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D Okada

Publications and source records attributed to D Okada.

At least 19 recordsLinked to original sources
PubMed2005

[Concomitant off-pump coronary artery bypass and left lower lobectomy for lung cancer with pneumoconiosis].

Surgical strategy for patients for lung cancer with coronary disease remains controversial. We performed concomitant off-pump coronary artery bypass grafting (off-pump CABG: OPCAB) and left lower lobectomy with ND 2a lymph nodes dissection for lung cancer with pneumoconiosis. After CABG, due to fixed adhesion of peribronchial lymph node, left lower lobectomy was hard to carry out. Postoperative management was done with much difficulty for massive sputum and pneumonia caused by chronic inflammatory lung disease. As a result, postoperative course has been uneventful for 2 years after operation. In the concomitant OPCAB and lung resection with chronic inflammatory lung disease, whether the synchronous or 2 periods operation was appropriate was still unknown. We think that careful pre- and intraoperative assessment for this disease is important.

Aged↗
PubMed2004

Distinct glutamate receptors govern differential levels of nitric oxide production in a layer-specific manner in the rat cerebellar cortex.

To evaluate roles of nitric oxide (NO) in neural functions, it is critical to know how neural inputs activate neuronal NO synthase in individual sites. Although NMDA receptor-dependent mechanism well explains postsynaptic, robust NO production, this sole mechanism does not explain some aspects of NO production in the brain, such as the low-level production of NO and the mechanism for presynaptic NO production. We hypothesized that the glutamate receptor involved in NO production is site-specific and controls the initial NO concentration in each site. We visualized NO production mediated by NMDA, AMPA and type-1 metabotropic glutamate (mGlu-1) receptors in rat cerebellar slices and granule cells in culture, with an NO-specific fluorescent indicator, diaminofluorescein-2. AMPA receptor, but not NMDA or mGlu-1 receptor, was responsible for NO production at parallel fiber terminals, which was blocked by CNQX, tetrodotoxin or voltage-dependent calcium channel blockers. More numbers of electrical stimulation were required for NO production in the molecular layer than in other layers, suggesting that AMPA receptor activation generates NO at lower concentrations through a remote interaction with NO synthase. Although Purkinje cell does not express NO synthase, we detected NO production in Purkinje cell layer following electrical stimulation in the white matter at 50 Hz, but not at 10 Hz. This NO production was tetrodotoxin-sensitive, suggesting occurrence in the basket cell terminals, and required synergistic activation of mGlu-1 and NMDA receptors. In the granule cell layer, activation of AMPA or mGlu-1 receptor produced NO uniformly, while NMDA receptor activation produced NO in discontinuous areas of this layer. Thus, distinct glutamate receptors, including non-NMDA receptors, govern occurrence and level of NO production in a layer-specific manner.

Anesthetics, Local↗
PubMed2003

Sast124, a novel splice variant of syntrophin-associated serine/threonine kinase (SAST), is specifically localized in the restricted brain regions.

Syntrophin is an adaptor protein that binds signaling molecules to the dystrophin-associated protein complex, which connects extracellular matrix to intracellular cytoskeleton for construction and maintenance of the postsynaptic structures in the neuromuscular junction and the CNS. Among these signaling molecules, a family of microtubule-associated serine/threonine kinases has a unique structural feature with a serine/threonine kinase domain and a postsynaptic density protein-95/discs large/zona occludens-1 domain. In the present study, we identified syntrophin-associated serine/threonine kinase-124, a novel splice variant of the syntrophin-associated serine/threonine kinase which is a member of the microtubule-associated serine/threonine kinases family. Comparing to the original clone (syntrophin-associated serine/threonine kinase-170), syntrophin-associated serine/threonine kinase-124 is truncated just downstream of the postsynaptic density protein-95/discs large/zona occludens-1 domain. Using a monoclonal antibody specifically recognizing syntrophin-associated serine/threonine kinase-124, strong expression of the protein was observed in neurons of the subventricular zone and granule cells of the olfactory bulb, Islands of Calleja, hippocampal dentate gyrus and cerebellum. syntrophin-associated serine/threonine kinase-124 is selectively localized in the nuclei of neurons and distinct from syntrophin-associated serine/threonine kinase-170, which is interacting with syntrophin on the cell surface. Considering the tissue and subcellular distributions of syntrophin-associated serine/threonine kinase-124, it is suggested that syntrophin-associated serine/threonine kinase-124 may have functions in transcriptional regulation for the features commonly shared by these neurons. On the other hand, syntrophin-associated serine/threonine kinase-124 was also localized in glia-like cell bodies in the corpus callosum and fiber bundles in the spinal trigeminal and solitary tracts, suggesting syntrophin-associated serine/threonine kinase-124 may have other functions in these types of cells.

