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Biomedical subjects

Y Itoh

Publications and source records attributed to Y Itoh.

At least 289 records · Page 16Linked to original sources
PubMed1998

Localization of vascular endothelial growth factor in synovial membrane mast cells: examination with "multi-labelling subtraction immunostaining".

Mast cells are believed to play a novel part in the development of destructive synovial pannus in rheumatoid arthritis (RA). This study was undertaken to investigate the localization of vascular endothelial growth factor (VEGF) in the synovial membrane using a unique immunostaining technique. Synovial specimens of RA patients were examined immunohistochemically and were compared with specimens from non-RA controls. Multi-labelling subtraction immunostaining, a modification of double- and triple-labelling immunostaining, revealed that the VEGF-positive cells were identical to tryptase-positive cells (mast cells). No other cell types were found to be positive for VEGF. The synovium of RA patients showed a larger number of VEGF-positive mast cells than that of non-RA controls (P<0.001). The study suggests that mast cell-derived VEGF may contribute to the development of synovial pannus in RA.

Arthritis, Rheumatoid↗
PubMed1998

Ultrasound instruments as possible vectors of staphylococcal infection.

In this study, we evaluated whether ultrasound instruments are important in the spread of nosocomial staphylococcal infections. Following genomic typing by pulsed-field gel electrophoresis, it was apparent that ultrasound procedures transferred colonizing staphylococci from a patient's skin to the ultrasound instruments. Staphylococcus aureus survived in the transmission medium for longer than in water. Furthermore, S. aureus was more resistant to the ultrasonic medium than Pseudomonas aeruginosa, also a significant cause of hospital-acquired infections. To prevent staphylococcal transmission by ultrasound equipment, we recommend disinfection of the probe and removal of the medium after each examination.

Cross Infection↗
PubMed1998

The localization of pituitary adenylate cyclase-activating polypeptide (PACAP)-like immunoreactivity in the hypothalamo-pituitary region of an elasmobranch, stingray, Dasyatis akajei.

Pituitary adenylate cyclase activating polypeptide (PACAP), a member of the secretin/glucagon/vasoactive intestinal polypeptide family of peptides, exists as 38-residue (PACAP 38) and truncated 27-residue (PACAP 27) forms, which play various roles in mammals. Recently, we isolated and characterized PACAPs with sequences very similar to that of tetrapod PACAP from the brains of two teleosts, the blue-spotted stargazer Gnathagnus elongatus and the stargazer Uranoscopus japonicus, and located PACAP-like immunoreactivities in the preoptic area, neurohypophysis and medulla oblongata of both species. In this study, PACAP-like immunoreactivity in the brain of an elasmobranch, the stingray Dasyatis akajei, was examined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) and Western blotting analysis and its distribution in the hypothalamo-pituitary region was studied immunohistochemically using the peroxidase-antiperoxidase method. The anti-PACAP 27 serum reacted with a single band of whole brain extract with a molecular weight of ca 5000. PACAP-like immunoreactive (LI) neuronal cell bodies were found in the nucleus medius hypothalami and PACAP-LI nerve fibers and terminals were seen from the nucleus to the caudal floor of the infundibular region. These results suggest that PACAP-like peptide may be present and function as a regulatory factor in the hypothalamo-pituitary region of the elasmobranch brain.

Animals↗
PubMed1998

Therapy-related AML after successful chemotherapy with low dose etoposide for virus-associated hemophagocytic syndrome.

A 19-year-old male patient with virus associated hemophagocytic syndrome (VAHS) began receiving chemotherapy including etoposide (cumulative dose of 900 mg/m2 intravenously) and Ara-C (cumulative dose of 360 mg/m2 intravenously) in July 1994. He achieved complete remission, but developed acute myelomonocytic leukemia (AML, FAB M4) with t(9;11)(p22;q23) in March 1997 and a rearrangement of the MLL gene was also recognized. The MLL gene rearrangement is closely associated with secondary leukemia with an 11q23 translocation. It is highly likely that this case of AML was caused by the cytostatic treatment the patient received, including etoposide for VAHS.

