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H Nagashima

Publications and source records attributed to H Nagashima.

At least 73 records · Page 4Linked to original sources
PubMed2000

MAGE-specific cytotoxic T lymphocytes require non-specific CD54 adherence receptors on carcinoma cells.

We investigated several factors that could regulate the susceptibility of carcinoma cells to MAGE-2-specific CTL mediated lysis. Cytofluorometric analysis showed that the cytolysis correlated with the expression of CD54. IFN-gamma treatment induced the TAP-1 and LMP-2 genes, continuously up-regulated the HLA class I expression and increased cytolysis. Although HLA class I were highly induced in MRKnu1 cells, CD54 was not induced and the cytolysis was minimal. Cytotolysis of IFN-gamma-treated MKN-1 cells was completely inhibited by a monoclonal anti-CD54 antibody. These results suggest that HLA-restricted CTL lysis requires non-specific CD54 adherence receptors in addition to specific TCR signals.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

[Diagnostic usefulness of KL-6 measurements in patients with pulmonary complications after administration of amiodarone].

Amiodarone-induced pulmonary toxicity is one of the major complications in patients receiving administration of amiodarone. KL-6 is a useful indicator to evaluate the activity of interstitial pneumonitis. We studied the clinical utility of KL-6 as a marker for amiodarone-induced pulmonary toxicity. We investigated 6 patients in whom chest radiography revealed abnormal consolidations after administration of amiodarone from 1997 to 1999. All patients were male aged 56 to 76 years (mean 66 +/- 7 years). The indications for amiodarone included sustained ventricular tachycardia in 5 patients and atrial fibrillation in one patient with refractory heart failure. The mean left ventricular ejection fraction was 31 +/- 12% (22-52%). KL-6 levels were measured by a sandwich type enzyme immunoassay using a murine monoclonal antibody (KL-6 antibody), and the cutoff level was determined at 520 U/ml. Complications occurred from 17 days to 45 months after treatment with amiodarone. The KL-6 levels were abnormally high (2,100 and 3,000 U/ml) in 2 patients with amiodarone-induced pneumonitis but under the cutoff level in the non-pneumonitis patients. In one patient with amiodarone-induced pneumonitis, the KL-6 level increased from 695 to 2,100 U/ml concurrently with worsening interstitial changes shown by high resolution computed tomography. We conclude that KL-6 has practical uses as a marker for the detection and evaluation of amiodarone-induced pulmonary toxicity.

Aged↗
PubMed2000

Malfunction of a Hancock bioprosthesis in the mitral position 24 years after initial implantation.

BACKGROUND AND AIMS OF THE STUDY: Although many types of cardiac bioprosthetic valves are currently available, the major disadvantage of their use is limited durability due to progressive structural valve deterioration. Few such valves function beyond 20 years. METHODS: A 61-year-old man was admitted urgently to our institute with acute mitral insufficiency, 24 years after undergoing mitral valve replacement with a 25-mm standard Hancock porcine bioprosthesis for mitral stenosis. RESULTS: Mitral valve reoperation was performed successfully with a mechanical valve. The explanted bioprosthesis showed leaflet perforations and a commissural tear, moderate calcification on the commissures, and pannus overgrowth. CONCLUSION: The findings in this case suggest that individual patient variables, as well as the design and the construction of the valve are major determining factors in the rate of valve failure.

Bioprosthesis↗
PubMed2000

[Influences of chronic stress on central nervous systems].

