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Biomedical subjects

S Miyoshi

Publications and source records attributed to S Miyoshi.

At least 19 recordsLinked to original sources
PubMed2006

Observation and control of transverse energy-transport barrier due to the formation of an energetic-electron layer with sheared ExB flow.

Off-axis electron-cyclotron heating in an axisymmetric barrier mirror produces a cylindrical layer with energetic electrons, which flow through the central cell and into the end region. The layer, producing a localized bumped ambipolar potential Phi(C), forms a strong shear of radial electric fields E(r) and peaked vorticity with the direction reversal of E(r)xB sheared flow near the Phi(C) peak. Intermittent vortexlike turbulent structures near the layer are suppressed in the central cell by this actively produced transverse energy-transport barrier; this results in T(e) and T(i) rises surrounded by the layer.

Journal Article↗
PubMed2006

The effect of ephedrine and phenylephrine on BIS values during propofol anaesthesia.

BACKGROUND: The purpose of this study was to evaluate the effect of ephedrine and phenylephrine on propofol concentrations and bispectral index during propofol anesthesia. METHODS: General anaesthesia was induced with propofol and was maintained with propofol (4 mg kg-1 h-1) and fentanyl. Vecuronium was used to facilitate the artificial ventilation of the lungs. Patients with systolic blood pressure > 90 mmHg were defined as the control group (n = 16). Patients who had to be treated for larger decreases in arterial blood pressure (systolic blood pressure 60, whereas no patient in the control or phenylephrine groups had bispectral index >60. There were no significant differences in propofol concentrations or cardiac output relative to baseline at 3 or 10 min after the administration of ephedrine or phenylephrine. CONCLUSIONS: Ephedrine increases bispectral index values without decreasing propofol concentrations during general anesthesia.

Anesthesia, Intravenous↗
PubMed2005

Observation of the effects of radially sheared electric fields on the suppression of turbulent vortex structures and the associated transverse loss in GAMMA 10.

Vortexlike turbulent structures in hot-ion mode plasmas with several keV are observed in the case with a radially produced weak shear of electric fields E(r). However, a strong E(r) shear formation due to a high ion-confining potential phi(c) production clears up these vortices together with plasma-confinement improvement and disappearance of both drift-wave and turbulencelike Fourier spectral signals. These findings are based on three-time progress in phi(c) in comparison to phi(c) attained 1992-2002. The significant advance of phi(c) is well extended in line with proposed potential-formation physics scalings.

Journal Article↗
PubMed2004

Hemi-clamshell approach for advanced primary lung cancer.

BACKGROUND: The hemi-clamshell approach provides a wide anterior view of the mediastinum, apical dome, and cervicothoracic area. However, only a few reports have been made regarding this technique. METHODS: The hemi-clamshell approach was used in 24 patients, of whom 5 had a Pancoast tumor, 15 had mediastinal involvement, and 4 underwent mediastinal lymphadenopathy for left-sided lung cancer. Twenty-one of the patients received preoperative therapy. RESULTS: Twenty-one operations were complete resections. In addition, 12 patients received cardio-vascular reconstruction and 5 a first rib resection. Postoperative major morbidity was 21 % (6/24) and mortality was 4.2 % (1/24). Nine patients died of systemic tumor relapse and 14 patients were alive after a median follow-up of 24 months (range 3 - 68 months) following the initial therapy. The 5-year survival rate of patients with mediastinal involvement was 37 % and that of 13 patients with postoperative stage I or II was 35 %. CONCLUSIONS: The hemi-clamshell approach provides a wide exposure allowing a safe and complete removal of lung cancer that involves the mediastinum and apical thoracic dome, leading to a better long-term survival rate for patients with this disease.

Adenocarcinoma↗
PubMed2004

Absence of mutations in the Wilms' tumor gene wt1 in de novo non-small cell lung cancers.

We recently demonstrated that the WT1 gene was overexpressed in the majority of de novo lung cancers regardless of cancer subtypes. Here, we examined WT1 genomic DNA in 38 cases of de novo non-small cell lung cancers (NSCLC) for mutations using direct sequencing. The sequencing analysis showed no mutations of WT1 genomic DNA in any of 38 de novo non-small cell lung cancers examined. These results indicated that the non-mutated, wild-type WT1 gene played an important role in de novo NSCLC.

Adult↗
PubMed2004

[Pulmonary thromboendarterectomy for an elderly patient].

