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Biomedical subjects

T Misaki

Publications and source records attributed to T Misaki.

370 records · Page 21Linked to original sources

Bronchial artery embolization for hemoptysis: immediate and long-term results.

The purpose of this study was to evaluate the immediate and long-term results in 63 patients who underwent transarterial embolization for control of hemoptysis. Overall immediate success rate was 86.1%. At long-term follow-up 50% of patients showed complete remission, 22% partial remission, and 28% recurrent hemoptysis. Hemoptysis remained controlled for a mean of 22 months and a median of 14 months. The long-term results among four disease groups differed substantially. Patients with bronchiectasis showed the best results, followed by those with idiopathic disease and with inflammation; patients with neoplasm showed the worst results.

Adult↗

Optimal scan delay of arterial phase scanning of hepatic CT using a real-time image reconstruction system.

To optimize scan delay of arterial phase scanning of hepatic CT, 30 patients suspected of having HCC were examined using real-time image reconstruction technology (SureStart). In all cases, SureStart was successful. Despite the low dose, these images allowed adequate visualization of the abdominal aorta. The mean delay from the initiation of contrast administration to the beginning of arterial phase scanning was 29.6 +/- 5.2 sec (mean +/- SD; range, 22-51 sec).

Adult↗

Solitary lung tumors and their spontaneous metastasis in athymic nude mice orthotopically implanted with human non-small cell lung cancer.

We examined the tumorigenic and metastatic potentials of three human non-small cell lung cancer (NSCLC) cell lines, PC-14, A549 or Lu-99 cell lines suspended in Matrigel-containing phosphate-buffered saline were orthotopically implanted into the lungs of nude mice. The formation of a solitary tumor nodule in the lung was observed after the implantation of all cell lines. Intrapulmonary implantation of PC-14 or Lu-99 cells resulted in spontaneous distant metastases. In contrast, A549 cells caused multiple intrapulmonary metastases to the right and left lobes of the lung without producing visible lymphatic metastasis. We also investigated the expression of matrix metalloproteinases (MMPs), urokinase-type plasminogen activator (u-PA), u-PA receptor (u-PAR) and c-MET in these cell lines in vitro and in vivo. Reverse transcription polymerase chain reaction (RT-PCR) analysis showed that the expression of MMP-2 and membrane-type 1 MMP (MT1-MMP) was elevated in PC-14 as compared with the other two cell lines. In contrast, stronger expression of c-MET was observed in A549 than in PC-14 or Lu-99. These results indicate that differential patterns of metastasis of lung cancer might be associated with differential expression of metastasis-associated molecules. Our orthotopic implantation models display clinical features resembling those of NSCLC, and may provide a useful basis for lung cancer research.

Adenocarcinoma↗

Helical CT of the liver with computer-assisted bolus-tracking technology: scan delay of arterial phase scanning and effect of flow rates.

PURPOSE: The purpose of this work was to assess the scan delay and the effect of flow rates on arterial phase scanning of hepatic CT. METHOD: One hundred twenty patients suspected of having hepatocellular carcinoma were examined by three-phase helical CT using computer-assisted bolus-tracking technology. We set the region of interest (ROI) in the abdominal aorta at the level of the celiac artery as a baseline. The triggering threshold was set at 100 HU. A volume of 100 ml of iomeprol (350 mg of I/ml) was administered at 2, 2.5, or 3 ml/s i.v. RESULTS: In all cases, helical CT scanning began after reaching the ROI threshold. Then, portal venous phase scanning was initiated 50 s after arterial phase initiation. The mean delay time from the initiation of contrast agent administration to the beginning of arterial phase scanning was 29.2 +/- 3.8 s (mean +/- SD, range 22-39 s). A faster injection rate significantly shortened the scan delay (p < 0.01). In portal venous phase scanning, calculated areas under the hepatic enhancement curves were almost equal among different injection rates. CONCLUSION: The computer-assisted bolus-tracking technology is a useful method for determining an individual scan delay of arterial phase CT.

Aged↗

Real-time ultrasonography of thyroid nodules.