Chronic mild or moderate stress elicits an adaptive change in central nervous systems that function to maintain homeostasis. The principal components of stress response are the extrahypothalamic corticotropin-releasing hormone (CRH) and the locus coeruleus (LC)-norepinephrine (NE) systems. CRH is known to produce various stress-, anxiety- and arousal-associated behaviors in animals. Moreover, CRH causes an increase in the firing rate and activity of tyrosine hydroxylase in the LC, and NE release in LC projection areas. It is thought that chronic inescapable and unpredictable stress can result in a sustained dysregulation of both CRH neuronal activity and LC-NE systems. One may hypothesize that the NE-CRH interaction occurs in the terminal projection of forebrain NE systems, the hypothalamic paraventricular nucleus (PVN), the bed nucleus of the stria terminalis (BNST) and the central nucleus of the amygdala (CeA) where NE stimulates CRH release. Such CRH-NE-CRH feed-forward systems elicit progressive augmentation of stress responsivity with repeated exposure. The beta-adrenergic receptor down-regulation is induced by acute and chronic exposure to moderate and predictable stress, implying an adaptation to stress. However, chronic unpredictable (variable) stress (CVS), a model for depression, up-regulated the beta-AR. In our laboratory, we found that concurrent treatment with the selective serotonin reuptake inhibitor (SSRI) citalopram caused beta-R down-regulation in the frontal cortex of rats treated with CVS for 14 days. As previously reported by the authors, an increase in 5-HT availability plays a role in preserving beta-R down-regulation by NE potentiating agents. In depressed patients, hyperactivation of the CRH-NE systems caused by the CRH-NE feed-forward system is thought to be involved in generating anxiety, sympathetic activation and hyperarousal. Moreover, a decrease in the 5-HT turnover in depressed patients has been reported. Accordingly, it is proposed that an increase in 5-HT availability by SSRI might contribute to normalize beta-R down-regulation as an adaptive regulatory mechanism against excessive CRH-NE neurotransmission under a "stressful" situation.

Animals↗
PubMed1999

Determination of inorganic anions by ion chromatography using a graphitized carbon column dynamically coated with cetyltrimethylammonium ions.

The simultaneous determination of inorganic anions by ion chromatography using a dynamically coated graphitized carbon column with cetyltrimethylammonium (CTA) ions was investigated with suppressed conductivity detection. Column preparations with CTA and sodium carbonate-sodium hydrogencarbonate concentration in the eluent were examined to optimize the separation of seven common anions (F-, Cl-, NO2-, Br-, NO3-, HPO(4)2- and SO(4)2-). Calibration curves were linear from 0.5 to 5 micrograms/ml for F-, from 1.0 to 10 micrograms/ml for Cl-, from 1.5 to 15 micrograms/ml for NO2-, from 2.0 to 20 micrograms/ml for Br- and NO3-, from 5.0 to 50 micrograms/ml for HPO(4)2- and from 3.0 to 30 micrograms/ml for SO(4)2- with correlation coefficients (r) of 0.999 or better. The relative standard deviations of peak areas were between 0.3 and 0.9% for 10 repeated measurements. The application of this newly developed method was demonstrated by the determination of inorganic anions in the water for pharmaceutical purposes. Using CTA-Br as the coating agent, a permanently coated ion-exchange column was obtained, which allowed efficient separations of seven anions without adding any coating agent to the eluent.

Anions↗
PubMed1999

Novel mechanism associated with an inherited cardiac arrhythmia: defective protein trafficking by the mutant HERG (G601S) potassium channel.

BACKGROUND: The congenital long-QT syndrome (LQTS) is an inherited disorder characterized by a prolonged cardiac action potential and a QT interval that leads to arrhythmia. Mutations in the human ether-a-go-go-related gene (HERG), which encodes the rapidly activating component of the delayed rectifier current (IKr), cause chromosome 7-linked LQTS (LQT2). Studies of mutant HERG channels in heterologous systems indicate that the mechanisms mediating LQT2 are varied and include mutant subunits that form channels with altered kinetic properties or nonfunctional mutant subunits. We recently reported a novel missense mutation of HERG (G601S) in an LQTS family that we have characterized in the present work. METHODS AND RESULTS: To elucidate the electrophysiological properties of the G601S mutant channels, we expressed these channels in mammalian cells and Xenopus oocytes. The G601S mutant produced less current than wild-type channels but exhibited no change in kinetic properties or dominant-negative suppression when coexpressed with wild-type subunits. To examine the cellular trafficking of mutant HERG channel subunits, enhanced green fluorescent protein tagging and Western blot analyses were performed. These showed deficient protein trafficking of the G601S mutant to the plasma membrane. CONCLUSIONS: Our results from both the Xenopus oocyte and HEK293 cell expression systems and green fluorescent protein tagging and Western blot analyses support the conclusion that the G601S mutant is a hypomorphic mutation, resulting in a reduced current amplitude. Thus, it represents a novel mechanism underlying LQT2.

Animals↗
PubMed1999

A tourist element in the 5'-flanking region of the catalase gene CatA reveals evolutionary relationships among Oryza species with various genome types.

