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T Ikeda

Publications and source records attributed to T Ikeda.

At least 397 records · Page 22Linked to original sources
PubMed1999

Comparison of the effect-site k(eO)s of propofol for blood pressure and EEG bispectral index in elderly and younger patients.

BACKGROUND: Drug effect lags behind the blood concentration. The goal of this investigation was to determine the time course of plasma concentration and the effects of propofol demonstrated by electroencephalogram or blood pressure changes and to compare them between elderly and young or middle-aged patients. METHODS: A target-controlled infusion was used to rapidly attain and maintain four sequentially increasing, randomly selected plasma propofol concentrations from 1 to 12 microg/ml in 41 patients aged 20-85 yr. The target concentration was maintained for about 30 min. Bispectral index (BIS), spectral edge frequency, and systolic blood pressure (SBP) were used as measures of propofol effect. Because the time courses of these measures following the started drug infusion showed an exponential pattern, the first-order rate constant for equilibration of the effect site with the plasma concentration (k(eO)) was estimated by fitting a monoexponential model to the effect versus time data resulting from the pseudo-steady-state propofol plasma concentration profile. RESULTS: The half-times for the plasma-effect-site equilibration for BIS were 2.31, 2.30, 2.29, and 2.37 min in patients aged 20-39, 40-59, 60-69, and 70-85 yr, respectively (n = 10 or 11 each). The half-times for SBP were 5.68, 5.92, 8.87, and 10.22 min in the respective age groups. All were significantly longer than for BIS (P < 0.05). The propofol concentration at half of the maximal decrease of SBP was significantly greater (P < 0.05) in the elderly than in the younger patients. CONCLUSIONS: The effect of propofol on BIS occurs more rapidly than its effect on SBP. Age has no effect on the rate of BIS reduction with increasing propofol concentration, whereas with increasing age, SBP decreases to a greater degree but more slowly.

Adult↗
PubMed1999

High salt intake potentiates the renal vascular and glomerular damage caused by low doses of angiotensin II in uni-nephrectomized rats.

OBJECTIVE: We recently reported that the renin-angiotensin system plays an important role in the progression of vascular and kidney injuries, even in Dahl salt-sensitive rats with volume-dependent hypertension. In this study, we investigated whether a high-salt diet increases susceptibility to kidney injury induced by angiotensin II in normotensive, uni-nephrectomized Sprague-Dawley rats, which mimics the condition of salt-volume repletion and blunted renin-angiotensin system. METHODS: The rats were fed either a low-salt (0.3% NaCl) or a high-salt (4% NaCl) diet and divided into five groups: two control groups with a low-salt or a high-salt diet without angiotensin II infusion (saline infusion), and three angiotensin II groups (angiotensin II infusion, 10 or 50 ng/kg per min with high-salt diet, 50 ng/kg per min with low-salt diet, subcutaneously). The rats were kept on these regimes for 8 weeks. The blood pressure was measured every week. Functional and morphological alterations in the kidney were assessed at the end of the experiment RESULTS: There were no differences in the arterial blood pressures of the five experimental groups. However, angiotensin II infusion increased the weights of the heart and aortic walls in a dose-dependent manner in the high-salt groups. There was also a dose-dependent increase in proteinuria, N-acetyl-beta-D-glucosaminidase activity (NAG) excretion, and additional glomerular and arterial injuries in the kidney, associated with angiotensin II infusion in the high-salt groups. In the rats given a higher dose of angiotensin II, the high-salt diet significantly increased the weights of the heart and aortic walls and exacerbated the renal function and morphological injuries, compared to the low-salt group. High-salt diet alone increased the kidney and heart weights. However, it did not significantly influence the results of the morphological and functional study. On the other hand, angiotensin II infusion on a low-salt diet showed a trend towards glomerular damage; however, the effects were small and not significant. Similarly, there were few effects of angiotensin II infusion on morphology and functional study on a low-salt diet CONCLUSION: These data clearly show that a high-salt intake increases susceptibility of the kidney to injuries induced by low doses of angiotensin II in normotensive, uni-nephrectomized rats.