Amino Acid Sequence↗
PubMed2003

[The evaluation of the complications and its management in 800 patients who underwent the thoracoscopic surgery].

Thoracoscopy has been applied to almost all thoracic surgery as shown (table 1). Besides an opportunity to follow and encounter a trouble during surgery using thoracoscopy, so that it is necessary to become skilled in the prediction and management of complication. Nowadays, there are two options on surgery using thoracoscopy, thoracoscopic surgery (TS) is performed only on in a port and on a mini-thoracotomy with a few ports (video-assisted thoracoscopic surgery: VATS). When changing into emergency or converting into open thoracotomy, a muscle sparing thoracotomy could be available. The symptoms which occurred in the thorax are fundamentally similar during both TS and VATS procedure. However, peculiar dangerous factor existed according to the difference in internal organs, procedures, and diseases. Critical complications during surgery were as follows, i.e., injury of pulmonary vessels and bronchus, tension pneumothorax of the opposite lung and tumor implantation of the chest wall. Basically, standard practice is the most important to avoid an accident and determine whether converting to open thoracotomy should be employed. In the present commentary, we would like to present our experiences and propose regarding management.

Bronchi↗
PubMed2001

Intercellular action of nitric oxide increases cGMP in cerebellar Purkinje cells.

cGMP is thought to play a role in cerebellar signalling yet its production within Purkinje cells has never been detected. In the present study, the hydrolysis of a fluorescent substrate analogue, 2'-O-anthranyloyl cyclic GMP, by type 5 phosphodiesterase was monitored within Purkinje cells in slices and in culture. Nitric oxide, either endogenously released from adjacent neurons or pharmacologically applied, accelerated the rate of hydrolysis in a manner that was dependent on soluble guanylyl cyclase, demonstrating that nitric oxide triggers cyclic GMP production in Purkinje cells, which in turn activates type 5 phosphodiesterase. We conclude that NO acts as an intercellular messenger in the cerebellar cortex and that parallel fibre terminals are a probable source of nitric oxide.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed2001

High survival rate of 6 cases of pulmonary large cell neuroendocrine carcinoma formerly classified as small cell carcinoma.

UNLABELLED: In the revised WHO classification of lung cancer, published in 1999, large cell neuroendocrine carcinoma (LCNEC) was employed as a new histological entity. LCNEC is generally considered a high-grade malignant lung cancer, and appropriate treatment remains to be determined. Before its new classification, LCNEC had long been classified into several entities. Advancing the review of previous cases in Nippon Medical School Hospital, we noticed that some LCNEC patients were formally diagnosed as having small cell lung cancer (SCLC), and they showed long-term survival. MATERIAL AND METHODS: All histological specimens of surgically resected SCLC in Nippon Medical School Hospital were reclassified according to the 1999 WHO classification manual. Their neuroendocrine differentiations were confirmed by the use of immunostainings with chromogranin A and synaptophysin. RESULTS: Fourteen cases satisfied the qualifications for both histological and clinical reevaluation. Among them, 6 patients were reclassified as LCNEC, and their stage distribution was as follow: IA; 1, IB; 2, IIIA; 2, and IIIB; 1. Their survival term ranged from 33.8 to 78.0 months; 5 were still alive, and 1 (IIIB) died 57.6 months after surgery. DISCUSSION: According to this study, all the LCNEC patients who were treated as SCLC patients showed more favorable prognoses than patients described in published studies, even overall lung cancer. Therefore, it is suggested that multimodality therapy for SCLC may improve the prognoses of patients with LCNEC.

Aged↗
PubMed2000

Neutral red as a hydrophobic probe for monitoring neuronal activity.

Neutral red fluorescence has been used to monitor neuronal activity. Local changes in either pH or hydrophobicity are reported to increase neutral red fluorescence, but the mechanisms underlying the increases remain unclear. In this study, the pH-dependent fluorescence changes in the basic and acidic forms of neutral red preloaded in rat cerebellar slices were separately measured with two excitation wavelengths. Bath application of kainate, domoate or alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) at 1 mM increased fluorescence of the acidic form and decreased that of the basic form irreversibly, consistent with a pH-dependent mechanism. In contrast, application of lower concentrations of AMPA, (S)-3,5-dihydroxyphenylglycine or KCl increased fluorescence of both forms transiently, suggesting that a pH-independent mechanism may also increase neutral red fluorescence. Electrical stimulation in the molecular layer also increased fluorescence of both forms. The response to weak electrical stimulation decayed in about 1 s, while response to intense stimulation lasted longer than 1 min. Neutral red binding to phospholipids was also detected as fluorescent spots on thin-layer chromatography, suggesting that interaction with phospholipids enhances neutral red fluorescence. Thus, the short-lasting signal of neutral red suggests its usage as a hydrophobic probe for neuronal activity.