Tourist-OsaCatA, a transposable element, was found in the 5'-flanking region of the rice gene CatA. The characteristics of this element are similar to those of the other Tourist elements so far found in Oryza sativa. PCR and sequence analyses of 37 accessions of 18 species revealed that all the Oryza species examined, except for one accession, have either a full-length or a partial Tourist element at this locus. Unlike the Tourist elements previously reported, this Tourist element is found in all four Oryza species complexes in the Oryzeae tribe. All AA genome Oryza species, except O. longistaminata, contain the full-length Tourist element. O. longistaminata and the species of the O. officinalis, O. meyeriana and O. ridleyi complexes contain the partial element. A phylogenetic tree of Oryza species based on the nucleotide sequences of these Tourist elements was constructed. The O. longistaminata accessions were placed near the neighboring cluster of the officinalis complex. We propose that the ancestor of O. longistaminata and that of other species with the AA genome diverged, and the ancestor(s) of the O. officinalis, O. ridleyi and O. meyeriana complexes then diverged from the ancestor of O. longistaminata in the course of the evolution of the Oryza species. The Tourist elements associated with CatA and its orthologs thus provide useful tools for examining evolutionary relationships among Oryza species.

Base Sequence↗
PubMed1999

Electromyographic evaluation after endoscopic carpal tunnel release in idiopathic carpal tunnel syndrome.

The purpose of this study was to electromyographically evaluate results in patients with carpal tunnel syndrome (CTS) who underwent endoscopic carpal tunnel release (ECTR). The subjects were 26 patients with idiopathic CTS (37 hands) who were followed for at least 6 months after ECTR. To compare results informatively, hands were classified into four groups: those with normal distal motor latency (DML) and sensory conduction velocity (SCV) were classified as group A, those with normal DML and abnormal SCV as group B, those with an abnormal DML and normal SCV as group C, and those with abnormal DML and SCV as group D. All but one of the hands were classified as group D on the basis of preoperative electromyographic evaluation, while one was classified as group C. The mean preoperative obtainable DML and SCV values were 7.2 m and 27.3 m/s, respectively. Postoperatively, 12 hands were in group A, 8 hands in group B, 2 hands in group C, and 15 hands in group D. The mean DML and SCV values at final follow-up were 4.3 ms and 40.8 m/s, respectively. Of the 25 hands with muscle atrophy before surgery, 6 hands were in group A, 5 hands were in group B, 1 hand was in group C, and 13 hands were in group D at final follow-up. Thenar muscle atrophy and denervation potentials were present before surgery in 13 of the 15 hands classified as group D at the final follow-up.

Adult↗
PubMed1999

Endovascular treatment of basilar trunk aneurysm associated with fenestration of the basilar artery.

Basilar trunk saccular aneurysms associated with fenestration are infrequent, especially in the middle or distal portion of the basilar artery. Surgical treatment of the basilar trunk aneurysm is difficult, due to its anatomical environment and the complicated surgical exposure. A 46-year-old woman presenting with Hunt and Kosnik grade II subarachnoid hemorrhage was found to have a ruptured aneurysm arising at the proximal corner of the associated fenestration in the middle portion of the basilar artery. Because of surgical difficulties anticipated in approaching the aneurysm, it was decided to treat it with endovascular embolization utilizing the Guglielmi detachable coil; and complete occlusion of the aneurysm was obtained. The efficacy of endovascular treatment for the basilar trunk aneurysm with associated fenestration is discussed from anatomical and embryological points of view, and relevant literature is reviewed.

Basilar Artery↗
PubMed1999

alpha-catenin-deficient F9 cells differentiate into signet ring cells.

It has been demonstrated that alpha-catenin is frequently lost in diffuse type adenocarcinomas. We have isolated alpha-catenin-deficient mouse teratocarcinoma F9 cells by gene targeting. Wild-type F9 cell aggregates cultured in the presence of retinoic acid differentiated into embryoid bodies with an outer layer of epithelial cells. In contrast, cell aggregates of alpha-catenin-deficient cells did not develop outer layers under the same conditions. The outer surface cells of alpha-catenin-deficient cell aggregates, however, differentiated into epithelial cells as determined by their expression of epithelial marker proteins. These differentiated cells scattered from aggregates and showed signet ring cell morphology, which is frequently observed in diffuse type adenocarcinomas. We have provided clear evidence that a single mutation in the alpha-catenin gene may be a direct cause not only of the scattered properties of cells but also of signet ring cell formation in diffuse type adenocarcinoma.

