Biomedical subjects

T Misaki

Publications and source records attributed to T Misaki.

At least 109 records · Page 6Linked to original sources

PubMed1996

[Three-phase dynamic helical CT for hepatocellular carcinoma: optimal scanning protocol].

To assess the optimal scanning protocol for three-phase dynamic helical CT, 20 patients were examined according to the following 4 methods (5 cases each) : (1) 100 ml Iopamidol (300 mgI/ml), at a rate of 2 ml/sec ; (2) 120 ml,3 ml/sec, (3) 150 ml, 3 ml/sec ; (4) biphasic method, initial 100 ml, 3.3 ml/sec ; remaining 50 ml, 1.6 ml/sec. Assessment of the time-density curve of the aorta, and the liver parenchyma, indicated that protocol (4) was superior to the others. Using protocol (4), 32 patients (62 nodules) with hepatocellular carcinoma underwent three-phase scanning, consisting of early, late, and delayed phases. Out of 61 nodules, 43 nodules were detected as high density areas in the early phase, 7 nodules as low density areas only in the late phase, and 3 nodules as low density areas only in the delayed phase. Compared with MRI, three-phase dynamic helical CT demonstrated numerous nodules, especially those less than 10 mm in diameter, and, therefore, was useful for the detection of hepatocellular carcinoma.

Aged↗

PubMed1996

[Emergency coronary artery bypass grafting under cardiopulmonary resuscitation: a successful case report].

A successful case of emergency coronary artery bypass grafting for a 69-year-old man with refractory cardiac arrest due to impending myocardial infarction was reported. Preoperative full resuscitation including external cardiac massage was required. The duration from cardiac arrest to cardiopulmonary bypass establishment was 24 minutes and aortic cross clamping time was 29 minutes for triple bypass grafting to the right, left circumflex and left anterior descending coronary artery.

Aged↗

PubMed1996

[The changes in lymphocytes subpopulations of a patient with postoperative chylothorax].

A case of 64-year-old male who developed chylorrhea at 2 days post coronary artery by-pass grafting, is reported. He was managed conservatively for 3 weeks. But chylothorax was not improved, he was treated operatively. Analysis of his lymphocyte subpopulations in peripheral blood were performed during the course of chylothorax. Lymphocytepenia became apparent and subpopulation of T cell were decreased gradually. The subpopulation of CD 4(+) cell decreased, while the subpopulation of CD 8(+) increased. The CD 4(+) cell/CD 8(+) cell ratio decreased consequently till 7th day after 2nd operation. Although the replenishment of nutritional deficiencies using TPN allows prolonged conservative management for chylothorax patient, the deterioration in cellular immunocompetence can not be prevented at present. It is necessary to take great care about infection for chylothorax patient.

CD4-CD8 Ratio↗

PubMed1996

[Removal of complete type of mediastinal goiter in thirty-six-year-old female--a case report].

A tumor 6 cm in diameter located in the anterior superior mediastinum was found in a 36-year-old female, initially detected on chest-X-ray film in mass screening. The tumor was positively shown by 201thallium chloride scintigram. It was removed, and rapid diagnosis by frozen section proved benign. Follicular adenoma, with no connection to the thyroid, was diagnosed. It was a complete type of mediastinal goiter. Considering quality of life (QOL) as a 36-year-old female, the approach is important. Right half collar incision and upper median sternotomy from the top to the 3rd intercostal space was performed. Because few difficulties were experienced in removing the tumor, this case suggested that the incision and approach has usefulness to keep QOL.

Adenoma↗

PubMed1996

[Successful scartectomy and cryoablation for ventricular tachycardia occurring late after correction of tetralogy of Fallot].

A 26-year-old man had a total repair of tetralogy of Fallot at 1 year of age, and had redo surgery for restenosis of the right ventricular outflow tract and small residual VSD at 11 years of age. After the second operation, AV block developed and an endocardial pacemaker system was implanted. For the last 3 years, he had mild febrile episodes, cough, occasional hemoptysis and paroxysmal ventricular tachycardia. Because of his refractory tachycardia and suspected infective endocarditis, he was admitted for further study. Blood culture revealed Peptostreptococcus, echocardiogram showed vegetation around intravenous pacing lead, and electrophysiological study demonstrated delayed potential on the left side of the right ventricular outflow tract. He underwent scartectomy and cryoablation of the focus of the tachycardia which was reconfirmed by epicardial and endocardial mapping during the operation, which involved removal of the endocardial lead and new outflow tract patch repair. His postoperative course was uneventful without any antiarrhythmic drugs. Pathological examination of the scar showed myocardial fibrosis and replacement by fatty tissue which was different from the pathological characters of the arrythmogenic right ventricular dysplasia.