Adult↗
PubMed1998

Assessment of affinities of beta-CIT, beta-CIT-FE, and beta-CIT-FP for monoamine transporters permanently expressed in cell lines.

We investigated the effects of three cocaine analogs, beta-CIT (2-beta-carbomethoxy-3-beta-(4-iodophenyl)-tropane), beta-CIT-FE (2-beta-carbomethoxy-3-beta-(4-iodophenyl)-N-(2.fluoroethyl)-nortropa ne), and beta-CIT-FP (2-beta-carbomethoxy-3-beta-(4-iodophenyl)-N-(3-fluoropropyl)-n ortropane), on the uptake of [3H]dopamine(DA), serotonin(5-HT), and 1-norepinephrine (NE) using cell lines permanently expressing DA, 5-HT, and NE transporters, respectively, to determine their affinities for these three transporters. We generated cell lines stably expressing DA, 5-HT, and NE transporters, respectively, by the Chen-Okayama method, and then tested the abilities of (-)cocaine, beta-CIT, beta-CIT-FE, beta-CIT-FP, and clomipramine to inhibit the uptake of [3H]DA, 5-HT, and 2-NE. Ki values of beta-CIT, beta-CIT-FE, and beta-CIT-FP for [3H]DA, 5-HT, 1-NE uptake were 6, 29, and 33 nM, 91, 133, and 130 nM, and 28, 113 and 70 nM, respectively, whereas those of cocaine and clomipramine were 316, 581, and 176 nM and > 10,000, 437, and 851 nM, respectively. Beta-CIT, beta-CIT-FE, and beta-CIT-FP were shown to be potent DA, 5-HT, and NE uptake inhibitors. Beta-CIT and beta-CIT-FP were highly potent and selective dopamine uptake inhibitors, and therefore might be useful for imaging of DA transporter with single photon emission computed tomography (SPECT) or positron emission tomography (PET).

Animals↗
PubMed1998

TATA sequence requirements for the initiation of transcription for an RNA polymerase II in vitro transcription system from Nicotiana tabacum.

This is the first report to describe the detailed analysis of TATA sequence requirements for the initiation of transcription for RNA polymerase II in a plant in vitro transcription system. We examined the transcriptional activities associated with 24 promoters, including wild-type (TATATATA), and the 21 point and two multiple mutations in tobacco, Drosophila, and HeLa in vitro systems. Although the relative transcriptional activities varied among these promoters, all three systems gave similar results. These results suggest the functional conservation of TATA sequence requirements for in vitro transcription systems among plants, insects, and human.

Animals↗
PubMed1998

An increase in basal glucocorticoid concentration with age induces suppressor macrophages with high-density Fc gamma RII/III.

Ageing is usually accompanied by a decline in immune and neuroendocrine functions. To elucidate the mechanisms underlying age-related immunosuppression, the functions and surface phenotypes of peritoneal cells in the monocyte/macrophage lineage from old mice were investigated. The role of glucocorticoids (GC) in the immunomodulation was also examined. Proliferative responses of spleen cells from control mice stimulated with concanavalin A (Con A) were significantly suppressed by adding peritoneal exudate cells from old mice. Flow cytometry analysis revealed that the proportion of MAC-1+ cells with a high density of type II or type III receptor for the Fc portion of IgG (Fc gamma RII/IIIbright cells) was increased markedly in the periotoneal exudate cells from old mice. The prominent suppressor activity for Con A responses of control spleen cells was found in the Fc gamma RII/IIIbright cells, whereas MAC-1+ cells with a low density of Fc gamma RII/III (Fc gamma RII/IIIdull cells) did not suppress the Con A responses. On the other hand, both the basal corticosterone concentrations in serum and the mRNA expression for GC receptor in peritoneal exudate cells increased significantly in old mice. Furthermore, the proportion of Fc gamma RII/IIIbright cells in peritoneal exudate cells from old mice was normalized on administration of the GC antagonist RU 38,486 (mifepristone). These results suggest that the increase in basal corticosterone concentrations in old mice induces the generation of Fc gamma RII/IIIbright suppressor cells, possibly leading to the immune-suppressive state.