Animals↗
PubMed1999

Modulation of norepinephrine release by ATP-dependent K(+)-channel activators and inhibitors in guinea-pig and human isolated right atrium.

OBJECTIVE: The aim of this study was to show, whether ATP sensitive K+ channels (KATP channels), are involved in the modulation of norepinephrine (NE) release from the sympathetic nerves innervating the guinea-pig and human right atrium. METHODS: The resting and stimulation-evoked release of [3H]norepinephrine ([3H]NE) was measured from the isolated guinea-pig and human right atrium and the effect of activators and inhibitors of ATP sensitive K+ channels was studied. RESULTS: Cromakalim (30-300 microM), a KATP channel-agonist decreased concentration-dependently the stimulation-evoked release of NE from the guinea-pig atrium, an effect, antagonized by glibenclamide, a KATP channel-antagonist (30 microM). Diazoxide (30-300 microM), another activator of the KATP channels reduced the resting release of NE, and also attenuated the evoked release at a single concentration (100 microM), and this latter action was also counteracted by glibenclamide (30 microM). Pinacidil, increased dose-dependently the resting and stimulation-evoked release of NE in a glibenclamide-sensitive manner and reversed the inhibitory effect of cromakalim (100 microM), suggesting that it acts as an antagonist. Glibenclamide (30-300 microM), by itself enhanced the stimulation-evoked release of [3H]NE, and also increased the resting release of NE. On the other hand, 5-hydroxydecanoate, an ischemia-selective inhibitor of cardiac KATP channels did not change NE release. Adenosine, (30-300 microM), an A1-receptor agonist, clonidine (3 microM), an alpha 2-adrenoceptor agonist and oxotremorine, a muscarinic receptor agonist (30 microM) all reduced the evoked release of [3H]NE, but these effects were not modified by glibenclamide (300 microM), indicating that neuronal adenosine (A1), adrenergic (alpha 2) and muscarinic (M3) receptors do not act on KATP channels. In the human right atrium, cromakalim, and diazoxide did not affect significantly the release of [3H]NE. However, glibenclamide (30-300 microM) and pinacidil (30-300 microM) enhanced dose-dependently the evoked-release of NE, and pinacidil also augmented the resting release. CONCLUSIONS: Our results indicate that sympathetic nerve endings of the human and guinea-pig atrium are endowed with ATP-sensitive K+ channels. These channels responded to agonists and antagonists under the experimental conditions applied and they could modulate the release of NE thereby affecting the autonomic control of cardiac function under various physiological and pathophysiological conditions.

Adenosine↗
PubMed1999

Radiological pathogenesis of cervical myelopathy in 60 consecutive patients with cervical ossification of the posterior longitudinal ligament.

STUDY DESIGN: The radiological pathogenetic factors for cervical myelopathy in 60 consecutive patients with cervical ossification of the posterior longitudinal ligament (OPLL) were investigated retrospectively. OBJECTIVE: To clarify which patients with OPLL will develop cervical myelopathy. METHODS: Sixty consecutive patients with OPLL were radiologically assessed comparing the myelopathic patient group (M group, n=41) and the mild or non-myelopathic patient group (non-M group, n=19). RESULTS: The narrowing ratio of the spinal canal in the M group (47.1%) was significantly greater (P=0.026) than that in the non-M group (38.3%). The two groups showed a significant difference (P=0.0016) with regard to the Pavlov ratio (M group, 0.73; non-M group, 0.84). The total range of motion of the cervical spine did not differ between the two groups but the per cent range of motion was significantly greater (P=0.037) in the M group than in the non-M group. CONCLUSION: This study suggests that factors important in the onset or aggravation of myelopathy are factors related to pathological compression by OPLL, cervical soft disc herniation, developmentally narrow spinal canal, and local or non-proportional hypermobility.

Adult↗
PubMed1999

Ventriculocisternal drainage via endoscopic third ventriculostomy after endovascular embolization for aneurysmal subarachnoid haemorrhage.