Angiotensin II↗
PubMed1999

Cryptobacterium curtum gen. nov., sp. nov., a new genus of gram-positive anaerobic rod isolated from human oral cavities.

Novel Eubacterium-like isolates, strains 12-3T and KV43-B, which were isolated from the periodontal pocket of an adult patient with periodontal disease and necrotic dental pulp, respectively, were studied taxonomically and phylogenetically. The morphological and differential biochemical characteristics of these organisms are also described in this paper. These organisms were Gram-positive, anaerobic, non-spore-forming, rod-shaped bacteria that were inert in most of the conventional biochemical tests and closely resembled members of asaccharolytic oral Eubacterium species. On the other hand, protein profiles of whole cells in SDS-PAGE and Western immunoblotting reaction analysis distinguished these isolates from strains of the previously described genus Eubacterium. The G+C content of the DNAs from the novel isolates was 50 and 51 mol%, respectively. The levels of DNA-DNA relatedness to other asaccharolytic oral Eubacterium species, including Eubacterium brachy, Eubacterium lentum, Eubacterium nodatum, Eubacterium timidum, Eubacterium saphenum, Eubacterium minutum and Eubacterium exiguum, was less than 11%. These organisms also exhibited a very low level of reassociation with the DNA of Eubacterium limosum, the type species of the genus Eubacterium. The results of 16S rDNA sequence comparisons revealed that these organisms represent a novel lineage distinct from all previously described genera of Gram-positive, rod-shaped bacteria. On the basis of our results, it is suggested that strains 12-3T and KV43-B should be classified in a new genus and species, for which the name Cryptobacterium curtum gen. nov., sp. nov. is proposed. The type strain of Cryptobacterium curtum is 12-3T (= ATCC 700683T).

Adult↗
PubMed1999

Molecular epidemiological study of a mass outbreak caused by enteropathogenic Escherichia coli O157:H45.

We made a molecular analysis of O157:H45 Escherichia coli isolated from a mass outbreak that occurred in Obihiro City. Using DNA analysis, we confirmed this infection case as a mass outbreak. Although the isolates expressed O157 antigen, they did not produce Vero toxin. We concluded they were enteropathogenic E. coli (EPEC) because they had a bfp gene and an EAF plasmid, and further they exhibited local adherence to HEp-2 cells. We believe this is the first report of a mass outbreak by O157 EPEC, and we suggest that PCR using eae- and bfp-specific primers and HEp-2 adherence assay are useful to identify EPEC.

Disease Outbreaks↗
PubMed1999

Gd-DTPA enhancement of cranial nerves on MR imaging. Neoplastic lesions.

This study describes a radiological finding - enhancement of cranial nerves and correlates patients' clinical findings and outcome. Seven patients with enhancement of cranial nerves on postcontrast MR were retrospectively reviewed. Cranial nerves having contrast enhancement were optic, oculomotor, trigeminal, facial, acoustic, glossopharyngeal, vagus and accessory nerves. The patients' underlying diseases were malignant lymphoma (3), leukemia (1 patient) and metastatic tumor (2 lung, 1 rectum cancer). Most of the cases (4 out of 7) developed parenchymatous lesion later. Seven patients had CSF cytology study, positive in 3 cases, negative in 4 cases at first spinal tap. In 1 case (case 5) of negative cytology, elevated CEA (carcinogen antibody) was noted. In 2 cases, initial symptoms were sudden hearing loss. Autopsy was done for 1 case of metastatic tumor involving cranial nerves. Contrast MR is a useful examination for depicting cranial nerve involvement with neoplastic change.

Adult↗
PubMed1999

The effect of subcutaneous tetrathiomolybdate administration on copper and iron metabolism, including their regional redistribution in the brain, in the Long-Evans Cinnamon rat, a bona fide animal model for Wilson's disease.

