by 23% and 23%, respectively, and did not have any effect on the level of prolactin mRNA. The same treatment with sulpiride (100 mg/kg) increased the levels of D2L and D2S receptor mRNA by 59% and 62%, respectively, but treatment with clozapine (25 mg/kg) did not cause any effect. Neither treatment changed the ratio of the level of D2S receptor mRNA to the level of D2L receptor mRNA in the pituitary. These findings indicate that D2 receptor densities in the pituitary are influenced differentially by the treatment with these antipsychotics, which could be induced at least partly by the changes in the levels of mRNA without any effects on the splicing mechanisms and thus affect the plasticity of the prolactin mRNA expression. The inhibitory effects of chronic aripiprazole treatment on D2 receptors in the pituitary might underlie this drug's clinical property of reduced hyperprolactinemia side effect.

Administration, Oral↗

PubMed1998

Visual Ability Score -- a new method to analyze ability in visually impaired children.

PURPOSE: We analyzed the correlation between the Preferential Looking (PL) acuities and the Visual Ability Scores (VAS) of 600 patients (many with severe retinopathy of prematurity) to determine their ability to perform various activities within the daily environment. METHODS: Visual acuity was measured by PL. Sixteen visual activities within the environment were analyzed. The VAS (range, 1-16) were calculated from the results of each activity and correlated with PL acuity. RESULTS: The PL acuities of the 600 patients ranged from 20/20 (1.0) to <20/3200 (0.006) [mean, 20/337(006)]. The VAS ranged from 1 to 16 points (mean, 10.65; SD, +/-4.80) and showed a high correlation with the PL acuities (r=0.917, p=0.0001). CONCLUSIONS: In addition to PL vision testing, analyzing the environmental visual behavior of young, severely visually impaired patients is important to accurately evaluate visual abilities. We found the VAS to be an important aid for low-vision specialists, especially for those with no access to a vision evaluation system such as PL.

Activities of Daily Living↗

PubMed1998

C677T polymorphism in methylenetetrahydrofolate reductase gene and psychoses.

A common missense mutation of the methylenetetrahydrofolate reductase (MTHFR) gene (C677T) has been shown to be a risk factor for premature cardiovascular disease and neural tube defect. Deficient activity of MTHFR has also been implicated in the pathogenesis of psychiatric conditions such as schizophrenia and affective disorders. Arinami et al found an increased frequency of homozygosity for the mutated type (T677) of the MTHFR gene in schizophrenia and depression. We tried to replicate this finding in a sample of 343 patients with schizophrenia, 143 with bipolar disorder, 71 with unipolar depression, and 258 controls; however, there was no significantly increased frequency of homozygosity for the T677 allele in any of the diagnostic groups, compared to the controls. Our results suggest that homozygosity for the T677 allele of the MTHFR gene is unlikely to play a major role in the pathogenesis of schizophrenia or affective disorders in our sample.

Adult↗

PubMed1998

N-acetylcysteine improves cytotoxic activity of cirrhotic rat liver-associated mononuclear cells.

Liver cirrhosis, which is associated with decreased plasma and hepatic glutathione (GSH), has been reported to cause the suppression of NK activity in peripheral blood mononuclear cells. Since low GSH levels in lymphocytes are known to alter lymphocyte function, we examined the correlation between intracellular GSH levels and the cytotoxic activity of liver-associated mononuclear cells (liver MNC). We show here that rat liver contains a highly active population of NK cells (CD3- NKR-P1 + cells) that kill Yac-1 in vitro and that the cytotoxic activity of this NK population is directly proportional to liver MNC GSH. This proportionality is independent of the methods used to alter GSH level. Thus, in vitro treatment of liver MNC with buthionine sulfoximine to lower GSH levels lowers the cytotoxic activity. MNC from cirrhotic liver, in which implanted tumor cells grow faster, have both low GSH levels and low cytotoxicity, and supplementation of cirrhotic liver MNC with N-acetylcysteine raises GSH levels and increases cytotoxicity. These findings suggest a physiologic mechanism, i.e. decreased GSH, may be causally associated with the increased incidence of hepatoma in cirrhotic individuals and the increased growth of hepatoma cells in cirrhotic animals. Thus, we suggest that the GSH is important to the optimal functioning of the hepatic immunity that protects against hepatoma development.

Acetylcysteine↗

PubMed1998

Frequent expression of bcl-2 protein in solitary fibrous tumors.