Coil embolization is a favoured method of treating acutely ruptured aneurysms. However, subarachnoid clots cannot be removed with endovascular treatment, which is disadvantageous from the view point of preventing vasospasm. The authors report intrathecal fibrinolytic therapy via a ventricular drainage tube instituted after endoscopic third ventriculostomy for effective prevention of vasospasm after coil embolization. Two cases of poor grade aneurysmal subarachnoid haemorrhage were treated with interlocking detachable coils. Following the acute stage embolization, endoscopic third ventriculostomy was performed and a drainage tube was inserted into a lateral ventricle or basal cistern. Intrathecal fibrinolytic therapy with Urokinase was performed via the drain tube to a spinal drain. In both cases, the subarachnoid clot disappeared rapidly without any clinical signs of vasospasm. Copyright 1999 Harcourt Publishers Ltd.

Journal Article↗
PubMed1999

Systemically administered interleukin-10 reduces tumor necrosis factor-alpha production and significantly improves functional recovery following traumatic spinal cord injury in rats.

In these studies, we examined the neuroprotective effects of the potent antiinflammatory cytokine interleukin-10 (IL-10) following spinal cord injury (SCI). Neuroprotection was assessed by using behavioral and morphological end points. We hypothesized that injury-induced inflammation contributes to the resulting neuropathology and subsequent loss of function. Therefore, by attenuating injury-induced inflammation, we should promote functional recovery. The New York University device was used to induce moderate SCI and study the resulting inflammatory response and functional consequences of inhibiting this response in rats. We determined that SCI induces the expression of tumor necrosis factor-alpha (TNF-alpha) in the spinal cord and by SCI-activated monocytes isolated from the peripheral circulation. IL-10 (5.0 microg) administered 30 minutes after-injury significantly reduced the expression of TNF-alpha protein in the spinal cord and in vitro by SCI-activated monocytes. Next, we investigated whether IL-10 would improve functional recovery after SCI. Randomized, double-blinded studies demonstrated that a single injection of IL-10 significantly improves hind limb motor function 2 months after injury, as determined by the Basso, Beattie and Bresnahan (BBB) open-field behavioral test. IL-10-treated animals had a mean BBB score of 18.0+/-0.5 (SEM, n = 9) compared with a score of 12.9+/-0.6 (SEM, n = 9) for the saline-treated controls. Morphological analysis demonstrated that IL-10 reduces lesion volume by approximately 49% 2 months after injury. These data suggest that acute administration of IL-10 reduces TNF-alpha synthesis in the spinal cord and by activated macrophages, is neuroprotective, and promotes functional recovery following SCI.

Animals↗
PubMed1999

Cryopreservation of bovine pre-morula-stage in vitro matured/in vitro fertilized embryos after delipidation and before use in nucleus transfer.

We have determined that the tolerance of in vitro matured/in vitro fertilized (IVM/IVF) bovine embryos to cryopreservation at the pre-morula stage can be improved by removal of cytoplasmic lipid droplets by centrifugation. Nucleus transfer was also performed using cryopreserved, delipated (lipid droplets removed) 8- to 16-cell-stage blastomeres of IVM/IVF embryos as donor nuclei. In vitro developmental ability of the delipated embryos to the blastocyst stage (20 of 126) was found to be equal to that of undelipated embryos (35 of 176); and of 53 delipated embryos cryopreserved at the 8- to 16-cell stage, 12 developed into blastocysts in vitro after thawing. On the other hand, only 2 of 43 undelipated embryos and 5 of 59 sham-operated embryos survived (p < 0.05). When blastomeres isolated from cryopreserved, delipated 8- to 16-cell-stage embryos were used for nucleus transfer, 57 of 80 successfully fused with enucleated oocytes, which was significantly lower than the fusion rate obtained with blastomeres of unfrozen, undelipated embryos (93 of 104, p < 0.01). However, the developmental rate to the blastocyst stage for nucleus transfer embryos reconstituted with frozen, delipated blastomeres (9 of 57) was not different from that of the nucleus transfer embryos with unfrozen, undelipated embryos (23 of 93). These results confirm that removal of cytoplasmic lipid droplets from bovine IVM/IVF zygotes allows for successful cryopreservation at the 8- to 16-cell stage and that blastomeres from these embryos can be used as donors of karyoplasts for nucleus transfer.

