Biomedical subjects
Publications and source records attributed to T Misaki.
We describe the case of a 45-year-old woman with a ureterocolic fistula caused by colonic diverticulitis. She had a 10-year history of intermittent left flank pain that had not been treated. The fistulous tract between the left ureter and sigmoid colon was confirmed by retrograde urography and a barium enema. A nephroureterectomy was successfully performed.
Radiofrequency (RF) catheter ablation has been used for the treatment of ventricular tachycardia (VT), however, in some patients VT might result from subepicardial macroreentry that could be successfully terminated by epicardial approach. This study examined the feasibility of thoracoscopic RF ablation of myocardium from epicardium using a custom made electrode. In five mongrel dogs, the thoracoscope was introduced through the 7th intercostal space. A 500-KHz continuous wave RF energy was connected to a custom made multiple electrode probe. Under thoracoscopic guidance, the heart was exposed and the RF probe was introduced. RF ablation was performed on the nonvascular ventricular wall of the beating heart. The left ventricular free wall and right ventricular outflow tract were satisfactorily visualized and ablated. The total dose of RF energy ranged from 50 to 500 J, and the estimated volume of ablated lesions ranged from 41.0-799 mm3. There were significant correlations between the RF discharge output and the irradiated lesion volume (P < 0.01), and the depth of the lesions (P < 0.01). Grossly, after RF ablation the ventricular myocardium demonstrated a circular, well-demarcated area of thermal injury. Volume and depth of the lesion depended upon the total dose of delivered RF energy. Thoracoscopic RF ablation appears to be a minimally invasive and useful method for creating irradiated myocardial lesions from epicardial surface. This method could be technically feasible for the treatment of Vts for which endocardial RF ablation is ineffective.
A new instrument for the immobilization and hemostasis of an anastomotic site during off-pump bypass is described. The instrument called "MIDCAB doughnut" was used safely and accurately in 31 patients who underwent MIDCAB without CPB. In these, the instrument was applied in 44 anastomotic sites on the beating heart (30 left anterior descending, 7 right coronary, and 7 obtuse marginal arteries). It can make an operative field motionless and bloodless without distal snaring, because of air sucked fixation of an entire circuit of the anastomotic site. There was no operative and hospital deaths. Postoperative angiography revealed a 100% patency rate of the grafts. MIDCAB doughnut can improve a quality of the anastomosis during beating bypass surgery.
BACKGROUND: Single-vessel coronary bypass grafting of the left internal thoracic artery (LITA) to the left anterior descending coronary artery (LAD) with mini-thoracotomy has been shown to produce excellent results with almost no mortality. However this procedure cannot be used in patients with double or triple vessel disease. METHODS: Between Aug. 96 and Dec. 97, 17 pts underwent minimally invasive direct coronary artery bypass (MIDCAB) to right (RCA) and circumflex coronary artery (CX). LITA and RITA were thoracicscopically harvested and the right gastroepiploic artery (RGEA), inferior epigastric artery, and radial artery were then harvested. A limited left thoracotomy in combination with limited anterior right thoracotomy (n = 3) or right lower parasternal incision extending to below the xiphoid process (n = 6) were made. The double MIDCAB as performed in 16 pts and triple in 1 pt. RESULTS: There was no operative death. At follow up, all pts are alive and well. The postoperative angiographic studies showed 30/31 grafts were patent. CONCLUSION: The utility of multi-vessel MIDCAB for the LAD, CX and RCA with in-site arterial grafts has been demonstrated in the present study. This less invasive surgical technique may become a viable option for the management of multi-vessel coronary artery disease.
A 68 year-old woman underwent replacement of the descending thoracic aorta with a cryopreserved aortic homograft for the treatment of a Stanford B dissecting aneurysm. After surgery, the patient made an uneventful recovery without recurrent infection. In such cases, the use of aortic homografts to replace aortic segments is a promising and effective therapeutic option.