The distinction of solitary fibrous tumors from histologically similar neoplasms is often difficult because they rarely occur at a variety of extrapleural sites. CD34 immunoreactivity has recently been recognized to be an adjunct for the diagnosis of solitary fibrous tumors. However, it is now known that CD34 staining is not entirely specific for this entity. We evaluated 23 solitary fibrous tumors and 54 other spindle cell tumors often considered in the differential diagnosis for immunoreactivity using monoclonal antibodies directed against bcl-2 protein, which protects cells from apoptosis and CD34. The patients with solitary fibrous tumors comprised 11 men and 12 women, ranging in age from 35 to 85 years (mean, 57.6 years). Fourteen tumors arose in the pleura, four in the retroperitoneum, three in the superficial soft tissue and one each in the mediastinum and uterine cervix. Nineteen of 23 solitary fibrous tumors (83%), irrespective of tumor site, demonstrated diffuse cytoplasmic staining for bcl-2 protein. bcl-2 immunoreactivity was also observed in five of seven neurofibromas (71%), eight of 10 synovial sarcomas (80%) and one of three spindle cell lipomas (33%). CD34 immunoreactivity was present in all but one solitary fibrous tumor (96%), seven of seven neurofibromas (100%), three of three spindle cell lipomas (100%), five of five dermatofibrosarcomas (100%), three of three hemangiopericytomas (100%) and two of seven malignant fibrous histiocytomas (29%). To date, most of the pleural and extrapleural cases have not shown aggressive features. We suggest that bcl-2 protein can be used together with CD34 in the diagnosis of solitary fibrous tumor to distinguish this entity from other spindle cell neoplasms.

Adult↗

PubMed1998

Chemical modification of L-phenylalanine oxidase from Pseudomonas sp. P-501 by phenylglyoxal. Identification of one essential arginyl residue.

L-Phenylalanine oxidase from Pseudomonas sp. P-501 was irreversibly inactivated by the arginine-specific reagents, phenylglyoxal (PGO) and p-hydroxyphenylglyoxal (HPG). The inactivation by PGO and HPG follows pseudo-first-order kinetics with second-order rate constants of 10.6 and 15.1 M-1.min-1, respectively, and a single arginyl residue was modified specifically. The effective protection by substrate L-phenylalanine against the inactivation by these reagents strongly suggests that the arginyl residue is located in the substrate binding site. SDS/PAGE analysis of the enzyme modified with [14C]PGO revealed that the arginyl residue was in the beta subunit of the enzyme. The fragment containing the 14C-labeled arginyl residue was purified from the enzymatic digests of the labeled beta subunit by HPLC and sequenced. The modification of Arg-35 in the beta subunit was identified. The sequence around Arg-35 shows homology to the corresponding regions of tryptophan-2-monooxygenases.

Amino Acid Oxidoreductases↗

PubMed1998

Perineurial malignant peripheral nerve sheath tumor (MPNST): a clinicopathologic, immunohistochemical, and ultrastructural study of seven cases.

Most malignant peripheral nerve sheath tumors (MPNST) are schwannian in nature. The pathologic features of MPNST with perineurial cell differentiation remain to be characterized. To determine the clinicopathologic, immunohistochemical, and ultrastructural characteristics of perineurial MPNST, 121 MPNST from the Mayo Clinic Tissue Registry were examined. Of these 23 spindle cell tumors with long processes disposed in whorls or storiform patterns, features typical of perineurioma, were studied. On the basis of immunohistochemistry (epithelial membrane antigen+/S-100-), 5 perineurial MPNST were identified among 23 tumors selected. These and two previously characterized perineurial MPNST are the subject of this study. None of seven tumors was associated with NF-1. Patients included five males and two females ranging in age from 11 to 83 years (mean, 45.7 years). The tumors measured 1.5 to 30 cm (mean, 9.1 cm) and arose in the extremities (two), trunk (two), face (one), mediastinum (one), and retroperitoneum (one). Only one tumor was nerve associated (phrenic nerve). All tumors were surgically removed. No encapsulation or neurofibroma components were noted. Necrosis was seen in three lesions. Four tumors were classified as high-grade malignant and three as low grade. Mitotic indices varied from 1 to 85/10 high-power fields (median, 16). Immunoreactivities included epithelial membrane antigen (100%), vimentin (100%), Leu-7 (57%), and CD34 (14%). Stains for S-100 protein, muscle markers, and cytokeratin were nonreactive. Ultrastructurally, perineurial-like cells were noted in three tumors and cells intermediate between perineurial and Schwann cells in one. Four tumors recurred and two metastasized; no deaths of disease were noted at follow-ups of 28 to 98 months (mean, 66.9). In conclusion, 4% of MPNST show perineurial cell differentiation. An NF-1 association has yet to be described. Nerve involvement is infrequent. Their immunophenotype (epithelial membrane antigen+/S-100-) frequently indicates ultrastructural perineurial differentiation. The prognosis of perineural MPNST appears to be more favorable than that of conventional MPNST.