Adult↗

PubMed1995

Two consecutive nucleotide substitutions resulting in the T3 receptor beta gene resulting in an 11-amino acid truncation in a patient with generalized resistance to thyroid hormone.

We identified unusual mutations in the T3 receptor (TR) beta gene in a 6-year-old Japanese girl with generalized resistance to thyroid hormone. Two consecutive base substitutions, T to A and C to A at nucleotide positions 1637 and 1638, respectively, changed the 451st codon coding for Phe(TTC) to stop codon (TAA), resulting in an 11-amino acid carboxyl(C)-terminus truncation. The patient was a heterozygote. Western blotting using an anti-TR antibody demonstrated the truncated receptor protein. The patient showed severe mental retardation (IQ41), disturbance in speech development, and attention deficit hyperactivity disorder. Thyroid functional status by clinical evaluation was considered within the normal range in spite of high serum thyroid hormone levels (T4 725.9 nmol/l, T3 12.7 nmol/l, FT4 166.0 pmol/l). TSH increased from 0.6 to 24 mU/L after TRH (150 micrograms) injection. TSH secretion as well as 123I-uptake was suppressed only partially by T3 (75 micrograms/day for a week). Close examination of thyroid functions and TR beta gene analysis were not possible in the family, except for paternal grandmother and one of her two sisters who showed no abnormality. The patient's truncated TR beta showed very low T3 binding activity (Ka = 0.1 x 10-10 M), transcriptional activity, and a very strong dominant negative effect. When co-expressed with wild-type TR beta at the molar ratio 1:1 in CV-1 cells, the mutant receptor inhibited the wild-type TR beta transcriptional activity by 74% at 10 nM T3. Even 1 microM T3 could not normalize these impaired functions.

Amino Acid Sequence↗

PubMed1995

Changes in folate concentration in Yoshida sarcoma after administration of leucovorin or cisplatin.

Both leucovorin (LV) and cisplatin (cis-dichlorodiammine platinum II, CDDP) act as modulators of 5-fluorouracil (5-FUra) by increasing the intracellular concentration of reduced folate. We measured intracellular folate levels following the administration of LV or cisplatin in tumor-bearing rats to determine the optimal schedules for their use as 5-FUra modulators. Donryu rats were inoculated with Yoshida sarcoma cells on the right flank. Seven days after tumor inoculation, the animals were injected with LV or CDDP. The kinetic and dose-related changes in intracellular folate concentration were analyzed by means of a binding assay. Folate levels in the tumor tissues were significantly higher than baseline 1 and 2 h after administration of LV and remained significantly high until 8 h after administration. Folate levels in the tumor tissues were significantly higher than baseline 1 and 2 h after cisplatin administration, then decreased to a rather low level 8 h after, and to a significantly lower level than baseline 24 h after administration. The folate levels in the tumor tissue increased in proportion to the dose of LV, but did not increase when the dose of cisplatin was increased from 1 mg/kg to 8 mg/kg. Repeat high-dose administration of LV and repeat low-dose administration of cisplatin are advocated when they are used as modulators of 5-FUra.

Animals↗

PubMed1995

Efficacy of a skeletal muscle-powered dynamic patch: Part 1. Left ventricular assistance.

In this study, we examined the capability of a skeletal muscle-powered, dynamic patch to provide left ventricular assistance. An actuator was developed that used linear traction power furnished by the latissimus dorsi muscle and liquid as the medium for power transfer. The proximal portion of the muscle was dissected and was reattached to the actuator. The left ventricular apex was excised, and the dynamic patch lined with autologous pericardium was implanted during cardiopulmonary bypass. Hemodynamic studies were performed in 8 dogs after weaning from cardiopulmonary bypass. Muscle stimulation was found to significantly increase the systolic aortic pressure (91.6 versus 112.1 mm Hg; p < 0.01), the mean aortic pressure (65.2 versus 73.0 mm Hg; p < 0.01), and aortic blood flow (0.77 versus 0.92 L/min; p < 0.01). The left atrial pressure decreased from 17.9 to 16.6 mm Hg (p < 0.01). This "hybrid" left ventricular assist device possesses notable clinical advantages because of its remarkable efficacy in assisting circulation. Further experimental studies using preconditioned skeletal muscle are necessary to assess the long-term effects of this technique.