We describe a case of successful pulmonary thromboendarterectomy for an elderly patient. A 75-year-old female suffered from severe dyspnea in spite of administration of pulmonary vascular dilators and anticoagulants. Her pulmonary vascular resistance was 545 dyn x sec x cm(-5) and, her pulmonary angiogram and perfusion scan revealed that almost all branches of her right pulmonary artery were occluded. Pulmonary thromboendarterectomy was performed under cardiopulmonary bypass. A videoscope was employed to see inside of the pulmonary artery. Flexible aspirator chip was used to peed abnormal intima easily. A non-invasive intracranial oxygen saturation monitor was used for secure circulatory arrest. The duration of cardiopulmonary bypass was 101 minutes and minimum body temperature was 24.5 degrees C. Her symptoms improved markedly after operation, and she went back to the ordinary life. Pulmonary thromboendarterectomy was useful even for elderly patients under some modifications of the operative procedures.

Aged↗
PubMed2004

[Pulmonary embolectomy followed by lobectomy to treat for massive endobronchial bleeding; report of a case].

We describe a case of successful pulmonary embolectomy that required lobectomy to treat for endobronchial bleeding. Sixty-nine-year-old female got into shock required CPR during rehabilitation after replacement of femur head. Her enhanced computed tomography (CT) showed massive embolism in pulmonary artery. Emergency embolectomy was performed under cardiopulmonary bypass (CPB). A videoscope was employed to see inside the pulmonary artery. At the end of the CPB, endobronchial bleeding occurred. The right bronchus was occluded by balloon and CPB was weaned. The right lower lobectomy was done on the next day. She had got pyothorax by methicillin-resistant Staphylococcus aureus (MRSA), and has recovered after intravenous administration of antibiotics and continuous wash out of pleural space by saline containing 0.02% povidon-iodine. Postoperative scan showed no defects of blood flow and ventilation except resected lobe.

Aged↗
PubMed2003

[Surgical treatment for pulmonary metastasis from submandibular gland cancer].

We reviewed surgical result of 5 patients with pulmonary metastasis from submandibular gland cancer. Pathological diagnosis was adenoid cystic carcinoma in 2 patients, carcinoma in pleomorphic adenoma in 1, epidermoid carcinoma in 1, and mucoepidermoid tumor in 1. Disease free interval from resection of the primary lesion to diagnosis of pulmonary metastasis was ranging from 7 to 76 months. Lobectomy was performed in 2 patients and partial lung resection in 3. Three patients died of tumor recurrence 12 to 28 months after lung resection and 2 patients with a single metastatic lesion have survived as long as 42 and 150 months after the operation. This study suggests that surgical treatment may be effective for pulmonary metastasis, especially for a single metastatic lesion, from submandibular gland cancer.

Adult↗
PubMed2003

[Usefulness of mini loop retractor in video-assisted thoracic surgery].

We have developed a technique using a Mini Loop Retractor II and successfully performed video-assisted thoracoscopic surgery (VATS) in 32 patients. It is inserted into the pleural cavity through a skin puncture and a loop at its distal end is easily, and is freely adjustable in dimensions so that it can act as a retractor or holding forceps. Mini Loop Retractor II was very useful instruments in VATS.

Humans↗
PubMed2002

[Cavernous hemangioma in the anterior mediastinum; report of a case].

A rare case of mediastinal hemangioma was reported in this article. A 63 years old male was pointed out an abnormal shadow in the chest CT scan though he had no symptoms. It showed a well-defined round mass with low density in the anterior mediastinum. MRI (T2 weight) showed the lesion as a high intensity tumor. We diagnosed it thymoma and planned the surgical treatment. The tumor was resected completely through median partial sternotomy. The tumor was 2 cm in diameter. Histological examination revealed it cavernous hemangioma, and neither coagulations nor phleboliths were identified in vessels of the tumor.

Hemangioma, Cavernous↗
PubMed2001

A transmembrane trap method for efficient cloning of genes encoding proteins possessing transmembrane domain.