The present work was performed to examine the effect of tetrathiomolybdate on Cu and Fe metabolism, especially redistribution of Cu and Fe in the brains of Long-Evans Cinnamon rats, with inherently abnormal Cu deposition in the liver. The drug was injected subcutaneously at 5 mg/kg of body weight twice a week for 65 days (total dose of 20 mg) into 40-day-old Long-Evans Cinnamon rats. In Long-Evans Cinnamon rats treated with tetrathiomolybdate, the hepatic Cu concentration was 60 microg/g wet weight, compared to 170 microg/g in untreated rats. In seven brain regions (cerebellum, medulla oblongata, hypothalamus, striatum, midbrain, hippocampus and cortex) of the Long-Evans Cinnamon rats treated with tetrathiomolybdate. the Cu concentration (1.5 to 2.3 microg/g) was slightly lower (1.6 to 2.7 microg/g) than in untreated rats. A significant difference between the two groups was found only in the midbrain. Brain Fe concentrations in regions other than the striatum were not changed significantly by the tetrathiomolybdate injections. The hepatic Fe concentration was about 120 microg/g in Long-Evans Cinnamon rats without tetrathiomolybdate. Tetrathiomolybdate injection further increased the concentration to about 250 microg/g. Our results indicated that subcutaneous tetrathiomolybdate injection did not have an effect that stimulated redistribution of Cu and Fe in the seven brain regions examined, although hepatic Cu was markedly decreased and the removed Cu was deposited in kidneys, spleen and testes. The increased hepatic Fe level should be taken into account when considering side effects of the compound.

Animals↗
PubMed1999

A one-dimensional unsteady separable and reattachable flow model for collapsible tube-flow analysis.

Taking into account both flow separation and reattachment observed in available experimental results on flows in a quasi-two-dimensional channel, we present a one-dimensional unsteady flow model, which is applicable to a flow in a collapsible tube. The flow model has been derived from the two-dimensional Navier-Stokes equations by introducing the concept of a dividing streamline, which divides a separated flow into a jet and a dead-water zone. We also present a criterion for the determination of a separation point. Numerical results show that the locations of the predicted separation points agree well with the experimental data. The predicted static pressure of the separated flow is almost constant downstream of the separation point and increases quickly just before the reattachment point as observed in the experiment. Finally, using the present flow model and the separation criterion, we examine the oscillatory behavior of an unsteady flow in a symmetric channel whose walls move sinusoidally.

Compliance↗
PubMed1999

[The incidences of virulence genes in Escherichia coli strains from sporadic diarrheal children].

To investigate the incidence of diarrheagenic Escherichia coli among E. coli strains screened by commercially available O-antigen antisera, we used PCR to isolate 8 virulence genes (eae, bfpA, IpaH, LT, ST, VT1, VT2, and aggR) in 184 E. coli strains sampled from sporadic diarrheal children in our district. eae and bfpA are the localized adherence factor genes of enteropathogenic E. coli (EPEC). IpaH is the invasion antigen gene of enteroinvasive E. coli (EIEC), LT and ST are the toxin genes of enterotoxigenic E. coli (ETEC), VT1 and VT2 are the toxin genes of enterohemorrhagic E. coli (EHEC), and aggR is the adherence factor gene of enteroaggregative E. coli (EAggEC). The results were as follows: eae, 7 (3.8%); bfpA, 0 (0%); IpaH, 0 (0%); LT, 0 (0%); ST, 2 (1.1%); VT, 5 (2.7%); aggR, 8 (4.3%). Seven isolates with eae did not have bfpA, and did not show a localized adherence to HeLa cells. Seven of the 8 isolates with aggR showed aggregative adherence to HeLa cells, while their O-serotypes of them were O111:H21 or O111:HUT. Because of the low incidence of the virulence gene, the commercially available O-antigen antisera was not expected to be useful for the screening of diarrheagenic E. coli, except for EHEC and EAggEC. EAggEC may be important as a pathogen of sporadic diarrhea of children as well as EHEC.

Child↗
PubMed1999

Isolation and characterization of two cryptic plasmids in the ammonia-oxidizing bacterium Nitrosomonas sp. strain ENI-11.