Animals↗

PubMed1995

Efficacy of a skeletal muscle-powered dynamic patch: Part 2. Right ventricular assistance.

The purpose of this study was to assess the feasibility of using a skeletal muscle-powered dynamic patch to assist the failing right ventricle. Seven adult mongrel dogs were used in the study. The proximal portion of the left latissimus dorsi muscle was harvested and reattached to the actuator to serve as a skeletal muscle energy convertor. The right ventricular free wall was fully excised and the dynamic patch was implanted under cardiopulmonary bypass. After weaning from cardiopulmonary bypass, the latissimus dorsi muscle was stimulated using a burst frequency of 33 Hz, a burst duration of 200 ms, and 1:2 synchronous mode stimulation with the native R wave. Latissimus dorsi muscle stimulation increased systolic aortic pressure (78 versus 91 mm Hg; p < 0.01), mean aortic pressure (56 versus 62 mm Hg; p < 0.05), aortic blood flow (0.73 versus 0.97 mL; p < 0.01), and systolic right ventricular pressure (41 versus 56 mm Hg; p < 0.01). The mean right atrial pressure decreased from 14 to 9.6 mm Hg (p < 0.01). Our results demonstrate that the use of a right ventricular dynamic patch powered by a skeletal muscle linear-type actuator can not only function as a right ventricular free wall substitute but also lead to the augmentation of right ventricular and global cardiac function.

Animals↗

PubMed1995

Surgical treatment of patients with Wolff-Parkinson-White syndrome and associated Ebstein's anomaly.

Ebstein"s anomaly is the most common congenital heart disease associated with the Wolf-Parkinson-White syndrome. Between November 1973 and March 1993, we surgically treated 42 patients with Wolff-Parkinson-White syndrome and Ebstein's anomaly. The patient's ages ranged from 5 months to 59 years (mean 35.3 +/- 14.0 years). There were a total of 52 accessory pathways, 48 of which were located in the right (65%) or posteroseptal (29%) area. A left-sided accessory pathway was seen in only two patients (3.8%). Division of all right-sided accessory pathways was done during normothermic cardiopulmonary bypass with the heart beating; cryocoagulation was applied together with scalpel dissection of the atrioventricular groove. Division of the left-sided accessory pathways was done with the use cold potassium cardioplegic arrest. Thirty-five of these patients underwent tricuspid valve operation for Ebstein's anomaly and 11 of them underwent tricuspid valve replacement with a bioprosthesis. All 52 accessory pathways were successfully divided, although two patients required reoperation because of tachycardia caused by accessory pathways in different positions. Three hospital deaths (7.1%) occurred. There were no late deaths during the follow-up period (mean 94.3 +/- 52.4 months), but two patients required repeat tricuspid operation because of progression of the tricuspid regurgitation. Because no repeat operations were required during long-term follow-up patients who underwent valve repair or valve replacement, correction should be indicated in some patients.

Adult↗

PubMed1995

Surgical treatment of atrioventricular atresia combined with Wolff-Parkinson-White syndrome.

BACKGROUND: Tachyarrhythmia has been thought to be an absolute contraindication for the Fontan operation. PATIENTS AND METHODS: Three patients, 22, 9, and 11 years of age, diagnosed as having atrioventricular atresia combined with the Wolff-Parkinson-White syndrome underwent surgical treatment. Each had drug-resistant atrioventricular tachycardia that required direct cardioversion. Two patients with tricuspid atresia had an intermittent right-sided accessory pathway (ACP), and one with mitral atresia had a concealed left-sided ACP. The ACP was divided using an epicardial approach in two patients and an endocardial approach in one. Simultaneously, the Fontan operation was performed with atrioventricular connection (modified Fontan operation) in one patient, and a total cavopulmonary connection performed in another patient. In the remaining patient, ACP division was performed 3 years after the Fontan operation. RESULTS: There was no early death or other fatal complication, and the hemodynamic results were excellent. During the mean follow-up period of 68 months (range, 5 to 127 months), there has been no late death or recurrence of tachyarrhythmia. CONCLUSION: Tachyarrhythmias caused by ACPs are not contraindications for the Fontan operation. Concomitant surgery is advocated, as excellent short- and long-term results may be expected in these patients.