Aging↗
PubMed1998

Mapping of cholecystokinin transcription in transgenic mouse brain using Escherichia coli beta-galactosidase reporter gene.

Cholecystokinin (CCK), a neuro-gut peptide, occurs not only in the nervous but also in the digestive system. As a first step in elucidating whether CCK gene expression and its physiological functions co-operate in these separate organs, transgenic mice were produced using CCK promoter that directs bacterial beta-galactosidase as a reporter gene. A new transgenic vector was constructed, inserting the SV40 poly A signal 5' to the CCK promoter to impede any transcription upstream of the transgene. A 2.4 kb.p. region upstream to the transcription start site of the mouse CCK gene was used as the promoter. Transgene expression was detected first at embryonic 13.5 days in the central nervous system and increased after birth. The distribution of cells expressing beta-galactosidase transgene agreed fairly well with that of in situ hybridization. In addition, the upregulation of CCK gene expression was clearly demonstrated by expressing beta-galactosidase after injury to the brain. These results indicated that the 2.4 kb.p. of the CCK gene promoter region was sufficient to direct appropriate tissue-specific gene expression in mice.

Animals↗
PubMed1998

Inhibition of depolarization-induced nitric oxide synthase activation by NS-7, a phenylpyrimidine derivative, in primary neuronal culture.

Neuronal nitric oxide synthase (NOS) is considered to be involved in the pathogenesis of ischemic brain damage. In the present study, the effect of a novel neuroprotective phenylpyrimidine derivative, 4-(4-fluorophenyl)-2-methyl-6-(5-piperidinopentyloxy)pyrimidine hydrochloride (NS-7), on depolarization-stimulated NOS activity was examined in cultured neurons of mouse cerebral cortex. Various depolarizing stimuli such as veratridine, KCl, and N-methyl-D-aspartate increased the NOS activity determined by cyclic GMP formation. NS-7 concentration-dependently inhibited both the veratridine- and KCl-induced NOS activation with IC50 values of 9.3 and 9.6 microM, respectively. The reversal of KCl-evoked NOS activity by NS-7 was also observed under blockade of both ionotropic glutamate receptors and the Na+ channel with MK-801, 6-cyano-7-nitroquinoxaline-2,3-dione, and tetrodotoxin. In contrast, NS-7, even at 100 microM, did not affect N-methyl-D-aspartate-stimulated NOS activity, nor did it have any influence on NOS activity determined in the soluble fraction of rat hippocampus. Because NS-7 has already been shown to block both Na+ and Ca2+ channels, the present findings suggest that this compound inhibits depolarization-induced NOS activation by reducing Ca2+ influx through blockade of Na+ and Ca2+ channels in primary neuronal culture.

Animals↗
PubMed1998

Development of a huge varix following endovascular embolization for cerebellar arteriovenous malformation. A case report.

We report on the case of a huge varix that developed after the endovascular embolization of a cerebellar arteriovenous malformation (AVM) with a single drainer. A 21-year-old male presented with trigeminal neuralgia which was caused by the dilated drainer of the AVM. A varix was found at the basal vein of Rosenthal 2 months after an initial stage of embolization with polyvinyl alcohol particles; it diminished after the surgical extirpation of the AVM. The varix formation might have been facilitated by the stenosis in the vein of Galen and by the dynamic changes that followed the embolization. This rare complication should be kept in mind when embolization is performed for AVMs with impaired venous outlets.

Adult↗
PubMed1998

Dynamics of hepatitis C viremia following interferon-alpha administration.

Knowledge of the dynamics of hepatitis C virus (HCV) in vivo is important for elucidation of its pathogenesis and the establishment of therapeutic guidelines. The aim of this study was to obtain kinetic information about virus load following interferon-alpha (IFN-alpha) administration. Serial serum HCV core protein and HCV RNA levels were measured. IFN-alpha exponentially reduced serum HCV levels. The mean (+/-SD) viral half-life was 7.0 +/- 2.6 h in HCV core protein assay and 7.2 +/- 3.1 h in HCV RNA assay on the first day of therapy. This initial rapid decrease was followed by a slower decrease in serum HCV levels thereafter. Thus, the biphasic reduction in virus load during IFN-alpha therapy was demonstrated.