Two plasmids were discovered in the ammonia-oxidizing bacterium Nitrosomonas sp. strain ENI-11, which was isolated from activated sludge. The plasmids, designated pAYS and pAYL, were relatively small, being approximately 1.9 kb long. They were cryptic plasmids, having no detectable plasmid-linked antibiotic resistance or heavy metal resistance markers. The complete nucleotide sequences of pAYS and pAYL were determined, and their physical maps were constructed. There existed two major open reading frames, ORF1 in pAYS and ORF2 in pAYL, each of which was more than 500 bp long. The predicted product of ORF2 was 28% identical to part of the replication protein of a Bacillus plasmid, pBAA1. However, no significant similarity to any known protein sequences was detected with the predicted product of ORF1. pAYS and pAYL had a highly homologous region, designated HHR, of 262 bp. The overall identity was 98% between the two nucleotide sequences. Interestingly, HHR-homologous sequences were also detected in the genomes of ENI-11 and the plasmidless strain Nitrosomonas europaea IFO14298. Deletion analysis of pAYS and pAYL indicated that HHR, together with either ORF1 or ORF2, was essential for plasmid maintenance in ENI-11. To our knowledge, pAYS and pAYL are the first plasmids found in the ammonia-oxidizing autotrophic bacteria.

Amino Acid Sequence↗
PubMed1999

Direct and rapid detection by PCR of Erysipelothrix sp. DNAs prepared from bacterial strains and animal tissues.

A PCR method for rapid screening of Erysipelothrix spp. in the slaughterhouse was carried out by using four species-specific sets of oligonucleotide primers after initial amplification with the primer set MO101-MO102, which amplifies the 16S rRNA sequences of all four Erysipelothrix species. The DNA sequences coding for the rRNA gene cluster, including 16S rRNA, 23S rRNA, and the noncoding region downstream of 5S rRNA, were determined in order to design primers for the species-specific PCR detection system. The homology among the 4.5-kb DNA sequences of the rRNA genes of Erysipelothrix rhusiopathiae serovar 2 (DNA Data Bank of Japan accession no. AB019247), E. tonsillarum serovar 7 (accession no. AB019248), E. rhusiopathiae serovar 13 (accession no. AB019249), and E. rhusiopathiae serovar 18 (accession no. AB019250) ranged from 96.0 to 98.4%. The PCR amplifications were specific and were able to distinguish the DNAs from each of the four Erysipelothrix species. The results of PCR tests performed directly with tissue specimens from diseased animals were compared with the results of cultivation tests, and the PCR tests were completed within 5 h. The test with this species-specific system based on PCR amplification with the DNA sequences coding for the rRNA gene cluster was an accurate, easy-to-read screening method for rapid diagnosis of Erysipelothrix sp. infection in the slaughterhouse.

Abattoirs↗
PubMed1999

Vitrectomy for cystoid macular oedema with attached posterior hyaloid membrane in patients with diabetes.

AIM: To report the success of vitrectomy in eliminating cystoid macular oedema and improving vision in three eyes of two patients with diabetic cystoid macular oedema. In all of the eyes there was no ophthalmoscopic evidence of traction from a posterior hyaloid membrane or from proliferative tissue. METHODS: Pars plana vitrectomy was performed on three eyes of two patients with diabetic cystoid macular oedema who did not show traction upon examination with a slit lamp biomicroscope and a scanning laser ophthalmoscope. RESULTS: Cystoid changes disappeared 1, 3, and 5 days, postoperatively, and diffuse macular oedema resolved within 2 weeks. The visual acuity was improved and maintained. CONCLUSION: Vitrectomy can be effective in some patients with diabetic cystoid macular oedema even in patients who lack evidence of traction by ophthalmoscopy.

Adult↗
PubMed1999

Alterations of muscarinic acetylcholine receptor subtypes in diffuse lewy body disease: relation to Alzheimer's disease.