The purpose of this study was to examine the efficiency to use by the thin thoracoscope for the palmar hyperhidrosis. General anesthesia with double lumen endotracheal intubation was used in all cases. A 2 mm incision made in the anterior axillary line in the third intercostal space. Pneumothorax was obtained by insufflation 1.5-2 L of CO2. A 2 mm endoscopic trocar was inserted through this incision, and a 2 mm, 0-degree scope (Autosuture, USA) was introduced. A second 2 mm trocar was inserted in the middle axillary line in the fourth intercostal space, through which a straight endoscopic seizer was introduced. The chain was dissected by electrocutting the white and gray rami and was incised over the second and third ribs. To avoid puemothorax, 8 F thoracic catheter was introduced through a guide wire which was inserted through a 2 mm trocar. The lung was expanded, and then the thoracic catheter was removed. We performed six sympathectomies on three female patients. All patients was satisfied of their results. This technique used by thin thoracoscope was cosmetic and a skin incision did not need to close too small.
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To develop a new method of radioimmunodetection for thyroid cancer, we tested the binding ability of a human antithyroglobulin monoclonal antibody, VB5, to primary culture of human thyroid cancer cells. VB5 was able to immunostain cytoplasmic thyroglobulin (Tg) in the acetone-fixed cancer cells when used in a labeled streptavidin-biotin method but not in a conventional indirect immunoperoxidase technique. The antibody was readily labeled with I-125 in the standard chloramin-T method, and showed specific binding to the antigen on cultured malignant thyrocytes displaceable with non-labeled VB5 or with excess Tg antigen. Although these initial results in vitro are encouraging, the observed low specific binding (about 1% at room temperature) to intact cells with a single monoclonal antibody seems insufficient to conduct any in vivo immunolocalization experiments in animals. To obtain more binding, we would need a cocktail of several monoclonal antibodies to different epitopes, and also fragmentation of antibody molecules to penetrate into cytoplasm.
In order to elucidate causes of subclinical thyrotoxicosis, we reviewed records of thyroid function tests obtained in our hospital between 1990 and 1992 showing normal thyroid hormones and subnormal TSH levels, and analyzed underlying clinical conditions of the patients. Of 186 patients with normal T4 and/or free T4 and normal T3 and/or free T3 but subnormal TSH (< 0.1 mU/l) levels in serum, 150 were under treatment with antithyroid drugs for hyperthyroid Graves' disease or with thyroid hormones for hypothyroidism. Twelve were in remission after treatment for Graves' disease, and 4 had destructive thyroiditis. Of the remaining 20 patients, 4 had autonomously functioning thyroid nodule (AFTN), 9 had euthyroid ophthalmic Graves' disease (EOG), and 7 had diffuse goiter without apparent ophthalmopathy (DG). When thyroid stimulating antibodies (TSAb) were measured in the last 3 groups of the patients, they were detected in none with AFTN but in all patients with EOG and DG. These 7 DG patients without ophthalmopathy had a clinical feature showing unstable thyroid functions, changeable to euthyroidism, overt hyperthyroidism and even hypothyroidism during follow-up. In conclusion, TSAb measurement is useful for detection of subclinical Graves' disease in euthyroid subjects with subnormal TSH levels in serum.
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OBJECTIVE: Pulmonary hypertension and transient graft dysfunction may complicate the postoperative course of patients undergoing lung transplantation. Recent studies have suggested that ischemia followed by reperfusion impairs release of endothelium-derived nitric oxide (NO). We investigated the acute effect of inhaled NO on hemodynamics and the oxygen free radical scavenger system after reperfusion following lung ischemia. METHODS: Fourteen anesthetized mongrel dogs were ventilated mechanically. After median sternotomy the left lung was rendered ischemic by totally clamping the left pulmonary hilum. After 90 min, the left lung was reperfused for 150 min by unclamping of the left hilum and clamping the right pulmonary hilum so that all pulmonary blood flow was directed to the left lung. Seven dogs inhaled 30 parts per million (ppm) NO during reperfusion (NO group); the other seven dogs were ventilated without NO inhalation (control group). Hemodynamics, gas exchange, superoxide dismutase activity and lipid peroxide of pulmonary venous blood, and wet/dry ratio of reperfused lung were measured. RESULTS: Neither of the two groups showed any change in systemic blood pressure prior to or following reperfusion. Immediately after reperfusion, mean pulmonary arterial pressure was significantly less (23.2 +/- 4.2 mmHg) in the NO group than in the control group (32.7 +/- 5.8 mmHg), as had been throughout reperfusion. Pulmonary vascular resistance and right ventricular end diastolic pressure were lower after reperfusion in the NO group. Superoxide dismutase activity after reperfusion in the control group significantly decreased to 41% of preischemic value. In the NO group, however, no decrease was seen and a significantly higher value was observed. The wet/dry ratio of reperfused lung was 5.47 +/- 0.52 in the control group and 4.72 +/- 0.36 in the NO group, with decreased pulmonary moisture noted in the NO group. There was no difference in lipid peroxide between the two groups. CONCLUSION: NO inhalation suppressed pulmonary hypertension after reperfusion following lung ischemia without affecting systemic arterial pressure. As superoxide dismutase activity was not depressed in the NO group, NO inhalation might enhance suppression of oxygen free radicals. These findings suggest that NO inhalation may be therapeutically useful after lung transplantation.