To facilitate searching for genes encoding cell membrane proteins, we developed a method for isolating cDNAs that contain sequences for hydrophobic transmembrane runs. This cloning strategy, termed the "transmembrane (TM) trap method," utilizes a vector that directs the cell surface expression of mouse CD4 fusion protein when an insert encoding hydrophobic transmembrane sequences is cloned in-frame with correct orientation. We applied this novel method to isolation of cytokine receptor cDNAs. Our strategy enabled efficient isolation of relatively rare species encoding receptors such as IL-2Rgamma, IL-3Rbeta, IL-4Ralpha, IL-5Ralpha, and IL-6Ralpha. This method also could be used to isolate cDNAs for intracellular molecules with a transmembrane region, e.g., bcl-2. These results indicate that the TM trap method provides an efficient cloning strategy for identification of various families of genes encoding proteins with one or more transmembrane regions.

Animals↗
PubMed2001

Potassium channel blocker activates extracellular signal-regulated kinases through Pyk2 and epidermal growth factor receptor in rat cardiomyocytes.

OBJECTIVES: We sought to determine whether potassium (K(+)) channel blockers (KBs) can activate extracellular signal-regulated kinase (ERK) and to characterize the upstream signals leading to ERK activation in cardiomyocytes. BACKGROUND: Because KBs attenuate K(+) outward current, they may possibly prolong the duration of action potentials, leading to an increase in calcium (Ca(2+)) transient ([Ca(2+)](i)) in cardiomyocytes. Elevation of intracellular Ca(2+) levels can trigger various signaling events. Influx of Ca(2+) through L-type Ca(2+) channels after membrane depolarization induced activation of MEK and ERK through activation of Ras in neurons. Although KBs are frequently used to treat cardiac arrhythmias, their effect on signaling pathways remains unknown. METHODS: Primary cultured rat cardiomyocytes were stimulated with four different KBs-4-aminopyridine (4-AP), E-4031, tetra-ethylammonium and quinidine-and phosphorylation of ERK, proline-rich tyrosine kinase 2 (Pyk2) and epidermal growth factor receptor (EGFR) was detected. Action potentials were recorded by use of a conventional microelectrode. (Ca(2+))(i) was monitored by the fluorescent calcium indicator Fluo-4. RESULTS: E-4031, 4-AP, tetra-ethylammonium and quinidine induced phosphorylation of ERK. 4-Aminopyridine prolonged the duration of action potentials by 37% and increased (Ca(2+))(i) by 52% at 1 mmol/l. Pre-incubation of ethyleneglycoltetraacetic acid, 1,2-bis(2-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid tetrakis and diltiazem completely blocked this phosphorylation, whereas flufenamic acid and benzamil did not. 4-Aminopyridine induced tyrosine phosphorylation of Pyk2 and EGFR, which peaked at 5 and 10 min, respectively. Cytochalasin D, AG1478 and dominant-negative EGFR strongly inhibited the phosphorylation of ERK, whereas calphostin C, calmidazolium and KN62 did not. CONCLUSIONS: These findings indicate that KBs induce ERK activation, which starts with Ca(2+) entry through the L-type Ca(2+) channel in cardiomyocytes, and that EGFR and Pyk2 are involved in this activation.

4-Aminopyridine↗
PubMed2001

Effects of propylene glycol drenching on energy balance, plasma glucose, plasma insulin, ovarian function and conception in dairy cows.

We postulated that daily drenching of propylene glycol to cows in early lactation would increase plasma glucose and insulin concentrations and improve fertility in postpartum cows. Thirty-six Holstein cows were assigned to treatment or control groups. Each treatment cow was given 500 ml of propylene glycol by drenching daily from 7 to 42 days of lactation. Blood samples for glucose, insulin, nonesterified fatty acids (NEFA), and plasma urea N were collected at 0, 30, and 90 min postdrenching once weekly during 1-6 weeks. Blood samples were collected for progesterone analysis and cows were palpated three times per week until 11 weeks to assess ovarian status. Propylene glycol did not affect dry matter intake (DMI), milk yield or energy balance in treatment cows. After drenching, propylene glycol increased (P<0.01) plasma glucose and insulin and decreased (P<0.01) NEFA; plasma urea N of the treatment group tended (P=0.07) to be higher than that of the control group through 90 min. Days to first service, days open, and services per conception were not different between groups. Conception rates to first insemination were 33% in the control group and 57% in treated cows, but these were not significantly different. First ovulation of treatment cows occurred earlier than that of control cows (32.3 versus 44.5 days, P=0.06) and the length of the first luteal phase was longer in treated cows (13.1 versus 7.3 days, P<0.05). These data are consistent with the hypothesis that insulin is important for normal ovarian function. During negative energy balance, treatment with propylene glycol, which induced small increases in plasma concentrations of insulin, prevented the short luteal phase characteristic of the first estrous cycle in control cows.