Adult↗

PubMed1995

Augmentation of thyrotropin-induced iodide uptake in FRTL-5 cells by immunoglobulins containing blocking thyrotropin-receptor antibodies under NaCl-depleted conditions.

We have found recently that Graves' immunoglobulins (Igs) are more active under NaCl-free conditions to increase iodide uptake in FRTL-5 thyroid cells. The present study was designed to examine the effect of blocking-type thyrotropin (TSH)-receptor antibodies (TR-abs) in the same assay. FRTL-5 cells were incubated with crude Ig fractions from 13 patients with primary hypothyroidism having blocking TR-abs and 100 mU/l bovine TSH in NaCl-free Hanks' balanced salt solution (HBSS) supplemented with 274 mmol/l sucrose (HBSS(-)-sucrose) to keep isotonicity for 3 days, followed by the determination of 60 min of 125I uptake in the cells. Thyrotropin alone increased the uptake to 3.3- to 5.2-fold of the basal. When the highest concentration (250 ml serum equivalent (eq.)/l) of the Ig was used, the TSH-stimulated 125I uptake was decreased to 0-42% in 11 of the 13 cases. When the lower concentrations (0.4-50 ml serum eq./l) were used, however, 125I uptake was enhanced (1.4- to 11.4-fold) unexpectedly in all 13 cases. Such an enhancement was specific to blocking TR-abs, because the effect was duplicated by the purified IgG but not by Igs from 10 healthy control subjects or from three TR-ab-negative hypothyroid patients. When Graves' Igs, instead of TSH, were used as a stimulator, the similar stimulatory effect of the Ig with blocking activity was observed on the 125I uptake induced by three Graves' Igs but not on the response to one Graves' Ig. These Igs alone displayed no stimulating activity. When isotonic 5H medium was used instead of HBSS(-)-sucrose, effects of these 13 Igs were only inhibitory on the TSH-stimulated 125I uptake.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Myocardial oxidative metabolism in hyperthyroid patients assessed by PET with carbon-11-acetate.

UNLABELLED: Hyperthyroid patients often complain of cardiovascular symptoms because of increased metabolism. This study was designed to quantitatively evaluate myocardial oxidative metabolism in these patients. METHODS: Dynamic PET with 11C-acetate was performed in 19 patients who had not undergone treatment for hyperthyroidism. Eight were restudied 2 wk after oral administration of propranolol. The clearance rate constant of 11C-acetate (Kmono) was calculated with monoexponential fitting of tracer washout from the myocardium as a marker of myocardial oxidative metabolism. The results were compared with those in nine normal subjects both at rest and during dobutamine infusion. RESULTS: Kmono in our patients (0.109 +/- 0.028 min-1) was significantly increased compared to normal subjects (0.066 +/- 0.016 min-1) (p < 0.05). After propranolol treatment, Kmono decreased (0.082 +/- 0.014 min-1) but remained significantly higher in eight patients than normal subject levels (p < 0.05), while the rate pressure product decreased significantly (7500 +/- 1700) toward the normal range (7900 +/- 1500). CONCLUSION: These results suggest the possibility of excessive myocardial oxygen consumption in hyperthyroid patients. The clearance rate of 11C-acetate is a new and valuable index to assess myocardial oxidative metabolism not closely related to the pressure rate product or thyroid hormones in these patients.

Acetates↗

PubMed1995

[Composite arterial conduits with internal thoracic artery and inferior epigastric artery for a myocardial revascularization].

From November 1992 to February 1995, 10 patients were submitted to myocardial revascularization using composite arterial conduit with internal thoracic artery (ITA) and inferior epigastric artery (IEA). The age ranged from 48 to 68 years (mean age, 60.3 years); all patients were male. All patients had double-or triple vessel disease. The mean ejection fraction was 61.8% (range, 43 to 77%). We used 28 arterial conduits including 5 right ITAs, 10 left ITAs, 10 IEAs, and 3 right gastroepiploic artery. 10 IEAs were anastomosed to one ITAs and 10 composite arterial conduits were constructed (branched in 3, lengthened in 7). In 5 patients a double ITAs were used in a single patient. There was no operative mortality and fetal complication. Early postoperative angiographic controls demonstrated 100% patency of composite grafts in 9 of 10 patients. The composite arterial graft using ITAs and IEAs is feasible and the anastomoses so performed are completely safe.