Detectability of bone metastases from differentiated thyroid carcinoma by technetium-99m hydroxymethylene diphosphonate ([99m]Tc-HMDP) bone scan is considered to be poor. Thallium-201 (201Tl) is also widely used for detecting metastatic lesions. Our present study was aimed at the evaluation of the combined use of (99m)Tc-HMDP and 201Tl imaging in successful detection of bone metastases from differentiated thyroid carcinoma. Twenty-seven thyroidectomized thyroid cancer patients (19 females, 8 males; 12 papillary type, 15 follicular type) with 77 bone lesions were included in this retrospective study. All of these patients received ablative doses of radioiodine. Thyroidal origin of the lesions was proved by positive iodine-131 (131I) uptake. In 131I-negative lesions, histological proof or absence of tumor markers other than thyroglobulin was considered when computed tomography (CT) and/or magnetic resonance imaging (MRI) suggested metastatic nature of the lesions. Of the 77 lesions, 58 (75.3%) were positive and 19 were negative in the (99m)Tc-HMDP bone scintigraphy, whereas 53 lesions (68.9%) could be detected by 201Tl scintigraphy. However, within the 19 (99m)Tc-HMDP-negative lesions, 14 showed abnormal accumulation of 201Tl, and within the 24 201Tl negative lesions, 19 were positive in (99m)Tc-HMDP scan. This resulted in a combined sensitivity of 93.5%. Our present study concludes that combined (99m)Tc-HMDP and 201Tl imaging is a sensitive and effective method for detecting bone metastases from thyroid carcinoma.
We evaluated postoperative myocardial enzymes and function associated with cryoablation in 20 patients with Wolff-Parkinson-White syndrome undergoing surgical treatment for a single left-sided accessory conduction pathway. Ten patients underwent endocardial atrial incision with cryoablation using CO2 at -60 degrees C for 120 sec (group A), while the remaining 10 patients did not receive cryoablation (group B). Levels of aspartate aminotransferase (GOT), lactate dehydrogenase (LDH), and creatine kinase (CK-MB) on postoperative days 1, 2, and 3 were higher in patients in group A than in group B (p < 0.05). However, mean values remained low (GOT, 120.5 IU/L; LDH, 1105.1 IU/L; CK-MB, 76.3 IU/L). No electrocardiographic changes were detected. Parameters of cardiac function, including cardiac index, stroke volume index, systemic vascular resistance, and ejection fraction, remained unchanged during the postoperative period in both groups. Furthermore, 201Tl cardiac scintigraphy demonstrated no evidence of myocardial perfusion defects due to cryoablation in group A. In conclusion, myocardial damage induced by cryoablation is very minor and is not associated with any clinical impairment of cardiac function.