OBJECTIVES: Dementia associated with Lewy bodies in cortical and subcortical areas is classified as dementia of the non-Alzheimer type and termed diffuse Lewy body disease (DLBD). The generic term "dementia with Lewy bodies (DLB)" was proposed in the international workshop on Lewy body dementia to include the similar disorders presenting Lewy bodies. In DLB, a lower level of choline acetyltransferase (ChAT) activity in the neocortex was found compared with that in Alzheimer's disease. The purpose of the present study was to determine the total amount of muscarinic acetylcholine receptors (mAChRs) and relative proportion of each subtype (m1-m4) of mAChRs in the frontal and temporal cortex of seven DLBD and 11 Alzheimer's disease necropsied brains. METHODS: A [(3)H]quinuclidinyl benzilate (QNB) binding assay and an immunoprecipitation assay using subtype-specific antibodies were performed. Each antibody was raised against fusion proteins containing peptides corresponding to the third intracellular (i3) loops of the respective mAChR subtype. RESULTS: The total amounts of mAChRs were significantly lower in the preparations of temporal cortices from DLBD and Alzheimer's disease than in those from dead controls (seven cases). In both diseases, the proportion of the m3 receptor in the frontal cortex was significantly increased and that of the m4 receptor in the temporal cortex was significantly decreased compared with the control specimens. The proportions of the m1 and m2 subtypes were significantly different in the temporal cortex. The proportion of the m1 receptor was significantly greater in the DLBD brains, whereas that of the m2 receptor was significantly greater in the Alzheimer's disease brains than in the controls. CONCLUSIONS: The m1 receptor is the major subtype in the cerebral cortex, and m2 is known to be present at presynaptic terminals. The higher proportions of m1 in DLBD and m2 in Alzheimer's disease suggest that the manner of degeneration in the cholinergic system is different between the diseases. It is hypothesised that a severe depletion of presynaptic cholinergic projective neurons causes the upregulation of m1 receptor in the temporal cortex in DLBD.

Aged↗
PubMed1999

Expression of C-type natriuretic peptide during development of rat lung.

C-type natriuretic peptide (CNP), recently found to be secreted from vascular endothelial cells, is now viewed as a novel endothelium-derived relaxing peptide. However, the distribution and expression of CNP during cardiopulmonary development is unclear. To follow changes in the expression of CNP during lung development, we examined rat embryos and neonates using Northern blot analysis and in situ hybridization for CNP mRNA and radioimmunoassay and immunohistochemistry for CNP protein. A substantial expression of CNP mRNA was first detected on postnatal day 2, and it thereafter remained fairly steady. The level of CNP protein also increased rapidly after postnatal day 1, reaching a settled level on postnatal day 4. CNP protein and mRNA were detected in the endothelium and smooth muscle cells of blood vessels and in bronchial airway and alveolar epithelia. Immunoreactivity for CNP protein in the endothelium of blood vessels increased to an intense level after the saccular stage. These results suggest that the changes in CNP levels may be related to the occurrence of pulmonary vasodilation after birth.

Animals↗
PubMed1999

Ruptured arteriovenous malformation in a boy with Beckwith-Wiedemann syndrome.

We report here the first case of ruptured arteriovenous malformation (AVM) in a patient with Beckwith-Wiedemann syndrome (BWS). The subject was a 9-year-old boy exhibiting various abnormal features characteristic of BWS, who had undergone frequent surgical management for conditions such as umbilical hernia, polydactyly, inguinal hernia, cleft palate and lip, and undescended testis. The patient was suffering from ruptured AVM in the right frontal lobe, which was successfully managed with surgical interventions. The possible genetic mechanisms that formed the cerebral vascular malformations in this patient are discussed.

Aneurysm, Ruptured↗
PubMed1999

Sulfonylureas stimulate renin secretion from the perfused kidney of the rat.