Adult↗

PubMed1998

Helical computed tomography diagnosis of pleural dissemination in lung cancer: comparison of thick-section and thin-section helical computed tomography.

Pleural dissemination in lung cancer was prospectively evaluated by helical computed tomography (CT), and the usefulness of thick-section CT (10-mm collimation; pitch 1) and thin-section CT (2-mm collimation; pitch 1) were compared. The study included 54 patients with pulmonary adenocarcinoma in whom plain chest radiographs showed no evidence of pleural effusion and in whom the primary lesion was seen to be contiguous with the pleural surface on thick-section CT. Thin-section CT was performed for evaluation of the costal, mediastinal, interlobar, and diaphragmatic pleural surfaces. Pathologic examination revealed pleural dissemination in 20 patients (8 resected, 12 nonresected). Pleural dissemination was diagnosed in 12 patients on thick-section CT, and in 20 patients on thin-section CT. False negatives occurred in ten and two patients, respectively. The same two patients were false positives by both methods. Accuracy was 78% for thick-section CT and 93% for thin-section CT, and sensitivity was 50% and 90%, respectively. Thin-section CT provided more useful information than thick-section CT for the evaluation of pleural dissemination in lung cancer.

Adenocarcinoma↗

PubMed1998

Cyanoacrylate glue in the repair of retinal detachment associated with posterior retinal breaks in infants and children.

PURPOSE: To share the authors' experience with cyanoacrylate glue in posterior retinal breaks associated with retinal detachments in infants and children. METHODS: A retrospective study was performed of four consecutive pediatric patients who underwent vitreoretinal surgery for retinal detachment associated with posterior retinal breaks, for which cyanoacrylate glue was used. RESULTS: In three of the four patients, successful retinal reattachment with visual function was achieved by vitreoretinal surgery and cyanoacrylate placed on the apposed edges of posterior retinal breaks or used to plug a break (postoperative follow-up was 1.5-2 years). In two successful cases, the glue was applied onto the break while the retina was detached, which resulted in closure of the retinal breaks and reattachment of the retina in both cases. CONCLUSIONS: Cyanoacrylate creates a permanent closure of retinal breaks and may be useful in select cases of infant retinal detachment with posterior retinal breaks in which current available treatment failed or would fail.

Administration, Topical↗

PubMed1998

Carbonic anhydrase activity and CO2-transfer resistance in Zn-deficient rice leaves

It has been reported that carbonic anhydrase (CA) activity in plant leaves is decreased by Zn deficiency. We examined the effects of Zn deficiency on the activity of CA and on photosynthesis by leaves in rice plants (Oryza sativa L.). Zn deficiency increased the transfer resistance from the stomatal cavity to the site of CO2 fixation 2. 3-fold and, consequently, the value of the transfer resistance relative to the total resistance in the CO2-assimilation process increased from 10% to 21%. This change led to a reduced CO2 concentration at the site of CO2 fixation, resulting in an increased gradient of CO2 between the stomatal cavity and this site. The present findings support the hypothesis that CA functions to facilitate the supply of CO2 from the stomatal cavity to the site of CO2 fixation. We also showed that the level of mRNA for CA decreased to 13% of the control level during Zn deficiency. This decrease resembled the decrease in CA activity, suggesting the possible involvement of the CA mRNA level in the regulation of CA activity.

Journal Article↗

PubMed1998

Gliosarcoma: an immunohistochemical, ultrastructural and fluorescence in situ hybridization study.

Three cases of primary gliosarcoma (GS) were studied by immunohistochemical, ultrastructural and fluorescence in situ hybridization (FISH) methods. All tumors occurred in the supratentorial regions of the body. No patient had a prior history of irradiation to the brain. All patients died of tumor within 1 year, and autopsies were performed in two cases. Microscopically, each of the three tumors showed a mixture of glioblastoma (GBM) and a sarcomatous component (SC), which resembled fibrosarcoma with various histological features. Numerous collagen and reticulin fibers were seen in the SC of all tumors. Glial fibrillary acidic protein (GFAP) was immunoreactive only in the gliomatous component (GC). Factor VIII-related antigen was negative except for endothelial cells. One tumor exhibited alpha-smooth muscle actin positivity in the SC. Expression of MIB-1 and p53 protein was demonstrated in both components for all tumors. Labeling indices (LI) for MIB-1 ranged from 7.7 to 36.1%, and LI for p53 protein ranged from 2.9 to 57.0%. Ultrastructurally, astrocytic cells were characterized by a polygonal configuration with many cytoplasmic projections and occasional filaments. Spindle-shaped fibroblasts in the SC contained well-developed rough endoplasmic reticulum. Fluorescence in situ hybridization (FISH) performed on fresh materials or paraffin-embedded tissue demonstrated single signals for chromosome 10 in 40.6-58.3% of cells and for chromosome 17 in 37.9-48.6% of cells. Two tumors were regarded as containing losses of both chromosomes 10 and 17, while the third showed a substantial loss only of chromosome 10. As similar aberrations have been reported in GBM, these chromosomal abnormalities suggest a common pathogenesis in GS and GBM.