Animals↗
PubMed1999

Evaluation of neuromuscular and cardiovascular effects of two doses of rapacuronium (ORG 9487) versus mivacurium and succinylcholine.

BACKGROUND: This study compares the neuromuscular blocking and cardiovascular effects of rapacuronium (ORG 9487), a new aminosteroid nondepolarizing muscle relaxant, to recommended intubating doses of succinylcholine and mivacurium. METHODS: Adult patients were randomized in an open-label fashion to receive 1-5 microg/kg fentanyl before 1.5 mg/kg propofol induction followed by 1.5 or 2.5 mg/kg rapacuronium, 1.0 mg/kg succinylcholine, or 0.25 mg/kg mivacurium (i.e., 0.15 mg/kg followed by 0.1 mg/kg 30 s later). RESULTS: Patient neuromuscular blockade status was monitored by measuring the train-of-four response to a supramaximal stimulus at the ulnar nerve every 12 s. Percentage of the first twitch of the train-of-four (T1) at 60 s was similar in patients receiving 1.5 mg/kg rapacuronium, 2.5 mg/kg rapacuronium, and succinylcholine and was significantly less than in patients in the mivacurium group (26, 16, and 18%, respectively, vs. 48%; P < 0.01). Times to 80% T1 depression were also similar among patients in the 1.5 mg/kg rapacuronium, 2.5 mg/kg rapacuronium, and succinylcholine groups and significantly longer in the mivacurium group (62, 54, and 54 s, respectively, vs. 112 s; P < 0.01). Clinical duration was longer in all groups compared with the succinylcholine group; however, clinical duration in the 1.5 mg/kg rapacuronium group was shorter compared with the mivacurium group (15 vs. 21 min, respectively; P < 0.01). Heart rate changes were mild in the 1.5 mg/kg rapacuronium, succinylcholine, and mivacurium groups. The patients in the 2.5 mg/kg rapacuronium group had significantly higher heart rates compared with patients in the mivacurium group. No differences were found in blood pressure changes among patients in the four groups. CONCLUSIONS: Rapacuronium, 1.5 and 2.5 mg/kg, produced neuromuscular blockade as rapidly as succinylcholine and significantly faster than mivacurium. Although succinylcholine continued to show the shortest duration, 1.5 mg/kg rapacuronium used a rapid onset and a relatively short duration and may be considered an alternative to succinylcholine.

Adult↗
PubMed1999

Abscess forming ability of streptococcus milleri group: synergistic effect with Fusobacterium nucleatum.

The abscess forming abilities of "Streptococcus milleri" strains (Streptococcus constellatus, Streptococcus anginiosus, and Streptococcus intermedius) isolated from dentoalveolar abscesses and the synergistic effect of Fusobacterium nucleatum co-inoculated with the isolates were examined on a mouse subcutaneous abscess model. Five days after inoculation, all S. milleri strains formed abscesses, which showed less pathological spread to surrounding connective tissues than those formed by Staphylococcus aureus 209P strain and were similar to those by F. nucleatum ATCC25586. When each S. milleri strain and F. nucleatum were co-inoculated, abscess sizes and each bacterial number recovered from abscesses increased in comparison to those treated by bacterial mono-inoculation of each S. milleri strain or F. nucleatum alone. The strongest synergistic effect was observed in the combination of S. constellatus and F. nucleatum. In a time course experiment with this combination, the recovery of S. constellatus subsequently decreased after the decrement of F. nucleatum, and it appeared that the association with F. nucleatum maintained the bacterial number of S. constellatus in the abscess. The cell-free supernatant of F. nucleatum had a tendency to increase the abscess size caused by S. constellatus in this model. When S. constellatus was cultured with F. nucleatum culture supernatant in vitro, growth enhancement in the early phase was observed. Furthermore, the phagocytic killing of S. constellatus by human polymorphonuclear leukocytes (PMNs) was significantly suppressed and the PMN membranes appeared to be injured by addition of the F. nucleatum culture supernatant. These results suggest that the pathogenicity of S. milleri strains in odontogenic infections may be enhanced by the co-existence of F. nucleatum.

Abscess↗