To elucidate whether sulfonylureas directly influence renin secretion, the effect of tolbutamide, glibenclamide, or chlorpropamide on renin secretion was investigated by using the perfused kidney of the rat. The isolated kidneys of male Wistar rats (200-250 g) were perfused with a medium containing 2 microM tolbutamide, 2 microM glibenclamide, and 2 microM chlorpropamide, respectively. Renin activity significantly increased from a basal value of 11.7 +/- 3.6 to a peak value of 20.6 +/- 5.5 ng/Ang I/ml/h with tolbutamide, from 14.4 +/- 4.6 to 32.7 +/- 6.5 ng/Ang I/ml/h with glibenclamide, and from 15.0 +/- 4.9 to 30.4 +/- 6.1 ng/Ang I/ml/h with chlorpropamide. The cAMP concentration in the effluent was not changed by the addition of the sulfonylureas. In kidneys perfused with a calcium-free medium, glibenclamide produced a significant increase in renin activity from a basal value of 13.4 +/- 2.1 to a peak value of 30.6 +/- 3.4 ng Ang I/ml/h. These results suggest that sulfonylureas stimulate renin secretion from perfused rat kidneys.

Animals↗
PubMed1999

Long-term inhibition of renin-angiotensin system sustains memory function in aged Dahl rats.

The Dahl salt-sensitive (DS) rat, a genetic model of salt-induced hypertension in humans, is more likely to develop severe vascular injuries than a rat with spontaneous hypertension. We designed an experiment to scrutinize the effects of renin-angiotensin inhibition on cognitive dysfunction in the aged, normotensive DS with a passive avoidance test. Eighteen months of treatment with a very low dose of the angiotensin-converting enzyme (ACE) inhibitor cilazapril (2.5 microg/mL in drinking water) or the angiotensin II type 1 receptor antagonist E4177 did not reduce blood pressure throughout the experiment, although in the low dose cilazapril group (12.5 microg/mL in drinking water), blood pressure dropped within 6 months after treatment began. The cilazapril treatments dose-dependently improved memory function in the aged, normotensive DS fed a low-salt diet compared with the untreated, control rats. This improvement was associated with significant increases in hippocampal CA1 cells and capillary densities in the CA1 regions compared with those in the untreated DS. Similarly, E4177 slightly improved the memory dysfunction observed in the aged DS. The cells in the hippocampal CA1 region were restored slightly, but the capillary densities were not influenced by the receptor antagonist. On the other hand, the ACE inhibitor and receptor antagonist both attenuated urinary protein excretions with an improvement of glomerular sclerosis. These data suggest that long-term treatment with an ACE inhibitor improves memory dysfunction probably through restoration of capillary and hippocampal cells. The effects are due to the inhibition of the angiotensin II type 1 receptor and probably to the enhancement of the kallikrein-kinin system.

Aging↗
PubMed1999

Pathophysiological roles of endothelin-1 in Dahl salt-sensitive hypertension.

The purpose of the present experiment was to study the pathophysiological roles of endothelin-1 (ET-1) in salt-sensitive hypertension with the use of Dahl salt-sensitive (DS) and salt-resistant (DR) rats. PreproET-1 mRNA expression was determined by reverse transcription-polymerase chain reaction. In the kidney, expression of preproET-1 mRNA was greater in DS rats on a normal salt diet compared with DR rats of the same age. In DS rats, the level of preproET-1 mRNA expression in kidney had a significant correlation with systolic blood pressure. The expression of preproET-1 mRNA in aorta and kidney was increased by 3-week high salt intake in DS rats but not in DR rats. Expression of preproET-1 mRNA and ET-1 levels in left ventricle was exaggerated by high salt intake in DS rats. However, there was no significant difference in plasma ET-1 levels between DS and DR rats regardless of salt intake. Pressor response curves for ET-1 in DS rats with or without high salt intake were significantly shifted to the left compared with those in DR rats. A single oral dose (3 to 10 mg/kg) of J-104132 (L-753 037), a potent, orally active mixed endothelin A and B (ET(A)/ET(B)) receptor antagonist, reduced blood pressure to normotensive levels in DS rats with high salt intake, and its action was maintained for >/=24 hours. In DS rats with normal salt intake, J-104132 (10 mg/kg) slightly but significantly decreased blood pressure. DR rats did not show obvious depressor responses to J-104132 (10 mg/kg) regardless of salt intake. These results suggest that ET-1 acts as one of the pathophysiological factors in the development and maintenance of salt-sensitive hypertension, and a mixed ET(A)/ET(B) receptor antagonist could be useful in the treatment for salt-sensitive hypertension.

Animals↗