Actins↗

PubMed1998

Adenosarcoma of the uterine cervix presenting as a cervical polyp.

A case of adenosarcoma arising from the uterine cervix of a 55-year-old female who complained of vaginal discharge is reported. A polyp, 6 x 2 x 1.5 cm in size, identified in the cervical canal was clinically diagnosed as benign cervical polyp and resected. Histologically, the polyp was composed of benign epithelial components and sarcomatous stroma wherein periglandular hypercellularity and some mitoses including atypical ones were noted. Immunohistochemically, stromal cells were positive for muscle-type actins, desmin and estrogen receptor. Adenosarcoma is a rare, biphasic tumor of the uterus and usually presents as a polypoid mass in the endometrial cavity. When they arise from the cervix, adenosarcomas may be confused with benign cervical polyps clinically and pathologically. As the former often recurs, microscopic differentiation is crucial for further treatment.

Actins↗

PubMed1998

Metastatic cervical carcinoma mimicking kidney abscess.

A 26-year-old female, who had been treated for cervical carcinoma, presented with high fever and right flank pain. A right renal abscess was initially suspected from the clinical symptoms and diagnostic imaging. However, pathologic findings for the right kidney revealed squamous cell carcinoma, which was consistent in type with the original cervical carcinoma. Demonstration of human papillomavirus 16 in tissues from both the renal tumor and the cervical carcinoma confirmed that the right kidney carcinoma was a metastasis from the cervical carcinoma. The role of interleukin-6 in occurrence of the unexplained fever is discussed.

Abscess↗

PubMed1998

Ileal neobladder for bladder substitution after radical cystectomy.

BACKGROUND: Studer's ileal neobladder is technically simple, and favorable clinical results have been reported. However, there have been only a few follow-up studies on this type of ileal neobladder. We reviewed the clinical outcomes of patients who received Studer's ileal neobladder, with a minor modification, in our institution. METHODS: Twenty-five men underwent bladder reconstruction with Studer's ileal neobladder after radical cystectomy. The function of the ileal neobladder and voiding status were evaluated during follow-up. The follow-up period ranged from 3 to 42 months (mean, 24 months). RESULTS: The ileal neobladder achieved a large capacity at a low basal pressure, associated with a relatively low complication rate directly related to the neobladder. At 12 months after surgery, daytime and nighttime continence rates were 90% and 74%, respectively. In 5 patients who were incontinent, the maximal urethral closure pressure was statistically lower than in patients with continence. CONCLUSION: Studer's ileal neobladder is an easy operative procedure for bladder substitution, and has a relatively low complication rate directly related to the neobladder. Good compliance of the pouch and preservation of the external sphincter mechanism are the most important factors for achieving urinary continence, after construction of the ileal neobladder.

Adult↗

PubMed1998

Objective measurement of contrast sensitivity function using contrast sweep visual evoked responses.

AIM/BACKGROUND: The contrast sensitivity function (CSF) measurement provides information that is not accessible by standard visual acuity determinations. The contrast sweep pattern reversal visual evoked responses (CSVER) technique was used to objectively measure the CSF in clinical practice. METHODS: The contrast thresholds were measured at five spatial frequencies in 10 normal subjects. The CSVER were recorded with sinusoidally modulated vertical gratings at 10 contrast levels (96, 64, 48, 32, 16, 8, 4, 2, 1, and 0.5%) presented in five spatial frequencies (0.5, 1.0, 2.0, 4.0, and 8.0 cycles per degree). Each of 10 contrast levels was displayed for 2 seconds at the desired spatial frequency. The CSVER amplitudes at the second harmonic were calculated by discrete Fourier transform. The results were compared with those obtained using a psychophysical method. RESULTS: An inverted U-shaped CSF which peaked at 2.0 cycles per degree with a contrast sensitivity of 34.5 (contrast, 2.9%) was observed. The CSF assessed electrophysiologically was 0.62 to 0.79 log units lower than the sensitivity measured using the psychophysical method. However, the overall shapes were highly correlated. CONCLUSION: One can objectively measure CSF with CSVER and this may be useful in patients in whom the psychophysical method is limited.

Adult↗