Aged↗

PubMed1995

[Video-assisted lobectomy for primary lung cancer].

We had performed video-assisted lobectomy for six primary lung cancer cases. This report is presented our method of video-assisted lobectomy with a typical case. This case had a complain of positive sputum cytology at the regular examination. His chest rentogenogram was almost normal and the bronchoscopic appearance was revealed polypoid lesion at left B 3 orifice. His sputum cytology examined 3 years ago was positive. At that time we could not find the malignant site at the left B 3 orifice. So further examination was performed, but we did not find other metastatic site and mediastinal nodes involvement by chest computed tomography. Left upper lobectomy and lymph node dissection was performed by video-assisted thoracotomy with small lateral incision of about 8 centimeters on the fifth intercostal space and other two thoracotomy ports. This operation method was followed as same fashion as the standard lobectomy with double knotted pulmonary vein and artery without the usage of the automatic anastomotic device. His postoperative pathological study was revealed intramural bronchial cancer at B 3 orifice without node involvement. His postoperative course was uneventful. He had discharged at 18 postoperative day.

Carcinoma, Squamous Cell↗

PubMed1995

Long-term outcome of operative treatment of focal atrial tachycardia.

BACKGROUND: This study examined the long-term clinical outcome of patients with focal atrial tachycardia who were treated surgically. Focal atrial tachycardia is a relatively rare arrhythmia that is often difficult to control with conventional medical therapy. Therapeutic modalities are not well defined because of the scarcity of long-term data of treated patients, including pathologic findings. STUDY DESIGN: Nine patients, six men and three women, ranging in age from 16 to 50 years (mean of 34 +/- 14 years), underwent operative treatment for focal atrial tachycardia. The average rate of tachycardia was 167 +/- 22 beats per minute. All patients were treated with antiarrhythmic drugs (mean 2.9 drugs per patient). Concomitant operative procedures were performed upon four patients, including division of the accessory atrioventricular pathway for the Wolff-Parkinson-White syndrome in two patients, plication of the right atrium for idiopathic right atrial dilatation in one patient, and a closure of the atrial septal defect in one patient. Focal ablation was performed in all instances. RESULTS: There was no early or late death nor postoperative complications. Atrial tachycardia disappeared and there were no episodes of recurrent tachycardia postoperatively during the mean follow-up period of 67 +/- 38 months. Histopathologic findings from four patients revealed a sinus node-like structure, diffuse chronic epimyocarditis, focal myocarditis, and fascicular disarray lesions. CONCLUSIONS: Excellent long-term result were obtained in patients with focal atrial tachycardia who were treated operatively. Early operative intervention is preferable before the occurrence of impaired ventricular function. From the histopathologic findings, operative therapy should be selected in patients with diffuse atrial lesions.

Adolescent↗

PubMed1995

[Usefulness of body surface potential maps to determine ablation site in patients with WPW syndrome].

We studied body surface potential maps (BSPM) in patients with WPW syndrome before surgical ablation. These BSPM were compared with computerized epicardial mapping using sock and snap electrode. In most patients the location of minima in the early delta wave was a simple and accurate index of the site of accessory pathway. In 4 patients BSPM was useful for the diagnosis of presence of bilateral accessory pathways. We conclude that BSPM may be also useful to determine ablation site of radiofrequency catheter ablation.

Body Surface Potential Mapping↗

PubMed1995

Effects of clonidine on intravenous sedation with midazolam.

The effect of clonidine, an alpha 2-adrenoceptor agonist, on intravenous (IV) sedation with midazolam was studied. Subjects were eight healthy adults; IV sedation was performed twice on each subject. In the control (CO) group, midazolam alone was administered. In the clonidine (CL) group, the subjects were given about 5 micrograms/kg of clonidine orally 2 hr before the initiation of sedation with midazolam. The following parameters were determined: dose of midazolam, changes in vital signs, recovery time, amnesia, and side effects. The average sedating dose of midazolam was 0.078 and 0.043 mg/kg in the CO and CL groups, respectively. Recovery times determined by stabilometry were 150 and 120 min in the CO and CL groups, respectively. Based on these results, the combined use of clonidine can reduce the dose of midazolam and shorten the recovery time. It is suggested that clonidine may be useful in IV sedation with midazolam.

Adrenergic alpha-Agonists↗