Animals↗
PubMed2001

Generalized scaling laws of the formation and effects of plasma-confining potentials for tandem-mirror operations in GAMMA 10.

The main operations from 1979 to 2000 in the GAMMA 10 tandem-mirror, characterized in terms of the high-potential mode having kV-order plasma-confining potentials and the hot-ion mode yielding fusion neutrons with 10-20 keV bulk-ion temperatures, are summarized and generalized as a result of scalings of the formation and the effects of the potentials. The wide validity of potential-formation physics from Cohen's theory and the validity of the generalized Pastukhov's theory for the effects of thermal-barrier potentials on electron confinement are verified and consolidated through electron-energy balance.

Journal Article↗
PubMed2001

Three-color flow cytometric study on lymphocytes derived from thymic diseases.

BACKGROUND: Anterior mediastinal masses derive from a variety of diseases. Thymomas have been shown to commonly hold CD4(+)CD8(+) double-positive (DP) lymphocytes, and identification of this subset by two-color flow cytometric study was suggested to help diagnosis of thymoma. Several other thymic diseases, however, possibly hold CD4(+)CD8(+) DP lymphocytes. In this study, we utilized the three-color flow cytometric method for further examination of the phenotypes of lymphocytes in the thymic diseases. MATERIALS AND METHODS: One hundred eight specimens (77 primary and 10 metastatic thymomas, 10 thymic carcinomas, 2 thymic carcinoids, 4 malignant lymphomas, 2 seminomas, an inflammatory pseudotumor, and 2 nonneoplastic thymic hyperplasias) were subjected to the study. The expressions of CD3, CD4, and CD8 on tumor-associated lymphocytes were evaluated by three-color flow cytometric study. RESULTS: The proportion of the CD4(+)CD8(+) DP subset was more than 30% in all 78 lymphocyte-rich thymomas, in 2 malignant lymphomas, and in both thymic hyperplasias. CD3 expression of the CD4(+)CD8(+) DP subset ranged from a negative to a high level in thymomas and thymic hyperplasias, while it was restricted to a particular level in CD4(+)CD8(+) DP-type malignant lymphomas. The proportion of CD3(+) cells in the CD4(+)CD8(-) single-positive subset was consistently less than 90% in the lymphocyte-rich thymomas, while it was more than 90% in the thymic hyperplasias. CONCLUSION: Although identification of the CD4(+)CD8(+) DP subset in the tumor-associated lymphocytes does not necessarily indicate thymoma, a further characterization of thymic neoplasms possessing the CD4(+)CD8(+) DP subset was enabled by three-color flow cytometric study, suggesting the utility of this method as an ancillary tool for differential diagnosis of these diseases.

CD3 Complex↗
PubMed2001

Mediastinal liposarcoma appearing as a tumor arising in the esophageal wall.

We report a case of mediastinal liposarcoma, a relatively uncommon neoplasm, in which the mass also appeared as a tumor arising in the esophageal wall. A 76-year-old man diagnosed with a posterior mediastinal mass had the tumor extirpated in local esophageal myectomy due to its unclear margin on the esophageal wall. The resected specimen was diagnosed as well-differentiated liposarcoma. Preoperative angiography showed the tumor received its blood supply from a branch of the left gastric artery, suggesting it arose in the lower esophageal segment close to the hiatus and extended to the mediastinum. Since this tumor's growth pattern differed completely from esophageal liposarcoma described in previous case reports, we concluded that it was mediastinal liposarcoma.

Aged↗
PubMed2001

Single lung transplantation from a brain-dead donor for a patient with idiopathic pulmonary fibrosis. A breakthrough after new legislation in Japan.

Two single lung transplants from a single cadaveric donor were successfully conducted at 2 institutions on March 29, 2000, the first such procedure in Japan under newly introduced legislation. Our patient was a 48-year-old woman with idiopathic pulmonary fibrosis who underwent left single-lung transplantation under cardiopulmonary support. The donor lung was preserved in 4 degrees C modified Euro-Collins solution. Total ischemic time was 5 hours and 37 minutes. The postoperative course was uneventful. The patient was discharged on postoperative day 62 with satisfactory respiratory function.

Brain Death↗