OBJECTIVE: To develop a novel bioassay for the assessment of thyroid cell growth stimulating activity using cytochalasin B (CB) and to test immunoglobulins (IgGs) from patients with autoimmune thyroid diseases. DESIGN: The assay is based on the principle that growing cells during incubation with CB show an increased number of nuclei in a cell (N/C index), since CB, at appropriate concentrations, is known to inhibit cytoplasmic cleavage without affecting nuclear mitosis. The N/C index represents potential DNA production while cells are incubated with CB. METHODS: FRTL-5 thyroid cells were incubated with various thyroid stimulators in TSH-free medium containing 2 mg/J CB for 3 days. After the incubation, the cells were harvested in trypsin/EDTA to obtain single cell suspension, fixed, dropped onto a glass slide, stained and observed under a microscope to determine the N/C index. RESULTS: Bovine TSH at 10(-3)-1.0 U/I, forskolin at 1x10(-7)-10(-5) mol/l, cholera toxin at 10x10(-5)-10(-3) mg/l, or (Bu)2cAMP at 1 x 10(-5)-10(-3) mol/l increased the N/C index up to approximately 2.0 in a dose-dependent manner. IgGs not only from 27 patients with untreated goitrous Graves' disease but also from 14 patients with goitrous Hashimoto's thyroiditis elicited an increase in the N/C index, which exceeded the mean + 2 S.D. of the values for 17 normal subjects (mean +/- S.D., 1.063 +/- 0.014). Four patients with primary myxedema displayed a normal N/C index. In Graves' disease, the N/C index did not correlate significantly with thyroid stimulating antibodies (TSAb) activities but did correlate significantly with estimated goiter size (P < 0.05). IgGs containing blocking-type TSH-receptor antibodies inhibited the TSH- or Graves IgG-stimulated increase in N/C index almost completely, but did not influence the stimulatory effect of IgG from two patients with Hashimoto's thyroiditis. CONCLUSIONS: We have developed a sensitive and simple assay for thyroid growth stimulating activity by using CB, and found that all tested patients with goitrous Graves' disease and goitrous Hashimoto's thyroiditis have thyroid growth stimulating immunoglobulins whose activity does not correlate with TSAb.
UNLABELLED: Technetium-99m-methoxyisobutyl isonitrile (99mTc-MIBI) was evaluated for its ability to detect metastases from thyroid carcinoma. METHODS: Twenty-seven thyroidectomized patients with metastatic differentiated thyroid carcinoma, of whom 20, 9 and 12 had lung, lymph node and bone metastases, respectively, were examined with 99mTc-MIBI. The scan results were compared with those of 201TI and 131I whole-body scans. RESULTS: Increased accumulation of 99mTc-MIBI was observed in lung metastases of 15 patients (75.0%), 12 lymph node metastases (100.0%) and 29 of 31 bone metastases (93.5%). Increased accumulations of 201TI and 131I scans were seen in, respectively, 16 (80.0%) and 17 (85.0%) of the 20 patients with lung metastases, 12 (100.0%) and 5 (41.7%) of the 12 lymph node metastases and 28 (90.3%) and 27 (85.1%) bone metastases. Because of its better image quality, 99mTc-MIBI detected more lesions in the lung (n = 38) than 201TI did (n = 17). CONCLUSION: Technetium-99m-MIBI is clinically useful for detecting metastases from differentiated thyroid carcinoma and deserves clinical application in the postoperative follow-up of such patients.
The patient, a 48-year old male, was seen with hoarseness in December 1990. A chest radiograph and chest CT scan showed an anterior mediastinal mass. Median sternotomy revealed epithelial thymoma with involved partial lung and pericardium. After surgery, he received external radiation to the mediastinum. One year later he was given another 40 Gy external radiation in the cervical and mediastinal recurrence region. In May 1994, a chest CT scan revealed an extrapleural and bilateral lung mass. Histological examination revealed recurrent epithelial thymoma in the left cervical muscle biopsy, so treatment with cyclophosphamide and prednisolone were begun. A dose of 100 mg/body/day of cyclophosphamide and a dose of 10 mg/body/day of prednisolone were administered every 2 week. Complete remission was induced with four cycles of this treatment of cyclophosphamide and prednisolone. The chemotherapy was thus continued for 20 cycles in 14 months. This chemotherapy with cyclophosphamide and prednisolone appeared to be useful and safe for recurrent thymoma at the outpatient clinic level.
We examined the amount and method of administration of midazolam and fentanyl for intravenous anesthesia. Intravenous anesthesia was induced by intravenous administration of fentanyl 0.2-0.3 mg, followed by a minimal sleeping-inducing dose of midazolam, and then an additional 0.2 mg of fentanyl before starting the operation. To maintain anesthesia, a half dose of the first dose of midazolam was administered every hour, and a continuous intravenous injection of fentanyl at 0.08 microgram-1. kg-1.min-1 was also performed. It is suggested that these doses are the most suitable for obviating the use of antagonist. Also, by using a continuous administration, the dose of fentanyl can be reduced, and it is possible to stabilize circulation. Without the use of nitrous oxide during intravenous anesthesia, it is necessary to double the dose of fentanyl administered.