Sonographic characteristics were analyzed in 141 histologically confirmed thyroid nodules including 84 benign and 57 malignant tumors. Seven items were examined: Presence of a 'halo'; presence of cystic components; presence of calcification; hypoechogenicity; heterogeneity of the internal echo pattern: irregular or obscured margin; and massive extrathyroidal extension. Only the last-mentioned item appeared exclusively, but not very often, in malignant lesions, and the other characteristics were encountered in both benign and malignant lesions. Although ultrasonography is a method of choice for the evaluation of thyroid nodules, its ability to distinguish benign from malignant lesions is limited.

Calcinosis↗

Electrolyte disturbances caused by intravenous contrast media.

The changes in serum electrolytes (sodium, potassium, ionized calcium, and total calcium) produced by high-dose (3 ml/kg) intravenous contrast media were investigated in Japanese white rabbits. The test solutions included sodium/meglumine diatrizoate (370 mgI/ml), sodium/meglumine ioxaglate (320 mgI/ml), iohexol (350 mgI/ml), iopamidol (370 mgI/ml), 20% mannitol, and isotonic saline. The alterations in serum ionized calcium were relatively small and transient, and correlated with changes in the hematocrit. Diatrizoate caused a significant decrease in ionized calcium in comparison with other contrast media and mannitol. The ratio of ionized calcium to total calcium showed no significant decrease in any group. The changes in potassium did not correlate with those in hematocrit. Diatrizoate caused a smaller decrease in potassium than low-osmolality contrast media, which may suggest that diatrizoate caused a shift in potassium from extravascular space to intravascular space. In conclusion, intravenous infusion of high doses of low-osmolality contrast media did not cause clinically significant alterations in serum electrolytes.

Animals↗

A muscle powered cardiac assist device for right ventricular support: total assist or partial assist?

A muscle powered cardiac assist device (MCAD) for right ventricular support requires optimized diastolic filling to obtain full stroke and acceptable fluid dynamics. A valved and spring-assembled skeletal muscle ventricle (SMV) was designed as a prototype MCAD, regardless of fluid dynamics. The present study addresses the optimal bypass method for right ventricular support, and predicts the future design for an implantable MCAD. Latissimus dorsi muscle (LDM) of 11 dogs were conditioned electrically for a one year maximum, and transformed into fatigue-resistant muscles (Type I fibers). Superior and inferior vena cavae were anastomosed using one arm of a Y-shaped vascular graft, as an inflow conduit, and the outflow conduit was placed on the main pulmonary artery. SMV was wrapped with transformed LDM and the bypass method was varied by SVC and/or IVC ligation. SMV demonstrated sufficient right ventricular support on total bypass (70% compared with control output), and the maximum pump off-to-on flow ratio (200%) was obtained. Maximum SMV power output was 0.27 X 10(6) erg, which was equivalent to that of canine right ventricle. Right atrial-to-pulmonary artery bypass was also constructed by using SMV in another 14 dogs, and also showed that total bypass was preferable for optimal SMV diastolic filling. In conclusion, specific requirements for a future MCAD include a subsystem assembly such as a spring, magnet, or alternative auxiliary muscle pump assembly for MCAD filling, and total bypass with optimized fluid dynamics and anatomic fitting.

Animals↗

Surgical treatment of Wolff-Parkinson-White syndrome combined with variant angina pectoris.

Seven patients with coexistent Wolff-Parkinson-White (WPW) syndrome and variant angina pectoris underwent surgical interruption of an accessory atrioventricular conduction pathway. In two of these patients, perioperative coronary artery spasm occurred. One patient had a perioperative myocardial infarction and the other patient treated successfully had no infarction. Nitroglycerin and nifedipine were administered during and following operation in the other 5 patients without perioperative coronary artery spasm. No adverse effect was observed in the intraoperative electrophysiological study. Combined therapy of intravenous nitroglycerin administration and sublingual nifedipine administration are useful in the perioperative management of patients with coexistent WPW syndrome and variant angina pectoris.

Adult↗