Animals↗
PubMed1999

Corticotropin-releasing factor plays a permissive role in cerebellar long-term depression.

This study of rat cerebellar slices yielded two lines of evidence indicating that the corticotropin-releasing factor (CRF) found in climbing fibers (CFs) is critical for the induction of long-term depression (LTD) at the parallel fiber (PF) synapses of Purkinje cells (PCs) by their conjunctive activation with either stimulation of CFs or depolarization of PCs. First, LTD induction was effectively blocked by specific CRF receptor antagonists, alpha-helical CRF-(9-41) (alpha-h CRF) and astressin; and second, LTD was no longer observed in CF-deprived cerebella but was restored by CRF replenishment. The data obtained in this study suggest that these effects are mediated by protein kinase C (PKC) and not by Ca2+ signaling or cyclic GMP (cGMP) production.

Animals↗
PubMed1999

[Statistical analysis of fabrication of indirect single restorations].

A statistical survey based on laboratory records was performed on the number of indirect restorations fabricated at the dental hospital of Tokyo Medical and Dental University from April 1 to September 30, 1997. A comparison was also carried out with a previous survey, which had been carried out in 1986, in order to detect any change and possible alterations in the near future. Based on the results of this statistical survey, the conclusions were as follows: 1. A total of 9,126 indirect restorations were fabricated during the six month period in 1997; among them, 8,007 (87.7%) restorations were covered by health insurance and 1,119 (12.3%) restorations were not. 2. The most common restoration was the cast post and core (28.6%), followed by full crowns (18.5%) and removable partial dentures (15.6%). On the other hand, the least number were post crowns (0.03%) and resin jacket crowns (0.2%). 3. When making a comparison with the data in 1986, an increase in the number of removable partial dentures and a decrease in the number of inlays were the most distinctive features. 4. For anterior teeth, resin-veneered crowns were most common, especially for lower teeth. The percentage of restorations, which were not covered by health insurance, decreased from 45.0% (in 1986) to 12.3% (in 1997).

Crowns↗
PubMed1999

[Statistical analysis of fabrication of fixed and removable partial dentures].

A statistical survey based on laboratory records was performed on the number of fixed and removable partial dentures fabricated at the dental hospital of Tokyo Medical and Dental University from April 1 to September 30, 1997. A comparison was also performed with a previous survey, which had been carried out in 1986, in order to detect any change and possible alterations in the near future. From the findings of this statistical survey, the conclusions were as follows: 1. A total of 2,478 fixed and removable partial dentures were fabricated during the six month period in 1997. 2. The 3-unit fixed partial denture (bridge) was most common (63.1%) and the number of bridges decreased as the number of units increased. 3. For the single missing tooth, a fixed bridge was more popular (81.0%) than a removable partial denture. 4. For two missing teeth, there was no difference between the number of fixed bridges and removable partial dentures. 5. The percentage of fixed and removable partial dentures, which were not covered by health insurance, decreased to a large extent in comparison with the survey in 1986.

Denture, Partial, Fixed↗
PubMed1998

Tetrahydrobiopterin-dependent stabilization of neuronal nitric oxide synthase dimer reduces susceptibility to phosphorylation by protein kinase C in vitro.

Binding of (6R)-5,6,7,8-tetrahydro-L-biopterin (H4B) stabilizes the homodimeric structure of neuronal nitric oxide synthase (nNOS). In the present study, low-temperature sodium dodecylsulfate-polyacrylamide gel electrophoresis revealed differential susceptibility of stabilized and non-stabilized dimers to in vitro phosphorylation by protein kinase C. Protein kinase C preferentially phosphorylated the non-stabilized dimer. Although a low extent of phosphorylation was detected in the stabilized dimer, most of it was estimated to be due to phosphorylation of the dimer before its stabilization. Phosphorylation did not affect the stabilizing effect of H4B. These results indicate that H4B-dependent dimer stabilization prevents nNOS from protein kinase C-dependent phosphorylation in vitro.

Animals↗
PubMed1998

The measurement of physiological tooth displacement in function.