Adult↗
PubMed1998

Isolation and characterization of a cDNA clone of UDP-galactose: flavonoid 3-O-galactosyltransferase (UF3GaT) expressed in Vigna mungo seedlings.

Four cDNA clones were isolated from Vigna mungo seedlings by the screening with cDNA encoding UDP-glucose:flavonoid 3-O-glucosyltransferase (UF3GT) of Antirrhinum majus as a probe; the product of the gene corresponding to one cDNA was more highly expressed in the first simple leaves than in stems. Nucleotide sequence analysis revealed 1,691 bp (including 326 bp non-reading) containing an open reading frame of 455 amino acids. The deduced amino acid sequence showed 42% and 23% identity with those of A. majus UDP-glucose:flavonoid 3-O-glucosyltransferase (UF3GT) and Petunia hybrida UDP-rhamnose:anthocyanidin 3-O-glucoside rhamnosyltransferase (RT), respectively. One region of the cDNA (amino acids 325 to 387) showed similarity to ceramide UDP-galactosyltransferases of mice, rats and humans. A crude extract from Escherichia coli, in which the protein was expressed from the cDNA, showed high UF3GaT activity but low UF3GT activity, and was similar in K(m), optimal pH and substrate specificity to UF3GaT from V. mungo. We conclude that we have obtained UDP-galactose:flavonoid 3-O-galactosyltransferase (UF3GaT) cDNA from V. mungo.

Amino Acid Sequence↗
PubMed1998

Decrease in donor site erythema by application of hyperthermia.

To reduce the erythematous discoloration of donor sites used for split-thickness skin grafts, we applied mild topical hyperthermia to the donor sites in 10 patients. Disposable chemical pocket warmers served as the source of heat and were kept in place for 8 hours daily for 8 weeks. Untreated controls consisted of the application of "used" warmers to another part of the lesion. Results were graded subjectively by physicians and patients as effective or ineffective. Quantitative evaluation of the change in the redness of the donor site was used as a system for color analysis. Changes in blood flow were evaluated with the laser Doppler flowmeter, and were evaluated after the application of heat for 8 weeks. Lessening of the erythema and a decrease in blood flow were observed in the affected areas of all subjects. There were no adverse effects.

Adult↗
PubMed1998

Brain SPECT imaging using three different tracers in subacute cerebral infarction.

Two patients with subacute cerebral infarction underwent benzodiazepine receptor imaging using I-123-iomazenil and cerebral perfusion imaging with Tc-99m HMPAO and Tc-99m ECD. Iomazenil early images resembled HMPAO images, which demonstrated increased uptake in a part of the infarcted site. Iomazenil delayed images and ECD images showed reduced accumulation in the same area. Crossed cerebellar diaschisis was observed in HMPAO, ECD, and iomazenil early images, but it was not remarkable in iomazenil delayed images. These cases suggest that sequential iomazenil images visualized increased uptake with relatively impaired viability in the infarcted site and hypoperfusion with preserved viability in the contralateral cerebellar hemisphere, which could not be recognized without using both HMPAO and ECD in the subacute phase of cerebral infarction.

Adult↗
PubMed1998

Detection of verotoxin-producing Escherichia coli O157:H7 by multiplex polymerase chain reaction.

We constructed primers for multiplex polymerase chain reaction (PCR) to detect verotoxin-producing Escherichia coli (VTEC) O157:H7. The multiplex PCR primers were designed from the sequence of the flagellin structural gene of Escherichia coli flagellar type H7 (GenBank under accession number L07388), and from the sequence of the rfbE gene of Escherichia coli O157:H7 (GenBank under accession number S83460). In addition to these primers, we used a primer pair reported by Karch and Meyer (J. Clin. Microbiol. 27: 2751-2757, 1989) to amplify various VT genes from VTEC. All of the examined specimens (18 isolates) of VT-producing E. coli O157:H7 showed a positive result by the multiplex PCR test with the three sets of primers. The sensitivity of detection for VT-producing E. coli O157:H7 was shown to be at least 3,000 cells per PCR tube.

Animals↗