The purpose of this work was to investigate the physiological tooth displacement in function. We developed the tooth displacement transducer Type M-3 and measured the three dimensional displacement of the upper and lower left first molars in function. The summary is as follows: 1. Magnesensors were used in the tooth displacement transducer Type M-3. Its total weight was 48.7 g. and the measuring pressure was kept less than 0.4 g. It was fixed at the labial surface of the anterior teeth using a paraocclusal splint. 2. The linearity error of the transducer was less than 2% within a range of +/-200 microm. 3. The upper left first molar showed displacement in the palatal and apical direction during clenching at the intercuspal position with habitual occlusal force or during the biting of articulating papers. The displacement varied between 40 and 136 microm. 4. The lower left first molar showed displacement in the apical and lingual direction during clenching at the intercuspal position or during the biting of articulating papers. The displacement varied between 29 and 65 microm. 5. The upper left first molar showed displacement in the palatal and apical direction during mastication. The displacement varied between 68 microm and 79 microm. The upper teeth moved first in the apical direction, then moved toward the labial direction. 6. In the lingual direction, the lower left first molar showed displacement ranging from 11 to 71 microm and 17 to 39 microm in the buccal direction during mastication.

Adult↗
PubMed1998

A clinical study on abutment taper and height of full cast crown preparations.

Dental students at Tokyo Medical and Dental University are taught to prepare teeth for full cast crowns with a wall taper of 2 to 5 degrees and an occlusal clearance of 1.2 to 1.5 mm. However, it is difficult to achieve such an ideal taper. The objective of this study was to examine the abutment taper and height of teeth prepared for crowns by final-year dental students under clinical supervision. To evaluate the degree of taper and height of the prepared teeth, shadowgraphs of 63 working stone dies were traced. The angles and height of the abutments were then measured on the same tracing. Only 12.7% (8 out of 63 abutments) of the prepared teeth fell within the ideal range of 2 to 5 degrees, and the average taper was 9.5 degrees (19.0 degrees convergence angle). The average abutment height varied from 4.8 mm to 6.9 mm and showed a close relationship with the abutment taper. The average taper, 9.5 degrees, of the present study was larger than the ideal taper; however, it was thought to be clinically acceptable as it is difficult to achieve the ideal taper intraorally.

Crowns↗
PubMed1997

Study of regional cerebral oxygen saturation during percutaneous cardiopulmonary support.

The purpose of this study was to evaluate the change of regional cerebral oxygen saturation (rSO2) during percutaneous cardiopulmonary support (PCPS) in patients with cardiogenic shock. Fifteen patients with cardiogenic shock were evaluated during PCPS by continuous monitoring of rSO2, systemic venous oxygen saturation (Svo2), and hemodynamics. The brain damage of these patients was also evaluated during and after PCPS. There were 10 males and 5 females. Their ages ranged from 57 to 79 years old (average: 60.0 +/- 14). Two patients were unconscious before PCPS, and 11 received intraaortic balloon pumping (IABP) before PCPS. The change of rSO2 was significantly correlated with the change of Svo2. The average of rSO2 was 64 +/- 3% at the stable hemodynamic condition. The rSO2 with pulsatile PCPS was higher than that with nonpulsatile PCPS. There was no correlation between brain damage and rSO2. The patients with low rSO2 (< 50%) that resulted in poor LV function could not be weaned from PCPS. In conclusion, the continuous monitoring of rSO2 during PCPS could be a useful tool.

Aged↗
PubMed1996

Zinc protoporphyrin IX suppresses nitric oxide production through a loss of L-arginine in rat cerebellar slices.

Zinc protoporphyrin IX (ZnPP) inhibits production of carbon monoxide (CO) but not nitric oxide (NO) synthase activity in vitro, therefore, it has been used to discriminate the effects of these activators of cyclic GMP production. However, intracellular enzyme activity is supported by endogenous substrates and cofactors, therefore, in vitro experiments with an optimal supply of these substances do not necessarily represent the intracellular circumstances. The present study was conducted to examine whether ZnPP affects NO production in rat cerebellar slices. Incubation with 1-aminocyclopentane-trans-1,3-dicarboxylic acid (ACPD) increased the conversion of [3H]-L-arginine into [3H]-citrulline in the slices. ZnPP at I microM, not only suppressed the ACPD-dependent production of [3H]-citrulline but also reduced the basal [3H]-citrulline level, accumulation of [3H]-L-arginine and ATP content in the slices, but ZnPP at 1 microM did not affect the catalytic activity of partially purified NO synthases in vitro. In contrast, a selective inhibitor of NO synthase, N omega(-)nitro-L-arginine, inhibited ACPD-dependent [3H]-citrulline production without affecting the basal [3H]-citrulline level or [3H]-L-arginine accumulation. These results indicate that ZnPP suppresses No production through a loss of its precursor, even at concentrations exhibiting no inhibition of the catalytic activity of NO synthase. It is concluded that ACPD activates NO synthase in the slice and that ZnPP cannot discriminate the roles of CO from NO in cyclic GMP production in brain slices.

Animals↗